An approximate dynamic programing approach to the development of heuristics for the scheduling of impatient jobs in a clearing system

A single server is faced with a collection of jobs of varying duration and urgency. Each job has a random lifetime during which it is available for nonpreemptive service. Should a job's lifetime expire before its service begins then it is lost from the system unserved. The goal is to schedule the jobs for service to maximize the expected number served to completion. Two heuristics have been proposed in the literature. One (labeled π^S) operates a static priority among the job classes and works well in a “no premature job loss” limit, whereas the second (π^M) is a myopic heuristic which works well when lifetimes are short. Both can exhibit poor performance for problems at some distance from the regimes for which they were designed. We develop a robustly good heuristic by an approximative approach to the application of a policy improvement step to the asymptotically optimal heuristic π^S, in which we use a fluid model to obtain an approximation for the value function of π^S. The performance of the proposed heuristic is investigated in an extensive numerical study. © 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010     

新编制体制下武警部队装备任务需求

为加快建设现代化武警部队,解决配属装备与日益增长的任务需求之间的矛盾,论文以武警部队指挥体系变更、警种部队调整的现实背景,围绕武警部队遂行任务情况,整理分析出新编各警种对装备的任务需求,为推动武警部队装备体系发展提供理论参考。     

Scheduling parallel machines with inclusive processing set restrictions

We consider the problem of assigning a set of jobs to different parallel machines of the same processing speed, where each job is compatible to only a subset of those machines. The machines can be linearly ordered such that a higher‐indexed machine can process all those jobs that a lower‐indexed machine can process. The objective is to minimize the makespan of the schedule. This problem is motivated by industrial applications such as cargo handling by cranes with nonidentical weight capacities, computer processor scheduling with memory constraints, and grades of service provision by parallel servers. We develop an efficient algorithm for this problem with a worst‐case performance ratio of + ε, where ε is a positive constant which may be set arbitrarily close to zero. We also present a polynomial time approximation scheme for this problem, which answers an open question in the literature. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

装备维修管理系统的设计与实现

装备维修管理系统是一种新型维修管理模式,为解决现代装备协同维修过程中资源优化调度和分配的各类问题,从装备维修保障系统的需求分析入手,讨论了基于改进遗传算法的维修资源配置算法,并采用建模与仿真技术,设计实现了装备维修管理系统。     

Lot streaming with supplier–manufacturer coordination

Lot splitting refers to breaking a production lot into smaller sublots during production. Coordinating lot splitting decisions across multiple stages of a production process is a challenging task. Traditional lot splitting and lot streaming models implicitly assume that the entire system is operated and owned by the same firm, or there exists a coordinator who controls the operation of all machines in the system. In this paper, we consider the situation where the machines in a multiple‐stage production process are owned and managed by different companies. Every item in a given production lot has to go through the processing by the supplier's machine, followed by the manufacturer's machine, and so on. We develop and analyze coordination mechanisms that enable different parties in the supply chain to coordinate their lot splitting decisions so as to achieve a systemwide optimum. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

Reformulating linear programs with transportation constraints—With applications to workforce scheduling

We study linear programming models that contain transportation constraints in their formulation. Typically, these models have a multistage nature and the transportation constraints together with the associated flow variables are used to achieve consistency between consecutive stages. We describe how to reformulate these models by projecting out the flow variables. The reformulation can be more desirable since it has fewer variables and can be solved faster. We apply these ideas to reformulate two well‐known workforce staffing and scheduling problems: the shift scheduling problem and the tour scheduling problem. We also present computational results. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

基于GO法的多阶段共因失效任务系统可靠性评估

为了解决部件阶段依赖性与共因失效给系统可靠性分析带来的复杂性,针对多阶段共因失效任务系统,结合GO法易于处理有时序、含共因失效系统可靠性分析的特点,首先,将前一阶段的输出信号作为后一阶段的输入信号,建模时首尾连接各阶段模型,建立整个任务系统的隐性GO模型;其次,在进行各信号流状态组合运算时,融入阶段代数处理部件的阶段依赖性;再次,用隐性共因失效分析,将共因失效对系统的影响在状态组合的定量分析中表达出来,得到所需系统可靠性指标;最后,与基于二元决策图的算法进行对比验证。结果表明:GO法可以简捷、准确地处理多阶段共因失效任务系统可靠性评估问题。     

基于运动学模型的灵巧成像卫星观测摆角算法

针对灵巧成像卫星对地面目标观测摆角的计算问题,考虑地球自转和卫星在轨运动等约束,利用空间坐标变换建立了基于椭球体的空间运动学模型.在此模型的基础上,给出了任意时刻卫星对目标观测摆角的计算方法.仿真结果验证了方法的正确性.任意时刻观测摆角的获取为灵巧成像卫星任务调度提供支持.     

基于协同学的编队协同空战任务决策

基于协同学理论给出了编队协同空战系统的协同学框架;提出了编队协同作战方案的五元组定义,明确了影响系统进程的序参量;基于系统有序度与协同度的概念,构建了协同效能优化模型;以任务冲突检测与消解为依据给出了任务决策的约束条件;最后以二进制粒子群优化算法对此约束优化问题进行了求解.仿真结果表明,以协同学理论描述编队协同任务决策问题是可行的,构建的协同效能模型与任务决策方法在处理编队时序任务决策问题时是有效的.     

用于任务规划的航母编队防空威胁建模

建立正确的航母编队防空威胁模型是反航母任务规划成功的前提,在分析网络化条件下航母编队综合防空反导体系作战特点基础上,综合考虑反舰导弹性能、防空雷达网和编队防空火力威胁等因素,利用加权指数方法建立了网络化条件下航母编队综合防空网络威胁模型。仿真结果表明该模型能够体现航母网络化防空体系的真实情况,可以用于反航母任务规划。