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251.
介绍了一种面向移动Agent的并行计算模型,给出了采用十标度策略解决任务排序,采用满射策略解决任务映射的算法。该模型允许多个计算任务在异构主机构成的分布式环境下同时进行计算,并且通过算法优化,降低移动Agent之间的通信成本,减少网络流量。 相似文献
252.
针对SMP机群,探讨了分别利用单机优化、OpenMP与MPI从指令级、共享存储级与分布主存级三个层次上改善矩阵并行乘Fox算法性能的方法。并通过调用数学函数库与混合编程的方式,在深腾6800上进行了实验,取得了相当满意的数值效果。 相似文献
253.
254.
基于遗传算法的弹炮混编防空群火力分配 总被引:2,自引:0,他引:2
近期局部战争中的防空作战经验表明:实施弹炮混编可以大大提高防空武器系统的作战效能,而如何实施有效的火力分配又是其中的一个重要环节.针对陆军弹炮混编防空群射击指挥中的火力分配问题,简要分析了防空导弹和高炮武器系统射击的不同特点,提出了弹炮混编防空群的火力分配方法,并建立了优化火力分配方案的数学模型.在此基础上,采用遗传算法对此模型求解.结果表明,遗传算法为弹炮混编防空群的火力优化分配问题提供了一条有效途径. 相似文献
255.
While there has been significant previous literature on inventory transshipment, most research has focused on the dealers' demand filling decision (when to fill transshipment requests from other dealers), ignoring the requesting decision (when to send transshipment requests to other dealers). In this paper we develop optimal inventory transshipment policies that incorporate both types of decisions. We consider a decentralized system in which the dealers are independent of the manufacturer and of each other. We first study a network consisting of a very large number of dealers. We prove that the optimal inventory and transshipment decisions for an individual dealer are controlled by threshold rationing and requesting levels. Then, in order to study the impact of transshipment among independent dealers in a smaller dealer network, we consider a decentralized two‐dealer network and use a game theoretic approach to characterize the equilibrium inventory strategies of the individual dealers. An extensive numerical study highlights the impact of the requesting decision on the dealers' equilibrium behavior in a decentralized setting. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
256.
We study optimal age‐replacement policies for machines in series with non‐instantaneous repair times by formulating two nonlinear programs: one that minimizes total cost‐rate subject to a steady‐state throughput requirement and another that maximizes steady‐state throughput subject to a cost‐rate budget constraint. Under reasonable assumptions, the single‐machine cost‐optimal and throughput‐optimal solutions are unique and orderable, and the multi‐machine optimal solutions have appealing structure. Furthermore, we establish equivalence between the two formulations and provide an illustrative numerical example. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
257.
首先用矩量法精确分析了考虑互耦影响时天线阵元的电流分布,给出了计算电流的解析式,并仿真计算了单元直线阵的电流分布。然后以等效网络法为基础研究互耦影响存在时修正MUSIC算法的DOA估计性能,仿真实验表明在互耦影响存在时MUSIC算法失效,而修正MUSIC算法仍然具有良好的DOA估计性能。 相似文献
258.
为解决传统舰载C4I威胁判断模型的不足,寻求适应信息化作战要求的舰载C4I威胁判断模型,将神经网络引入舰载C4I系统,提出了基于BP神经网络的威胁判断模型,并对BP算法进行了改进;通过Matlab仿真计算,结果表明该方法计算速度快、精度高. 相似文献
259.
Ji Hwan Cha 《海军后勤学研究》2006,53(3):226-234
Burn‐in procedure is a manufacturing technique that is intended to eliminate early failures of system or product. Burning‐in a component or system means to subject it to a period of use prior to being used in field. Generally, burn‐in is considered expensive and so the length of burn‐in is typically limited. Thus, burn‐in is most often accomplished in an accelerated environment in order to shorten the burn‐in process. A new failure rate model for an accelerated burn‐in procedure, which incorporates the accelerated ageing process induced by the accelerated environmental stress, is proposed. Under a more general assumption on the shape of failure rate function of products, which includes the traditional bathtub‐shaped failure rate function as a special case, upper bounds for optimal burn‐in time will be derived. A numerical example will also be given for illustration. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
260.
We consider the problem of scheduling orders on identical machines in parallel. Each order consists of one or more individual jobs. A job that belongs to an order can be processed by any one of the machines. Multiple machines can process the jobs of an order concurrently. No setup is required if a machine switches over from one job to another. Each order is released at time zero and has a positive weight. Preemptions are not allowed. The completion time of an order is the time at which all jobs of that order have been completed. The objective is to minimize the total weighted completion time of the orders. The problem is NP‐hard for any fixed number (≥2) of machines. Because of this, we focus our attention on two classes of heuristics, which we refer to as sequential two‐phase heuristics and dynamic two‐phase heuristics. We perform a worst case analysis as well as an empirical analysis of nine heuristics. Our analyses enable us to rank these heuristics according to their effectiveness, taking solution quality as well as running time into account. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献