foo
verb is ListRecords
2015-07-28T13:13:59Z
http://oai.repec.openlib.org/oai.php
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:242-2502011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:242-250
article
Algorithms of common solutions for variational inclusions, mixed equilibrium problems and fixed point problems
In this paper, we present an iterative algorithm for finding a common element of the set of solutions of a mixed equilibrium problem and the set of fixed points of an infinite family of nonexpansive mappings and the set of a variational inclusion in a real Hilbert space. Furthermore, we prove that the proposed iterative algorithm has strong convergence under some mild conditions imposed on algorithm parameters.
Equilibrium problem Fixed point Nonexpansive mapping Variational inclusion
http://www.sciencedirect.com/science/article/B6VCT-5223Y1T-3/2/ce69018de492f37a5a413b3006ed4217
Yao, Yonghong
Cho, Yeol Je
Liou, Yeong-Cheng
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:301-3112011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:301-311
article
An optimization model for software component selection under multiple applications development
Component based software development (CBSD) is well acknowledged as a methodology which establishes reusability of software and reduce development cost effectively. While developing enterprise application using component based software engineering (CBSE) methods, software component selection plays a very important role in the process of component retrieval, adaptation and assembly. However, most of current researches focus on technical aspects from domain engineering and application engineering to improve reusability and system efficiency rather than application of optimization methods in CBSD management, especially application in component selection. Moreover, few existing researches have concerned about the situation where a software developer or enterprise develops multi-applications at the same time. By introducing the concept of reusability and a new formulation of compatibility matrix, an optimization model is proposed to solve component selection problem considering reusability and compatibility simultaneously. The model can be used to assist software developers in selecting software components when multi-applications are undertaken concurrently. Four experiments are conducted with the purpose to provide some insights in management perspective.
Component based software development Components selection Reusability Multi-applications development Optimization model Experimental analysis
http://www.sciencedirect.com/science/article/B6VCT-52307S7-1/2/7086e3811dd6092084e61de819546063
Tang, J.F.
Mu, L.F.
Kwong, C.K.
Luo, X.G.
oai:RePEc:eee:ejores:v:203:y:2010:i:1:p:156-1652011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:203:y:2010:i:1:p:156-165
article
Importance functions for restart simulation of general Jackson networks
RESTART is an accelerated simulation technique that allows the evaluation of extremely low probabilities. In this method a number of simulation retrials are performed when the process enters regions of the state space where the chance of occurrence of the rare event is higher. These regions are defined by means of a function of the system state called the importance function. Guidelines for obtaining suitable importance functions and formulas for the importance function of two-stage networks were provided in previous papers. In this paper, we obtain effective importance functions for RESTART simulation of Jackson networks where the rare set is defined as the number of customers in a particular ('target') node exceeding a predefined threshold. Although some rough approximations and assumptions are used to derive the formulas of the importance functions, they are good enough to estimate accurately very low probabilities for different network topologies within short computational time.
Simulation Queueing Rare event probabilities RESTART
http://www.sciencedirect.com/science/article/B6VCT-4WVK4VN-1/2/ff6e8b09ed1bd78780cd766f0da7c17e
Villén-Altamirano, José
oai:RePEc:eee:ejores:v:80:y:1995:i:3:p:451-2182011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:80:y:1995:i:3:p:451-218
article
Productivity analysis: Parametric and non-parametric applications
http://www.sciencedirect.com/science/article/B6VCT-4031TFX-1/2/a15bbb4643279a97556a46a6b5f3da27
Lewin, Arie Y.
Lovell, C. A. Knox
oai:RePEc:eee:ejores:v:195:y:2009:i:1:p:307-3182011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:195:y:2009:i:1:p:307-318
article
A decomposed metaheuristic approach for a real-world university timetabling problem
In this paper we present a decomposed metaheuristic approach to solve a real-world university course timetabling problem. Essential in this problem are the overlapping time slots and the irregular weekly timetables. A first stage in the approach reduces the number of subjects through the introduction of new structures that we call 'pillars'. The next stages involve a metaheuristic search that attempts to solve the constraints one by one, instead of trying to find a solution for all the constraints at once. Test results for a real-world instance are presented.
Metaheuristics Timetabling Tabu search Decomposed heuristic
http://www.sciencedirect.com/science/article/B6VCT-4RSJDTH-2/2/eb0a91dc2f410c635fbe7f4751d6cda0
De Causmaecker, Patrick
Demeester, Peter
Vanden Berghe, Greet
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:337-3442011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:337-344
article
Burn-in considering yield loss and reliability gain for integrated circuits
This paper presents burn-in effects on yield loss and reliability gain for a lifetime distribution developed from a negative binomial defect density distribution and a given defect size distribution, after assuming that the rate of defect growth is proportional to the power of the present defect size. While burn-in always results in yield loss, it creates reliability gain only if either defects grow fast or the field operation time is long. Otherwise, burn-in for a short time could result in reliability loss. The optimal burn-in time for maximizing reliability is finite if defects grow linearly in time and is infinite if defects grow nonlinearly in time. The optimal burn-in time for minimizing cost expressed in terms of both yield and reliability increases in the field operation time initially but becomes constant as the field operation time is long enough. It is numerically shown that increasing mean defect density or defect clustering increases the optimal burn-in time.
Reliability Defect growth Defect size distribution Negative binomial defect density
http://www.sciencedirect.com/science/article/B6VCT-521M6BM-1/2/04025244ba3f0b56249e5a29d46ff312
Kim, Kyungmee O.
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:345-3512011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:345-351
article
Gradient-based simulation optimization under probability constraints
We study optimization problems subject to possible fatal failures. The probability of failure should not exceed a given confidence level. The distribution of the failure event is assumed unknown, but it can be generated via simulation or observation of historical data. Gradient-based simulation-optimization methods pose the difficulty of the estimation of the gradient of the probability constraint under no knowledge of the distribution. In this work we provide two single-path estimators with bias: a convolution method and a finite difference, and we provide a full analysis of convergence of the Arrow-Hurwicz algorithm, which we use as our solver for optimization. Convergence results are used to tune the parameters of the numerical algorithms in order to achieve best convergence rates, and numerical results are included via an example of application in finance.
Probability constraints Stochastic gradient algorithm Stochastic approximation
http://www.sciencedirect.com/science/article/B6VCT-523M8CC-2/2/45472e2ce333340dd297a212774a9956
Andrieu, Laetitia
Cohen, Guy
Vázquez-Abad, Felisa J.
oai:RePEc:eee:ejores:v:201:y:2010:i:1:p:158-1702011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:201:y:2010:i:1:p:158-170
article
An economic production lot size model in an imperfect production system
The paper investigates an EPL (Economic Production Lotsize) model in an imperfect production system in which the production facility may shift from an 'in-control' state to an 'out-of-control' state at any random time. The basic assumption of the classical EPL model is that 100% of produced items are perfect quality. This assumption may not be valid for most of the production environments. More specifically, the paper extends the article of Khouja and Mehrez [Khouja, M., Mehrez, A., 1994. An economic production lot size model with imperfect quality and variable production rate. Journal of the Operational Research Society 45, 1405-1417]. Generally, the manufacturing process is 'in-control' state at the starting of the production and produced items are of conforming quality. In long-run process, the process shifts from the 'in-control' state to the 'out-of-control' state after certain time due to higher production rate and production-run-time.The proposed model is formulated assuming that a certain percent of total product is defective (imperfect), in 'out-of-control' state. This percentage also varies with production rate and production-run time. The defective items are restored in original quality by reworked at some costs to maintain the quality of products in a competitive market. The production cost per unit item is convex function of production rate. The total costs in this investment model include manufacturing cost, setup cost, holding cost and reworking cost of imperfect quality products. The associated profit maximization problem is illustrated by numerical examples and also its sensitivity analysis is carried out.
Imperfect production process Defective Inventory In-control-state Out-of-control state Production lotsize
http://www.sciencedirect.com/science/article/B6VCT-4VR2467-1/2/757308530af5487498d7da676ad1eb3a
Sana, Shib Sankar
oai:RePEc:eee:ejores:v:201:y:2010:i:3:p:873-8812011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:201:y:2010:i:3:p:873-881
article
Evaluation of credit risk based on firm performance
This paper investigates whether productive inefficiency measured as the distance from the industry's 'best practice' frontier is an important ex-ante predictor of business failure. We use samples of French textiles, wood and paper products, computers and R&D companies to obtain efficiency estimates for individual firms in each industry. These efficiency measures are derived from a directional technology distance function constructed empirically using non-parametric data envelopment analysis (DEA) methods. Estimating binary and ordered logit regression models we find that productive efficiency has significant explanatory power in predicting the likelihood of default over and above the effect of standard financial indicators.
G21 Credit risk Data envelopment analysis (DEA) Directional distance functions Bankruptcy prediction
http://www.sciencedirect.com/science/article/B6VCT-4VY78NS-7/2/cf36531ffdd1ecbe0a07a8639b3d2eb1
Psillaki, Maria
Tsolas, Ioannis E.
Margaritis, Dimitris
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:429-4312011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:429-431
article
Comment to "interactive fuzzy goal programming approach for bilevel programming problem" by S.R. Arora and R. Gupta
The fuzzy bilevel programming problem is solved in the paper [1] using an approach of fuzzy goal programming. Using a simple example we show that this will not lead to a satisfactory solution. Especially the fuzzy constraint that the upper level variable is near some desired one has no influence on the computed solution in the example. This constraint is used to model the hierarchy in the approach in [1]. At the end of the paper we suggest one straightforward possibility for modeling the fuzzy bilevel programming problem and converting it into a crisp substitute.
Hierarchical games Bilevel programming Fuzzy optimization problems
http://www.sciencedirect.com/science/article/B6VCT-526DWM4-2/2/c29746ba3d6a897572a724b911952585
Dempe, S.
oai:RePEc:eee:ejores:v:207:y:2010:i:2:p:1130-11392011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:207:y:2010:i:2:p:1130-1139
article
An integer programming dynamic farm-household model to evaluate the impact of agricultural policy reforms on farm investment behaviour
We develop a multi-objective farm-household dynamic integer programming model to simulate investment behaviour in different policy and price scenarios, with a particular focus on the decoupling of the Common Agricultural Policy (CAP). The model takes into account the characteristics of individual assets, including ageing and fixity through the explicit consideration of transaction costs. A case study application in the context of arable farming in Northern Italy is provided as an example. The results emphasise different patterns of reaction of different farm-household types over time, as an effect of the varying opportunity costs of resources and initial asset endowments. Overall, this application highlights the potentialities and limits of the methodology. In particular, the approach proved to be effective in providing a variety of results depending on the individual features of each farm-household, such as the differences between: (a) a 'no reaction' attitude; (b) an adaptation of farm activity and assets; and (c) a radical reaction pattern guided by high-income alternatives to farming. This highlights the potential of this tool as a generator of ideas and working hypotheses. We argue that, in view of the further developments of the CAP, the use of instruments able to account for multiple objectives, dynamics and investment choices will become even more relevant in the analysis of EU agricultural policy.
OR in agriculture Dynamic models Household models Multi-objective models Investment
http://www.sciencedirect.com/science/article/B6VCT-5033XTM-1/2/1cb45d943dadc8b1de58a6bceac72985
Viaggi, Davide
Raggi, Meri
Gomez y Paloma, Sergio
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:325-3362011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:325-336
article
Fuzzy goal programming for inventory management: A bacterial foraging approach
An efficient inventory planning approach in today's global trading regime is necessary not only for increasing the profit margin, but also to maintain system flexibility for achieving higher customer satisfaction. Such an approach should hence be comprised of a prudent inventory policy and clear satisfaction of stakeholder's goals. Relative significance given to various objectives in a supply chain network varies with product as well as time. In this paper, a model is proposed to fill this void for a single product inventory control of a supply chain consisting of three echelons. A generic modification proposed to the membership functions of the fuzzy goal-programming approach is used to mathematically map the aspiration levels of the decision maker. The bacterial foraging algorithm has been modified with enhancement of the algorithms' capability to map integer solution spaces and utilised to solve resulting fuzzy multi-objective function. An illustrative example comprehensively covers various decision scenarios and highlights the underlying managerial insights.
Supply chain management Fuzzy goal-programming Inventory management Bacterial foraging algorithm
http://www.sciencedirect.com/science/article/B6VCT-524FSCP-1/2/5ca3692c5e69ed8d4af023e8558ea6be
Deshpande, Paras
Shukla, Deepak
Tiwari, M.K.
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:293-3002011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:293-300
article
Coordinating a decentralized supply chain with customer returns and price-dependent stochastic demand using a buyback policy
We investigate a decentralized supply chain that consists of a manufacturer and a retailer where the retailer simultaneously determines the retail price and order quantity while experiencing customer returns and price dependent stochastic demand. We propose an agreement between the manufacturer and the retailer that includes two buyback prices, one for unsold inventory and a second for customer returns, and show that this type of easy-to-implement agreement can achieve perfect supply chain coordination and be a win-win for both manufacturer and retailer when a complementary profit-sharing agreement is included.
Supply chain management Coordination mechanism Buyback policies Pricing Inventory policies
http://www.sciencedirect.com/science/article/B6VCT-5211JFH-2/2/f38ab452769f9c02d3880902cabab75b
Chen, Jing
Bell, Peter C.
oai:RePEc:eee:ejores:v:209:y:2011:i:2:p:166-1752011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:209:y:2011:i:2:p:166-175
article
Portfolio rebalancing model using multiple criteria
In order to achieve greater flexibility in portfolio selection, transaction cost, short selling and higher moments should be considered, and actual transactions should be reflected. In this paper, five portfolio rebalancing models, with consideration of transaction cost and consisting of some or all criteria, including risk, return, short selling, skewness, and kurtosis, are compared to determine the important design criteria for a portfolio model. Two examples are used to perform simulated transactions, and the results indicate that the investment strategy of 'buy and hold' does not produce better returns for all the portfolios in the first example, and the models with higher moments or adopting short selling strategy perform better while rebalancing in the second example.
Portfolio selection Short selling Skewness Kurtosis Transaction cost
http://www.sciencedirect.com/science/article/B6VCT-51491G1-2/2/e67612e4cd8ff0a1660d396edaa2d14b
Yu, Jing-Rung
Lee, Wen-Yi
oai:RePEc:eee:ejores:v:208:y:2011:i:2:p:170-1762011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:208:y:2011:i:2:p:170-176
article
Estimation of production technology when the objective is to maximize return to the outlay
This paper deals with estimation of production technology where endogeneous choice of input and output variables is explicitly recognized. To address this endogeneity issue, we assume that producers maximize return to the outlay. We start from a flexible (translog) transformation function with a single output and multiple inputs and show how the first-order conditions of maximizing return to the outlay can be used to come up with an 'estimating equation' that does not suffer from the econometric endogeneity problem although the output and input variables are chosen endogenously. This is because the regressors in this estimating equation are in ratio forms which are uncorrelated with the error term under the assumption that producers maximize return to the outlay. The analysis is then extended to the multiple outputs and multiple inputs case with technical inefficiency. Although the estimating equations in both single and multiple output cases are neither production nor distance functions, they can be estimated in a straightforward manner using the standard stochastic frontier technique without worrying about endogeneity of the regressors. Thus, we provide a rationale for estimating the technology parameters consistently using an econometric model which requires data on only input and output quantities.
Distance function Transformation function Translog function Technical inefficiency
http://www.sciencedirect.com/science/article/B6VCT-51491G1-1/2/21064ac9724d8b0180fd4f1766aa0fc2
Kumbhakar, Subal C.
oai:RePEc:eee:ejores:v:202:y:2010:i:2:p:563-5732011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:202:y:2010:i:2:p:563-573
article
Efficiency and equity in private and public education: A nonparametric comparison
We present a nonparametric approach for (1) efficiency and (2) equity evaluation in education. Firstly, we use a nonparametric (Data Envelopment Analysis) model that is specially tailored to assess educational efficiency at the pupil level. The model accounts for the fact that typically minimal prior structure is available for the behavior (objectives and feasibility set) under evaluation. It allows for uncertainty in the data, while it corrects for exogenous 'environmental' characteristics that are specific to each pupil. Secondly, we propose two multidimensional stochastic dominance criteria as naturally complementary aggregation criteria for comparing the performance of different school types (private and public schools). While the first criterion only accounts for efficiency, the second criterion also takes equity into consideration. The model is applied for comparing private (but publicly funded) and public primary schools in Flanders. Our application finds that no school type robustly dominates another type when controlling for the school environment and taking equity into account. More generally, it demonstrates the usefulness of our nonparametric approach, which includes environmental and equity considerations, for obtaining 'fair' performance comparisons in the public sector context.
Data Envelopment Analysis Equity Efficiency Private versus public education Nonparametric analysis
http://www.sciencedirect.com/science/article/B6VCT-4WM0J9C-1/2/f730408535090b42c7d310feb74524a7
Cherchye, Laurens
De Witte, Kristof
Ooghe, Erwin
Nicaise, Ides
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:312-3242011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:312-324
article
Joint management of capacity and inventory in make-to-stock production systems with multi-class demand
We evaluate the benefits of coordinating capacity and inventory decisions in a make-to-stock production environment. We consider a firm that faces multi-class demand and has additional capacity options that are temporary and randomly available. We formulate the model as a Markov decision process (MDP) and prove that a solution to the optimal joint control problem exists. For several special cases we characterize the structure of the optimal policy. For the general case, however, we show that the optimal policy is state-dependent, and in many instances non-monotone and difficult to implement. Therefore, we consider three pragmatic heuristic policies and assess their performance. We show that the majority of the savings originate from the ability to dynamically adjust capacity, and that a simple heuristic that can adjust production capacity (based on workload fluctuation) but uses a static production/rationing policy can result in significant savings.
Inventory Dynamic programming Flexible capacity Joint control Multi-class demand
http://www.sciencedirect.com/science/article/B6VCT-523CDNV-1/2/f9a42780063f15f6279cfd5e48c0b0b0
Mayorga, Maria E.
Ahn, Hyun-Soo
oai:RePEc:eee:ejores:v:207:y:2010:i:3:p:1350-13572011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:207:y:2010:i:3:p:1350-1357
article
A simple model of deferred callability in defaultable debt
Banks and other financial institutions issue hybrid capital as part of their risk capital. Hybrid capital has no maturity, but, similarly to most corporate debt, includes an embedded issuer's call option. To obtain acceptance as risk capital, the first possible exercise date of the embedded call is contractually deferred by several years, generating a protection period. We value the call feature as a European option on perpetual defaultable debt. We do this by first modifying the underlying asset process to incorporate a time-dependent bankruptcy level before the expiration of the embedded option. We identify a call option on debt as a fixed number of put options on a modified asset, which is lognormally distributed, as opposed to the market value of debt. To include the possibility of default before the expiration of the option we apply barrier options results. The formulas are quite general and may be used for valuing both embedded and third-party options. All formulas are developed in the seminal and standard Black-Scholes-Merton model and, thus, standard analytical tools such as 'the greeks', are immediately available.
Callable perpetual debt Barrier options Hybrid capital
http://www.sciencedirect.com/science/article/B6VCT-50CVR12-1/2/ee5a15f3c9f168def2d467b5de95bdf6
Mjøs, Aksel
Persson, Svein-Arne
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:263-2762011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:263-276
article
New formulations of the Hop-Constrained Minimum Spanning Tree problem via Miller-Tucker-Zemlin constraints
Given an undirected network with positive edge costs and a natural number p, the Hop-Constrained Minimum Spanning Tree problem (HMST) is the problem of finding a spanning tree with minimum total cost such that each path starting from a specified root node has no more than p hops (edges). In this paper, we develop new formulations for HMST. The formulations are based on Miller-Tucker-Zemlin (MTZ) subtour elimination constraints, MTZ-based liftings in the literature offered for HMST, and a new set of topology-enforcing constraints. We also compare the proposed models with the MTZ-based models in the literature with respect to linear programming relaxation bounds and solution times. The results indicate that the new models give considerably better bounds and solution times than their counterparts in the literature and that the new set of constraints is competitive with liftings to MTZ constraints, some of which are based on well-known, strong liftings of Desrochers and Laporte (1991).
Graph theory Integer programming Spanning trees Hop constraints Miller-Tucker-Zemlin constraints
http://www.sciencedirect.com/science/article/B6VCT-523CDNV-2/2/a785d03d2f73b123d29525819d4e8461
Akgün, Ibrahim
Tansel, Barbaros Ç.
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:277-2862011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:277-286
article
Incorporating ergonomic risks into assembly line balancing
In manufacturing, control of ergonomic risks at manual workplaces is a necessity commanded by legislation, care for health of workers and economic considerations. Methods for estimating ergonomic risks of workplaces are integrated into production routines at most firms that use the assembly-type of production. Assembly line re-balancing, i.e., re-assignment of tasks to workers, is an effective and, in case that no additional workstations are required, inexpensive method to reduce ergonomic risks. In our article, we show that even though most ergonomic risk estimation methods involve nonlinear functions, they can be integrated into assembly line balancing techniques at low additional computational cost. Our computational experiments indicate that re-balancing often leads to a substantial mitigation of ergonomic risks.
Scheduling Combinatorial optimization Ergonomic risk assessment Assembly line balancing Simulated annealing
http://www.sciencedirect.com/science/article/B6VCT-523M8CC-5/2/4f3954723873f9892d26805b18be910c
Otto, Alena
Scholl, Armin
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:251-2622011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:251-262
article
Stackelberg equilibria in managerial delegation games
Managerial compensation packages do not only influence managers' behavior, but also have an impact on competing firms. In a managerial delegation game investigating the latter aspect, it is shown that the inherent prisoner's dilemma situation can be resolved (without changing the normally studied setup or timing). In the first stage, owners choose an incentive function for their managers, in the second stage they choose the weights assigned to that function besides profits and in the third stage managers play a Cournot game. Solving this continuous optimization problem with the implicit function theorem shows that choosing an incentive from the set of "multiplicative incentives", i.e. any generalized affine transformation of the product of both firms' quantities, which includes e.g. relative profit, ensures that the Stackelberg outcome is among the set of equilibrium outcomes. Furthermore, it is the unique outcome if the rival owner opts for one of the well-known incentives like sales, revenue or market share. The general approach used allows demonstrating that with no other linear incentive a Stackelberg outcome results and that incentives like profit-to-cost ratio should be avoided. Selecting a multiplicative incentive is a dominant strategy of the game.
Game theory Economics Continuous optimization Managerial incentives Strategic delegation
http://www.sciencedirect.com/science/article/B6VCT-526SP81-6/2/2dbb8c33c267fecae5abee37295cc2be
Berr, Fabian
oai:RePEc:eee:ejores:v:209:y:2011:i:3:p:219-2272011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:209:y:2011:i:3:p:219-227
article
A hybrid placement strategy for the three-dimensional strip packing problem
This paper presents a hybrid placement strategy for the three-dimensional strip packing problem which involves packing a set of cuboids ('boxes') into a three-dimensional bin (parallelepiped) of fixed width and height but unconstrained length (the 'container'). The goal is to pack all of the boxes into the container, minimising its resulting length. This problem has potential industry application in stock cutting (wood, polystyrene, etc. - minimising wastage) and also cargo loading, as well as other applications in areas such as multi-dimensional resource scheduling. In addition to the proposed strategy a number of test results on available literature benchmark problems are presented and analysed. The results of empirical testing of the algorithm show that it out-performs other methods from the literature, consistently in terms of speed and solution quality-producing 28 best known results from 35 test cases.
Cutting/packing Heuristics Metaheuristics
http://www.sciencedirect.com/science/article/B6VCT-5137F9D-2/2/a7a5150ed6131e7880c22e2f3e1ca176
Allen, S.D.
Burke, E.K.
Kendall, G.
oai:RePEc:eee:ejores:v:211:y:2011:i:1:p:139-1472011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:211:y:2011:i:1:p:139-147
article
Forecasting demand for single-period products: A case study in the apparel industry
The problem considered is that of forecasting demand for single-period products before the period starts. We study this problem for the case of a mail order apparel company that needs to order its products pre-season. The lack of historical demand data implies that other sources of data are needed. Advance order data can be obtained by allowing a selected group of customers to pre-order at a discount from a preview catalogue. Judgments can be obtained from purchase managers or other company experts. In this paper, we compare several existing and new forecasting methods for both sources of data. The methods are generic and can be used in any single-period problem in the apparel or fashion industries. Among the pre-order based methods, a novel 'top-flop' approach provides promising results. For a small group of products from the case company, expert judgment methods perform better than the methods based on advance demand information. The comparative results are obviously restricted to the specific case study, and additional testing is required to determine whether they are valid in general.
Demand forecasting Apparel Mail order
http://www.sciencedirect.com/science/article/B6VCT-51F7PPJ-1/2/fc22ebde98d0bc63ca8f533439ce209a
Mostard, Julien
Teunter, Ruud
de Koster, René
oai:RePEc:eee:ejores:v:200:y:2010:i:2:p:451-4642011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:200:y:2010:i:2:p:451-464
article
A production-inventory model in an imperfect production process
The paper develops a model to determine the optimal product reliability and production rate that achieves the biggest total integrated profit for an imperfect manufacturing process. The basic assumption of the classical Economic Manufacturing Quantity (EMQ) model is that all manufacturing items are of perfect quality. The assumption is not true in practice. Most of the production system produces perfect and imperfect quality items. In some cases the imperfect quality (non conforming) items are reworked at a cost to restore its quality to the original one. Rework cost may be reduced by improvements in product reliability (i.e., decreasing in product reliability parameter). Lower value of product reliability parameter results in increase development cost of production and also smaller quantity of nonconforming products. The unit production cost is a function of product reliability parameter and production rate. As a result, higher development cost increases unit production cost. The problem of optimal planning work and rework processes belongs to the broad field of production-inventory model which deals with all kinds of reuse processes in supply chains. These processes aim to recover defective product items in such a way that they meet the quality level of 'good item'. The benefits from imperfect quality items are: regaining the material and value added on defective items and improving the environment protection. In this point of view, a model is introduced here to guide a firm/industry in addressing variable product reliability factor, variable unit production cost and dynamic production rate for time-varying demand. The paper provides an optimal control formulation of the problem and develops necessary and sufficient conditions for optimality of the dynamic variables. In this purpose, the Euler-Lagrange method is used to obtain optimal solutions for product reliability parameter and dynamic production rate. Finally, numerical examples are given to illustrate the proposed model.
Time-varying demand Imperfect production Inventory Product reliability
http://www.sciencedirect.com/science/article/B6VCT-4VJBTPT-1/2/21ea64d4ab330a33cd453b7f81f85d80
Sana, Shib Sankar
oai:RePEc:eee:ejores:v:204:y:2010:i:3:p:391-4012011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:204:y:2010:i:3:p:391-401
article
Solving a class of constrained 'black-box' inverse variational inequalities
It is well known that a general network economic equilibrium problem can be formulated as a variational inequality (VI) and solving the VI will result in a description of network equilibrium state. In this paper, however, we discuss a class of normative control problem that requires the network equilibrium state to be in a linearly constrained set. We formulate the problem as an inverse variational inequality (IVI) because the variables and the mappings in the IVI are in the opposite positions of a classical VI. In addition, the mappings in IVI usually do not have any explicit forms and only implicit information on the functional value is available through exogenous evaluation or direct observation. For such class of network equilibrium control problem, we present a linearly constrained implicit IVI formulation and a solution method based on proximal point algorithm (PPA) that only needs functional values for given variables in the solution process.
Black-box Inverse variational inequality Nonlinear programming Proximal point algorithm
http://www.sciencedirect.com/science/article/B6VCT-4WSRF20-1/2/7f0c091f3d053aa09558c75df270b812
He, Bingsheng
He, Xiao-Zheng
Liu, Henry X.
oai:RePEc:eee:ejores:v:200:y:2010:i:1:p:297-3042011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:200:y:2010:i:1:p:297-304
article
A semi-oriented radial measure for measuring the efficiency of decision making units with negative data, using DEA
Data Envelopment Analysis (DEA) is a nonparametric method for measuring the efficiency of a set of decision making units such as firms or public sector agencies, first introduced into the operational research and management science literature by Charnes, Cooper, and Rhodes (CCR) [Charnes, A., Cooper, W.W., Rhodes, E., 1978. Measuring the efficiency of decision making units. European Journal of Operational Research 2, 429-444]. The original DEA models were applicable only to technologies characterized by positive inputs/outputs. In subsequent literature there have been various approaches to enable DEA to deal with negative data. In this paper, we propose a semi-oriented radial measure, which permits the presence of variables which can take both negative and positive values. The model is applied to data on a notional effluent processing system to compare the results with those yielded by two alternative methods for dealing with negative data in DEA: The modified slacks-based model suggested by Sharp et al. [Sharp, J.A., Liu, W.B., Meng, W., 2006. A modified slacks-based measure model for data envelopment analysis with 'natural' negative outputs and inputs. Journal of Operational Research Society 57 (11) 1-6] and the range directional model developed by Portela et al. [Portela, M.C.A.S., Thanassoulis, E., Simpson, G., 2004. A directional distance approach to deal with negative data in DEA: An application to bank branches. Journal of Operational Research Society 55 (10) 1111-1121]. A further example explores the advantages of using the new model.
Data Envelopment Analysis Negative data in DEA Translation-invariant DEA Slack-based model Range directional measure Semi-oriented radial measure
http://www.sciencedirect.com/science/article/B6VCT-4VBMNG0-2/2/bf5da8032cc770410987350765774c26
Emrouznejad, Ali
Anouze, Abdel Latef
Thanassoulis, Emmanuel
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:411-4162011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:411-416
article
Decomposing profit inefficiency in DEA through the weighted additive model
An issue that has received little attention in the Data Envelopment Analysis literature is the decomposition of profit inefficiency by means of measures that account all sources of technical inefficiency. In this paper we introduce a new way to measure and decompose profit inefficiency through weighted additive models. All our results are derived from a new Fenchel-Mahler inequality using duality theory.
Data Envelopment Analysis Profit inefficiency Weighted additive model Fenchel-Mahler inequality
http://www.sciencedirect.com/science/article/B6VCT-523M8CC-4/2/f17714a26876864a1bb9fb1a2d54bc02
Cooper, W.W.
Pastor, Jesus T.
Aparicio, Juan
Borras, Fernando
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:417-4282011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:417-428
article
Robust optimization and portfolio selection: The cost of robustness
Robust optimization is a tractable alternative to stochastic programming particularly suited for problems in which parameter values are unknown, variable and their distributions are uncertain. We evaluate the cost of robustness for the robust counterpart to the maximum return portfolio optimization problem. The uncertainty of asset returns is modelled by polyhedral uncertainty sets as opposed to the earlier proposed ellipsoidal sets. We derive the robust model from a min-regret perspective and examine the properties of robust models with respect to portfolio composition. We investigate the effect of different definitions of the bounds on the uncertainty sets and show that robust models yield well diversified portfolios, in terms of the number of assets and asset weights.
Uncertainty modelling Robust optimization Portfolio selection
http://www.sciencedirect.com/science/article/B6VCT-526SP81-1/2/e25256d85aed3fa73c532ecba317bf9b
Gregory, Christine
Darby-Dowman, Ken
Mitra, Gautam
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:361-3732011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:361-373
article
Robust multi-market newsvendor models with interval demand data
We present a robust model for determining the optimal order quantity and market selection for short-life-cycle products in a single period, newsvendor setting. Due to limited information about demand distribution in particular for short-life-cycle products, stochastic modeling approaches may not be suitable. We propose the minimax regret multi-market newsvendor model, where the demands are only known to be bounded within some given interval. In the basic version of the problem, a linear time solution method is developed. For the capacitated case, we establish some structural results to reduce the problem size, and then propose an approximation solution algorithm based on integer programming. Finally, we compare the performance of the proposed minimax regret model against the typical average-case and worst-case models. Our test results demonstrate that the proposed minimax regret model outperformed the average-case and worst-case models in terms of risk-related criteria and mean profit, respectively.
Risk analysis Newsvendor problem Minimax regret Uncertainty modeling
http://www.sciencedirect.com/science/article/B6VCT-524WF4J-1/2/2b5451ee8de1206f38de0a90df667eea
Lin, Jun
Ng, Tsan Sheng
oai:RePEc:eee:ejores:v:204:y:2010:i:2:p:237-2442011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:204:y:2010:i:2:p:237-244
article
Discretized formulations for capacitated location problems with modular distribution costs
In this paper we study a discretization reformulation technique in the context of a facility location problem with modular link costs. We present a so-called 'traditional' model and a straightforward discretized model with a general objective function whose variable coefficients are computed by solving a simple knapsack problem. We show that the linear programming relaxation of the discretized model dominates the linear programming relaxation of the original model. The discretized model suggests quite intuitive valid inequalities that considerably improve the linear programming relaxation of the original model. Computational results based on randomly generated data show that in the context of problems with modular costs, the proposed discretized models perform significantly better than the 'traditional' models. An important outcome of our research is the result, whose proof is also presented in this paper, that a restricted version of the discretized model gives an extended description of the convex hull of the integer solutions of a subproblem that usually arises in network design problems with modular costs.
Capacitated facility location Modular link costs Extended reformulations
http://www.sciencedirect.com/science/article/B6VCT-4XM6K93-3/2/67b052191c604d073c63be3bd1da26ae
Correia, Isabel
Gouveia, Luís
Saldanha-da-Gama, Francisco
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:223-2342011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:223-234
article
OR in healthcare: A European perspective
The European Working Group "Operational Research Applied to Health Services" (ORAHS) is one of the domain specific EURO Working Groups organized by EURO - the European Association of Operational Research Societies. In this paper we report on the development of ORAHS as a platform for OR in health, and analyse the papers presented at meetings over the 35Â years of its existence. We propose a two-way framework for analysis, where one dimension is the nine stages of the product life cycle: identifying consumer requirements, designing a new service to meet these requirements, forecasting demand for such a service, securing resources for it, allocating these resources, developing Programs & Plans to use these resources for delivering the service, establishing criteria for service delivery, managing the performance of the service, and finally, evaluating its performance. The other dimension is a three-level classification into broad application areas referring to processes at different levels in healthcare: Patients & Providers, Units & Hospitals, and Regional & National. We use this framework to carry out a quantitative analysis of all the papers presented during the meetings of ORAHS since its inception in 1975. We then describe developments over this period in applying OR approaches and techniques to healthcare, and present an overview of the main application areas and challenges.
OR in health services Applications of OR Review
http://www.sciencedirect.com/science/article/B6VCT-51B1WNK-3/2/b228a7469da439780ea35b2295c8ae04
Brailsford, Sally
Vissers, Jan
oai:RePEc:eee:ejores:v:190:y:2008:i:1:p:52-672011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:190:y:2008:i:1:p:52-67
article
Solution of real-world postman problems
The paper presents the results of a study performed by the Deutsche post endowed chair of optimization of distribution networks in collaboration with Deutsche Post World Net with the aim of improving the planning of letter mail delivery. Modelling and solution methods for real-world postman problems are presented which extend one of the most general postman problems studied in the literature, the windy rural postman problem, with regard to several aspects. The discussed extensions include turn and street crossing restrictions, cluster constraints, the option to have alternative service modes (including 'zigzag deliveries'), and the use of public transport to reach the postal district. The solution method is based on a transformation to the asymmetric TSP and uses non-standard neighbourhood search techniques. Extensive computational experiments show that the solution method clearly and consistently outperforms standard TSP heuristics on real-world instances.
http://www.sciencedirect.com/science/article/B6VCT-4NXXM9V-5/1/4633232aeaac9b4e0ce99ad83f673bde
Irnich, Stefan
oai:RePEc:eee:ejores:v:193:y:2009:i:2:p:484-4912011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:193:y:2009:i:2:p:484-491
article
The outflow ranking method for weighted directed graphs
A ranking method assigns to every weighted directed graph a (weak) ordering of the nodes. In this paper we axiomatize the ranking method that ranks the nodes according to their outflow using four independent axioms. Besides the well-known axioms of anonymity and positive responsiveness we introduce outflow monotonicity - meaning that in pairwise comparison between two nodes, a node is not doing worse in case its own outflow does not decrease and the other node's outflow does not increase - and order preservation - meaning that adding two weighted digraphs such that the pairwise ranking between two nodes is the same in both weighted digraphs, then this is also their pairwise ranking in the 'sum' weighted digraph. The outflow ranking method generalizes the ranking by outdegree for directed graphs, and therefore also generalizes the ranking by Copeland score for tournaments.
Decision analysis Weighted directed graph Ranking method Outflow Axiomatization
http://www.sciencedirect.com/science/article/B6VCT-4R8MDNW-3/2/a51b8a1bba5d5f6f970a521fa610fb1b
van den Brink, René
Gilles, Robert P.
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:235-2412011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:235-241
article
Optimality conditions under relaxed quasiconvexity assumptions using star and adjusted subdifferentials
A set-constrained optimization problem and a mathematical programming problem are considered. We assume that the sublevel sets of the involving functions are convex only at the point under question and hence these functions are not assumed quasiconvex. Using the two star subdifferentials and the adjusted subdifferential, we establish optimality conditions for usual minima and strict minima. Our results contain and improve some recent ones in the literature. Examples are provided to explain the advantages of each of our results.
Optimality conditions Convex sublevel sets Normal cones Star subdifferentials Adjusted subdifferentials
http://www.sciencedirect.com/science/article/B6VCT-523M8CC-1/2/a97b2dccc0396e1190c985f8499fcc02
Khanh, Phan Quoc
Quyen, Ho Thuc
Yao, Jen-Chih
oai:RePEc:eee:ejores:v:207:y:2010:i:1:p:391-4002011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:207:y:2010:i:1:p:391-400
article
Callable risky perpetual debt with protection period
Issuances in the USD 260 Bn global market of perpetual risky debt are often motivated by capital requirements for financial institutions. We analyze callable risky perpetual debt emphasizing an initial protection ('grace') period before the debt may be called. The total market value of debt including the call option is expressed as a portfolio of perpetual debt and barrier options with a time dependent barrier. We also analyze how an issuer's optimal bankruptcy decision is affected by the existence of the call option by using closed-form approximations. The model quantifies the increased coupon and the decreased initial bankruptcy level caused by the embedded option. Examples indicate that our closed form model produces reasonably precise coupon rates compared to numerical solutions. The credit-spread produced by our model is in a realistic order of magnitude compared to market data.
Callable perpetual debt Embedded options Barrier options Optimal bankruptcy
http://www.sciencedirect.com/science/article/B6VCT-4YX7KDD-2/2/9ff5a25e9afdabb9525b556269185b90
Mjøs, Aksel
Persson, Svein-Arne
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:352-3602011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:352-360
article
On the distribution of the number stranded in bulk-arrival, bulk-service queues of the M/G/1 form
Bulk-arrival queues with single servers that provide bulk service are widespread in the real world, e.g., elevators in buildings, people-movers in amusement parks, air-cargo delivery planes, and automated guided vehicles. Much of the literature on this topic focusses on the development of the theory for waiting time and number in such queues. We develop the theory for the number stranded, i.e., the number of customers left behind after each service, in queues of the M/G/1 form, where there is single server, the arrival process is Poisson, the service is of a bulk nature, and the service time is a random variable. For the homogenous Poisson case, in our model the service time can have any given distribution. For the non-homogenous Poisson arrivals, due to a technicality, we assume that the service time is a discrete random variable. Our analysis is not only useful for performance analysis of bulk queues but also in designing server capacity when the aim is to reduce the frequency of stranding. Past attempts in the literature to study this problem have been hindered by the use of Laplace transforms, which pose severe numerical difficulties. Our approach is based on using a discrete-time Markov chain, which bypasses the need for Laplace transforms and is numerically tractable. We perform an extensive numerical analysis of our models to demonstrate their usefulness. To the best of our knowledge, this is the first attempt in the literature to study this problem in a comprehensive manner providing numerical solutions.
Queueing Bulk queues Downside risk
http://www.sciencedirect.com/science/article/B6VCT-5259C4S-1/2/c8c3039f93419d11b80341f31cb04104
Kahraman, Aykut
Gosavi, Abhijit
oai:RePEc:eee:ejores:v:198:y:2009:i:1:p:223-2312011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:1:p:223-231
article
An extended queueing control model for facilities with front room and back room operations and mixed-skilled workers
Three related problems arising in retail facilities with front room and back room operations, and cross-trained workers, are considered. In the first problem, the goal is to determine an optimal policy for switching workers between the two rooms. In the second and third problems, the goal is to determine the minimum number of workers that should be hired by the facility such that a satisfactory switching policy exists. We analyze two questions arising from previous work on these problems. Firstly, we demonstrate that the previously proposed policy definition is sub-optimal and cannot represent a set of solutions that are reasonable in practice, and propose an alternative definition. Secondly, we examine the problem of finding the optimal combination of cross-trained and specialized workers under a complete set of assumptions regarding worker costs. This analysis shows that the structure of the optimal solution depends on the policy definition that is employed. Moreover, under some assumptions the cost of the 'optimal' solution with the original policy definition will be greater than the cost of the optimal solution with the new one.
Queue control Cross-trained workers Front room and back room operations Queueing
http://www.sciencedirect.com/science/article/B6VCT-4TB77B8-1/2/2b581073bd008974f183b1b6fb52dd8e
Terekhov, Daria
Christopher Beck, J.
oai:RePEc:eee:ejores:v:200:y:2010:i:3:p:755-7632011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:200:y:2010:i:3:p:755-763
article
Using a TSP heuristic for routing order pickers in warehouses
In this paper, we deal with the sequencing and routing problem of order pickers in conventional multi-parallel-aisle warehouse systems. For this NP-hard Steiner travelling salesman problem (TSP), exact algorithms only exist for warehouses with at most three cross aisles, while for other warehouse types literature provides a selection of dedicated construction heuristics. We evaluate to what extent reformulating and solving the problem as a classical TSP leads to performance improvements compared to existing dedicated heuristics. We report average savings in route distance of up to 47% when using the LKH (Lin-Kernighan-Helsgaun) TSP heuristic. Additionally, we examine if combining problem-specific solution concepts from dedicated heuristics with high-quality local search features could be useful. Lastly, we verify whether the sophistication of 'state-of-the-art' local search heuristics is necessary for routing order pickers in warehouses, or whether a subset of features suffices to generate high-quality solutions.
Routing Order picking Warehousing Logistics
http://www.sciencedirect.com/science/article/B6VCT-4VJ06GW-2/2/2291d4cf942da01a29fe81068546a135
Theys, Christophe
Bräysy, Olli
Dullaert, Wout
Raa, Birger
oai:RePEc:eee:ejores:v:207:y:2010:i:3:p:1573-15862011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:207:y:2010:i:3:p:1573-1586
article
COOPER-framework: A unified process for non-parametric projects
Practitioners assess performance of entities in increasingly large and complicated datasets. If non-parametric models, such as Data Envelopment Analysis, were ever considered as simple push-button technologies, this is impossible when many variables are available or when data have to be compiled from several sources. This paper introduces by the 'COOPER-framework' a comprehensive model for carrying out non-parametric projects. The framework consists of six interrelated phases: Concepts and objectives, On structuring data, Operational models, Performance comparison model, Evaluation, and Result and deployment. Each of the phases describes some necessary steps a researcher should examine for a well defined and repeatable analysis. The COOPER-framework provides for the novice analyst guidance, structure and advice for a sound non-parametric analysis. The more experienced analyst benefits from a check list such that important issues are not forgotten. In addition, by the use of a standardized framework non-parametric assessments will be more reliable, more repeatable, more manageable, faster and less costly.
DEA Non-parametric efficiency analysis Unified process COOPER-framework
http://www.sciencedirect.com/science/article/B6VCT-50R22YG-3/2/d1e9d0a5bbca8f3953d64fbd872e11fb
Emrouznejad, Ali
De Witte, Kristof
oai:RePEc:eee:ejores:v:191:y:2008:i:3:p:786-8022011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:191:y:2008:i:3:p:786-802
article
Solving circle packing problems by global optimization: Numerical results and industrial applications
A (general) circle packing is an optimized arrangement of N arbitrary sized circles inside a container (e.g., a rectangle or a circle) such that no two circles overlap. In this paper, we present several circle packing problems, review their industrial applications, and some exact and heuristic strategies for their solution. We also present illustrative numerical results using 'generic' global optimization software packages. Our work highlights the relevance of global optimization in solving circle packing problems, and points towards the necessary advancements in both theory and numerical practice.
http://www.sciencedirect.com/science/article/B6VCT-4NKXWJ9-4/1/52ba380e75e7b5d038e9326c02f5f1fe
Castillo, Ignacio
Kampas, Frank J.
Pintér, János D.
oai:RePEc:eee:ejores:v:198:y:2009:i:1:p:341-3502011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:1:p:341-350
article
An integrated performance evaluation of financial holding companies in Taiwan
There has been a worldwide trend for financial institutions to become larger in scale and more diversified in scope, with Taiwan being no exception. Fourteen financial holding companies (FHCs) have each begun to function as a management umbrella in Taiwan by investing in different types of financial services such as banking, insurance, and securities. This paper focuses on this local financing issue from an integrated methodological perspective by model innovations proposed in several earlier studies. For example, the efficiency of profitability and marketability are combined to evaluate the FHCs' performance. To conduct a valid and reliable evaluation process while applying the FHC's case in Taiwan, we integrate the slacks-based measure (SBM) and slacks-based measure of super efficiency (super-SBM) models in order to directly handle the slacks and identify the best performers. A new scheme that deals with the negative output data in the SBM/super-SBM is also introduced. Inter-temporal efficiency change, which is decomposed into 'catch-up' and 'frontier-shift' effects, is analyzed by means of the SBM-based Malmquist index. A decision-making matrix is also presented to help the FHCs' managerial authorities position themselves in the industry. The above techniques show with a high degree of consistency that large-sized FHCs perform better than small-sized ones.
FHCs Data envelopment analysis Efficiency Slacks Slacks-based measure Super efficiency Malmquist index Negative output data
http://www.sciencedirect.com/science/article/B6VCT-4TF2J2P-3/2/c014a4444f360e8b4e9390bfc21ff8ae
Lo, Shih-Fang
Lu, Wen-Min
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:386-3972011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:386-397
article
Time-cost trade-off analysis of project networks in fuzzy environments
This paper proposes a novel approach for time-cost trade-off analysis of a project network in fuzzy environments. Different from the results of previous studies, in this paper the membership function of the fuzzy minimum total crash cost is constructed based on Zadeh's extension principle and fuzzy solutions are provided. A pair of two-level mathematical programs parameterized by possibility level [alpha] is formulated to calculate the lower and upper bounds of the fuzzy minimum total crash cost at [alpha]. By enumerating different values of [alpha], the membership function of the fuzzy minimum total crash cost is constructed, and the corresponding optimal activity time for each activity is also obtained at the same time. An example of time-cost trade-off problem with several fuzzy parameters is solved successfully to demonstrate the validity of the proposed approach. Since the minimum total crash cost is expressed by a membership function rather than by a crisp value, the fuzziness of parameters is conserved completely, and more information is provided for time-cost trade-off analysis in project management. The proposed approach also can be applied to time-cost trade-off problems with other characteristics.
Fuzzy sets Project management Time-cost trade-off Crash Parametric programming
http://www.sciencedirect.com/science/article/B6VCT-524FSCP-3/2/1d92ab92c0acdb0ae7f397e8e2d4acf7
Chen, Shih-Pin
Tsai, Ming-Jiun
oai:RePEc:eee:ejores:v:201:y:2010:i:1:p:1-102011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:201:y:2010:i:1:p:1-10
article
Exploiting special structure in semidefinite programming: A survey of theory and applications
Semidefinite programming (SDP) may be seen as a generalization of linear programming (LP). In particular, one may extend interior point algorithms for LP to SDP, but it has proven much more difficult to exploit structure in the SDP data during computation. We survey three types of special structures in SDP data: 1. A common 'chordal' sparsity pattern of all the data matrices. This structure arises in applications in graph theory, and may also be used to deal with more general sparsity patterns in a heuristic way. 2. Low rank of all the data matrices. This structure is common in SDP relaxations of combinatorial optimization problems, and SDP approximations of polynomial optimization problems. 3. The situation where the data matrices are invariant under the action of a permutation group, or, more generally, where the data matrices belong to a low dimensional matrix algebra. Such problems arise in truss topology optimization, particle physics, coding theory, computational geometry, and graph theory. We will give an overview of existing techniques to exploit these structures in the data. Most of the paper will be devoted to the third situation, since it has received the least attention in the literature so far.
Semidefinite programming Chordal sparsity Algebraic symmetry
http://www.sciencedirect.com/science/article/B6VCT-4VG5H6X-2/2/e345a1146d3f8d9e5ccf02e533489b14
Klerk, Etienne de
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:130-1382011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:130-138
article
Goodwill, inventory penalty, and adaptive supply chain management
Information visibility is generally useful for decision makers distributed across supply chains. Availability of information on inventory levels, price, lead times, demand, etc. can help reduce uncertainties as well as alleviate problems associated with bullwhip effect. A majority of extant literature in this area assume a static supply chain network configuration. While this was sufficient a few decades ago, advances in e-commerce and the ease with which order processing can be performed over the Internet necessitates appropriate dynamic (re)configuration of supply chains over time. Each node in the supply chain is modeled as an actor who makes independent decisions based on information gathered from the next level upstream. A knowledge-based framework is used for dynamic supply chain configuration and to consider the effects of inventory constraints and 'goodwill,' as well as their effects on the performance dynamics of supply chains. Preliminary results indicate that neither static nor dynamic configurations are consistently dominant. Scenarios where static configurations perform better than the modeled system are identified.
Learning Supply chain management Inventory Goodwill
http://www.sciencedirect.com/science/article/B6VCT-4TY459J-2/2/1aa8c0dad6b3b4e5fddfdbe2ce9a9e13
Emerson, Denise
Zhou, Wei
Piramuthu, Selwyn
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:398-4102011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:398-410
article
The effects of sensitization and habituation in durable goods markets
We develop a model to study the impact of changes in price sensitivity on the firm as it introduces multiple generations of a durable product where unit costs are a convex function of quality. We incorporate the psychological processes of sensitization and habituation into a model of discretionary purchasing of replacement products motivated by past experience. When price sensitivity decreases with each purchase (sensitization), the myopic firm offers a higher quality product at a much higher price with each generation. When price sensitivity increases with each purchase (habituation), the myopic firm engages in price skimming. When sensitization is followed by habituation, the myopic firm eventually provides higher quality than the market is willing to pay for, leading to a steep drop-off in sales and profits. The actions of the forward-looking firm depend on the discount rate. A firm with a low discount rate builds its customer base before offering a higher quality and higher priced product. In contrast, a firm with a high discount rate quickly increases price and quality following the same path to falling profits of the myopic firm. These results provide insight into the firm and consumer behaviors underlying the phenomenon of "performance oversupply" identified in the innovation literature.
Marketing Durable goods Buyer behavior Pricing Product policy
http://www.sciencedirect.com/science/article/B6VCT-5223Y1T-2/2/f2b521c9f3faf3ea4b844a3ce2332329
Liberali, Guilherme
Gruca, Thomas S.
Nique, Walter M.
oai:RePEc:eee:ejores:v:196:y:2009:i:3:p:1214-12222011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:196:y:2009:i:3:p:1214-1222
article
Equilibria of two-sided matching games with common preferences
Problems of matching have long been studied in the operations research literature (assignment problem, secretary problem, stable marriage problem). All of these consider a centralized mechanism whereby a single decision maker chooses a complete matching which optimizes some criterion. This paper analyzes a more realistic scenario in which members of the two groups (buyers-sellers, employers-workers, males-females) randomly meet each other in pairs (interviews, dates) over time and form couples if there is mutual agreement to do so. We assume members of each group have common preferences over members of the other group. Generalizing an earlier model of Alpern and Reyniers [Alpern, S., Reyniers, D.J., 2005. Strategic mating with common preferences. J. Theor. Biol. 237, 337-354], we assume that one group (called males) is r times larger than the other, r[greater-or-equal, slanted]1. Thus all females, but only 1/r of the males, end up matched. Unmatched males have negative utility -c. We analyze equilibria of this matching game, depending on the parameters r and c. In a region of (r,c) space with multiple equilibria, we compare these, and analyze their 'efficiency' in several respects. This analysis should prove useful for designers of matching mechanisms who have some control over the sex ratio (e.g. by capping numbers of males at a 'singles event'or by having 'ladies free' nights) or the nonmating cost c (e.g. tax benefits to married couples).
OR in biology Game theory Search theory
http://www.sciencedirect.com/science/article/B6VCT-4SKK20V-1/2/454776f8fa0bee83868e8ca584237ca9
Alpern, Steve
Katrantzi, Ioanna
oai:RePEc:eee:ejores:v:201:y:2010:i:1:p:329-3352011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:201:y:2010:i:1:p:329-335
article
A note on 'Efficient scheduling of periodic information monitoring requests'
A recently published paper by Zeng et al. [Zeng, D.D., Dror, M., Chen, H., 2006. Efficient scheduling of periodic information monitoring requests. European Journal of Operational Research 173, 583-599] considers the non-preemptive scheduling of periodic server information requests for mission-critical monitoring applications such as policing and homeland security. In their paper, it was claimed that the decision version of the considered Periodic Monitoring (PM) problem was NP-Complete, and several greedy heuristics were developed to 'efficiently' solve the problem. The standard argument of polynomial-time solution verification was employed in their complexity proof. However, the present note points out that the PM problem is actually -Complete, and verification of a PM solution is coNP-Complete, in the strong sense. A consequence of these results is that the greedy heuristics proposed by Zeng et al. are all strongly coNP-Hard, invalidating the authors' claims of efficiency; since their algorithms are implemented on-line in a mission-critical application, this clearly needs to be taken into account. The final contributions of the present note are the description of an efficient algorithm for the underlying peak server load problem, and showing that equivalence classes in request start times can be efficiently detected and pruned prior to searching. These former elements - if incorporated into the original heuristics - can potentially improve stability and efficiency by large orders of magnitude.
Non-preemptive scheduling Greedy heuristics Periodic queries Complexity
http://www.sciencedirect.com/science/article/B6VCT-4VWHW1N-2/2/bea1ecb8dfe85a2068132164c2a50aab
Short, Michael
oai:RePEc:eee:ejores:v:198:y:2009:i:1:p:232-2402011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:1:p:232-240
article
Optimality conditions in preference-based spanning tree problems
Spanning tree problems defined in a preference-based environment are addressed. In this approach, optimality conditions for the minimum-weight spanning tree problem (MST) are generalized for use with other, more general preference orders. The main goal of this paper is to determine which properties of the preference relations are sufficient to assure that the set of 'most-preferred' trees is the set of spanning trees verifying the optimality conditions. Finally, algorithms for the construction of the set of spanning trees fulfilling the optimality conditions are designed, improving the methods in previous papers.
Multiple criteria analysis Preference modelling Multiobjective spanning tree problems
http://www.sciencedirect.com/science/article/B6VCT-4T5JHW5-2/2/17bc7c574194e6b24adf2db2148f7302
Alonso, Sergio
Domínguez-Ríos, Miguel Ángel
Colebrook, Marcos
Sedeo-Noda, Antonio
oai:RePEc:eee:ejores:v:197:y:2009:i:3:p:1075-10832011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:197:y:2009:i:3:p:1075-1083
article
Use of the equivalent attribute technique in multi-criteria planning of local energy systems
This paper discusses how the equivalent attribute technique (EAT) can be used to improve the comprehensibility of a multi-attribute utility theory study. When using EAT, 'vague' expected total utility values are converted into equivalent values for one of the attributes being considered, often an economic attribute. Two models are considered: a simplified linear model, and a more advanced non-linear model that includes the DM's strength-of-preference and risk attitude. EAT is particularly useful in distinguishing between alternatives with similar utility values. When the difference between utility values is larger, the choice among the alternatives should be clear, and EAT therefore becomes less useful. The technique can still be used, although extra care is needed when choosing the equivalent attribute. A local energy-planning problem is used as a case study to illustrate and exemplify the EAT approach.
Multiple criteria analysis OR in energy Equivalent attribute technique Local energy-planning Multi-attribute utility theory
http://www.sciencedirect.com/science/article/B6VCT-4S21TKY-7/2/19115d3b36a9e507fb97fbf25b152997
Løken, Espen
Botterud, Audun
Holen, Arne T.
oai:RePEc:eee:ejores:v:202:y:2010:i:1:p:182-1952011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:202:y:2010:i:1:p:182-195
article
Applying relation algebra and RelView to measures in a social network
We present an application of relation algebra to measure agents' 'strength' in a social network with influence between agents. In particular, we deal with power, success, and influence of an agent as measured by the generalized Hoede-Bakker index and its modifications, and by the influence indices. We also apply relation algebra to determine followers of a coalition and the kernel of an influence function. This leads to specifications, which can be executed with the help of the BDD-based tool RelViewÂ after a simple translation into the tool's programming language. As an example we consider the present Dutch Parliament.
RelView Relation algebra Social network Hoede-Bakker index Influence index
http://www.sciencedirect.com/science/article/B6VCT-4WBK79X-1/2/6f6dc8585f177d8672ac3c4a9152aa5f
Berghammer, Rudolf
Rusinowska, Agnieszka
de Swart, Harrie
oai:RePEc:eee:ejores:v:204:y:2010:i:2:p:206-2172011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:204:y:2010:i:2:p:206-217
article
Evolutionary, constructive and hybrid procedures for the bi-objective set packing problem
The bi-objective set packing problem is a multi-objective combinatorial optimization problem similar to the well-known set covering/partitioning problems. To our knowledge and surprise, this problem has not yet been studied whereas several applications have been reported. Unfortunately, solving the problem exactly in a reasonable time using a generic solver is only possible for small instances. We designed three alternative procedures for approximating solutions to this problem. The first is derived from the original 'Strength Pareto Evolutionary Algorithm', which is a population-based metaheuristic. The second is an adaptation of the 'Greedy Randomized Adaptative Search Procedure', which is a constructive metaheuristic. As underlined in the overview of the literature summarized here, almost all the recent, effective procedures designed for approximating optimal solutions to multi-objective combinatorial optimization problems are based on a blend of techniques, called hybrid metaheuristics. Thus, the third alternative, which is the primary subject of this paper, is an original hybridization of the previous two metaheuristics. The algorithmic aspects, which differ from the original definition of these metaheuristics, are described, so that our results can be reproduced. The performance of our procedures is reported and the computational results for 120 numerical instances are discussed.
Multiple objective programming Metaheuristics Set packing problem Hybrid method
http://www.sciencedirect.com/science/article/B6VCT-4XJ17NG-1/2/0d0ce22738b61d2d3477dfc40560deee
Delorme, Xavier
Gandibleux, Xavier
Degoutin, Fabien
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:287-2922011-04-14RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:287-292
article
Parallel machines scheduling with machine maintenance for minsum criteria
This paper considers a parallel-machine scheduling problem with machine maintenance. There are unavailable periods on each of the first k machines, and the remaining mÂ -Â k machines are always available, where 1Â [less-than-or-equals, slant]Â kÂ [less-than-or-equals, slant]Â m is an integer. The objective is to minimize the total completion time of all jobs. We show the classical SPT algorithm has a worst-case ratio of at most when kÂ <Â m. If there is exactly one unavailable period on each of the first k machines, and the unavailable periods do not overlap, the worst-case ratio of SPT is at most , and no polynomial time approximation algorithm with worst-case ratio less than can exist when kÂ =Â m unless PÂ =Â NP.
Scheduling Machine maintenance Approximation algorithm Worst-case analysis
http://www.sciencedirect.com/science/article/B6VCT-524WF4J-3/2/4b4a3f1fb7354acef9dc68fecc6c78ad
Tan, Zhiyi
Chen, Yong
Zhang, An
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:260-2642010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:260-264
article
On the product line selection problem under attraction choice models of consumer behavior
Product line design (PLD) involves important decisions at the interface of operations and marketing that are very costly to implement and change, and, simultaneously, determinant for market success. To evaluate the financial performance of a product line, a number of mathematical programming approaches have been proposed. Problem formulations are typically mixed or pure integer non-linear optimization models that are intractable for exact solution - in particular when empirically supported consumer choice models are incorporated. In this note, we present an exact approach for determining a profit-maximizing product line with continuous prices when consumers choose among available products according to a general and widely applied attraction choice model including the MNL, the BTL, the MCI, and approximately the first choice model. In particular, we show how to efficiently exploit the structural properties resulting from attraction models when consumer behavior is (a) modelled at the aggregate level or (b) disaggregated into customer segments in such a way that each segment can be offered a customized price - a strategy that firms more and more engage in, recognizing it to be not only very profitable but also implementable in the era of e-business. Under these assumptions, we can transform the standard MINLP formulation of the PLD problem into a more convenient convex MIP that can be solved globally with current solvers even for large instances with ten-thousands of products in reasonable time. Therefore our work contributes by accommodating a new trend increasingly encountered in practice and by providing an efficient exact approach to profit-driven PLD for real-world applications.
Pricing Product line design
http://www.sciencedirect.com/science/article/B6VCT-4Y8G5VG-1/2/d18f57e6a4c5e2dd4574776749ff7cca
Schön, Cornelia
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:528-5392010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:528-539
article
Scheduling two agents with controllable processing times
We consider several two-agent scheduling problems with controllable job processing times, where agents A and B have to share either a single machine or two identical machines in parallel while processing their jobs. The processing times of the jobs of agent A are compressible at additional cost. The objective function for agent B is always the same, namely a regular function fmax. Several different objective functions are considered for agent A, including the total completion time plus compression cost, the maximum tardiness plus compression cost, the maximum lateness plus compression cost and the total compression cost subject to deadline constraints (the imprecise computation model). All problems are to minimize the objective function of agent A subject to a given upper bound on the objective function of agent B. These problems have various applications in computer systems as well as in operations management. We provide NP-hardness proofs for the more general problems and polynomial-time algorithms for several special cases of the problems.
Agent scheduling Controllable processing times Availability constraints Imprecise computation Total completion time Maximum tardiness Maximum lateness
http://www.sciencedirect.com/science/article/B6VCT-4Y95RKK-1/2/334da8d80a73fe1b4fa6856fa1a4e2eb
Wan, Guohua
Vakati, Sudheer R.
