基于($D,U$)控制策略的港口群空箱存储与调运联合优化

针对区域港口群内陆公共腹地的空箱供需状况,构建多港口、多周期空箱存储与调运联合优化混合整数规划模型,利用马尔科夫决策过程与动态规划相结合的方法,在(D,U)库存控制策略下对港口群内各港口的空箱库存保有量区间进行动态优化,以此为基础对港口群公共腹地和各港口间的空箱调运方案进行优化,并以辽宁沿海港口群-----东北腹地为对象进行实证分析.实验结果表明,(D,U)控制策略下的空箱调运能够为船公司节省15.22%的总成本.选取公共腹地数量、公共腹地和港口空箱需求量、单位租箱成本以及单位库存成本进行灵敏度分析,进而验证(D,U)控制策略能够削弱船公司在外界环境发生变化时受到的影响.     

Pricing and balancing of the sea–cargo service chain with empty equipment repositioning

To sustain a business, firms have to reposition empty containers from a surplus port to a port with a shortage and incur repositioning costs if the realized demands are unbalanced in the sea–cargo service chain. In this paper, we study a sea cargo service chain with one carrier and two forwarders providing transportation service between two ports, and there are potential demands for transportation services in both directions. We built a mathematical model to study how the carrier and forwarders determine pricing and empty equipment repositioning (hereafter EER) decisions. We find that whether or not the carrier and forwarders use pricing policies to balance the cargo demands depends on the potential demand imbalance volume between two ports. We also investigate the EER sharing strategy on whether to share the EER cost or undertake it solely. It is found that there exists a threshold, and when the EER cost is beyond the threshold value, the carrier assumes all of the repositioning costs; otherwise, the forwarder assumes all of the repositioning costs. Lastly, we study a subsidy contract between both forwarders and expand to study an EER sharing mode between the carrier and both forwarders.     

基于遗传算法的海运集装箱空箱调运成本优化

根据港口集装箱调运的特点,对空箱调运的问题进行分析,考虑租箱成本、运输成本、装卸成本和调运约束等条件,以最小化调运成本为目标,建立在保证重箱运输前提下的空箱调运的非线性整数模型.文中使用简单遗传算法和加入遗传算子的遗传算法分别对模型实例进行求解,实验表明,当采用加入遗传算子的遗传算法时获得的结果比采用简单遗传算法的更好.     

Application of a mixed fuzzy decision making and optimization programming model to the empty container allocation

Containerization transportation has been growing fast in the past few decades. International trades have been growing fast since the globalization of world economies intensified in the early 1990s. However, these international trades are typically imbalanced in terms of the numbers of import and export containers. As a result, the relocation of empty containers has become one of the important problems faced by liner shipping companies. In this paper, we consider the empty container allocation problem where we need to determine the optimal volume of empty containers at a port and to reposition empty containers between ports to meet exporters’ demand over time. We formulate this empty container allocation problem as a two-stage model: in stage one, we propose a fuzzy backorder quantity inventory decision making model for determining the optimal quantity of empty container at a port; whereas in stage two, an optimization mathematical programming network model is proposed for determining the optimal number of empty containers to be allocated between ports. The parameters such as the cost of loading container, cost of unloading container, leasing cost of empty container, cost of storing container, supplies, demands and ship capacities for empty containers are considered in this model. By taking advantages of the fuzzy decision making and the network structure, we show how a mixed fuzzy decision making and optimization programming model can be applied to solve the empty container allocation problem. The utilization of the proposed model is demonstrated with a case of trans-Pacific liner route in the real world. Six major container ports on the trans-Pacific route are considered in the case study, including the Port of Kaohsiung, the Port of Hong Kong, the Port of Keelung, the Port of Kobe, the Port of Yokohama and the Port of Los Angles. The results show that the proposed mixed fuzzy decision making and optimization programming model can be used to solve the empty container allocation problem well.     

