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Mathematical Programming Model (mathematical + programming_model)
Selected AbstractsHuman and machine effects in a just-in-time scheduling problemHUMAN FACTORS AND ERGONOMICS IN MANUFACTURING & SERVICE INDUSTRIES, Issue 4 2009Tamer Eren In this article, single-machine scheduling problems with learning effects of setup and removal times and deterioration effects of processing time are considered. The objective function of the problem is minimization of the weighted sum of total earliness and total tardiness. To get an exact solution to the problem, a mathematical programming model is proposed. Also the model is tested on an example. To the best of our knowledge, no work exists in the literature that considers the problem presented in this article. © 2009 Wiley Periodicals, Inc. [source] A Mathematical Programming Approach for Procurement Using Activity Based CostingJOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 1-2 2000Zeger Degraeve Activity Based Costing and Management are important topics in today's management accounting literature. While there has been much attention paid in the Activity Based Costing literature to customer profitability analysis, process improvement and product design, there has been far less notice taken of purchasing. In this paper we develop an Activity Based Costing approach for the determination of procurement strategies. Vendor selection using an Activity Based Costing approach is choosing the combination of suppliers for a given product group that minimizes the total costs associated with the purchasing strategy. To this end we develop a mathematical programming model where decisions involve the selection of vendors and the determination of order quantities. The system computes the total cost of ownership, thereby increasing the objectivity in the selection process and giving the opportunity for various kinds of sensitivity analysis. [source] Production planning with resources subject to congestionNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 2 2009Jakob Asmundsson Abstract A fundamental difficulty in developing effective production planning models has been accurately reflecting the nonlinear dependency between workload and lead times. We develop a mathematical programming model for production planning in multiproduct, single stage systems that captures the nonlinear dependency between workload and lead times. We then use outer linearization of this nonlinear model to obtain a linear programming formulation and extend it to multistage systems. Extensive computational experiments validate the approach and compare its results to conventional models that assume workload-independent planning lead times. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009 [source] Impacts of climate change on lower Murray irrigation,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 3 2009Jeff Connor This article evaluates irrigated agriculture sector response and resultant economic impacts of climate change for a part of the Murray Darling Basin in Australia. A water balance model is used to predict reduced basin inflows for mild, moderate and severe climate change scenarios involving 1, 2 and 4°C warming, and predict 13, 38 and 63% reduced inflows. Impact on irrigated agricultural production and profitability are estimated with a mathematical programming model using a two-stage approach that simultaneously estimates short and long-run adjustments. The model accounts for a range of adaptive responses including: deficit irrigation, temporarily following of some areas, permanently reducing the irrigated area and changing the mix of crops. The results suggest that relatively low cost adaptation strategies are available for a moderate reduction in water availability and thus costs of such a reduction are likely to be relatively small. In more severe climate change scenarios greater costs are estimated. Adaptations predicted include a reduction in total area irrigated and investments in efficient irrigation. A shift away from perennial to annual crops is also predicted as the latter can be managed more profitably when water allocations in some years are very low. [source] Market-Based Policy Instruments, Irrigation Water Demand, and Crop Diversification in the Bow River Basin of Southern AlbertaCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2010Lixia He This paper investigates two market-based policy instruments, short-term water trading and volumetric water pricing, in a jurisdiction where historical water allocations are based on the seniority of appropriative water rights. The analysis identifies the potential effects of alternative surface water allocations on crop choices and on producer incomes in three irrigation districts in the Bow River Sub-basin of the South Saskatchewan River. The short-run effects of these alternative policy instruments are examined in scenarios where seasonal water supplies are reduced by 10,30% relative to the 2003 water usage levels. An important contribution of the paper is to present a computational, positive mathematical programming model that integrates both irrigation decisions and specific crop choices when characterizing agents' optimal responses to moderate water scarcity. The numerical results illustrate the manner in which the use of these market-based economic instruments can increase the irrigated land area and economic welfare relative to the allocations made based only on the seniority of water rights. Under full information with no transactions costs, the use of water pricing for allocation purposes can achieve the same production outcomes as could be reached under short-term water trading. However, the distribution of potential monetary gains and losses among agents would vary considerably across policies. Le présent article étudie deux instruments de politique fondés sur le marché, soit le commerce de l'eau à court terme et l'établissement du prix de l'eau en fonction du volume, dans une province où l'attribution de l'eau est historiquement fondée sur l'ancienneté des droits d'appropriation de l'eau. L'analyse a exposé les effets potentiels de divers moyens d'attribution de l'eau de surface sur le choix des cultures et le revenu des producteurs dans trois districts d'irrigation situés dans le sous-bassin de la rivière Bow qui s'écoule dans le sous-bassin de la rivière Saskatchewan Sud. Nous avons examiné les effets à court terme de ces moyens dans des scénarios où les approvisionnements saisonniers en eau ont été réduits de 10 à 30 p. 100 par rapport aux niveaux d'utilisation de l'eau établis en 2003. Le présent article visait, entre autres, à présenter un modèle de programmation mathématique positive intégrant à la fois les décisions concernant l'irrigation et le choix de cultures spécifiques au moment de caractériser les réactions optimales des agents face à une rareté modérée de l'eau. Les résultats numériques ont montré de quelle façon l'utilisation de ces instruments économiques fondés sur le marché pouvait accroître les superficies irriguées et le bien-être économique comparativement à l'attribution de l'eau fondée sur l'ancienneté des droits d'appropriation de l'eau. Selon les renseignements complets sans coûts de transaction, le recours à l'établissement du prix de l'eau en fonction du volume et le commerce de l'eau à court terme peuvent permettre d'obtenir les mêmes résultats en matière de production. Toutefois, la répartition des pertes et des gains éventuels entre les agents varieraient considérablement d'une politique à l'autre. [source] |