Leung, Joseph Y.-T.
Pinedo, Michael
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:417-4252010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:417-425
article
Interactive evolutionary multi-objective optimization for quasi-concave preference functions
We present a new hybrid approach to interactive evolutionary multi-objective optimization that uses a partial preference order to act as the fitness function in a customized genetic algorithm. We periodically send solutions to the decision maker (DM) for her evaluation and use the resulting preference information to form preference cones consisting of inferior solutions. The cones allow us to implicitly rank solutions that the DM has not considered. This technique avoids assuming an exact form for the preference function, but does assume that the preference function is quasi-concave. This paper describes the genetic algorithm and demonstrates its performance on the multi-objective knapsack problem.
Interactive optimization Multi-objective optimization Evolutionary optimization Knapsack problem
http://www.sciencedirect.com/science/article/B6VCT-4YHT7SR-1/2/d32645e7fcfa5ba7688c3079fa5bc64a
Fowler, John W.
Gel, Esma S.
Köksalan, Murat M.
Korhonen, Pekka
Marquis, Jon L.
Wallenius, Jyrki
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:118-1222010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:118-122
article
Analysis of a two-phase queueing system with a fixed-size batch policy
We consider a single-server, two-phase queueing system with a fixed-size batch policy. Customers arrive at the system according to a Poisson process and receive batch service in the first-phase followed by individual services in the second-phase. The batch service in the first-phase is applied for a fixed number (k) of customers. If the number of customers waiting for the first-phase service is less than k when the server completes individual services, the system stays idle until the queue length reaches k. We derive the steady state distribution for the system's queue length. We also show that the stochastic decomposition property can be applied to our model. Finally, we illustrate the process of finding the optimal batch size that minimizes the long-run average cost under a linear cost structure.
Two-phase queue Fixed batch size Regeneration cycle Stochastic decomposition
http://www.sciencedirect.com/science/article/B6VCT-4YC1K3P-3/2/025d7b50bd0f4fa4022574325cbc0d72
Park, Hyun-Min
Kim, Tae-Sung
Chae, Kyung C.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:604-6142010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:604-614
article
Sales and operations planning in systems with order configuration uncertainty
This paper addresses the problem of aligning demand and supply in configure-to-order systems. Using stochastic programming methods, this study demonstrates the value of accounting for the uncertainty associated with how orders are configured. We also demonstrate the value of component supply flexibility in the presence of order configuration uncertainty. We present two stochastic models: an explosion problem model and an implosion problem model. These models are positioned sequentially within a popular business process called sales and operations planning. Both models are formulated as two-stage stochastic programs with recourse and are solved using the sample average approximation method. Computational analyses were performed using data obtained from IBM System and Technology Group. The problem sets used in our analysis are created from actual industry data and our results show that significant improvements in revenue and serviceability can be achieved by appropriately accounting for the uncertainty associated with order configurations.
Sales and operations planning Configure-to-order Stochastic programming
http://www.sciencedirect.com/science/article/B6VCT-4Y7P6VC-1/2/36984acf675356d5d0e784ef803d91c6
Chen-Ritzo, Ching-Hua
Ervolina, Tom
Harrison, Terry P.
Gupta, Barun
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:571-5832010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:571-583
article
Travel time models for automated warehouses with aisle transferring storage and retrieval machine
This paper presents analytical travel time models for the computation of travel time for automated warehouses with the aisle transferring S/R machine (in continuation multi-aisle AS/RS). These models consider the operating characteristics of the storage and retrieval machine such as acceleration and deceleration and the maximum velocity. Assuming uniform distributed storage rack locations and pick aisles and using the probability theory, the expressions of the cumulative distribution functions with which the mean travel time is calculated, have been determined. The computational models enable the calculation of the mean travel time for the single and dual command cycles, from which the performance of multi-aisle AS/RS can be evaluated. A simulation model of multi-aisle AS/RS has been developed to compare the performances of the proposed analytical travel time models. The analyses show that regarding all examined types of multi-aisle AS/RS, the results of proposed analytical travel time models correlate with the results of simulation models of multi-aisle AS/RS.
Logistics Automated storage and retrieval systems Multi-aisle system Analytical modeling Simulation
http://www.sciencedirect.com/science/article/B6VCT-4Y70C5Y-5/2/ff268d0339e13fafed310267a38f7680
Lerher, Tone
Potrc, Iztok
Sraml, Matjaz
Tollazzi, Tomaz
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:634-6412010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:634-641
article
Robust network design in telecommunications under polytope demand uncertainty
We consider a model for robust network design in telecommunications, in which we minimize the cost of the maximum mismatch between supply and demand. In the present study, the demand is uncertain and takes its values in a polytope defined by constraints. This problem is hardly tractable, so we limit ourselves to computing lower bounds (by a column-generation mechanism) and upper bounds (using an algorithm due to Falk and Soland for maximizing a separable convex function over a polytope). The experimental gap obtained turns out to be large, and this seems to be mainly due to poor upper bounds. Two possible solutions are suggested for further research aimed at improving them: dc optimization (to minimize the difference of two convex functions) and AARC modeling (affinely adjustable robust counterpart).
65K05 90C25 90C27 Telecommunication network design Polyhedral uncertainty Robust optimization Min-max-min problems
http://www.sciencedirect.com/science/article/B6VCT-4YM7VX4-1/2/7d933e03aff22a7db2b95d631f185dd1
Lemaréchal, Claude
Ouorou, Adam
Petrou, Georgios
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:361-3732010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:361-373
article
Nash game model for optimizing market strategies, configuration of platform products in a Vendor Managed Inventory (VMI) supply chain for a product family
This paper discusses how a manufacturer and its retailers interact with each other to optimize their product marketing strategies, platform product configuration and inventory policies in a VMI (Vendor Managed Inventory) supply chain. The manufacturer procures raw materials from multiple suppliers to produce a family of products sold to multiple retailers. Multiple types of products are substitutable each other to end customers. The manufacturer makes its decision on raw materials' procurement, platform product configuration, product replenishment policies to retailers with VMI, price discount rate, and advertising investment to maximize its profit. Retailers in turn consider the optimal local advertising investments and retail prices to maximize their profits. This problem is modeled as a dual simultaneous non-cooperative game (as a dual Nash game) model with two sub-games. One is between the retailers serving in competing retail markets and the other is between the manufacturer and the retailers. This paper combines analytical, iterative and GA (genetic algorithm) methods to develop a game solution algorithm to find the Nash equilibrium. A numerical example is conducted to test the proposed model and algorithm, and gain managerial implications.
Supply chain management Vendor Managed Inventory Nash game model
http://www.sciencedirect.com/science/article/B6VCT-4YJ4N9T-3/2/2e50c115b5d1e121d768c4e2f15117b6
Yu, Yugang
Huang, George Q.
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:271-2802010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:271-280
article
Satisfactory graph partition, variants, and generalizations
The Satisfactory Partition problem asks for deciding if a given graph has a partition of its vertex set into two nonempty parts such that each vertex has at least as many neighbors in its part as in the other part. This problem was introduced by Gerber and Kobler [M. Gerber, D. Kobler, Algorithmic approach to the satisfactory graph partitioning problem, European Journal of Operational Research 125 (2000) 283-291] and studied further by other authors. In this paper we first review some applications and related problems. Then, we survey structural, complexity, and approximation results obtained for Satisfactory Partition and for some of its variants and generalizations. A list of open questions concludes this survey.
Combinatorial optimization Complexity theory Vertex partition Degree constraints Approximation algorithm
http://www.sciencedirect.com/science/article/B6VCT-4XKHD9G-5/2/e6faac296ff768430c5f94b22a345d97
Bazgan, Cristina
Tuza, Zsolt
Vanderpooten, Daniel
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:479-4872010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:479-487
article
Determining sources of relative inefficiency in heterogeneous samples: Methodology using Cluster Analysis, DEA and Neural Networks
Data Envelopment Analysis (DEA) is a powerful data analytic tool that is widely used by researchers and practitioners alike to assess relative performance of Decision Making Units (DMU). Commonly, the difference in the scores of relative performance of DMUs in the sample is considered to reflect their differences in the efficiency of conversion of inputs into outputs. In the presence of scale heterogeneity, however, the source of the difference in scores becomes less clear, for it is also possible that the difference in scores is caused by heterogeneity of the levels of inputs and outputs of DMUs in the sample. By augmenting DEA with Cluster Analysis (CA) and Neural Networks (NN), we propose a five-step methodology allowing an investigator to determine whether the difference in the scores of scale heterogeneous DMUs is due to the heterogeneity of the levels of inputs and outputs, or whether it is caused by their efficiency of conversion of inputs into outputs. An illustrative example demonstrates the application of the proposed methodology in action.
Relative efficiency Data Envelopment Analysis Neural Networks Cluster Analysis Heterogeneous sample
http://www.sciencedirect.com/science/article/B6VCT-4YDKJW6-2/2/7cc0c33d1b7fdcaed1230e9dc7be1667
Samoilenko, Sergey
Osei-Bryson, Kweku-Muata
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:595-6032010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:595-603
article
Modeling customer impatience in a newsboy problem with time-sensitive shortages
Customers across all stages of the supply chain often respond negatively to inventory shortages. One approach to modeling customer responses to shortages in the inventory control literature is time-dependent partial backlogging. Partial backlogging refers to the case in which a customer will backorder shortages with some probability, or will otherwise solicit the supplier's competitors to fulfill outstanding shortages. If the backorder rate (i.e., the probability that a customer elects to backorder shortages) is assumed to be dependent on the supplier's backorder replenishment lead-time, then shortages are said to be represented as time-dependent partial backlogging. This paper explores various backorder rate functions in a single period stochastic inventory problem in an effort to characterize a diversity of customer responses to shortages. We use concepts from utility theory to formally classify customers in terms of their willingness to wait for the supplier to replenish shortages. Under mild assumptions, we verify the existence of a unique optimal solution that corresponds to each customer type. Sensitivity analysis experiments are conducted in order to compare the optimal actions associated with each customer type under a variety of conditions. Additionally, we introduce the notion of expected value of customer patience information (EVCPI), and then conduct additional sensitivity analyses to determine the most and least opportune conditions for distinguishing between customer behaviors.
Inventory control Customer responsiveness Time-dependent partial backlogging Demand uncertainty Utility theory
http://www.sciencedirect.com/science/article/B6VCT-4Y7P4KW-3/2/59fa17dbb8b8cd03e1b0d26edeeb58be
Lee, Hwansik
Lodree Jr., Emmett J.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:269-2702010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:269-270
article
Comment on "A new clustering approach using data envelopment analysis"
In a recent paper Po, Guh and Yang [Po, R.-W., Guh, Y.-Y., Yang, M.-S., 2009. A new clustering approach using data envelopment analysis. European Journal of Operational Research 199, 276-284] propose a new algorithm for forming clusters from the results of a DEA analysis. In this comment it is explained that the algorithm only generates information that is readily available from the usual DEA results.
Data envelopment analysis Cluster analysis DEA-based clustering
http://www.sciencedirect.com/science/article/B6VCT-4YDT3XM-3/2/c0e7a05456fa70179bf5482aca9fc5b1
Krüger, Jens J.
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:540-5462010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:540-546
article
Scheduling problems with two competing agents to minimize minmax and minsum earliness measures
A relatively new class of scheduling problems consists of multiple agents who compete on the use of a common processor. We focus in this paper on a two-agent setting. Each of the agents has a set of jobs to be processed on the same processor, and each of the agents wants to minimize a measure which depends on the completion times of its own jobs. The goal is to schedule the jobs such that the combined schedule performs well with respect to the measures of both agents. We consider measures of minmax and minsum earliness. Specifically, we focus on minimizing maximum earliness cost or total (weighted) earliness cost of one agent, subject to an upper bound on the maximum earliness cost of the other agent. We introduce a polynomial-time solution for the minmax problem, and prove NP-hardness for the weighted minsum case. The unweighted minsum problem is shown to have a polynomial-time solution.
Multi-agent scheduling Single machine Earliness
http://www.sciencedirect.com/science/article/B6VCT-4YJT5DP-1/2/b43f8cae826b948120139e6b990363d7
Mor, Baruch
Mosheiov, Gur
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:586-6002010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:586-600
article
Technology choice under several uncertainty sources
We analyze a model of irreversible investment with two sources of uncertainty. A risk-neutral decision maker has the choice between two mutually exclusive projects under input price and output price uncertainty. We propose a complete study of the shape of the rational investment region and we prove that it is never optimal to invest when the alternative investments generate the same payoff independently of its size. A key feature of this bidimensional degree of uncertainty is thus that the payoff generated by each project is not a sufficient statistic to make a rational investment. In this context, our analysis provides a new motive for waiting to invest: the benefits associated with the dominance of one project over the other. As an illustration, we apply our methodology to power generation under uncertainty.
Investment under uncertainty Technology choice Optimal stopping Real options
http://www.sciencedirect.com/science/article/B6VCT-4YK2F3B-2/2/e581898e360500ed49296aaaeb4b7114
Bobtcheff, Catherine
Villeneuve, Stéphane
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:470-4782010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:470-478
article
Simultaneous classification and feature selection via convex quadratic programming with application to HIV-associated neurocognitive disorder assessment
Support vector machines (SVMs), that utilize a mixture of the L1-norm and the L2-norm penalties, are capable of performing simultaneous classification and selection of highly correlated features. These SVMs, typically set up as convex programming problems, are re-formulated here as simple convex quadratic minimization problems over non-negativity constraints, giving rise to a new formulation - the pq-SVM method. Solutions to our re-formulation are obtained efficiently by an extremely simple algorithm. Computational results on a range of publicly available datasets indicate that these methods allow greater classification accuracy in addition to selecting groups of highly correlated features. These methods were also compared on a new dataset assessing HIV-associated neurocognitive disorder in a group of 97 HIV-infected individuals.
Quadratic optimization Support vector machines Classification Feature selection Nonnegativity constraints HIV Neurocognitive disorder
http://www.sciencedirect.com/science/article/B6VCT-4YM7FH3-4/2/a3b9972e52fd64b1f7b5439ecdb15184
Dunbar, Michelle
Murray, John M.
Cysique, Lucette A.
Brew, Bruce J.
Jeyakumar, Vaithilingam
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:231-2382010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:231-238
article
DEA-based hypothesis tests for comparing two groups of decision making units
In this paper, we develop five statistical tests to compare the efficiencies of different groups of DMUs. We consider a data generating process (DGP) that models the deviation of the output from the best practice frontier as the sum of two components, a one-sided inefficiency term and a two-sided random noise term. We use simulation to evaluate the performance of the five tests against the Banker tests (Banker, 1993) that were designed for DGPs containing a single one-sided error term. It is found that while the Banker tests are very effective when efficiency dominates noise, the tests developed in this paper perform better than the Banker tests when noise levels are significant.
Data envelopment analysis Hypothesis tests Data generating process Efficiency comparison
http://www.sciencedirect.com/science/article/B6VCT-4Y70C5Y-4/2/506d77b8162bd753a5712663a8d79db2
Banker, Rajiv D.
Zheng, Zhiqiang (Eric)
Natarajan, Ram
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:239-2472010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:239-247
article
Considering endogeneity for optimal catalog allocation in direct marketing
The majority of catalog allocation models using historical data ignore endogeneity of past catalog decisions. We investigate two alternative approaches which either impose a relationship between the number of catalogs allocated to a customer and customer-specific coefficients of the sales response function or use instrumental variables. Heterogeneity across customers is modeled by cluster effects following a nonparametric distribution derived from a Dirichlet process prior. Models are estimated by Markov chain Monte Carlo simulation methods and evaluated by cross-validation predictive densities. Models which consider endogeneity imply much lower effects for sending a higher number of catalogs. These models also lead to optimal allocations which differ strongly from optimal allocations obtained for models which ignore endogeneity. Higher values of both posterior model probabilities and model average profits suggest to allocate catalogs based on the instrumental variables approach.
(D) Marketing Direct marketing Endogeneity Hierarchical Bayesian modeling
http://www.sciencedirect.com/science/article/B6VCT-4Y7P6VC-2/2/a4f98ea8681e989b1e3df0092825c0e8
Hruschka, Harald
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:601-6082010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:601-608
article
The group consensus based evidential reasoning approach for multiple attributive group decision analysis
Many multiple attribute decision analysis problems include both quantitative and qualitative attributes with various kinds of uncertainties such as ignorance, fuzziness, interval data, and interval belief degrees. An evidential reasoning (ER) approach developed in the 1990s and in recent years can be used to model these problems. In this paper, the ER approach is extended to group consensus (GC) situations for multiple attributive group decision analysis problems. In order to construct and check the GC, a compatibility measure between two belief structures is developed first. Considering two experts' utilities, the compatibility between their assessments is naturally constructed using the compatibility measure. Based on the compatibility between two experts' assessments, the GC at a specific level that may be the attribute level, the alternative level, or the global level, can be constructed and reached after the group analysis and discussion within specified times. Under the condition of GC, we conduct a study on the forming of group assessments for alternatives, the achievement of the aggregated utilities of assessment grades, and the properties and procedure of the extended ER approach. An engineering project management software selection problem is solved by the extended ER approach to demonstrate its detailed implementation process, and its validity and applicability.
Decision analysis Multiple attributive group decision analysis Evidential reasoning approach Group consensus Compatibility measure
http://www.sciencedirect.com/science/article/B6VCT-4YJCKSY-7/2/dc02d3d5f653c0c3b51294a9fbf8684f
Fu, Chao
Yang, Shan-Lin
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:642-6522010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:642-652
article
Scheduling elective surgery under uncertainty and downstream capacity constraints
The objective of this study is to generate an optimal surgery schedule of elective surgery patients with uncertain surgery operations, which includes uncertainty in surgery durations and the availability of downstream resources such as surgical intensive care unit (SICU) over multi-periods. The stochastic optimization is adapted and the sample average approximation (SAA) method is proposed for obtaining an optimal surgery schedule with respect to minimizing the total cost of patient costs and overtime costs. A computational experiment is presented to evaluate the performance of the proposed method.
Surgery scheduling problem Downstream resource constraint Stochastic programming
http://www.sciencedirect.com/science/article/B6VCT-4YN5PFF-1/2/000b2dbaf0b68517b2482ea99b101389
Min, Daiki
Yih, Yuehwern
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:676-6852010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:676-685
article
Learning intransitive reciprocal relations with kernel methods
In different fields like decision making, psychology, game theory and biology, it has been observed that paired-comparison data like preference relations defined by humans and animals can be intransitive. Intransitive relations cannot be modeled with existing machine learning methods like ranking models, because these models exhibit strong transitivity properties. More specifically, in a stochastic context, where often the reciprocity property characterizes probabilistic relations such as choice probabilities, it has been formally shown that ranking models always satisfy the well-known strong stochastic transitivity property. Given this limitation of ranking models, we present a new kernel function that together with the regularized least-squares algorithm is capable of inferring intransitive reciprocal relations in problems where transitivity violations cannot be considered as noise. In this approach it is the kernel function that defines the transition from learning transitive to learning intransitive relations, and the Kronecker-product is introduced for representing the latter type of relations. In addition, we empirically demonstrate on two benchmark problems, one in game theory and one in theoretical biology, that our algorithm outperforms methods not capable of learning intransitive reciprocal relations.
Transitivity Reciprocal relations Utility functions Kernel methods Preference learning Decision theory Game theory
http://www.sciencedirect.com/science/article/B6VCT-4YM7FH3-1/2/6d4a54642346a904d3ab1bcc6087b3cf
Pahikkala, Tapio
Waegeman, Willem
Tsivtsivadze, Evgeni
Salakoski, Tapio
De Baets, Bernard
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:638-6492010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:638-649
article
A queueing system with n-phases of service and (n-1)-types of retrial customers
A queueing system with a single server providing n-phases of service in succession is considered. Every customer receives service in all phases. Arriving customers join a single ordinary queue, waiting to start the service procedure. When a customer completes his service in the ith phase he decides either to proceed to the next phase or to join the Ki retrial box (i=1,2,...,n-1), from where he repeats the demand for the (i+1)th phase of service after a random amount of time and independently to the other customers in the system. Every customer can join during his service procedure a number of retrial boxes before departs from the system. When at the moment that a customer, either departs from the system or joins a retrial box and so releases the server, there are no other customers waiting in the ordinary queue, then the server departs for a single vacation of an arbitrarily distributed length. The arrival process is assumed to be Poisson and all service times are arbitrarily distributed. For such a system, the mean number of customers in the ordinary queue and in each retrial box separately are obtained, and used to investigate numerically system performance.
Poisson arrivals n-Phase service Retrial queues General services Single vacation
http://www.sciencedirect.com/science/article/B6VCT-4Y7MM1T-1/2/716d1e3f4a16a1ee57754a873bef07c7
Langaris, Christos
Dimitriou, Ioannis
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:609-6132010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:609-613
article
No-arbitrage conditions, scenario trees, and multi-asset financial optimization
Many numerical optimization methods use scenario trees as a discrete approximation for the true (multi-dimensional) probability distributions of the problem's random variables. Realistic specifications in financial optimization models can lead to tree sizes that quickly become computationally intractable. In this paper we focus on the two main approaches proposed in the literature to deal with this problem: scenario reduction and state aggregation. We first state necessary conditions for the node structure of a tree to rule out arbitrage. However, currently available scenario reduction algorithms do not take these conditions explicitly into account. State aggregation excludes arbitrage opportunities by relying on the risk-neutral measure. This is, however, only appropriate for pricing purposes but not for optimization. Both limitations are illustrated by numerical examples. We conclude that neither of these methods is suitable to solve financial optimization models in asset-liability or portfolio management.
Financial optimization Uncertainty modeling Scenario trees Sparse trees
http://www.sciencedirect.com/science/article/B6VCT-4YM7K8V-1/2/c09cb8311ab5ae7a8452c8041d01b185
Geyer, Alois
Hanke, Michael
Weissensteiner, Alex
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:623-6332010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:623-633
article
Throughput optimization in robotic cells with input and output machine buffers: A comparative study of two key models
We consider the problem of scheduling operations in a robotic cell processing a single part type. Each machine in the cell has a one-unit input buffer and a one-unit output buffer. The machines and buffers are served by one single gripper robot. The domain considered is free-pickup cells with additive inter-machine travel time. The processing constraints specify the cell to be a flow shop. The objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes throughput. Bufferless robotic cells have been studied extensively in the literature. However, the few studies of robotic cells with output buffers at each machine have shown that the throughput can be improved by such a configuration. We show that there is no throughput advantage in providing machine input buffers in addition to output buffers. The equivalence in throughput between the two models has significant practical implications, since the cost of providing additional buffers at each machine is substantial.
Robotic cells Input/output machine buffers Cyclic scheduling
http://www.sciencedirect.com/science/article/B6VCT-4YJ4N9T-1/2/19b63954d47c8721730f50f9c60c69d2
Drobouchevitch, Inna G.
Neil Geismar, H.
Sriskandarajah, Chelliah
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:522-5272010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:522-527
article
Neighborhood search approaches to non-coplanar beam orientation optimization for total marrow irradiation using IMRT
We consider the beam orientation optimization (BOO) problem for total marrow irradiation (TMI) treatment planning using intensity modulated radiation therapy (IMRT). Currently, IMRT is not widely used in TMI treatment delivery; furthermore, the effect of using non-coplanar beam orientations is not known. We propose and implement several variations of a single neighborhood search algorithm that solves the BOO problem effectively when gantry angles and couch translations are considered. Our work shows that the BOO problem for TMI cases can be solved in a clinically acceptable amount of time and leads to treatment plans that are more effective than the conventional approach to TMI.
Total marrow irradiation Total body irradiation Intensity modulated radiation therapy Radiotherapy optimization Local search Beam orientation optimization
http://www.sciencedirect.com/science/article/B6VCT-4YDKJW6-3/2/6900278b1235f06dd81a7eec389abff4
Misic, V.V.
Aleman, D.M.
Sharpe, M.B.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:552-5562010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:552-556
article
Nash equilibria in competitive project scheduling
We consider the problem of scheduling activities of a project by a firm that competes with another firm that has to perform the same project. The profit that a firm gets from each activity depends on whether the firm finishes the activity before or after its competitor. It is required to find a Nash equilibrium solution or show that no such solutions exist. We present a structural characterization of Nash equilibrium solutions, and a low order polynomial algorithm for the problem.
Project scheduling Nash equilibrium Polynomial algorithm
http://www.sciencedirect.com/science/article/B6VCT-4YCS00V-3/2/05cfb70d7a265802616bb1678ab4f32f
Averbakh, Igor
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:456-4692010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:456-469
article
Globally flexible functional forms: The neural distance function
The output distance function is a key concept in economics. However, its empirical estimation often violates properties dictated by neoclassical production theory. In this paper, we introduce the neural distance function (NDF) which constitutes a global approximation to any arbitrary production technology with multiple outputs given by a neural network (NN) specification. The NDF imposes all theoretical properties such as monotonicity, curvature and homogeneity, for all economically admissible values of outputs and inputs. Fitted to a large data set for all US commercial banks (1989-2000), the NDF explains a very high proportion of the variance of output while keeping the number of parameters to a minimum and satisfying the relevant theoretical properties. All measures such as total factor productivity (TFP) and technical efficiency (TE) are computed routinely. Next, the NDF is compared with the Translog popular specification and is found to provide very satisfactory results as it possesses the properties thought as desirable in neoclassical production theory in a way not matched by its competing specification.
Output distance function Translog Technical efficiency ANN LIML
http://www.sciencedirect.com/science/article/B6VCT-4YCWNKT-2/2/49197d965d2ff2a6ac45832d8cb969e9
Michaelides, Panayotis G.
Vouldis, Angelos T.
Tsionas, Efthymios G.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:155-1672010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:155-167
article
A hybrid scatter search heuristic for personalized crew rostering in the airline industry
The crew scheduling problem in the airline industry is extensively investigated in the operations research literature since efficient crew employment can drastically reduce operational costs of airline companies. Given the flight schedule of an airline company, crew scheduling is the process of assigning all necessary crew members in such a way that the airline is able to operate all its flights and constructing a roster line for each employee minimizing the corresponding overall cost for personnel. In this paper, we present a scatter search algorithm for the airline crew rostering problem. The objective is to assign a personalized roster to each crew member minimizing the overall operational costs while ensuring the social quality of the schedule. We combine different complementary meta-heuristic crew scheduling combination and improvement principles. Detailed computational experiments in a real-life problem environment are presented investigating all characteristics of the procedure. Moreover, we compare the proposed scatter search algorithm with optimal solutions obtained by an exact branch-and-price procedure and a steepest descent variable neighbourhood search.
Airline crew rostering Meta-heuristics Scatter search
http://www.sciencedirect.com/science/article/B6VCT-4Y9CF8M-1/2/e00dc48925bd0a580684f9b70bf4ce40
Maenhout, Broos
Vanhoucke, Mario
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:281-2882010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:281-288
article
New lower bounds for bin packing problems with conflicts
The bin packing problem with conflicts (BPC) consists of minimizing the number of bins used to pack a set of items, where some items cannot be packed together in the same bin due to compatibility restrictions. The concepts of dual-feasible functions (DFF) and data-dependent dual-feasible functions (DDFF) have been used in the literature to improve the resolution of several cutting and packing problems. In this paper, we propose a general framework for deriving new DDFF as well as a new concept of generalized data-dependent dual-feasible functions (GDDFF), a conflict generalization of DDFF. The GDDFF take into account the structure of the conflict graph using the techniques of graph triangulation and tree-decomposition. Then we show how these techniques can be used in order to improve the existing lower bounds.
Bin packing with conflicts Knapsack problem Lower bounds Chordal graphs Tree-decomposition Dual-feasible functions
http://www.sciencedirect.com/science/article/B6VCT-4YR8B1B-1/2/7ca10285f44af5a03e443b6fe735bf05
Khanafer, Ali
Clautiaux, François
Talbi, El-Ghazali
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:221-2302010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:221-230
article
Random yield supply chain with a yield dependent secondary market
This paper considers a simple supply chain with one supplier and one retailer where the supplier's production is subject to random yield and the retailer faces uncertain demand. There exists a secondary market for acquiring or disposing products by the supplier. We study both the centralized and decentralized systems. In the decentralized system, a no risk sharing contract and a risk sharing minimum commitment contract are analyzed. The supply chain with the risk sharing contract is further analyzed with a constant secondary market price and a yield dependent secondary market price. We present both the supplier's and the retailer's optimal strategies and provide insights for managers when making decisions under random yield risk and demand uncertainty. We find that the secondary market generally has a positive impact on supply chain performance and the actual effect of random yield risk on the supply chain performance depends on cost parameters and supply chain contract settings. Under certain conditions, reducing yield randomness may weaken the double marginalization effect and improve the chain performance. From the numerical study, we also show that there exists an optimal commitment level for the supply chain.
Production Supply chain management Random yield Risk sharing Commitment contract
http://www.sciencedirect.com/science/article/B6VCT-4YFTM1F-1/2/aadfcffe61fe57dc22bc989c388473d1
He, Yuanjie
Zhang, Jiang
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:569-5782010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:569-578
article
A turning restriction design problem in urban road networks
Turning restriction is one of the commonest traffic management techniques and an effective low cost traffic improvement strategy in urban road networks. However, the literature has not paid much attention to the turning restriction design problem (TRDP), which aims to determine a set of intersections where turning restrictions should be implemented. In this paper, a bi-level programming model is proposed to formulate the TRDP. The upper level problem is to minimize the total travel cost from the viewpoint of traffic managers, and the lower level problem is to depict travelers' route choice behavior based on stochastic user equilibrium (SUE) theory. We propose a branch and bound method (BBM), based on the sensitivity analysis algorithm (SAA), to find the optimal turning restriction strategy. A branch strategy and a bound strategy are applied to accelerate the solution process of the TRDP. The computational experiments give promising results, showing that the optimal turning restriction strategy can obviously reduce system congestion and are robust to the variations of both the dispersion parameter of the SUE problem and the level of demand.
Turning restriction design problem Bi-level programming Stochastic user equilibrium Sensitivity analysis Branch and bound method
http://www.sciencedirect.com/science/article/B6VCT-4YJCKSY-6/2/e7b6f4507d775c358aefbbc05dc04059
Long, Jiancheng
Gao, Ziyou
Zhang, Haozhi
Szeto, W.Y.
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:435-4442010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:435-444
article
ACUTA: A novel method for eliciting additive value functions on the basis of holistic preference statements
In multiple criteria decision aiding, it is common to use methods that are capable of automatically extracting a decision or evaluation model from partial information provided by the decision maker about a preference structure. In general, there is more than one possible model, leading to an indetermination which is dealt with sometimes arbitrarily in existing methods. This paper aims at filling this theoretical gap: we present a novel method, based on the computation of the analytic center of a polyhedron, for the selection of additive value functions that are compatible with holistic assessments of preferences. We demonstrate the most important characteristics of this technique with an experimental and comparative study of several existing methods belonging to the UTA family.
Multiple criteria decision analysis Learning based procedure Aggregation-disaggregation Analytic center of a polyhedron UTA method Additive utility model
http://www.sciencedirect.com/science/article/B6VCT-4YJCKSY-2/2/f1977506fb38f08e995c589bc6d54adc
Bous, Géraldine
Fortemps, Philippe
Glineur, François
Pirlot, Marc
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:488-4952010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:488-495
article
Developing a market-based approach to managing the US strategic petroleum reserve
The Strategic Petroleum Reserve has not been used effectively to manage the consequences of oil shocks in the United States. The main reason is that political decision makers tend to hoard the reserves during crises and bureaucratic processes delay the sale of the reserves. Also, the enabling legislation focused on ameliorating shortages whereas disruptions result price spikes rather than shortages. We develop a Markov game of the buildup and drawdown of the reserve in which a public player aims to maximize consumer welfare at the same time private holders of inventory maximize their profit. The methodological contribution in this paper is the development of financial options to implement the public player's optimal policy. We use the solution of this game to calculate the number and value of options necessary for the private marketplace to trigger the optimal buildup and drawdown of the reserve.
Markov processes OR in government OR in natural resources OR in energy
http://www.sciencedirect.com/science/article/B6VCT-4YH99MY-1/2/7bf99f867fed792b2e175eca16bb934b
Murphy, Frederic
Oliveira, Fernando S.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:54-632010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:54-63
article
Algorithms for the generalized quadratic assignment problem combining Lagrangean decomposition and the Reformulation-Linearization Technique
In this paper, we propose two exact algorithms for the GQAP (generalized quadratic assignment problem). In this problem, given M facilities and N locations, the facility space requirements, the location available space, the facility installation costs, the flows between facilities, and the distance costs between locations, one must assign each facility to exactly one location so that each location has sufficient space for all facilities assigned to it and the sum of the products of the facility flows by the corresponding distance costs plus the sum of the installation costs is minimized. This problem generalizes the well-known quadratic assignment problem (QAP). Both exact algorithms combine a previously proposed branch-and-bound scheme with a new Lagrangean relaxation procedure over a known RLT (Reformulation-Linearization Technique) formulation. We also apply transformational lower bounding techniques to improve the performance of the new procedure. We report detailed experimental results where 19 out of 21 instances with up to 35 facilities are solved in up to a few days of running time. Six of these instances were open.
Quadratic assignment Lagrangean decomposition Reformulation-Linearization Technique Branch-and-bound
http://www.sciencedirect.com/science/article/B6VCT-4YC80RS-1/2/b3612e57f2b43d72dd5e5770f47600f4
Pessoa, Artur Alves
Hahn, Peter M.
Guignard, Monique
Zhu, Yi-Rong
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:709-7182010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:709-718
article
Determining targets for multi-stage adaptive tests using integer programming
This paper considers a multi-stage adaptive test (MST) where the testlets at each stage are determined prior to the administration. The assembly of a MST requires target information and target response functions for the MST design. The targets are chosen to create tests with accurate scoring and high utilization of items in an operational pool. Forcing all MSTs to have information and response function plots to be within an interval about the targets will yield parallel MSTs, in the sense that standardized paper-and-pencil tests are considered parallel. The objective of this paper is to present a method to determine targets for the MST design based on an item pool and an assumed distribution of examinee ability. The approach is applied to a Skills Readiness Inventory test designed to identify logical reasoning deficiencies of examinees. This method can be applied to obtain item response theory targets for a linear test as this is a special case of a MST.
Integer programming Simulation Testing Item response theory Poisson trials
http://www.sciencedirect.com/science/article/B6VCT-4XX23NS-1/2/e604ffbe557ef9fda14e15ba66f4879d
Armstrong, Ronald D.
Kung, Mabel T.
Roussos, Louis A.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:699-7082010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:699-708
article
An integer programming model for two- and three-stage two-dimensional cutting stock problems
In this paper, an integer programming model for two-dimensional cutting stock problems is proposed. In the problems addressed, it is intended to cut a set of small rectangular items of given sizes from a set of larger rectangular plates in such a way that the total number of used plates is minimized. The two-stage and three-stage, exact and non-exact, problems are considered. Other issues are also addressed, as the rotation of items, the length of the cuts and the value of the remaining plates. The new integer programming model can be seen as an extension of the "one-cut model" proposed by Dyckhoff for the one-dimensional cutting stock problem. In the proposed model, each decision variable is associated with cutting one item from a plate or from a part of a plate resulting from previous cuts (residual plates). Comparative computational results of the proposed model and of models from the literature are presented and discussed.
Cutting 2D rectangular SSSCSP with guillotine constraints Integer programming Length of the cutting operations
http://www.sciencedirect.com/science/article/B6VCT-4Y8G5VG-2/2/86957f5daa70b7a207a8398bf422d474
Silva, Elsa
Alvelos, Filipe
Valério de Carvalho, J.M.
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:384-3942010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:384-394
article
Hybrid block replacement and inspection policies for a multi-component system with heterogeneous component lives
Novel replacement policies that are hybrids of inspection maintenance and block replacement are developed for an n identical component series system in which the component parts used at successive replacements arise from a heterogeneous population. The heterogeneous nature of components implies a mixed distribution for time to failure. In these circumstances, a hybrid policy comprising two phases, an early inspection phase and a later wear-out replacement phase, may be appropriate. The policy has some similarity to burn-in maintenance. The simplest policy described is such a hybrid and comprises a block-type or periodic replacement policy with an embedded block or periodic inspection policy. We use a three state failure model, in which a component may be good, defective or failed, in order to consider inspection maintenance. Hybrid block replacement and age-based inspection, and opportunistic hybrid policies will also arise naturally in these circumstances and these are briefly investigated. For the simplest policy, an approximation is used to determine the long-run cost and the system reliability. The policies have the interesting property that the system reliability may be a maximum when the long-run cost is close to its minimum. The failure model implies that the effect of maintenance is heterogeneous. The policies themselves imply that maintenance is carried out more prudently to newer than to older systems. The maintenance of traction motor bearings on underground trains is used to illustrate the ideas in the paper.
Block replacement Age-based replacement Multi-component system Maintenance Inspection Mixtures
http://www.sciencedirect.com/science/article/B6VCT-4YF5R5J-2/2/bd99fbb724ade9691c1c131d0b649743
Scarf, Philip A.
Cavalcante, Cristiano A.V.
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:445-4552010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:445-455
article
Rough support vector regression
This paper describes the relationship between support vector regression (SVR) and rough (or interval) patterns. SVR is the prediction component of the support vector techniques. Rough patterns are based on the notion of rough values, which consist of upper and lower bounds, and are used to effectively represent a range of variable values. Predictions of rough values in a variety of different forms within the context of interval algebra and fuzzy theory are attracting research interest. An extension of SVR, called rough support vector regression (RSVR), is proposed to improve the modeling of rough patterns. In particular, it is argued that the upper and lower bounds should be modeled separately. The proposal is shown to be a more flexible version of lower possibilistic regression model using [epsilon]-insensitivity. Experimental results on the Dow Jones Industrial Average demonstrate the suggested RSVR modeling technique.
Rough set Rough value Support vector machine Prediction Possiblistic regression Support vector regression
http://www.sciencedirect.com/science/article/B6VCT-4XM6K93-2/2/76b32c1221ead83f4852fc0a597fb8eb
Lingras, P.
Butz, C.J.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:670-6792010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:670-679
article
Multi-objective decision analysis for competence-oriented project portfolio selection
This paper develops a multi-objective optimization model for project portfolio selection taking employee competencies and their evolution into account. The objectives can include economic gains as well as gains expressed in terms of aggregated competence increments according to pre-defined profiles. In order to determine Pareto-optimal solutions, the overall problem is decomposed into a master problem addressing the portfolio selection itself, and a slave problem dealing with a suitable assignment of personnel to the work packages of the selected projects over time. We provide an asymptotic approximation of the problem by a linearized formulation, which allows an efficient and exact solution of the slave problem. For the solution of the master problem, we compare the multi-objective metaheuristics NSGA-II and P-ACO. Experimental results both for synthetically generated test instances and for real-world test instances, based on an application case from the E-Commerce Competence Center Austria, are presented.
Multiple criteria analysis Competence development Metaheuristics Project portfolios Staff scheduling
http://www.sciencedirect.com/science/article/B6VCT-4Y95V17-2/2/9e15da6a2fa20bb3e2751f92244afd87
Gutjahr, Walter J.
Katzensteiner, Stefan
Reiter, Peter
Stummer, Christian
Denk, Michaela
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:426-4342010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:426-434
article
NAUTILUS method: An interactive technique in multiobjective optimization based on the nadir point
Most interactive methods developed for solving multiobjective optimization problems sequentially generate Pareto optimal or nondominated vectors and the decision maker must always allow impairment in at least one objective function to get a new solution. The NAUTILUS method proposed is based on the assumptions that past experiences affect decision makers' hopes and that people do not react symmetrically to gains and losses. Therefore, some decision makers may prefer to start from the worst possible objective values and to improve every objective step by step according to their preferences. In NAUTILUS, starting from the nadir point, a solution is obtained at each iteration which dominates the previous one. Although only the last solution will be Pareto optimal, the decision maker never looses sight of the Pareto optimal set, and the search is oriented so that (s)he progressively focusses on the preferred part of the Pareto optimal set. Each new solution is obtained by minimizing an achievement scalarizing function including preferences about desired improvements in objective function values. NAUTILUS is specially suitable for avoiding undesired anchoring effects, for example in negotiation support problems, or just as a means of finding an initial Pareto optimal solution for any interactive procedure. An illustrative example demonstrates how this new method iterates.
Multiple objective programming Interactive methods Reference point methods Preference information Pareto optimality
http://www.sciencedirect.com/science/article/B6VCT-4YJCKSY-3/2/39f9857f7fd92aa3fd71193bea10cc92
Miettinen, Kaisa
Eskelinen, Petri
Ruiz, Francisco
Luque, Mariano
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:507-5212010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:507-521
article
Speeding up continuous GRASP
Continuous GRASP (C-GRASP) is a stochastic local search metaheuristic for finding cost-efficient solutions to continuous global optimization problems subject to box constraints (Hirsch et al., 2007). Like a greedy randomized adaptive search procedure (GRASP), a C-GRASP is a multi-start procedure where a starting solution for local improvement is constructed in a greedy randomized fashion. In this paper, we describe several improvements that speed up the original C-GRASP and make it more robust. We compare the new C-GRASP with the original version as well as with other algorithms from the recent literature on a set of benchmark multimodal test functions whose global minima are known. Hart's sequential stopping rule (1998) is implemented and C-GRASP is shown to converge on all test problems.
GRASP Continuous GRASP Global optimization Multimodal functions Continuous optimization Heuristic Stochastic algorithm Stochastic local search Nonlinear programming
http://www.sciencedirect.com/science/article/B6VCT-4YCG024-1/2/019f43f30d12f976dc379a761207704b
Hirsch, M.J.
Pardalos, P.M.
Resende, M.G.C.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:729-7332010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:729-733
article
Modified piecewise linear DEA model
Recently, Cook and Zhu have proposed the Piecewise Linear Data Envelopment Analysis (PL-DEA) model, a situation in which a generalization of the DEA methodology which incorporates piecewise linear functions of factors is considered. Standard DEA models provide an efficiency score and targets for an inefficient unit, but the PL-DEA model fails to produce acceptable targets. Thus, this issue has been considered in the piecewise linear CCR model, in which a non-increasing set of multipliers describe the weight function. Also, the piecewise linear CCR model has been enhanced by introducing two MIP models for a two-stage procedure in order to set targets precisely. Furthermore as it follows, the above-mentioned models are compared with each other and an example is provided for the sake of lucidity.
Data envelopment analysis Target Trade-offs Marginal Value Piecewise linear function
http://www.sciencedirect.com/science/article/B6VCT-4Y4R309-3/2/1dbe35c2e6358d73ae6f9e13bc803b81
Lotfi, F. Hosseinzadeh
Rostamy-Malkhalifeh, M.
Moghaddas, Z.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:719-7282010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:719-728
article
Comparing efficiency across markets: An extension and critique of the methodology
The use of non-parametric frontier methods for the evaluation of product market efficiency in heterogeneous markets seems to have gained some popularity recently. However, the statistical properties of these frontier estimators have been largely ignored. The main point is that non-parametric frontier estimators are biased and that the degree of bias depends on specific sample properties, most importantly sample size and number of dimensions of the model. To investigate the effect of this bias on comparing market efficiency, this contribution estimates the efficiency for several datasets for two main product categories. Following (Zhang, Y., Bartels, R., 1998. The effect of sample size on the mean efficiency in DEA with an application to electricity distribution in Australia, Sweden and New Zealand. Journal of Productivity Analysis, 9(3), 187-204.), these results comprise re-estimates for the larger samples limiting their size to that of the smaller samples when the model dimensions for different samples are identical. Furthermore, sample sizes are adjusted to mitigate the eventual differences in dimensions in specification. This allows comparing market efficiency for different markets on a more equal footing, since it reduces the bias effect to a minimum making the comparison of market efficiency possible. However, the article also points out the critical limitations of this [Zhang, Y., Bartels, R., (1998). The effect of sample size on the mean efficiency in DEA with an application to electricity distribution in Australia, Sweden and New Zealand. Journal of Productivity Analysis 9 (3), 187-204] approach in certain respects. Apart from reporting these negative results, we also offer some suggestions for future work.
Market efficiency Heterogeneous product markets Bias Monte Carlo simulation
http://www.sciencedirect.com/science/article/B6VCT-4Y4PVM1-3/2/4110a967993ea48f134a59cf5e24a3dd
Chumpitaz, Ruben
Kerstens, Kristiaan
Paparoidamis, Nicholas
Staat, Matthias
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:104-1102010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:104-110
article
Monge extensions of cooperation and communication structures
Cooperation structures without any a priori assumptions on the combinatorial structure of feasible coalitions are studied and a general theory for marginal values, cores and convexity is established. The theory is based on the notion of a Monge extension of a general characteristic function, which is equivalent to the Lovász extension in the special situation of a classical cooperative game. It is shown that convexity of a cooperation structure is tantamount to the equality of the associated core and Weber set. Extending Myerson's graph model for game theoretic communication, general communication structures are introduced and it is shown that a notion of supermodularity exists for this class that characterizes convexity and properly extends Shapley's convexity model for classical cooperative games.
91A12 91A40 Communication structure Convex game Cooperation structure Monge extension Lovasz extension Marginal value Ranking Shapley value Supermodularity Weber set
http://www.sciencedirect.com/science/article/B6VCT-4Y9CF8M-3/2/49b12ee824a5f23c020b8fb962dc9833
Faigle, U.
Grabisch, M.
Heyne, M.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:661-6692010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:661-669
article
Optimizing strategic behaviour in a dynamic setting in professional team sports
This article develops a dynamic game-theoretic model of optimizing strategic behaviour by football (soccer) teams. Teams choose between defensive and attacking formations and between a non-violent and a violent playing style, and can vary these choices continuously throughout each match. Starting from the end of the match and working backwards, the teams' optimal strategies conditional on the current state of the match are determined by solving a series of two-player non-cooperative subgames. Numerical simulations are used to explore the sensitivity of strategic behaviour to variations in the structural parameters. The analysis demonstrates that the strategic behaviour of football teams can be rationalized in accordance with game-theoretic principles of optimizing strategic behaviour by agents when payoffs are uncertain and interdependent.
Economics Game theory Sport (Football)
http://www.sciencedirect.com/science/article/B6VCT-4Y70C5Y-3/2/77ea26b48db4f897def664dde8ba0efb
Dobson, Stephen
Goddard, John
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:209-2202010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:209-220
article
Stakeholder preference elicitation and modelling in multi-criteria decision analysis - A case study on urban water supply
Integration of multiple objectives to evaluate the alternative operating rules for urban water supply reservoir systems can be effectively accomplished by multi-criteria decision aid techniques, where preference elicitation and modelling plays an important role. This paper describes a preference elicitation and modelling procedure involving the multi-criteria outranking method PROMETHEE in evaluating these alternative operating rules. The Melbourne water supply system was considered as the case study. Eight performance measures (PMs) were identified under four main objectives to evaluate the system performance under alternative operating rules. Three major hypothetical stakeholder groups namely, resource managers, water users, and environmental interest groups were considered in decision-making. An interviewer-assisted questionnaire survey was used to derive the preference functions and weights of the PMs. The evaluation of alternative operating rules is not covered in this paper, rather an approach to elicit and model stakeholder preferences in decision-making is described.
Multiple criteria analysis Stakeholder preference elicitation Urban water supply systems
http://www.sciencedirect.com/science/article/B6VCT-4YDYSGF-1/2/fbf14cb81796d2c06ab9d91e54f35d0b
Kodikara, P.N.
Perera, B.J.C.
Kularathna, M.D.U.P.
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:579-5852010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:579-585
article
Analysis and design of sequencing rules for car sequencing
This paper presents novel approaches for generating sequencing rules for the car sequencing (CS) problem in cases of two and multiple processing times per station. The CS problem decides on the succession of different car models launched down a mixed-model assembly line. It aims to avoid work overloads at the stations of the line by applying so-called sequencing rules, which restrict the maximum occurrence of labor-intensive options in a subsequence of a certain length. Thus to successfully avoid work overloads, suitable sequencing rules are essential. The paper shows that the only existing rule generation approach leads to sequencing rules which misclassify feasible sequences. We present a novel procedure which overcomes this drawback by generating multiple sequencing rules. Then, it is shown how to apply both procedures in case of multiple processing times per station. For both cases analytical and empirical results are derived to compare classification quality.
Mixed-model assembly lines Car sequencing Sequencing rules
http://www.sciencedirect.com/science/article/B6VCT-4YM7FH3-2/2/67c964cb85aa7959b8efa385d830ef9f
Golle, Uli
Boysen, Nils
Rothlauf, Franz
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:374-3832010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:374-383
article
Contracting with an urgent supplier under cost information asymmetry
We investigate a contract setting problem faced by a manufacturer who can procure major modules from an overseas supplier, as well as a local supplier. The overseas supplier is prime and offers quality products, whereas the local supplier is viewed only as a backup, and its products are inferior in quality. As the local supplier needs to put in additional effort to fulfill the urgent orders, it is difficult for the manufacturer to estimate this urgent supplier's production cost. This asymmetric cost information becomes an obstacle for the manufacturer in managing the urgent supplier. In this paper, we study two types of contingent contracts. One is the common price-only contract, and the other is a contract menu consisting of a transfer payment and a lead time quotation. We construct a Stackelberg game model and evaluate how the involvement of an urgent supplier with private cost information affects performances of the prime supplier and the manufacturer in different scenarios (with or without the urgent supplier, under different contingent contracts). We also conduct numerical experiments to show how the parameters of the contracts affect profits of the manufacturer.
Game theory Optimization Decision analysis Asymmetric information
http://www.sciencedirect.com/science/article/B6VCT-4YK7J2M-1/2/758a0f45edc58205aca18e2096dac20c
Xu, He
Shi, Ning
Ma, Shi-hua
Lai, Kin Keung
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:555-5612010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:555-561
article
Online scheduling of malleable parallel jobs with setup times on two identical machines
In this paper we consider online scheduling of malleable parallel jobs on two identical machines, where jobs arrive over time. Each job Jj has an execution time tj=pj/kj+(kj-1)cj when it is processed on kj machines, where pj>0 and cj>0 are the length and setup time of job Jj. The objective is to minimize the makespan. For the problem with two machines, we present an online algorithm with competitive ratio of 1+[alpha], where . We show that 1+[alpha] is a lower bound on the competitive ratio of any online algorithm for the problem with machines. So our algorithm is optimal for the case of two machines.
Scheduling Parallel jobs Setup times Online algorithm Competitive analysis
http://www.sciencedirect.com/science/article/B6VCT-4YJ4N9T-4/2/458026e14835c4874ff3c4efb31562e6
Guo, Shouwei
Kang, Liying
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:265-2682010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:265-268
article
On the boundedness of the SORM DEA models with negative data
Emrouznejad et al. (2010) proposed a Semi-Oriented Radial Measure (SORM) model for assessing the efficiency of Decision Making Units (DMUs) by Data Envelopment Analysis (DEA) with negative data. This paper provides a necessary and sufficient condition for boundedness of the input and output oriented SORM models.
Data envelopment analysis Negative data Semi-Oriented Radial Measure Boundedness
http://www.sciencedirect.com/science/article/B6VCT-4YC1K3P-1/2/96ea2213afa2f3906c798f3793589515
Emrouznejad, Ali
Amin, Gholam R.
Thanassoulis, Emmanuel
Anouze, Abdel Latef
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:509-5212010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:509-521
article
The evolution of cell formation problem methodologies based on recent studies (1997-2008): Review and directions for future research
This paper presents a literature review of the cell formation (CF) problem concentrating on formulations proposed in the last decade. It refers to a number of solution approaches that have been employed for CF such as mathematical programming, heuristic and metaheuristic methodologies and artificial intelligence strategies. A comparison and evaluation of all methodologies is attempted and some shortcomings are highlighted. Finally, suggestions for future research are proposed useful for CF researchers.
Group technology Cellular manufacturing systems Cell formation problem
http://www.sciencedirect.com/science/article/B6VCT-4XM6K93-1/2/b4dc5be68b0bab96a41ea00fa7813a62
Papaioannou, Grammatoula
Wilson, John M.
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:691-7012010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:691-701
article
Optimization and analysis of the profitability of tariff structures with two-part tariffs
Service providers often offer tariff structures with several two-part tariffs that consist of a fixed fee and a usage price, such that consumers may pick the tariff they prefer. Prices of tariffs have significant impacts on service providers' profit, because they simultaneously influence consumers' tariff choices and their usage. The number of tariffs also plays an important role, because more tariffs segment the market better but also increase the administrative burden and require more marketing effort. This article presents a mixed-integer nonlinear programming optimization problem to determine profit-maximizing tariffs; compares several heuristic search methods, in particular, the gradient method, stochastic search, and simulated annealing, to solve this problem; analyses the profitability of different tariff structures; and outlines the factors that drive differences in profitability across various tariff structures. The results show that especially for large samples of more than 100 consumers, simulated annealing performs best and deviates only 0.2% from the optimum. Structures with fewer two-part tariffs are generally sufficient, because additional two-part tariffs only negligibly increase service providers' profit.
Marketing Pricing Two-part tariffs Mixed integer nonlinear programming
http://www.sciencedirect.com/science/article/B6VCT-4YRHCS3-1/2/f75bb7a9ebabfb926e9949fc8db61950
Schlereth, Christian
Stepanchuk, Tanja
Skiera, Bernd
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:1-102010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:1-10
article
Synergies of Operations Research and Data Mining
In this contribution we identify the synergies of Operations Research and Data Mining. Synergies can be achieved by integration of optimization techniques into Data Mining and vice versa. In particular, we define three classes of synergies and illustrate each of them by examples. The classification is based on a generic description of aims, preconditions as well as process models of Operations Research and Data Mining. It serves as a framework for the assessment of approaches at the intersection of the two procedures.
Data Mining
http://www.sciencedirect.com/science/article/B6VCT-4XJ69PH-1/2/bc6098a432604607bc22748b850fb7b3
Meisel, Stephan
Mattfeld, Dirk
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:329-3402010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:329-340
article
Supply quality management with wholesale price and revenue-sharing contracts under horizontal competition
In a number of industries (e.g., the airplane industry, aerospace industry, auto industry, or computer industry), certain suppliers essentially have a monopoly on the production technology for key components, and inevitably manufacturers in these industries have common suppliers. A key part of manufacturers' work with suppliers concerns improving the quality of their respective products, which gives rise to a collaborative activity usually termed as "supply quality management". When the manufacturers are competitors, they do not wish to see a common supplier dividing his involvement in quality improvement unequally between themselves and their rivals. However, as the suppliers collaborate with several manufacturers, it is highly questionable whether their efforts will be strictly equivalent for each manufacturer. In this paper, a non-cooperative dynamic game is formulated in which a single supplier collaborates with two manufacturers on design quality improvements for their respective products. The manufacturers compete for market demand both on price and design quality. The paper analyzes how each party should allocate resources for quality improvement over time. In order to take into account the potential coordinating power of the compensation scheme adopted in this type of decentralized setting, we compare the possible outcomes under a wholesale price contract and a revenue-sharing contract.
Design quality Supply quality management Horizontal competition Wholesale price contract Revenue sharing contract
http://www.sciencedirect.com/science/article/B6VCT-4YHNYXM-2/2/fc68d49754f92f49c5f2908e09c9a9bb
El Ouardighi, Fouad
Kim, Bowon
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:407-4162010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:407-416
article
Determining optimal replacement time for metal cutting tools
Traditional tool life models do not take into account the variation inherent in metal cutting processes. As a consequence, the real tool life rarely matches the predicted values. To compensate for this uncertainty, tools are usually replaced prematurely, which leads to unnecessarily high tool costs. In some cases, however, wear-out occurs earlier than predicted, which imposes a risk of workpiece damage or rework and can lead to other extra charges. To balance these costs, this paper proposes an age replacement model. It is assumed that penalty costs are incurred each time a tool fails before the planned replacement. The probability of such an event is determined from the tool reliability function, which models the wear-out by a mixture of Weibull distributions, while failures due to external stresses are accounted for by a homogeneous Poisson process. The optimal replacement time is then determined from a total time on test (TTT) plot. The adequacy of the proposed approach for practical application is tested and confirmed in a case study on turning of Inconel 718 with cubic boron nitride (CBN) tools.
Cutting tool Replacement Weibull distribution TTT transform CBN
http://www.sciencedirect.com/science/article/B6VCT-4YM7FH3-3/2/969f2a2b62aa181c055e4d26d749acb2
Vagnorius, Zydrunas
Rausand, Marvin
Sørby, Knut
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:131-1432010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:131-143
article
Optimal testing strategies in overlapped design process
Testing is an important activity in product development. Past studies, which are developed to determine the optimal scheduling of tests, often focused on single-stage testing of sequential design process. This paper presents an analytical model for the scheduling of tests in overlapped design process, where a downstream stage starts before the completion of upstream testing. We derive optimal stopping rules for upstream and downstream stages' testing, together with the optimal time elapsed between beginning the upstream tests and beginning the downstream development. We find that the cost function is first convex then concave increasing with respect to upstream testing duration. A one-dimensional search algorithm is then proposed for finding the unique optimum that minimizes the overall cost. Moreover, the impact of different model parameters, such as the problem-solving capacity and opportunity cost, on the optimal solution is discussed. Finally, we compare the testing strategies in overlapped process with those in sequential process, and get some additional results. The methodology is illustrated with a case study at a handset design company.
Product development Multi-stage tests Problem-solving Concurrent engineering Overlapping
http://www.sciencedirect.com/science/article/B6VCT-4YFCF7D-2/2/9ecaede2f0364c5da60c7a09a5c990d4
Qian, Yanjun
Xie, Min
Goh, Thong Ngee
Lin, Jun
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:703-7072010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:703-707
article
A branch-and-bound algorithm to minimize the line length of a two-sided assembly line
A new branch-and-bound algorithm is presented to solve the two-sided assembly line balancing problem of type 1 (TALB-1). First, a pair of two directly facing station is defined as a position, and then the two-sided assembly line (TAL) is relaxed to a one-sided assembly line (OAL). Some new lower bound on positions are computed, and dominance rules and reduction rules for the one-sided assembly line balancing problem of type 1 (OALB-1) are extended and incorporated into a station-oriented assignment procedure for the TALB-1 problem. Finally, the tests are carried out on a well-known benchmark set of problem instances, and experimental results demonstrate that the proposed procedure is efficient.
Manufacturing Branch-and-bound Assembly line balancing Two-sided assembly line
http://www.sciencedirect.com/science/article/B6VCT-4YH569R-4/2/3b0a45c99e25ba1ca330f4be7caf7a53
Xiaofeng, Hu
Erfei, Wu
Jinsong, Bao
Ye, Jin
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:615-6242010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:615-624
article
Optimization of component reliability in the design phase of capital goods
We introduce a quantitative model to support the decision on the reliability level of a critical component during its design. We consider an OEM who is responsible for the availability of its systems in the field through service contracts. Upon a failure of a critical part in a system during the exploitation phase, the failed part is replaced by a ready-for-use part from a spare parts inventory. In an out-of-stock situation, a costly emergency procedure is applied. The reliability levels and spare parts inventory levels of the critical components are the two main factors that determine the downtime and corresponding costs of the systems. These two levels are decision variables in our model. We formulate the portions of Life Cycle Costs (LCC) which are affected by a component's reliability and its spare parts inventory level. These costs consist of design costs, production costs, and maintenance and downtime costs in the exploitation phase. We conduct exact analysis and provide an efficient optimization algorithm. We provide managerial insights through a numerical experiment which is based on real-life data.
Capital goods Reliability Spare parts inventory Life cycle costs
http://www.sciencedirect.com/science/article/B6VCT-4Y88D9S-1/2/cdd79a77747c7506b9939fe968aa5336
Öner, K.B.
Kiesmüller, G.P.
van Houtum, G.J.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:93-1032010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:93-103
article
On the benefits of co-collection: Experiments with a multi-compartment vehicle routing algorithm
The Multi-Compartment Vehicle Routing Problem involves clients with a demand for different products and vehicles with several compartments to co-transport these commodities. We present a local search procedure that explores well-known moves (2-opt, cross, exchange, relocate), and exploits the mechanisms of neighbour lists and marking to speed up the searches. We combine the procedure with the Guided Local Search meta-heuristic to improve solution quality. Extensive computational results are reported to uncover when co-distribution by vehicles with multiple compartments is better than separate distribution with un-partitioned trucks. Sensitivities in key problem parameters including, client density and location of the depot, vehicle capacity, client demand and number of commodities are investigated.
Routing Multi-compartment routing Meta-heuristics Guided Local Search Co-collection Separate collection
http://www.sciencedirect.com/science/article/B6VCT-4YDKJW6-4/2/f63a0c0694ba5797fc2c85fd215439f2
Muyldermans, L.
Pang, G.
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:653-6662010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:653-666
article
Valuation of project portfolios: An endogenously discounted method
Real options analysis (ROA) has been developed to value assets in which managerial flexibilities create significant value. The methodology is ideal for the valuation of projects in which frequent adjustments (e.g. investment deferral, project scope changes, etc) are necessary in response to the realization of market and technological uncertainties. However, ROA has no practical application when valuing portfolios of multiple concurrent projects sharing resources, as the size of the problem grows exponentially with the number of projects and the length of the time horizon. In this paper an extension of ROA suitable for the valuation of project portfolios with substantial technological uncertainty (e.g. R&D portfolios) is proposed. The method exploits the distributed decision making strategy encountered in most organizations to decompose the portfolio valuation problem into a decision-making sub-problem and a set of single project valuation sub-problems that can be sequentially solved. Discrete event simulation is used for the first sub-problem, while a tailored ROA based strategy is used for the set of valuation sub-problems. A case study from the pharmaceutical industry is used to compare the decision tree analysis (DTA) method and the proposed method.
