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141.
This paper studies coordination mechanisms in a supply chain which consists of two suppliers with capacity uncertainties selling differential yet substitutable products through a common retailer who faces price-sensitive random demand of these two products. We develop in a noncompetitive setting three coordination models – revenue sharing, return policy, and combination of revenue sharing and return policy – and contrast them with a basic and uncoordinated model. We are able to establish the ordinal relationship among the retailer’s ordering and pricing decisions and analytically compare the performances between certain models when two suppliers are identical. We find that the retailer’s ordering and pricing decisions in the model with return policy in the case of identical suppliers are independent of demand or supply uncertainty. Our numerical results reveal that the performances of coordination models in the case of nonidentical suppliers resemble those in the case of identical suppliers. We find that the retailer will place a larger order quantity in models where her average cost per unit sold is smaller. We also find that product substitutability and uncertainties have different effects on chain performances. 相似文献
142.
本文研究了三种物资同时段需求的EOQ模型,从理论以及实例均说明了该模型相对单一物资的EOQ模型,能够缩小这三种物资对仓库的占用空间,该模型在实际问题中要求需求和采购价格均随着时间的变化而变化,通过算法计算得到了满足三种物资同时段需求的最佳采购次数,最后得出了所要建立满足需求的最小仓库容量. 相似文献
143.
Transportation problems are important complex systems because of the increased number of vehicles in cities. In this paper, we study time series of vehicle demand by using the ferry-boat system between Salvador city and Itaparica island, in Bahia, Brazil. We compare the traditional demand analysis (ARIMA method) with the self-affine ones (the scaling exponent α and the density of crossing points ρ). In addition, taking into account the inherent self-affine behavior we study the stationary states of this dynamic process by using a nonlinear Fokker-Planck equation. The present findings indicate that the scaling exponent α describes some properties of flux of vehicles using the ferry-boat system. The behavior of α gives an alternative explanation about demand analysis, and the nonlinear Fokker-Planck equation presents a solution close to the stationary behavior of this complex dynamical analysis. 相似文献
144.
This paper examines the effectiveness of sonolysis in improving the anaerobic biodegradability of the organic fraction of municipal solid waste coming from mechanical selection, thus enhancing biogas production and energy recovery as well.Methane yield of solid organic material anaerobic digestion is significantly affected by substrate availability that was evaluated, in this investigation, through organic matter solubilisation tests carried out at different conditions of ultrasound treatment. Results show that sonolysis can significantly improve the solubilisation of organic solid waste, thus allowing higher biogas production from anaerobic treatment of sonicated substrates. After 45 days, the biogas produced during anaerobic codigestion tests for the sonicated mixture was 24% higher than untreated one.Therefore, these results can lay the basis for the development of technologies useful to produce high biogas quantities, in order to improve clean energy generation from biowaste. 相似文献
145.
146.
We study the effects of demand uncertainty on optimal decisions and the expected profit of a price-setting newsvendor who faces either additive or multiplicative stochastic demand. Our key findings are as follows. (1) A stochastically larger demand may even lead to a smaller order size and a lower profit when price is endogenous. (2) A stochastically larger demand will lead to a higher selling price in general for the additive demand case but to a lower selling price under certain mild conditions for the multiplicative demand case. Moreover, if the larger demand can be represented by a transformation of the lower one, it will lead to a higher expected profit for both demand cases. However, except for the setting with a zero shortage cost, a larger demand may not necessarily result in a higher expected profit in general. (3) Under mild conditions, a less variable demand will lead to a higher and lower selling price for the additive and multiplicative demand case, respectively, and a higher expected profit for both cases. 相似文献
147.
Vera Hemmelmayr Karl F. Doerner Richard F. Hartl Martin W.P. Savelsbergh 《European Journal of Operational Research》2010,202(3):7
We develop technology to plan delivery routes for the supply of blood products to hospitals by a blood bank. The technology produces low cost, robust plans that hedge against the natural uncertainty associated with blood product usage at hospitals. The technology relies on sampling-based approaches involving integer programming and variable neighborhood search. An extensive computational study shows the efficacy of the two approaches and highlights the impact of product usage uncertainty on the resulting delivery plans. 相似文献
148.