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581.
582.
We consider a supply chain design problem where the decision maker needs to decide the number and locations of the distribution centers (DCs). Customers face random demand, and each DC maintains a certain amount of safety stock in order to achieve a certain service level for the customers it serves. The objective is to minimize the total cost that includes location costs and inventory costs at the DCs, and distribution costs in the supply chain. We show that this problem can be formulated as a nonlinear integer programming model, for which we propose a Lagrangian relaxation based solution algorithm. By exploring the structure of the problem, we find a low-order polynomial algorithm for the nonlinear integer programming problem that must be solved in solving the Lagrangian relaxation sub-problems. We present computational results for several instances of the problem with sizes ranging from 40 to 320 customers. Our results show the benefits of having an integrated supply chain design framework that includes location, inventory, and routing decisions in the same optimization model. 相似文献
583.
Ricardo Saraiva de Camargo Gilberto de Miranda Arne Løkketangen 《Applied Mathematical Modelling》2013,37(12-13):7465-7480
An important problem of the freight industry is the parcel delivery network design, where several facilities are responsible for assembling flows from several origins, re-routing them to other facilities where the flows are disassembled and the packages delivered to their final destinations. In order to provide this service, local tours are established for the vehicles assigned to each of the processing facilities, which are then responsible for the pickup and delivery tasks. This application gives rise to the many-to-many hub location routing problem that is the combination of two well known problems: the vehicle routing problem and the single assignment hub location problem. In this work, a new formulation for this important problem is proposed and solved by a specially tailored Benders decomposition algorithm. The proposed method is robust enough to solve instances up to 100 nodes having 4 million integer variables. 相似文献
584.
优化配送中心订单拣取路径的一种动态规划方法 总被引:5,自引:0,他引:5
订单拣取过程是配送中心最耗时耗力的作业环节,因此提高拣货作业效率成了大多数配送中心努力的方向。而优化拣货路径则是提高拣货作业效率的有效措施之一,所以本在传统拣货规则的基础上,提出了一种采用动态规划方法优化订单拣取路径的方法。该方法是优化配送中心订单掠取路径的一种新的思路和方法,且其确定的拣货路径是在既定规则下的最优拣货路径。针对不同的拣货单采用不同的拣货路径,能有效缩短拣货行走的距离,对提高配送中心的拣货效率具有现实意义。 相似文献
585.
This paper presents a modification of the well-known Solomon (1987) sequential insertion heuristic I1 for the Vehicle Routing
Problem with Time Windows (VRPTW). VRPTW involves servicing customers within a pre-specified service time window by homogeneously
capacitated vehicles from a single depot. By using two new measures for the additional time needed to insert a customer in
the route, significantly better solutions are obtained for relatively short routes compared to the original Solomon (1987)
sequential insertion heuristic I1. Because high-quality initial heuristics often allow local searches and metaheuristics to
achieve better solutions more quickly, the new approach is likely to help generating better solutions to practical routing
problems. 相似文献
586.
587.
提出一种改进的蚁群算法优化应急物流配送车辆路径问题算法,设计了应急物流配送车辆路径问题的数学模型,并利用计算机进行了仿真实验.实验结果表明,方法能有效解决应急物流配送车辆路径问题,具有一定的理论价值和实际意义. 相似文献
588.
求解车辆路径问题的免疫算法 总被引:1,自引:0,他引:1
将免疫算法用于求解车辆路径问题,并根据车辆路径问题的具体情况提出了一种基于分组匹配的亲和力计算方法.实验结果表明,免疫算法能有效地应用于车辆路径问题. 相似文献
589.