Real options analysis Portfolio Projects Simulation Decision analysis Finance
http://www.sciencedirect.com/science/article/B6VCT-4YKGJ4S-1/2/a5a9b3e83dfb36a9bae648458c873c20
Zapata, Juan C.
Reklaitis, Gintaras V.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:123-1302010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:123-130
article
The pricing and optimal strategies of callable warrants
In this paper, we introduce a valuation model of callable warrants under a setting of the optimal stopping problem between the holder (investor) and the issuer (firm). A warrant is the right to purchase new shares at a predetermined price. When the new stocks are issued, the value of the stock is diluted. We consider the model taking the dilution into account. After identifying optimal policies for the issuer and the investor, we explore the analytical properties of the optimal exercise and call boundaries for the holder and the issuer, respectively. Furthermore, the value of such a callable warrant and the optimal critical prices are examined numerically using the binomial method.
Finance Warrants Call clauses Optimal stopping problem Optimal boundary Decomposition of price
http://www.sciencedirect.com/science/article/B6VCT-4YCWNKT-1/2/a3607a90c8dc9a74e16342f7137a2217
Yagi, Kyoko
Sawaki, Katsushige
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:686-6902010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:686-690
article
Time substitution with application to data envelopment analysis
In this paper we analyze resource allocation distinguishing between the decision of when to begin allocation and over how many periods to apply the resources. We present analytical results for specific production technologies under different returns to scale assumptions, under capacity constraints and for production with technical change. Using a dynamic activity analysis framework we show how to compute in general optimal solutions for resource intensity use.
C61 D92 Time substitution Intertemporal optimization Data envelopment analysis
http://www.sciencedirect.com/science/article/B6VCT-4YPPR1C-1/2/9d9d5bdce302c1b82f5921707533dfe5
Färe, R.
Grosskopf, S.
Margaritis, D.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:73-852010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:73-85
article
Validating vehicle routing zone construction using Monte Carlo simulation
The primary purpose of this paper is to validate a clustering procedure used to construct contiguous vehicle routing zones (VRZs) in metropolitan regions. Given a set of customers with random demand for pickups and deliveries over the day, the goal of the design problem is to cluster the customers into zones that can be serviced by a single vehicle. Monte Carlo simulation is used to determine the feasibility of the zones with respect to package count and tour time. For each replication, a separate probabilistic traveling salesman problem (TSP) is solved for each zone. For the case where deliveries must precede pickups, a heuristic approach to the TSP is developed and evaluated, also using Monte Carlo simulation. In the testing, performance is measured by overall travel costs and the probability of constraint violations. Gaps in tour length, tour time and tour cost are the measure used when comparing exact and heuristic TSP solutions. To test the methodology, a series of experiments were conducted using data provided by a leading shipping carrier for the Pittsburgh area. Currently, the region is divided into 73 VRZs, compared to 64 indicated by the clustering procedure. The simulation results showed that a redesign would yield approximately $334,360 in annual savings without any noticeable deterioration in service. In addition, when the heuristic TSP model was solved in place of the exact model, the average gap in tour duration increased by only 0.16Â hours and 0.2Â hours for the cases of 73 clusters and 64 clusters, respectively, indicating a small upward bias. However, runtimes decreased by almost 70%.
Vehicle routing zones Monte Carlo simulation Traveling salesman problem Clustering analysis Pickup and delivery operations
http://www.sciencedirect.com/science/article/B6VCT-4YDKJW6-1/2/41c812dbeaf4c0bcca31e19b0a9b472b
Bard, Jonathan F.
Jarrah, Ahmad I.
Zan, Jing
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:501-5062010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:501-506
article
Projected subgradient techniques and viscosity methods for optimization with variational inequality constraints
In this paper, we propose an easily implementable algorithm in Hilbert spaces for solving some classical monotone variational inequality problem over the set of solutions of mixed variational inequalities. The proposed method combines two strategies: projected subgradient techniques and viscosity-type approximations. The involved stepsizes are controlled and a strong convergence theorem is established under very classical assumptions. Our algorithm can be applied for instance to some mathematical programs with complementarity constraints.
Hierarchical problem Projected subgradient method Nonsmooth optimization Viscosity method Paramonotone operator Mixed variational inequality Complementarity constraints
http://www.sciencedirect.com/science/article/B6VCT-4Y9CF8M-2/2/4134f213eab07a29836c5de18945f94d
Maingé, Paul-Emile
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:547-5542010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:547-554
article
Min sum clustering with penalties
Given a complete graph G=(V,E), a weight function on its edges, and a penalty function on its vertices, the penalized k-min-sum problem is the problem of finding a partition of V to k+1 sets, S1,...,Sk+1, minimizing , where for , and p(S)=[summation operator]i[set membership, variant]Spi. Our main result is a randomized approximation scheme for the metric version of the penalized 1-min-sum problem, when the ratio between the minimal and maximal penalty is bounded. For the metric penalized k-min-sum problem where k is a constant, we offer a 2-approximation.
Min sum clustering Outliers Randomized approximation scheme
http://www.sciencedirect.com/science/article/B6VCT-4YJCKSY-1/2/1957dc717a5ed5a499275c9f7f93bc3b
Hassin, Refael
Or, Einat
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:489-5002010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:489-500
article
Facilitated modelling in operational research
The traditional way of employing operational research in organisational interventions has been the expert mode. In this mode, the problem situation faced by the client is given to the operational research consultant, who then builds a model of the situation, solves the model to arrive at an optimal (or quasi-optimal) solution, and then provides a recommendation to the client based on the obtained solution. An alternative mode of engagement is to conduct the whole intervention together with the client: from structuring and defining the nature of the problem situation of interest, to supporting the evaluation of priorities and development of plans for subsequent implementation. In this latter mode, the operational researcher works throughout the intervention not only as an analyst, but also as a facilitator to the client. This paper discusses this latter mode of engagement with clients, with particular emphasis on the use of facilitated modelling as the intervention tool. Drawing on research scattered across a range of publications and domains, the review presented here provides a formal definition of facilitated modelling, together with a general framework that allows the conceptualisation of a wide variety of facilitated modelling approaches to organisational intervention. Design issues in facilitated modelling and their practical implication are discussed, and directions for future research identified.
Problem structuring Decision making Facilitation Modelling OR consultancy Organisational intervention
http://www.sciencedirect.com/science/article/B6VCT-4XB1T96-1/2/62f55d5de5db43754a1271666bc0286c
Franco, L. Alberto
Montibeller, Gilberto
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:680-6862010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:680-686
article
Using decision rules to achieve mass customization of airline services
This paper uses the Dominance-based Rough Set Approach (DRSA) to formulate airline service strategies by generating decision rules that model passenger preference for airline service quality. DRSA could help airlines eliminate some services associated with dispensable attributes without affecting passenger perception of service quality. DRSA could also help airlines achieve mass customization of airline services and generate additional revenues by active or passive targeting of quality services to passengers.
Dominance-based Rough Set Approach Multi Criteria Decision Making (MCDM) Data mining Decision rules Airline Service quality
http://www.sciencedirect.com/science/article/B6VCT-4XS6FFW-1/2/f9607bf4bc9ec542f4d5419e8713d42a
Liou, James J.H.
Yen, Leon
Tzeng, Gwo-Hshiung
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:614-6222010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:614-622
article
Optimal electronic musical instruments
For many musical instruments, a musician depresses various combinations of keys in order to play the notes in the instrument's range. For traditional (or acoustic) instruments of this type (e.g., woodwinds and most brass), the ways in which the combinations of keys can be assigned to the notes are limited by physics. However, for electronic instruments of this type, there are essentially no such limitations. In this paper, we exploit this freedom and present several designs for electronic instruments which are optimally easy to play; that is, the total movement of the fingers when playing some common sequences of notes (i.e., various, general collections of scales) is minimized. Our designs are built upon Gray codes, which are used in digital communications.
Combinatorial optimization Gray codes Musical instrument design
http://www.sciencedirect.com/science/article/B6VCT-4YJ6GF2-1/2/d92f6624926c263c393b0a719ce4f40f
Hartvigsen, David
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:650-6602010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:650-660
article
Optimal dynamic price selection under attraction choice models
We present a single-resource finite-horizon Markov decision process approach for a firm that seeks to maximize expected revenues by dynamically adjusting the menu of offered products and their prices to be selected from a finite set of alternative values predetermined as a matter of policy. Consumers choose among available products according to an attraction choice model, a special but widely applied class of discrete choice models. The fractional substructure inherent to attraction choice models enables the derivation of structural properties that significantly simplify the computation of an optimal policy. We show that the more capacity (or less time) is remaining, the lower are the optimal prices. We develop an exact solution procedure for preprocessing and recursively solving price selection problems that clearly outperforms current revenue management approaches with respect to computational complexity. Furthermore, we demonstrate that the potential revenue improvements from dynamic compared to fixed pricing can be significant, ranging from 4.5% up to 149% for selected examples from the literature. Extensions to multiple resources and to related discrete choice models are discussed.
Pricing Revenue management Stochastic multi-product dynamic pricing Discrete choice behavior Fractional programming
http://www.sciencedirect.com/science/article/B6VCT-4Y70C5Y-2/2/b98dfcd74829dbb203172f9c172ce3be
Schön, Cornelia
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:289-3002010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:289-300
article
A general variable neighborhood search for solving the uncapacitated single allocation p-hub median problem
We present a new general variable neighborhood search approach for the uncapacitated single allocation p-hub median problem in networks. This NP hard problem is concerned with locating hub facilities in order to minimize the traffic between all origin-destination pairs. We use three neighborhoods and efficiently update data structures for calculating new total flow in the network. In addition to the usual sequential strategy, a new nested strategy is proposed in designing a deterministic variable neighborhood descent local search. Our experimentation shows that general variable neighborhood search based heuristics outperform the best-known heuristics in terms of solution quality and computational effort. Moreover, we improve the best-known objective values for some large Australia Post and PlanetLab instances. Results with the new nested variable neighborhood descent show the best performance in solving very large test instances.
Variable neighborhood search Nested variable neighborhood descent Discrete location p-Hub median
http://www.sciencedirect.com/science/article/B6VCT-4YDT3XM-2/2/ce4a97b6ca67e3210deda72b58d3eac6
Ilic, Aleksandar
Urosevic, Dragan
Brimberg, Jack
Mladenovic, Nenad
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:584-5942010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:584-594
article
A travel demand management strategy: The downtown space reservation system
In this paper, a Travel Demand Management strategy known as the Downtown Space Reservation System (DSRS) is introduced. The purpose of this system is to facilitate the mitigation of traffic congestion in a cordon-based downtown area by requiring people who want to drive into this area to make reservations in advance. An integer programming formulation is provided to obtain the optimal mix of vehicles and trips that are characterized by a series of factors such as vehicle occupancy, departure time, and trip length with an objective of maximizing total system throughput and revenue. Based upon the optimal solution, an "intelligent" module is built using artificial neural networks that enables the transportation authority to make decisions in real time on whether to accept an incoming request. An example is provided that demonstrates that the solution of the "intelligent" module resembles the optimal solution with an acceptable error rate. Finally, implementation issues of the DSRS are addressed.
Transportation Travel demand management (TDM) Trip reservation Integer programming Neural networks
http://www.sciencedirect.com/science/article/B6VCT-4Y7P4KW-2/2/00cf98f7cb0645aee4709be81e17c477
Zhao, Y.
Triantis, K.
Teodorovic, D.
Edara, P.
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:687-6982010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:687-698
article
A systematic procedure to evaluate an automobile manufacturer-distributor partnership
Automobile manufacturer-distributor partnerships are fundamental to the success of automobile companies. The complexity of the overall partnership model often causes difficulties in partnership study. This paper presents a systematic procedure to evaluate an automobile manufacturer-distributor partnership consisting of a large number of system variables. Firstly, Interpretive Structure Modeling (ISM) is used to sort system variables into groups of various characteristics. This sorting process provides an effective means to develop a three-stage hierarchic/network model of the partnership, including Stage I: partnership selection, Stage II: partnership establishment, and Stage III: partnership maintenance. Secondly, Analytic Hierarchy Process (AHP)/Analytic Network Process (ANP) are applied to partnership evaluation based on as many as 20 system variables. Relative importance weight of all variables is quantitatively determined. The most investment-worthy variables found are management strength and power. Finally, this paper makes a comparison between the optimum distributors identified by the present procedure and in practical cases. The usefulness and efficiency of the proposed procedure are ascertained with highly consistent results in the comparison.
Marketing Partnership Analytic Hierarchy Process (AHP) Analytic Network Process (ANP) Interpretive Structure Modeling (ISM)
http://www.sciencedirect.com/science/article/B6VCT-4Y7MM1T-2/2/0d45592efe6aa942844de0f0be4ef505
Chen, Shuo-Pei
Wu, Wann-Yih
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:11-172010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:11-17
article
The inverse Fermat-Weber problem
Given n points in the plane with nonnegative weights, the inverse Fermat-Weber problem consists in changing the weights at minimum cost such that a prespecified point in the plane becomes the Euclidean 1-median. The cost is proportional to the increase or decrease of the corresponding weight. In case that the prespecified point does not coincide with one of the given n points, the inverse Fermat-Weber problem can be formulated as linear program. We derive a purely combinatorial algorithm which solves the inverse Fermat-Weber problem with unit cost using O(n) greedy-like iterations where each of them can be done in constant time if the points are sorted according to their slopes. If the prespecified point coincides with one of the given n points, it is shown that the corresponding inverse problem can be written as convex problem and hence is solvable in polynomial time to any fixed precision.
Location Linear programming Combinatorial optimization
http://www.sciencedirect.com/science/article/B6VCT-4YFCF7D-1/2/45a390b63d3ccfd80392f4130b329b30
Burkard, Rainer E.
Galavii, Mohammadreza
Gassner, Elisabeth
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:540-5512010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:540-551
article
Surrogate constraint normalization for the set covering problem
The set covering problem (SCP) is central in a wide variety of practical applications for which finding good feasible solutions quickly (often in real-time) is crucial. Surrogate constraint normalization is a classical technique used to derive appropriate weights for surrogate constraint relaxations in mathematical programming. This framework remains the core of the most effective constructive heuristics for the solution of the SCP chiefly represented by the widely-used Chvátal method. This paper introduces a number of normalization rules and demonstrates their superiority to the classical Chvátal rule, especially when solving large scale and real-world instances. Directions for new advances on the creation of more elaborate normalization rules for surrogate heuristics are also provided.
Surrogate constraints Constraint normalization Set covering problem Greedy knapsack heuristic Heuristics
http://www.sciencedirect.com/science/article/B6VCT-4YCS00V-1/2/5c059069a8a95b4493a75c83587441b1
Ablanedo-Rosas, José H.
Rego, César
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:395-4062010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:395-406
article
Adaptive multicut aggregation for two-stage stochastic linear programs with recourse
Outer linearization methods for two-stage stochastic linear programs with recourse, such as the L-shaped algorithm, generally apply a single optimality cut on the nonlinear objective at each major iteration, while the multicut version of the algorithm allows for several cuts to be placed at once. In general, the L-shaped algorithm tends to have more major iterations than the multicut algorithm. However, the trade-offs in terms of computational time are problem dependent. This paper investigates the computational trade-offs of adjusting the level of optimality cut aggregation from single cut to pure multicut. Specifically, an adaptive multicut algorithm that dynamically adjusts the aggregation level of the optimality cuts in the master program, is presented and tested on standard large-scale instances from the literature. Computational results reveal that a cut aggregation level that is between the single cut and the multicut can result in substantial computational savings over the single cut method.
Stochastic programming Multicut aggregation Adaptive cuts
http://www.sciencedirect.com/science/article/B6VCT-4YFCF7D-3/2/507405689b663b307b2055a43af3897e
Trukhanov, Svyatoslav
Ntaimo, Lewis
Schaefer, Andrew
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:313-3282010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:313-328
article
Inventory systems with stochastic demand and supply: Properties and approximations
We model a retailer whose supplier is subject to complete supply disruptions. We combine discrete-event uncertainty (disruptions) and continuous sources of uncertainty (stochastic demand or supply yield), which have different impacts on optimal inventory settings. This prevents optimal solutions from being found in closed form. We develop a closed-form approximate solution by focusing on a single stochastic period of demand or yield. We show how the familiar newsboy fractile is a critical trade-off in these systems, since the optimal base-stock policies balance inventory holding costs with the risk of shortage costs generated by a disruption.
Inventory Supply disruptions Risk management Supply chain management
http://www.sciencedirect.com/science/article/B6VCT-4YH569R-1/2/2d7d1ee31a336f9ff7395f96d2584955
Schmitt, Amanda J.
Snyder, Lawrence V.
Shen, Zuo-Jun Max
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:46-532010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:46-53
article
Hybrid variable neighbourhood approaches to university exam timetabling
In this paper, we investigate variable neighbourhood search (VNS) approaches for the university examination timetabling problem. In addition to a basic VNS method, we introduce variants of the technique with different initialisation methods including a biased VNS and its hybridisation with a Genetic Algorithm. A number of different neighbourhood structures are analysed. It is demonstrated that the proposed technique is able to produce high quality solutions across a wide range of benchmark problem instances. In particular, we demonstrate that the Genetic Algorithm, which intelligently selects appropriate neighbourhoods to use within the biased VNS, produces the best known results in the literature, in terms of solution quality, on some of the benchmark instances. However, it requires relatively large amount of computational time. Possible extensions to this overall approach are also discussed.
Examination timetabling Meta-heuristics Variable neighbourhood search Genetic Algorithms
http://www.sciencedirect.com/science/article/B6VCT-4Y9CF8M-4/2/65c03a24a5e218fb75a04adda440b1cd
Burke, E.K.
Eckersley, A.J.
McCollum, B.
Petrovic, S.
Qu, R.
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:350-3602010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:350-360
article
The multi-product newsboy problem with supplier quantity discounts and a budget constraint
This paper considers the multi-product newsboy problem with both supplier quantity discounts and a budget constraint, while each feature has been addressed separately in the literature. Different from most previous nonlinear optimization models on the topic, the problem is formulated as a mixed integer nonlinear programming model due to price discounts. A Lagrangian relaxation approach is presented to solve the problem. Computational results on both small and large-scale test instances indicate that the proposed algorithm is extremely effective for the problem. An extension to multiple constraints and preliminary computational results are also reported.
Inventory Newsboy model Quantity discount Budget constraint Lagrangian relaxation Mixed integer nonlinear programming
http://www.sciencedirect.com/science/article/B6VCT-4YJ4N9T-2/2/a1f89de7d959947744e60d6f2d66b9bf
Zhang, Guoqing
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:168-1772010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:168-177
article
A branch and bound algorithm for determining locations of long-term care facilities
This paper focuses on the problem of determining locations for long-term care facilities with the objective of balancing the numbers of patients assigned to the facilities. We present a branch and bound algorithm by developing dominance properties, a lower bounding scheme and a heuristic algorithm for obtaining an upper bound for the problem. For evaluation of the suggested branch and bound algorithm, computational experiments are performed on a number of test problems. Results of the experiments show that the suggested algorithm gives optimal solutions of problems of practical sizes in a reasonable amount of computation time.
Facility location problem Long-term care facility Branch and bound
http://www.sciencedirect.com/science/article/B6VCT-4YF5R5J-1/2/a13cb3322acfb7c3519ddb1adc97773e
Kim, Dong-Guen
Kim, Yeong-Dae
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:557-5702010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:557-570
article
Semiconductor lot allocation using robust optimization
In this work, the problem of allocating a set of production lots to satisfy customer orders is considered. This research is of relevance to lot-to-order matching problems in semiconductor supply chain settings. We consider that lot-splitting is not allowed during the allocation process due to standard practices. Furthermore, lot-sizes are regarded as uncertain planning data when making the allocation decisions due to potential yield loss. In order to minimize the total penalties of demand un-fulfillment and over-fulfillment, a robust mixed-integer optimization approach is adopted to model is proposed the problem of allocating a set of work-in-process lots to customer orders, where lot-sizes are modeled using ellipsoidal uncertainty sets. To solve the optimization problem efficiently we apply the techniques of branch-and-price and Benders decomposition. The advantages of our model are that it can represent uncertainty in a straightforward manner with little distributional assumptions, and it can produce solutions that effectively hedge against the uncertainty in the lot-sizes using very reasonable amounts of computational effort.
Semiconductor supply chain Lot assignment Uncertainty modeling Robust optimization Generalized Benders Branch-and-price
http://www.sciencedirect.com/science/article/B6VCT-4Y6S7KM-1/2/9c601f3477c7d4e0149a0f0754dbec84
Ng, Tsan Sheng
Sun, Yang
Fowler, John
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:144-1542010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:144-154
article
Constrained group balancing: Why does it work
We consider a problem where a set of objects possessing multiple attributes must be partitioned into a certain number of groups so that the groups are as balanced as possible with respect to the number of objects possessing each attribute. This multi-criteria decision problem arises in a variety of practical applications, ranging from assigning students to study groups to designing level schedules for JIT assembly lines. A direct approach, enforcing balance through hard constraints, may lead to infeasibility, but works well in practice. We analyze this phenomenon from the worst-case and empirical perspectives, as well as through an in-depth analysis of one representative practical application - the design of student groups at the Rotman School of Management, University of Toronto. The goals of the analysis are to understand what classes of balancing problems may contain infeasible instances and how prevalent such instances are within these classes, as well as to synthesize practical managerial insights that a decision maker could follow in order to increase the chances that balanced groups can be found.
Decision support Combinatorial optimization OR applications - education Group balancing
http://www.sciencedirect.com/science/article/B6VCT-4YCS00V-2/2/68f5975d60b388ce43f5315e2159a213
Krass, Dmitry
Ovchinnikov, Anton
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:34-452010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:34-45
article
Global convergence of a robust filter SQP algorithm
We present a robust filter SQP algorithm for solving constrained optimization problems. This algorithm is based on the modified quadratic programming proposed by Burke to avoid the infeasibility of the quadratic programming subproblem at each iteration. Compared with other filter SQP algorithms, our algorithm does not require any restoration phase procedure which may spend a large amount of computation. The main advantage of our algorithm is that it is globally convergent without requiring strong constraint qualifications, such as Mangasarian-Fromovitz constraint qualification (MFCQ) and the constant rank constraint qualification (CRCQ). Furthermore, the feasible limit points of the sequence generated by our algorithm are proven to be the KKT points if some weaker conditions are satisfied. Numerical results are also presented to show the efficiency of the algorithm.
Filter SQP Constrained optimization CPLD
http://www.sciencedirect.com/science/article/B6VCT-4YH569R-2/2/675e0ce69a72d6eefb8aa49e2eec245b
Shen, Chungen
Xue, Wenjuan
Chen, Xiongda
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:341-3492010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:341-349
article
A branch-and-price algorithm for the Vehicle Routing Problem with Deliveries, Selective Pickups and Time Windows
In the Vehicle Routing Problem with Deliveries, Selective Pickups and Time Windows, the set of customers is the union of delivery customers and pickup customers. A fleet of identical capacitated vehicles based at the depot must perform all deliveries and profitable pickups while respecting time windows. The objective is to minimize routing costs, minus the revenue associated with the pickups. Five variants of the problem are considered according to the order imposed on deliveries and pickups. An exact branch-and-price algorithm is developed for the problem. Computational results are reported for instances containing up to 100 customers.
Transportation Vehicle routing Deliveries and selective pickups Time windows Branch-and-price Shortest paths with resources
http://www.sciencedirect.com/science/article/B6VCT-4YJ4N9T-5/2/f0b31114a161f346054825624ff901f2
Gutiérrez-Jarpa, Gabriel
Desaulniers, Guy
Laporte, Gilbert
Marianov, Vladimir
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:197-2082010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:197-208
article
On pricing of multiple bundles of products and services
This paper considers the pricing decision faced by a seller of bundles composed of a service and an associated product offered to customers on a subscription basis using a two-part tariff scheme. An optimal pricing policy that maximizes the profit of a firm is obtained using a dynamic programming approach and it is found that, in the long run, there is an optimal number of customers associated to each bundle. Due to managerial purposes, two suboptimal fixed-price policies are derived and compared to the optimal pricing policy. The conditions under which it is profitable for the firm to expand its offer from one to two bundles is studied. Finally, it is concluded that introducing a fee for subscribed customers to deter the switching from one bundle to the other, increases the profitability of the firm.
Pricing Bundling Two-part tariff Consumer choice
http://www.sciencedirect.com/science/article/B6VCT-4YC2XF9-1/2/fd85e23d64fb319d61b3f356378a1b4c
Ferrer, Juan-Carlos
Mora, Hugo
Olivares, Francisco
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:528-5392010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:528-539
article
A discrete particle swarm optimization method for feature selection in binary classification problems
This paper investigates the feature subset selection problem for the binary classification problem using logistic regression model. We developed a modified discrete particle swarm optimization (PSO) algorithm for the feature subset selection problem. This approach embodies an adaptive feature selection procedure which dynamically accounts for the relevance and dependence of the features included the feature subset. We compare the proposed methodology with the tabu search and scatter search algorithms using publicly available datasets. The results show that the proposed discrete PSO algorithm is competitive in terms of both classification accuracy and computational performance.
Feature selection Particle swarm optimization Metaheuristics Binary classification Logistic regression
http://www.sciencedirect.com/science/article/B6VCT-4YG7JVK-2/2/0f7c10ac657ab812b36cd7a73839cc3d
Unler, Alper
Murat, Alper
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:111-1172010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:111-117
article
Burn-in by environmental shocks for two ordered subpopulations
Burn-in is a widely used engineering method of elimination of defective items before they are shipped to customers or put into field operation. In conventional burn-in procedures, components or systems are subject to a period of simulated operation prior to actual usage. Then those which failed during this period are scrapped and discarded. In this paper, we assume that the population of items is composed of two ordered subpopulations and the elimination of weak items by using environmental shocks is considered. Optimal severity levels of these shocks that minimize the defined expected costs are investigated. Some illustrative examples are discussed.
Reliability Burn-in Shocks Heterogeneous populations Optimal severity
http://www.sciencedirect.com/science/article/B6VCT-4YDC3M5-1/2/b6c0a43aa1a2a564eff673fb62903500
Cha, Ji Hwan
Finkelstein, Maxim
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:496-5072010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:496-507
article
Asymptotic revenue equivalence of asymmetric auctions with interdependent values
We prove an asymptotic revenue equivalence among weakly asymmetric auctions with interdependent values, in which bidders have either asymmetric utility functions or asymmetric distributions of signals.
Asymmetric auctions Interdependent values Perturbation analysis Revenue equivalence
http://www.sciencedirect.com/science/article/B6VCT-4YMB64R-1/2/c5a304f72f47cf897158d069c397dc48
Fibich, Gadi
Gavious, Arieh
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:178-1962010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:178-196
article
An incentive-compatible solution for trade credit term incorporating default risk
This paper studies the optimal trade credit term decision in an extended economic ordering quantity (EOQ) framework that incorporates a default risk component. A principal-agent bilevel programming model with costs minimization objectives is set up to derive the incentive-compatible credit term. The supplier determines the credit term as the leader in the first level programming, by balancing her/his financing capacity with the retailer's default risk, order behavior and cost shifting. At the second level, the retailer makes decisions on ordering and payment time by reacting on the term offered by the supplier. A first order condition solution procedure is derived for the bilevel programming when credit term is confined within the practically feasible interval. Two key results are obtained - the condition to derive incentive-compatible credit term, and an equation system to derive threshold default risk criterion filtering retailers suitable for credit granting. Numerical experiments show that the capital cost of the supplier is the most important factor determining the credit term. Default risk acts like a filtering criterion for selecting retailers suitable for credit granting. Empirical evidence supporting our theoretical considerations is obtained by estimating three panel econometric models, using a dataset from China's listed companies.
Trade credit Credit term Bilevel programming Default risk EOQ
http://www.sciencedirect.com/science/article/B6VCT-4YB78X0-2/2/7d004ed4da5f172a47926a3b367e750e
Shi, Xiaojun
Zhang, Shunming
oai:RePEc:eee:ejores:v:206:y:2010:i:2:p:301-3122010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:2:p:301-312
article
A unified approach for scheduling with convex resource consumption functions using positional penalties
We provide a unified model for solving single machine scheduling problems with controllable processing times in polynomial time using positional penalties. We show how this unified model can be useful in solving three different groups of scheduling problems. The first group includes four different due date assignment problems to minimize an objective function which includes costs for earliness, tardiness, due date assignment, makespan and total resource consumption. The second group includes three different due date assignment problems to minimize an objective function which includes the weighted number of tardy jobs, due date assignment costs, makespan and total resource consumption costs. The third group includes various scheduling problems which do not involve due date assignment decisions. We show that each of the problems from the first and the third groups can be reduced to a special case of our unified model and thus can be solved in O(n3) time. Furthermore, we show how the unified model can be used repeatedly as a subroutine to solve all problems from the second group in O(n4) time. In addition, we also show that faster algorithms exist for several special cases.
Single machine scheduling Controllable processing times Resource allocation Due date assignment Positional penalties Polynomial-time algorithm
http://www.sciencedirect.com/science/article/B6VCT-4YFCF7D-4/2/9f3a268975bf263ce40f6f7ff5342ef4
Leyvand, Yaron
Shabtay, Dvir
Steiner, George
oai:RePEc:eee:ejores:v:87:y:1995:i:3:p:iii-(null)2010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:87:y:1995:i:3:p:iii-(null)
article
Preface from the president of IFORS
http://www.sciencedirect.com/science/article/B6VCT-486T5FS-3/2/1736596918e80f3b27525939927c2c56
Bell, Peter
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:667-6752010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:667-675
article
The selection efficiency of tournaments
We discuss tournaments in terms of their efficiency as probabilistic mechanisms that select high-quality alternatives ("players") in a noisy environment. We characterize the selection efficiency of three such mechanisms - contests, binary elimination tournaments, and round-robin tournaments - depending on the shape of the distribution of players' quality, the number of players, and noise level. The results have implications as to how, and under what circumstances, the efficiency of tournament-based selection can be manipulated.
Human resources Applied probability Selection Tournament Simulation
http://www.sciencedirect.com/science/article/B6VCT-4YM7K8V-2/2/c4e3a8faf9ebdc3c3a4a1d1224879ec0
Ryvkin, Dmitry
oai:RePEc:eee:ejores:v:205:y:2010:i:3:p:625-6372010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:205:y:2010:i:3:p:625-637
article
A dynamic bounding algorithm for approximating multi-state two-terminal reliability
This paper modifies Jane and Laih's (2008) exact and direct algorithm to provide sequences of upper bounds and lower bounds that converge to the NP-hard multi-state two-terminal reliability. Advantages of the modified algorithm include (1) it does not require a priori the lower and/or upper boundary points of the network, (2) it derives a series of increasing lower bounds and a series of decreasing upper bounds simultaneously, guaranteed to enclose the exact reliability value, and (3) trade-off between accuracy and execution time can be made to ensure an exact difference between the upper and lower bounds within an acceptable time. Examples are analyzed to illustrate the bounding algorithm, and to compare the bounding algorithm with existing algorithms. Computational experiments on a large network are conducted to realize the performance of the bounding algorithm.
Reliability Multi-state network Network flow Upper/lower bounds
http://www.sciencedirect.com/science/article/B6VCT-4Y7P6VC-3/2/61d1acdf3bcbe3061cdfd3ab985f5fe3
Jane, Chin-Chia
Laih, Yih-Wenn
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:86-922010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:86-92
article
The setting of profit targets for target oriented divisions
Setting profit targets and striving to achieve them is fundamental to business survival and success. However, there has been little research on modeling profit-target setting. In this paper, we study analytic target setting under a common business scenario where a firm is in control of multiple divisions. Both the firm and the divisions maximize the profit probability, i.e., the probability of achieving some given profit target. The firm sets a profit target for each division which then acts as a price-setting newsvendor. We first obtain the optimal order quantity, the optimal retail price, and the maximal profit probability of a single division given its assigned target. We then derive the firm's profit probability and focus on two specific cases to gain more managerial insights. In the first case of fair target setting, we show that when each division's demand distribution has an increasing failure rate, if a division has a relatively high (low) production cost, its assigned profit target decreases (increases) with regard to its price elasticity. In the second case, if the firm is in control of two identical divisions, each division's optimal profit target is just half of the firm's profit target when the price elasticity is two or more, regardless of production cost and demand distribution.
Target setting Newsvendor Pricing Risk-aversion
http://www.sciencedirect.com/science/article/B6VCT-4YC1K3P-2/2/c1b15dbed2223a583af5dcde752d2f9b
Shi, Chunming Victor
Zhao, Xuan
Xia, Yu
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:64-722010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:64-72
article
Accelerated tabu search for no-wait flowshop scheduling problem with maximum lateness criterion
For the no-wait flowshop scheduling problem with maximum lateness criterion, properties are developed to speed up three kinds of basic operations generating candidate solutions, i.e., the insertion of a new job into a partial sequence, and the insertion and exchange neighborhood moves. The properties reduce the time to evaluate a candidate from O(nm) to O(1) and simplify the implementation of the heuristics based on the basic operations by evaluating candidates before their generation. The properties also reduce from O(n3m) to O(n2) the time complexity of well-known NEH heuristic and the complete evaluation of the insertion and exchange neighborhoods. Tabu search (TS) is applied to the considered problem, since TS tries to find the best neighbor of the current solution in each iteration and therefore can much benefit from the speedups. Three different ways to use insertion and exchange neighborhoods are compared in TS. Computational experiments show that the speedups are more helpful as job number increases and all proposed TS algorithms are more effective and robust than the existing algorithms. Although two- and single-neighborhood TS algorithms are not significantly different, two-neighborhood TS algorithms are more preferable.
Scheduling No-wait flowshop Maximum lateness Tabu search Neighborhood
http://www.sciencedirect.com/science/article/B6VCT-4YHNYXM-1/2/93722ac2ee21203fb6caf033cfe6591d
Wang, Chuyang
Li, Xiaoping
Wang, Qian
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:562-5682010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:562-568
article
An exact algorithm for minimizing resource availability costs in project scheduling
A new exact algorithm that solves the Resource Availability Cost Problem (RACP) in project scheduling is shown to yield a significant improvement over the existing algorithm in the literature. The new algorithm consists of a hybrid method where an initial feasible solution is found heuristically. The branching scheme solves a Resource-Constrained Project Scheduling Problem (RCPSP) at each node where the resources of the RACP are fixed. The knowledge of previously solved RCPSPs is used to produce cuts in the search tree. A worst-case-performance theorem is established for this new algorithm. Experiments are performed on instances adapted from the PSPLIB database. The new algorithm can be used to minimize any resource availability cost problem once a procedure for the underlying resource-constrained problem is available.
Project scheduling Resource availability Exact algorithm
http://www.sciencedirect.com/science/article/B6VCT-4YJCKSY-5/2/076f20c5322d2edb149aedd8f1ee68d5
Rodrigues, Sávio B.
Yamashita, Denise S.
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:18-332010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:18-33
article
Natural gas cash-out problem: Bilevel stochastic optimization approach
A stochastic formulation of the natural gas cash-out problem is given in a form of a bilevel multi-stage stochastic programming model with recourse. After reducing the original formulation to a bilevel linear problem, a stochastic scenario tree is defined by its node events, and time series forecasting is used to produce stochastic values for data of natural gas price and demand. Numerical experiments were run to compare the stochastic solution with the perfect information solution and the expected value solutions.
Natural gas imbalance problem Time series Stochastic programming
http://www.sciencedirect.com/science/article/B6VCT-4YDYSGF-2/2/dee4f3bcb1b0c05b94acbe6508c1aa37
Kalashnikov, Vyacheslav V.
Pérez-Valdés, Gerardo A.
Tomasgard, Asgeir
Kalashnykova, Nataliya I.
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:522-5272010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:522-527
article
A mixed integer linear programming formulation of the maximum betweenness problem
This paper considers the maximum betweenness problem. A new mixed integer linear programming (MILP) formulation is presented and validity of this formulation is given. Experimental results are performed on randomly generated instances from the literature. The results of CPLEX solver, based on the proposed MILP formulation, are compared with results obtained by total enumeration technique. The results show that CPLEX optimally solves instances of up to 30 elements and 60 triples in a short period of time.
Integer programming Linear programming Betweenness problem
http://www.sciencedirect.com/science/article/B6VCT-4YG7JVK-1/2/b2a9f44849b275ac883ccd4be9fc82ba
Savic, Aleksandar
Kratica, Jozef
Milanovic, Marija
Dugosija, Djordje
oai:RePEc:eee:ejores:v:206:y:2010:i:1:p:248-2592010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:1:p:248-259
article
On the robustness of non-linear personalized price combinatorial auctions
Though the VCG auction assumes a central place in the mechanism design literature, there are a number of reasons for favoring Iterative Combinatorial Auctions (ICAs). Several promising ICA formats were developed based on primal-dual and subgradient algorithms. Prices are interpreted as a feasible dual solution and the provisional allocation is interpreted as a feasible primal solution. iBundle(3), dVSV and Ascending Proxy Auction result in VCG payoffs when the coalitional value function satisfies buyer submodularity and bidders bid straightforward, which is an ex-post Nash equilibrium in this case. iBEA and CreditDebit auctions do not even require the buyer submodularity and achieve the same properties for general valuations. Often, however, one cannot assume straightforward bidding and it is not clear from the theory how these non-linear personalized price auctions (NLPPAs) perform in this case. Robustness of auctions with respect to different bidding behavior is a critical issue for any application. We conducted a large number of computational experiments to analyze the performance of NLPPAs with respect to different bidding strategies and valuation models. We compare NLPPAs with the VCG auction and with ICAs with linear prices, such as ALPS and the Combinatorial Clock Auction. While NLPPAs performed very well in case of straightforward bidding, we observe problems with revenue, efficiency, and speed of convergence when bidders deviate.
Combinatorial auction Primal-dual auction Subgradient auction Allocative efficiency Computational experiment Simulation
http://www.sciencedirect.com/science/article/B6VCT-4YB78X0-1/2/36f8484b5183a86e3da6321b4e03f106
Schneider, S.
Shabalin, P.
Bichler, M.
oai:RePEc:eee:ejores:v:206:y:2010:i:3:p:702-7022010-07-08RePEc:eee:ejores
RePEc:eee:ejores:v:206:y:2010:i:3:p:702-702
article
Directional distance functions and slacks-based measures of efficiency: Some clarifications
This note clarifies issues concerning the relationship between directional distance functions and slacks-based measures of efficiency from our earlier paper.
SBM Directional distance functions DEA Linear programming
http://www.sciencedirect.com/science/article/B6VCT-4YH569R-3/2/cf9e0f0e0ad14f348ed4e4a32dded21a
Färe, Rolf
Grosskopf, Shawna
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:412-4342009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:412-434
article
Valid inequalities for the single-item capacitated lot sizing problem with step-wise costs
This paper presents a new class of valid inequalities for the single-item capacitated lot sizing problem with step-wise production costs (LS-SW). Constant sized batch production is carried out with a limited production capacity in order to satisfy the customer demand over a finite horizon. A new class of valid inequalities we call mixed flow cover, is derived from the existing integer flow cover inequalities by a lifting procedure. The lifting coefficients are sequence independent when the batch sizes (V) and the production capacities (P) are constant and when V divides P. When the restriction of the divisibility is removed, the lifting coefficients are shown to be sequence independent. We identify some cases where the mixed flow cover inequalities are facet defining. We propose a cutting plane algorithm for different classes of valid inequalities introduced in the paper. The exact separation algorithm proposed for the constant capacitated case runs in polynomial time. Computational results show the efficiency of the new class mixed flow cover compared to the existing methods.
Integer programming Single-item capacitated lot sizing problem Flow cover inequalities Cutting plane algorithm
http://www.sciencedirect.com/science/article/B6VCT-4TKPVC6-1/2/10c3f322cdf6d68d7eb96ecdca69fc7c
Akbalik, A.
Pochet, Y.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:922-9352009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:922-935
article
Robust multi-echelon multi-period inventory control
We consider the problem of minimizing the overall cost of a supply chain, over a possible long horizon, under demand uncertainly which is known only crudely. Under such circumstances, the method of choice is Robust Optimization, in particular the Affinely Adjustable Robust Counterpart (AARC) method which leads to tractable deterministic optimization problems. The latter is due to a recent re-parametrization technique for discrete time linear control systems. In this paper we model, analyze and test an extension of the AARC method known as the Globalized Robust Counterpart (GRC) in order to control inventories in serial supply chains. A simulation study demonstrates the merit of the methods employed here, in particular, it shows that a good control law that minimizes cost achieves simultaneously good control of the bullwhip effect.
Multi-echelon supply chains Multi-period inventory control Robust Optimization Affinely adjustable robust optimization Globalized Robust Counterpart Bullwhip effect
http://www.sciencedirect.com/science/article/B6VCT-4VYP94C-6/2/ed614292189650a686b1873c33954b89
Aharon, Ben-Tal
Boaz, Golany
Shimrit, Shtern
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:504-5102009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:504-510
article
Replenishment decisions under an all-units discount schedule and stepwise freight costs
In this study, we analyze the replenishment decisions under a general replenishment cost structure that includes stepwise freight costs and all-units quantity discounts. We first formulate a general model that accounts for a larger class of problems and prove several useful properties of the expected profit function. We later utilize these properties to develop a computational solution approach to find the optimal order quantity. As an application of the general results, we study the replenishment decisions in the single-period, i.e., the Newsboy, problem considering several scenarios that model the cost considerations either for the buyer or for both the buyer and the vendor.
All-units discount Transportation Cargo capacity Newsboy model/problem
http://www.sciencedirect.com/science/article/B6VCT-4TN0KW2-2/2/d2f98833f9a0a1dee69e417e8781d605
Toptal, Aysegül
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:405-4112009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:405-411
article
A Lagrangian relaxation approach to large-scale flow interception problems
The paper presents a tight Lagrangian bound and an efficient dual heuristic for the flow interception problem. The proposed Lagrangian relaxation decomposes the problem into two subproblems that are easy to solve. Information from one of the subproblems is used within a dual heuristic to construct feasible solutions and is used to generate valid cuts that strengthen the relaxation. Both the heuristic and the relaxation are integrated into a cutting plane method where the Lagrangian bound is calculated using a subgradient algorithm. In the course of the algorithm, a valid cut is added and integrated efficiently in the second subproblem and is updated whenever the heuristic solution improves. The algorithm is tested on randomly generated test problems with up to 500 vertices, 12,483 paths, and 43 facilities. The algorithm finds a proven optimal solution in more than 75% of the cases, while the feasible solution is on average within 0.06% from the upper bound.
Flow interception problem Lagrangian relaxation Subgradient optimization Cutting planes Dual heuristic
http://www.sciencedirect.com/science/article/B6VCT-4TF2J2P-1/2/473107fdbc226cb61791d792c2df046e
Gzara, Fatma
Erkut, Erhan
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:626-6362009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:626-636
article
Rough set approach to multiple criteria classification with imprecise evaluations and assignments
Dominance-based Rough Set Approach (DRSA) has been introduced to deal with multiple criteria classification (also called multiple criteria sorting, or ordinal classification with monotonicity constraints), where assignments of objects may be inconsistent with respect to dominance principle. In this paper, we consider an extension of DRSA to the context of imprecise evaluations of objects on condition criteria and imprecise assignments of objects to decision classes. The imprecisions are given in the form of intervals of possible values. In order to solve the problem, we reformulate the dominance principle and introduce second-order rough approximations. The presented methodology preserves well-known properties of rough approximations, such as rough inclusion, complementarity, identity of boundaries and precisiation. Moreover, the meaning of the precisiation property is extended to the considered case. The paper presents also a way to reduce decision tables and to induce decision rules from rough approximations.
Dominance-based rough set approach Multiple criteria decision analysis Multiple criteria classification Ordinal classification Monotonicity constraints Decision rules Imprecise information Interval order
http://www.sciencedirect.com/science/article/B6VCT-4TN82H3-1/2/3af9ee20c41381b053b1357834150603
Dembczynski, Krzysztof
Greco, Salvatore
Slowinski, Roman
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:285-2952009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:285-295
article
Numerical calculation of an asymmetric supply function equilibrium with capacity constraints
Producers submit offer curves to a procurement auction, e.g. an electricity auction, before uncertain demand has been realised. In the supply function equilibrium (SFE), every firm commits to the offer curve that maximises its expected profit, given the offer curves of competitors. The equilibrium is given by a system of differential equations. In practice, it has been very difficult to find valid SFE, i.e. non-decreasing solutions, from this system, especially for asymmetric producers. This paper shows that valid SFE can be calculated by means of a shooting algorithm that combines numerical integration with an optimisation procedure that searches for an end-condition. Multiple/parallel shooting is used for ill-conditioned cases.
Auctions/bidding Game theory OR in energy Supply function equilibrium Numerical integration Shooting
http://www.sciencedirect.com/science/article/B6VCT-4TW1348-2/2/5032b0c658bf9b1e0392888caf23296d
Holmberg, Pär
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:219-2312009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:219-231
article
A decision support framework for internal audit prioritization in a rental car company: A combined use between DEA and AHP
Corporate scandals such as those at Tyco, Enron, and WorldCom have caused the decline of public trust in accounting and reporting practices. In response, US passed the Sarbanes Oxley Law (Sarbanes) in 2002, the most important corporate governance law since securities laws in 1930s. Section 302 of Sarbanes mandates corporations to ensure accurate financial disclosure and to take greater financial reporting and control responsibilities. Management is required to make an annual assertion regarding the design and effectiveness of company's internal controls. Consequently, many internal auditing resources are stretched. The objective of this case study is to develop a multi-criteria decision making aid that can identify the most critical businesses units within a corporation. Using the aid, we can use efficiently and effectively the internal auditing resources. Internal audits determine if the accounting processes and systems are working as intended. It focuses on the reliability of the accounting data and evaluates business through financial, operational, and compliance review. It assesses the risk of asset loss, studies business processes, and identifies opportunities to improve efficiency and effectiveness. This study explores the potential of applying data envelopment analysis (DEA) and analytic hierarchy process (AHP) to determine the business units that need audit. Compared with conventional methods, the proposed combined model incorporates a much wider range of quantitative and qualitative criteria, and provides a more detailed and thorough study. The proposed evaluation framework is comprehensive and flexible and it shows great potential for internal audit prioritization and resource allocation.
Auditing Data envelopment analysis Analytic hierarchy process Multiple criteria analysis Competitiveness
http://www.sciencedirect.com/science/article/B6VCT-4TYJTYS-4/2/8152ca53571fa4efae3f14ee1b0f8022
Sueyoshi, Toshiyuki
Shang, Jennifer
Chiang, Wen-Chyuan
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:198-2082009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:198-208
article
Resource-constrained management of heterogeneous assets with stochastic deterioration
We consider a collection of heterogeneous assets which exhibit independent stochastic behavior, but are economically interdependent due to resource constraints on management decisions. We represent the collection of assets as a network of nonhomogeneous Markov decision processes linked by side constraints. To facilitate a procedure for obtaining nonrandomized decision policies, we express the resource limitations as integrated chance constraints and relax them into the objective function within a Lagrangian penalty term. We utilize subgradient optimization to establish upper bounds and a greedy randomized Lagrangian repair heuristic to obtain feasible solutions. We empirically validate the tightness of these a posteriori upper and lower bounds with computational experiments on a pair of applications. For pavement maintenance, we examine the effect that the reward structure of each constituent MDP has on the maintenance policy in the presence of budget constraints. For equipment replacement, we consider constraints on two resource types.
Nonhomogeneous Markov decision processes Lagrangian relaxation Heuristic Pavement maintenance Equipment replacement
http://www.sciencedirect.com/science/article/B6VCT-4TXF7XP-3/2/74c9f28af948aaafee4c5d36e53f3d2a
Ohlmann, Jeffrey W.
Bean, James C.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:46-542009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:46-54
article
Activity list representation for a generalization of the resource-constrained project scheduling problem
Most of the real life scheduling problems include several constraints in addition to the precedence and resource constraints considered in the resource-constrained project scheduling problem (RCPSP). In this paper, we define a generalization of the (RCPSP) with a wide class of additional constraints, including (but not limited to): a pair of activities must be separated by at least a given duration; a subset of activities cannot be processed simultaneously; an activity cannot start before a particular period; an activity cannot be scheduled in a particular time window; there are resource constraints with varying required and available quantities. We show that for this generalization the activity list and the activity set list representations can be used as efficiently as in the (RCPSP) and that by using these representations the optimal solution can always be reached. This allows most of the known solution procedures for (RCPSP) based on these representations to be extended for the generalized (RCPSP) by simply replacing the classical decoding procedure used for the (RCPSP) with the generalized version introduced here.
Project scheduling Resource-constrained project scheduling Generalized resource-constrained project scheduling Activity list Activity set list
http://www.sciencedirect.com/science/article/B6VCT-4TW6HR9-3/2/ff4b73d4ee7f633e04ba2ebaecb806d6
Moumene, Khaled
Ferland, Jacques A.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:1-82009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:1-8
article
Branch-and-reduce algorithm for convex programs with additional multiplicative constraints
This article presents a branch-and-reduce algorithm for globally solving for the first time a convex minimization problem (P) with p[greater-or-equal, slanted]1 additional multiplicative constraints. In each of these p additional constraints, the product of two convex functions is constrained to be less than or equal to a positive number. The algorithm works by globally solving a 2p-dimensional master problem (MP) equivalent to problem (P). During a typical stage k of the algorithm, a point is found that minimizes the objective function of problem (MP) over a nonconvex set Fk that contains the portion of the boundary of the feasible region of the problem where a global optimal solution lies. If this point is feasible in problem (MP), the algorithm terminates. Otherwise, the algorithm continues by branching and creating a new, reduced nonconvex set Fk+1 that is a strict subset of Fk. To implement the algorithm, all that is required is the ability to solve standard convex programming problems and to implement simple algebraic steps. Convergence properties of the algorithm are given, and results of some computational experiments are reported.
Global optimization Multiplicative programming Product of convex functions Branch-and-reduce
http://www.sciencedirect.com/science/article/B6VCT-4TW6HR9-1/2/d2f6d1bad6a1c8b0e6a2cb7f24801bf1
Benson, Harold P.
Sun, Erjiang
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:892-9012009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:892-901
article
Expected utility versus the changes in knowledge ahead
We present a decision theory appropriate for use in serious choices such as insurance. It extends standard decision theories like expected utility or cumulative prospect theory which are atemporal single stage theories. Instead it employs stages of knowledge ahead to track satisfactions and dissatisfactions. In the first stage of the risk, the uninsured face dissatisfactions of worries and planning difficulties (avoided by the insured), also perhaps positive satisfactions of thrills (missed out by the insured). In the second stage when the risk is past, the uninsured may face the dissatisfactions of ridicule and blame if they learn that they were unlucky. From experimental and questionnaire data, 80% of our subjects are influenced by such secondary satisfactions. Only five percent of our participants employ the usage of integrated quantitative aggregation rules for evaluating acts as assumed under expected utility theory.
Primary and secondary satisfactions Risk Decision making Decision analysis Experimental economics Heuristics Stages of knowledge ahead theory
http://www.sciencedirect.com/science/article/B6VCT-4VYP94C-4/2/b98ed45a08fdf49a2edb4acacb28ab12
Pope, Robin
Leitner, Johannes
Leopold-Wildburger, Ulrike
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:943-9572009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:943-957
article
A shift scheduling model for employees with different seniority levels and an application in healthcare
This paper addresses the problem of scheduling medical residents that arises in different clinical settings of a hospital. The residents are grouped according to different seniority levels that are specified by the number of years spent in residency training. It is required from the residents to participate in the delivery of patient care services directly by working weekday and weekend day shifts in addition to their regular daytime work. A monthly shift schedule is prepared to determine the shift duties of each resident considering shift coverage requirements, seniority-based workload rules, and resident work preferences. Due to the large number of constraints often conflicting, a multi-objective programming model has been proposed to automate the schedule generation process. The model is implemented on a real case in the pulmonary unit of a local hospital for a 6-month period using sequential and weighted methods. The results indicate that high quality solutions can be obtained within a few seconds compared to the manually prepared schedules expending considerable effort and time. It is also shown that the employed weighting procedure based on seniority levels performs much better compared to the preemptive method in terms of computational burden.
OR in manpower planning OR in health services Multiple objective programming Shift scheduling Resident physicians Seniority
http://www.sciencedirect.com/science/article/B6VCT-4TWV6MD-1/2/0876c76a0f88b8ff61016bdd2c9ceb09
Topaloglu, Seyda
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:77-882009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:77-88
article
Multi-degree cyclic scheduling of a no-wait robotic cell with multiple robots
This paper addresses cyclic scheduling of a no-wait robotic cell with multiple robots. In contrast to many previous studies, we consider r-degree cyclic (rÂ >Â 1) schedules, in which r identical parts with constant processing times enter and leave the cell in each cycle. We propose an algorithm to find the minimal number of robots for all feasible r-degree cycle times for a given r (rÂ >Â 1). Consequently, the optimal r-degree cycle time for any given number of robots for this given r can be obtained with the algorithm. To develop the algorithm, we first show that if the entering times of r parts, relative to the start of a cycle, and the cycle time are fixed, minimizing the number of robots for the corresponding r-degree schedule can be transformed into an assignment problem. We then demonstrate that the cost matrix for the assignment problem changes only at some special values of the cycle time and the part entering times, and identify all special values for them. We solve our problem by enumerating all possible cost matrices for the assignment problem, which is subsequently accomplished by enumerating intervals for the cycle time and linear functions of the part entering times due to the identification of the special values. The algorithm developed is shown to be polynomial in the number of machines for a fixed r, but exponential if r is arbitrary.
Cyclic scheduling No-wait Robotic cells Cycle time
http://www.sciencedirect.com/science/article/B6VCT-4TY459J-1/2/4c884cb67d0f955ed98d5b5b7a41acd9
Che, Ada
Chu, Chengbin
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:303-3102009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:303-310
article
How to generate regularly behaved production data? A Monte Carlo experimentation on DEA scale efficiency measurement
Monte Carlo experimentation is a well-known approach used to test the performance of alternative methodologies under different hypotheses. In the frontier analysis framework, whatever the parametric or non-parametric methods tested, experiments to date have been developed assuming single output multi-input production functions. The data generated have mostly assumed a Cobb-Douglas technology. Among other drawbacks, this simple framework does not allow the evaluation of DEA performance on scale efficiency measurement. The aim of this paper is twofold. On the one hand, we show how reliable two-output two-input production data can be generated using a parametric output distance function approach. A variable returns to scale translog technology satisfying regularity conditions is used for this purpose. On the other hand, we evaluate the accuracy of DEA technical and scale efficiency measurement when sample size and output ratios vary. Our Monte Carlo experiment shows that the correlation between true and estimated scale efficiency is dramatically low when DEA analysis is performed with small samples and wide output ratio variations.
Parametric distance function DEA Technical efficiency Scale efficiency Monte Carlo experiments
http://www.sciencedirect.com/science/article/B6VCT-4V0TD2N-5/2/77d22693784288287f77f66fd3e07b1b
Perelman, Sergio
Santín, Daniel
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:9-202009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:9-20
article
Interval goal programming for S-shaped penalty function
The approach of Jones and Tamiz (1995) [Jones, D.F., Tamiz, M., 1995. Expanding the flexibility of goal programming via preference modeling techniques. Omega 23, 41-48] has been accepted as the most efficient approach in the field of interval goal programming (IGP). Although several modifications to the original approach have been proposed recently [Vitoriano, B., Romero, C., 1999. Extended interval goal programming. Journal of the Operational Research Society 50, 1280-1283; Chang, C.-T., 2006. Mixed binary interval goal programming. Journal of the Operational Research Society 35, 389-396], all of them cannot formulate IGP with an S-shaped penalty function. In order to improve the utility of IGP, we extend the model of Chang (2006) [Chang, C.-T., 2006. Mixed binary interval goal programming. Journal of the Operational Research Society 35, 389-396] to be able to model an S-shaped penalty function. The newly formulated model is more concise and compact than the method of Li and Yu (2000) and it can easily be applied to a decision problem with the S-shaped penalty function. Finally, an illustrative example (i.e. how to build an appropriate E-learning system) is included for demonstrating the usefulness of the proposed model.
Goal programming Penalty function E-learning system
http://www.sciencedirect.com/science/article/B6VCT-4TRK0NB-1/2/767d1b3d882411d2002807f70c87f78b
Chang, Ching-Ter
Lin, Teng-Chiao
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:800-8092009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:800-809
article
Analysis and evaluation of an Assemble-to-Order system with batch ordering policy and compound Poisson demand
We consider a multi-product and multi-component Assemble-to-Order (ATO) system where the external demand follows compound Poisson processes and component inventories are controlled by continuous-time batch ordering policies. The replenishment lead-times of components are stochastic, sequential and exogenous. Each element of the bill of material (BOM) matrix can be any non-negative integer. Components are committed to demand on a first-come-first-serve basis. We derive exact expressions for key performance metrics under either the assumption that each demand must be satisfied in full (non-split orders), or the assumption that each unit of demand can be satisfied separately (split orders). We also develop an efficient sampling method to estimate these metrics, e.g., the expected delivery lead-times and the order-based fill-rates. Based on the analysis and a numerical study of an example motivated by a real world application, we characterize the impact of the component interaction on system performance, demonstrate the efficiency of the numerical method and quantify the impact of order splitting.
Assemble-to-Order system Batch ordering policy Compound Poisson demand Order splitting
http://www.sciencedirect.com/science/article/B6VCT-4TT359Y-1/2/d0411b4c4a23cd2925be6090fe4eacf4
Zhao, Yao
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:899-9082009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:899-908
article
Stochastic programming based capacity planning for semiconductor wafer fab with uncertain demand and capacity
Capacity planning is a challenging problem in semiconductor manufacturing industry due to high uncertainties both in market and manufacturing systems, short product life cycle, and expensive capital invest. To tackle this problem, this paper proposes a scenario-based stochastic programming model which considers demand and capacity uncertainties via scenarios, where the overall equipment efficiency is employed to describe the uncertain capacity for the first time. Based on the decentralized structure of tool procurement, production, stockout, and inventory decision-making processes, recourse approximation strategies are presented with varying degree of information share. The computational experiments show that the resulting tool set is robust enough to cope with the changes in capacity with the expected profits being maximized for different scenarios, and the scheme can generate pretty good solutions in reasonable computational time.
OR in strategic planning Stochastic programming Optimization Scenarios Semiconductor manufacturing
http://www.sciencedirect.com/science/article/B6VCT-4TKPVC6-4/2/22049bcbbfa7f519e853156a4386157e
Geng, Na
Jiang, Zhibin
Chen, Feng
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:442-4472009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:442-447
article
Pure subgame-perfect equilibria in free transition games
We consider a class of stochastic games, where each state is identified with a player. At any moment during play, one of the players is called active. The active player can terminate the game, or he can announce any player, who then becomes the active player. There is a non-negative payoff for each player upon termination of the game, which depends only on the player who decided to terminate. We give a combinatorial proof of the existence of subgame-perfect equilibria in pure strategies for the games in our class.
Game theory Stochastic games Perfect information Subgame-perfection
http://www.sciencedirect.com/science/article/B6VCT-4V3HF9M-1/2/464d81e5d5067b7f0ea07aeb7685e217
Kuipers, J.
Flesch, J.
Schoenmakers, G.
Vrieze, K.
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:496-5052009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:496-505
article
An evolutionary approach to construction of outranking models for multicriteria classification: The case of the ELECTRE TRI method
Outranking methods constitute an important class of multicriteria classification models. Often, however, their implementation is cumbersome, due to the large number of parameters that the decision maker must specify. Past studies tried to address this issue using linear and nonlinear programming, to elicit the necessary preferential information from assignment examples. In this study, an evolutionary approach, based on the differential evolution algorithm, is proposed in the context of the ELECTRE TRI method. Computational results are given to test the effectiveness of the methodology and the quality of the obtained models.
Multi criteria analysis Classification Evolutionary computation Decision support systems
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-3/2/9ba8afa9d6a248c0caa35ca27e41a2a4
Doumpos, M.
Marinakis, Y.
Marinaki, M.
Zopounidis, C.
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:975-9782009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:975-978
article
Single machine scheduling with release dates and rejection
In this paper, we consider the single machine scheduling problem with release dates and rejection. A job is either rejected, in which case a rejection penalty has to be paid, or accepted and processed on the machine. The objective is to minimize the sum of the makespan of the accepted jobs and the total rejection penalty of the rejected jobs. We show that the problem is NP-hard in the ordinary sense. Then we provide two pseudo-polynomial-time algorithms. Consequently, two special cases can be solved in polynomial-time. Finally, a 2-approximation algorithm and a fully polynomial-time approximation scheme are given for the problem.
Scheduling Rejection penalty Fully polynomial-time approximation scheme
http://www.sciencedirect.com/science/article/B6VCT-4TRCYCP-3/2/f7d54666cae6da05da941a0491870e74
Zhang, Liqi
Lu, Lingfa
Yuan, Jinjiang
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:611-6172009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:611-617
article
A note on optimal ordering policies when the supplier provides a progressive interest scheme
Goyal et al. [Goyal, S.K., Teng, J.T., Chang, C.T., 2007. Optimal ordering policies when the supplier provides a progressive interest scheme. European Journal of Operational Research 179, 404-413] explore optimal ordering policies when the supplier provides a progressive interest scheme. The main purpose of this paper is fourfold: (1) This paper simplifies the total relevant cost per year Z(T) of Goyal et al. (2007) such that we can locate the optimal solutions of Z(T) by an easier way. (2) Goyal et al. (2007) use an algebraic approach to search for the optimal solution of Z(T). Their solution procedures ignore the explorations of the functional behavior of Z(T) such that their proofs fill shortcomings. This paper overcomes those shortcomings and presents a correct solution procedure for Goyal et al. (2007). (3) This paper demonstrates that the solution procedure in this paper can locate all optimal solutions of Z(T), however, that of Goyal et al. (2007) can only locate partially optimal solutions of Z(T). (4) Numerical examples reveal that Theorems 1(6) and 2(5) in Goyal et al. (2007) are not necessarily true, in general.