Maritime repositioning of empty containers under uncertain port disruptions

This paper addresses the problem of repositioning empty containers in maritime networks under possible port disruptions. Since drastically different futures may occur, the decision making process for dealing with this problem cannot ignore the uncertain nature of its parameters. In this paper, we consider the uncertainty of relevant problem data by a stochastic programming approach, in which different scenarios are included in a multi-scenario optimization model and linked by non-anticipativity conditions. Numerical experiments show that the multi-scenario solutions provide a hedge against uncertainty when compared to deterministic decisions and exhibit some forms of robustness, which mitigate the risks of not meeting empty container demand.     

物流包装租赁系统配送库存路径模型与算法

发展物流包装租赁共享系统是解决落后的一次性包装使用方式的有效手段。为优化物流包装租赁系统中的空包装配送与库存控制这一频繁决策问题,将租赁客户点的需求和物流包装租赁系统的服务中心的库存能力、库存费用、车辆容量、单位运费等因素引入模型,建立了总成本费用最小的物流包装租赁共享系统的空包装配送库存路径集成优化模型。针对稍小和稍大规模算例,对利用CPLEX优化软件和带精英保留的改进遗传算法进行了求解比较分析,结果表明：改进遗传算法对稍大规模算例求解的结果虽然稍差,但求解时间大大缩短,这说明了启发式算法对大规模的实际问题是有效的。该模型和算法可为物流包装租赁企业的空包装配送和库存控制的集成优化决策提供参考。     

Contract analysis: A performance measures and profit evaluation within two-echelon supply chains

Coordination is regarded as key in managing dependencies between distinctive members of a supply chain through the benefits of coordination mechanisms. Such coordination mechanisms are contracts, implemented to increase total supply chain profit, reduce costs and share risk among supply chain members. However, by contract implementation the retailer is constrained in his purchase by bearing the entire risk of holding the inventory (wholesale price contract) or by limited risk allocated to the supplier (buyback, revenue sharing and quantity flexibility contracts). By implementing an advanced purchase system the risk of inventory is fairly divided between the supplier and the retailer. In order to observe inventory implications on the supply chain bottom line, this article is directed towards the evaluation of performance measures and supply chain profit behavior under buyback, revenue sharing, quantity flexibility and advanced purchase discount contracts versus no coordination and wholesale price systems.     

Satisfying market demands with delivery obligations or delivery charges

Consider a firm that receives deterministic, time-varying demands for its product. The firm has the flexibility to choose its customer base and receive market-specific revenues for its product. In addition to market revenue and market demand, the parameters of a negotiated contract can also play a role in market selection and fulfillment decisions. Two such parameters are (1) delivery obligation penalties and (2) delivery charges. In this paper, we determine optimal solution approaches for problem settings when either of these contract parameters is present. Our tailored solution techniques can solve each problem in a fraction of the time required by a state-of-the-art commercial optimization solver.     

需求依赖减排水平和价格的供应链决策与协调机制

针对由一个低碳产品制造商与一个零售商组成的供应链, 考虑需求同时受减排水平和销售价格的影响, 分别研究寄售契约、收益共享契约以及收益共享与减排成本共担3 种契约下供应链企业的优化决策, 并进一步探讨当需求的确定部分为和式、随机部分服从均匀分布时的供应链系统的最优决策. 从理论上证明了制造商与零售商之间的合作利于促进减排水平的提升, 也利于供应链系统期望总利润的增加. 最后, 探讨了不同参数对协调供应链绩效的影响.

     

A local search heuristic for the pre- and end-haulage of intermodal container terminals

Pre- and end-haulage of intermodal container terminals involves the pickup or delivery of containers at customer locations. The attractiveness of intermodal transport can be increased by organizing the road segment in the intermodal transport chain more efficiently. In this paper the drayage of containers in the service area of an intermodal terminal is modelled as a full truckload pickup and delivery problem with time windows (FTPDPTW). A two-phase insertion heuristic is proposed to construct an initial solution. This solution is improved with a local search heuristic based on three neighbourhoods. Numerical experiments are described to demonstrate the mechanisms of the heuristics.     

