基于年龄更换策略的威布尔分布备件需求计算方法

备件需求量预测在装备保障工作中发挥着重要作用。预防性维修可以消除装备潜在的故障或避免装备发生故障后所导致的严重后果,从而使装备始终处于期望状态。预防性维修策略下备件需求量建模能够以可预见的可靠性数据为基础进行,其关键问题是最佳更换间隔时间的确定。针对威布尔分布装备备件,采用年龄更换策略,确定最佳更换间隔时间,并在此基础上导出威布尔型备件需求计算模型,为备件需求量的预测提供了一种简单有效的方法。     

Technical note: Some structural results on acyclic supply chains

We consider acyclic supply chains under the full backorder assumption and reveal several simple yet unique properties. Most interestingly, we identify conditions for the best dedicated stocking policy to outperform the best shared stocking policy, and for an acyclic supply chain to be decomposable into a simpler network (e.g., tree). We specify ways to decompose them. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

The transshipment fund mechanism: Coordinating the decentralized multilocation transshipment problem

The multilocation replenishment and transshipment problem is concerned with several retailers facing random demand for the same item at distinct markets, that may use transshipments to eliminate excess inventory/shortages after demand realization. When the system is decentralized so that each retailer operates to maximize their own profit, there are incentive problems that prevent coordination. These problems arise even with two retailers who may pay each other for transshipped units. We propose a new mechanism based on a transshipment fund, which is the first to coordinate the system, in a fully noncooperative setting, for all instances of two retailers as well as all instances of any number of retailers. Moreover, our mechanism strongly coordinates the system, i.e., achieves coordination as the unique equilibrium. The computation and information requirements of this mechanism are realistic and relatively modest. We also present necessary and sufficient conditions for coordination and prove they are always satisfied with our mechanism. Numerical examples illustrate some of the properties underlying this mechanism for two retailers. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

高层民用建筑电气防火设计

针对高层民用建筑电气防火设计问题,结合现行国家标准的规定进行了探讨,提出了消防电源及其配电、应急照明等设计原则。     

基于更新过程的多阶段备件需求模型

正态分布、威布尔分布是常用的备件寿命模型,但是正态分布和威布尔分布的记忆性会导致多阶段需求量预测的相关性.利用更新过程理论,将叠加的更新过程分解和拼接,建立单阶段多项备件需求模型;通过将年龄转移到下个阶段,建立了多阶段不可修备件需求模型;采用加权平均法对多阶段需求模型进行了修正.仿真表明,这种模型能有效预测多阶段需求的波动.     

备件需求过程的MAP数据拟合算法研究

为了将备件需求过程表示为马尔可夫到达过程(Markovian arrival process, MAP)形式,设计了备件需求到达流的MAP拟合算法.首先,采用EM算法将备件需求到达间隔时间拟合成Hyper-Erlang分布形式,然后利用MAP性质和Bayes公式推导出生成元矩阵的计算公式;随后设计了一个完整的数据拟合流程,并通过实例对算法的效果和效率与已有研究进行了对比.结果表明,该算法在确保拟合效果的同时,能够有效提升拟合效率.     

基于多阶段博弈模拟的作战飞机零部件备用分析

从决策优化的角度出发,提出了一种利用多阶段博弈模拟来分析和解算作战飞机零部件备用的方法.该方法首先分析了多阶段博弈模拟在作战飞机零部件备用的应用,给出了最优化问题的总的目标函数一般形式.然后转换和简化所得到的最优化问题目标函数形式,从而有利于零部件备用的最优化解算.最后,给出了多阶段博弈模拟分析算法的主要步骤.仿真结果表明,这种方法解决了零部件使用模型问题求解的不精确的分析方法.将零部件使用周期作战飞机零部件备用看成一个整体来分析,符合未来网络中心战作战飞机零部件使用备份追求整体效能最大的思想.     

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     

基于仿真的飞机战损部位及备件需求确定

飞机战斗损伤部位及战时备件需求的确定对做好战时维修保障工作具有重要意义.提出了作战飞机的战斗损伤部位的确定方法,建立了飞机部件的当量模型和飞机受导弹攻击的仿真模型,确定了飞机的战伤分布规律.在确定飞机战伤分布规律的基础上,建立了飞机战伤备件和故障备件需求模型,为作战飞机的战伤研究及航材储备作了有益的探讨.     

电磁发射用脉冲功率电源放电建模分析

为高效研究电磁发射用脉冲功率电源放电性能,为电磁发射提供技术支持,降低研发成本,电磁发射过程的相关建模与仿真工作需要重点研究。对弹丸在轨道中实际运动物理过程建立数学模型,对脉冲功率电源建立电路模型,采用联合两种模型的方法对脉冲功率电源放电系统进行研究,提出一种基于发射过程多物理现象的脉冲功率电源放电系统仿真模型。通过实验验证了提出方法的有效性,为后续脉冲功率电源放电研究提供了依据。