Finance Inventory EOQ Progressive interest charge
http://www.sciencedirect.com/science/article/B6VCT-4V42J7B-4/2/26909366131116f450bf6349ab0f6fce
Chung, Kun-Jen
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:859-8662009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:859-866
article
Two-stage queueing network models for quality control and testing
We study sojourn times in a two-node open queueing network with a processor sharing node and a delay node, with Poisson arrivals at the PS node. Motivated by quality control and blood testing applications, we consider a feedback mechanism in which customers may either leave the system after service at the PS node or move to the delay node; from the delay node, they always return to the PS node for new quality controls or blood tests. We propose various approximations for the distribution of the total sojourn time in the network; each of these approximations yields the exact mean sojourn time, and very accurate results for the variance. The best of the three approximations is used to tackle an optimization problem that is mainly inspired by a blood testing application.
Queueing Sojourn time Feedback Blood testing
http://www.sciencedirect.com/science/article/B6VCT-4TN0KW2-5/2/d8d6436d8715c92375c5995bd5d76582
Bar-Lev, Shaul K.
Boxma, Onno
Stadje, Wolfgang
Van der Duyn Schouten, Frank A.
Wiesmeyr, Christoph
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:750-7582009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:750-758
article
Scatter search for a real-life heterogeneous fleet vehicle routing problem with time windows and split deliveries in Brazil
In this paper, we consider a real-life heterogeneous fleet vehicle routing problem with time windows and split deliveries that occurs in a major Brazilian retail group. A single depot attends 519 stores of the group distributed in 11 Brazilian states. To find good solutions to this problem, we propose heuristics as initial solutions and a scatter search (SS) approach. Next, the produced solutions are compared with the routes actually covered by the company. Our results show that the total distribution cost can be reduced significantly when such methods are used. Experimental testing with benchmark instances is used to assess the merit of our proposed procedure.
Routing Scatter search Heterogeneous fleet Time windows Split deliveries
http://www.sciencedirect.com/science/article/B6VCT-4T5TPKF-2/2/e521a77cd8c0e2454c39e9a1d1c763e4
Belfiore, PatrIÂ´cia
Yoshida Yoshizaki, Hugo Tsugunobu
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:688-6962009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:688-696
article
Simulated annealing and tabu search for multi-mode project payment scheduling
This paper involves the multi-mode project payment scheduling problem where the activities can be performed with one of several discrete modes and the objective is to assign activities' modes and progress payments so as to maximize the net present value of the contractor under the constraint of project deadline. Using the event-based method the basic model of the problem is constructed and in terms of the different payment rules it is extended as the progress based, expense based, and time based models further. For the strong NP-hardness of the problem which is proven by simplifying it to the deadline subproblem of the discrete time-cost tradeoff problem, we develop two heuristic algorithms, namely simulated annealing and tabu search, to solve the problem. The two heuristic algorithms are compared with the multi-start iterative improvement method as well as random sampling on the basis of a computational experiment performed on a data set constructed by ProGen project generator. The results show that the proposed simulated annealing heuristic algorithm seems to be the most promising algorithm for solving the defined problem especially when the instances become larger. In addition, the effects of several key parameters on the net present value of the contractor are analyzed and some conclusions are given based on the results of the computational experiment.
Project scheduling Progress payments Net present value Simulated annealing Tabu search
http://www.sciencedirect.com/science/article/B6VCT-4TPF4FF-1/2/31b76438ef115830e3d75fd968403f40
He, Zhengwen
Wang, Nengmin
Jia, Tao
Xu, Yu
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:665-6732009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:665-673
article
Clique inference process for solving Max-CSP
Few works on problems CSP, Max-CSP and weighted CSP was carried out in the field of Combinatorial Optimization, whereas this field contains many algorithmic tools which can be used for the resolution of these problems. In this paper, we introduce the binary clique concept: clique which expresses incompatibilities between values of two CSP variables. We propose a linear formulation for any binary clique and we present several ways to exploit it in order to compute lower bounds or to solve Max-CSP. We also show that the binary clique concept can be exploited in the weighted CSP framework. The obtained theoretical and experimental results are very interesting and they open new prospects to exploit the Combinatorial Optimization algorithmic tools for the resolution of CSP, Max-CSP and weighted CSP.
Binary clique Max-CSP lower bounds Linear programming
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-4/2/97b94b4183eb068701aa6c2a056b9030
Idir Khemmoudj, Mohand Ou
Bennaceur, Hachemi
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:674-6832009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:674-683
article
Genetic algorithm based approach for the integrated airline crew-pairing and rostering problem
Airline crew scheduling problem is a complex and difficult problem faced by all airline companies. To tackle this problem, it was often decomposed into two subproblems solved successively. First, the airline crew-pairing problem, which consists on finding a set of trips - called pairings - i.e. sequences of flights, starting and ending at a crew base, that cover all the flights planned for a given period of time. Secondly, the airline crew rostering problem, which consists on assigning the pairings found by solving the first subproblem, to the named airline crew members. For both problems, several rules and regulations must be respected and costs minimized. It is sure that this decomposition provides a convenient tool to handle the numerous and complex restrictions, but it lacks, however, of a global treatment of the problem. For this purpose, in this study we took the challenge of proposing a new way to solve both subproblems simultaneously. The proposed approach is based on a hybrid genetic algorithm. In fact, three heuristics are developed here to tackle the restriction rules within the GA's process.
Airline application Combinatorial optimization Genetic algorithm Heuristics
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-7/2/cb87828a47bc0d1e2ce59e17b1b543c0
Souai, Nadia
Teghem, Jacques
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:187-1972009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:187-197
article
Optimal warranty policies for systems with imperfect repair
We investigate a system whose basic warranty coverage is minimal repair up to a specified warranty length. An additional service is offered whereby first failure is restored up to the consumers' chosen level of repair. The problem is studied under two system replacement strategies: periodic maintenance before and after warranty. It turns out that our model generalizes the model of Rinsaka and Sandoh [K. Rinsaka, H. Sandoh, A stochastic model with an additional warranty contract, Computers and Mathematics with Applications 51 (2006) 179-188] and the model of Yeh et al. [R.H. Yeh, M.Y. Chen, C.Y. Lin, Optimal periodic replacement policy for repairable products under free-repair warranty, European Journal of Operational Research 176 (2007) 1678-1686]. We derive the optimal maintenance period and optimal level of repair based on the structures of the cost function and failure rate function. We show that under certain assumptions, the optimal repair level for additional service is an increasing function of the replacement time. We provide numerical studies to verify some of our results.
Reliability Long-run expected cost Minimal repair Renewal process Non-homogeneous Poisson process Warranty
http://www.sciencedirect.com/science/article/B6VCT-4TY9MPF-1/2/e8a36f815dcff3ac07735a9d58300fd2
Yeo, Wee Meng
Yuan, Xue-Ming
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:387-3912009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:387-391
article
The tricriterion shortest path problem with at least two bottleneck objective functions
The focus of this paper is on the tricriterion shortest path problem where two objective functions are of the bottleneck type, for example MinMax or MaxMin. The third objective function may be of the same kind or we may consider, for example, MinSum or MaxProd. Let p(n) be the complexity of a classical single objective algorithm responsible for this third function, where n is the number of nodes and m be the number of arcs of the graph. An O(m2p(n)) algorithm is presented that can generate the minimal complete set of Pareto-optimal solutions. Finding the maximal complete set is also possible. Optimality proofs are given and extensions for several special cases are presented. Computational experience for a set of randomly generated problems is reported.
Multicriteria shortest path problem Pareto-optimal solution
http://www.sciencedirect.com/science/article/B6VCT-4TN0KW2-1/2/1d2189b7d90350eb944c45df0aaea195
de Lima Pinto, Leizer
Bornstein, Cláudio Thomás
Maculan, Nelson
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:557-5702009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:557-570
article
Third-order extensions of Lo's semiparametric bound for European call options
Computing semiparametric bounds for option prices is a widely studied pricing technique. In contrast to parametric pricing techniques, such as Monte-Carlo simulations, semiparametric pricing techniques do not require strong assumptions about the underlying asset price distribution. We extend classical results in this area. Specifically, we derive closed-form semiparametric bounds for the payoff of a European call option, given up to third-order moment (i.e., mean, variance, and skewness) information on the underlying asset price. We analyze how these bounds tighten the corresponding bounds, when only second-order moment (i.e., mean and variance) information is provided. We describe applications of these results in the context of option pricing; as well as in other areas such as inventory management, and actuarial science.
Applied probability Option pricing Inventory management Stop-loss premium Third moment
http://www.sciencedirect.com/science/article/B6VCT-4TJTX6N-1/2/5f95fe85b74bad42c4f098e0a49373fa
Zuluaga, Luis F.
Peña, Javier
Du, Donglei
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:857-8662009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:857-866
article
Structuring decision problems: A case study and reflections for practitioners
This article reviews several approaches to problem structuring and, in particular, the three-step structuring process for decision analysis proposed by von Winterfeldt and Edwards: (1) identifying the problem; (2) selecting an appropriate analytical approach; (3) developing the a detailed analytic structure. This three-step process is re-examined in the context of a decision analysis of alternative policies to reduce electromagnetic field exposure from electric power lines. This decision analysis was conducted for a public health organization funded by the California Public Utilities Commission and it was scrutinized throughout by interested stakeholders. As a result a significant effort went into structuring this problem appropriately, with some successes and some missteps. The article extracts lessons from this experience, updating existing guidance on structuring problems for decision analysis, and concluding with some general insights for problem structuring.
Problem structuring Decision analysis Decision analysis application Evaluation Stakeholders Detailed structures Mixing models Behavioural decision making lessons
http://www.sciencedirect.com/science/article/B6VCT-4VYXMKW-4/2/bf299f8d4a390e97939efd21fe933e00
von Winterfeldt, Detlof
Fasolo, Barbara
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:619-6192009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:619-619
article
Cooperative combinatorial optimization
http://www.sciencedirect.com/science/article/B6VCT-4S8TB73-1/2/feee245244d4b4dd68ad40b25cc6b05d
Talbi, El-Ghazali
Dhaenens, Clarisse
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:385-3992009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:385-399
article
An integrated tabu search algorithm for the lot streaming problem in job shops
In this paper, we focus on solving the lot streaming problem in a job shop environment, where consistent sublots are considered. The presented three-phase algorithm incorporates the predetermination of sublot sizes, the determination of schedules based on tabu search and the variation of sublot sizes. With regard to tabu search implementation, a constructive multi-level neighbourhood is developed, which effectively connects three isolated neighbourhood functions. Moreover, enhancements of the basic version of tabu search are conducted. Combined with the procedure for varying sublot sizes, the algorithm further exploits the improvement potential. All tested instances show a rapid convergence to their lower bounds. The well-known difficult benchmark problems also achieve substantial makespan reduction. In addition, the performance of specific components is intensively examined in our study.
Lot streaming techniques The job shop problem Tabu search
http://www.sciencedirect.com/science/article/B6VCT-4V4VY5V-1/2/4f7740f9d0bbd6d4aaf5e9245864033c
Buscher, Udo
Shen, Liji
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:595-6002009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:595-600
article
Minimizing the number of machines for scheduling jobs with equal processing times
In this paper, we consider a parallel machine environment when all jobs have the same processing time and arbitrary release dates and deadlines of the jobs are given. We suppose that the available number of machines, which can be used simultaneously, may vary over time. The aim is to construct a feasible schedule in such a way that the maximal number of simultaneously used machines is minimal. We give a polynomial algorithm for this problem.
Parallel machine scheduling Linear programming
http://www.sciencedirect.com/science/article/B6VCT-4TRCYCP-2/2/9f53b6d9a3568ec7c087c138fe193217
Kravchenko, Svetlana A.
Werner, Frank
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:323-3332009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:323-333
article
Enhanced-interval linear programming
An enhanced-interval linear programming (EILP) model and its solution algorithm have been developed that incorporate enhanced-interval uncertainty (e.g., AÂ±, BÂ± and CÂ±) in a linear optimization framework. As a new extension of linear programming, the EILP model has the following advantages. Its solution space is absolutely feasible compared to that of interval linear programming (ILP), which helps to achieve insight into the expected-value-oriented trade-off between system benefits and risks of constraint violations. The degree of uncertainty of its enhanced-interval objective function (EIOF) would be lower than that of ILP model when the solution space is absolutely feasible, and the EIOF's expected value could be used as a criterion for generating the appropriate alternatives, which help decision-makers obtain non-extreme decisions. Moreover, because it can be decomposed into two submodels, EILP's computational requirement is lower than that of stochastic and fuzzy LP models. The results of a numeric example further indicated the feasibility and effectiveness of EILP model. In addition, EI nonlinear programming models, hybrid stochastic or fuzzy EILP models as well as risk-based trade-off analysis for EI uncertainty within decision process can be further developed to improve its applicability.
Linear programming Optimization Uncertainty Feasibility Solution algorithm Risk-based decision making
http://www.sciencedirect.com/science/article/B6VCT-4V7622K-3/2/8d649d118822a485e6d6adc766b0b4d5
Zhou, Feng
Huang, Gordon H.
Chen, Guo-Xian
Guo, Huai-Cheng
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:726-7332009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:726-733
article
Modeling cooperation on a class of distribution problems
In this paper we study models of cooperation between the nodes of a network that represents a distribution problem. The distribution problem we propose arises when, over a graph, a group of nodes offers certain commodity, some other nodes require it and a third group of nodes neither need this material nor offer it but they are strategically relevant to the distribution plan. The delivery of one unit of material to a demand node generates a fixed profit, and the shipping of the material through the arcs has an associated cost. We show that in such a framework cooperation is beneficial for the different parties. We prove that the cooperative situation arising from this distribution problem is totally balanced by finding a set of stable allocations (in the core of an associated cooperative game). In order to overcome certain fairness problems of these solutions, we introduce two new solution concepts and study their properties.
OR in strategic planning Game theory Supply chain management
http://www.sciencedirect.com/science/article/B6VCT-4TN82H3-2/2/e80c77dea23c81ff6fdd573ac708723f
Perea, F.
Puerto, J.
Fernández, F.R.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:520-5292009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:520-529
article
Designing charts for known autocorrelations and unknown marginal distribution
In the design of the control chart, both the sample size m of and the control-limit factor k (the number of standard deviations from the center line) must be determined. We address this problem under the assumption that the quality characteristic follows an autocorrelated process with known covariance structure but unknown marginal distribution shape. We propose two methods for determining m and k, chosen to minimize the out-of-control ARL (average run length) while maintaining the in-control ARL at a specified value. Method 1 calculates the ARL values as if the sample means were independent normal random variables; Method 2 calculates the ARL values as if the sample means were an AR(1) process. Method 2 outperforms Method 1 when the correlation and mean shift are both high. We also modify Methods 1 and 2 with a minimum sample size of 30; the modification moves the in-control ARL closer to the specified value. Our numerical results show that the modified Method 2 performs better than two previous design procedures, especially when the correlation is high.
Average run length Covariance stationary Optimization SPC
http://www.sciencedirect.com/science/article/B6VCT-4TF7C95-1/2/4719faa96c2997ebd5acd97452cd0086
Chen, Huifen
Cheng, Yuyen
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:400-4082009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:400-408
article
Optimal policy for a dynamic, non-stationary, stochastic inventory problem with capacity commitment
This paper studies a single-product, dynamic, non-stationary, stochastic inventory problem with capacity commitment, in which a buyer purchases a fixed capacity from a supplier at the beginning of a planning horizon and the buyer's total cumulative order quantity over the planning horizon is constrained with the capacity. The objective of the buyer is to choose the capacity at the beginning of the planning horizon and the order quantity in each period to minimize the expected total cost over the planning horizon. We characterize the structure of the minimum sum of the expected ordering, storage and shortage costs in a period and thereafter and the optimal ordering policy for a given capacity. Based on the structure, we identify conditions under which a myopic ordering policy is optimal and derive an equation for the optimal capacity commitment. We then use the optimal capacity and the myopic ordering policy to evaluate the effect of the various parameters on the minimum expected total cost over the planning horizon.
Additive function Capacity Inventory Myopic policy Stochastic dynamic programming
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-6/2/f9b276e931653c8a8794ff4eecb8bdd1
Xu, Ningxiong
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:176-1862009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:176-186
article
Importance sampling algorithms for first passage time probabilities in the infinite server queue
This paper applies importance sampling simulation for estimating rare event probabilities of the first passage time in the infinite server queue with renewal arrivals and general service time distributions. We consider importance sampling algorithms which are based on large deviations results of the infinite server queue, and we consider an algorithm based on the cross-entropy method, where we allow light-tailed and heavy-tailed distributions for the interarrival times and the service times. Efficiency of the algorithms is discussed by simulation experiments.
Simulation Queueing Rare events Importance sampling
http://www.sciencedirect.com/science/article/B6VCT-4TW1348-1/2/be7ec5df1c88d5bab5457b448595e60d
Ridder, Ad
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:232-2352009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:232-235
article
Mathematical programming accelerates implementation of agro-industrial sugarcane complex
With the current demand for Brazilian sugarcane, the importance to investors of a faster implementation of agro-industrial complexes has been increasing. Estimates suggest that a 4-year implementation may enhance financial value creation by 10% when compared to the usual 6-year implementation. Given a desired production and a target implementation horizon, the quadratic programming model presented in this paper offers a feasible plantation schedule with minimum deviation from the plan. The model was used as an important tool in two business plans.
OR in agriculture OR in developing countries Quadratic programming Farm planning Sugarcane scheduling Valuation
http://www.sciencedirect.com/science/article/B6VCT-4V0TD2N-3/2/e868a69f5edfd2cb4739975f5ce6d10a
Colin, Emerson C.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:378-3862009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:378-386
article
Complete local search with limited memory algorithm for no-wait job shops to minimize makespan
In this paper, no-wait job shop problems with makespan minimization are considered. It is well known that these problems are strongly NP-hard. The problem is decomposed into the sequencing and the timetabling components. Shift timetabling is developed for the timetabling component. An effective method, CLLM (complete local search with limited memory), is presented by integrating with shift timetabling for the sequencing component. Experimental results show that CLLM outperforms all the existing effective algorithms for the considered problem with a little more computation time.
No-wait Job shop Timetabling Sequencing
http://www.sciencedirect.com/science/article/B6VCT-4THC1CX-4/2/02323adf1e14a3b550a19377f3038c89
Zhu, Jie
Li, Xiaoping
Wang, Qian
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:878-8902009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:878-890
article
Pattern search ranking and selection algorithms for mixed variable simulation-based optimization
The class of generalized pattern search (GPS) algorithms for mixed variable optimization is extended to problems with stochastic objective functions. Because random noise in the objective function makes it more difficult to compare trial points and ascertain which points are truly better than others, replications are needed to generate sufficient statistical power to draw conclusions. Rather than comparing pairs of points, the approach taken here augments pattern search with a ranking and selection (R&S) procedure, which allows for comparing many function values simultaneously. Asymptotic convergence for the algorithm is established, numerical issues are discussed, and performance of the algorithm is studied on a set of test problems.
Pattern search algorithms Mixed variable programming Nonlinear programming Simulation Ranking and selection
http://www.sciencedirect.com/science/article/B6VCT-4TVHSMF-1/2/e296ab9b18906a63877874128d41cbfd
Sriver, Todd A.
Chrissis, James W.
Abramson, Mark A.
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:459-4672009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:459-467
article
A framework for participatory decision support using Pareto frontier visualization, goal identification and arbitration
There is a growing interest in promoting participation of lay stakeholders in public decision-making processes, possibly with the aid of Internet-based systems. This implies supporting non-sophisticated users and, consequently, developing user-friendly, yet rigorous, participatory decision support methods. We outline a framework to develop such methods based on interactive Pareto frontier visualization combined with expression of preferences in terms of feasible goals and using feasible goal-based arbitration.
Decision analysis Participatory decision support Pareto frontier visualization Feasible goals Arbitration methods e-Democracy
http://www.sciencedirect.com/science/article/B6VCT-4TXF7XP-1/2/df62ec024c06259c1098f844bc9b8289
Efremov, Roman
Insua, David Rios
Lotov, Alexander
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:359-3742009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:359-374
article
Balancing assembly lines with variable parallel workplaces: Problem definition and effective solution procedure
Assembly line balancing problems (ALBP) arise whenever an assembly line is configured, redesigned or adjusted. An ALBP consists of distributing the total workload for manufacturing any unit of the products to be assembled among the work stations along the line subject to a strict or average cycle time. Traditionally, stations are considered to be manned by one operator, respectively, or duplicated in form of identical parallel stations, each also manned by a single operator. In practice, this assumption is usually too restrictive. This is particularly true for large products like cars, trucks, busses and machines, which can be handled by several operators performing different tasks at the same time. Only restricted research has been done on such parallel workplaces within the same station though they have significant relevance in real-world assembly line settings. In this paper, we consider an extension of the basic ALBP to the case of flexible parallel workplaces (VWALBP) as they typically occur in the automobile and other industries assembling large products. The problem is defined and modelled as an integer linear program. As a solution approach a branch-and-bound procedure is proposed which also can be applied as a heuristic. Finally, computational experiments documenting the solution capabilities of the procedure are reported.
Assembly line balancing Mass-production Combinatorial optimization Sequencing
http://www.sciencedirect.com/science/article/B6VCT-4V75YRV-1/2/c16659ca2c3ce2f8ec859f3de4b5111a
Becker, Christian
Scholl, Armin
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:392-4042009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:392-404
article
Adaptive automated construction of hybrid heuristics for exam timetabling and graph colouring problems
In this paper, we present a random iterative graph based hyper-heuristic to produce a collection of heuristic sequences to construct solutions of different quality. These heuristic sequences can be seen as dynamic hybridisations of different graph colouring heuristics that construct solutions step by step. Based on these sequences, we statistically analyse the way in which graph colouring heuristics are automatically hybridised. This, to our knowledge, represents a new direction in hyper-heuristic research. It is observed that spending the search effort on hybridising Largest Weighted Degree with Saturation Degree at the early stage of solution construction tends to generate high quality solutions. Based on these observations, an iterative hybrid approach is developed to adaptively hybridise these two graph colouring heuristics at different stages of solution construction. The overall aim here is to automate the heuristic design process, which draws upon an emerging research theme on developing computer methods to design and adapt heuristics automatically. Experimental results on benchmark exam timetabling and graph colouring problems demonstrate the effectiveness and generality of this adaptive hybrid approach compared with previous methods on automatically generating and adapting heuristics. Indeed, we also show that the approach is competitive with the state of the art human produced methods.
Adaptive Exam timetabling Graph colouring Graph colouring heuristics Hybridisation Hyper-heuristic
http://www.sciencedirect.com/science/article/B6VCT-4TPF4FF-2/2/12b081bc990e66d8d6ae436ebbd0db74
Qu, Rong
Burke, Edmund K.
McCollum, Barry
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:339-3482009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:339-348
article
An iterative variable-based fixation heuristic for the 0-1 multidimensional knapsack problem
An iterative scheme which is based on a dynamic fixation of the variables is developed to solve the 0-1 multidimensional knapsack problem. Such a scheme has the advantage of generating memory information, which is used on the one hand to choose the variables to fix either permanently or temporarily and on the other hand to construct feasible solutions of the problem. Adaptations of this mechanism are proposed to explore different parts of the search space and to enhance the behaviour of the algorithm. Encouraging results are presented when tested on the correlated instances of the 0-1 multidimensional knapsack problem.
Heuristics Exact methods Fixation techniques Knapsack
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-2/2/7621fe77d1244e1a302da97d2df702de
Wilbaut, Christophe
Salhi, Saïd
Hanafi, Saïd
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:262-2752009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:262-275
article
Exploring the VCG mechanism in combinatorial auctions: The threshold revenue and the threshold-price rule
We explore interesting potential extensions of the Vickrey-Clarke-Groves (VCG) rule under the assumption of players with independent and private valuations and no budget constraints. First, we apply the VCG rule to a coalition of bidders in order to compute the second price of the coalition. Then, we introduce and formulate the problem of determining that partition of players into coalitions which maximize the auctioneer's revenue in the case whereby such coalitions take part to a VCG auction each one as a single agent; in particular, we provide an integer linear formulation of this problem. We also generalize this issue by allowing players to simultaneously belong to distinct coalitions in the case that players' valuation functions are separable. Finally, we propose some applications of these theoretical results. For instance, we exploit them to provide a class of new payment rules and to decide which bids should be defined as the highest losing ones in combinatorial auctions.
Auctions/bidding VCG rule Coalitions Revenues Payment rules
http://www.sciencedirect.com/science/article/B6VCT-4TVJ3KV-1/2/bbc28129c190bf184b77904f0665533b
Avenali, Alessandro
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:448-4582009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:448-458
article
Statistical testing of optimality conditions in multiresponse simulation-based optimization
This article studies simulation-based optimization with multiple outputs. It assumes that the simulation model has one random objective function and must satisfy given constraints on the other random outputs. It presents a statistical procedure for testing whether a specific input combination (proposed by some optimization heuristic) satisfies the Karush-Kuhn-Tucker (KKT) first-order optimality conditions. The article focuses on "expensive" simulations, which have small sample sizes. The article applies the classic t test to check whether the specific input combination is feasible, and whether any constraints are binding; next, it applies bootstrapping (resampling) to test the estimated gradients in the KKT conditions. The new methodology is applied to three examples, which gives encouraging empirical results.
Stopping rule Metaheuristics Response surface methodology Design of experiments Kriging
http://www.sciencedirect.com/science/article/B6VCT-4V7622K-1/2/b5e7571d69fa7026b71aad23cfe798d4
Bettonvil, Bert
del Castillo, Enrique
Kleijnen, Jack P.C.
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:506-5112009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:506-511
article
A variable selection method based on Tabu search for logistic regression models
A Tabu search method is proposed and analysed for selecting variables that are subsequently used in Logistic Regression Models. The aim is to find from among a set of m variables a smaller subset which enables the efficient classification of cases. Reducing dimensionality has some very well-known advantages that are summarized in literature. The specific problem consists in finding, for a small integer value of p, a subset of size p of the original set of variables that yields the greatest percentage of hits in Logistic Regression. The proposed Tabu search method performs a deep search in the solution space that alternates between a basic phase (that uses simple moves) and a diversification phase (to explore regions not previously visited). Testing shows that it obtains significantly better results than the Stepwise, Backward or Forward methods used by classic statistical packages. Some results of applying these methods are presented.
Variable selection Logistic regression Metaheuristics Tabu search
http://www.sciencedirect.com/science/article/B6VCT-4TRCYCP-1/2/7c7aa8be590d27c17b6fe91c4d4e419e
Pacheco, Joaquín
Casado, Silvia
Núñez, Laura
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:602-6092009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:602-609
article
Multicriteria sorting using a valued indifference relation under a preference disaggregation paradigm
Most multicriteria decision methods need the definition of a significant amount of preferential information from a decision agent. The preference disaggregation analysis paradigm infers the model's parameter values from holistic judgments provided by a decision agent. Here, a new method for inferring the parameters of a fuzzy outranking model for multicriteria sorting is proposed. This approach allows us to use most of the preferential information contained in a reference set. The central idea is to characterize the quality of the model by measuring discrepancies and concordances amongst (i) the preference relations derived from the outranking model, and (ii) the preferential information contained in the reference set. The model's parameters are inferred from a multiobjective optimization problem, according to some additional preferential information from a decision agent. Once the model has been fitted, sorting decisions about new objects are performed by using a fuzzy indifference relation. This proposal performs very well in some examples.
Multicriteria classification Fuzzy outranking relations Parameter elicitation Evolutionary multiobjective optimization
http://www.sciencedirect.com/science/article/B6VCT-4TJTX6N-2/2/da1fac9535541ad1b84169c1b914d31b
Fernandez, Eduardo
Navarro, Jorge
Bernal, Sergio
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:936-9422009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:936-942
article
Simulation optimization for an emergency department healthcare unit in Kuwait
This paper integrates simulation with optimization to design a decision support tool for the operation of an emergency department unit at a governmental hospital in Kuwait. The hospital provides a set of services for different categories of patients. We present a methodology that uses system simulation combined with optimization to determine the optimal number of doctors, lab technicians and nurses required to maximize patient throughput and to reduce patient time in the system subject to budget restrictions. The major objective of this decision supporting tool is to evaluate the impact of various staffing levels on service efficiency. Experimental results show that by using current hospital resources, the optimization simulation model generates optimal staffing allocation that would allow 28% increase in patient throughput and an average of 40% reduction in patients' waiting time.
Health services Stochastic optimization Simulation Decision support system
http://www.sciencedirect.com/science/article/B6VCT-4TVTJKM-2/2/70fbaa51d363ee5f2b8208691cd0050a
Ahmed, Mohamed A.
Alkhamis, Talal M.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:576-6012009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:576-601
article
An improved multiobjective differential evolution based on Pareto-adaptive [epsilon]-dominance and orthogonal design
Evolutionary multiobjective optimization has become a very popular topic in the last few years. Since the 1980s, various evolutionary approaches that are capable of searching for multiple solutions simultaneously in a single run have been developed to solve multiobjective optimization problems (MOPs). However, to find a uniformly distributed, near-complete, and near-optimal Pareto front in a small number of fitness function evaluations (NFFEs) is a challenging task for any multiobjective optimization evolutionary algorithm (MOEA). In this paper, we present an improved differential evolution algorithm to MOPs that combines several features of previous evolutionary algorithms in a unique manner. It is characterized by (a) employing the orthogonal design method with quantization technique to generate the initial population, (b) adopting an archive to store the nondominated solutions and employing the new Pareto-adaptive [epsilon]-dominance method to update the archive at each generation, (c) storing the extreme points and inserting them into the final archive in order to remedy one of the limitations of [epsilon]-dominance: the loss of the extreme points in the final archive, and (d) using a hybrid selection mechanism in which a random selection and an elitist selection are alternated in order to allow using the archive solution to guide the search towards the Pareto-optimal front. Experiments have been conducted on a number of unconstrained real-valued artificial functions of two and three objectives. The results prove the efficiency of our approach with respect to the quality of the approximation of the Pareto-optimal front and the considerable reduction of NFFEs in these test problems. By examining the selected performance metrics, our approach is found to be statistically competitive with five state-of-the-art MOEAs in terms of keeping the diversity of the individuals along the tradeoff surface, finding a well-approximated Pareto-optimal front and reducing the computational effort.
Multiobjective optimization Differential evolution algorithm Pareto-adaptive [epsilon]-dominance Orthogonal design method
http://www.sciencedirect.com/science/article/B6VCT-4TK479X-1/2/fcaf41c5ad03d70875d54f5eda6df315
Gong, Wenyin
Cai, Zhihua
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:734-7402009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:734-740
article
An empirical study on the benefit of split loads with the pickup and delivery problem
Splitting loads such that the delivery of certain loads is completed in multiple trips rather than one trip has been shown to have benefit for both the classic Vehicle Routing Problem (VRP) and the Pickup and Delivery Problem (PDP). However, the magnitude of the benefit may be affected by various problem characteristics. In this paper, we characterize those real world environments in which split loads are most likely to be beneficial. Based on practitioner interest, we determine how the benefit is affected by the mean load size and variance, number of origins relative to the number of destinations, the percentage of origin-destination pairs with a load requiring service, and the clustering of origin and destination locations. We find that the magnitude of benefit is greatest for load sizes just over one half vehicle capacity as these loads can not be combined without splitting, while they are the easiest to combine on a vehicle with splitting; increases as the number of loads sharing an origin or destination increases because there are more potential load combinations to split at each stop; and increases as the average distance from an origin to a destination increases because splitting loads reduces the trips from origins to destinations.
Transportation Vehicle routing Split pickup and delivery
http://www.sciencedirect.com/science/article/B6VCT-4TN0KW2-6/2/2c391aa9aebf93885310859b892efc55
Nowak, Maciek
Ergun, Ozlem
White III, Chelsea C.
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:715-7252009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:715-725
article
Simultaneously scheduling multiple turns for steel color-coating production
This paper investigates a large-scale scheduling problem in the iron and steel industry, called color-coating production scheduling (CCPS). The problem is to generate multiple production turns for the galvanized coils that dynamically arrive from upstream lines within a given scheduling horizon, and at the same time determine the sequence of these turns so that the productivity and product quality are maximized while the production cost and the number of generated turns are minimized. We formulate this problem as a mixed integer nonlinear program and propose a tabu search heuristic to obtain satisfactory solutions. Results on real production instances show that the presented model and heuristic are more effective and efficient with comparison to manual scheduling. A practical scheduling system for CCPS combining the model and heuristic has been developed and successfully implemented in a major iron and steel enterprise in China.
Color-coating production scheduling Mixed integer nonlinear programming Tabu search
http://www.sciencedirect.com/science/article/B6VCT-4TK92DH-1/2/5df3d408b306b5a7159d5e1c5897108a
Tang, Lixin
Wang, Xianpeng
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:811-8222009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:811-822
article
University objectives and socioeconomic results: A multicriteria measuring of alignment
Universities develop technology transfer mechanisms as the tools required to undertake missions committed to the socioeconomic environment. In this work a new proposal to measure the extent to which the goals or strategic objectives of a university are aligned with the results obtained through its technology transfer mechanisms with the local community is presented. This will enable to perform a diagnosis, by comparing the situation sought by the University Management team (expected case) with the actual one that derives from the application of the plans that implement the technology transfer mechanisms (real case). To achieve this, two different Multicriteria Decision Analysis techniques e.g. Analytic Network Process (ANP) and Analytic Hierarchy Process (AHP) will be used. Both the methodology and the MCDA techniques proposed need to be explained and clarified to the different experts who collaborate in the study, hence the facilitating process, key to the whole procedure, will be analysed in detail. The model proposed in this study is applied to analyse the case of the National University of Colombia - Bogotá Campus. Findings show that the following questions can be answered: (i) How much importance is granted by the University Management to the objectives of the University? (ii) To what extent are the objectives of the university fulfilled by the technology transfer mechanisms to the socioeconomic environment? (iii) Are the objectives of the university aligned with the results achieved through the technology transfer mechanisms?
Multiple criteria analysis Analytic network process (ANP) Analytic hierarchy process (AHP) Relation between university and socioeconomic environment
http://www.sciencedirect.com/science/article/B6VCT-4W04KHG-3/2/25d8bbcb0dc195a0ad1632f226f367f4
Cortés-Aldana, Félix Antonio
García-Melón, Mónica
Fernández-de-Lucio, Ignacio
Aragonés-Beltrán, Pablo
Poveda-Bautista, Rocío
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:684-6932009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:684-693
article
Portfolio optimization with an envelope-based multi-objective evolutionary algorithm
The problem of portfolio selection is a standard problem in financial engineering and has received a lot of attention in recent decades. Classical mean-variance portfolio selection aims at simultaneously maximizing the expected return of the portfolio and minimizing portfolio variance. In the case of linear constraints, the problem can be solved efficiently by parametric quadratic programming (i.e., variants of Markowitz' critical line algorithm). However, there are many real-world constraints that lead to a non-convex search space, e.g., cardinality constraints which limit the number of different assets in a portfolio, or minimum buy-in thresholds. As a consequence, the efficient approaches for the convex problem can no longer be applied, and new solutions are needed. In this paper, we propose to integrate an active set algorithm optimized for portfolio selection into a multi-objective evolutionary algorithm (MOEA). The idea is to let the MOEA come up with some convex subsets of the set of all feasible portfolios, solve a critical line algorithm for each subset, and then merge the partial solutions to form the solution of the original non-convex problem. We show that the resulting envelope-based MOEA significantly outperforms existing MOEAs.
Portfolio optimization Evolutionary algorithm Multi-objective
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-8/2/2638f5fb2583431bda3a22f2c2c41580
Branke, J.
Scheckenbach, B.
Stein, M.
Deb, K.
Schmeck, H.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:883-8912009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:883-891
article
Tradeoff-based decomposition and decision-making in multiobjective programming
To facilitate the evaluation of tradeoffs and the articulation of preferences in multiple criteria decision-making, a multiobjective decomposition scheme is proposed that restructures the original problem as a collection of smaller-sized subproblems with only subsets of the original criteria. A priori preferences on objective tradeoffs are integrated into this process by modifying the ordinary Pareto order by more general domination cones, and decision makers are supported by an interactive decision-making procedure to coordinate any remaining tradeoffs using concepts of approximate efficiency. A theoretical foundation for this method is provided, and an illustrative application to multiobjective portfolio optimization is described in detail.
Multiobjective programming Multicriteria decision-making Preferences Tradeoffs Decomposition Domination cones Approximate efficiency Portfolio optimization
http://www.sciencedirect.com/science/article/B6VCT-4VYP94C-5/2/c21865b35f9806b06f42bb237a83074b
Engau, Alexander
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:902-9072009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:902-907
article
Electric load forecasting methods: Tools for decision making
For decision makers in the electricity sector, the decision process is complex with several different levels that have to be taken into consideration. These comprise for instance the planning of facilities and an optimal day-to-day operation of the power plant. These decisions address widely different time-horizons and aspects of the system. For accomplishing these tasks load forecasts are very important. Therefore, finding an appropriate approach and model is at core of the decision process. Due to the deregulation of energy markets, load forecasting has gained even more importance. In this article, we give an overview over the various models and methods used to predict future load demands.
Electric load forecasting Energy markets Decision making Survey
http://www.sciencedirect.com/science/article/B6VCT-4VYXMKW-1/2/4c07e825afa512dbb8485bd6c8c2c30f
Hahn, Heiko
Meyer-Nieberg, Silja
Pickl, Stefan
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:25-352009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:25-35
article
Multi-objective integer programming: A general approach for generating all non-dominated solutions
In this paper we develop a general approach to generate all non-dominated solutions of the multi-objective integer programming (MOIP) Problem. Our approach, which is based on the identification of objective efficiency ranges, is an improvement over classical [epsilon]-constraint method. Objective efficiency ranges are identified by solving simpler MOIP problems with fewer objectives. We first provide the classical [epsilon]-constraint method on the bi-objective integer programming problem for the sake of completeness and comment on its efficiency. Then present our method on tri-objective integer programming problem and then extend it to the general MOIP problem with k objectives. A numerical example considering tri-objective assignment problem is also provided.
Multiple objective programming Integer programming
http://www.sciencedirect.com/science/article/B6VCT-4TVJ3KV-3/2/552854ec23e4298fa77a8e138adbb50c
Özlen, Melih
Azizoglu, Meral
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:744-7492009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:744-749
article
Efficient computation of time-based customer service levels in a multi-item, multi-echelon supply chain: A practical approach for inventory optimization
Time-based item fill rates, or "channel" fill rates, are the building blocks needed to evaluate steady-state compliance with time-based customer service agreements. Exact computation of channel fill rates is both difficult and time-consuming, yet their accurate assessment is essential for system-wide inventory optimization. We describe and validate a practical method for computing channel fill rates in a multi-item, multi-echelon service parts distribution system. A simulation study is presented which shows that, in a three-echelon setting, our estimation errors are very small over a wide range of base stock level vectors. A more accurate, though less efficient, approximation method is also evaluated for comparison.
Inventory and service optimization Distribution resource planning Multi-echelon inventory Service parts management Time-based fill rates Modeling methodologies
http://www.sciencedirect.com/science/article/B6VCT-4T5TPKF-3/2/78f9fdc8d14924362def15e546f02d24
Caggiano, Kathryn E.
Jackson, Peter L.
Muckstadt, John A.
Rappold, James A.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:694-6942009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:694-694
article
Feature cluster: Planning and scheduling in industrial and logistic systems
http://www.sciencedirect.com/science/article/B6VCT-4SSND55-1/2/52aa032d0036dd0ee33c9d14317e6ebd
Dauzère-Pérès, Stéphane
Sauer, Nathalie
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:542-5522009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:542-552
article
A cross entropy approach to design of reliable networks
One of the most important parameters determining the performance of communication networks is network reliability. The network reliability strongly depends on not only topological layout of the communication networks but also reliability and availability of the communication facilities. The selection of optimal network topology is an NP-hard problem so that computation time of enumeration-based methods grows exponentially with network size. This paper presents a new solution approach based on cross-entropy method, called NCE, to design of communication networks. The design problem is to find a network topology with minimum cost such that all-terminal reliability is not less than a given level of reliability. To investigate the effectiveness of the proposed NCE, comparisons with other heuristic approaches given in the literature for the design problem are carried out in a three-stage experimental study. Computational results show that NCE is an effective heuristic approach to design of reliable networks.
Communication networks Network design Network reliability Cross-entropy method Meta-heuristics Monte Carlo technique
http://www.sciencedirect.com/science/article/B6VCT-4V1TXRD-2/2/32cff56489b4821e74679fbaa259e495
Altiparmak, Fulya
Dengiz, Berna
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:520-5302009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:520-530
article
A reference model for customer-centric data mining with support vector machines
Supervised classification is an important part of corporate data mining to support decision making in customer-centric planning tasks. The paper proposes a hierarchical reference model for support vector machine based classification within this discipline. The approach balances the conflicting goals of transparent yet accurate models and compares favourably to alternative classifiers in a large-scale empirical evaluation in real-world customer relationship management applications. Recent advances in support vector machine oriented research are incorporated to approach feature, instance and model selection in a unified framework.
Marketing Data mining Customer relationship management Support vector machines
http://www.sciencedirect.com/science/article/B6VCT-4V75YRV-2/2/55087e9e8fc8046688601d48ff6a6817
Lessmann, Stefan
Voß, Stefan
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:530-5442009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:530-544
article
Weighted multiple majority games with unions: Generating functions and applications to the European Union
An a priori system of unions or coalition structure is a partition of a finite set of players into disjoint coalitions which have made a prior commitment to cooperate in playing a game. This paper provides "ready-to-apply" procedures based on generating functions that are easily implementable to compute coalitional power indices in weighted multiple majority games. As an application of the proposed procedures, we calculate and compare coalitional power indices under the decision rules prescribed by the Treaty of Nice and the new rules proposed by the Council of the European Union.
Multiple majority games Generating functions Coalitional power indices
http://www.sciencedirect.com/science/article/B6VCT-4THC1CX-1/2/475ce2e53fd3d30e3329f635cdbf49a6
Alonso-Meijide, J.M.
Bilbao, J.M.
Casas-Méndez, B.
Fernández, J.R.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:21-242009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:21-24
article
Robust model selection criteria for robust Liu estimator
In linear regression analysis, outliers often have large influence in the model/variable selection process. The aim of this study is to select the subsets of independent variables which explain dependent variables in the presence of multicollinearity, outliers and possible departures from the normality assumption of the error distribution in robust regression analysis. In this study to overcome this combined problem of multicollinearity and outliers, we suggest to use robust selection criterion with Liu and Liu-type M(LM) estimators.
Liu-estimator Robust-Liu estimator M-estimator Robust Cp Robust Tp Robust model selection
http://www.sciencedirect.com/science/article/B6VCT-4V2NP15-3/2/d7165e5aea8c81ecb801081b6552b594
Çetin, Meral
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:640-6462009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:640-646
article
Using local search to find MSSes and MUSes
In this paper, a new complete technique to compute Maximal Satisfiable Subsets (MSSes) and Minimally Unsatisfiable Subformulas (MUSes) of sets of Boolean clauses is introduced. The approach improves the currently most efficient complete technique in several ways. It makes use of the powerful concept of critical clause and of a computationally inexpensive local search oracle to boost an exhaustive algorithm proposed by Liffiton and Sakallah. These features can allow exponential efficiency gains to be obtained. Accordingly, experimental studies show that this new approach outperforms the best current existing exhaustive ones.
SAT MSSes MUSes Satisfiability Hybrid algorithm
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-2/2/6630d1e72376dc16e1ea87bca1e6d617
Grégoire, Éric
Mazure, Bertrand
Piette, Cédric
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:604-6102009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:604-610
article
Objective comparisons of the optimal portfolios corresponding to different utility functions
This paper considers the effects of some frequently used utility functions in portfolio selection by comparing the optimal investment outcomes corresponding to these utility functions. Assets are assumed to form a complete market of the Black-Scholes type. Under consideration are four frequently used utility functions: the power, logarithm, exponential and quadratic utility functions. To make objective comparisons, the optimal terminal wealths are derived by integration representation. The optimal strategies which yield optimal values are obtained by the integration representation of a Brownian martingale. The explicit strategy for the quadratic utility function is new. The strategies for other utility functions such as the power and the logarithm utility functions obtained this way coincide with known results obtained from Merton's dynamic programming approach.
Utility function Optimal portfolio Martingale measure Integration representation Brownian martingales
http://www.sciencedirect.com/science/article/B6VCT-4V42J7B-3/2/52207dae8a5fcd202a6d6226617602a6
Yu, Bosco Wing-Tong
Pang, Wan Kai
Troutt, Marvin D.
Hou, Shui Hung
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:315-3222009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:315-322
article
A tighter variant of Jensen's lower bound for stochastic programs and separable approximations to recourse functions
In this paper, we propose a new method to compute lower bounds on the optimal objective value of a stochastic program and show how this method can be used to construct separable approximations to the recourse functions. We show that our method yields tighter lower bounds than Jensen's lower bound and it requires a reasonable amount of computational effort even for large problems. The fundamental idea behind our method is to relax certain constraints by associating dual multipliers with them. This yields a smaller stochastic program that is easier to solve. We particularly focus on the special case where we relax all but one of the constraints. In this case, the recourse functions of the smaller stochastic program are one dimensional functions. We use these one dimensional recourse functions to construct separable approximations to the original recourse functions. Computational experiments indicate that our lower bounds can significantly improve Jensen's lower bound and our recourse function approximations can provide good solutions.
Stochastic programming Lower bounds Recourse function approximation
http://www.sciencedirect.com/science/article/B6VCT-4V1TXRD-3/2/30c748263003a072afb1037e009d8e47
Topaloglu, Huseyin
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:209-2182009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:209-218
article
Efficiency decompositions for heterogeneous technologies
This paper examines firms operating under different technologies but under a common metatechnology and provides a decomposition of their efficiency into input-invariant and output-invariant components. To achieve this, it reviews known definitions of technical and scale efficiency and provides alternative expressions, which incorporate a firm operating at the most productive scale size. By extending this approach, analogous decompositions are derived for the gap between two technologies and the (technical) efficiency difference between two firms operating under two distinct technologies or metatechnologies. Two indicative case-studies are also presented in order to illustrate the applicability of the proposed framework.
Production efficiency Most productive scale size Data envelopment analysis
http://www.sciencedirect.com/science/article/B6VCT-4V0TD2N-2/2/f3db6856ee65c38b6e1bc6a1f276fe99
Kounetas, Konstantinos
Mourtos, Ioannis
Tsekouras, Konstantinos
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:697-7052009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:697-705
article
Scheduling projects with stochastic activity duration to maximize expected net present value
Although uncertainty is rife in many project management contexts, little is known about adaptively optimizing project schedules. We formulate the problem of adaptively optimizing the expected present value of a project's cash flow, and we show that it is practical to perform the optimization. The formulation includes randomness in activity durations, costs, and revenues, so the optimization leads to a recursion with a large state space even if the durations are exponentially distributed. We present an algorithm that partially exercises the "curse of dimensionality" as computational results demonstrate. Most of the paper is restricted to exponentially distributed task durations, but we sketch the adaptation of the algorithm to approximate any probability distribution of task duration.
Project scheduling Dynamic programming
http://www.sciencedirect.com/science/article/B6VCT-4TPF4FF-5/2/e9bb0abc5606418e27cc4db5b5ca8868
Sobel, Matthew J.
Szmerekovsky, Joseph G.
Tilson, Vera
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:759-7682009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:759-768
article
Optimizing product assortment under customer-driven demand substitution
The problem of product assortment and inventory planning under customer-driven demand substitution is analyzed and a mathematical model for this problem is provided in this paper. Realistic issues in a retail context such as supplier selection, shelf space constraints, and poor quality procurement are also taken into account. The performance of three modified models, one that neglects customers' substitution behavior, another that excludes supplier selection decision, and one that ignores shelf space limitations, are analyzed separately with computational experiments. The results of the analysis demonstrate that neglecting customer-driven substitution or excluding supplier selection or ignoring shelf space limitations may lead to significantly inefficient assortments. The effects of demand variability and substitution cost on optimal assortment and supplier selection decisions as well as on the optimal revenue are also investigated. The main contribution of this paper is the development of a practical and flexible model to aid retailers in finding optimal assortments to maximize the expected profit.
Retailing Inventory Demand substitution Product assortment Supplier selection
http://www.sciencedirect.com/science/article/B6VCT-4T5TPKF-4/2/6746d76eb35ac73e3c4cf79724827cde
Yücel, Eda
Karaesmen, Fikri
Salman, F. Sibel
Türkay, Metin
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:334-3382009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:334-338
article
The Hölder continuity of solutions to generalized vector equilibrium problems
In this paper, by using a weaker assumption, we discuss the Hölder continuity of solution maps for two cases of parametric generalized vector equilibrium problems under the case that the solution map is a general set-valued one, but not a single-valued one. These results extend the recent ones in the literature. Several examples are given for the illustration of our results.
Generalized vector equilibrium problems Hölder continuity Hausdorff distance Metric spaces
http://www.sciencedirect.com/science/article/B6VCT-4V8GB4J-1/2/10ccb35bd9e6cb143d4bb654a3659e1d
Li, S.J.
Li, X.B.
Wang, L.N.
Teo, K.L.
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:810-8212009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:810-821
article
Capacitated dynamic lot sizing problems in closed-loop supply chain
In this paper, we address the capacitated dynamic lot sizing problem arising in closed-loop supply chain where returned products are collected from customers. These returned products can either be disposed or be remanufactured to be sold as new ones again; hence the market demands can be satisfied by either newly produced products or remanufactured ones. The capacities of production, disposal and remanufacturing are limited, and backlogging is not allowed. A general model of this problem is formulated, and several useful properties of the problem are characterized when cost functions are concave. Moreover, this problem is analyzed and solved to optimality using dynamic programming algorithms under different scenarios. It is shown that the problem with only disposal or remanufacturing can be converted into a traditional capacitated lot sizing problem and be solved by a polynomial algorithm if the capacities are constant. A pseudo-polynomial algorithm is proposed for the problem with both capacitated disposal and remanufacturing. The problem with capacitated production and remanufacturing and the problem with uncapacitated production and capacitated remanufacturing are also analyzed and solved. Through numerical experiments we show that the proposed algorithms perform well when solving problems of practical sizes. From the experimental results also indicates that it is worthwhile to expand the remanufacturing capacity only when returned products exist in a relatively long planning horizon, and production capacities have little effect on the remanufacturing plan when the demand is mainly satisfied by the production.
Closed-loop supply chain Capacitated dynamic lot sizing problem Production Remanufacturing Disposal
http://www.sciencedirect.com/science/article/B6VCT-4TT9GH2-1/2/93aeaac17b5c9b6f35e02e02904b8908
Pan, Zhendong
Tang, Jiafu
Liu, Ou
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:979-9822009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:979-982
article
"A note on the economic lot size of the integrated vendor-buyer inventory system derived without derivatives": A comment
Wee and Chung [Wee, H.M., Chung, C.T., 2007. A note on the economic lot size of the integrated vendor-buyer inventory system derived without derivatives. European Journal of Operational Research 177, 1289-1293] use the complete squares method to locate the optimal solution of the integrated system's total cost TC(Q,Â B,Â n). However, their algebra method has shortcomings such that it may be invalid. The main purpose of this paper is to overcome those shortcomings and present complete proofs for Wee and Chung (2007).
Integrated production inventory model Backlogging Economic lot size
http://www.sciencedirect.com/science/article/B6VCT-4V0TD2N-1/2/30eb399a7c2accfac3157074bfcf85b6
Chung, Kun-Jen
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:830-8472009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:830-847
article
Selection of contract suppliers under price and demand uncertainty in a dynamic market
In this paper, we consider a supply contracting problem in which the buyer firm faces non-stationary stochastic price and demand. First, we derive analytical results to compare two pure strategies: (i) periodically purchasing from the spot market; and (ii) signing a long-term contract with a single supplier. The results from the pure strategies show that the selection of suppliers can be complicated by many parameters, and is particularly affected by price uncertainty. We then develop a stochastic dynamic programming model to incorporate mixed strategies, purchasing commitments and contract cancellations. Computational results show that increases in price (demand) uncertainty favor long-term (short-term) suppliers. By examining the two-way interactions of contract factors (price, demand, purchasing bounds, learning and technology effect, salvage values and contract cancellation), both intuitive and non-intuitive managerial insights in outsourcing strategies are derived.
Supply chain contracts Stochastic dynamic programming Purchasing Supplier selection
http://www.sciencedirect.com/science/article/B6VCT-4TN0KW2-4/2/4b68deec09d1a123b41f9c0a03c8c1e6
Li, Shanling
Murat, Alper
Huang, Wanzhen
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:452-4632009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:452-463
article
An optimization based approach for deployment of roadway incident response vehicles with reliability constraints
In recent years transportation agencies have introduced patrol based response programs to remove roadway incidents rapidly. With the evolution of technology incident detection and notification from remote traffic operation centers is possible and patrols to detect incidents are not necessary. Instead, the response units can be placed at various depots in urban areas and dispatched to incident sites upon notification. In this paper, we propose a reliability based mixed integer programming model to find best locations of incidence response depots and assign response vehicles to these depots so that incidents can be cleared efficiently at a minimum cost. The approach is unique as it considers fixed and variable costs of vehicles and depots, occurrences of major and minor incidents, and reliability of response service in the same model. Numerical results are generated for an example problem and sensitivity analysis is conducted to explore the relationships between parameters of the problem.
Transportation Facilities planning and design Optimization Incident management Emergency response
http://www.sciencedirect.com/science/article/B6VCT-4TGHNBR-1/2/2910bcd4b0312d5217e3e779d8421de0
Pal, Raktim
Bose, Indranil
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:468-4772009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:468-477
article
An axiomatic analysis of concordance-discordance relations
Outranking methods propose an original way to build a preference relation between alternatives evaluated on several attributes that has a definite ordinal flavor. Indeed, most of them appeal the concordance/non-discordance principle that leads to declaring that an alternative is "superior" to another, if the coalition of attributes supporting this proposition is "sufficiently important" (concordance condition) and if there is no attribute that "strongly rejects" it (non-discordance condition). Such a way of comparing alternatives is rather natural. However, it is well known that it may produce binary relations that do not possess any remarkable property of transitivity or completeness. This explains why the axiomatic foundations of outranking methods have not been much investigated, which is often seen as one of their important weaknesses. This paper uses conjoint measurement techniques to obtain an axiomatic characterization of preference relations that can be obtained on the basis of the concordance/non-discordance principle. It emphasizes their main distinctive feature, i.e. their very crude way to distinguish various levels of preference differences on each attribute. We focus on outranking methods, such as ELECTRE I, that produce a reflexive relation, interpreted as an "at least as good as" preference relation. The results in this paper may be seen as an attempt to give such outranking methods a sound axiomatic foundation based on conjoint measurement.
Multiple criteria analysis Concordance Discordance Outranking methods Conjoint measurement Non-transitive preferences
http://www.sciencedirect.com/science/article/B6VCT-4TYYS3X-1/2/02ec8157ab05561e05e6b59c9390b021
Bouyssou, Denis
Pirlot, Marc
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:409-4192009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:409-419
article
Supply chain design under uncertainty using sample average approximation and dual decomposition
We present a supply chain design problem modeled as a sequence of splitting and combining processes. We formulate the problem as a two-stage stochastic program. The first-stage decisions are strategic location decisions, whereas the second stage consists of operational decisions. The objective is to minimize the sum of investment costs and expected costs of operating the supply chain. In particular the model emphasizes the importance of operational flexibility when making strategic decisions. For that reason short-term uncertainty is considered as well as long-term uncertainty. The real-world case used to illustrate the model is from the Norwegian meat industry. We solve the problem by sample average approximation in combination with dual decomposition. Computational results are presented for different sample sizes and different levels of data aggregation in the second stage.
Supply chain design Stochastic programming Sample average approximation Dual decomposition
http://www.sciencedirect.com/science/article/B6VCT-4V3HHFW-1/2/53c7861a7cfc36aa57c69fc43f721973
Schütz, Peter
Tomasgard, Asgeir
Ahmed, Shabbir
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:748-7592009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:748-759
article
A stochastic dynamic traveling salesman problem with hard time windows
Just-in-time (JIT) trucking service, i.e., arriving at customers within specified time windows, has become the norm for freight carriers in all stages of supply chains. In this paper, a JIT pickup/delivery problem is formulated as a stochastic dynamic traveling salesman problem with time windows (SDTSPTW). At a customer location, the vehicle either picks up goods for or delivers goods from the depot, but does not provide moving service to transfer goods from one location to another. Such routing problems are NP-hard in deterministic settings, and in our context, complicated further by the stochastic, dynamic nature of the problem. This paper develops an efficient heuristic for the SDTSPTW with hard time windows. The heuristic is shown to be useful both in controlled numerical experiments and in applying to a real-life trucking problem.
Traveling salesman problem Just-in-time Time windows Stochastic, dynamic network
http://www.sciencedirect.com/science/article/B6VCT-4TTMNBR-1/2/765f76498a277b6f62a6f56051963f75
Chang, Tsung-Sheng
Wan, Yat-wah
OOI, Wei Tsang
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:89-972009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:89-97
article
Improving benders decomposition using a genetic algorithm
We develop and investigate the performance of a hybrid solution framework for solving mixed-integer linear programming problems. Benders decomposition and a genetic algorithm are combined to develop a framework to compute feasible solutions. We decompose the problem into a master problem and a subproblem. A genetic algorithm along with a heuristic are used to obtain feasible solutions to the master problem, whereas the subproblem is solved to optimality using a linear programming solver. Over successive iterations the master problem is refined by adding cutting planes that are implied by the subproblem. We compare the performance of the approach against a standard Benders decomposition approach as well as against a stand-alone solver (Cplex) on MIPLIB test problems.
Genetic algorithm Benders decomposition Mixed-integer linear programs
http://www.sciencedirect.com/science/article/B6VCT-4TX793S-1/2/6a935ef7632fc3f10dec608a892626b6
Poojari, C.A.
Beasley, J.E.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:470-4792009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:470-479
article
Robust improvement schemes for road networks under demand uncertainty
This paper is concerned with development of improvement schemes for road networks under future travel demand uncertainty. Three optimization models, sensitivity-based, scenario-based and min-max, are proposed for determining robust optimal improvement schemes that make system performance insensitive to realizations of uncertain demands or allow the system to perform better against the worst-case demand scenario. Numerical examples and simulation tests are presented to demonstrate and validate the proposed models.
Transportation Network design Uncertainty modelling Robustness and sensitivity analysis
http://www.sciencedirect.com/science/article/B6VCT-4THJGKB-1/2/a27546704ef60c111c7a0c45858f8ee8
Yin, Yafeng
Madanat, Samer M.
Lu, Xiao-Yun
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:734-7432009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:734-743
article
A queueing model of delayed product differentiation
We consider a production system in which a supplier produces semi-finished items on a make-to-stock basis for a manufacturer that will customize the items on a make-to-order basis. The proportion of total processing time undertaken by the supplier determines how suitable the semi-finished items will be to meet customer demand. The manufacturer wishes to determine the optimal point of differentiation (the proportion of processing completed by the supplier) and its optimal semi-finished goods buffer size. We use matrix geometric methods to evaluate various performance measures for this system, and then, with enumeration techniques, obtain optimal solutions. We find that delayed product differentiation is attractive when the manufacturer can balance the costs of customer order fulfillment delay with the costs associated with unsuitable items.
Delayed product differentiation Point of differentiation MTO queues Matrix geometric method
http://www.sciencedirect.com/science/article/B6VCT-4T5TPKF-1/2/72c18ce044f1874eec6c332777510dd0
Jewkes, Elizabeth M.
Alfa, Attahiru S.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:793-8002009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:793-800
article
Integration of business function models into an aggregate enterprise systems model
Introduced are methods that combine models of distinct business functions into an aggregate model of an enterprise system to assist management's strategic decision making. Models of individual business functions are reviewed, and equations quantifying relationships presented. Using methods of system theory, including block diagrams, non-dimensionalization, and state equation methods, these business function sub-models were assembled into a composite enterprise systems model. The formulated aggregate model is illustrated with industry examples for tire companies; nonetheless the aggregate model can be used to assess other industries. Values of parameters for the system model were determined from data obtained from annual reports of publicly owned companies. Simulations closely matched the companies' published performance over ensuing years. The developed aggregate enterprise model has significant predictive capabilities for modern corporations.
System integration Model development Supply chain strategy Operations management Complexity
http://www.sciencedirect.com/science/article/B6VCT-4T6CTMN-2/2/f6e4f5963f76c9012d91fb5f17b69835
Temponi, Cecilia
Bryant, Michael D.
Fernandez, Benito
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:553-5602009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:553-560
article
A compromised large-scale neighborhood search heuristic for capacitated air cargo loading planning
Cost effectiveness is central to the air freight forwarders. In this work, we study how an air freight forwarder should plan its cargo loading in order to minimize the total freight cost given a limited number of rented containers. To solve the problem efficiently for practical implementation, we propose a new large-scale neighborhood search heuristic. The proposed large-scale neighborhood relaxes the subset-disjoint restriction made in the existing literature; the relaxation risks a possibility of infeasible exchanges while at the same time it avoids the potentially large amount of checking effort required to enforce the subset-disjoint restriction. An efficient procedure is then used to search for improvement in the neighborhood. We have also proposed a subproblem to address the difficulties caused by the fixed charges. The compromised large-scale neighborhood (CLSN) search heuristic has shown stably superior performance when compared with the traditional large-scale neighborhood search and the mixed integer programming model.
