考虑区位协同的海外仓选址及运输规划研究

越来越多的跨境电商平台选择在境外建设海外仓以解决跨境物流供应链问题，海外仓已成为众多国内跨境电商平台海外扩张的刚性需求。本文针对考虑不同区位海外仓之间货物协同转运的海外仓选址及运输规划问题，构建了最小化建仓及运输成本的两阶段数学规划模型，并提出采用网络流图的方式精确求解特殊情况下的货物分配问题。以在日本建设海外仓为例，分析了单位面积海外仓货物容纳数量与区位转运费用对海外仓选址及货物运输方案的影响。结果表明，在考虑区位协同运输的情况下，本文提出的模型与方法能够有效解决海外仓的选址及运输规划问题。     

越库配送下考虑时空距离的库门分配与车辆调度优化

针对越库配送下考虑时空距离的库门分配与车辆路径问题,建立以车辆派遣成本、运输成本、时间惩罚成本、越库内部操作成本总和最小化为目标的库门分配与车辆路径优化模型。根据问题的特征设计改进的自适应遗传算法,并根据时空距离生成初始解。通过对不同规模的算例进行对比和分析,验证了模型的正确性和算法的有效性,结果表明,所得出的库门分配和车辆调度优化方案可以有效降低越库配送中心的运营成本。研究成果拓展和丰富了越库配送下的车辆路径问题研究,能为物流企业优化配送方案提供理论依据。     

带货物权重的车辆路径问题及遗传算法

考虑一个分销中心、多个零售商组成的分销网络系统中具有柔性车辆能力的带货物权重的车辆路径问题.并根据车辆的满载情况采用了不同的运输策略,即单点运输和多点运输方式.在多点运输方式下,与以往诸多研究不同的是,文章建立了一种基于货物权重的VRP模型——WVRP,即在安排车辆线路时每个零售商的货物需求量也作为一个因素考虑,尽可能使车辆优先供货需求量较大的零售商.最后,针对问题的性质,开发了一种基于划分的遗传算法PB-GA对问题进行求解,并与一般遗传算法及常用的启发式算法进行了分析比较.     

装卸一体化的车辆路径问题及基于插入法的新禁忌算法

在日益激烈的市场竞争中,如何在降低成本的同时,让各个顾客尽快收到货物成了现代交通运输物流中一个越来越重要的考虑因素。基于某快递公司的运输实例,本文提出了装卸一体化的车辆路径问题模型,最终优化目标是最小化车辆运输时间和货物到各个顾客的时间的加权和,并给出了一种基于插入法的新禁忌算法,实验结果表明新禁忌算法在显著提高传统禁忌算法计算时间的同时,还能得到理想的成本,并且对节约快递公司的运输成本方面有显著成效。     

岚山公司库场创新管理的探讨

港口库场是水运货物的主要集散场所，对缩短车船停留时间、加快货物周转、提高货运质量有重要作用。结合岚山公司港口库场实际，根据“降成本、深挖潜、促效益”的思想，通过实施科学计划、精细管理，合理调配，重点向库场管理要效益，逐步实现“货场最大效能促进港口最大效益”的卧标，将库场创新管理推向企业战略管理层面。     

推进甩挂运输发展的思路

甩挂运输是一种先进的运输方式,甩挂运输能够对大量散件货物的运输在较短的时间快速周转,实现货物堆放零库存,提高仓库利用率,减少货损货差、防污染、降低耗油量,达到环保的作用,能够运行网络化和实现智能信息平台的调度,提升科学管理水平.该文阐述甩挂运输优势、国内外甩挂运输的发展情况和存在问题,着重介绍福建省发展甩挂运输的思路和相关建议.     

基于RFID的快递物流配送系统设计

快递物流就是为了满足客户的需要,以最低的成本,最快的时间,通过运输、分拣等方式将客户的货物或物品从发件人所在地运达收件人的一种快速运输方式,是一种门到门的服务。通过对系统中的构成因素,各个环节进行分析研究,以达到最优化设计,最优控制和最优管理的目标。本文以四川地区为配送范围,运用射频识别技术(RFID)实现自动分拣,设计了一个高效率,低出错率,自动化的快递物流的配送系统。     

一种求解时变网络下多式联运最短路的算法

在运输过程中,往往不止有一种运输方式,可能同时有多种运输方式交叉,即可能多式联运的方式存在,不同的运输方式之间需要通过转运才可实现.同时,在运输过程中,成本、运输时间、风险等因素会随着时间的不同而变化.首先,将运输网络进行变形,然后给出了在时变网络条件下多式联运的最短路模型,设计了求解时变条件下多式联运的最短路的算法,利用此算法可以获得从起点到终点之间的最短路,并对算法的计算复杂性进行了分析.最后给出一个应用算例.     

