A two‐echelon inventory‐location problem with service considerations

We study the problem of designing a two‐echelon spare parts inventory system consisting of a central plant and a number of service centers each serving a set of customers with stochastic demand. Processing and storage capacities at both levels of facilities are limited. The manufacturing process is modeled as a queuing system at the plant. The goal is to optimize the base‐stock levels at both echelons, the location of service centers, and the allocation of customers to centers simultaneously, subject to service constraints. A mixed integer nonlinear programming model (MINLP) is formulated to minimize the total expected cost of the system. The problem is NP‐hard and a Lagrangian heuristic is proposed. We present computational results and discuss the trade‐off between cost and service. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

多架无人机协同作战的路径规划

提出了一种协调多架无人机的编队同时到达目标的航路规划方法.首先根据敌方防御区域内雷达、导弹等威胁阵地的具体分布情况,采用划分Voronoi多边形的方法制定初始航路,然后通过叠加定长线段到初始航路上对初始航路进行离散化,最后采用动态链类比法调整航路并对航路进行光顺优化处理,使航路安全可飞.并用数字仿真技术对该方法进行了验证,结果表明该方法是可行的.     

库存控制条件下弹药供应链稳定性研究

由于弹药供应链系统中存在牛鞭效应问题,为了减少牛鞭效应对弹药供应系统的影响,研究系统的稳定性,建立了一阶弹药供应链系统。分析了弹药供应链系统的构成,对系统进行了数学建模分析与仿真验证分析。分析得出,决策参数调整系数β对弹药供应链系统稳定性的影响明显,部队需求量变化及订货量决策参数安全系数α影响较弱。并得出系统稳定时或系统出现震荡、混沌现象时调整系数β的取值范围。     

空战视景仿真系统通用框架研究

依据一个空战视景仿真系统的开发,系统分析了视景仿真系统的一般性规律和其管理框架。通过分析空战视景仿真系统的硬件、软件结构,着重提炼出不同的视景仿真系统的共性与特殊性。在软件设计过程中,对数据处理、实体管理和事件响应的设计,重视了设计模式的应用,将仿真系统的通用性、可拓展性与软件工程理论相结合,构建了一个可通用的,具有拓展性的视景仿真软件平台。视景仿真系统通用框架的研究,为设计更加灵活,更加适用的视景系统提供了理论基础;对于以后的视景仿真系统的设计,具有一定的参考价值。     

Disruption‐management strategies for short life‐cycle products

Supplier diversification, contingent sourcing, and demand switching (whereby a firm shifts customers to a different product if their preferred product is unavailable), are key building blocks of a disruption‐management strategy for firms that sell multiple products over a single season. In this article, we evaluate 12 possible disruption‐management strategies (combinations of the basic building‐block tactics) in the context of a two‐product newsvendor. We investigate the influence of nine attributes of the firm, its supplier(s), and its products on the firs preference for the various strategies. These attributes include supplier reliability, supplier failure correlation, payment responsibility in the event of a supply failure, product contribution margin, product substitutability, demand uncertainties and correlation, and the decision makes risk aversion. Our results show that contingent sourcing is preferred to supplier diversification as the supply risk (failure probability) increases, but diversification is preferred to contingent sourcing as the demand risk (demand uncertainty) increases. We find that demand switching is not effective at managing supply risk if the products are sourced from the same set of suppliers. Demand switching is effective at managing demand risk and so can be preferred to the other tactics if supply risk is low. Risk aversion makes contingent sourcing preferable over a wider set of supply and demand‐risk combinations. We also find a two‐tactic strategy provides almost the same benefit as a three‐tactic strategy for most reasonable supply and demand‐risk combinations. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009     

战役物资供应链定性仿真研究

运用定性建模与仿真的方法研究战役物资供应链的整体供应能力,能从整体性角度出发,全局遍历战役物资供应链的不利影响因素。简要介绍了SDG(Signed Directed Graph)定性仿真工具的结构和功能;建立了战役物资供应链整体功能定性仿真模型;根据案例描述,把定量描述转化成定性值,设置定性仿真初始值,进行定性仿真实验。仿真结果为:影响战役物资供应链整体供应能力的主要不利因素为"敌火力打击我战役供应指挥机构",可找到其产生的推理路径,改变定性初始值的设置,控制不利影响因素出现的次数。