Cargo loading problem Large-scale neighborhood search Heuristics Decision support systems
http://www.sciencedirect.com/science/article/B6VCT-4V3542H-2/2/d5e4c4a400cbec94ab3146b8abaf8cc0
Li, Yanzhi
Tao, Yi
Wang, Fan
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:908-9212009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:908-921
article
A new partial pooling structure for spare parts networks
Motivated by real-life spare parts networks, we introduce a new spare parts inventory model with lateral transshipment. We consider a multi-item, multi-location, single-echelon system with base stock control and aggregate mean waiting time constraints. The local warehouses are divided into two types: main and regular local warehouses. Lateral transshipment is allowed from main local warehouses only. A practical advantage of this structure is that only a limited number of local warehouses has to be equipped to provide lateral transshipment. This structure represents a new form of partial pooling, with no pooling (zero main locals) and full pooling (zero regular locals) as special cases. We develop an accurate and fast approximate evaluation method, and exploit this method in a heuristic procedure for the base stock level determination. We show that only a small number of main locals is sufficient to obtain most of the full pooling benefits. We also apply our methods to case data of ASML, an original equipment manufacturer in the semiconductor supplier industry. As a result of our work ASML was able to improve spare parts planning.
Inventory Spare parts Pooling Lateral transshipment
http://www.sciencedirect.com/science/article/B6VCT-4VYP94C-7/2/ced6ab1a6cfff9db1efe35dcc6b313fe
Kranenburg, A.A.
van Houtum, G.J.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:545-5562009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:545-556
article
Optimal server resource reservation policies for priority classes of users under cyclic non-homogeneous markov modeling
Resource availability optimization is studied on a server-client system where different users are partitioned into priority classes. The aim is to provide higher resource availability according to the priority of each class. For this purpose, resource reservation is modeled by a homogeneous continuous time Markov chain (CTMC), but also by a cyclic non-homogeneous Markov chain (CNHMC) as there is a cyclic behavior of the users' requests for resources. The contribution of the work presented consists in the formulation of a multiobjective optimization problem for both the above cases that aims to determine the optimal resource reservation policy providing higher levels of resource availability for all classes. The optimization problem is solved either with known methods or with a proposed kind of heuristic algorithm. Finally, explicit generalized approximate inverse preconditioning methods are adopted for solving efficiently sparse linear systems that are derived, in order to compute resource availability.
Server resources Priority classes Resource availability modeling Non-homogeneous Markov chains Optimization Approximate inverse matrix algorithms Preconditioning
http://www.sciencedirect.com/science/article/B6VCT-4TMJ3XY-2/2/a59e404f557ac9662d927b06fc983796
Koutras, V.P.
Platis, A.N.
Gravvanis, G.A.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:252-2612009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:252-261
article
Tactical level planning in float glass manufacturing with co-production, random yields and substitutable products
We investigate tactical level planning problems in float glass manufacturing. Float glass manufacturing is a process that has some unique properties such as uninterruptible production, random yields, partially controllable co-production compositions, complex relationships in sequencing of products, and substitutable products. Furthermore, changeover times and costs are very high, and production speed depends significantly on the product mix. These characteristics render measurement and management of the production capacity difficult. The motivation for this study is a real life problem faced at Trakya Cam in Turkey. Trakya Cam has multiple geographically separated production facilities. Since transportation of glass is expensive, logistics costs are high. In this paper, we consider multi-site aggregate planning, and color campaign duration and product mix planning. We develop a decision support system based on several mixed integer linear programming models in which production and transportation decisions are made simultaneously. The system has been fully implemented, and has been in use at Trakya Cam since 2005.
Float glass manufacturing OR in tactical planning Decision support systems Integer programming
http://www.sciencedirect.com/science/article/B6VCT-4V2HKGR-2/2/2d4d32d69feed526bb1f98ed7e429173
Caner TaskIn, Z.
Tamer Ünal, A.
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:848-8582009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:848-858
article
Asymptotic formulas for the derivatives of probability functions and their Monte Carlo estimations
One of the key problems in chance constrained programming for nonlinear optimization problems is the evaluation of derivatives of joint probability functions of the form . Here is the vector of physical parameters, is a random vector describing the uncertainty of the model, is the constraints mapping, and is the vector of constraint levels. In this paper specific Monte Carlo tools for the estimations of the gradient and Hessian of P(x) are proposed when the input random vector [Lambda] has a multivariate normal distribution and small variances. Using the small variance hypothesis, approximate expressions for the first- and second-order derivatives are obtained, whose Monte Carlo estimations have low computational costs. The number of calls of the constraints mapping g for the proposed estimators of the gradient and Hessian of P(x) is only 1+2Nx+2N[Lambda]. These tools are implemented in penalized optimization routines adapted to stochastic optimization, and are shown to reduce the computational cost of chance constrained programming substantially.
Applied probability Monte Carlo methods Stochastic programming Optimization with constraints Random constraints
http://www.sciencedirect.com/science/article/B6VCT-4TKPVC6-6/2/b38ea26bc754444d187da0517cf742a9
Garnier, Josselin
Omrane, Abdennebi
Rouchdy, Youssef
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:891-8982009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:891-898
article
Calculation of output characteristics of a priority queue through a busy period analysis
In this paper, we analyze some output characteristics of a discrete-time two-class priority queue by means of probability generating functions. Therefore, we construct a Markov chain which - after analysis - provides a.o. the probability generating functions of the lengths of the busy periods of both classes. It is furthermore shown how performance measures, related to the output process, are calculated from these functions. The queueing model is kept fairly simple to explain the method of analysis of the busy periods and the output characteristics of priority queues as clearly as possible.
Queueing Priority scheduling Output process Busy period analysis
http://www.sciencedirect.com/science/article/B6VCT-4V1KMNV-1/2/cffb1a6b50ea217a8484603bb727450c
Walraevens, Joris
Fiems, Dieter
Wittevrongel, Sabine
Bruneel, Herwig
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:610-6172009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:610-617
article
An integrated operation module for individual risk management
In this study, we used the cumulative prospect theory to propose the individual risk management process (IRM) which includes risk analysis and risk response stages. According to an individual's preferential structure, the process has been developed into an operational module which includes two sub-modules. From this, the individual's risk level for the confronted risk can be identified from the risk analysis, while the response strategies can be assessed at the risk response stage. Therefore, optimal response strategies can be recommended based on individual risk tolerance levels. The applicability of the proposed module is evaluated using an A-C court case. The results show that the proposed method can provide more useful and pertinent information than the traditional method of decision tree by using the expected monetary value (EMV).
IRM Preference structure Cumulative prospect theory Risk analysis Risk response
http://www.sciencedirect.com/science/article/B6VCT-4TN0KW2-3/2/792d36cd9bf1d0f289eaae06c9dfe077
Wang, Hsiao-Fan
Hsu, Fei-Chen
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:706-7222009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:706-722
article
An MILP for scheduling problems in an FMS with one vehicle
This paper concerns the mathematical formulation and optimal solutions for the Flexible Manufacturing Systems Scheduling Problem (FMSSP) with one vehicle. This linear formulation differs from the previously published ones as it takes into account the maximum number of jobs allowed in the system, limited input/output buffer capacities, empty vehicle trips and no-move-ahead trips simultaneously. Our objective is to propose optimal solutions for small and medium-sized instances and to examine a number of commonly used assumptions and heuristics. Computational experiments are carried out on instances adapted from Bilge and Ulusoy [Bilge, Ü., Ulusoy, G., 1995. A time window approach to simultaneous scheduling of machines and material handling system in an FMS. Operations Research 43, 1058-1070] and the following heuristics are evaluated: FIFO (First In First Out) rules for input/output buffer management; and FIFO, SPT (Shortest Processing Time), STT (Shortest Travel Time) and MOQS (Maximum Outgoing Queue Size) rules concerning the vehicle. The consequences of classical assumptions are also studied: ignoring empty trips, ignoring no-move-ahead constraints, and ignoring vehicle-disjunction constraints. The numerical experiments provide a set of optimal solutions and allow to evaluate the performances of heuristic search schemes.
FMS Vehicle MILP Scheduling Job-shop
http://www.sciencedirect.com/science/article/B6VCT-4SSG4VH-2/2/544e75b3149574c3751d9053a8bc21a8
Caumond, A.
Lacomme, P.
Moukrim, A.
Tchernev, N.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:801-8022009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:801-802
article
Feature cluster: Facilitated problem structuring and decision analysis (EURO 2007)
http://www.sciencedirect.com/science/article/B6VCT-4W04KHG-1/2/49278070dd3c6648641f28471bbaa71b
Franco, Alberto
Jablonsky, Josef
Leopold-Wildburger, Ulrike
Montibeller, Gilberto
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:741-7472009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:741-747
article
Theoretical and algorithmic results for a class of hierarchical fleet mix problems
In this paper a workforce model is studied from both a theoretical and an algorithmic point of view. In the considered hierarchical model workforce units can be substituted by higher qualified ones; external workforce can also be hired to cover low qualified jobs. An exact recursive solution algorithm is proposed to solve the problems and its efficiency is improved by means of cut conditions and discrete convexity properties. Finally, the results of a computational test are provided.
Discrete programming Discrete convexity Optimal fleet mix
http://www.sciencedirect.com/science/article/B6VCT-4TP49MX-1/2/8ee0703c7ceeb844fa2929c8c6f092db
Cambini, Riccardo
Riccardi, Rossana
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:769-7802009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:769-780
article
Effects of constrained supply and price contracts on agricultural cooperatives
Planning strategies depend in part on the supply flow structure of a supply chain. In food supply chains, many firms are constrained by raw material supply (e.g. vegetables and milk). This paper first examines the economic consequences of constrained supply in agricultural cooperatives. Secondly, it deals with the effects of adding price contracts to the current cooperative contract. This model combines an inventory policy approach and a Monte-Carlo simulation, to take into account price uncertainty. We illustrate our results using the case of a dairy cooperative.
Inventory Price contracts Food supply chain Agricultural cooperatives
http://www.sciencedirect.com/science/article/B6VCT-4TG28YW-1/2/098710bf3841f30d3c3ee2818158a3f1
Hovelaque, Vincent
Duvaleix-Tréguer, Sabine
Cordier, Jean
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:666-6742009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:666-674
article
Using store level scanner data to improve category management decisions: Developing positioning maps
This paper provides evidence of the usefulness of aggregated point-of-sale scanner data to infer the positioning of competing brands, providing valuable information for category management and hence facilitating decision making. Specifically, the authors propose a methodology to study the internal market structure based on market share models with latent heterogeneity when only macro-level time series data (not individual choices) are available. The proposed approach assumes a multidimensional decomposition, latent in the preference structure that is implicit to these types of models. By empirically applying this approach, the authors (1) simultaneously identify both latent dimensions of competing brands and latent segments with different brand preferences, (2) explain the competitive positioning of brands without using disaggregated consumer panel data, and (3) achieve greater predictive performance. The findings offer insights to academics and practitioners interested in improving the practice of category management.
Marketing Management Decision making Market response models Internal analysis of the market structure Positioning maps
http://www.sciencedirect.com/science/article/B6VCT-4TSD9DY-3/2/671dd994f3baa88e6ca88f4c5fa6fcf5
González-Benito, Óscar
Martínez-Ruiz, María Pilar
Mollá-Descals, Alejandro
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:773-7892009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:773-789
article
The impact of dynamic pricing on the economic order decision
This paper analyzes the impact of dynamic pricing on the single product economic order decision of a monopolist retailer. Items are procured from an external supplier according to the economic order quantity (EOQ) model and are sold to customers on a single market without competition following the simple monopolist pricing problem. Coordinated decision making of optimal pricing and ordering is influenced by operating costs - including ordering and inventory holding costs - and the demand rate obtained from a price response function. The retailer is allowed to vary the selling price, either in a fixed number of discrete points in time or continuously. While constant and continuous pricing have received much attention in the literature, problems with a limited number of price changes are rather rare. This paper illustrates the benefit of dynamically changing prices to achieve operational efficiency in the EOQ model, that is to trigger high demand rates when inventories are high. We provide structural properties of the optimal time instants when the price should be changed. Taking into account costs for changes in price, it provides numerical guidance on number, timing, and size of price changes during an order cycle. Numerical examples show that the benefits of dynamic pricing in an EOQ framework can be achieved with only a few price changes and that products being unprofitable under static pricing may become profitable under dynamic pricing.
Dynamic pricing EOQ Procurement-inventory policies Marketing-operations interface
http://www.sciencedirect.com/science/article/B6VCT-4TTMNBR-3/2/a1473c81d71f9288d55f95f91fdb0f0d
Transchel, Sandra
Minner, Stefan
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:936-9432009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:936-943
article
Risk management in power markets: The Hedging value of production flexibility
Since the 1990s power markets are being restructured worldwide and nowadays electrical power is traded as a commodity. The liberalization and with it the uncertainty in gas, fuel and electrical power prices requires an effective management of production facilities and financial contracts. Thereby derivatives build essential instruments to exchange volume as well as price risks. The challenge for participants in the newly competitive market environment is how to design, price and hedge derivative contracts in particular combination with the flexibility embedded in dispatch strategies of production assets. Accordingly, an adequate basis for management and investment decisions is needed which responds to the highly complex market situation.
Electricity risk Power derivatives Dispatch management of power plants Operational flexibility Futures markets Emission trading
http://www.sciencedirect.com/science/article/B6VCT-4W32KN4-1/2/12333967aa886925ab4b9b66332262b0
Doege, Jörg
Fehr, Max
Hinz, Juri
Lüthi, Hans-Jakob
Wilhelm, Martina
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:571-5752009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:571-575
article
Convex multi-choice games: Characterizations and monotonic allocation schemes
This paper focuses on new characterizations of convex multi-choice games using the notions of exactness and superadditivity. Furthermore, level-increase monotonic allocation schemes (limas) on the class of convex multi-choice games are introduced and studied. It turns out that each element of the Weber set of such a game is extendable to a limas, and the (total) Shapley value for multi-choice games generates a limas for each convex multi-choice game.
Multi-choice games Convex games Marginal games Weber set Monotonic allocation schemes
http://www.sciencedirect.com/science/article/B6VCT-4TK479X-2/2/6f197023a54c79dfb2be6182930c8d12
Branzei, R.
Tijs, S.
Zarzuelo, J.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:162-1692009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:162-169
article
Economic selection of process mean for single-vendor single-buyer supply chain
Process mean selection for a container-filling process is an important decision in a single-vendor single-buyer supply chain. Since the process mean determines the vendor's conforming and yield rates, it influences the vendor-buyer decisions regarding the production lot size and number of shipments delivered from the vendor to buyer. It follows, therefore, that these decisions should be determined simultaneously in order to control the supply chain total cost. In this paper, we develop a model that integrates the single-vendor single-buyer problem with the process mean selection problem. This integrated model allows the vendor to deliver the produced lot to buyer in number of unequal-sized shipments. Moreover, every outgoing item is inspected, and each item failing to meet a lower specification limit is reprocessed. Further, in order to study the benefits of using this integrated model, two baseline cases are developed. The first of which considers a hierarchical model where the vendor determines the process mean and schedules of production and shipment separately. This hierarchical model is used to show the impact of integrating the process mean selection with production/inventory decisions. The other baseline case is studied in the sensitivity analysis where the optimal solution for a given process is compared to the optimal solution when the variation in the process output is negligible. The integrated model is expected to lead to reduction in reprocessing cost, minimal loss to customer due to the deviation from the optimum target value, and consequently, providing better products at reduced cost for customers. Also, a solution procedure is devised to find the optimal solution for the proposed model and sensitivity analysis is conducted to investigate the effect of the model key parameters on the optimal solution.
Targeting problem Production process Single-vendor single-buyer problem Supply chain
http://www.sciencedirect.com/science/article/B6VCT-4V0TD2N-4/2/c1f93ed50e5bbd814f2519ec4aa46d90
Darwish, M.A.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:464-4692009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:464-469
article
A tabu search heuristic for the vehicle routing problem with private fleet and common carrier
This paper describes a tabu search heuristic for a vehicle routing problem where the owner of a private fleet can either visit a customer with one of his vehicles or assign the customer to a common carrier. The owner's objective is to minimize the variable and fixed costs for operating his fleet plus the total costs charged by the common carrier. The proposed tabu search is shown to outperform the best approach reported in the literature on 34 benchmark instances with a homogeneous fleet.
Vehicle routing Private fleet Common carrier Tabu search
http://www.sciencedirect.com/science/article/B6VCT-4TGHNBR-2/2/b1e99b21c4fc3a53cbc305b08454111c
Côté, Jean-François
Potvin, Jean-Yves
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:478-4952009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:478-495
article
ELECTRE methods with interaction between criteria: An extension of the concordance index
This paper presents an extension of the comprehensive (overall) concordance index of ELECTRE methods, which takes the interaction between criteria into account. In real-world decision-aiding situations, it is reasonable to consider only the interaction between a small number of criterion pairs. Three types of interaction have been considered: mutual strengthening, mutual weakening, and antagonistic. The new concordance index correctly takes into account such types of interactions, by imposing such conditions as boundary, monotonicity, and continuity. We demonstrate that the generalized index is able to take the three types of interaction, or dependencies, between criteria into account satisfactorily, first using quasi-criteria and then using pseudo-criteria. We also examine the links between the new concordance index and the Choquet integral.
Multicriteria analysis Outranking methods Interaction between criteria Choquet integral
http://www.sciencedirect.com/science/article/B6VCT-4V2NP15-2/2/be4fec93c28f14a0aa94aa7508223ff3
Figueira, José Rui
Greco, Salvatore
Roy, Bernard
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:139-1492009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:139-149
article
Equivalence classes of problem instances for a continuous-time lot sizing and scheduling problem
In the context of a single machine, multi-item, continuous-time lot sizing and scheduling problem with a production rate alternating between the two values zero and full production rate, this paper identifies classes of equivalent problem instances which differ from one another in the way in which demand is represented. Each class contains an instance with a continuous cumulated demand function, and may contain demand functions with very different shapes, including functions with discontinuities. When approaching the problem (in order to solve it numerically, or to prove analytical results etc.), it therefore becomes possible to select, from many different representations, the problem instance which best meets the requirements of the applied method.
Scheduling Lot sizing Equivalence classes
http://www.sciencedirect.com/science/article/B6VCT-4TY459J-3/2/17f7515361a954e4a62df1cf12ae34a7
Weidenhiller, Andreas
Jodlbauer, Herbert
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:658-6642009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:658-664
article
Heuristics for the 0-1 multidimensional knapsack problem
Two heuristics for the 0-1 multidimensional knapsack problem (MKP) are presented. The first one uses surrogate relaxation, and the relaxed problem is solved via a modified dynamic-programming algorithm. The heuristics provides a feasible solution for (MKP). The second one combines a limited-branch-and-cut-procedure with the previous approach, and tries to improve the bound obtained by exploring some nodes that have been rejected by the modified dynamic-programming algorithm. Computational experiences show that our approaches give better results than the existing heuristics, and thus permit one to obtain a smaller gap between the solution provided and an optimal solution.
Multidimensional knapsack problem Dynamic-programming Branch-and-cut Surrogate relaxation Heuristics
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-3/2/3ead967069347837788648f1a534d698
Boyer, V.
Elkihel, M.
El Baz, D.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:511-5192009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:511-519
article
Controlled sequential factorial design for simulation factor screening
Screening experiments are performed to eliminate unimportant factors efficiently so that the remaining important factors can be studied more thoroughly in later experiments. This paper proposes controlled sequential factorial design (CSFD) for discrete-event simulation experiments. It combines a sequential hypothesis testing procedure with a traditional (fractional) factorial design to control the Type I error and power for each factor under heterogeneous variance conditions. We compare CSFD with other sequential screening methods with similar error control properties. CSFD requires few assumptions and demonstrates robust performance with different system conditions. The method is appropriate for systems with a moderate number of factors and large variances.
Simulation Computer experiments Design of experiments Factor screening Sequential factorial design
http://www.sciencedirect.com/science/article/B6VCT-4TF2J2P-2/2/fb6803a1c2f9e025fbd436ee36b0fb3f
Shen, Hua
Wan, Hong
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:723-7312009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:723-731
article
Calculating safety stocks for assembly systems with random component procurement lead times: A branch and bound algorithm
In this paper, a discrete single-level multi-component inventory control model for assembly systems with random component procurement lead times is considered. The economic order quantity (EOQ) policy is used for a type of finished product. The requirements of the components are constant and cyclic (periodic), and their values per period are deduced from the EOQ for the finished product. The paper focuses on the components safety stock calculation. The objective is to minimise the average holding cost of the components while keeping the desired service level for the finished product. For this, an upper bound, two lower bounds, two dominance properties and an efficient branch and bound algorithm are suggested. Several tests are executed and conclusions are drawn. The proposed model provides a substantial saving for assembly systems with a large number and unreliable delivery of components as in semi-conductor and automotive industries.
Supply chain management Inventory Uncertainty modelling Combinatorial optimization Branch and bound
http://www.sciencedirect.com/science/article/B6VCT-4SSG4VH-3/2/62768c7548af6fb2d669c6d96ed5da3e
Louly, Mohamed-Aly Ould
Dolgui, Alexandre
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:618-6252009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:618-625
article
Information acquisition in new product introduction
In the presence of huge losses from unsuccessful new product introductions, companies often seek forecast information from various sources. As the information can be costly, companies need to determine how much effort to put into acquiring the information. Such a decision is strategically important because an insufficient investment may cause lack of knowledge of product profitability, which in turn may lead to introducing a loss-making product or scrapping a potentially profitable one. In this paper, we use decision analytical models to study information acquisition for new product introduction. Specifically, we consider a decision maker (DM) who, prior to introducing a new product, can purchase forecasts and use the information to update his knowledge of the market demand. We analyze and compare two approaches: The first approach is to determine the total amount of forecasts to purchase all at once. The second one is to purchase forecasts sequentially and, based on the purchased forecasts, determine whether those forecasts are informative enough for making an introduction decision or an additional forecast is needed. We present dynamic programming formulations for both approaches and derive the optimal policies. Via a numerical study, we find the second approach, i.e., purchasing forecasts sequentially, can generate a significant profit advantage over the first one when (1) the cost of acquiring forecasts is neither too high nor too low, (2) the precision of the forecasts is of a moderate level, and (3) the profit margin of the new product is small.
Decision analysis Dynamic programming Forecasting Marketing Production
http://www.sciencedirect.com/science/article/B6VCT-4TKPVC6-5/2/08441974c2da1a4a04c187a8793d231b
Li, Yongquan
Zhu, Kaijie
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:561-5752009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:561-575
article
Methodological comparison between DEA (data envelopment analysis) and DEA-DA (discriminant analysis) from the perspective of bankruptcy assessment
This study compares DEA (data envelopment analysis) with DEA-DA (discriminant analysis) in terms of bankruptcy assessment. Recently, many DEA researchers propose a use of DEA as a quick-and-easy tool to assess corporate bankruptcy. Meanwhile, other DEA researchers discuss a use of DEA-DA for bankruptcy-based financial analysis. The two groups are very different from the conventional use of DEA because we have long applied DEA to the measurement of operational performance, or productivity analysis. The two research groups open up a new application area (bankruptcy-based financial assessment) for DEA. This study discusses methodological strengths and weaknesses of DEA and DEA-DA from the perspective of corporate failure. The proposed comparative analysis has the three main criteria: (a) how to handle negative data in financial variables, (b) how to handle data imbalance between default and non-default firms, and (c) how to identify a failure process over time. This study finds that DEA is a managerial tool for the initial assessment of corporate failure and DEA is useful for busy corporate leaders and financial managers. In contrast, DEA-DA is useful for researchers and individuals who are interested in the detailed assessment of bankruptcy and its failure process in a time horizon.
DEA Discriminant analysis Finance Bankruptcy
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-4/2/2ba0096dfc0facab13d5a19f405a3533
Sueyoshi, Toshiyuki
Goto, Mika
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:447-4512009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:447-451
article
An optimal solution for the stochastic version of the Wagner-Whitin dynamic lot-size model
We present an algorithm for determining the optimal solution over the entire planning horizon for the dynamic lot-size model where demand is stochastic and non-stationary. The optimal solution to the deterministic problem is the well-known Wagner-Whitin algorithm. The present work contributes principally to knowledge building and provides a tool for researchers. One potentially useful contribution to practice is the solution to an important special case, where demand follows normal distributions. Other contributions to practice will likely flow from the development of improved heuristics and the improved basis to evaluate heuristic performance.
Production Inventory Optimal policies Finite horizon Dynamic programming
http://www.sciencedirect.com/science/article/B6VCT-4TDC0D4-2/2/a741fcdafd8d03813c8f284a53426434
Vargas, Vicente
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:909-9212009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:909-921
article
Sensitivity analysis of the combined travel demand model with applications
The conventional sequential four-step procedure of travel demand forecasting has been widely adopted by practitioners. However, it suffers from inconsistent consideration of travel times and congestion effects in various steps of the procedure. A combined travel demand model overcomes the problems associated with the sequential four-step procedure by integrating travel-destination-mode-route choice together. In this paper, a standard sensitivity analysis for non-linear programming is employed for conducting the sensitivity analysis of the combined travel demand model. Explicit expressions of the derivatives of model variables with respect to perturbations of input variables and parameters of the combined travel demand model are developed. These derivatives could be used to assess changes in solution variables and various system performance measures when the network characteristics are changed slightly. To gain insight into the usefulness of the sensitivity expressions, five applications, such as identification of critical parameters, paradox analysis, access control, destination choice, and error and uncertainty analysis, are presented with numerical results.
Travel demand model Four-step travel demand model Combined travel demand model Traffic equilibrium Sensitivity analysis Non-linear program
http://www.sciencedirect.com/science/article/B6VCT-4TTMJS1-1/2/3ebacaaca4852cf0d6d3b01e3100aa46
Yang, Chao
Chen, Anthony
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:867-8772009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:867-877
article
Real options approach-based demand forecasting method for a range of products with highly volatile and correlated demand
To achieve a competitive edge needed for marketing highly competitive products, modern enterprises have actively sought to provide the marketplace with an expansive range of products with high random volatility of demand and correlations between demands of product. Consequently, traditional forecasting methods for separately forecasting demand for these products are likely to yield significant deviations. Therefore, this study develops a real options approach-based forecasting model to accurately predict future demand for a given range of products with highly volatile and correlated demand. Additionally, this study also proposes using Monte Carlo simulation to solve the demand forecasting model. The real options approach associated with Monte Carlo simulation not only deals effectively with random variation involving a particular demand stochastic diffusion process, but can handle the correlations in product demand.
Demand forecasting Demand correlation Real options approach Monte Carlo simulation
http://www.sciencedirect.com/science/article/B6VCT-4TPF4FF-3/2/8631a53d6e0467776694bc9008073d6a
Huang, Ming-Guan
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:349-3582009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:349-358
article
Distributed supply chain management using ant colony optimization
Successful supply chain management requires a cooperative integration between all the partners in the network. At the operational level, the partners individual behavior should be optimal and therefore their activities have to be planned using sophisticated optimization tools. However, these tools should take into account the planning of the remaining partners, through the exchange of information, in order to allow some kind of cooperation between the elements of the chain. This paper introduces a new supply chain management technique, based on modeling a generic supply chain with suppliers, logistics and distributers, as a distributed optimization problem. The different operational activities are solved by the optimization meta-heuristic called ant colony optimization, which allows the exchange of information between different optimization problems by means of a pheromone matrix. The simulation results show that the new methodology is more efficient than a simple decentralized methodology for different instances of a supply chain.
Ant colony optimization Distributed optimization Supply chain management Logistics and operations management
http://www.sciencedirect.com/science/article/B6VCT-4V1TXRD-1/2/40d8786aa8015fbdda11d72f0e827d18
Silva, C.A.
Sousa, J.M.C.
Runkler, T.A.
Sá da Costa, J.M.G.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:480-4902009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:480-490
article
The impact of order batching and picking area zoning on order picking system performance
This paper proposes an approximation model based on queuing network theory to analyze the impact of order batching and picking area zoning on the mean order throughput time in a pick-and-pass order picking system. The model includes the sorting process needed to sort the batch again by order. Service times at pick zones are assumed to follow general distributions. The first and second moments of service times at zones and the visiting probability of a batch of orders to a pick zone are derived. Based on this information, the mean throughput time of an arbitrary order in the order picking system is obtained. Results from a real application and simulation show that this approximation model provides acceptable accuracy for practical purposes. Furthermore, the proposed method is simple and fast and can be easily applied in the design and selection process of order picking systems.
Queueing Stochastic processes Simulation Applied probability
http://www.sciencedirect.com/science/article/B6VCT-4TGS7F8-1/2/a51e5e9bdfce523c9c4a78fd5faf38dd
Yu, Mengfei
de Koster, René B.M.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:55-672009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:55-67
article
Scheduling interfering job sets on parallel machines
We consider bicriteria scheduling on identical parallel machines in a nontraditional context: jobs belong to two disjoint sets, and each set has a different criterion to be minimized. The jobs are all available at time zero and have to be scheduled (non-preemptively) on m parallel machines. The goal is to generate the set of all non-dominated solutions, so the decision maker can evaluate the tradeoffs and choose the schedule to be implemented. We consider the case where, for one of the two sets, the criterion to be minimized is makespan while for the other the total completion time needs to be minimized. Given that the problem is NP-hard, we propose an iterative SPT-LPT-SPT heuristic and a bicriteria genetic algorithm for the problem. Both approaches are designed to exploit the problem structure and generate a set of non-dominated solutions. In the genetic algorithm we use a special encoding scheme and also a unique strategy - based on the properties of a non-dominated solution - to ensure that all parts of the non-dominated front are explored. The heuristic and the genetic algorithm are compared with a time-indexed integer programming formulation for small and large instances. Results indicate that the both the heuristic and the genetic algorithm provide high solution quality and are computationally efficient. The heuristics proposed also have the potential to be generalized for the problem of interfering job sets involving other bicriteria pairs.
Interfering job sets Parallel machines Bicriteria scheduling
http://www.sciencedirect.com/science/article/B6VCT-4TYJTYS-2/2/9484d30cf8ffeb92862c3bcee35fd2af
Balasubramanian, Hari
Fowler, John
Keha, Ahmet
Pfund, Michele
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:576-5942009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:576-594
article
DEA-DA for bankruptcy-based performance assessment: Misclassification analysis of Japanese construction industry
This study describes a practical use of Data Envelopment Analysis-Discriminant Analysis (DEA-DA) for bankruptcy-based performance assessment. DEA-DA is useful for classifying non-default and default firms based upon their financial performance. However, when we apply DEA-DA to a data set on corporate bankruptcy, we usually face three problems. First, there is a sample imbalance problem because the number of default firms is often limited. In contrast, we can easily obtain a large number of non-default firms. Second, there is a computational problem to deal with a large data set. We need to consider a computational strategy to reduce the dimension of a large data set. Finally, we need to consider data alignment because the location of default firms may exist within that of non-default firms. This study discusses a simultaneous occurrence of the three problems from the perspective of Japanese industrial policy on construction business. To handle the three problems, this study combines DEA-DA with principal component analysis to reduce the computational burden and then alters DEA-DA weights to address both the sample imbalance problem and the location problem. This study also discusses a combined use between DEA-DA and rank sum tests to examine statistically hypotheses related to bankruptcy assessment. As an important application, we apply the proposed approach to the Japanese construction industry and discuss why many Japanese construction firms are misclassified.
DEA Discriminant Analysis Finance Japanese industrial policy
http://www.sciencedirect.com/science/article/B6VCT-4V3HF9M-2/2/ec590c9fa58c7889a4ab5516a27967ef
Sueyoshi, Toshiyuki
Goto, Mika
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:601-6032009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:601-603
article
A note on "Optimal resource allocation for security in reliability systems"
In a recent paper by Azaiez and Bier [Azaiez, M.N., Bier, V.M., 2007. Optimal resource allocation for security in reliability systems. European Journal of Operational Research 181, 773-786], the problem of determining resource allocation in series-parallel systems (SPSs) is considered. The results for this problem are based on the results for the least-expected cost failure-state diagnosis problem. In this note, it is demonstrated that the results for the least-expected cost failure-state diagnosis problem for SPSs in Azaiez and Bier (2007) are incorrect. In addition relevant results that were not cited in the paper are summarized.
Sequential testing Series-parallel systems
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-5/2/1d1df31b86859bf778c7343af68e4ba2
Ünlüyurt, Tonguç
Boros, Endre
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:702-7052009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:702-705
article
Minimizing the number of machines for minimum length schedules
In this paper, we present a new objective function for scheduling on parallel machines: minimizing the number of machines for schedules of minimum length. We study its complexity and we prove the NP-completeness of this problem, even if there is no precedences or for unitary execution times. We propose several polynomial algorithms for various particular cases.
Parallel scheduling Complexity Minimum number of processors
http://www.sciencedirect.com/science/article/B6VCT-4SSG4VH-1/2/05898e8f826bf49b8d40d4bc9e301614
Finke, Gerd
Lemaire, Pierre
Proth, Jean-Marie
Queyranne, Maurice
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:68-762009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:68-76
article
On the computation of all supported efficient solutions in multi-objective integer network flow problems
This paper presents a new algorithm for identifying all supported non-dominated vectors (or outcomes) in the objective space, as well as the corresponding efficient solutions in the decision space, for multi-objective integer network flow problems. Identifying the set of supported non-dominated vectors is of the utmost importance for obtaining a first approximation of the whole set of non-dominated vectors. This approximation is crucial, for example, in two-phase methods that first compute the supported non-dominated vectors and then the unsupported non-dominated ones. Our approach is based on a negative-cycle algorithm used in single objective minimum cost flow problems, applied to a sequence of parametric problems. The proposed approach uses the connectedness property of the set of supported non-dominated vectors/efficient solutions to find all integer solutions in maximal non-dominated/efficient facets.
Multi-objective linear and integer programming Multi-objective network flows Negative-cycle algorithms Parametric programming
http://www.sciencedirect.com/science/article/B6VCT-4TW6HR9-2/2/239c59315dd3f1ca59d5dabbf9eb884a
Eusébio, Augusto
Figueira, José Rui
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:370-3772009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:370-377
article
Up- and downgrading the 1-center in a network
We study budget constrained network improvement and degrading problems based on the vertex 1-center problem on graphs: given a graph with vertex weights and edge lengths the task is to decrease and increase the vertex weights within certain limits such that the optimal 1-center objective value with respect to the new weights is minimized and maximized, respectively. The upgrading (improvement) problem is shown to be solvable in time provided that the distance matrix is given. The downgrading 1-center problem is shown to be strongly -hard on general graphs but can be solved in time on trees. As byproduct we suggest an algorithm that solves the problem of minimizing over the upper envelope of n piecewise linear functions in time where K is the total number of breakpoints.
Combinatorial optimization Location problem Vertex center Upgrading Downgrading Network improvement Network modification Complexity Tree
http://www.sciencedirect.com/science/article/B6VCT-4THC1CX-2/2/56cd91778a69e2dc149e56d0657849da
Gassner, Elisabeth
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:512-5192009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:512-519
article
New variants of pairwise classification
Pairwise classification is the technique that deals with multi-class problems by converting them into a series of binary problems, one for each pair of classes. Typically, K-class classification rules tend to be easier to learn for KÂ =Â 2 than for KÂ >Â 2 - only one decision boundary requires attention. This paper presents new methods for obtaining class membership probability estimates for multi-class classification problems by coupling the probability estimates created by binary classifiers. Classifiers used include linear Bayes normal classifier, Parzen density based classifier, naive Bayes classifier, binary decision tree classifier and random neural net classifier. The accuracy of new pairwise classifiers is examined on some real data sets. The classification errors were estimated by stratified version of 10-fold cross-validation technique, i.e. the training examples were partitioned into 10 equal-sized blocks with similar class distributions as in the original set. The validation technique was repeated 10 times for each data set.
Classification by pairwise coupling Multi-class classifiers Binary classifiers
http://www.sciencedirect.com/science/article/B6VCT-4TYJTYS-3/2/924f9d8c05a7eadd67f084bc9eb333c5
Krzysko, Miroslaw
Wolynski, Waldemar
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:36-452009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:36-45
article
Transgenetic algorithm for the Traveling Purchaser Problem
In this paper an evolutionary algorithm is presented for the Traveling Purchaser Problem, an important variation of the Traveling Salesman Problem. The evolutionary approach proposed in this paper is called transgenetic algorithm. It is inspired on two significant evolutionary driving forces: horizontal gene transfer and endosymbiosis. The performance of the algorithm proposed for the investigated problem is compared with other recent works presented in the literature. Computational experiments show that the proposed approach is very effective for the investigated problem with 17 and 9 new best solutions reported for capacitated and uncapacitated instances, respectively.
Combinatorial optimization Traveling Purchaser Problem Evolutionary algorithm Transgenetic algorithm
http://www.sciencedirect.com/science/article/B6VCT-4TVTJKM-3/2/da7e91044274025fb4f7340708ef4a9b
Goldbarg, M.C.
Bagi, L.B.
Goldbarg, E.F.G.
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:420-4342009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:420-434
article
Single and multi-period optimal inventory control models with risk-averse constraints
This paper presents some convex stochastic programming models for single and multi-period inventory control problems where the market demand is random and order quantities need to be decided before demand is realized. Both models minimize the expected losses subject to risk aversion constraints expressed through Value at Risk (VaR) and Conditional Value at Risk (CVaR) as risk measures. A sample average approximation method is proposed for solving the models and convergence analysis of optimal solutions of the sample average approximation problem is presented. Finally, some numerical examples are given to illustrate the convergence of the algorithm.
Inventory control Conditional value at risk constraints Sample average approximation Stochastic programming Convex programming
http://www.sciencedirect.com/science/article/B6VCT-4V4KPT8-2/2/a875d2a44d7b7cd6f11151e766d5b2b2
Zhang, Dali
Xu, Huifu
Wu, Yue
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:531-5412009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:531-541
article
Inexact de Novo programming for water resources systems planning
This study presents an interval de Novo programming (IDNP) approach for the design of optimal water-resources-management systems under uncertainty. The model is derived by incorporating the existing interval programming and de Novo programming, allowing uncertainties represented as intervals within the optimization framework. The developed IDNP approach has the advantages in constructing optimal system design via an ideal system by introducing the flexibility toward the available resources in the system constraints. A simple numerical example is introduced to illustrate the IDNP approach. The IDNP is then applied to design an inexact optimal system with budget limit instead of finding the optimum in a given system with fixed resources in a water resources planning case. The results demonstrate that the developed method efficiently produces stable solutions under different objectives. Optimal supplies of good-quality water are obtained in considering different revenue targets of municipal-industrial-agricultural competition under a given budget.
Uncertainty Management Water resources Decision analysis Multi-objective Environment de Novo
http://www.sciencedirect.com/science/article/B6VCT-4V1KMNV-2/2/dfbdb0ab5776a2f979042378307df836
Zhang, Y.M.
Huang, G.H.
Zhang, X.D.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:695-7012009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:695-701
article
The one machine scheduling problem: Insertion of a job under the real-time constraint
We consider a single resource that performs a set of jobs, each job being defined by its operation time and its due date. Jobs are not preemptive, which means that a job that starts cannot be interrupted before completion. These jobs have been scheduled so as to minimize the total tardiness, and the schedule is known. A new job appears in the system at the current point in time that is called time 0. Its operation period and its due date are known only at the time of its appearance that is at time 0. For this particular job, the due date cannot be violated. The execution order of the jobs from the given schedule cannot be changed, but they can be postponed if needed. The objective is to insert the new job in the given schedule in order not to violate the deadline while minimizing the increase of the total tardiness resulting from the postponement of some scheduled jobs required by the insertion of the new job. A new job of the same kind appears from time to time in this system. We suppose that when a new job arises, the previous new job (if any) has been scheduled. Thus, the insertion process applies at unexpected points in time and the deadline is short, which means that this process must run in real-time. The proposed algorithm is composed of two parts: an offline part that prepares the real-time computation and an online part that runs in real-time.
Real-time Scheduling Single machine
http://www.sciencedirect.com/science/article/B6VCT-4ST3YGS-1/2/5a80b9f5468e928fa8f243e7c094d9cc
Duron, C.
Ould Louly, M.A.
Proth, J.-M.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:117-1212009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:117-121
article
Checking solvability of systems of interval linear equations and inequalities via mixed integer programming
This paper deals with the problems of checking strong solvability and feasibility of linear interval equations, checking weak solvability of linear interval equations and inequalities, and finding control solutions of linear interval equations. These problems are known to be NP-hard. We use some recently developed characterizations in combination with classical arguments to show that these problems can be equivalently stated as optimization tasks and provide the corresponding linear mixed 0-1 programming formulations.
Interval linear systems Mixed integer programming Solvability Farkas lemma
http://www.sciencedirect.com/science/article/B6VCT-4TY9MPF-2/2/cb7497d869ee911ecf1f72bb7dd0df6f
Prokopyev, Oleg A.
Butenko, Sergiy
Trapp, Andrew
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:111-1162009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:111-116
article
Two simple constant ratio approximation algorithms for minimizing the total weighted completion time on a single machine with a fixed non-availability interval
In this note, we consider the scheduling problem of minimizing the sum of the weighted completion times on a single machine with one non-availability interval on the machine under the non-resumable scenario. Together with a recent 2-approximation algorithm designed by Kacem [I. Kacem, Approximation algorithm for the weighted flow-time minimization on a single machine with a fixed non-availability interval, Computers & Industrial Engineering 54 (2008) 401-410], this paper is the first successful attempt to develop a constant ratio approximation algorithm for this problem. We present two approaches to designing such an algorithm. Our best algorithm guarantees a worst-case performance ratio of 2+[epsilon].
Single machine scheduling Machine non-availability Total weighted completion time Approximation algorithm
http://www.sciencedirect.com/science/article/B6VCT-4TX793S-2/2/5712d0a11ed2a5fba3c253850682a777
Kellerer, Hans
Kubzin, Mikhail A.
Strusevich, Vitaly A.
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:375-3842009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:375-384
article
Minimizing total tardiness on a two-machine re-entrant flowshop
We present a branch and bound algorithm for a two-machine re-entrant flowshop scheduling problem with the objective of minimizing total tardiness. In the re-entrant flowshop considered here, all jobs must be processed twice on each machine, that is, each job should be processed on machine 1, machine 2 and then machine 1 and machine 2. By regarding a job as a pair of sub-jobs, each of which represents a pass through the two machines, we develop dominance properties, a lower bound and heuristic algorithms for the problem, and use these to develop a branch and bound algorithm. For evaluation of the performance of the algorithms, computational experiments are performed on randomly generated test problems and results are reported. Results of the experiments show that the suggested branch and bound algorithm can solve problems with up to 20 sub-jobs in a reasonable amount of CPU time, and the average percentage gap of the heuristic solutions is about 13%.
Scheduling Re-entrant flowshop Branch and bound Heuristics
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-7/2/ffcfe65c3eea626bb3d7c1b4064df6df
Choi, Seong-Woo
Kim, Yeong-Dae
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:122-1292009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:122-129
article
Leadtime management in a periodic-review inventory system: A state-dependent base-stock policy
We examine a single-item, periodic-review inventory system with stochastic leadtimes, in which a replenishment order is delivered immediately or one period later, depending probabilistically on costly effort. The objective is to determine a joint inventory policy and effort-choice strategy that minimizes the expected total costs. Our analytical and computational analysis suggests that (i) a state-dependent base-stock policy is optimal, (ii) the optimal effort strategy is such that the marginal cost of effort is equal to the value of immediate delivery, and (iii) the cost impact of leadtime reduction can be very large. We also provide some counter-intuitive results, compared with the traditional multi-period newsvendor model.
Inventory Leadtime management State-dependent base-stock policy
http://www.sciencedirect.com/science/article/B6VCT-4TVJ3KV-4/2/4ae0f01a2c479901c7a9fdc4680e24ee
Lee, Jun-Yeon
Schwarz, Leroy B.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:98-1102009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:98-110
article
Adaptive sample size and importance sampling in estimation-based local search for the probabilistic traveling salesman problem
The probabilistic traveling salesman problem is a paradigmatic example of a stochastic combinatorial optimization problem. For this problem, recently an estimation-based local search algorithm using delta evaluation has been proposed. In this paper, we adopt two well-known variance reduction procedures in the estimation-based local search algorithm: the first is an adaptive sampling procedure that selects the appropriate size of the sample to be used in Monte Carlo evaluation; the second is a procedure that adopts importance sampling to reduce the variance involved in the cost estimation. We investigate several possible strategies for applying these procedures to the given problem and we identify the most effective one. Experimental results show that a particular heuristic customization of the two procedures increases significantly the effectiveness of the estimation-based local search.
Combinatorial optimization Heuristics Metaheuristics Iterative improvement algorithm Probabilistic traveling salesman problem Importance sampling
http://www.sciencedirect.com/science/article/B6VCT-4V2NP15-1/2/addac8a5957d87059a9d9e5288ce6d35
Balaprakash, Prasanna
Birattari, Mauro
Stützle, Thomas
Dorigo, Marco
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:983-9862009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:983-986
article
A note on Liu-Iwamura's dependent-chance programming
Sometimes a complex stochastic decision system undertakes multiple tasks called events, and the decision-maker wishes to maximize the chance functions which are defined as the probabilities of satisfying these events. Originally introduced by Liu and Iwamura [B. Liu, K. Iwamura, Modelling stochastic decision systems using dependent-chance programming, European Journal of Operational Research 101 (1997) 193-203], dependent-chance programming is aimed at maximizing some chance functions of events in an uncertain environment. In this work, we show that the original dependent chance-programming framework needs to be extended in order to capture an exact reliability measure for a given plan.
Inventory control Integer programming Constraint programming Demand uncertainty
http://www.sciencedirect.com/science/article/B6VCT-4TXF7XP-2/2/1c95dc881ba2cdc314819f13784dc387
Rossi, Roberto
Armagan Tarim, S.
Hnich, Brahim
Prestwich, Steven
Guran, Cahit
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:647-6572009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:647-657
article
Promoting cooperation in selfish computational grids
In distributed computing, the recent paradigm shift from centrally-owned clusters to organizationally distributed computational grids introduces a number of new challenges in resource management and scheduling. In this work, we study the problem of Selfish Load Balancing which extends the well-known load balancing (LB) problem to scenarios in which each processor is concerned only with the performance of its local jobs. We propose a simple mathematical model for such systems and a novel function for computing the cost of the execution of foreign jobs. Then, we use the game-theoretic framework to analyze the model in order to compute the expected result of LB performed in a grid formed by two clusters. We show that, firstly, LB is a socially-optimal strategy, and secondly, for similarly loaded clusters, it is sufficient to collaborate during longer time periods in order to make LB the dominant strategy for each cluster. However, we show that if we allow clusters to make decisions depending on their current queue length, LB will never be performed. Then, we propose a LB algorithm which balances the load more equitably, even in the presence of overloaded clusters. Our algorithms do not use any external forms of compensation (such as money). The load is balanced only by considering the parameters of execution of jobs. This analysis is assessed experimentally by simulation, involving scenarios with multiple clusters and heterogeneous load.
Scheduling Load balancing Game theory Grid
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-6/2/e7c890324d8029f0b701044fddee6367
Rzadca, Krzysztof
Trystram, Denis
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:675-6872009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:675-687
article
A review of Hopfield neural networks for solving mathematical programming problems
The Hopfield neural network (HNN) is one major neural network (NN) for solving optimization or mathematical programming (MP) problems. The major advantage of HNN is in its structure can be realized on an electronic circuit, possibly on a VLSI (very large-scale integration) circuit, for an on-line solver with a parallel-distributed process. The structure of HNN utilizes three common methods, penalty functions, Lagrange multipliers, and primal and dual methods to construct an energy function. When the function reaches a steady state, an approximate solution of the problem is obtained. Under the classes of these methods, we further organize HNNs by three types of MP problems: linear, non-linear, and mixed-integer. The essentials of each method are also discussed in details. Some remarks for utilizing HNN and difficulties are then addressed for the benefit of successive investigations. Finally, conclusions are drawn and directions for future study are provided.
Hopfield neural networks Energy function Mathematical programming penalty function Lagrange multiplier Primal and dual functions
http://www.sciencedirect.com/science/article/B6VCT-4TX33M3-1/2/d72424cb5d61bfab7f275593ec2a86ea
Wen, Ue-Pyng
Lan, Kuen-Ming
Shih, Hsu-Shih
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:834-8452009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:834-845
article
Structuring an MCDA model using SSM: A case study in energy efficiency
This work presents the use of a problem structuring method, Soft Systems Methodology (SSM), to structure a Multi-Criteria Decision Analysis (MCDA) model, aimed at appraising energy efficiency initiatives. SSM was useful to help defining clearly the decision problem context and the main actors involved, as well as to unveil the relevant objectives for each stakeholder. Keeney's Value Focused Thinking approach was then used to refine and structure the list of objectives according to the perspective of the main evaluators identified. In addition to describing this particular case study, this paper aims at providing some general guidelines on how SSM may facilitate the emergence of objectives for MCDA models.
Problem structuring methods Multiple criteria analysis SSM Value Focused Thinking Energy efficiency
http://www.sciencedirect.com/science/article/B6VCT-4VY78NS-4/2/9cc351c5d617b089d956bc9eb5d4f3e7
Neves, L.P.
Dias, L.C.
Antunes, C.H.
Martins, A.G.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:276-2842009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:276-284
article
A new clustering approach using data envelopment analysis
In this paper, we present a new clustering method that involves data envelopment analysis (DEA). The proposed DEA-based clustering approach employs the piecewise production functions derived from the DEA method to cluster the data with input and output items. Thus, each evaluated decision-making unit (DMU) not only knows the cluster that it belongs to, but also checks the production function type that it confronts. It is important for managerial decision-making where decision-makers are interested in knowing the changes required in combining input resources so it can be classified into a desired cluster/class. In particular, we examine the fundamental CCR model to set up the DEA clustering approach. While this approach has been carried for the CCR model, the proposed approach can be easily extended to other DEA models without loss of generality. Two examples are given to explain the use and effectiveness of the proposed DEA-based clustering method.
Data envelopment analysis Production Cluster analysis CCR model DEA-based clustering Piecewise production function
http://www.sciencedirect.com/science/article/B6VCT-4TVJ3KV-2/2/83ab4186e16d615a0a832c4e3ec9636b
Po, Rung-Wei
Guh, Yuh-Yuan
Yang, Miin-Shen
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:846-8562009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:846-856
article
Structuring resource allocation decisions: A framework for building multi-criteria portfolio models with area-grouped options
Multi-criteria portfolio modelling has been extensively employed as an effective means to allocate scarce resources for investment in projects when considering costs, benefits and risks. Some of these modelling approaches allow the grouping of projects into organisational areas, thus also supporting the decision of resource allocation among organisational units in a way that is collectively efficient for the organisation. However, structuring in practice a portfolio model using this latter type of approach is not a trivial task. How should areas be defined? Where should new projects be included? How should one define the criteria to evaluate performance? As far as we know, there is very little indication in the operational research and decision sciences literatures on how to structure this type of model. This paper suggests different ways to structuring portfolio models where projects are divided into areas and evaluated by multiple criteria, and illustrates their use in two action-research projects. Drawing on these experiences it then suggests a general framework for the structuring of such models in practice. Directions for future research are also identified.
Multi-criteria decision analysis Problem structuring Portfolio analysis Resource allocation decisions
http://www.sciencedirect.com/science/article/B6VCT-4VY78NS-5/2/06e2e49c50e1becd4f65eaea952be8a7
Montibeller, Gilberto
Franco, L. Alberto
Lord, Ewan
Iglesias, Aline
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:491-5032009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:491-503
article
The value of information in a capacitated closed loop supply chain
We explore the value of information in the context of a firm that faces uncertainty with respect to demand, product returns, recovery yield, and capacity utilization. Capacity is finite and shared between new production and recovery operations. The operational decisions of interest are the quantity of new product to produce, the quantity of returns to recover, and the quantity of returns to dispose. Product recovery is uncertain in that each returned unit can be successfully recovered with a known probability, and otherwise it is discarded at a cost. Demand in a period is satisfied with new production, recovered returns, or a mix of both types. We measure and evaluate the value of information through three information cases that separately address different types of information: demand, recovery yield, and capacity utilization. We find that there is no dominance in value amongst the different types of information, although information on capacity utilization provides the highest average value and exceeds the value of the other two types of information in 55% of the cases studied. We also identify the operating conditions in which each type of information is most valuable, compare the value of information to other types of investments, and also assess robustness with respect to the accuracy of information.
Value of information Closed loop supply chains Reverse logistics
http://www.sciencedirect.com/science/article/B6VCT-4TKPVC6-3/2/e1f28fde8e540f0e3d27dc74c86ff679
Ketzenberg, Michael
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:790-7992009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:790-799
article
A location-allocation heuristic for the capacitated multi-facility Weber problem with probabilistic customer locations
The capacitated multi-facility Weber problem is concerned with locating m facilities in the Euclidean plane, and allocating their capacities to n customers at minimum total cost. The deterministic version of the problem, which assumes that customer locations and demands are known with certainty, is a non-convex optimization problem and difficult to solve. In this work, we focus on a probabilistic extension and consider the situation where the customer locations are randomly distributed according to a bivariate distribution. We first present a mathematical programming formulation, which is even more difficult than its deterministic version. We then propose an alternate location-allocation local search heuristic generalizing the ideas used originally for the deterministic problem. In its original form, the applicability of the heuristic depends on the calculation of the expected distances between the facilities and customers, which can be done for only very few distance and probability density function combinations. We therefore propose approximation methods which make the method applicable for any distance function and bivariate location distribution.
Heuristics Expected distance Facility location-allocation Probabilistic capacitated Weber problem
http://www.sciencedirect.com/science/article/B6VCT-4TSD9DY-2/2/8f5c43dd808c68af06adc03b5f6ec17b
AltInel, I. Kuban
Durmaz, Engin
Aras, Necati
ÖzkIsacIk, Kerem Can
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:706-7142009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:706-714
article
An integer linear programming approach for approximate string comparison
We introduce a problem called maximum common characters in blocks (MCCB), which arises in applications of approximate string comparison, particularly in the unification of possibly erroneous textual data coming from different sources. We show that this problem is NP-complete, but can nevertheless be solved satisfactorily using integer linear programming for instances of practical interest. Two integer linear formulations are proposed and compared in terms of their linear relaxations. We also compare the results of the approximate matching with other known measures such as the Levenshtein (edit) distance.
Approximate string matching Distance metric Block edits Block moves Integer programming Hop constraints
http://www.sciencedirect.com/science/article/B6VCT-4TSD9DY-1/2/e3f085090ccc856d72becdfd66a7591c
Ritt, Marcus
Costa, Alysson M.
Mergen, Sergio
Orengo, Viviane M.
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:296-3022009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:296-302
article
Non-linear anonymous pricing combinatorial auctions
In combinatorial auctions the pricing problem is of main concern since it is the means by which the auctioneer signals the result of the auction to the participants. In order for the auction to be regarded as fair among the various participants the price signals should be such that a participant that has won a subset of items knows why his bid was a winning bid and that agents that have not acquired any item easily can detect why they lost. The problem in the combinatorial auction setting is that the winner determination problem is a hard integer programming problem and hence a linear pricing scheme supporting the optimal allocation might not exist. From integer programming duality theory we know that there exist non-linear anonymous price functions that support the optimal allocation. In this paper we will provide a means to obtain a simple form of a price system that supports the optimal allocation. Our method relies on the fact that we separate the solution of the winner determination problem and the pricing problem. This separation yields a non-linear price function of a much simpler form compared to when the two problems are solved simultaneously. The pure pricing problem is formulated as a mixed-integer program. The procedure is computationally tested using difficult instances of the combinatorial auctions test suite [16]. The results indicate that the number of extreme prices forming the non-linear anonymous price system is small.
Combinatorial auctions Set packing Strong duality theory Non-linear anonymous pricing
http://www.sciencedirect.com/science/article/B6VCT-4V34D72-1/2/fc3b58e32f4629469601387385eed65e
Drexl, Andreas
Jørnsten, Kurt
Knof, Diether
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:732-7332009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:732-733
article
Special Issue on Supply Chain Design
http://www.sciencedirect.com/science/article/B6VCT-4T6CTMN-4/2/d7c953d0594e21bba5223af77411c648
Rappold, James A.
Tchernev, Nikolay
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:873-8822009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:873-882
article
Interactive construction of graphical decision models based on causal mechanisms
We propose a framework for building graphical decision models from individual causal mechanisms. Our approach is based on the work of Simon [Simon, H.A., 1953. Causal ordering and identifiability. In: Hood, W.C., Koopmans, T.C. (Eds.), Studies in Econometric Method. Cowles Commission for Research in Economics. Monograph No. 14. John Wiley and Sons Inc., New York, NY, pp. 49-74 (Ch. III)], who proposed a causal ordering algorithm for explicating causal asymmetries among variables in a self-contained set of structural equations. We extend the causal ordering algorithm to under-constrained sets of structural equations, common during the process of problem structuring. We demonstrate that the causal ordering explicated by our extension is an intermediate representation of a modeler's understanding of a problem and that the process of model construction consists of assembling mechanisms into self-contained causal models. We describe ImaGeNIe, an interactive modeling tool that supports mechanism-based model construction and demonstrate empirically that it can effectively assist users in constructing graphical decision models.
Decision analysis Model building Bayesian networks Structural equation models Causal ordering
http://www.sciencedirect.com/science/article/B6VCT-4VY78NS-6/2/71b66c6dc8bb9311070346ba24ee5af5
Lu, Tsai-Ching
Druzdzel, Marek J.
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:363-3692009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:363-369
article
A new bidirectional search algorithm with shortened postprocessing
For finding a shortest path in a network bidirectional A* is a widely known algorithm. This algorithm distinguishes between the main phase and the postprocessing phase. The version of bidirectional A* that is considered the most appropriate in literature hitherto, uses a so-called balanced heuristic estimate. This type of heuristic is chosen, as it accounts for a short postprocessing phase. In this paper, we do not restrict ourselves any longer to balanced heuristics. First, we introduce an algorithm containing a new method for the postprocessing phase, reducing this phase considerably for non-balanced heuristics. For a balanced heuristic the new algorithm is nearly equivalent to the existing versions of bidirectional A*. An obvious choice for a non-balanced heuristic turns out to be superior in terms of storage space and computation time. Second, we show that the main phase on its own, when using this non-balanced heuristic estimate, is a useful algorithm, which provides us quickly with a feasible approximation.
Shortest path Road network search Bidirectional search
http://www.sciencedirect.com/science/article/B6VCT-4TMJ3XY-1/2/7760330f167efe416d22a3abba9abfd8
Pijls, Wim
Post, Henk
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:647-6542009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:647-654
article
Testing procedures for detection of linear dependencies in efficiency models
The validity of many efficiency measurement methods rely upon the assumption that variables such as input quantities and output mixes are independent of (or uncorrelated with) technical efficiency, however few studies have attempted to test these assumptions. In a recent paper, Wilson (2003) investigates a number of independence tests and finds that they have poor size properties and low power in moderate sample sizes. In this study we discuss the implications of these assumptions in three situations: (i) bootstrapping non-parametric efficiency models; (ii) estimating stochastic frontier models and (iii) obtaining aggregate measures of industry efficiency. We propose a semi-parametric Hausmann-type asymptotic test for linear independence (uncorrelation), and use a Monte Carlo experiment to show that it has good size and power properties in finite samples. We also describe how the test can be generalized in order to detect higher order dependencies, such as heteroscedasticity, so that the test can be used to test for (full) independence when the efficiency distribution has a finite number of moments. Finally, an empirical illustration is provided using data on US electric power generation.
Data envelopment analysis Correlation Independence Hypothesis test Aggregation
http://www.sciencedirect.com/science/article/B6VCT-4TBXGCV-1/2/83098f2af95f00bdf5a408f9549fb5ee
Peyrache, Antonio
Coelli, Tim
oai:RePEc:eee:ejores:v:199:y:2009:i:2:p:435-4412009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:2:p:435-441
article
Optimal information acquisition for a linear quadratic control problem
This paper develops a generalization of the linear quadratic control problem with partial information. As in the standard partial information setting, it is assumed that the state variable is only observed with noise. The idea in this paper is that the information level may be chosen optimally. In real life information is costly to acquire. It is therefore a trade off between the costs of getting detailed information and the increased value this information gives. We believe that the technique we present should have potential for application within both economics and engineering.
Dynamic programming Linear quadratic control Partial information Optimal information acquisition
http://www.sciencedirect.com/science/article/B6VCT-4V3542H-1/2/4c9ef9f7e2bfed5fabc523b1c60d55c3
Lindset, Snorre
Lund, Arne-Christian
Matsen, Egil
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:435-4462009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:435-446
article
Multi-objective evacuation routing in transportation networks
In this paper, the optimal design and analysis of evacuation routes in transportation networks is examined. An methodology for optimal egress route assignment is suggested. An integer programming (IP) formulation for optimal route assignment is presented, which utilizes M/G/c/c state dependent queueing models to cope with congestion and time delays on road links. M/G/c/c simulation software is used to evaluate performance measures of the evacuation plan: clearance time, total travelled distance and blocking probabilities. Extensive experimental results are included.
Evacuation Routing Queueing networks
http://www.sciencedirect.com/science/article/B6VCT-4TJX1SX-1/2/5ef80f4198f3b55cc23bf234caa42e78
Stepanov, Alexander
Smith, James MacGregor
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:781-7922009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:781-792
article
Designing multi-echelon service parts networks with finite repair capacity
We propose an approach to model and solve the joint problem of facility location, inventory allocation and capacity investment in a two echelon, single-item, service parts supply chain with stochastic demand. The objective of the decision problem is to minimize the total expected costs associated with (1) opening repair facilities, (2) assigning each field service location to an opened facility, (3) determining capacity levels of the opened repair facilities, and (4) optimizing inventory allocation among the locations. Due to the size of the problem, computational efficiency is essential. The accuracy of the approximations and effectiveness of the approach are analyzed with two numerical studies. The approach provides optimal results in 90% of scenarios tested and was within 2% of optimal when it did not.We explore the impact of capacity utilization, inventory availability, and lead times on the performance of the approach. We show that including tactical considerations jointly with strategic network design resulted in additional cost savings from 3% to 12%. Our contribution is the development of a practical model and approach to support the decision making process of joint facility location and multi-echelon inventory optimization.