组织运输的税收筹划

企业的购销过程中离不开货物的运输费用,采购材料需要发生运费,销售货物过程中也会产生运费,并且企业的运费收支又与税收有着密切的联系。为了提高企业的经济效益,企业应当进行合理的组织运输。合理的税收筹划又应当充分考虑企业所处的外部环境的变化,尤其是重视国家税收政策的变化。目前交通运输业已经全面实现营改增,所以下面将讨论营改增后,销售货物过程中运费增值税的税收筹划问题。     

面向双层自动分拣系统的包裹分拣优化模型与算法研究

近年来随着电子商务的快速发展,分拣订单呈现批量小、品种多、配送周期短、精度要求高等特征,这对分拣作业提出了更高的要求。为了缩短分拣时间、降低分拣成本、提高分拣效率,物流企业开始逐步使用双层分拣设备。本文采用了"成组分拣"方法以提升托盘利用率,"成组分拣"是指一种将分散的单件包裹按一定的规则组合在一起,成为一个规格化、标准化的大分拣单元进行分拣的方法。根据"成组分拣"的定义,本文研究了一个考虑成组分拣的双层分拣设备目的地指派问题,并设计了一种高效的变邻域禁忌搜索算法,该算法能在较短时间内对该问题进行求解,得到一个满意解。实验结果表明,采用"成组分拣"方法与考虑目的地指派问题可有效提高分拣设备的分拣效率。     

考虑多种安全库存策略的选址-库存问题研究

考虑多种安全设置策略的物流网络的选址-库存问题,不仅是选址、订货、运输和库存的集成优化,还需要考虑多种不同的安全库存设置和转运策略。因此,本文深入讨论了二级物流网络中的六种安全库存设置策略,构建了六种考虑不同安全库存设置的选址-库存模型。在考虑集中设置安全库存时,集中安全库存需要通过转载运输实现,因此需要将转载运输成本引入选址-库存模型之中,使新的选址-库存模型更加科学合理。另外,针对六种新的选址-库存模型,提出了基于个体成本差异分配的遗传算法,迭代搜索选址、分配、库存设置策略的优化组合。最后,通过数据实验验证了模型的有效性：（1）安全库存与转载运输之间存在此消彼长的背反关系;（2）安全库存设置和转载运输策略对总成本的影响取决于两种费率权重情况。本文的研究可以为二级物流网络的选址、订货和安全库存策略集成优化决策提供参考依据。     

Multiple In‐Cycle Transshipments with Positive Delivery Times

We study a centralized inventory sharing system of two retailers that are replenished periodically. Between two replenishments, a unit can be transshipped to a stocked‐out retailer from the other. It arrives a transshipment time later, during which the stocked‐out retailer incurs backorder cost. Without transshipment, backorder cost is incurred until the next replenishment. Since the transshipment time is shorter than the time between two replenishments, transshipments can reduce the backorder cost at the stocked‐out retailer and the holding costs at the other retailer. The system is directed by a centralized inventory manager, who minimizes the long‐run average cost consisting of replenishment, holding, backorder, and transshipment costs. The transshipment policy is characterized by hold‐back inventory levels, which are nonincreasing in the remaining time until the next replenishment. The transshipment policy differs from those in the literature because we allow for multiple transshipments between replenishments, positive transshipment times, and backorder costs. We also discuss the challenges associated with positive replenishment time and develop upper and lower bounds of average cost in this case. Bounds are numerically shown to have an average gap of 1.1%. A heuristic solution is based on the upper bound and differs from the optimal cost by at most this gap.     

Complexity analysis for maximum flow problems with arc reversals

We provide a comprehensive study on network flow problems with arc reversal capabilities. The problem is to identify the arcs to be reversed in order to achieve a maximum flow from source(s) to sink(s). The problem finds its applications in emergency transportation management, where the lanes of a road network could be reversed to enable flow in the opposite direction. We study several network flow problems with the arc reversal capability and discuss their complexity. More specifically, we discuss the polynomial time algorithms for the maximum dynamic flow problem with arc reversal capability having a single source and a single sink, and for the maximum (static) flow problem. The presented algorithms are based on graph transformations and reductions to polynomially solvable flow problems. In addition, we show that the quickest transshipment problem with arc reversal capability and the problem of minimizing the total cost resulting from arc switching costs are NP\mathcal{NP} -hard.     