产量和需求随机下基于收益共享契约的供应链决策

针对产量和需求都随机的供应链, 在条件风险值(CVaR) 的度量准则下, 建立具有风险规避型零售商的供应链最优决策模型, 探讨收益共享契约下供应链协调的条件, 并进行了数值分析. 研究结果表明, 零售商的风险规避以及产量的不确定性将降低最优订购量及供应链效益; 收益共享契约可以优化产量和需求随机条件下的供应链运作效率, 并在一定条件下使供应链达到协调.

     

Coordinating preventive lateral transshipment between two locations

We analyze preventive transshipment between two locations in anticipation of the mismatch between demands and inventories, and the effects of the preventive transshipment on ordering quantities. The time horizon for preventive transshipment includes two stages: the ordering stage and the shipping stage. At the ordering stage, the two locations order products from their supplier. During the replenishment lead-time, some demand signals (e.g., the realized demand for a complementary product) may be observed. Therefore, the locations may update their demand distributions and preventively transship to each other at the shipping stage. When the two locations make their ordering and transshipping decisions individually to maximize their own profits, there are incentive problems that prevent coordination. These problems arise even between the locations that pay each other for transshipped units. We examine two commonly used linear transfer price contracts: the ex ante transfer price contract and the ex post transfer price contract. However, neither of these contracts coordinates the transshipment quantities between the two locations. We then present a bidirectional revenue sharing contract that can coordinate the transshipment quantities. We find the conditions under which this proposed contract coordinates the ordering quantities. Finally, we investigate how the transportation cost and the amount of information updating affect the ordering quantities with the coordinating bidirectional revenue sharing contract.     

Contract efficiency for a decentralized supply chain in the presence of quality improvement

In this paper, we study a joint pricing and product quality decision problem in a decentralized supply chain consisting of one manufacturer and one retailer. Although the manufacturer decides the product quality with an associated cost, the retailer decides the retail price. We aim to study and compare different contract formats for this decentralized supply chain. There is a trade‐off in the choice of contracts: simpler format contract (with a few parameters) is less complicated, but the contract efficiency is low. We start with the simplest one‐parameter contract: a wholesale price contract that serves as the benchmark. We then study how contract efficiency can be improved by adding one more parameter. Specifically, we consider three two‐parameter contracts that are commonly used in reality: two‐part tariff contract, revenue‐sharing contract, and effort cost sharing contract. We find that the contract efficiency is improved under all the three contracts, but in different ways: the improvement in contract efficiency under each of them dominates the other two when manufacturer's quality improvement effectiveness is relatively low, moderate, and high, respectively. Furthermore, through numerical examples, we find that under some cases, a choice from these three two‐parameter contracts can achieve a close‐to‐perfect efficiency (>85%). Finally, we investigate whether a combination of the three two‐parameter contracts can achieve coordination. Interestingly, we find that only the combination of effort cost sharing contract and revenue‐sharing contract can achieve coordination, whereas combinations of either of them and two‐part tariff contract cannot.     

考虑风险规避与质量和服务水平的VMI供应链期权协调策略

针对一个考虑风险规避供应商与质量和服务水平的二级VMI供应链,应用条件风险价值(CVaR)准则刻画供应商的风险规避行为,提出由期权和成本分担构成的组合契约,构建以零售商为主导的Stackelberg博弈模型,探讨供应链协调策略以及风险规避对供应链协调和利润分配的影响.研究表明,供应商的最优生产量随着其风险规避程度的增加而减小,但最优质量和服务水平与风险规避程度无关;当且仅当供应商风险规避程度较低时供应链才能实现协调,且供应商风险规避程度是影响供应链契约设计和利润分配的关键因素.     