Inventory Maintenance Queueing OR in military Stochastic processes Integer programming Non-linear programming
http://www.sciencedirect.com/science/article/B6VCT-4T6CTMN-3/2/ba4e3b9313fb3793e8dbfe0849603552
Rappold, James A.
Van Roo, Ben D.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:823-8332009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:823-833
article
Understanding problem structuring methods interventions
This article presents a conceptual framework and methodological guide for researching and understanding OR interventions particularly problem structuring methods (PSM). The article argues that OR/PSM interventions are complex events which can not be understood by traditional approaches alone. In this paper an alternative methodology is developed, where the units of analysis are the narratives and networks produced during PSM interventions. The paper outlines the main theoretical and methodological concerns that need to be appreciated in studying PSM interventions. The paper then explores actor-network theory and narrative analysis as approaches to study them. A case study describing the use of these approaches is provided.
Problem structuring methods Interventions Actor-network theory Constructionist approaches Sociology of scientific knowledge Narrative analysis
http://www.sciencedirect.com/science/article/B6VCT-4W0R0KJ-1/2/984e479b6b36e601b0a14e691fef9b4d
White, Leroy
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:150-1612009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:150-161
article
Supplier default dependencies: Empirical evidence from the automotive industry
Common ways to mitigate the detrimental consequences of supplier bankruptcies are to install redundancy and to pursue a multiple-sourcing strategy. This is based on the assumption that the adverse event of one supplier going out of business is largely independent from the default of other suppliers. However, this implicit assumption does not hold in all cases. This study - based on empirical data from automotive suppliers - reveals that default dependencies among suppliers do often exist and can have significant consequences. We use copula functions, a method of representing joint distribution functions with particular marginals, to capture the default dependence between automotive suppliers and to simulate various default dependence scenarios. We also conduct a comparative static analysis illustrating the significant impact of default correlation in a supplier portfolio. Our findings should spur managers to analyze their supplier portfolios with respect to default dependencies, and to take this phenomenon into consideration when making sourcing decisions.
Supply chain management Supplier default Sourcing strategy Supplier portfolio Default dependence Copulas
http://www.sciencedirect.com/science/article/B6VCT-4TYYS3X-2/2/d5871d1c25bb623034e30b7a1f2663f4
Wagner, Stephan M.
Bode, Christoph
Koziol, Philipp
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:170-1752009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:170-175
article
Calculation of delay characteristics for multiserver queues with constant service times
We consider a discrete-time infinite-capacity queueing system with a general uncorrelated arrival process, constant-length service times of multiple slots, multiple servers and a first-come-first-served queueing discipline. Under the assumption that the queueing system can reach a steady state, we first establish a relationship between the steady-state probability distributions of the system content and the customer delay. Next, by means of this relationship, an explicit expression for the probability generating function of the customer delay is obtained from the known generating function of the system content, derived in previous work. In addition, several characteristics of the customer delay, namely the mean value, the variance and the tail distribution of the delay, are derived through some mathematical manipulations. The analysis is illustrated by means of some numerical examples.
Queueing Discrete time Multiple servers Constant service times Delay analysis
http://www.sciencedirect.com/science/article/B6VCT-4TT359Y-2/2/af85597d91800ae741c174ad39bdaf7d
Gao, Peixia
Wittevrongel, Sabine
Walraevens, Joris
Moeneclaey, Marc
Bruneel, Herwig
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:620-6292009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:620-629
article
Hybridizing exact methods and metaheuristics: A taxonomy
The interest about hybrid optimization methods has grown for the last few years. Indeed, more and more papers about cooperation between heuristics and exact techniques are published. In this paper, we propose to extend an existing taxonomy for hybrid methods involving heuristic approaches in order to consider cooperative schemes between exact methods and metaheuristics. First, we propose some natural approaches for the different schemes of cooperation encountered, and we analyse, for each model, some examples taken from the literature. Then we recall and complement the proposed grammar and provide an annotated bibliography.
Taxonomy Combinatorial optimisation Metaheuristics Exact methods
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-5/2/da4a040e6d29d78527bb46fcab2eeacd
Jourdan, L.
Basseur, M.
Talbi, E.-G.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:803-8102009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:803-810
article
Community facilitation of problem structuring and decision making processes: Experiences from the EU LEADER+ programme
This paper reports on the work carried out supporting a rural community in Denmark under the LEADER+ programme. This is a programme that supports development in particularly vulnerable rural regions of the European countries members of EU. It supports creative and innovative projects that can contribute to long-term and sustainable development in these regions. The main tasks have been the organisation and facilitation of conferences and workshops to structure the problematic situation of identifying and designing innovative projects for the development of the community and to support decision making processes related to the agreement on action plans. Learning to design, plan, manage and facilitate conferences and workshops have also being another central activity. The main purpose of these conferences and workshops was not only problem structuring and decision making in connection with community development but also the transfer of facilitation skills and appropriate methods to the community.
Community OR Facilitation Problem structuring Creative workshops
http://www.sciencedirect.com/science/article/B6VCT-4VYP94C-3/2/815d150ecd89e72186c1276c224169c1
Vidal, René Victor Valqui
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:236-2512009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:236-251
article
Multi-reservoir production optimization
When a large oil or gas field is produced, several reservoirs often share the same processing facility. This facility is typically capable of processing only a limited amount of commodities per unit of time. In order to satisfy these processing limitations, the production needs to be choked, i.e., scaled down by a suitable choke factor. A production strategy is defined as a vector valued function defined for all points of time representing the choke factors applied to reservoirs at any given time. In the present paper we consider the problem of optimizing such production strategies with respect to various types of objective functions. A general framework for handling this problem is developed. A crucial assumption in our approach is that the potential production rate from a reservoir can be expressed as a function of the remaining recoverable volume. The solution to the optimization problem depends on certain key properties, e.g., convexity or concavity, of the objective function and of the potential production rate functions. Using these properties several important special cases can be solved. An admissible production strategy is a strategy where the total processing capacity is fully utilized throughout a plateau phase. This phase lasts until the total potential production rate falls below the processing capacity, and after this all the reservoirs are produced without any choking. Under mild restrictions on the objective function the performance of an admissible strategy is uniquely characterized by the state of the reservoirs at the end of the plateau phase. Thus, finding an optimal admissible production strategy, is essentially equivalent to finding the optimal state at the end of the plateau phase. Given the optimal state a backtracking algorithm can then used to derive an optimal production strategy. We will illustrate this on a specific example.
OR in natural resources Convex Programming Linear Programming Global optimization Risk analysis
http://www.sciencedirect.com/science/article/B6VCT-4V2HKGR-1/2/f11ce800a2df3adadc9c78f5e4747f85
Huseby, Arne Bang
Haavardsson, Nils F.
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:630-6392009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:630-639
article
An adaptive heuristic algorithm for VLSI test vectors selection
The increasing complexity of today's system-on-a-chip designs is putting more pressure on the already stressed design verification process. The verification plan must cover several individual cores as well as the overall chip design. Conditions to be verified are identified by the system's architects, the designers, and the verification team. Testing for these conditions is a must for the design to tape out, especially for high priority conditions. A significant bottleneck in the verification process of such designs is that not enough time is usually given to the final coverage phase, which makes computing cycles very precious. Thus, intelligent selection of test vectors that achieve the best coverage using the minimum number of computing cycles is crucial for on time tape out. This paper presents a novel heuristic algorithm for test vectors selection. The algorithm attempts to achieve the best coverage level while minimizing the required number of computing cycles.
Heuristic algorithms Integer programming VLSI Verification SCP
http://www.sciencedirect.com/science/article/B6VCT-4S8K9FW-1/2/589567cd7acceea7b71232bcacc2ad15
Ibrahim, Walid
El-Sayed, Hesham
El-Chouemie, Amr
Amer, Hoda
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:822-8292009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:822-829
article
Channel coordination through a revenue sharing contract in a two-period newsboy problem
This paper studies channel coordination through revenue sharing contract between a single retailer and a single wholesaler in a two-period newsboy problem. Two models are discussed, a single-buying-opportunity model and a two-buying-opportunity model. We discuss how the revenue sharing ratio and the wholesale prices are to be determined in order to achieve channel coordination and a win-win outcome. We find that the wholesale prices are set to be lower than the retail prices and the optimal revenue sharing ratio is linearly increasing in the wholesale prices. The proposed revenue sharing contract has more flexibility than price protection, in that the optimal revenue sharing ratio can be settled reasonably through negotiation between the retailer and wholesaler.
Supply chain management Channel coordination Revenue sharing contract Two-period newsboy problem
http://www.sciencedirect.com/science/article/B6VCT-4TT9GH2-2/2/9bf5ba194530bfa001931888c979b5ee
Linh, Cao To
Hong, Yushin
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:760-7722009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:760-772
article
Studying the interdependence of contractual and operational flexibilities in the market of specialty chemicals
This paper focuses on the market of specialty chemicals and deals with the joint investigation and valuation of contractual and operational flexibilities from a manufacturers' point of view. In this market, customized services related to research, development and manufacturing of chemicals, intermediates and active pharmaceutical ingredients are offered to a small number of customers. Traditionally, customers are granted a large degree of freedom with respect to demand quantity and time exposing the manufacturer to high uncertainty and financial risk. Using a model-based approach we quantify the effect of this contractual flexibility and relate it to the manufacturing flexibility concerning capacity allocation. Through the valuation of these flexibilities we provide first insights for the manufacturer on which customer requests to accept, how to set up the associated contracts with the customers and how to allocate capacity for a given portfolio of products.
Supply chain management Production-marketing interface Flexibility Uncertainty
http://www.sciencedirect.com/science/article/B6VCT-4TTMNBR-2/2/89614373c2f597b0c871ff31d5e2013d
Reimann, Marc
Schiltknecht, Philippe
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:655-6652009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:655-665
article
Advertising strategies in a franchise system
The main question of this research is: Who should undertake promotional and brand-image advertising if the franchisor and franchisees act so as to maximize their respective profits? To address this question, we study a two-stage advertising game between a franchisor and two adjacent franchisees. In the first stage of the game, the franchisor chooses between three advertising models - centralizing or delegating the two types of advertising to the franchisees or delegating only promotional advertising. In the second stage, given the franchisor's choice of an advertising model, the two franchisees decide whether or not to cooperate. Our main findings are that (1) the franchisees should cooperate if the franchisor delegates either both brand-image and promotional advertising or promotional advertising, although cooperation between franchisees does not necessary improve the franchisor's profits. (2) The choice of an advertising arrangement critically depends on the margins as well as the costs of performing both promotional and brand-image advertising. We also discuss the conditions under which the three advertising models should be implemented.
Game theory Marketing Franchising Cooperative advertising Horizontal cooperation
http://www.sciencedirect.com/science/article/B6VCT-4TKPVC6-2/2/efdf416216795ffb3cacfca4c551c7f6
Sigué, Simon Pierre
Chintagunta, Pradeep
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:922-9352009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:922-935
article
Incorporating congestion in preventive healthcare facility network design
Preventive healthcare aims at reducing the likelihood and severity of potentially life-threatening illnesses by protection and early detection. The level of participation to preventive healthcare programs is a crucial factor in terms of their effectiveness and efficiency. This paper provides a methodology for designing a network of preventive healthcare facilities so as to maximize participation. The number of facilities to be established and the location of each facility are the main determinants of the configuration of a healthcare facility network. We use the total (travel, waiting and service) time required for receiving the preventive service as a proxy for accessibility of a healthcare facility, and assume that each client would seek the services of the facility with minimum expected total time. At each facility, which we model as an M/M/1 queue so as to capture the level of congestion, the expected number of participants from each population zone decreases with the expected total time. In order to ensure service quality, the facilities cannot be operated unless their level of activity exceeds a minimum workload requirement. The arising mathematical formulation is highly nonlinear, and hence we provide a heuristic solution framework for this problem. Four heuristics are compared in terms of accuracy and computational requirements. The most efficient heuristic is utilized in solving a real life problem that involves the breast cancer screening center network in Montreal. In the context of this case, we found out that centralizing the total system capacity at the locations preferred by clients is a more effective strategy than decentralization by the use of a larger number of smaller facilities. We also show that the proposed methodology can be used in making the investment trade-off between expanding the total system capacity and changing the behavior of potential clients toward preventive healthcare programs by advertisement and education.
Preventive healthcare Facility location Congestion Heuristic
http://www.sciencedirect.com/science/article/B6VCT-4TYJTYS-1/2/7a5637c1531f9fdccb6232fc41208afc
Zhang, Yue
Berman, Oded
Verter, Vedat
oai:RePEc:eee:ejores:v:198:y:2009:i:3:p:958-9742009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:3:p:958-974
article
Manufacturer-buyer coordination for newsvendor-type-products with two ordering opportunities and partial backorders
In a recent paper [Weng, Z.K., 2004. Coordinating order quantities between the manufacturer and the buyer: A generalized newsvendor model. European Journal of Operational Research 156, 148-161], a newsvendor-type coordination model was developed for a single-manufacturer single-buyer channel with two ordering opportunities. This paper further extends the model to the case where the excess demand after the first order is partially backlogged and both parties share the manufacturing setup cost of the second order (if happened). We show that the decentralized system would perform best if the manufacturer covers utterly the second production setup cost, which is opposite to that obtained in Weng (2004). Another extension in the present paper is that in the centralized system, the second order decision is made by the buyer based on the channel's benefit rather than based on the buyer's benefit as in Weng (2004). It is proved that the expected profit of the system in our paper is always larger than that in Weng (2004). In order to maximize the expected profit of the channel, two coordinated policies are proposed to achieve perfect coordination: a two-part-tariff policy for the special case that the buyer pays all the manufacturing setup cost, and a revised revenue-sharing contract for the case that two parties share the manufacturing setup cost.
Supply chain coordination Newsvendor model Two ordering opportunities Partial backlogging Revised revenue-sharing contract
http://www.sciencedirect.com/science/article/B6VCT-4TVTJKM-1/2/19e297006b7fc5f2e39057ae379f5eda
Zhou, Yong-Wu
Wang, Sheng-Dong
oai:RePEc:eee:ejores:v:199:y:2009:i:3:p:867-8722009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:3:p:867-872
article
Structures in decision making: On the subjective geometry of hierarchies and networks
In the field of decision making, creating a structure is the first step in organizing, representing and solving a problem. A structure is a model, an abstraction of a problem. It helps us visualize and understand the relevant elements within it that we know from the real world and then use our understanding to solve the problem represented in the structure with greater confidence. In general, there are two kinds of structures used to represent problems: hierarchies and networks. Both rely to a varying degree on the interactions. Some examples are given followed by a discussion about how to structure the problem. At a minimum, a structure must satisfy two requirements: that it be logical in identifying and grouping similar things together, and that it relates them accurately according to the flow of influence among them. It must be complete with nothing left out that has an important influence. The structure is then tested as to whether it helps solve the problem to one's satisfaction.
Hierarchy Network Structure Decision making Problem solving Subjective geometry
http://www.sciencedirect.com/science/article/B6VCT-4VYXMKW-6/2/d42e3f2815251d252e39020e35ca3a3c
Saaty, Thomas L.
Shih, Hsu-Shih
oai:RePEc:eee:ejores:v:199:y:2009:i:1:p:311-3132009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:199:y:2009:i:1:p:311-313
article
Erik D. Demaine and Joseph O'Rouke, Review of Geometric Folding Algorithms: Linkages, Origami, Polyhedra , Cambridge University Press (2007).
http://www.sciencedirect.com/science/article/B6VCT-4SRW13D-1/2/2d94acc8cc24ab223e513f0621c9cc73
Paquete, Luís
oai:RePEc:eee:ejores:v:198:y:2009:i:2:p:637-6462009-07-30RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:2:p:637-646
article
An exact method for computing the nadir values in multiple objective linear programming
In this paper we propose a new method to determine the exact nadir (minimum) criterion values over the efficient set in multiple objective linear programming (MOLP). The basic idea of the method is to determine, for each criterion, the region of the weight space associated with the efficient solutions that have a value in that criterion below the minimum already known (by default, the minimum in the payoff table). If this region is empty, the nadir value has been found. Otherwise, a new efficient solution is computed using a weight vector picked from the delimited region and a new iteration is performed. The method is able to find the nadir values in MOLP problems with any number of objective functions, although the computational effort increases significantly with the number of objectives. Computational experiments are described and discussed, comparing two slightly different versions of the method.
Multiple criteria analysis Multiple objective programming Nadir point
http://www.sciencedirect.com/science/article/B6VCT-4TPF4FF-4/2/e761b123cb52901881786663a32e8cb6
Alves, Maria João
Costa, João Paulo
oai:RePEc:eee:ejores:v:214:y:2011:i:1:p:85-902011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:1:p:85-90
article
An effective Markov based approach for calculating the Limit Matrix in the analytic network process
Analytic network process is a multiple criteria decision analysis (MCDA) method that aids decision makers to choose among a number of possible alternatives or prioritize the criteria for making a decision in terms of importance. It handles both qualitative and quantitative criteria, that are compared in pairs, in order to forge a best compromise answer according to the different criteria and influences involved. The method has been widely applied and the literature review reveals a rising trend of ANP-related articles. The 'power' matrix method, a procedure necessary for the stability of the decision system, is one of the critical calculations in the mathematical part of the method. The present study proposes an alternative mathematical approach that is based on Markov chain processes and the well-known Gauss-Jordan elimination. The new approach obtains practically the same results as the power matrix method, requires slightly less time and number of calculations and handles effectively cyclic supermatrices, optimizing thus the whole procedure.
Markov processes Multiple criteria decision analysis Analytic network process 'Power' matrix method
http://www.sciencedirect.com/science/article/pii/S0377221711002803
Kirytopoulos, Konstantinos
Voulgaridou, Dimitra
Platis, Agapios
Leopoulos, Vrassidas
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:89-962011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:89-96
article
Discrete-time, economic lot scheduling problem on multiple, non-identical production lines
This paper deals with a general discrete time dynamic demand model to solve real time resource allocation and lot-sizing problems in a multimachine environment. In particular, the problem of apportioning item production to distinct manufacturing lines with different costs (production, setup and inventory) and capabilities is considered. Three models with different cost definitions are introduced, and a set of algorithms able to handle all the problems are developed. The computational results show that the best of the developed approaches is able to handle problems with up to 10000 binary variables outperforming general-purpose solvers and other randomized approaches. The gap between lower and upper bound procedures is within 1.0% after about 500 seconds of CPU time on a 2.66Â Ghz Intel Core2 PC.
Lot-sizing Scheduling Beam search Matheuristicm Resource allocation
http://www.sciencedirect.com/science/article/pii/S0377221711005017
Bollapragada, Ramesh
Croce, Federico Della
Ghirardi, Marco
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:546-5582011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:546-558
article
Solving a continuous local access network design problem with a stabilized central column generation approach
In this paper, we focus on a variant of the multi-source Weber problem. In the multi-source Weber problem, the location of a fixed number of concentrators, and the allocation of terminals to them, must be chosen to minimize the total cost of links between terminals and concentrators. In our variant, we have a third hierarchical level, two categories of link costs, and the number of concentrators is unknown. To solve this difficult problem, we propose several heuristics, and use a new stabilized column generation approach, based on a central cutting plane method, to provide lower bounds.
Location Combinatorial optimization Column generation Central cutting plane Multi-source Weber problem
http://www.sciencedirect.com/science/article/pii/S0377221711004462
Trampont, M.
Destré, C.
Faye, A.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:188-1932011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:188-193
article
Do investors like to diversify? A study of Markowitz preferences
We study rankings of completely and partially diversified portfolios and also of specialized assets when investors follow so-called Markowitz preferences. It turns out that diversification strategies for Markowitz investors are more complex than in the case of risk-averse and risk-inclined investors, whose investment strategies have been extensively investigated in the literature. In particular, we observe that for Markowitz investors, preferences toward risk vary depending on their sensitivities toward gains and losses. For example, it turns out that, unlike in the case of risk-averse and risk-inclined investors, Markowitz investors might prefer investing their entire wealth in just one asset. This finding helps us to better understand some financial anomalies and puzzles, such as the well known diversification puzzle, which notes that some investors tend to concentrate on investing in only a few assets instead of choosing the seemingly more attractive complete diversification.
Portfolio selection Diversified portfolio Markowitz preferences Utility theory Risk aversion
http://www.sciencedirect.com/science/article/pii/S0377221711004590
Egozcue, Martín
García, Luis Fuentes
Wong, Wing-Keung
Zitikis, Ricardas
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:218-2262011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:218-226
article
A sequential perspective on searching for static targets
We present a sequential approach to detect static targets with imperfect sensors, which range from tower-mounted cameras to satellites. The scenario is operationally relevant to many military, homeland security, search and rescue, environmental engineering, counter-narcotics, and law enforcement applications. The idea is to stop the search as soon as there is enough probabilistic evidence about the targets' locations, given an operator-prescribed error tolerance, knowledge of the sensors' parameters, and a sequence of detection signals from the sensors. By stopping the search as soon as possible, we promote efficiency by freeing up sensors and operators to perform other tasks. The model we develop has the added benefits of decreasing operator workload and providing negative information as a search progresses.
Applied probability OR in military Sequential analysis
http://www.sciencedirect.com/science/article/pii/S0377221711004930
Wilson, Kurt E.
Szechtman, Roberto
Atkinson, Michael P.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:559-5672011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:559-567
article
Transportation pricing of a truckload carrier
Freight transportation is a major component of logistical operations. Due to the increase in global trade, fierce competition among shippers and raising concerns about energy, companies are putting more emphasis on effective management and usage of transportation services. This paper studies the transportation pricing problem of a truckload carrier in a setting that consists of a retailer, a truckload carrier and a less than truckload carrier. In this setting, the truckload carrier makes his/her pricing decision based on previous knowledge on the less than truckload carrier's price schedule and the retailer's ordering behavior. The retailer then makes a determination of his/her order quantity through an integrated model that explicitly considers the transportation alternatives, and the related costs (i.e., bimodal transportation costs) and capacities. In the paper, the retailer's replenishment problem and the truckload carrier's pricing problem are modeled and solved based on a detailed analysis. Numerical evidence shows that the truckload carrier may increase his/her gainings significantly through better pricing and there is further opportunity of savings if the truckload carrier and the retailer coordinate their decisions.
Transportation pricing Supply chain management Truckload carrier Less than truckload carrier Integrated inventory/transportation
http://www.sciencedirect.com/science/article/pii/S0377221711004103
Toptal, Aysegül
Bingöl, Safa Onur
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:780-7952011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:780-795
article
Sequential clinical scheduling with service criteria
This study investigates sequential appointment scheduling with service criteria. It uses a constraint-based approach with service criteria bounded in a constraint set in contrast to the more typical weighted linear objective function. Properties are derived and a sequential scheduling algorithm is developed. Fairness properties of generated schedules are considered in detail, where fairness is the uniformity of performance across patients. New unfairness measures are proposed and used to capture the inequity among patients assigned to different slots. Other criteria such as expectation and variance of patient waiting time, queue length, and overtime are also considered. The fairness/revenue tradeoff is investigated as is the flexibility of the constraint-based approach in handling unavailable time periods.
Multiple criteria clinical scheduling Moment-based constraints Overbooking Pareto optimal set
http://www.sciencedirect.com/science/article/pii/S0377221711004486
Turkcan, Ayten
Zeng, Bo
Muthuraman, Kumar
Lawley, Mark
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:39-442011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:39-44
article
Two-agent scheduling to minimize the total cost
Two agents, each having his own set of jobs, compete to perform their own jobs on a common processing resource. Each job of the agents has a weight that specifies its importance. The cost of the first agent is the maximum weighted completion time of his jobs while the cost of the second agent is the total weighted completion time of his jobs. We consider the scheduling problem of determining the sequence of the jobs such that the total cost of the two agents is minimized. We provide a 2-approximation algorithm for the problem, show that the case where the number of jobs of the first agent is fixed is NP-hard, and devise a polynomial time approximation scheme for this case.
Scheduling Multi-agent Approximation algorithm Polynomial time approximation scheme
http://www.sciencedirect.com/science/article/pii/S0377221711004899
Nong, Q.Q.
Cheng, T.C.E.
Ng, C.T.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:115-1252011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:115-125
article
Holding costs under push or pull conditions - The impact of the Anchor Point
Holding costs are traditionally determined from the investment in physical stock during a cycle. An alternative approach instead derives holding costs from Net Present Value (NPV) functions. It is known that applying both frameworks to the same system can lead to different holding cost valuations, but little explanation has been offered. By introducing the Anchor Point in a model, this paper shows, for four different systems, that traditional holding cost models (implicitly) assume pull conditions, while current NPV approaches model push conditions. This explains in part the differences between the methods. It is shown that the Anchor Point concept allows the construction of NPV models under pull conditions, giving results in better correspondence with traditional models. The traditional framework is restricted to pull conditions and important considerations could be easily overlooked, leading to wrong valuations of holding costs. NPV seems superior as such considerations are automatically incorporated. The application to multi-echelon inventory systems provides interesting insights on the roles of echelon stocks and lead-times, and offers potential for future research.
Inventory Production Net Present Value Average profit models Multi-echelon inventory theory
http://www.sciencedirect.com/science/article/pii/S037722171100511X
Beullens, Patrick
Janssens, Gerrit K.
oai:RePEc:eee:ejores:v:209:y:2011:i:1:p:73-822011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:209:y:2011:i:1:p:73-82
article
Strategic disclosure of random variables
We consider a game Gn played by two players. There are n independent random variables Z1, ... , Zn, each of which is uniformly distributed on [0,1]. Both players know n, the independence and the distribution of these random variables, but only player 1 knows the vector of realizations z := (z1, ... , zn) of them. Player 1 begins by choosing an order zk1,...,zkn of the realizations. Player 2, who does not know the realizations, faces a stopping problem. At period 1, player 2 learns zk1. If player 2 accepts, then player 1 pays zk1 euros to player 2 and play ends. Otherwise, if player 2 rejects, play continues similarly at period 2 with player 1 offering zk2 euros to player 2. Play continues until player 2 accepts an offer. If player 2 has rejected n - 1 times, player 2 has to accept the last offer at period n. This model extends Moser's (1956) problem, which assumes a non-strategic player 1. We examine different types of strategies for the players and determine their guarantee-levels. Although we do not find the exact max-min and min-max values of the game Gn in general, we provide an interval In = [an, bn] containing these such that the length of In is at most 0.07 and converges to 0 as n tends to infinity. We also point out strategies, with a relatively simple structure, which guarantee that player 1 has to pay at most bn and player 2 receives at least an. In addition, we completely solve the special case G2 where there are only two random variables. We mention a number of intriguing open questions and conjectures, which may initiate further research on this subject.
Secretary problem Moser's problem Incomplete information Lack of information on one side Optimal strategies
http://www.sciencedirect.com/science/article/B6VCT-50XCY23-1/2/82a724fd6ba491a358b99960350bf087
Flesch, János
Perea, Andrés
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:512-5252011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:512-525
article
A heuristic for the circle packing problem with a variety of containers
In this paper we present a heuristic algorithm based on the formulation space search method to solve the circle packing problem. The circle packing problem is the problem of finding the maximum radius of a specified number of identical circles that can be fitted, without overlaps, into a two-dimensional container of fixed size. In this paper we consider a variety of containers: the unit circle, unit square, rectangle, isosceles right-angled triangle and semicircle. The problem is formulated as a nonlinear optimization problem involving both Cartesian and polar coordinate systems. Formulation space search consists of switching between different formulations of the same problem, each formulation potentially having different properties in terms of nonlinear optimization. As a component of our heuristic we solve a nonlinear optimization problem using the solver SNOPT. Our heuristic improves on previous results based on formulation space search presented in the literature. For a number of the containers we improve on the best result previously known. Our heuristic is also a computationally effective approach (when balancing quality of result obtained against computation time required) when compared with other work presented in the literature.
Circle packing Formulation space search Metaheuristic
http://www.sciencedirect.com/science/article/pii/S0377221711003687
López, C.O.
Beasley, J.E.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:126-1352011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:126-135
article
An artificial bee colony algorithm for the capacitated vehicle routing problem
This paper introduces an artificial bee colony heuristic for solving the capacitated vehicle routing problem. The artificial bee colony heuristic is a swarm-based heuristic, which mimics the foraging behavior of a honey bee swarm. An enhanced version of the artificial bee colony heuristic is also proposed to improve the solution quality of the original version. The performance of the enhanced heuristic is evaluated on two sets of standard benchmark instances, and compared with the original artificial bee colony heuristic. The computational results show that the enhanced heuristic outperforms the original one, and can produce good solutions when compared with the existing heuristics. These results seem to indicate that the enhanced heuristic is an alternative to solve the capacitated vehicle routing problem.
Routing Artificial bee colony Metaheuristic
http://www.sciencedirect.com/science/article/pii/S0377221711005121
Szeto, W.Y.
Wu, Yongzhong
Ho, Sin C.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:80-882011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:80-88
article
An optimal solution technique to the single-vendor multi-buyer integrated inventory supply chain by incorporating some realistic factors
This paper develops two generalized integrated inventory models to deliver a single product from a vendor to multiple buyers. To minimize the total cost of set up, ordering, inventory holding and transportation, the production flow is synchronized by transferring the lot with equal and/or unequal (either all are equal or all are unequal or a combination of equal and unequal) sized batches (sub-lots), each of which incurs a transportation cost. For easy implementation of the models, we relax some unrealistic assumptions in the existing models such as unlimited capacities of the transport equipment and buyers' storage, insignificant set up and transportation times, unlimited lead time and batch sizes. A common optimal solution technique to the models is derived and their performances are analyzed. Potential significances of the solution method are highlighted with solutions of some numerical problems. The importance of the relaxed factors and limitation of the models are discussed.
Synchronization Integrated inventory Constraint Optimal solution
http://www.sciencedirect.com/science/article/pii/S0377221711004619
Hoque, M.A.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:627-6432011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:627-643
article
QoS commitment between vertically integrated autonomous systems
Vertically integrated autonomous systems bargain to provide quality of service guarantees and revenue sharing. Depending on the perceived quality of service and access price, consumers determine whether they subscribe to the access provider's service. Four types of contracts are compared: (i) best effort, (ii) bilateral bargaining, (iii) cascade negotiations and (iv) grand coalition cooperation; the impact of the consumers' QoS sensitivity parameter and power relation are tested for each contract. Assuming that the consumers' quality of service sensitivity parameter is unknown and might evolve dynamically due to error judgement, word-of-mouth effect or competition pressure, a learning algorithm is detailed and implemented by each integrated autonomous systems under asymmetrical information. Its convergence and the influence of bias introduction by the most informed autonomous system is analyzed.
Bilateral bargaining Supply chain Shapley value Learning
http://www.sciencedirect.com/science/article/pii/S0377221711003870
Le Cadre, Hélène
Barth, Dominique
Pouyllau, Hélia
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:814-8172011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:814-817
article
Cost evaluation in M/G/1 queue with T-policy revisited, technical note
This note clarifies the concept of regeneration cycle used in evaluating the average operating cost of the M/G/1 queue with T-policy studied in 70s. Two ways of defining the regeneration cycle are compared and advantages and disadvantages of each way are pointed out. In addition, we establish the convexity of the cost function based on the service cycle.
M/G/1 queue T-policy N-policy Busy cycle Service cycle Convexity
http://www.sciencedirect.com/science/article/pii/S0377221711004917
Zhang, Zhe George
Tadj, Lotfi
Bounkhel, Messaoud
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:805-8132011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:805-813
article
Enhancing credit default swap valuation with meshfree methods
In this paper, we apply the meshfree radial basis function (RBF) interpolation to numerically approximate zero-coupon bond prices and survival probabilities in order to price credit default swap (CDS) contracts. We assume that the interest rate follows a Cox-Ingersoll-Ross process while the default intensity is described by the Exponential-Vasicek model. Several numerical experiments are conducted to evaluate the approximations by the RBF interpolation for one- and two-factor models. The results are compared with those estimated by the finite difference method (FDM). We find that the RBF interpolation achieves more accurate and computationally efficient results than the FDM. Our results also suggest that the correlation between factors does not have a significant impact on CDS spreads.
Radial basis function interpolation Finite difference methods Default intensity
http://www.sciencedirect.com/science/article/pii/S0377221711004942
Guarin, Alexander
Liu, Xiaoquan
Ng, Wing Lon
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:70-792011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:70-79
article
A real-time decision rule for an inventory system with committed service time and emergency orders
In this paper, we study the inventory system of an online retailer with compound Poisson demand. The retailer normally replenishes its inventory according to a continuous review (nQ,Â R) policy with a constant lead time. Usually demands that cannot be satisfied immediately are backordered. We also assume that the customers will accept a reasonable waiting time after they have placed their orders because of the purchasing convenience of the online system. This means that a sufficiently short waiting time incurs no shortage costs. We call this allowed waiting time "committed service time". After this committed service time, if the retailer is still in shortage, the customer demand must either be satisfied with an emergency supply that takes no time (which is financially equivalent to a lost sale) or continue to be backordered with a time-dependent backorder cost. The committed service time gives an online retailer a buffer period to handle excess demands. Based on real-time information concerning the outstanding orders of an online retailer and the waiting times of its customers, we provide a decision rule for emergency orders that minimizes the expected costs under the assumption that no further emergency orders will occur. This decision rule is then used repeatedly as a heuristic. Numerical examples are presented to illustrate the model, together with a discussion of the conditions under which the real-time decision rule provides considerable cost savings compared to traditional systems.
Inventory Partial backordering Emergency orders Committed service time
http://www.sciencedirect.com/science/article/pii/S0377221711004541
Huang, Shuo
Axsäter, Sven
Dou, Yifan
Chen, Jian
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:656-6642011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:656-664
article
Statistical properties and economic implications of jump-diffusion processes with shot-noise effects
The shot-noise jump-diffusion (SNJD) model aims to reflect how economic variables respond to the arrival of sudden information. This paper analyzes the SNJD model, providing its statistical distribution and closed-form expressions for the characteristic function and moments. We also analyze the dynamics of the model, concluding that the degree of serial autocorrelation is related to the occurrence and magnitude of abnormal information. In addition, we provide some useful approximations in a particular case that considers exponential-type decay. Empirically, we propose a GMM approach to estimate the parameters of the model and present an empirical application for the stocks included in the Dow Jones Averaged Index. Our findings seem to confirm the presence of shot-noise effects in 73% of the stocks and a strong relationship between the shot-noise process and the autocorrelation pattern embedded in data.
Finance Shot-noise Characteristic function Generalized method of moments
http://www.sciencedirect.com/science/article/pii/S0377221711004176
Moreno, Manuel
Serrano, Pedro
Stute, Winfried
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:536-5452011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:536-545
article
Solving the vehicle routing problem with time windows and multiple routes exactly using a pseudo-polynomial model
In this paper, we address a variant of the vehicle routing problem called the vehicle routing problem with time windows and multiple routes. It considers that a given vehicle can be assigned to more than one route per planning period. We propose a new exact algorithm for this problem. Our algorithm is iterative and it relies on a pseudo-polynomial network flow model whose nodes represent time instants, and whose arcs represent feasible vehicle routes. This algorithm was tested on a set of benchmark instances from the literature. The computational results show that our method is able to solve more instances than the only other exact method described so far in the literature, and it clearly outperforms this method in terms of computing time.
Integer programming Combinatorial optimization Routing Network flows
http://www.sciencedirect.com/science/article/pii/S037722171100381X
Macedo, Rita
Alves, Cláudio
Valério de Carvalho, J.M.
Clautiaux, François
Hanafi, Saïd
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:194-2032011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:194-203
article
A knowledge-based multi-role decision support system for ore blending cost optimization of blast furnaces
Literature illustrates the difficulties in obtaining the lowest-cost optimal solution to an ore blending problem for blast furnaces by using the traditional trial-and-error method in iron and steel enterprises. To solve this problem, we developed a cost optimization model which we have implemented in a multi-role-based decision support system (DSS). On the basis of analyzing the business flow and working process of ore blending, we propose an architecture of DSS which is built based on multi-roles. This DSS construction pre-processes the data for materials and elements, builds a general database, abstracts the related optimal operations research models and introduces the reasoning mechanism of an expert system. A non-linear model of ore blending for blast furnaces and its solutions are provided. A database, a model base and a knowledge base are integrated into the expert system-based multi-role DSS to meet the different demands of data, information and decision-making knowledge for the various roles of users. A comparison of the results for the DSS and the trial-and-error method is provided. The system has produced excellent economic benefits since it was implemented at the Xiangtan Iron & Steel Group Co. Ltd., China.
Decision support systems Cost optimization Expert system Ore blending
http://www.sciencedirect.com/science/article/pii/S0377221711004620
Zhang, Ruijun
Lu, Jie
Zhang, Guangquan
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:57-692011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:57-69
article
A two-stage intelligent search algorithm for the two-dimensional strip packing problem
This paper presents a two-stage intelligent search algorithm for a two-dimensional strip packing problem without guillotine constraint. In the first stage, a heuristic algorithm is proposed, which is based on a simple scoring rule that selects one rectangle from all rectangles to be packed, for a given space. In the second stage, a local search and a simulated annealing algorithm are combined to improve solutions of the problem. In particular, a multi-start strategy is designed to enhance the search capability of the simulated annealing algorithm. Extensive computational experiments on a wide range of benchmark problems from zero-waste to non-zero-waste instances are implemented. Computational results obtained in less than 60Â seconds of computation time show that the proposed algorithm outperforms the supposedly excellent algorithms reported recently, on average. It performs particularly better for large instances.
Packing problem Heuristic search Simulated annealing
http://www.sciencedirect.com/science/article/pii/S037722171100508X
Leung, Stephen C.H.
Zhang, Defu
Sim, Kwang Mong
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:473-4842011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:473-484
article
Full Nesterov-Todd step infeasible interior-point method for symmetric optimization
Euclidean Jordan algebras were proved more than a decade ago to be an indispensable tool in the unified study of interior-point methods. By using it, we generalize the full-Newton step infeasible interior-point method for linear optimization of Roos [Roos, C., 2006. A full-Newton step O(n) infeasible interior-point algorithm for linear optimization. SIAM Journal on Optimization. 16 (4), 1110-1136 (electronic)] to symmetric optimization. This unifies the analysis for linear, second-order cone and semidefinite optimizations.
Interior point methods Conic programming Nesterov-Todd step
http://www.sciencedirect.com/science/article/pii/S0377221711001779
Gu, G.
Zangiabadi, M.
Roos, C.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:796-8042011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:796-804
article
Stable solutions for optimal reinsurance problems involving risk measures
The optimal reinsurance problem is a classic topic in actuarial mathematics. Recent approaches consider a coherent or expectation bounded risk measure and minimize the global risk of the ceding company under adequate constraints. However, there is no consensus about the risk measure that the insurer must use, since every risk measure presents advantages and shortcomings when compared with others. This paper deals with a discrete probability space and analyzes the stability of the optimal reinsurance with respect to the risk measure that the insurer uses. We will demonstrate that there is a "stable optimal retention" that will show no sensitivity, insofar as it will solve the optimal reinsurance problem for many risk measures, thus providing a very robust reinsurance plan. This stable optimal retention is a stop-loss contract, and it is easy to compute in practice. A fast linear time algorithm will be given and a numerical example presented.
Optimal reinsurance Risk measure Sensitivity Stable optimal retention Stop-loss reinsurance
http://www.sciencedirect.com/science/article/pii/S0377221711004607
Balbás, Alejandro
Balbás, Beatriz
Heras, Antonio
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:25-382011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:25-38
article
A polynomial arc-search interior-point algorithm for convex quadratic programming
Arc-search is developed for linear programming in [24] and [25]. The algorithms search for optimizers along an ellipse that is an approximation of the central path. In this paper, the arc-search method is applied to primal-dual path-following interior-point method for convex quadratic programming. A simple algorithm with iteration complexity is devised. Several improvements on the simple algorithm, which improve computational efficiency, increase step length, and further reduce duality gap in every iteration, are then proposed and implemented. It is intuitively clear that the iteration with these improvements will reduce the duality gap more than the iteration of the simple algorithm without the improvements, though it is hard to show how much these improvements reduce the complexity bound. The proposed algorithm is implemented in MATLAB and tested on quadratic programming problems originating from [13]. The result is compared to the one obtained by LOQO in [22]. The proposed algorithm uses fewer iterations in all these problems and the number of total iterations is 27% fewer than the one obtained by LOQO. This preliminary result shows that the proposed algorithm is promising.
Arc-search Convex quadratic programming Interior-point method Polynomial algorithm
http://www.sciencedirect.com/science/article/pii/S0377221711005492
Yang, Yaguang
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:674-6822011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:674-682
article
The impact of transportation delays on repairshop capacity pooling and spare part inventories
In this paper, to serve different fleets of machines at different locations, we study whether repair shop pooling is more cost effective than having dedicated on-site repair shops for each fleet. When modeling the former alternative, we take transportation delays and related costs into account and represent it as a closed queueing network. This allows us to include on-site spare-part inventories that operate according to a continuous-review base-stock policy. We obtain the steady-state distribution of components at each location and the cost of the system with a pooled repair shop by applying the Mean-Value Analysis technique. Our numerical findings indicate that when transportation costs are reasonable, repair shop pooling is a better alternative.
Spare parts Multiple finite-population queueing systems Transportation delays Mean-Value Analysis
http://www.sciencedirect.com/science/article/pii/S0377221711004474
Sahba, Pedram
BalcIog[small tilde]lu, BarIs
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:244-2562011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:244-256
article
Centralized and decentralized management of groundwater with multiple users
In this work, we investigate two groundwater inventory management schemes with multiple users in a dynamic game-theoretic structure: (i) under the centralized management scheme, users are allowed to pump water from a common aquifer with the supervision of a social planner, and (ii) under the decentralized management scheme, each user is allowed to pump water from a common aquifer making usage decisions individually in a non-cooperative fashion. This work is motivated by the work of Saak and Peterson [14], which considers a model with two identical users sharing a common aquifer over a two-period planning horizon. In our work, the model and results of Saak and Peterson [14] are generalized in several directions. We first build on and extend their work to the case of n non-identical users distributed over a common aquifer region. Furthermore, we consider two different geometric configurations overlying the aquifer, namely, the strip and the ring configurations. In each configuration, general analytical results of the optimal groundwater usage are obtained and numerical examples are discussed for both centralized and decentralized problems.
OR in natural resources Game theory Water resources management Darcy's Law
http://www.sciencedirect.com/science/article/pii/S0377221711004966
Saleh, Yahya
Gürler, Ülkü
Berk, Emre
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:768-7792011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:768-779
article
An integrated fuzzy simulation-fuzzy data envelopment analysis algorithm for job-shop layout optimization: The case of injection process with ambiguous data
This paper puts forward an integrated fuzzy simulation-fuzzy data envelopment analysis (FSFDEA) algorithm to cope with a special case of single-row facility layout problem (SRFLP). Discrete-event-simulation, a powerful tool for analyzing complex and stochastic systems, is employed for modeling different layout formations. Afterwards, a range-adjusted measure (RAM) is used as a data envelopment analysis (DEA) model for ranking the simulation results and finding the optimal layout design. Due to ambiguousness associated with the processing times, fuzzy sets theory is incorporated into the simulation model. Since the results of simulation are in the form of possibility distributions, the DEA model is treated on a fuzzy basis; therefore, a recent possibilistic programming approach is used to convert the fuzzy DEA model to an equivalent crisp one. The proposed FSFDEA algorithm is capable of modeling and optimizing small-sized SRFLP's in stochastic, uncertain, and non-linear environments. The solution quality is inspected through a real case study in a refrigerator manufacturing company.
Single-row facility layout problem Discrete-event-simulation Data envelopment analysis Fuzzy sets Possibilistic programming
http://www.sciencedirect.com/science/article/pii/S0377221711004401
Azadeh, A.
Moghaddam, M.
Asadzadeh, S.M.
Negahban, A.
oai:RePEc:eee:ejores:v:212:y:2011:i:2:p:374-3852011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:212:y:2011:i:2:p:374-385
article
Evaluating pharmaceutical R&D under technical and economic uncertainty
This study sets up a compound option approach for evaluating pharmaceutical R&D investment projects in the presence of technical and economic uncertainties. Technical uncertainty is modeled as a Poisson jump that allows for failure and thus abandonment of the drug development. Economic uncertainty is modeled as a standard diffusion process which incorporates both up-and downward shocks. Practical application of this method is emphasized through a case analysis. We show that both uncertainties have a positive impact on the R&D option value. Moreover, from the sensitivity analysis, we find that the sensitivity of the option with respect to economic uncertainty and market introduction cost decreases when technical uncertainty increases.
Compound option Jump-diffusion process R&D Pharmaceutical industry
http://www.sciencedirect.com/science/article/B6VCT-523V3CN-1/2/8169aa81d41aff5bf0120235669d79dc
Pennings, Enrico
Sereno, Luigi
oai:RePEc:eee:ejores:v:213:y:2011:i:2:p:442-4542011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:213:y:2011:i:2:p:442-454
article
Climate change and optimal energy technology R&D policy
Public policy response to global climate change presents a classic problem of decision making under uncertainty. Theoretical work has shown that explicitly accounting for uncertainty and learning in climate change can have a large impact on optimal policy, especially technology policy. However, theory also shows that the specific impacts of uncertainty are ambiguous. In this paper, we provide a framework that combines economics and decision analysis to implement probabilistic data on energy technology research and development (R&D) policy in response to global climate change. We find that, given a budget constraint, the composition of the optimal R&D portfolio is highly diversified and robust to risk in climate damages. The overall optimal investment into technical change, however, does depend (in a non-monotonic way) on the risk in climate damages. Finally, we show that in order to properly value R&D, abatement must be included as a recourse decision.
R&D portfolio Energy technology Climate change Stochastic programming Public policy
http://www.sciencedirect.com/science/article/pii/S0377221711003080
Baker, Erin
Solak, Senay
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:588-5942011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:588-594
article
Freight transportation in railway networks with automated terminals: A mathematical model and MIP heuristic approaches
In this paper we propose a planning procedure for serving freight transportation requests in a railway network with fast transfer equipment at terminals. We consider a transportation system where different customers make their requests (orders) for moving boxes, i.e., either containers or swap bodies, between different origins and destinations, with specific requirements on delivery times. The decisions to be taken concern the route (and the corresponding sequence of trains) that each box follows in the network and the assignment of boxes to train wagons, taking into account that boxes can change more than one train and that train timetables are fixed. The planning procedure includes a pre-analysis step to determine all the possible sequences of trains for serving each order, followed by the solution of a 0-1 linear programming problem to find the optimal assignment of each box to a train sequence and to a specific wagon for each train in the sequence. This latter is a generalized assignment problem which is NP-hard. Hence, in order to find good solutions in acceptable computation times, two MIP heuristic approaches are proposed and tested through an experimental analysis considering realistic problem instances.
Freight transportation Optimal planning Mathematical programming MIP heuristics
http://www.sciencedirect.com/science/article/pii/S0377221711004383
Anghinolfi, D.
Paolucci, M.
Sacone, S.
Siri, S.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:501-5112011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:501-511
article
The multiple container loading cost minimization problem
In the shipping and transportation industry, there are several types of standard containers with different dimensions and different associated costs. In this paper, we examine the multiple container loading cost minimization problem (MCLCMP), where the objective is to load products of various types into containers of various sizes so as to minimize the total cost. We transform the MCLCMP into an extended set cover problem that is formulated using linear integer programming and solve it with a heuristic to generate columns. Experiments on standard bin-packing instances show our approach is superior to prior approaches. Additionally, since the optimal solutions for existing test data is unknown, we propose a technique to generate test data with known optimal solutions for MCLCMP.
Packing Heuristics Container loading Integer programming Design of experiments
http://www.sciencedirect.com/science/article/pii/S0377221711003614
Che, Chan Hou
Huang, Weili
Lim, Andrew
Zhu, Wenbin
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:1-132011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:1-13
article
Lost-sales inventory theory: A review
In classic inventory models it is common to assume that excess demand is backordered. However, studies analyzing customer behavior in practice show that most unfulfilled demand is lost or an alternative item/location is looked for in many retail environments. Inventory systems that include this lost-sales characteristic appear to be more difficult to analyze and to solve. Furthermore, lost-sales inventory systems require different replenishment policies to minimize costs compared to backorder systems. In this paper, we classify the models in the literature based on the characteristics of the inventory system and review the proposed replenishment policies. For each classification and type of replenishment policy we discuss the available models and their performance. Furthermore, directions for future research are proposed.
Inventory Lost sales Replenishment policies Classification of literature
http://www.sciencedirect.com/science/article/pii/S0377221711001354
Bijvank, Marco
Vis, Iris F.A.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:749-7582011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:749-758
article
A mixed integer linear programming model for optimal sovereign debt issuance
Governments borrow funds to finance the excess of cash payments or interest payments over receipts, usually by issuing fixed income debt and index-linked debt. The goal of this work is to propose a stochastic optimization-based approach to determine the composition of the portfolio issued over a series of government auctions for the fixed income debt, to minimize the cost of servicing debt while controlling risk and maintaining market liquidity. We show that this debt issuance problem can be modeled as a mixed integer linear programming problem with a receding horizon. The stochastic model for the interest rates is calibrated using a Kalman filter and the future interest rates are represented using a recombining trinomial lattice for the purpose of scenario-based optimization. The use of a latent factor interest rate model and a recombining lattice provides us with a realistic, yet very tractable scenario generator and allows us to do a multi-stage stochastic optimization involving integer variables on an ordinary desktop in a matter of seconds. This, in turn, facilitates frequent re-calibration of the interest rate model and re-optimization of the issuance throughout the budgetary year allows us to respond to the changes in the interest rate environment. We successfully demonstrate the utility of our approach by out-of-sample back-testing on the UK debt issuance data.
Multistage stochastic programming Public debt management OR in government Finance
http://www.sciencedirect.com/science/article/pii/S037722171100378X
Date, P.
Canepa, A.
Abdel-Jawad, M.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:227-2432011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:227-243
article
SAPI: Statistical Analysis of Propagation of Incidents. A new approach for rescheduling trains after disruptions
In this paper, we present a new approach to solve the railway rescheduling problem. This problem deals with the reparation of a disturbed railway timetable after incidents in such a way to minimize the difference between the original plan and the new provisional plan. We use a mixed integer linear programming (MIP) formulation that models this problem correctly. However, the large number of variables and constraints denies the possibility to solve this problem efficiently using a standard MIP solver. A new approach called SAPI (Statistical Analysis of Propagation of Incidents) has been developed to tackle the problem. The key point of SAPI is to estimate the probability that an event, one step of the itinerary of a train, is affected by a set of incidents. Using these probabilities, the search space is reduced, obtaining very good solutions in a short time. The method has been tested with two different networks located in France and Chile. The numerical results show that our procedure is viable in practice.
Timetabling Transportation Integer programming Logistic regression Disruption management Railways
http://www.sciencedirect.com/science/article/pii/S0377221711004954
Acuna-Agost, Rodrigo
Michelon, Philippe
Feillet, Dominique
Gueye, Serigne
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:14-202011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:14-20
article
A global optimization procedure for the location of a median line in the three-dimensional space
A global optimization procedure is proposed to find a line in the Euclidean three-dimensional space which minimizes the sum of distances to a given finite set of three-dimensional data points. Although we are using similar techniques as for location problems in two dimensions, it is shown that the problem becomes much harder to solve. However, a problem parameterization as well as lower bounds are suggested whereby we succeeded in solving medium-size instances in a reasonable amount of computing time.
Global optimization Geometric branch-and-bound methods Line location
http://www.sciencedirect.com/science/article/pii/S0377221711004553
Blanquero, Rafael
Carrizosa, Emilio
Schöbel, Anita
Scholz, Daniel
oai:RePEc:eee:ejores:v:211:y:2011:i:3:p:525-5322011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:211:y:2011:i:3:p:525-532
article
Design of progressively censored group sampling plans for Weibull distributions: An optimization problem
Optimization algorithms provides efficient solutions to many statistical problems. Essentially, the design of sampling plans for lot acceptance purposes is an optimization problem with several constraints, usually related to the quality levels required by the producer and the consumer. An optimal acceptance sampling plan is developed in this paper for the Weibull distribution with unknown scale parameter. The proposed plan combines grouping of items, sudden death testing in each group and progressive group removals, and its decision criterion is based on the uniformly most powerful life test. A mixed integer programming problem is first solved for determining the minimum number of failures required and the corresponding acceptance constant. The optimal number of groups is then obtained by minimizing a balanced estimation of the expected test cost. Excellent approximately optimal solutions are also provided in closed-forms. The sampling plan is considerably flexible and allows to save experimental time and cost. In general, our methodology achieves solutions that are quite robust to small variations in the Weibull shape parameter. A numerical example about a manufacturing process of gyroscopes is included for illustration.
Constrained optimization Minimal expected cost Mixed integer programming Operating characteristic function Producer's and consumer's risks Quality control
http://www.sciencedirect.com/science/article/B6VCT-51N228J-1/2/6fa9ba419e406f67b27b447fe9dd4f10
Fernández, Arturo J.
Pérez-González, Carlos J.
Aslam, Muhammad
Jun, Chi-Hyuck
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:45-562011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:45-56
article
Scheduling inspired models for two-dimensional packing problems
We propose two exact algorithms for two-dimensional orthogonal packing problems whose main components are simple mixed-integer linear programming models. Based on the different forms of time representation in scheduling formulations, we extend the concept of multiple time grids into a second dimension and propose a hybrid discrete/continuous-space formulation. By relying on events to continuously locate the rectangles along the strip height, we aim to reduce the size of the resulting mathematical problem when compared to a pure discrete-space model, with hopes of achieving a better computational performance. Through the solution of a set of 29 test instances from the literature, we show that this was mostly accomplished, primarily because the associated search strategy can quickly find good feasible solutions prior to the optimum, which may be very important in real industrial environments. We also provide a comprehensive comparison to seven other conceptually different approaches that have solved the same strip packing problems.
Optimization Integer programming Strip packing Resource-Task Network Spatial grids
http://www.sciencedirect.com/science/article/pii/S0377221711005078
Castro, Pedro M.
Oliveira, José F.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:568-5782011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:568-578
article
Equilibrium analysis of supply chain structures under power imbalance
This paper investigates the implications of channel power on supply chain stability in a setting where multiple suppliers sell substitutable products through a common retailer. Such supply chains have been traditionally analyzed as one- or two-stage Stackelberg non-cooperative games with all suppliers sharing balanced (equal) decision-making power. In this paper, we relax this assumption and formulate game-theoretic models to examine scenarios where one supplier can act as the Stackelberg leader. Consequently, we analyze new supply chain structures and introduce the notion of structure dominance, a novel approach to analyze the performance of supply chains that has practical implications. Thus, a decision maker can employ the concepts of structure dominance to determine whether there exist supply chain scenarios that are more stable than others, i.e., less prone to power reconfigurations, at both agent and group level. We find that power imbalance causes significant declines in supply chain profits, and the more balanced the agents are the higher their profits when demand is linear, regardless of product competition. It develops that neither the Manufacturer Stackelberg nor the Retailer Stackelberg supply chains are stable structures in our generalized setting, but that structures where power is equally split between agents provide for best stability and performance.
Power dominance Supply chain stability Game theory
http://www.sciencedirect.com/science/article/pii/S0377221711004139
Edirisinghe, N.C.P.
Bichescu, B.
Shi, X.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:595-6052011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:595-605
article
Fix-and-optimize heuristics for capacitated lot-sizing with sequence-dependent setups and substitutions
In this paper, we consider a capacitated single-level dynamic lot-sizing problem with sequence-dependent setup costs and times that includes product substitution options. The model is motivated from a real-world production planning problem of a manufacturer of plastic sheets used as an interlayer in car windshields. We develop a mixed-integer programming (MIP) formulation of the problem and devise MIP-based Relax&Fix and Fix&Optimize heuristics. Unlike existing literature, we combine Fix&Optimize with a time decomposition. Also, we develop a specialized substitute decomposition and devise a computation budget allocation scheme for ensuring a uniform, efficient usage of computation time by decompositions and their subproblems. Computational experiments were performed on generated instances whose structure follows that of the considered practical application and which have rather tight production capacities. We found that a Fix&Optimize algorithm with an overlapping time decomposition yielded the best solutions. It outperformed the state-of-the-art approach Relax&Fix and all other tested algorithm variants on the considered class of instances, and returned feasible solutions with neither overtime nor backlogging for all instances. It returned solutions that were on average only 5% worse than those returned by a standard MIP solver after 4Â hours and 19% better than those of Relax&Fix.
Production Heuristics Integer programming Capacitated lot-sizing and scheduling Sequence-dependent setups Substitutions
http://www.sciencedirect.com/science/article/pii/S0377221711004395
Lang, Jan Christian
Shen, Zuo-Jun Max
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:289-3002011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:289-300
article
Telecom service provider portal: Revenue sharing and outsourcing
Early mobile phones only provided voice transmission, for a fee. They have now evolved into voice and online data portals for providing additional services through 3rd party vendors. These service providers (vendors) are given access to a customer base "owned" by the mobile phone companies, for a fee. Typically customers make two payments: to the mobile phone company for phone services and to the 3rd party vendors for specific services bought from them. Variations to the above business model may involve outsourcing the online portal and/or acquiring customers from other independent portals. For these scenarios, we study how the fees for phone service and customer access are established and how they may relate to the prices of vendor services, and which services should be located on the portal - all in a game-theoretic context. Our results prove that it is possible to reorganize revenue flows through an invoicing process that may benefit the mobile network operator more than the other parties. In addition, we establish optimality in terms of the number of vendors on the portal, and determine a rank-ordering of vendors for their inclusion into the portal.
E-commerce Non-cooperative games Pricing Telecommunications
http://www.sciencedirect.com/science/article/pii/S0377221711003869
Chakravarty, Amiya K.
Werner, Adrian S.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:257-2672011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:257-267
article
Dynamic lot-sizing in sequential online retail auctions
Retailers often conduct non-overlapping sequential online auctions as a revenue generation and inventory clearing tool. We build a stochastic dynamic programming model for the seller's lot-size decision problem in these auctions. The model incorporates a random number of participating bidders in each auction, allows for any bid distribution, and is not restricted to any specific price-determination mechanism. Using stochastic monotonicity/stochastic concavity and supermodularity arguments, we present a complete structural characterization of optimal lot-sizing policies under a second order condition on the single-auction expected revenue function. We show that a monotone staircase with unit jumps policy is optimal and provide a simple inequality to determine the locations of these staircase jumps. Our analytical examples demonstrate that the second order condition is met in common online auction mechanisms. We also present numerical experiments and sensitivity analyses using real online auction data.
Auctions/bidding Dynamic programming e-Commerce
http://www.sciencedirect.com/science/article/pii/S0377221711004991
Chen, Xi
Ghate, Archis
Tripathi, Arvind
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:759-7672011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:759-767
article
Portfolio symmetry and momentum
This paper presents a novel theoretical framework to model the evolution of a dynamic portfolio (i.e., a portfolio whose weights vary over time), considering a given investment policy. The framework is based on graph theory and the quantum probability. Embedding the dynamics of a portfolio into a graph, each node of the graph representing a plausible portfolio, we provide the probabilities for a dynamic portfolio to lie on different nodes of the graph, characterizing its optimality in terms of returns. The framework embeds cross-sectional phenomena, such as the momentum effect, in stochastic processes, using portfolios instead of individual stocks. We apply our methodology to an investment policy similar to the momentum strategy of Jegadeesh and Titman (1993). We find that the strategy symmetry is a source of momentum.
(P) Finance Graph theory Momentum Quantum probability Spectral analysis
http://www.sciencedirect.com/science/article/pii/S0377221711004188
Billio, Monica
Calès, Ludovic
Guégan, Dominique
oai:RePEc:eee:ejores:v:204:y:2010:i:3:p:496-5042011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:204:y:2010:i:3:p:496-504
article
Inequalities for the ruin probability in a controlled discrete-time risk process
Ruin probabilities in a controlled discrete-time risk process with a Markov chain interest are studied. To reduce the risk of ruin there is a possibility to reinsure a part or the whole reserve. Recursive and integral equations for ruin probabilities are given. Generalized Lundberg inequalities for the ruin probabilities are derived given a constant stationary policy. The relationships between these inequalities are discussed. To illustrate these results some numerical examples are included.
Risk process Ruin probability Proportional reinsurance Lundberg's inequality
http://www.sciencedirect.com/science/article/B6VCT-4XSJVN5-1/2/f91c6504f68fe0606cae1dfbc4c676ea
Diasparra, M.
Romera, R.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:722-7312011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:722-731
article
Analyzing online B2B exchange markets: Asymmetric cost and incomplete information
This research applies the discriminating auction to analyze the online B2B exchange market in which a single buyer requests multiple items and several suppliers having equal capacity and asymmetric cost submit bids to compete for buyer demand. In the present model, we examine the impact of asymmetric cost and incomplete information on the participants in the market. Given the complete cost information, each supplier randomizes its price and the lower bound of the price range is determined by the highest marginal cost. In addition, the supplier with a lower marginal cost has a larger considered pricing space but ultimately has a smaller equilibrium one than others with higher marginal costs. When each supplier's marginal cost is private information, the lowest possible price is determined by the number of suppliers and the buyer's reservation price. Comparing these two market settings, we find whether IT is beneficial to buyers or suppliers depends on the scale of the bid process and the highest marginal cost. When the number of suppliers and the difference between the highest marginal cost and the buyer's reservation price are sufficiently large, each supplier can gain a higher profit if the marginal costs are private information. On the contrary, when the highest marginal cost approaches the buyer's reservation price, complete cost information benefits the suppliers.