两级供应链中供应中断情形下零售商转运策略

考虑由两个供应商和两个零售商组成的两级供应链系统,且两个供应商以一定概率发生供货中断,基于供应商供货发生中断的四种情形,分别对零售商实施相互转运策略、单向转运策略和不转运策略下建立最优订货决策模型。从理论上比较了三种策略下零售商期望利润和订货量高低,并分析相互转运和单向转运策略下零售商期望利润和订货量与转运价格、转运成本之间的关系,最后运用算例进行验证,同时分析了三种策略下,供应中断概率和其它主要参数的变化对零售商期望利润和最优订货量的影响。     

Retailer Transshipment versus Central Depot Allocation for Supply Network Design

We consider a supply chain structure with shipments from an external warehouse directly to retailers and compare two enhancement options: costly transshipment among retailers after demand has been realized vs. cost‐free allocation to the retailers from the development of a centralized depot. Stochastic programming models are developed for both the transshipment and allocation structures. We study the impact of cost parameters and demand coefficient of variation on both system structures. Our results show an increasing convex relationship between average costs and demand coefficient of variation, and furthermore that this increase is more pronounced for the allocation structure. We employ simulation and nonlinear search techniques to computationally compare the cost performance of allocation and transshipment structures under a wide range of system parameters such as demand uncertainty and correlation; lead times from the external warehouse to retailers, from warehouse to central depot, and from depot to retailers; and transshipment, holding, and penalty costs. The transshipment approach is found to outperform allocation for a broad range of parameter inputs including many situations for which transshipment is not an economically sound decision for a single period. The insights provided enable the manager to choose whether to invest in reducing lead times or demand uncertainty and assist in the selection of investments across identical and nonidentical retailers.     

降低供应链成本 提升市场竞争力

当B2C电子零售企业业务快速增长的同时,其面临的挑战也日益显著。这其中非常重要的一项就是供应链运营成本方面的考验,而运输成本和配送中心人工成本尤为重要。本文关注典型传统B2C电子零售企业的网络库存转运问题,以先进的工具来改善网络库存转运决策流程,加快对网络库存水平即时变化以及对市场需求变化的响应速度,降低供应链运营成本,保证其成本方面的优势提升市场竞争力。     

The mixed evacuation problem

A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transit times on its arcs. The quickest transshipment problem is one of the most fundamental problems in dynamic networks. In this problem, we are given sources and sinks. Then the goal of this problem is to find a minimum time limit such that we can send the right amount of flow from sources to sinks. In this paper, we introduce a variant of this problem called the mixed evacuation problem. This problem models an emergent situation in which people can evacuate on foot or by car. The goal is to organize such a mixed evacuation so that an efficient evacuation can be achieved. In this paper, we study this problem from the theoretical and practical viewpoints. In the first part, we prove the polynomial-time solvability of this problem in the case where the number of sources and sinks is not large, and also prove the polynomial-time solvability and computational hardness of its variants with integer constraints. In the second part, we apply our model to the case study of Minabe town in Wakayama prefecture, Japan.     

Inventory and transshipment decisions in the rationing game under capacity uncertainty

In this paper, we consider the inventory decisions of two retailers who are supplied by a single supplier with uncertain capacity. When capacity is allocated in proportion to the retailers׳ orders, the retailers compete for the capacity by inflating their orders (i.e., the rationing game). In addition, we allow the retailers to implement transshipment between them such that they cooperate by transshipping the surplus stock of one to another who is out of stock. Our analysis of Nash equilibrium orders shows that, while order inflation in the equilibrium orders persists in the rationing game with transshipment, it may not occur if the amount of capacity shortage is small and the transshipment prices are low. Thus, carefully chosen transshipment prices may alleviate order inflation behavior. We also characterize centralized orders that maximize the total profit of the retailers and compare them to equilibrium orders. In particular, we investigate coordinating transshipment prices that induce the retailers to choose centralized orders. Our numerical analysis shows that, even for two identical retailers, coordinating transshipment prices exist in a more limited range of parameter values in the rationing game than they do outside the rationing game due to capacity uncertainty and limitation.     

供应链中考虑下游转运的订货和定价决策研究

当供应提前期相对较长而且对未来需求难以进行准确预测的时候,转运策略便成为实现需求与供给匹配的强有力的协调策略。本文以医药供应链为背景,考虑由一个制造企业和两个批发企业组成的供应链系统,研究了在分散决策的情况下,使用转运补货机制后,批发企业的最优订货决策和制造企业的最优定价决策问题,并通过数值试验考察了各成员决策行为对供应链整体绩效的影响。