Downside-risk控制下的供应链收益共享契约设计研究

运用Downside-risk约束,对一个两阶供应链模型中风险规避型零售商与其上游风险中性供应商之间的协调进行契约设计和建模,在供应链收益共享契约下风险约束得到满足.并且供应商和零售商的利润均得到了提高.同时,供应链收益共享契约得到有效设计时,风险中性方可为风险规避方提供相应的风险保护,满足其风险约束,可产生更多的利润,以更好地协调供应链.算例分析验证了该结论的有效性.     

经济效益与水质提升双视角下南水北调水资源供应链契约协调

南水北调工程是国家水网的重要组成部分,为进一步发挥南水北调工程水资源优化配置能力,确保优质南水供给,推动后续运营管理工作有序开展,助力国家水网建设,结合博弈论与供应链理论,从考虑经济效益和水质提升双目标视角,探讨南水北调水资源供应链协调问题.基于对南水北调水资源供应系统的概化及相关假设,建立水资源供应链的市场需求函数、水质效用函数和水质提升成本函数,分别构建包括集中决策、批发价格契约和收益共享-水质提升成本共担契约下的水资源供应链多目标模型并探讨相应的协调策略.最后通过数值分析对结论进行验证.研究表明,水质效用与经济效益之间存在冲突,批发价格契约无法实现供应链的协调,而收益共享-水质提升成本共担契约可以实现水质效用目标的协调,以及经济目标的帕累托改进.     

基于碳配额政策的两级低碳供应链博弈与优化

通过构建供应商和制造商两级低碳供应链Stackelberg博弈模型,得到博弈均衡解和收益共享契约参数,比较分散决策、集中决策和收益共享契约下实现低碳供应链的经济效应,并通过算例分析了是否合作减排以及合作减排对供应链成员产量、碳减排量、利润的影响和收益共享契约参数对供应链成员利润的影响,为供应链上下游企业开展碳减排合作提供了理论依据和政策建议.     

宁波港中距离无水港选址问题研究

随着港口规模等级的竞争延伸到腹地竞争以及内陆运输领域的不断发展,集装箱多式联运和无水港的发展越来越受到关注。针对无水港选址问题,提出了一种结合模拟退火算法的混合遗传算法进行整体求解,并与IBM ILOG CPLEX12.2的求解结果进行比较。主要在集装箱多式联运的基础上研究了无水港选址,同时考虑了建立无水港所形成的规模经济效应,在模型中加入了成本折扣系数。虽然以宁波港的无水港选址为例,但此选址方法也适用于其他港口的无水港选址。     

Container storage space assignment problem in two terminals with the consideration of yard sharing

Facing the shortage of storage space of container terminal yard, a yard sharing strategy that uses dry port's surplus storage space to ease container congestion is proposed. This novel strategy can address the container storage space assignment problem for inbound containers. The problem is studied based on the storage yard of the combined container terminal and dry port. First, a multiple-objective mixed integer programming model that considers yard sharing strategy with the objectives of minimizing total travel distance, minimizing imbalance in number of containers, maximizing shared storage space of the dry port is formulated to obtain optimal solutions. Second, a non-dominated sorting genetic algorithm II (NSGA-II) is proposed. Next, the performance of the algorithm is verified by a set of instances. Numerical experiments are conducted to elucidate the problem with yard sharing strategy intuitively. Furthermore, the performance of the model in four aspects proclaims the advantages of yard sharing strategy and certifies the comprehensiveness. Finally, sensitivity analysis is conducted by two aspects which are weight coefficient and feasible distance to verify the efficiency of the proposed method.     

带有风险规避型销售商的供需链协调

以一个两阶段的供需链系统为背景，针对供需链上决策激励不一致和风险规避效应导致供需链低效的问题，研究了在实践中广泛应用的利益共享合同和批量折扣合同对供需链协调性的影响．证明了两种合同均可克服双重边际效应和风险规避效应，使得供需链协调．并给出了合同参数的设计方案，同时指出在实施上，利益共享合同需强制执行，批量折扣合同自动执行．