Auctions Economics Game theory Online exchanges Supplier competition
http://www.sciencedirect.com/science/article/pii/S0377221711004504
Li, Yung-Ming
Jhang-Li, Jhih-Hua
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:204-2172011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:204-217
article
Reverse programming the optimal process mean problem to identify a factor space profile
For the manufacturer that intends to reduce the processing costs without sacrificing product quality, the identification of the optimal process mean is a problem frequently revisited. The traditional method to solving this problem involves making assumptions on the process parameter values and then determining the ideal location of the mean based upon various constraints such as cost or the degree of quality loss when a product characteristic deviates from its desired target value. The optimal process mean, however, is affected not only by these settings but also by any shift in the variability of a process, thus making it extremely difficult to predict with any accuracy. In contrast, this paper proposes the use of a reverse programming scheme to determine the relationship between the optimal process mean and the settings within an experimental factor space. By doing so, one may gain increased awareness of the sensitivity and robustness of a process, as well as greater predictive capability in the setting of the optimal process mean. Non-linear optimization programming routines are used from both a univariate and multivariate perspective in order to illustrate the proposed methodology.
Quality management Optimization Response surface methodology Desirability function Optimal process mean
http://www.sciencedirect.com/science/article/pii/S0377221711005108
Goethals, Paul L.
Cho, Byung Rae
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:606-6152011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:606-615
article
Intermittent demand: Linking forecasting to inventory obsolescence
The standard method to forecast intermittent demand is that by Croston. This method is available in ERP-type solutions such as SAP and specialised forecasting software packages (e.g. Forecast Pro), and often applied in practice. It uses exponential smoothing to separately update the estimated demand size and demand interval whenever a positive demand occurs, and their ratio provides the forecast of demand per period. The Croston method has two important disadvantages. First and foremost, not updating after (many) periods with zero demand renders the method unsuitable for dealing with obsolescence issues. Second, the method is positively biased and this is true for all points in time (i.e. considering the forecasts made at an arbitrary time period) and issue points only (i.e. considering the forecasts following a positive demand occurrence only). The second issue has been addressed in the literature by the proposal of an estimator (Syntetos-Boylan Approximation, SBA) that is approximately unbiased. In this paper, we propose a new method that overcomes both these shortcomings while not adding complexity. Different from the Croston method, the new method is unbiased (for all points in time) and it updates the demand probability instead of the demand interval, doing so in every period. The comparative merits of the new estimator are assessed by means of an extensive simulation experiment. The results indicate its superior performance and enable insights to be gained into the linkage between demand forecasting and obsolescence.
Forecasting Intermittent demand Inventory control Obsolescence
http://www.sciencedirect.com/science/article/pii/S0377221711004437
Teunter, Ruud H.
Syntetos, Aris A.
Zied Babai, M.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:161-1682011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:161-168
article
Weighted bankruptcy rules and the museum pass problem
In this paper we introduce and characterize some allocation rules for weighted bankruptcy problems. We illustrate the relevancy of weighted bankruptcy by applying it to analyse the museum pass problem, introduced by Ginsburgh and Zang (2003). This application is completed with the analysis of real data for the "Card Musei" of the Municipality of Genova.
Game theory Bankruptcy Weighted rule Axiomatic characterization Museum pass problem
http://www.sciencedirect.com/science/article/pii/S0377221711004589
Casas-Méndez, Balbina
Fragnelli, Vito
García-Jurado, Ignacio
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:716-7212011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:716-721
article
Generalizing cross redundancy in data envelopment analysis
Lee and Choi (2010) proved that a cross redundant output in a CCR or BCC DEA study is unnecessary and can be eliminated from the model without affecting the results of the study. A cross redundant output, as characterized by Lee and Choi, can be expressed as a specially constrained linear combination of both some outputs and some inputs. This article extends the contributions of Lee and Choi (2010) in at least three ways: (i) by adding precision and clarity to some of their definitions; (ii) by introducing specific definitions that complement the ones in their paper; and (iii) by conducting some additional analysis on the impact of the presence of other types of linear dependencies among the inputs and outputs of a DEA model. One reason that it is important to identify and remove cross redundant inputs or outputs from DEA models is that the computational burden of the DEA study is decreased, especially in large applications.
Data envelopment analysis DEA Cross redundancy
http://www.sciencedirect.com/science/article/pii/S0377221711004450
López, Francisco J.
oai:RePEc:eee:ejores:v:201:y:2010:i:3:p:791-7982011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:201:y:2010:i:3:p:791-798
article
On the link between Markovian trees and tree-structured Markov chains
In this paper, we describe a link between Markovian binary trees (MBT) and tree-like quasi-birth-and-death processes (TLQBD) by associating a specific TLQBD to each MBT. The algorithms to compute the matrices Gk in the TLQBD then correspond to the algorithms calculating the extinction probability vector of the MBT. This parallelism leads to a new quadratic algorithm, based on the Newton iteration method, which converges to the extinction probability of an MBT. We also present a one-to-one correspondence between a general Markovian tree (GMT) and a scalar tree-structured M/G/1-type Markov chain. This allows us to prove the equivalence between the main result on the positive recurrence, null recurrence or transience of a scalar tree-structured M/G/1-type Markov chain and the criticality of a GMT.
Stochastic processes Markovian multi-type branching processes Markovian trees Tree-like quasi-birth-and-death processes Extinction probability Newton's iteration
http://www.sciencedirect.com/science/article/B6VCT-4W1SRPD-1/2/f9e60fe85929b348860489e589725dc8
Hautphenne, Sophie
Houdt, Benny Van
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:136-1482011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:136-148
article
Consignment contracts with retail competition
Consignment contracts have been widely employed in many industries. Under such contracts, items are sold at a retailer's but the supplier retains the full ownership of the inventory until purchased by consumers; the supplier collects payment from the retailer based on actual units sold. We investigate how competition among retailers influences the supply chain decisions and profits under different consignment arrangements, namely a consignment price contract and a consignment contract with revenue share. First, we investigate how these two consignment contracts and a price only contract compare from the perspective of each supply chain partner. We find that the retailers benefit more from a consignment price contract than from a consignment contract with revenue share or a price only contract, regardless of the level of retailer differentiation. The supplier's most beneficial contact, however, critically depends upon the level of retailer differentiation: a consignment contract with revenue share is preferable for the supplier if retailer differentiation is strong; otherwise a consignment price contract is preferable. Second, we study how retailer differentiation affects the profits of all supply chain partners. We find that less retailer differentiation improves the supplier's profit for both types of consignment contract. Moreover, less retailer differentiation improves profits of the retailers in a consignment price contract, but not necessarily in a consignment contract with revenue share.
Supply chain Consignment Retail competition
http://www.sciencedirect.com/science/article/pii/S0377221711005133
Adida, Elodie
Ratisoontorn, Nantaporn
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:21-242011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:21-24
article
Locating a competitive facility in the plane with a robustness criterion
A new model for locating a competitive facility in the plane in a robust way is presented and embedded in the literature on robustness in facility location. Its mathematical properties are investigated and new sharp bounds for a deterministic method that guarantees the global optimum are derived and evaluated.
Robustness Facility location Robust solutions Competitive location Huff model dc programming
http://www.sciencedirect.com/science/article/pii/S0377221711004887
Blanquero, R.
Carrizosa, E.
Hendrix, E.M.T.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:457-4722011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:457-472
article
A taxonomy and review of the fuzzy data envelopment analysis literature: Two decades in the making
Data envelopment analysis (DEA) is a methodology for measuring the relative efficiencies of a set of decision making units (DMUs) that use multiple inputs to produce multiple outputs. Crisp input and output data are fundamentally indispensable in conventional DEA. However, the observed values of the input and output data in real-world problems are sometimes imprecise or vague. Many researchers have proposed various fuzzy methods for dealing with the imprecise and ambiguous data in DEA. In this study, we provide a taxonomy and review of the fuzzy DEA methods. We present a classification scheme with four primary categories, namely, the tolerance approach, the [alpha]-level based approach, the fuzzy ranking approach and the possibility approach. We discuss each classification scheme and group the fuzzy DEA papers published in the literature over the past 20 years. To the best of our knowledge, this paper appears to be the only review and complete source of references on fuzzy DEA.
Data envelopment analysis Fuzzy sets Tolerance approach [alpha]-Level based approach Fuzzy ranking approach Possibility approach
http://www.sciencedirect.com/science/article/pii/S0377221711001329
Hatami-Marbini, Adel
Emrouznejad, Ali
Tavana, Madjid
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:665-6732011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:665-673
article
The signal model: A model for competing risks of opportunistic maintenance
This paper presents a competing risks reliability model for a system that releases signals each time its condition deteriorates. The released signals are used to inform opportunistic maintenance. The model provides a framework for the determination of the underlying system lifetime from right-censored data, without requiring explicit assumptions about the type of censoring to be made. The parameters of the model are estimated from observational data by using maximum likelihood estimation. We illustrate the estimation process through a simulation study. The proposed signal model can be used to support decision-making in optimising preventive maintenance: at a component level, estimates of the underlying failure distribution can be used to identify the critical signal that would trigger maintenance of the individual component; at a multi-component system level, accurate estimates of the component underlying lifetimes are important when making general maintenance decisions. The benefit of good estimation from censored data, when adequate knowledge about the dependence structure is not available, may justify the additional data collection cost in cases where full signal data is not available.
Reliability Maintenance Competing risks Statistical inference
http://www.sciencedirect.com/science/article/pii/S0377221711004413
Bedford, Tim
Dewan, Isha
Meilijson, Isaac
Zitrou, Athena
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:485-4922011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:485-492
article
An interior proximal method in vector optimization
This paper studies the vector optimization problem of finding weakly efficient points for maps from to , with respect to the partial order induced by a closed, convex, and pointed cone , with nonempty interior. We develop for this problem an extension of the proximal point method for scalar-valued convex optimization problem with a modified convergence sensing condition that allows us to construct an interior proximal method for solving VOP on nonpolyhedral set.
Interior point methods Vector optimization C-convex Positively lower semicontinuous
http://www.sciencedirect.com/science/article/pii/S0377221711004115
Villacorta, Kely D.V.
Oliveira, P. Roberto
oai:RePEc:eee:ejores:v:207:y:2010:i:1:p:420-4332011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:207:y:2010:i:1:p:420-433
article
Optimization of R&D project portfolios under endogenous uncertainty
Project portfolio management deals with the dynamic selection of research and development (R&D) projects and determination of resource allocations to these projects over a planning period. Given the uncertainties and resource limitations over the planning period, the objective is to maximize the expected total discounted return or the expectation of some other function for all projects over a long time horizon. We develop a detailed formal description of this problem and the corresponding decision process, and then model it as a multistage stochastic integer program with endogenous uncertainty. Accounting for this endogeneity, we propose an efficient solution approach for the resulting model, which involves the development of a formulation technique that is amenable to scenario decomposition. The proposed solution algorithm also includes an application of the sample average approximation method, where the sample problems are solved through Lagrangian relaxation and a new lower bounding heuristic. The performance of the overall solution procedure is demonstrated using several implementations of the proposed approach.
OR in research and development Project portfolio Technology management R&D Multistage stochastic programming Endogenous uncertainty
http://www.sciencedirect.com/science/article/B6VCT-504127Y-1/2/e3d8fbc74177b8efd6bbad180f34317b
Solak, Senay
Clarke, John-Paul B.
Johnson, Ellis L.
Barnes, Earl R.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:105-1142011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:105-114
article
Optimal operating strategy for a long-haul liner service route
This paper proposes an optimal operating strategy problem arising in liner shipping industry that aims to determine service frequency, containership fleet deployment plan, and sailing speed for a long-haul liner service route. The problem is formulated as a mixed-integer nonlinear programming model that cannot be solved efficiently by the existing solution algorithms. In view of some unique characteristics of the liner shipping operations, this paper proposes an efficient and exact branch-and-bound based [epsilon]-optimal algorithm. In particular, a mixed-integer nonlinear model is first developed for a given service frequency and ship type; two linearization techniques are subsequently presented to approximate this model with a mixed-integer linear program; and the branch-and-bound approach controls the approximation error below a specified tolerance. This paper further demonstrates that the branch-and-bound based [epsilon]-optimal algorithm obtains a globally optimal solution with the predetermined relative optimality tolerance [epsilon] in a finite number of iterations. The case study based on an existing long-haul liner service route shows the effectiveness and efficiency of the proposed solution method.
Logistics Liner shipping Sailing speed Branch-and-bound
http://www.sciencedirect.com/science/article/pii/S0377221711005054
Meng, Qiang
Wang, Shuaian
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:268-2802011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:268-280
article
Customer rebates and retailer incentives in the presence of competition and price discrimination
Promotions are important tools for matching supply and demand in many industries. In the United States automotive industry, promotions are frequently offered, which may be given directly to customers (rebates) or given to dealers (incentives) to stimulate demand. We analyze the performance of customer rebate and retailer incentive promotions under competition. We study a setting with two manufacturers making simultaneous pricing and promotion decisions, and with two price-discriminating retailers as Stackelberg followers making simultaneous order quantity decisions. In the benchmark case with no promotions, we characterize the equilibria in closed form. We find that retailer incentives can be used by manufacturers to simultaneously improve each of their profits but can potentially lead to lower retailer profits. When manufacturers use customer rebates, we show that a manufacturer is able to decrease the profit of her competitor while increasing her own profit, although she is also at risk for her competitor to use rebates in a similar fashion. Unlike the monopoly case where the manufacturers are always better off with retailer incentives, customer rebates can be more profitable under some cases in the presence of competition. Using numerical examples we generate insights on the manufacturers' preference of promotions in different market settings.
Retailer incentives Customer rebates Competition Automotive industry First-degree price discrimination
http://www.sciencedirect.com/science/article/pii/S0377221711003195
Demirag, Ozgun Caliskan
Keskinocak, Pinar
Swann, Julie
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:616-6262011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:616-626
article
Manufacturing performance measurement and target setting: A data envelopment analysis approach
Manufacturing decision makers have to deal with a large number of reports and metrics for evaluating the performance of manufacturing systems. Since the metrics provide different and at times conflicting assessments, it is hard for the manufacturing decision makers to track and improve overall manufacturing system performance. This research presents a data envelopment analysis (DEA) based approach for performance measurement and target setting of manufacturing systems. The approach is applied to two different manufacturing environments. The performance peer groups identified using DEA are utilized to set performance targets and to guide performance improvement efforts. The DEA scores are checked against past process modifications that led to identified performance changes. Limitations of the DEA based approach are presented when considering measures that are influenced by factors outside of the control of the manufacturing decision makers. The potential of a DEA based generic performance measurement approach for manufacturing systems is provided.
Manufacturing Performance measurement Target setting Data envelopment analysis
http://www.sciencedirect.com/science/article/pii/S037722171100453X
Jain, Sanjay
Triantis, Konstantinos P.
Liu, Shiyong
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:703-7152011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:703-715
article
An innovative orders-of-magnitude approach to AHP-based mutli-criteria decision making: Prioritizing divergent intangible humane acts
An innovative Analytic Hierarchy Process-based structure is developed to capture the relationship between various levels of activities contributed by people to society. Physical objects have widespread extension and degrees of importance that often differ by many orders of magnitude. Similarly, mental thoughts and criteria occur in widely heterogeneous entities that have to be sorted and arranged into homogeneous groups of few elements in each group so that one can evaluate the relationships among them accurately, from the smallest to the largest. It is through such a framework for organizing factors with smooth transition that it is possible to derive reliable priorities from expert judgments. The proposed model enables one to make decisions and allocate resources in as detailed and fine a way as possible. In addition to the traditional approach of structuring criteria into multiple clusters, the alternatives of a decision are also organized into the lowest multiple levels of that hierarchy. This arrangement and evaluation of alternatives differs from one criterion to another, which adds to the complexity of the undertaking when the alternatives are heterogeneous. The coherent approach to structuring complex decisions with the Analytic Hierarchy Process enables one to transcend the complexity of dealing in a scientific way with the problem of widespread orders of magnitude of criteria and alternatives in a complex decision. When the magnitudes are actually very small or very large, the accuracy of rating alternatives one at a time instead of comparing them in pairs involves much guessing, and can lead to a questionable outcome. Alternatively, comparisons, which are necessary for the measurement of intangibles, have greater and better justified accuracy.
Decision support structure Multivariate relative measurement Intangibles AHP Monetary value
http://www.sciencedirect.com/science/article/pii/S0377221711004449
Saaty, Thomas L.
Shang, Jennifer S.
oai:RePEc:eee:ejores:v:195:y:2009:i:1:p:75-882011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:195:y:2009:i:1:p:75-88
article
The dynamic frequency assignment problem
In this paper, we consider a frequency assignment problem occurring in a military context. The main originality of the problem pertains to its dynamic dimension: new communications requiring frequency assignments need to be established throughout a battlefield deployment. The problem resolution framework decomposes into three phases: assignment of an initial kernel of communications, dynamic assignment of new communication links and a repair process when no assignment is possible. Different solution methods are proposed and extensive computational experiments are carried out on realistic instances.
Frequency assignment Dynamic problem Heuristics Tabu search and consistent neighborhood Branch&Bound
http://www.sciencedirect.com/science/article/B6VCT-4RR8YR5-5/2/50579c934e2146544df4a3a91a3ec5ea
Dupont, Audrey
Linhares, Andréa Carneiro
Artigues, Christian
Feillet, Dominique
Michelon, Philippe
Vasquez, Michel
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:493-5002011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:493-500
article
Solving discrete systems of nonlinear equations
We study the existence problem of a zero point of a function defined on a finite set of elements of the integer lattice of the n-dimensional Euclidean space . It is assumed that the set is integrally convex, which implies that the convex hull of the set can be subdivided in simplices such that every vertex is an element of and each simplex of the triangulation lies in an n-dimensional cube of size one. With respect to this triangulation we assume that the function satisfies some property that replaces continuity. Under this property and some boundary condition the function has a zero point. To prove this we use a simplicial algorithm that terminates with a zero point within a finite number of iterations. The standard technique of applying a fixed point theorem to a piecewise linear approximation cannot be applied, because the 'continuity property' is too weak to assure that a zero point of the piecewise linear approximation induces a zero point of the function itself. We apply the main existence result to prove the existence of a pure Cournot-Nash equilibrium in a Cournot oligopoly model. We further obtain a discrete analogue of the well-known Borsuk-Ulam theorem and a theorem for the existence of a solution for the discrete nonlinear complementarity problem.
Discrete system of equations Triangulation Simplicial algorithm Fixed point Zero point
http://www.sciencedirect.com/science/article/pii/S0377221711004498
van der Laan, Gerard
Talman, Dolf
Yang, Zaifu
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:149-1602011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:149-160
article
Optimizing yard assignment in an automotive transshipment terminal
This paper studies a yard management problem in an automotive transshipment terminal. Groups of cars arrive to and depart from the terminal in a given planning period. These groups must be assigned to parking rows under some constraints resulting from managerial rules. The main objective is the minimization of the total handling time. Model extensions to handle application specific issues such as a rolling horizon and a manpower leveling objective are also discussed. The main features of the problem are modeled as an integer linear program. However, solving this formulation by a state-of-the-art solver is impractical. In view of this, we develop a metaheuristic algorithm based on the adaptive large neighborhood search framework. Computational results on real-life data show the efficacy of the proposed metaheuristic algorithm.
Logistics Yard management Automotive transshipment terminal Adaptive large neighborhood search
http://www.sciencedirect.com/science/article/pii/S0377221711005376
Cordeau, Jean-François
Laporte, Gilbert
Moccia, Luigi
Sorrentino, Gregorio
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:169-1802011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:169-180
article
A Bayesian approach to the triage problem with imperfect classification
A collection of jobs (or customers, or patients) wait impatiently for service. Each has a random lifetime during which it is available for service. Should this lifetime expire before its service starts then it leaves unserved. Limited resources mean that it is only possible to serve one job at a time. We wish to schedule the jobs for service to maximise the total number served. In support of this objective all jobs are subject to an initial triage, namely an assessment of both their urgency and of their service requirement. This assessment is subject to error. We take a Bayesian approach to the uncertainty generated by error prone triage and discuss the design of heuristic policies for scheduling jobs for service to maximise the Bayes' return (mean number of jobs served). We identify problem features for which a high price is paid in number of services lost for poor initial triage and for which improvements in initial job assessment yield significant improvements in service outcomes. An analytical upper bound for the cost of imperfect classification is developed for exponentially distributed lifetime cases.
Dynamic programming Bayes sequential decision problem Imperfect classification Stochastic scheduling Optimal service policy
http://www.sciencedirect.com/science/article/pii/S0377221711004929
Li, Dong
Glazebrook, Kevin D.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:644-6552011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:644-655
article
Simulation metamodeling with dynamic Bayesian networks
This paper presents a novel approach to simulation metamodeling using dynamic Bayesian networks (DBNs) in the context of discrete event simulation. A DBN is a probabilistic model that represents the joint distribution of a sequence of random variables and enables the efficient calculation of their marginal and conditional distributions. In this paper, the construction of a DBN based on simulation data and its utilization in simulation analyses are presented. The DBN metamodel allows the study of the time evolution of simulation by tracking the probability distribution of the simulation state over the duration of the simulation. This feature is unprecedented among existing simulation metamodels. The DBN metamodel also enables effective what-if analysis which reveals the conditional evolution of the simulation. In such an analysis, the simulation state at a given time is fixed and the probability distributions representing the state at other time instants are updated. Simulation parameters can be included in the DBN metamodel as external random variables. Then, the DBN offers a way to study the effects of parameter values and their uncertainty on the evolution of the simulation. The accuracy of the analyses allowed by DBNs is studied by constructing appropriate confidence intervals. These analyses could be conducted based on raw simulation data but the use of DBNs reduces the duration of repetitive analyses and is expedited by available Bayesian network software. The construction and analysis capabilities of DBN metamodels are illustrated with two example simulation studies.
Simulation Dynamic Bayesian networks Discrete event simulation Simulation metamodeling
http://www.sciencedirect.com/science/article/pii/S0377221711004127
Poropudas, Jirka
Virtanen, Kai
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:732-7382011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:732-738
article
A probability-mapping algorithm for calibrating the posterior probabilities: A direct marketing application
Calibration refers to the adjustment of the posterior probabilities output by a classification algorithm towards the true prior probability distribution of the target classes. This adjustment is necessary to account for the difference in prior distributions between the training set and the test set. This article proposes a new calibration method, called the probability-mapping approach. Two types of mapping are proposed: linear and non-linear probability mapping. These new calibration techniques are applied to 9 real-life direct marketing datasets. The newly-proposed techniques are compared with the original, non-calibrated posterior probabilities and the adjusted posterior probabilities obtained using the rescaling algorithm of Saerens et al. (2002). The results recommend that marketing researchers must calibrate the posterior probabilities obtained from the classifier. Moreover, it is shown that using a 'simple' rescaling algorithm is not a first and workable solution, because the results suggest applying the newly-proposed non-linear probability-mapping approach for best calibration performance.
Data mining Decision support systems Direct marketing Response modeling Calibration
http://www.sciencedirect.com/science/article/pii/S0377221711004528
Coussement, Kristof
Buckinx, Wouter
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:683-6962011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:683-696
article
Efficient space-filling and non-collapsing sequential design strategies for simulation-based modeling
Simulated computer experiments have become a viable cost-effective alternative for controlled real-life experiments. However, the simulation of complex systems with multiple input and output parameters can be a very time-consuming process. Many of these high-fidelity simulators need minutes, hours or even days to perform one simulation. The goal of global surrogate modeling is to create an approximation model that mimics the original simulator, based on a limited number of expensive simulations, but can be evaluated much faster. The set of simulations performed to create this model is called the experimental design. Traditionally, one-shot designs such as the Latin hypercube and factorial design are used, and all simulations are performed before the first model is built. In order to reduce the number of simulations needed to achieve the desired accuracy, sequential design methods can be employed. These methods generate the samples for the experimental design one by one, without knowing the total number of samples in advance. In this paper, the authors perform an extensive study of new and state-of-the-art space-filling sequential design methods. It is shown that the new sequential methods proposed in this paper produce results comparable to the best one-shot experimental designs available right now.
Regression Design of computer experiments Experimental design Sequential design Space-filling
http://www.sciencedirect.com/science/article/pii/S0377221711004577
Crombecq, K.
Laermans, E.
Dhaene, T.
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:281-2882011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:281-288
article
The decision to raise firm value through a sports-business exchange: How much are Real Madrid's goals worth to its president's company's goals?
Global brands emerging from the world of sports are becoming commonplace, and firms invest in the realm of sports, usually through sponsorship initiatives, to get a link with these global brands. Over and above just a mere business link, what if a company makes a personal commitment to get into the core of a renowned, celebrated sports team? This article provides managers with a procedure to analyze, in a weekly basis, how valuable this type of decision is. A conceptual model shows that the personal involvement of a firm's figurehead in a first-class sports club can impact positively on firm value if the person is doing well in the task s/he is entrusted with by the club. The empirical application to the soccer club Real Madrid, over 1,409Â days and 215 matches, finds that the club's performance on the field has a significant impact on the economic returns of its president's company, with asymmetrical effects on firm value in a "loss aversion" pattern, that is, lost matches have a greater effect on firm value than games won.
Decision analysis Sports-business exchange Brand equity Firm value Loss aversion
http://www.sciencedirect.com/science/article/pii/S0377221711003766
Nicolau, Juan L.
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:579-5872011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:579-587
article
Joint logistics and financial services by a 3PL firm
Integrated logistics and financial services have been practiced by third party logistics (3PL) firms for years; however, the literature has been silent on the value of 3PL firms as credit providers in budget-constrained supply chains. This paper investigates an extended supply chain model with a supplier, a budget-constrained retailer, a bank, and a 3PL firm, in which the retailer has insufficient initial budget and may borrow or obtain trade credit from either a bank (traditional role) or a 3PL firm (control role). Our analysis indicates that the control role model yields higher profits not only for the 3PL firm but also for the supplier, the retailer, and the entire supply chain. In comparison with a supplier credit model where the supplier provides the trade credit, the control role model yields a better performance for the supply chain as long as the 3PL firm's marginal profit is greater than that of the supplier. We further demonstrate that, for all players, both the control role and supplier credit models can outperform the classic newsvendor model without budget constraint.
Third party logistics (3PL) Budget-constrained retailer Supply chain Financial service
http://www.sciencedirect.com/science/article/pii/S0377221711004164
Chen, Xiangfeng
Cai, Gangshu (George)
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:526-5352011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:526-535
article
A tree search method for the container loading problem with shipment priority
This paper addresses a special kind of container loading problem with shipment priority. We present a tree search method, which is based on a greedy heuristic. In the greedy heuristic, blocks made up of identical items with the same orientation are selected for packing into a container. Five evaluation functions are proposed for block selection, and the different blocks selected by each evaluation function constitute the branches of the search tree. A method of space splitting and merging is also embedded in the algorithm to facilitate efficient use of the container space. In addition, the proposed algorithm covers an important constraint called shipment priority to solve practical problems. The validity of the proposed algorithm is examined by comparing the present results with those of published algorithms using the same data.
Packing Container loading problem Heuristic Tree search Shipment priority
http://www.sciencedirect.com/science/article/pii/S0377221711003699
Ren, Jidong
Tian, Yajie
Sawaragi, Tetsuo
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:301-3082011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:301-308
article
Pro-efficiency: Data speak more than technical efficiency
In this study, we demonstrate a new method of addressing efficiency in situations in which only the input and output data are available, while evaluating efficiency more accurately than is possible via the ordinary data envelopment analysis (DEA). Technical efficiency is important, but management always desires information regarding the profit aspects of performance. In practice, however, the precise price data are frequently unavailable. Is it possible to approximate profit efficiency in the absence of price information? We develop a simple and usable approach, a linear programming model, for the evaluation of profit efficiency. Our approach implies technical efficiency in DEA and gives rise to the upper bound of profit efficiency, referred to as pro-efficiency. We also report a successful application of our method to a securities company, in which a comparison of the actual profit data and the pro-efficiency measures of the company's branches demonstrates a significant correlation.
Efficiency measurement DEA Profit efficiency Securities company
http://www.sciencedirect.com/science/article/pii/S0377221711004097
Sam Park, K.
Cho, Jin-Wan
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:181-1872011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:181-187
article
Should European gamblers play lotto in the USA?
Any jackpot building game is designed to have a negative expected return for the gambler, but it can be profitable under certain circumstances. Previous studies have shown that the purchase of a single ticket of US-American state lotteries is sometimes a gamble with a positive expected value. Lottery winnings are not taxed in Europe, which suggests that the profitability of European games may be even higher. We present an exact formula for the calculation of the expected value of a single lotto ticket and find European lottery drawings to be far less profitable for the gambler compared to the US-American lotto market. Those US lotteries that generate profitable drawings are not characterized by higher redistribution rates or by their specific rules, but by the purchasing behavior of the gamblers. These gamblers buy far fewer tickets (per capita) and they barely react to increasing jackpots, even though the jackpots are large enough to cause positive expected winnings.
Applied probability Gambling Lottery
http://www.sciencedirect.com/science/article/pii/S0377221711004978
Hofer, Vera
Leitner, Johannes
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:739-7482011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:739-748
article
An adaptive evaluation mechanism for online traders
Economic agents in electronic markets generally consider reputation to be a significant factor in selecting trading partners. Most traditional online businesses publish reputation profile for traders that reflect average of the ratings received in previous transactions. Because of the importance of these ratings, there is an incentive for traders to partake in strategic behavior (for example shilling) to artificially inflate their rating. It is therefore important for an online business to be able to provide a robust estimate of a trader's reputation that is not easily affected by strategic behavior or noisy ratings. This paper proposes such an adaptive ratings-based reputation model. The model is based on a trader's transaction history, witness testimony, and other weighting factors. Learning is integrated to make the ratings model adaptive and robust in a dynamic environment. To validate the proposed model and to demonstrate the significance of its constructs, a multi-agent system is built to simulate the interactions among buyers and sellers in an electronic marketplace. The performance of the proposed model is compared to that of the reputation model used in most online marketplaces like Amazon, and to Huynh's model proposed in the literature.
E-commerce Reputation mechanism Online ratings Simulation Multi-agent system
http://www.sciencedirect.com/science/article/pii/S0377221711004565
You, Liangjun
Sikora, Riyaz
oai:RePEc:eee:ejores:v:214:y:2011:i:3:p:697-7022011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:214:y:2011:i:3:p:697-702
article
On the set of imputations induced by the k-additive core
An extension to the classical notion of core is the notion of k-additive core, that is, the set of k-additive games which dominate a given game, where a k-additive game has its Möbius transform (or Harsanyi dividends) vanishing for subsets of more than k elements. Therefore, the 1-additive core coincides with the classical core. The advantages of the k-additive core is that it is never empty once kÂ [greater-or-equal, slanted]Â 2, and that it preserves the idea of coalitional rationality. However, it produces k-imputations, that is, imputations on individuals and coalitions of at most k individuals, instead of a classical imputation. Therefore one needs to derive a classical imputation from a k-order imputation by a so-called sharing rule. The paper investigates what set of imputations the k-additive core can produce from a given sharing rule.
Game theory Core k-Additive game Selectope
http://www.sciencedirect.com/science/article/pii/S0377221711004152
Grabisch, Michel
Li, Tong
oai:RePEc:eee:ejores:v:215:y:2011:i:1:p:97-1042011-08-25RePEc:eee:ejores
RePEc:eee:ejores:v:215:y:2011:i:1:p:97-104
article
A comprehensive extension of optimal ordering policy for stock-dependent demand under progressive payment scheme
In a recent paper, Soni and Shah (2008) presented an inventory model with a stock-dependent demand under progressive payment scheme, assuming zero ending-inventory and adopting a cost-minimization objective. However, with a stock-dependent demand a non-zero ending stock may increase profits resulting from the increased demand. This work is motivated by Soni and Shah's (2008) paper extending their model to allow for: (1) a non-zero ending-inventory, (2) a profit-maximization objective, (3) a limited inventory capacity and (4) deteriorating items with a constant deterioration rate. For the resulted model sufficient conditions for the existence and uniqueness of the optimal solution are provided. Finally, several economic interpretations of the theoretical results are also given.
Inventory Stock-dependent demand Progressive payment scheme Deteriorating items
http://www.sciencedirect.com/science/article/pii/S0377221711005042
Teng, Jinn-Tsair
Krommyda, Iris-Pandora
Skouri, Konstantina
Lou, Kuo-Ren
oai:RePEc:eee:ejores:v:123:y:2000:i:1:p:42-602009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:123:y:2000:i:1:p:42-60
article
Production lot sizing in failure prone two-stage serial systems
http://www.sciencedirect.com/science/article/B6VCT-3YS344J-4/2/2748fae7c9ff00f6dd80c9be38d35480
Lee, S. D.
Rung, J. M.
oai:RePEc:eee:ejores:v:3:y:1979:i:6:p:450-4582009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:3:y:1979:i:6:p:450-458
article
Operational gaming in action research
http://www.sciencedirect.com/science/article/B6VCT-48NBHV5-2DH/2/0ef20d025371617066ddd88684958e2f
Eden, Colin
Smithin, Tim
oai:RePEc:eee:ejores:v:181:y:2007:i:1:p:59-752009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:181:y:2007:i:1:p:59-75
article
Comparison of agent-based scheduling to look-ahead heuristics for real-time transportation problems
http://www.sciencedirect.com/science/article/B6VCT-4KV3XT6-1/2/0a71abb449f8943fb58fa984d38a7317
Mes, Martijn
van der Heijden, Matthieu
van Harten, Aart
oai:RePEc:eee:ejores:v:57:y:1992:i:2:p:231-2422009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:57:y:1992:i:2:p:231-242
article
A multiattribute decision-theoretic approach for the layout design problem
http://www.sciencedirect.com/science/article/B6VCT-48MYGHP-1D/2/455d768ee30594eefce9c8d5fca8277c
Sarin, Subhash C.
Loharjun, Pasu
Malmborg, Charles J.
Krishnakumar, Bhaskaran
oai:RePEc:eee:ejores:v:44:y:1990:i:3:p:373-3822009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:44:y:1990:i:3:p:373-382
article
Efficiency and proper efficiency in nonlinear vector maximum problems
http://www.sciencedirect.com/science/article/B6VCT-48VW7G1-8K/2/5851636335348b7f631b7603bfe4dbdf
Gulati, T. R.
Islam, M. A.
oai:RePEc:eee:ejores:v:163:y:2005:i:1:p:20-292009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:163:y:2005:i:1:p:20-29
article
How did the Fed react to the 1990s stock market bubble? Evidence from an extended Taylor rule
http://www.sciencedirect.com/science/article/B6VCT-4BT1TW5-1/2/ea588e7c56321650d2bc979058983084
Hayford, M. D.
Malliaris, A. G.
oai:RePEc:eee:ejores:v:159:y:2004:i:1:p:83-942009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:159:y:2004:i:1:p:83-94
article
A mixed integer formulation for maximal covering by inclined parallelograms
http://www.sciencedirect.com/science/article/B6VCT-49CT1N5-2/2/0089be63ad46fea50bea626a6c20a096
Younies, Hassan
Wesolowsky, George O.
oai:RePEc:eee:ejores:v:181:y:2007:i:3:p:1425-14262009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:181:y:2007:i:3:p:1425-1426
article
Managing uncertainty in decision support models
http://www.sciencedirect.com/science/article/B6VCT-4K4WH30-1/2/f791b96ae732d80f2551976c0da97465
Antunes, Carlos Henggeler
Dias, Luis C.
oai:RePEc:eee:ejores:v:157:y:2004:i:1:p:16-272009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:157:y:2004:i:1:p:16-27
article
Linear semi-openness and the Lyusternik theorem
http://www.sciencedirect.com/science/article/B6VCT-49SWD4C-7/2/d9d2bc2279db1d32f39b24aa39d0530f
Puhl, H.
Schirotzek, W.
oai:RePEc:eee:ejores:v:186:y:2008:i:1:p:276-2872009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:186:y:2008:i:1:p:276-287
article
The effect of forecasting and information sharing in SCM for multi-generation products
http://www.sciencedirect.com/science/article/B6VCT-4N3GFHB-B/2/86c924d08e3c708aba47f43c9206dfbe
Sohn, So Young
Lim, Michael
oai:RePEc:eee:ejores:v:44:y:1990:i:2:p:134-1442009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:44:y:1990:i:2:p:134-144
article
Average-case analysis of cutting and packing in two dimensions
http://www.sciencedirect.com/science/article/B6VCT-48MYHSS-F0/2/72af9c4b180618ab661bf8eef152a035
Coffman, E. G.
Shor, P. W.
oai:RePEc:eee:ejores:v:160:y:2005:i:1:p:227-2312009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:160:y:2005:i:1:p:227-231
article
On the complexity of minmax regret linear programming
http://www.sciencedirect.com/science/article/B6VCT-4B0WMX1-3/2/dabdf449bb555c833d1bfa998261d83f
Averbakh, Igor
Lebedev, Vasilij
oai:RePEc:eee:ejores:v:182:y:2007:i:3:p:1399-14112009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:182:y:2007:i:3:p:1399-1411
article
Managing a portfolio of long term service agreements
http://www.sciencedirect.com/science/article/B6VCT-4MH2BWV-1/2/a970746eb8cc54480d653df26fcc3822
Bollapragada, Srinivas
Gupta, Aparna
Lawsirirat, Chaipat
oai:RePEc:eee:ejores:v:161:y:2005:i:3:p:704-7202009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:161:y:2005:i:3:p:704-720
article
Robust scheduling of parallel machines with sequence-dependent set-up costs
http://www.sciencedirect.com/science/article/B6VCT-4B429TX-4/2/738424dfb0b7dd4bcc609929c3c75ad3
Anglani, Alfredo
Grieco, Antonio
Guerriero, Emanuela
Musmanno, Roberto
oai:RePEc:eee:ejores:v:15:y:1984:i:3:p:400-4072009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:15:y:1984:i:3:p:400-407
article
A decision process over variables and their Issue: Two-phase optimality conditions
http://www.sciencedirect.com/science/article/B6VCT-48NBGD8-1W1/2/550d9b237f0675ce2a36fce75eafa384
Friedman, Moshe F.
Winter, Jeffrey L.
oai:RePEc:eee:ejores:v:11:y:1982:i:1:p:55-592009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:11:y:1982:i:1:p:55-59
article
Telephone operator scheduling with a fixed number of operators
http://www.sciencedirect.com/science/article/B6VCT-4H9PHHN-9/2/7600c89ccc99c33ff4666b620e90ff89
van Oudheusden, Dirk L.
Wen-Jenq, Wu
oai:RePEc:eee:ejores:v:115:y:1999:i:2:p:217-2182009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:115:y:1999:i:2:p:217-218
article
Editorial
http://www.sciencedirect.com/science/article/B6VCT-3YYT6RC-1/2/24888d1b28c89a95e41b2d967b1df733
Unknown
oai:RePEc:eee:ejores:v:37:y:1988:i:3:p:409-4082009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:37:y:1988:i:3:p:409-408
article
On "transient solutions for some exhaustive M/G/1 queues with generalized independent vacations" by D.L. Minh
http://www.sciencedirect.com/science/article/B6VCT-48VW782-54/2/a551be16d50629875922604d41783514
Loris-Teghem, Jacqueline
oai:RePEc:eee:ejores:v:176:y:2007:i:1:p:361-3732009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:176:y:2007:i:1:p:361-373
article
Non-normality and the variable parameters control charts
http://www.sciencedirect.com/science/article/B6VCT-4H8MNWP-8/2/78728cdf83d9c2102f1c28ef35d17d7e
Lin, Yu-Chang
Chou, Chao-Yu
oai:RePEc:eee:ejores:v:87:y:1995:i:3:p:464-4682009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:87:y:1995:i:3:p:464-468
article
OR practice in South Africa
http://www.sciencedirect.com/science/article/B6VCT-40324HT-D/2/067fa76ab578c62e59a422fa72ba38ec
Stewart, Theodor J.
oai:RePEc:eee:ejores:v:11:y:1982:i:1:p:77-812009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:11:y:1982:i:1:p:77-81
article
Spares allocation in the presence of uncertainty
http://www.sciencedirect.com/science/article/B6VCT-4H9PHHN-D/2/9985957afc209b56ce827c3be7f2ba56
Petrovic, Radivoj
Senborn, Aleksandar
Vujosevic, Mirko
oai:RePEc:eee:ejores:v:167:y:2005:i:1:p:28-342009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:167:y:2005:i:1:p:28-34
article
Non-differentiable higher-order symmetric duality in mathematical programming with generalized invexity
http://www.sciencedirect.com/science/article/B6VCT-4CN9PTG-1/2/f3d173e6676efdcae3985cfc143bc7a7
Mishra, S. K.
oai:RePEc:eee:ejores:v:183:y:2007:i:3:p:1595-16062009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:183:y:2007:i:3:p:1595-1606
article
Measuring retail company performance using credit scoring techniques
http://www.sciencedirect.com/science/article/B6VCT-4N08MBC-1/2/7b36a3c7b493744d7c71f0997e8575e1
Hu, Yu-Chiang
Ansell, Jake
oai:RePEc:eee:ejores:v:54:y:1991:i:2:p:141-1502009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:54:y:1991:i:2:p:141-150
article
Cutting stock problems and solution procedures
http://www.sciencedirect.com/science/article/B6VCT-48NBG1F-1R7/2/3943a9b57d6d020e88aa9f049293e1a0
Haessler, Robert W.
Sweeney, Paul E.
oai:RePEc:eee:ejores:v:94:y:1996:i:1:p:112-1212009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:94:y:1996:i:1:p:112-121
article
A ratio model for discriminant analysis using linear programming
http://www.sciencedirect.com/science/article/B6VCT-3VV42S8-1F/2/d28a138420a785231e89898a672a57f6
Retzlaff-Roberts, Donna L.
oai:RePEc:eee:ejores:v:88:y:1996:i:2:p:231-2502009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:88:y:1996:i:2:p:231-250
article
Scheduling crackdowns on illicit drug markets
http://www.sciencedirect.com/science/article/B6VCT-3VWPNJF-3/2/55b8c285a6ad2d1b2d59036b3ae6b293
Naik, Ashich V.
Baveja, Alok
Batta, Rajan
Caulkins, Jonathan P.
oai:RePEc:eee:ejores:v:87:y:1995:i:3:p:500-5062009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:87:y:1995:i:3:p:500-506
article
Operational research models in action, the result of international cooperation -- A potpourri
http://www.sciencedirect.com/science/article/B6VCT-40324HT-K/2/3d2e179449344dc3ed5334d8bba3ebfb
Petrovic, Radivoj
Guberinic, Slobodan
Batanovic, Vladan
Cvetkovic, Dragos
oai:RePEc:eee:ejores:v:147:y:2003:i:2:p:373-3962009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:147:y:2003:i:2:p:373-396
article
The two- and m-machine flowshop scheduling problems with bicriteria of makespan and mean flowtime
http://www.sciencedirect.com/science/article/B6VCT-45JYDF7-3/2/bee847440d37015144fbdbe5d0b54c19
Allahverdi, Ali
oai:RePEc:eee:ejores:v:170:y:2006:i:1:p:241-2522009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:170:y:2006:i:1:p:241-252
article
Stochastic multicriteria acceptability analysis using the data envelopment model
http://www.sciencedirect.com/science/article/B6VCT-4DB570S-4/2/e62f5deb838fdb3f676a428394d5fe89
Lahdelma, Risto
Salminen, Pekka
oai:RePEc:eee:ejores:v:198:y:2009:i:1:p:275-2862009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:198:y:2009:i:1:p:275-286
article
Mathematical justification of a heuristic for statistical correlation of real-life time series
Many of the analyses of time series that arise in real-life situations require the adoption of various simplifying assumptions so as to cope with the complexity of the phenomena under consideration. Whilst accepting that these simplifications lead to heuristics providing less accurate processing of information compared to the solution of analytical equations, the intelligent choice of the simplifications coupled with the empirical verification of the resulting heuristic has proven itself to be a powerful systems modelling paradigm. In this study, we look at the theoretical underpinning of a successful heuristic for estimation of urban travel times from lane occupancy measurements. We show that by interpreting time series as statistical processes with a known distribution it is possible to estimate travel time as a limit value of an appropriately defined statistical process. The proof of the theorem asserting the above, supports the conclusion that it is possible to design a heuristic that eliminates the adverse effect of spurious readings without loosing temporal resolution of data (as implied by the standard method of data averaging). The original contribution of the paper concerning the link between the analytical modelling and the design of heuristics is general and relevant to a broad spectrum of applications.
Programming: algorithms, heuristic Statistics: correlation, time series Transportation: models, traffic
http://www.sciencedirect.com/science/article/B6VCT-4T13CJC-4/2/98d40b86d3e29ef1047035955d207523
Agafonov, Evgeny
Bargiela, Andrzej
Burke, Edmund
Peytchev, Evtim
oai:RePEc:eee:ejores:v:190:y:2008:i:3:p:798-8172009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:190:y:2008:i:3:p:798-817
article
Basin-wide cooperative water resources allocation
The Cooperative Water Allocation Model (CWAM) is designed within a general mathematical programming framework for modeling equitable and efficient water allocation among competing users at the basin level and applied to a large-scale water allocation problem in the South Saskatchewan River Basin located in southern Alberta, Canada. This comprehensive model consists of two main steps: initial water rights allocation and subsequent water and net benefits reallocation. Two mathematical programming approaches, called the priority-based maximal multiperiod network flow (PMMNF) method and the lexicographic minimax water shortage ratios (LMWSR) technique, are developed for use in the first step. Cooperative game theoretic approaches are utilized to investigate how the net benefits can be fairly reallocated to achieve optimal economic reallocation of water resources in the second step. The application of this methodology to the South Saskatchewan River Basin shows that CWAM can be utilized as a tool for promoting the understanding and cooperation of water users to achieve maximum welfare in a river basin and minimize the potential damage caused by water shortages, through water rights allocation, and water and net benefit transfers among water users under a regulated water market or administrative allocation mechanism.
http://www.sciencedirect.com/science/article/B6VCT-4P5NX3K-3/1/5633f3b68eb22a7d61bbf759a8f3227e
Wang, Lizhong
Fang, Liping
Hipel, Keith W.
oai:RePEc:eee:ejores:v:73:y:1994:i:3:p:487-4942009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:73:y:1994:i:3:p:487-494
article
Efficiency improvement in data envelopment analysis
http://www.sciencedirect.com/science/article/B6VCT-48NBHC3-262/2/ccc14222456c8729b9f5bb05d898308f
Kao, Chiang
oai:RePEc:eee:ejores:v:83:y:1995:i:1:p:245-2462009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:83:y:1995:i:1:p:245-246
article
A comment on "models, modelling and modellers: an application to risk analysis" by B. Wahlstrom European Journal of Operational Research 75 (1994) 477-487
http://www.sciencedirect.com/science/article/B6VCT-4031R2C-1P/2/118fa9da66a0a6b9d49d461af86a217a
Cooper, W. W.
oai:RePEc:eee:ejores:v:174:y:2006:i:2:p:766-7762009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:174:y:2006:i:2:p:766-776
article
Optimal lot size and inspection policy for products sold with warranty
http://www.sciencedirect.com/science/article/B6VCT-4G65V6S-7/2/9c4e308211045cbf90d43307c7ca086a
Yeh, Ruey Huei
Chen, Tzu-Hui
oai:RePEc:eee:ejores:v:190:y:2008:i:1:p:268-2762009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:190:y:2008:i:1:p:268-276
article
Program portfolio selection for reducing prioritized security risks
The methodology presented here solves an R&D program portfolio selection problem that arises in critical infrastructure protection and similar security risk reduction problems. It requires priorities to be assigned to the risks, existing risk levels to be assessed, and the effectiveness of alternative risk reduction programs to be estimated. A lexicographic optimization procedure involving mixed integer programming with preemptive priorities is developed and illustrated, and extensions are discussed.
http://www.sciencedirect.com/science/article/B6VCT-4NXRMHD-5/1/805bb80af471d7f05e684e5aaee620f3
Glickman, Theodore S.
oai:RePEc:eee:ejores:v:126:y:2000:i:3:p:587-6022009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:126:y:2000:i:3:p:587-602
article
An exponential queue with competition for service
http://www.sciencedirect.com/science/article/B6VCT-4135XF5-C/2/2eaecbf4810abd67c087f41f682f546e
Brill, P. H.
Hlynka, M.
oai:RePEc:eee:ejores:v:176:y:2007:i:1:p:230-2392009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:176:y:2007:i:1:p:230-239
article
Planning annualised hours with a finite set of weekly working hours and cross-trained workers
http://www.sciencedirect.com/science/article/B6VCT-4H8MNWP-4/2/9a20afe9fcc76af8847f8751bd923f31
Corominas, Albert
Lusa, Amaia
Pastor, Rafael
oai:RePEc:eee:ejores:v:107:y:1998:i:2:p:250-2592009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:107:y:1998:i:2:p:250-259
article
The resource constrained project scheduling problem with multiple crashable modes: A heuristic procedure
http://www.sciencedirect.com/science/article/B6VCT-3VGMD1N-2/2/56acb6113c411e7a39a2392391b32deb
Ahn, Taeho
Erenguc, S. Selcuk
oai:RePEc:eee:ejores:v:101:y:1997:i:1:p:74-802009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:101:y:1997:i:1:p:74-80
article
Greedy sets and related problems
http://www.sciencedirect.com/science/article/B6VCT-3SX26WR-7/2/9611d4cacaf7c0056f4b616fa317192d
Girlich, Eberhard
Kovalev, Michail M.
Vasilkov, Dmitri M.
oai:RePEc:eee:ejores:v:34:y:1988:i:3:p:393-3982009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:34:y:1988:i:3:p:393-398
article
A parallel integer linear programming algorithm
http://www.sciencedirect.com/science/article/B6VCT-48M3FK0-2B/2/91bb0c1fcf5dabad36de536cdef8c7b0
Boehning, Rochelle L.
Butler, Ralph M.
Gillett, Billy E.
oai:RePEc:eee:ejores:v:182:y:2007:i:2:p:945-9512009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:182:y:2007:i:2:p:945-951
article
A note on the two-stage assembly flow shop scheduling problem with uniform parallel machines
http://www.sciencedirect.com/science/article/B6VCT-4M7VB41-B/2/8911d15090c6992b1e324c5cbd211eae
Koulamas, Christos
Kyparisis, George J.
oai:RePEc:eee:ejores:v:147:y:2003:i:2:p:405-4172009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:147:y:2003:i:2:p:405-417
article
Uncapacitated point-to-multipoint network flow problem and its application to multicasting in telecommunication networks
http://www.sciencedirect.com/science/article/B6VCT-45M0R5W-3/2/f547eeb3a5a977955fbc5240348978ba
Park, Koohyun
Shin, Yong-Sik
oai:RePEc:eee:ejores:v:184:y:2008:i:2:p:509-5332009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:184:y:2008:i:2:p:509-533
article
A deterministic EOQ model with delays in payments and price-discount offers
http://www.sciencedirect.com/science/article/B6VCT-4MVDVHW-2/2/e56e89580e93050b3f2c78334e521991
Sana, Shib Sankar
Chaudhuri, K.S.
oai:RePEc:eee:ejores:v:172:y:2006:i:2:p:472-4992009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:172:y:2006:i:2:p:472-499
article
A 3-flip neighborhood local search for the set covering problem
http://www.sciencedirect.com/science/article/B6VCT-4F53N82-3/2/81551190f06a3cfda0961640204b7d19
Yagiura, Mutsunori
Kishida, Masahiro
Ibaraki, Toshihide
oai:RePEc:eee:ejores:v:73:y:1994:i:1:p:132-1382009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:73:y:1994:i:1:p:132-138
article
Discharge allocation for hydro-electric generating stations
http://www.sciencedirect.com/science/article/B6VCT-48NBMSJ-3KR/2/f6e22812b371c2594dbce61b4bcae940
Klein, E. M.
Sim, S. H.
oai:RePEc:eee:ejores:v:174:y:2006:i:1:p:480-4912009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:174:y:2006:i:1:p:480-491
article
A simple procedure for determining order quantities under a fill rate constraint and normally distributed lead-time demand
http://www.sciencedirect.com/science/article/B6VCT-4FSCMJ5-7/2/b4d79dbcac0d2e3f5d90cda25c44de6f
Axsater, Sven
oai:RePEc:eee:ejores:v:131:y:2001:i:3:p:622-6342009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:131:y:2001:i:3:p:622-634
article
A performance analysis of dispatching rules and a heuristic in static flowshops with missing operations of jobs
http://www.sciencedirect.com/science/article/B6VCT-42MW5Y7-G/2/48dd963630d066707453cd7115b7a428
Rajendran, Chandrasekharan
Ziegler, Hans
oai:RePEc:eee:ejores:v:196:y:2009:i:2:p:544-5532009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:196:y:2009:i:2:p:544-553
article
Would a risk-averse newsvendor order less at a higher selling price?
We model a risk-averse newsvendor's decision-making behavior with some commonly used classes of utility functions within the expected utility theory (EUT) framework. Under fairly general conditions of EUT, we show that a risk-averse newsvendor will order less than an arbitrarily small quantity as selling price gets larger if price is higher than a threshold value, i.e., the optimal order quantity decreases as the selling price increases.
Expected utility theory Risk aversion Newsvendor model
http://www.sciencedirect.com/science/article/B6VCT-4S7J5FT-1/2/c05d03cd8644e24887fa7b84eba85147
Wang, Charles X.
Webster, Scott
Suresh, Nallan C.
oai:RePEc:eee:ejores:v:83:y:1995:i:3:p:466-4882009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:83:y:1995:i:3:p:466-488
article
Modeling investment uncertainty in the costs of global CO2 emission policy
http://www.sciencedirect.com/science/article/B6VCT-4031R0C-4/2/1e76523205071555b3cb4b4a3f3c4fad
Birge, John R.
Rosa, Charles H.
oai:RePEc:eee:ejores:v:175:y:2006:i:3:p:1833-18492009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:175:y:2006:i:3:p:1833-1849
article
Multi-objective metaheuristics for a location-routing problem with multiple use of vehicles on real data and simulated data
http://www.sciencedirect.com/science/article/B6VCT-4GV8T84-F/2/cd78bdcfaa1ed988b503eb8f1c32677c
Lin, C.K.Y.
Kwok, R.C.W.
oai:RePEc:eee:ejores:v:80:y:1995:i:3:p:691-7022009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:80:y:1995:i:3:p:691-702
article
Measuring technical progress with data envelopment analysis
http://www.sciencedirect.com/science/article/B6VCT-4031TFX-K/2/b3d18bb0763d25c883eba80817c32970
Wei, Q. L.
Sun, Bruce
Xiao, Z. J.
oai:RePEc:eee:ejores:v:52:y:1991:i:3:p:367-3722009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:52:y:1991:i:3:p:367-372
article
Optimal control of a queuing network system with two types of customers
http://www.sciencedirect.com/science/article/B6VCT-48NBBVN-JW/2/caca79c2e2f45213e7018d9d8a68f510
Shioyama, Tadayoshi
oai:RePEc:eee:ejores:v:194:y:2009:i:1:p:114-1262009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:194:y:2009:i:1:p:114-126
article
Quality inspection scheduling for multi-unit service enterprises
The traveling salesman problem is a classic NP-hard problem used to model many production and scheduling problems. The problem becomes even more difficult when additional salesmen are added to create a multiple traveling salesman problem (MTSP). We consider a variation of this problem where one salesman visits a given set of cities in a series of short trips. This variation is faced by numerous franchise companies that use quality control inspectors to ensure properties are maintaining acceptable facility and service levels. We model an actual franchised hotel chain using traveling quality inspectors to demonstrate the technique. The model is solved using a commercially available genetic algorithm (GA) tool as well as a custom GA program. The custom GA is proven to be an effective method of solving the proposed model.
Genetic algorithms Scheduling Traveling salesman
http://www.sciencedirect.com/science/article/B6VCT-4RC2S0C-1/2/fcf0d724a919b4ea27b79adf413763bf
Carter, Arthur E.
Ragsdale, Cliff T.
oai:RePEc:eee:ejores:v:5:y:1980:i:4:p:276-2832009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:5:y:1980:i:4:p:276-283
article
On the blocking process in queue networks
http://www.sciencedirect.com/science/article/B6VCT-48NBDYY-1D9/2/3bf45af19804e51a4a313e64bd25c361
Foster, F. G.
Perros, H. G.
oai:RePEc:eee:ejores:v:104:y:1998:i:2:p:269-2872009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:104:y:1998:i:2:p:269-287
article
Some personal views on the current state and the future of locational analysis
http://www.sciencedirect.com/science/article/B6VCT-3SX6GTB-T/2/bf3804d2db31bb61e1a42fe5da2b14cf
Avella, P.
Benati, S.
Canovas Martinez, L.
Dalby, K.
Di Girolamo, D.
Dimitrijevic, B.
Ghiani, G.
Giannikos, I.
Guttmann, N.
Hultberg, T. H.
Fliege, J.
Marin, A.
Munoz Marquez, M.
Ndiaye, M. M.
Nickel, S.
Peeters, P.
Perez Brito, D.
Policastro, S.
Saldanha de Gama, F. A.
Zidda, P.
oai:RePEc:eee:ejores:v:15:y:1984:i:1:p:126-1302009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:15:y:1984:i:1:p:126-130
article
A branch and bound method for multi-objective boolean problems
http://www.sciencedirect.com/science/article/B6VCT-48VW6YP-1R/2/fbd4b67355ca86f295489ce9d19014a2
White, D. J.
oai:RePEc:eee:ejores:v:87:y:1995:i:1:p:200-2022009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:87:y:1995:i:1:p:200-202
article
QHOPDM -- A higher order primal-dual method for large scale convex quadratic programming
http://www.sciencedirect.com/science/article/B6VCT-40324MR-2D/2/9874d42d4a2528427e299c99f7df2541
Altman, Anna
oai:RePEc:eee:ejores:v:86:y:1995:i:1:p:103-1192009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:86:y:1995:i:1:p:103-119
article
Decentralization of responsibility for site decontamination projects: A budget allocation approach
http://www.sciencedirect.com/science/article/B6VCT-4031T5Y-1C/2/6b94940f95c053e569e5e66765cf67d3
Corbett, Charles J.
Debets, Frank J.C.
Van Wassenhove, Luk N.
oai:RePEc:eee:ejores:v:176:y:2007:i:1:p:347-3602009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:176:y:2007:i:1:p:347-360
article
On a multicommodity stochastic-flow network with unreliable nodes subject to budget constraint
http://www.sciencedirect.com/science/article/B6VCT-4H27C2N-7/2/4ee130b03b38e9db8f326a6aada113e6
Lin, Yi-Kuei
oai:RePEc:eee:ejores:v:180:y:2007:i:2:p:868-8842009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:180:y:2007:i:2:p:868-884
article
Multiple-input dual-output adjustment scheme for semiconductor manufacturing processes using a dynamic dual-response approach
http://www.sciencedirect.com/science/article/B6VCT-4K71680-6/2/eee340e7f70022c59c092bea11589e44
Fan, Shu-Kai S.
Lin, Yen
oai:RePEc:eee:ejores:v:171:y:2006:i:1:p:107-1222009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:171:y:2006:i:1:p:107-122
article
Two machine preemptive scheduling problem with release dates, equal processing times and precedence constraints
http://www.sciencedirect.com/science/article/B6VCT-4DR1SDP-2/2/2e2bd75aa61a12efff36e36168d82340
Lushchakova, Irene N.
oai:RePEc:eee:ejores:v:5:y:1980:i:5:p:289-2912009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:5:y:1980:i:5:p:289-291
article
Foreword: Excerpts from a guest editor's diary
http://www.sciencedirect.com/science/article/B6VCT-48NBJ3M-2HS/2/e0eef9353597e57e30cd2c82440f1621
Krarup, Jakob
oai:RePEc:eee:ejores:v:25:y:1986:i:1:p:50-672009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:25:y:1986:i:1:p:50-67
article
Non-linear dynamical systems theory and locational analysis
http://www.sciencedirect.com/science/article/B6VCT-48MYH25-3X/2/c7e5f892fb4acce29083053a3d2f6a22
Clarke, M.
oai:RePEc:eee:ejores:v:41:y:1989:i:2:p:151-1562009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:41:y:1989:i:2:p:151-156
article
Optimal, near-optimal and rule-of-thumb claiming rules for a protected bonus vehicle insurance policy
http://www.sciencedirect.com/science/article/B6VCT-48NBD3D-10M/2/3bf875b37df62c4d3b449f5220524415
Chappell, D.
Norman, J. M.
oai:RePEc:eee:ejores:v:125:y:2000:i:3:p:633-6472009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:125:y:2000:i:3:p:633-647
article
A decision support system for business process planning
http://www.sciencedirect.com/science/article/B6VCT-40NMSSJ-F/2/78da499a283a45642c33c89ed609f524
Volkner, Peer
Werners, Brigitte
oai:RePEc:eee:ejores:v:58:y:1992:i:1:p:1-22009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:58:y:1992:i:1:p:1-2
article
Warehouse design and operation
http://www.sciencedirect.com/science/article/B6VCT-48NBCPT-TN/2/e15bb69bd4280df3873e560ebce4327c
Gelders, Ludo F.
oai:RePEc:eee:ejores:v:77:y:1994:i:1:p:70-812009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:77:y:1994:i:1:p:70-81
article
Constrained gaming approaches to decisionmaking under uncertainty
http://www.sciencedirect.com/science/article/B6VCT-48NBHG3-27C/2/c2a2edfeb66d795b732ac9d69236ee23
Ryan, Michael J.
oai:RePEc:eee:ejores:v:11:y:1982:i:3:p:285-2942009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:11:y:1982:i:3:p:285-294
article
OR and energy: Problems of modelling
http://www.sciencedirect.com/science/article/B6VCT-48MYHCF-CS/2/447b14eb608912383abc8cbec4e83108
Kavrakoglu, Ibrahim
oai:RePEc:eee:ejores:v:169:y:2006:i:2:p:533-5472009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:169:y:2006:i:2:p:533-547
article
A scatter search heuristic for the capacitated clustering problem
http://www.sciencedirect.com/science/article/B6VCT-4DGYG78-4/2/1bd5bad7345874f41cf78a65901aa2ab
Scheuerer, Stephan
Wendolsky, Rolf
oai:RePEc:eee:ejores:v:99:y:1997:i:2:p:221-2352009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:99:y:1997:i:2:p:221-235
article
Lot sizing and scheduling -- Survey and extensions
http://www.sciencedirect.com/science/article/B6VCT-3SWYB98-V/2/9e6689837477f40188ee0015460197bb
Drexl, A.
Kimms, A.
oai:RePEc:eee:ejores:v:176:y:2007:i:1:p:423-4342009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:176:y:2007:i:1:p:423-434
article
A mixed integer linear programming formulation of the optimal mean/Value-at-Risk portfolio problem
http://www.sciencedirect.com/science/article/B6VCT-4HMFJ96-1/2/31314de75ab1b020e04150f5b8f7598b
Benati, Stefano
Rizzi, Romeo
oai:RePEc:eee:ejores:v:183:y:2007:i:1:p:314-3262009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:183:y:2007:i:1:p:314-326
article
Fuzzy implication operators for difference operations for fuzzy sets and cardinality-based measures of comparison
http://www.sciencedirect.com/science/article/B6VCT-4MJS038-6/2/4a19e546a97ca4b9b1d863ff818dc6c2
Fono, Louis Aime
Gwet, Henri
Bouchon-Meunier, Bernadette
oai:RePEc:eee:ejores:v:44:y:1990:i:2:p:160-1662009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:44:y:1990:i:2:p:160-166
article
Knowledge-based systems for cutting stock problems
http://www.sciencedirect.com/science/article/B6VCT-48MYHSS-F2/2/46abf4071336db98a0d9ac1024ea22e5
H. Dagli, Cihan
oai:RePEc:eee:ejores:v:160:y:2005:i:3:p:851-8762009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:160:y:2005:i:3:p:851-876
article
Search during decision making
http://www.sciencedirect.com/science/article/B6VCT-4B1SMWY-8/2/423287ee7148fe00b83e56f6e6b2b35e
Nutt, Paul C.
oai:RePEc:eee:ejores:v:61:y:1992:i:1-2:p:6-172009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:61:y:1992:i:1-2:p:6-17
article
Rule-based simulation metamodels
http://www.sciencedirect.com/science/article/B6VCT-48MYGP3-34/2/f43141de4e7ba467108ffbdbca1f149f
Pierreval, Henri
oai:RePEc:eee:ejores:v:96:y:1997:i:1:p:54-632009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:96:y:1997:i:1:p:54-63
article
Optimal lines for railway systems
http://www.sciencedirect.com/science/article/B6VCT-3T7HK9P-W/2/af7067b59dcf04e15dd21eac56acca39
Bussieck, Michael R.
Kreuzer, Peter
Zimmermann, Uwe T.
oai:RePEc:eee:ejores:v:117:y:1999:i:1:p:125-1352009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:117:y:1999:i:1:p:125-135
article
Approximation methods for non-convex curves
http://www.sciencedirect.com/science/article/B6VCT-3WG322V-9/2/5166fd8d8ed98e2e26680fba53b5e064
Liu, Y.
Teo, K. L.
Yang, X. Q.
oai:RePEc:eee:ejores:v:10:y:1982:i:3:p:294-3012009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:10:y:1982:i:3:p:294-301
article
Fuzzy clustering algorithms and their cluster validity
http://www.sciencedirect.com/science/article/B6VCT-48NBK6T-2Y7/2/875b6e7cde55a6610631e0a7660a76cf
Roubens, Marc
oai:RePEc:eee:ejores:v:187:y:2008:i:3:p:1504-15122009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:187:y:2008:i:3:p:1504-1512
article
Production planning problem with sequence dependent setups as a bilevel programming problem
http://www.sciencedirect.com/science/article/B6VCT-4MM8BF6-2/2/0fb630ab67978862fca2f2622b00660f
Lukac, Zrinka
Soric, Kristina
Rosenzweig, Visnja Vojvodic
oai:RePEc:eee:ejores:v:160:y:2005:i:1:p:232-2412009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:160:y:2005:i:1:p:232-241
article
Multiparametric sensitivity analysis in programming problem with linear-plus-linear fractional objective function
http://www.sciencedirect.com/science/article/B6VCT-4B0X73J-4/2/2296e8b02d91115eaf8eb6e5d1791057
Singh, Sanjeet
Gupta, Pankaj
Bhatia, Davinder
oai:RePEc:eee:ejores:v:89:y:1996:i:1:p:108-1262009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:89:y:1996:i:1:p:108-126
article
A heuristic algorithm for the asymmetric capacitated vehicle routing problem
http://www.sciencedirect.com/science/article/B6VCT-4B0NB5J-C/2/f212e82c60daace16165f3ceb38d9376
Vigo, Daniele
oai:RePEc:eee:ejores:v:103:y:1997:i:3:p:557-5722009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:103:y:1997:i:3:p:557-572
article
Reordering strategies for a newsboy-type product
http://www.sciencedirect.com/science/article/B6VCT-3SX4N53-22/2/11fbe28b467a47c19239a9737284fa7e
Lau, Hon-Shiang
Lau, Amy Hing-Ling
oai:RePEc:eee:ejores:v:136:y:2002:i:3:p:603-6152009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:136:y:2002:i:3:p:603-615
article
A comparative study of the effect of the position of outliers on classical and nontraditional approaches to the two-group classification problem
http://www.sciencedirect.com/science/article/B6VCT-44HXKGS-B/2/3786a4b40cf706268c7bbe3c72c2c549
Pavur, Robert
oai:RePEc:eee:ejores:v:109:y:1998:i:1:p:228-2412009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:109:y:1998:i:1:p:228-241
article
Comments on: A comparative analysis for determining optimal price and order quantity when a sale increases demand
http://www.sciencedirect.com/science/article/B6VCT-3TMR6M6-J/2/c398f7f420828e41e0dd08993ee4048c
Joglekar, Prafulla
Lee, Patrick
oai:RePEc:eee:ejores:v:149:y:2003:i:1:p:77-1012009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:149:y:2003:i:1:p:77-101
article
A genetic-based framework for solving (multi-criteria) weighted matching problems
http://www.sciencedirect.com/science/article/B6VCT-47P1V7K-5/2/93481e5d5c42058158cf50a98968b95f
Medaglia, Andres L.
Fang, Shu-Cherng
oai:RePEc:eee:ejores:v:183:y:2007:i:2:p:812-8262009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:183:y:2007:i:2:p:812-826
article
Matching daily healthcare provider capacity to demand in advanced access scheduling systems
http://www.sciencedirect.com/science/article/B6VCT-4NB2SHY-1/2/38e89b7e27abb45a09d331ad4afe1ccf
Qu, Xiuli
Rardin, Ronald L.
Williams, Julie Ann S.
Willis, Deanna R.
oai:RePEc:eee:ejores:v:161:y:2005:i:2:p:377-3852009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:161:y:2005:i:2:p:377-385
article
On the comparison between the APV and the NPV computed via the WACC
http://www.sciencedirect.com/science/article/B6VCT-4B5BDF3-3/2/69750d239ac461dcbf2db48231b9db8b
Cigola, Margherita
Peccati, Lorenzo
oai:RePEc:eee:ejores:v:125:y:2000:i:3:p:535-5502009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:125:y:2000:i:3:p:535-550
article
Sequencing of jobs in some production system
http://www.sciencedirect.com/science/article/B6VCT-40NMSSJ-7/2/b927711d0953ded627f1be4196a12932
Grabowski, Jozef
Pempera, Jaroslaw
oai:RePEc:eee:ejores:v:161:y:2005:i:2:p:416-4312009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:161:y:2005:i:2:p:416-431
article
The impacts of regulated notions of quality on farm efficiency: A DEA application
http://www.sciencedirect.com/science/article/B6VCT-4B724RV-2/2/1ab454fd3eef22f1e0c5cd7c2d67f529
Dimara, Efthalia
Pantzios, Christos J.
Skuras, Dimitris
Tsekouras, Kostas
oai:RePEc:eee:ejores:v:68:y:1993:i:3:p:352-3552009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:68:y:1993:i:3:p:352-355
article
A restricted class of multiobjective linear fractional programming problems
http://www.sciencedirect.com/science/article/B6VCT-48VW7J9-B3/2/719ec2cb9e2c74190511563c87a35c2c
Dutta, D.
Rao, J. R.
Tiwari, R. N.
oai:RePEc:eee:ejores:v:9:y:1982:i:4:p:327-3382009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:9:y:1982:i:4:p:327-338
article
"The island": Developing a controlled game for teaching and research
http://www.sciencedirect.com/science/article/B6VCT-48NBK3P-2WC/2/1ee3ae70eff19f9c246cdcf1acc7912a
Bennett, P. G.
Newmark, R. P.
oai:RePEc:eee:ejores:v:19:y:1985:i:2:p:176-1852009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:19:y:1985:i:2:p:176-185
article
Social indicators and policy selection: An experiment in constructing a social objective function
http://www.sciencedirect.com/science/article/B6VCT-48NBKHD-332/2/d8a8565648a2f86543358361c642d14c
Howard, K.
Sharp, J. A.
oai:RePEc:eee:ejores:v:130:y:2001:i:1:p:111-1202009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:130:y:2001:i:1:p:111-120
article
Redistribution of funds for teaching and research among universities: The case of North Rhine-Westphalia
http://www.sciencedirect.com/science/article/B6VCT-426XWHV-9/2/c548d1fdced883a9bdd5e2030468e414
Fandel, Gunter
Gal, Tomas
oai:RePEc:eee:ejores:v:141:y:2002:i:2:p:393-4092009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:141:y:2002:i:2:p:393-409
article
Solving container loading problems by block arrangement
http://www.sciencedirect.com/science/article/B6VCT-45CDH9J-5/2/5e1a8f845c77892d5c05da913ef3dae7
Eley, Michael
oai:RePEc:eee:ejores:v:15:y:1984:i:3:p:310-3192009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:15:y:1984:i:3:p:310-319
article
Initial supply and re-order level of new service parts
http://www.sciencedirect.com/science/article/B6VCT-48NBGD8-1VM/2/6a840ab1402318eaf9d47bb94033184b
Fortuin, Leonard
oai:RePEc:eee:ejores:v:32:y:1987:i:2:p:251-2592009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:32:y:1987:i:2:p:251-259
article
Optimal search for one of many objects hidden in two boxes
http://www.sciencedirect.com/science/article/B6VCT-4GJVBRY-9/2/bd42dc529a07751205a952e1e7028aa7
Sharlin, Ariela
oai:RePEc:eee:ejores:v:146:y:2003:i:3:p:433-4432009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:146:y:2003:i:3:p:433-443
article
Sensitivity analysis by experimental design and metamodelling: Case study on simulation in national animal disease control
http://www.sciencedirect.com/science/article/B6VCT-45JPHMP-5/2/62c61edd1b0f5ac6d9c61e05d6709d1e
Vonk Noordegraaf, Antonie
Nielen, Mirjam
Kleijnen, Jack P. C.
oai:RePEc:eee:ejores:v:172:y:2006:i:1:p:127-1452009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:172:y:2006:i:1:p:127-145
article
Sequential variable sampling plan for normal distribution
http://www.sciencedirect.com/science/article/B6VCT-4DWH3TT-3/2/c11a0b7c561543b541b87d5c41a4db15
Lam, Yeh
Li, Kim-Hung
Ip, Wai-Cheung
Wong, Heung
oai:RePEc:eee:ejores:v:62:y:1992:i:3:p:294-3012009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:62:y:1992:i:3:p:294-301
article
Fuzzy job sequencing for a flow shop
http://www.sciencedirect.com/science/article/B6VCT-48NBC33-MS/2/31dc49ac97a972f27a66808fb6504fbc
McCahon, Cynthia S.
Lee, E. Stanley
oai:RePEc:eee:ejores:v:88:y:1996:i:2:p:251-2562009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:88:y:1996:i:2:p:251-256
article
Economical and ecological utility oriented analysis of the process of anaerobic digestion of waste waters
http://www.sciencedirect.com/science/article/B6VCT-3VWPNJF-4/2/add09d02cdbc8d1c500665d000d6e973
Pavlov, Yu.
Grancharov, D.
Momchev, V.
oai:RePEc:eee:ejores:v:100:y:1997:i:3:p:638-6412009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:100:y:1997:i:3:p:638-641
article
A response to "A comment on 'Grey integer programming: An application to waste management planning under uncertainty"' by Larry Jenkins
http://www.sciencedirect.com/science/article/B6VCT-3SX0PMB-S/2/7f07576a2b256897de6cda414c0cba83
Huang, G. H.
Baetz, B. W.
Patry, G. G.
oai:RePEc:eee:ejores:v:139:y:2002:i:3:p:521-5322009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:139:y:2002:i:3:p:521-532
article
Districting for salt spreading operations
http://www.sciencedirect.com/science/article/B6VCT-45DBB6C-5/2/316f8ff915f6307cb108a39ad54f5327
Muyldermans, L.
Cattrysse, D.
Van Oudheusden, D.
Lotan, T.
oai:RePEc:eee:ejores:v:183:y:2007:i:1:p:460-4712009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:183:y:2007:i:1:p:460-471
article
Planning and approximation models for delivery route based services with price-sensitive demands
http://www.sciencedirect.com/science/article/B6VCT-4M7CDFJ-3/2/37508572dde4b0f59294fe018baba5ff
Geunes, Joseph
Shen, Zuo-Jun Max
Emir, Akin
oai:RePEc:eee:ejores:v:97:y:1997:i:1:p:87-932009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:97:y:1997:i:1:p:87-93
article
Weber problems with alternative transportation systems
http://www.sciencedirect.com/science/article/B6VCT-49V617R-B/2/aed73e0a60fe69e1785c3472935c3fd9
Carrizosa, Emilio
Rodriguez-Chia, Antonio M.
oai:RePEc:eee:ejores:v:96:y:1997:i:1:p:1-352009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:96:y:1997:i:1:p:1-35
article
Survey of mathematical programming models in air pollution management
http://www.sciencedirect.com/science/article/B6VCT-3T7HK9P-S/2/0fa7f05c3465072924a31ff317688339
Cooper, W. W.
Hemphill, H.
Huang, Z.
Li, S.
Lelas, V.
Sullivan, D. W.
oai:RePEc:eee:ejores:v:74:y:1994:i:2:p:230-2422009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:74:y:1994:i:2:p:230-242
article
Distributional analysis to model atypical behavior
http://www.sciencedirect.com/science/article/B6VCT-48MYH1K-70/2/a1f0c169d72a5095a2886c5fac2cd768
Baestaens, Dirk-Emma
oai:RePEc:eee:ejores:v:174:y:2006:i:3:p:1540-15522009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:174:y:2006:i:3:p:1540-1552
article
A class of node based bottleneck improvement problems
http://www.sciencedirect.com/science/article/B6VCT-4G65V6S-C/2/de9ed52766103b859b469372c560b668
Guan, Xiucui
Zhang, Jianzhong
oai:RePEc:eee:ejores:v:134:y:2001:i:1:p:84-1022009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:134:y:2001:i:1:p:84-102
article
Using investment portfolio return to combine forecasts: A multiobjective approach
http://www.sciencedirect.com/science/article/B6VCT-43F8D84-7/2/210345402a5dc6a07ad01ce6287e5547
Leung, Mark T.
Daouk, Hazem
Chen, An-Sing
oai:RePEc:eee:ejores:v:15:y:1984:i:2:p:160-1682009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:15:y:1984:i:2:p:160-168
article
The computer as an aid to physical distribution management
http://www.sciencedirect.com/science/article/B6VCT-48NBH2W-22R/2/7b545db558b43f3d7e6966f5a6e140db
Dowsland, William B.
oai:RePEc:eee:ejores:v:19:y:1985:i:2:p:151-1622009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:19:y:1985:i:2:p:151-162
article
An introduction to timetabling
http://www.sciencedirect.com/science/article/B6VCT-48NBKHD-32Y/2/87ecd333ea5bd503f592389b1ad7218e
de Werra, D.
oai:RePEc:eee:ejores:v:98:y:1997:i:3:p:445-4562009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:98:y:1997:i:3:p:445-456
article
Locational optimization problems solved through Voronoi diagrams
http://www.sciencedirect.com/science/article/B6VCT-3SWY0P1-1/2/ff13712d35cd5dcd52e41dfa24013fb5
Okabe, Atsuyuki
Suzuki, Atsuo
oai:RePEc:eee:ejores:v:197:y:2009:i:2:p:572-5802009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:197:y:2009:i:2:p:572-580
article
Exact analysis of a two-workstation one-buffer flow line with parallel unreliable machines
This paper examines a model of a serial flow line with two workstations and an intermediate buffer. Each workstation consists of multiple unreliable parallel machines which are not necessarily identical, viz., the processing times, failure times and repair times of the parallel machines at each workstation are assumed to be exponentially distributed with non-identical mean rates. The system under consideration is solved via exact Markovian analysis. More specifically, a recursive algorithm that generates the transition matrix for any value of the intermediate buffer capacity is developed and all possible transition equations are derived and solved analytically. Once the transition equations are solved the performance measures of the model under consideration can be easily evaluated. This model may be used as a decomposition block for solving larger flow lines with parallel unreliable machines at each workstation.
Flow/production lines Unreliable parallel-machine workstations Performance evaluation Markovian analysis
http://www.sciencedirect.com/science/article/B6VCT-4T0FF5N-4/2/1dd3a69345700bbf2524ac60290a0203
Alexandros, Diamantidis C.
Chrissoleon, Papadopoulos T.
oai:RePEc:eee:ejores:v:174:y:2006:i:3:p:1979-19902009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:174:y:2006:i:3:p:1979-1990
article
Short-term booking of air cargo space
http://www.sciencedirect.com/science/article/B6VCT-4GSJXHP-3/2/f357996d739c2d71eb4b0e74b9947ebb
Chew, Ek-Peng
Huang, Huei-Chuen
Johnson, Ellis L.
Nemhauser, George L.
Sokol, Joel S.
Leong, Chun-How
oai:RePEc:eee:ejores:v:22:y:1985:i:3:p:329-3372009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:22:y:1985:i:3:p:329-337
article
The fleet size and mix problem for capacitated arc routing
http://www.sciencedirect.com/science/article/B6VCT-48NBM4F-3BW/2/c6ec25efaaf09e0addc728104a23551f
Ulusoy, Gunduz
oai:RePEc:eee:ejores:v:154:y:2004:i:2:p:447-4642009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:154:y:2004:i:2:p:447-464
article
Dominance-based measurement of productive and environmental performance for manufacturing
http://www.sciencedirect.com/science/article/B6VCT-48WPTH6-2/2/3205faf044268d42413d1ffbb8c14437
Triantis, Konstantinos
Otis, Paul
oai:RePEc:eee:ejores:v:181:y:2007:i:3:p:1148-11652009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:181:y:2007:i:3:p:1148-1165
article
Modeling gene regulatory networks with piecewise linear differential equations
http://www.sciencedirect.com/science/article/B6VCT-4JT3S34-2/2/84c1d3828bd2844697421bdbd4b59063
Gebert, J.
Radde, N.
Weber, G.-W.
oai:RePEc:eee:ejores:v:91:y:1996:i:2:p:395-4102009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:91:y:1996:i:2:p:395-410
article
A heuristic approach for capacity expansion of packet networks
http://www.sciencedirect.com/science/article/B6VCT-3VW1SSD-K/2/cdda38e04047beca58fff297a439d49c
Dutta, Amitava
Ki Kim, Young
oai:RePEc:eee:ejores:v:162:y:2005:i:3:p:786-7912009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:162:y:2005:i:3:p:786-791
article
On multi-item inventory
http://www.sciencedirect.com/science/article/B6VCT-4BDC9C6-1/2/c8f8e6ca9d3710da506f567400d2b531
Bhattacharya, D. K.
oai:RePEc:eee:ejores:v:147:y:2003:i:3:p:558-5662009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:147:y:2003:i:3:p:558-566
article
The single-item lot-sizing problem with immediate lost sales
http://www.sciencedirect.com/science/article/B6VCT-45XT70X-1/2/b71f20d1341afb5d0f537e0d3f37c91c
Aksen, Deniz
Altinkemer, Kemal
Chand, Suresh
oai:RePEc:eee:ejores:v:152:y:2004:i:1:p:296-2992009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:152:y:2004:i:1:p:296-299
article
A note on `bilevel linear fractional programming problem'
http://www.sciencedirect.com/science/article/B6VCT-47NF754-3/2/101c32570cdfd9dcba859fc49837483e
Calvete, Herminia I.
Gale, Carmen
oai:RePEc:eee:ejores:v:152:y:2004:i:2:p:365-3812009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:152:y:2004:i:2:p:365-381
article
Dispatching of small containers via coastal freight liners: The case of the Aegean Sea
http://www.sciencedirect.com/science/article/B6VCT-49JVJKV-2/2/7a0d811621e7b045f02d0d60b5ddba6e
Sambracos, E.
Paravantis, J. A.
Tarantilis, C. D.
Kiranoudis, C. T.
oai:RePEc:eee:ejores:v:19:y:1985:i:1:p:118-1242009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:19:y:1985:i:1:p:118-124
article
The stochastic linear continuous type knapsack problem: A generalized P model
http://www.sciencedirect.com/science/article/B6VCT-48NBKFB-32G/2/76900cf2bee40cd46c8d321595f70125
Ishii, Hiroaki
Nishida, Toshio
oai:RePEc:eee:ejores:v:7:y:1981:i:2:p:101-1102009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:7:y:1981:i:2:p:101-110
article
Production planning: a review
http://www.sciencedirect.com/science/article/B6VCT-48MYH9J-BD/2/4597182cc7bba597592dc65104ecfacf
Gelders, Ludo F.
Van Wassenhove, Luk N.
oai:RePEc:eee:ejores:v:149:y:2003:i:3:p:614-6242009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:149:y:2003:i:3:p:614-624
article
Three-triplet np control charts
http://www.sciencedirect.com/science/article/B6VCT-47K2XSW-8/2/222079d1b882a29e85d9fc63a52a93d5
Wu, Zhang
Luo, Hua
oai:RePEc:eee:ejores:v:13:y:1983:i:2:p:142-1452009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:13:y:1983:i:2:p:142-145
article
On the service system MX/G/[infinity]
http://www.sciencedirect.com/science/article/B6VCT-49V73TM-4/2/37a3152384a528e7a8c6d58982ccfb8f
Holman, D. F.
Chaudhry, M. L.
Kashyap, B. R. K.
oai:RePEc:eee:ejores:v:57:y:1992:i:1:p:54-702009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:57:y:1992:i:1:p:54-70
article
A distribution multi-echelon lot-size model
http://www.sciencedirect.com/science/article/B6VCT-48NBG4K-1SB/2/fec450351a7f2b4797cd55b87223c3d5
Friedman, Moshe F.
oai:RePEc:eee:ejores:v:9:y:1982:i:2:p:105-1132009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:9:y:1982:i:2:p:105-113
article
Planning and control in insurance
http://www.sciencedirect.com/science/article/B6VCT-48NBK1F-2V5/2/451521b2efc748075f0435228cd82fc5
van Gelder, Hans
oai:RePEc:eee:ejores:v:112:y:1999:i:1:p:107-1212009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:112:y:1999:i:1:p:107-121
article
An approximation for computing the throughput of closed assembly-type queueing networks
http://www.sciencedirect.com/science/article/B6VCT-3YSXJP1-W/2/063a14d9bf654670a80fb18c18e9f01f
Ayhan, Hayriye
Wortman, Martin A.
oai:RePEc:eee:ejores:v:158:y:2004:i:3:p:570-5762009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:158:y:2004:i:3:p:570-576
article
The computational complexity of the relative robust shortest path problem with interval data
http://www.sciencedirect.com/science/article/B6VCT-498TY6T-D/2/99ef704436555ab97ad9a238123f3c64
Zielinski, Pawel
oai:RePEc:eee:ejores:v:55:y:1991:i:1:p:115-1192009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:55:y:1991:i:1:p:115-119
article
QAPLIB-A quadratic assignment problem library
http://www.sciencedirect.com/science/article/B6VCT-48VW7HG-9V/2/674bffe8001abc2a5a7d42d108160e6a
Burkard, R. E.
Karisch, S.
Rendl, F.
oai:RePEc:eee:ejores:v:6:y:1981:i:2:p:162-1652009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:6:y:1981:i:2:p:162-165
article
A graph theoretical bound for the p-median problem
http://www.sciencedirect.com/science/article/B6VCT-48VW7RK-F5/2/6bca1d56e2cf3898e47ed66a868886ad
Galvao, Roberto D.
oai:RePEc:eee:ejores:v:88:y:1996:i:1:p:3-122009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:88:y:1996:i:1:p:3-12
article
Stochastic vehicle routing
http://www.sciencedirect.com/science/article/B6VCT-3VWPNM7-M/2/468bc7cfe7fd2880a0a0f18739957482
Gendreau, Michel
Laporte, Gilbert
Seguin, Rene
oai:RePEc:eee:ejores:v:72:y:1994:i:2:p:376-3862009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:72:y:1994:i:2:p:376-386
article
The relaxation time heuristic for the initial transient problem in M/M/k queueing systems
http://www.sciencedirect.com/science/article/B6VCT-48M34DW-10/2/e5c71d14af5ea0ec5abc5710fa5b9a33
Roth, Emily
oai:RePEc:eee:ejores:v:142:y:2002:i:1:p:81-1072009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:142:y:2002:i:1:p:81-107
article
Improving supply-chain performance by sharing advance demand information
http://www.sciencedirect.com/science/article/B6VCT-468D751-2/2/b5e54bbf9d772d2eac3d22932273a2e1
Thonemann, U. W.
oai:RePEc:eee:ejores:v:119:y:1999:i:3:p:678-6912009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:119:y:1999:i:3:p:678-691
article
On the balancedness of multiple machine sequencing games
http://www.sciencedirect.com/science/article/B6VCT-3XK6T2T-9/2/9150bed2bc70b2465d4189c7ae55c587
Hamers, Herbert
Klijn, Flip
Suijs, Jeroen
oai:RePEc:eee:ejores:v:74:y:1994:i:2:p:198-2292009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:74:y:1994:i:2:p:198-229
article
World wide security market regularities
http://www.sciencedirect.com/science/article/B6VCT-48MYH1K-6Y/2/f31c525ac0da2c641679c10e7392699a
Ziemba, William T.
oai:RePEc:eee:ejores:v:39:y:1989:i:1:p:32-392009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:39:y:1989:i:1:p:32-39
article
The efficiency of uni-directionally patrolled machines with two robot repairmen
http://www.sciencedirect.com/science/article/B6VCT-48NBB14-8J/2/268718e3297879da3d714362f498c6c4
Bunday, Brian D.
Khorram, Esmaile
oai:RePEc:eee:ejores:v:101:y:1997:i:3:p:577-5872009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:101:y:1997:i:3:p:577-587
article
Using an interior point method for the master problem in a decomposition approach
http://www.sciencedirect.com/science/article/B6VCT-3SX26WR-18/2/590da89dcc7b419e2254fc7c0865f62e
Gondzio, J.
Sarkissian, R.
Vial, J.-P.
oai:RePEc:eee:ejores:v:125:y:2000:i:1:p:184-1942009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:125:y:2000:i:1:p:184-194
article
An organizational change perspective on the value of modeling
http://www.sciencedirect.com/science/article/B6VCT-40D60VD-F/2/02cc93f0e3f8d5ca3999f8e2c42ca76f
Liberatore, Matthew J.
Hatchuel, Armand
Weil, Benoit
Stylianou, Antonis C.
oai:RePEc:eee:ejores:v:115:y:1999:i:2:p:254-2692009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:115:y:1999:i:2:p:254-269
article
An integrated inventory-transportation system with modified periodic policy for multiple products
http://www.sciencedirect.com/science/article/B6VCT-3YYT6RC-4/2/bf776b98a4f45922bde34219e379c40d
Qu, Wendy W.
Bookbinder, James H.
Iyogun, Paul
oai:RePEc:eee:ejores:v:122:y:2000:i:3:p:561-5692009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:122:y:2000:i:3:p:561-569
article
Upper and lower bounding procedures for minimum rooted k-subtree problem
http://www.sciencedirect.com/science/article/B6VCT-3YMFK9F-3/2/220ae354c26596debc59ec0a3f44a8d6
Kataoka, Seiji
Araki, Norio
Yamada, Takeo
oai:RePEc:eee:ejores:v:175:y:2006:i:2:p:1021-10322009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:175:y:2006:i:2:p:1021-1032
article
Quality improvement and goodwill accumulation in a dynamic duopoly
http://www.sciencedirect.com/science/article/B6VCT-4H0S1DY-3/2/c5b36f3f9844504a9095e9ed735bca49
El Ouardighi, Fouad
Pasin, Federico
oai:RePEc:eee:ejores:v:187:y:2008:i:3:p:1422-14282009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:187:y:2008:i:3:p:1422-1428
article
A critical analysis of the eigenvalue method used to derive priorities in AHP
http://www.sciencedirect.com/science/article/B6VCT-4MR1P4M-1/2/611c86133191566d9b4299b4a5494723
Bana e Costa, Carlos A.
Vansnick, Jean-Claude
oai:RePEc:eee:ejores:v:156:y:2004:i:3:p:782-7982009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:156:y:2004:i:3:p:782-798
article
A state-transition simulation model for the spread of Salmonella in the pork supply chain
http://www.sciencedirect.com/science/article/B6VCT-48KFHS9-1/2/19cb219f526efeb4967c0392930f5e82
van der Gaag, Monique A.
Vos, Fred
Saatkamp, Helmut W.
van Boven, Michiel
van Beek, Paul
Huirne, Ruud B. M.
oai:RePEc:eee:ejores:v:107:y:1998:i:2:p:431-4502009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:107:y:1998:i:2:p:431-450
article
Multi-mode resource-constrained project scheduling by a simple, general and powerful sequencing algorithm
http://www.sciencedirect.com/science/article/B6VCT-3VGMD1N-J/2/82c67e20c5abbf8c71d27647a81af467
Sprecher, Arno
Drexl, Andreas
oai:RePEc:eee:ejores:v:16:y:1984:i:2:p:152-1562009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:16:y:1984:i:2:p:152-156
article
Media selection by mean-variance analysis
http://www.sciencedirect.com/science/article/B6VCT-48NBH4D-23K/2/36de594ded29ba90390a240447152f29
de Kluyver, C. A.
Baird, F. T.
oai:RePEc:eee:ejores:v:191:y:2008:i:2:p:517-5292009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:191:y:2008:i:2:p:517-529
article
Capability adjustment for gamma processes with mean shift consideration in implementing Six Sigma program
In the 1980s, Motorola, Inc. introduced its Six Sigma quality program to the world. Some quality practitioners questioned why the Six Sigma advocates claim it is necessary to add a 1.5[sigma] shift to the process mean when estimating process capability. Bothe [Bothe, D.R., 2002. Statistical reason for the 1.5[sigma] shift. Quality Engineering 14 (3), 479-487] provided a statistical reason for considering such a shift in the process mean for normal processes. In this paper, we consider gamma processes which cover a wide class of applications. For fixed sample size n, the detection power of the control chart can be computed. For small process mean shifts, it is beyond the control chart detection power, which results in overestimating process capability. To resolve the problem, we first examine Bothe's approach and find the detection power is less than 0.5 when data comes from gamma distribution, showing that Bothe's adjustments are inadequate when we have gamma processes. We then calculate adjustments under various sample sizes n and gamma parameter N, with power fixed to 0.5. At the end, we adjust the formula of process capability to accommodate those shifts which can not be detected. Consequently, our adjustments provide much more accurate capability calculation for gamma processes. For illustration purpose, an application example is presented.
http://www.sciencedirect.com/science/article/B6VCT-4P8GWX6-1/1/d5a95b336f33b83af2b76be0db8c7531
Hsu, Ya-Chen
Pearn, W.L.
Wu, Pei-Ching
oai:RePEc:eee:ejores:v:196:y:2009:i:1:p:78-922009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:196:y:2009:i:1:p:78-92
article
Using a family of critical ratio-based approaches to minimize the number of tardy jobs in the job shop with sequence dependent setup times
This paper addresses the job shop scheduling problem to minimize the number of tardy jobs, considering the sequence dependent setup time. This problem is taken as a sequencing problem, and a family of approaches with different levels of intricacy is proposed. The simplest form is a critical ratio-based dispatching rule, which leads to satisfactory solutions by taking into account the group information rather than only the individual information of jobs. Then, an enhanced approach consisting of an iterative schedule refining mechanism will be given. Its feature is to iteratively adjust the estimation of the remaining processing times of jobs in a dynamic and operation-specific manner. Finally, a genetic algorithm which takes the dispatching rule and the refining mechanism as the core is proposed. The performance of these approaches is carefully examined by a comprehensive experimental study.
Scheduling Job shop Sequence dependent setup Dispatching rules Genetic algorithms
http://www.sciencedirect.com/science/article/B6VCT-4RX072H-6/2/20d076279e59a19acca1867099063162
Chiang, Tsung-Che
Fu, Li-Chen
oai:RePEc:eee:ejores:v:93:y:1996:i:3:p:476-4892009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:93:y:1996:i:3:p:476-489
article
Optimal strategies for general price-quality decision models of new products with learning production costs
http://www.sciencedirect.com/science/article/B6VCT-3VV42PR-N/2/c48f3e4e015a73044053d7d2270e401b
Teng, Jinn-Tsair
Thompson, Gerald L.
oai:RePEc:eee:ejores:v:112:y:1999:i:2:p:249-2572009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:112:y:1999:i:2:p:249-257
article
Multicriterion decision making in river basin planning and development
http://www.sciencedirect.com/science/article/B6VCT-3VGS4B7-1/2/8beb77b64192c78939ab970a37a596c6
Raju, Komaragiri Srinivasa
Pillai, C. R. S.
oai:RePEc:eee:ejores:v:97:y:1997:i:3:p:509-5422009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:97:y:1997:i:3:p:509-542
article
Computational investigations of maximum flow algorithms
http://www.sciencedirect.com/science/article/B6VCT-3SWXMSD-8/2/8d88b6f35cdd701679f1f5b9a328cdbc
Ahuja, Ravindra K.
Kodialam, Murali
Mishra, Ajay K.
Orlin, James B.
oai:RePEc:eee:ejores:v:114:y:1999:i:1:p:15-282009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:114:y:1999:i:1:p:15-28
article
Multiple level production planning in rolling horizon assembly environments
http://www.sciencedirect.com/science/article/B6VCT-3W3DFHB-2/2/b8038fc4229ebbf23a91d91bda5a49a2
Simpson, N. C.
oai:RePEc:eee:ejores:v:191:y:2008:i:2:p:485-5032009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:191:y:2008:i:2:p:485-503
article
Single-vendor multi-buyer inventory coordination under private information
This paper considers the problem of coordinating a single-vendor multi-buyer inventory system when there are privacy restrictions in the information required to solve the problem. The objective function and cost parameters of each facility are regarded as private information that no other facilities in the system have access to. Moreover, each facility is responsible to specify its own replenishment policy. The objective is to minimize the total average setup/ordering and inventory-related cost. Solution methodologies under private and global information are developed to find two types of nested power-of-two stationary policies. The first policy assumes all the buyers must replenish simultaneously. The second policy is a more general case where the common replenishment assumption is relaxed. A simple form of information exchange is uncovered that allows the solution methodologies for private and global information yield the same results. The experimental results suggest that the performance of the proposed heuristics is comparable or better than an existing method.
http://www.sciencedirect.com/science/article/B6VCT-4P5NX3K-4/1/3fb65d0470f820e844867da432b2192b
Chu, Chi-Leung
Leon, V. Jorge
oai:RePEc:eee:ejores:v:30:y:1987:i:2:p:179-1922009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:30:y:1987:i:2:p:179-192
article
Problems in the modelling of socio-cultural systems
http://www.sciencedirect.com/science/article/B6VCT-48MYHC3-85/2/75dca798b1a4e99a8ca07d6eddca4f03
Renfrew, A. Colin
oai:RePEc:eee:ejores:v:187:y:2008:i:3:p:985-10322009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:187:y:2008:i:3:p:985-1032
article
A survey of scheduling problems with setup times or costs
http://www.sciencedirect.com/science/article/B6VCT-4MBBYT9-9/2/1234fe3cd53aa7985be808af7cfe7893
Allahverdi, Ali
Ng, C.T.
Cheng, T.C.E.
Kovalyov, Mikhail Y.
oai:RePEc:eee:ejores:v:23:y:1986:i:3:p:356-3662009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:23:y:1986:i:3:p:356-366
article
Representing inverses in pure network flow optimization
http://www.sciencedirect.com/science/article/B6VCT-4B4RSXS-28/2/a6f539044a7f67c3118cb21628c7d892
Rosenthal, Richard E.
oai:RePEc:eee:ejores:v:106:y:1998:i:1:p:191-1972009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:106:y:1998:i:1:p:191-197
article
Goal network programs: A specialized algorithm and an application
http://www.sciencedirect.com/science/article/B6VCT-3SX82DN-1P/2/4a0b5877aec0fae085abac4cd01ce449
Ali, Agha Iqbal
blanco, Tom
Buclatin, Ben
oai:RePEc:eee:ejores:v:177:y:2007:i:1:p:638-6452009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:177:y:2007:i:1:p:638-645
article
Single machine scheduling problems with controllable processing times and total absolute differences penalties
http://www.sciencedirect.com/science/article/B6VCT-4J616DK-3/2/b8caa228d1d1f9af42e72de72a4f13f5
Wang, Ji-Bo
Xia, Zun-Quan
oai:RePEc:eee:ejores:v:151:y:2003:i:3:p:520-5352009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:151:y:2003:i:3:p:520-535
article
New savings based algorithms for time constrained pickup and delivery of full truckloads
http://www.sciencedirect.com/science/article/B6VCT-47S6S3F-3/2/073d18e82008a5fc63788e41d36ac407
Gronalt, Manfred
Hartl, Richard F.
Reimann, Marc
oai:RePEc:eee:ejores:v:176:y:2007:i:1:p:445-4672009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:176:y:2007:i:1:p:445-467
article
A duopoly model with heterogeneous congestion-sensitive customers
http://www.sciencedirect.com/science/article/B6VCT-4HNSB38-4/2/c88c35b71d0126f2667a33940cf4d7a9
Mandjes, Michel
Timmer, Judith
oai:RePEc:eee:ejores:v:103:y:1997:i:1:p:209-2292009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:103:y:1997:i:1:p:209-229
article
Exact algorithms for the stochastic shortest path problem with a decreasing deadline utility function
http://www.sciencedirect.com/science/article/B6VCT-3SX4N53-1J/2/92a0aa9ab046e88e6c53aba1526de288
Murthy, Ishwar
Sarkar, Sumit
oai:RePEc:eee:ejores:v:29:y:1987:i:3:p:307-3162009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:29:y:1987:i:3:p:307-316
article
On the expected value of stochastic linear programs and (dynamic) network flow problems
http://www.sciencedirect.com/science/article/B6VCT-4B4RTT1-82/2/99b1b16cb734b4f34bcf3f4f0e0439e9
Fincke, Ulrich
Hamacher, Horst W.
oai:RePEc:eee:ejores:v:125:y:2000:i:2:p:292-2972009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:125:y:2000:i:2:p:292-297
article
Stability in P5- and banner-free graphs
http://www.sciencedirect.com/science/article/B6VCT-40JNF3F-9/2/60f5805f2f683d28870aa0db419cb6b3
Lozin, V. V.
oai:RePEc:eee:ejores:v:59:y:1992:i:3:p:359-3692009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:59:y:1992:i:3:p:359-369
article
Many steps towards zero inventory
http://www.sciencedirect.com/science/article/B6VCT-48NBG7Y-1T7/2/45e6aa0f52ecca9ab9483aedf9a869ba
Grunwald, Herbert J.
Fortuin, Leonard
oai:RePEc:eee:ejores:v:168:y:2006:i:3:p:716-7312009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:168:y:2006:i:3:p:716-731
article
An linear programming based lower bound for the simple assembly line balancing problem
http://www.sciencedirect.com/science/article/B6VCT-4D98KSM-2/2/2c8c6605fe04adb5d0a9404cefe9aff6
Peeters, Marc
Degraeve, Zeger
oai:RePEc:eee:ejores:v:32:y:1987:i:3:p:333-3392009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:32:y:1987:i:3:p:333-339
article
Choosing an electronic cardiac pacemaker: A decision analysis
http://www.sciencedirect.com/science/article/B6VCT-4GK296W-2/2/03c72c0dba493ac9c96e0f378a48639a
Pliskin, Joseph S.
Ronen, Boaz
Feldman, Shlomo
oai:RePEc:eee:ejores:v:65:y:1993:i:1:p:96-1172009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:65:y:1993:i:1:p:96-117
article
Safety stock allocation in a two-echelon distribution system
http://www.sciencedirect.com/science/article/B6VCT-48M3FT6-4X/2/4dda8af3a3bacf69cf604d3b6f576b25
Tempelmeier, Horst
oai:RePEc:eee:ejores:v:11:y:1982:i:1:p:26-342009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:11:y:1982:i:1:p:26-34
article
A long-term analysis of transport in Europe: Some implications for transport policy and research
http://www.sciencedirect.com/science/article/B6VCT-4H9PHHN-5/2/467286df94e9fd1f95c27080c50f4268
Holst, Olav
oai:RePEc:eee:ejores:v:142:y:2002:i:1:p:174-1862009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:142:y:2002:i:1:p:174-186
article
Evaluating the best main battle tank using fuzzy decision theory with linguistic criteria evaluation
http://www.sciencedirect.com/science/article/B6VCT-468DBBK-4/2/158cdfc7593b72846f67a135e95b4735
Cheng, Ching-Hsue
Lin, Yin
oai:RePEc:eee:ejores:v:108:y:1998:i:3:p:551-5702009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:108:y:1998:i:3:p:551-570
article
Performance characteristics of alternative genetic algorithmic approaches to the traveling salesman problem using path representation: An empirical study
http://www.sciencedirect.com/science/article/B6VCT-3TMR6M6-S/2/f2f66f2987383d564aac0fbc5f0ad82c
Schmitt, Lawrence J.
Amini, Mohammad M.
oai:RePEc:eee:ejores:v:187:y:2008:i:3:p:719-7452009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:187:y:2008:i:3:p:719-745
article
Game-theoretic analysis of cooperation among supply chain agents: Review and extensions
http://www.sciencedirect.com/science/article/B6VCT-4M877F3-5/2/1dc1c881236341b20bdb66010b2ed9a0
Nagarajan, Mahesh
Sosic, Greys
oai:RePEc:eee:ejores:v:158:y:2004:i:2:p:390-3982009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:158:y:2004:i:2:p:390-398
article
Towards multicriteria clustering: An extension of the k-means algorithm
http://www.sciencedirect.com/science/article/B6VCT-49PYPHD-G/2/359d3b758184177b565e79828b4d930c
De Smet, Yves
Montano Guzman, Linett
oai:RePEc:eee:ejores:v:46:y:1990:i:3:p:304-3122009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:46:y:1990:i:3:p:304-312
article
A super criterion for testing portfolio efficiency: Empirical evidence on Finnish stock data
http://www.sciencedirect.com/science/article/B6VCT-48VW7ND-CR/2/4427753944e1763edb2f9779c712e3ab
Ostermark, R.
oai:RePEc:eee:ejores:v:138:y:2002:i:3:p:569-5772009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:138:y:2002:i:3:p:569-577
article
Decomposed vs integrated control of a one-stage production system
http://www.sciencedirect.com/science/article/B6VCT-451NGBW-9/2/6bfba5dfcbcf92cf4dc7a52360413b09
Broersma, Andreas L. A.
Sierksma, Gerard
Wijngaard, Jacob
oai:RePEc:eee:ejores:v:106:y:1998:i:1:p:129-1362009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:106:y:1998:i:1:p:129-136
article
Evaluation of rankings with regard to the possible number of agreements and conflicts
http://www.sciencedirect.com/science/article/B6VCT-3SX82DN-1C/2/6c9556fa8da705a2ff4352e41cc76353
Ray, Thomas G.
Triantaphyllou, Evangelos
oai:RePEc:eee:ejores:v:73:y:1994:i:1:p:50-542009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:73:y:1994:i:1:p:50-54
article
EOQ models with general demand and holding cost functions
http://www.sciencedirect.com/science/article/B6VCT-48NBMSJ-3KC/2/b0a180e4409caca1779d67307d86447c
Goh, M.
oai:RePEc:eee:ejores:v:147:y:2003:i:2:p:345-3642009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:147:y:2003:i:2:p:345-364
article
Scheduling parallel dedicated machines under a single non-shared resource
http://www.sciencedirect.com/science/article/B6VCT-45J90PP-D/2/fc60428ae1b6429f913e49815bb77b9a
Kellerer, H.
Strusevich, V. A.
oai:RePEc:eee:ejores:v:130:y:2001:i:3:p:653-6642009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:130:y:2001:i:3:p:653-664
article
Using fuzzy integral for evaluating subjectively perceived travel costs in a traffic assignment model
http://www.sciencedirect.com/science/article/B6VCT-42FS7FG-G/2/209fda1c95a797b6a55da594e3a5626c
Chen, Yuh-Wen
Tzeng, Gwo-Hshiung
oai:RePEc:eee:ejores:v:140:y:2002:i:3:p:541-5612009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:140:y:2002:i:3:p:541-561
article
A goal programming approach to strategic resource allocation in acute care hospitals
http://www.sciencedirect.com/science/article/B6VCT-45PRYHR-2/2/c1070cc577b3eee2ad6c3ae1e1a6e3a9
Blake, John T.
Carter, Michael W.
oai:RePEc:eee:ejores:v:161:y:2005:i:1:p:224-2392009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:161:y:2005:i:1:p:224-239
article
On a dual queueing system with preemptive priority service discipline
http://www.sciencedirect.com/science/article/B6VCT-4B0SW98-2/2/d5c6f630c117e06a79e4770c6540e627
Bedford, A.
Zeephongsekul, P.
oai:RePEc:eee:ejores:v:191:y:2008:i:3:p:816-8372009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:191:y:2008:i:3:p:816-837
article
Robust optimization using computer experiments
During metamodel-based optimization three types of implicit errors are typically made. The first error is the simulation-model error, which is defined by the difference between reality and the computer model. The second error is the metamodel error, which is defined by the difference between the computer model and the metamodel. The third is the implementation error. This paper presents new ideas on how to cope with these errors during optimization, in such a way that the final solution is robust with respect to these errors. We apply the robust counterpart theory of Ben-Tal and Nemirovsky to the most frequently used metamodels: linear regression and Kriging models. The methods proposed are applied to the design of two parts of the TV tube. The simulation-model errors receive little attention in the literature, while in practice these errors may have a significant impact due to propagation of such errors.
http://www.sciencedirect.com/science/article/B6VCT-4NKYNTJ-3/1/9aed541b2a1a94b95cb63de2601863c0
Stinstra, Erwin
den Hertog, Dick
oai:RePEc:eee:ejores:v:97:y:1997:i:1:p:183-1992009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:97:y:1997:i:1:p:183-199
article
Algorithms for network piecewise-linear programs: A comparative study
http://www.sciencedirect.com/science/article/B6VCT-49V617R-N/2/6b1b2d10a4902178319297b6ebc33c9c
Marins, Fernando A. S.
Senne, Edson L. F.
Darby-Dowman, Ken
Machado, Arlene F.
Perin, Clovis
oai:RePEc:eee:ejores:v:181:y:2007:i:3:p:1198-12132009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:181:y:2007:i:3:p:1198-1213
article
Challenges of continuous global optimization in molecular structure prediction
http://www.sciencedirect.com/science/article/B6VCT-4JRVDXB-C/2/4a03a18b4dfd0059f5d37688711d42a6
Beliakov, Gleb
Lim, Kieran F.
oai:RePEc:eee:ejores:v:149:y:2003:i:1:p:65-762009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:149:y:2003:i:1:p:65-76
article
On identifying dominant cliques
http://www.sciencedirect.com/science/article/B6VCT-47MJ2JD-7/2/3400a51ca1c4761a6d464e236fe5d48f
Escudero, L. F.
Munoz, S.
oai:RePEc:eee:ejores:v:51:y:1991:i:3:p:327-3372009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:51:y:1991:i:3:p:327-337
article
Stochastic optimization of reservation systems
http://www.sciencedirect.com/science/article/B6VCT-48NBFXJ-1PG/2/4a163f7a1510d2f17b690f2e63d65f34
Virtamo, Jorma T.
Aalto, Samuli
oai:RePEc:eee:ejores:v:187:y:2008:i:3:p:1184-11952009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:187:y:2008:i:3:p:1184-1195
article
Flow-shop scheduling with setup and assembly operations
http://www.sciencedirect.com/science/article/B6VCT-4MBC52D-4/2/0a76b4c930817b41e7cc86866504d09a
Yokoyama, Masao
oai:RePEc:eee:ejores:v:104:y:1998:i:3:p:521-5312009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:104:y:1998:i:3:p:521-531
article
A parallel implementation of the PROMETHEE method
http://www.sciencedirect.com/science/article/B6VCT-3SX6GTB-1G/2/b81e6bb1bb735d74fe7fcc1651d1c8c9
Dias, Luis C.
Costa, Joao P.
Climaco, Joao N.
oai:RePEc:eee:ejores:v:145:y:2003:i:3:p:660-6642009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:145:y:2003:i:3:p:660-664
article
Effects of multiple arbitrators on final-offer arbitration settlements
http://www.sciencedirect.com/science/article/B6VCT-45BRS7S-2/2/b3f04c810460cdd8d4dd0e2e4f8ab640
Hurley, W. J.
oai:RePEc:eee:ejores:v:126:y:2000:i:3:p:567-5862009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:126:y:2000:i:3:p:567-586
article
Analysis of reactive scheduling problems in a job shop environment
http://www.sciencedirect.com/science/article/B6VCT-4135XF5-B/2/6cb46f365829f1018fc6646eebbe56b3
Sabuncuoglu, I.
Bayiz, M.
oai:RePEc:eee:ejores:v:169:y:2006:i:3:p:943-9592009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:169:y:2006:i:3:p:943-959
article
A study of stochastic local search algorithms for the biobjective QAP with correlated flow matrices
http://www.sciencedirect.com/science/article/B6VCT-4DN14KG-1/2/99ecc2c3f99fb1a191d4cc07217ac5c3
Paquete, Luis
Stutzle, Thomas
oai:RePEc:eee:ejores:v:190:y:2008:i:1:p:79-892009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:190:y:2008:i:1:p:79-89
article
A BSSS algorithm for the single facility location problem in two regions with different norms
Suppose the plane is divided by a straight line into two regions with different norms. We want to find the location of a single new facility such that the sum of the distances from the existing facilities to this point is minimized. This is in fact a non-convex optimization problem. The main difficulty is caused by finding the distances between points on different sides of the boundary line. In this paper we present a closed form solution for finding these distances. We also show that the optimal solution lies in the rectangular hull of the existing points. Based on these findings then, an efficient big square small square (BSSS) procedure is proposed.
http://www.sciencedirect.com/science/article/B6VCT-4NXXM9V-4/1/bd9df90643ec6447caff83ad6fb0f984
Zaferanieh, M.
Taghizadeh Kakhki, H.
Brimberg, J.
Wesolowsky, G.O.
oai:RePEc:eee:ejores:v:163:y:2005:i:3:p:776-7832009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:163:y:2005:i:3:p:776-783
article
An EOQ model for perishable items under stock-dependent selling rate and time-dependent partial backlogging
http://www.sciencedirect.com/science/article/B6VCT-4BBHCRJ-2/2/455eb4139e3788a94c0af18de9b221ba
Dye, Chung-Yuan
Ouyang, Liang-Yuh
oai:RePEc:eee:ejores:v:130:y:2001:i:1:p:169-1892009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:130:y:2001:i:1:p:169-189
article
Human resource planning in knowledge-intensive operations: A model for learning with stochastic turnover
http://www.sciencedirect.com/science/article/B6VCT-426XWHV-G/2/b8b7aaff48100e9bcddef3bb5383e971
Bordoloi, Sanjeev K.
Matsuo, Hirofumi
oai:RePEc:eee:ejores:v:191:y:2008:i:1:p:253-2632009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:191:y:2008:i:1:p:253-263
article
Flexible supply contracts under price uncertainty
This article develops supply contracts covering environments with changing prices. We investigate characterization properties of the price processes, while considering costs and discount factors. We determine expressions of the contract's expected low price and its second moment for a given horizon. We then employ these expected price and second moment values to identify an expected optimum time before the contract expires at which the lowest price occurs. Simulation experiments verify our analysis, and they illustrate how the optimum purchase time decreases as the drift term increases.
http://www.sciencedirect.com/science/article/B6VCT-4PHBWSG-1/1/3011764bdbe924f9c8cc6da7c7a00b63
Fotopoulos, S.B.
Hu, X.
Munson, C.L.
oai:RePEc:eee:ejores:v:80:y:1995:i:2:p:410-4172009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:80:y:1995:i:2:p:410-417
article
Using AHP for resource allocation problems
http://www.sciencedirect.com/science/article/B6VCT-4031TH0-17/2/b55cc02446ce3c29fdb2e16c7e9b3d53
Ramanathan, R.
Ganesh, L. S.
oai:RePEc:eee:ejores:v:183:y:2007:i:1:p:472-4782009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:183:y:2007:i:1:p:472-478
article
Random effects logistic regression model for default prediction of technology credit guarantee fund
http://www.sciencedirect.com/science/article/B6VCT-4MJBTM8-8/2/94133447b785f9d9d5da7401240d24e4
Sohn, So Young
Kim, Hong Sik
oai:RePEc:eee:ejores:v:77:y:1994:i:1:p:154-1682009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:77:y:1994:i:1:p:154-168
article
Procedures for solving a 1-dimensional cutting problem
http://www.sciencedirect.com/science/article/B6VCT-48NBHG3-27K/2/adc123dc033afd6b98b081f33e6ea161
Corominas, Albert
Bautista, Joaquin
oai:RePEc:eee:ejores:v:174:y:2006:i:3:p:1664-16842009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:174:y:2006:i:3:p:1664-1684
article
Optimizing delivery lead time/inventory placement in a two-stage production/distribution system
http://www.sciencedirect.com/science/article/B6VCT-4H87GD5-1/2/f0863c898bfe3f7091d7f5b5b4aec0f3
Barnes-Schuster, Dawn
Bassok, Yehuda
Anupindi, Ravi
oai:RePEc:eee:ejores:v:69:y:1993:i:2:p:177-1862009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:69:y:1993:i:2:p:177-186
article
A duopoly model of pricing for inventory liquidation
http://www.sciencedirect.com/science/article/B6VCT-48NBGX1-21F/2/c9cc11ba96902365108c7fbfffc55f46
Bikhchandani, Sushil
Mamer, John W.
oai:RePEc:eee:ejores:v:151:y:2003:i:3:p:617-6322009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:151:y:2003:i:3:p:617-632
article
Determinants of mutual fund underperformance: A Bayesian stochastic frontier approach
http://www.sciencedirect.com/science/article/B6VCT-47RRW2X-1/2/8f481e573c8dc740bf237efc8feebd9d
Annaert, Jan
van den Broeck, Julien
Vander Vennet, Rudi
oai:RePEc:eee:ejores:v:24:y:1986:i:2:p:216-2272009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:24:y:1986:i:2:p:216-227
article
Linear, quadratic, and bilinear programming approaches to the linear complementarity problem
http://www.sciencedirect.com/science/article/B6VCT-48MYGYR-2R/2/56dc8f5d85a1d9b41096269f313e9c72
Al-Khayyal, Faiz A.
oai:RePEc:eee:ejores:v:16:y:1984:i:3:p:365-3772009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:16:y:1984:i:3:p:365-377
article
Parsimonious modelling and forecasting of seasonal time series
http://www.sciencedirect.com/science/article/B6VCT-48NB99C-16/2/c5bcf59ca347e18dd083161ddd01ece9
Roberts, S. A.
Harrison, P. J.
oai:RePEc:eee:ejores:v:75:y:1994:i:1:p:1-122009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:75:y:1994:i:1:p:1-12
article
A review of optimisation models of Kanban-based production systems
http://www.sciencedirect.com/science/article/B6VCT-48NBCY4-XF/2/28b0d82d2fe5a709611be756386c865e
Price, Wilson
Gravel, Marc
Nsakanda, Aaron Luntala
oai:RePEc:eee:ejores:v:195:y:2009:i:1:p:89-972009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:195:y:2009:i:1:p:89-97
article
Single machine scheduling to minimize total weighted earliness subject to minimal number of tardy jobs
Motivated by just-in-time manufacturing, we consider a single machine scheduling problem with dual criteria, i.e., the minimization of the total weighted earliness subject to minimum number of tardy jobs. We discuss several dominance properties of optimal solutions. We then develop a heuristic algorithm with time complexity O(n3) and a branch and bound algorithm to solve the problem. The computational experiments show that the heuristic algorithm is effective in terms of solution quality in many instances while the branch and bound algorithm is efficient for medium-size problems.
Scheduling Single machine Dual criteria Earliness Number of tardy jobs
http://www.sciencedirect.com/science/article/B6VCT-4RR8YR5-7/2/f074e4e6dc7046e9a2c5824a3a874a27
Wan, Guohua
Yen, Benjamin P.-C.
oai:RePEc:eee:ejores:v:128:y:2001:i:1:p:129-1462009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:128:y:2001:i:1:p:129-146
article
A heuristic for single machine scheduling with early and tardy costs
http://www.sciencedirect.com/science/article/B6VCT-41Y1XYH-8/2/0eb87e75e95b377279e758c86d5dc670
Mazzini, Renata
Armentano, Vinicius A.
oai:RePEc:eee:ejores:v:155:y:2004:i:2:p:299-3162009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:155:y:2004:i:2:p:299-316
article
Retaining students in retail banking through price bundling: Evidence from the Swedish market
http://www.sciencedirect.com/science/article/B6VCT-48BC1MB-3/2/e3f9e78d1df52f617972f99c3fe7e2f9
Mankila, Merja
oai:RePEc:eee:ejores:v:116:y:1999:i:2:p:249-2582009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:116:y:1999:i:2:p:249-258
article
A multi-server queueing model with locking
http://www.sciencedirect.com/science/article/B6VCT-3W49TS5-2/2/f1e95da5de671711951f4402fee16c97
Adan, Ivo
de Kok, Ton
Resing, Jacques
oai:RePEc:eee:ejores:v:173:y:2006:i:2:p:556-5642009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:173:y:2006:i:2:p:556-564
article
Locating an obnoxious plane
http://www.sciencedirect.com/science/article/B6VCT-4G65V6S-5/2/f9e0841c34d1daf2d2938c3e8d79fc47
Diaz-Banez, J.M.
Lopez, M.A.
Sellares, J.A.
oai:RePEc:eee:ejores:v:124:y:2000:i:2:p:221-2232009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:124:y:2000:i:2:p:221-223
article
Management science and operations research in China
http://www.sciencedirect.com/science/article/B6VCT-4066S51-1/2/b4ffe739d82521984166b934dacd8e52
Li, Huaizu
Wang, Shouyang
Xu, Li D
oai:RePEc:eee:ejores:v:80:y:1995:i:2:p:277-2962009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:80:y:1995:i:2:p:277-296
article
Specialized inspection problems in serial production systems
http://www.sciencedirect.com/science/article/B6VCT-4031TH0-S/2/2df922dae700fad1f13bddd4af1d301e
Rebello, Ranjit
Agnetis, Alessandro
Mirchandani, Pitu B.
oai:RePEc:eee:ejores:v:166:y:2005:i:1:p:93-1142009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:166:y:2005:i:1:p:93-114
article
A new fuzzy multiple attributive group decision making methodology and its application to propulsion/manoeuvring system selection problem
http://www.sciencedirect.com/science/article/B6VCT-4CB0BN5-1/2/12089c8ccb5e71c5bf58e2aadcf54825
Olcer, A. I.
Odabasi, A. Y.
oai:RePEc:eee:ejores:v:144:y:2003:i:3:p:646-6582009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:144:y:2003:i:3:p:646-658
article
Channel redistribution with direct selling
http://www.sciencedirect.com/science/article/B6VCT-45CW35F-1/2/1ae97942de42b524b57ef41d13430361
Yao, Dong-Qing
Liu, John J.
oai:RePEc:eee:ejores:v:51:y:1991:i:1:p:100-1092009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:51:y:1991:i:1:p:100-109
article
On the complexity of generalized due date scheduling problems
http://www.sciencedirect.com/science/article/B6VCT-48NBD8J-13M/2/ed4ea17c8b0d9d8168e4be079dc23f44
Hall, Nicholas G.
Sethi, Suresh P.
Sriskandarajah, Chelliah
oai:RePEc:eee:ejores:v:170:y:2006:i:1:p:132-1432009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:170:y:2006:i:1:p:132-143
article
Partially adaptive robust estimation of regression models and applications
http://www.sciencedirect.com/science/article/B6VCT-4D58D5S-1/2/c6f5fc85dc07ce09d2f9c1940570796c
Hansen, James V.
McDonald, James B.
Turley, Robert S.
oai:RePEc:eee:ejores:v:89:y:1996:i:2:p:285-3012009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:89:y:1996:i:2:p:285-301
article
A generalized maintenance model for stochastically deteriorating equipment
http://www.sciencedirect.com/science/article/B6VCT-3VW1D7P-27/2/b00f83ce53d882f76d681aa3ed4cc96f
Stadje, Wolfgang
Zuckerman, Dror
oai:RePEc:eee:ejores:v:94:y:1996:i:1:p:97-1052009-04-22RePEc:eee:ejores
RePEc:eee:ejores:v:94:y:1996:i:1:p:97-105
article
On finding a biconnected spanning planar subgraph with applications to the facilities layout problem
http://www.sciencedirect.com/science/article/B6VCT-3VV42S8-1C/2/adf0c500599ac7f8190032077c7def6a
Goldschmidt, Olivier
Takvorian, Alexis
Yu, Gang
oai:RePEc:eee:ejores:v:40:y:1989:i:1:p:38-422009-04-22RePEc:eee:ejores