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81.
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如何充分发挥小型通信干扰装备的作战效能是指挥员面临的棘手问题。本文将战术指标——干扰后的通信畅通区覆盖程度作为评估通信干扰装备分配优劣的指标,分别建立了单机和多部干扰时的通信干扰有效压制区和通信畅通区边界的计算模型,并给出了通信干扰有效压制区和通信畅通区面积的计算方法。构建了基于机会约束规划的空域频域通信干扰任务分配模型,并设计了混合蚁群算法和遗传算法的模型求解算法。最后进行了仿真实验,验证分析了模型和算法的合理性。研究成果为通信对抗战术计算和作战运用研究拓展了思路。 相似文献
83.
多层弹道导弹防御系统在助推段、飞行中段或再入段不同阶段实施拦截,可有效提高系统拦截概率,不同拦截阶段存在拦截弹最优配比问题。为了解决拦截弹道导弹过程中的最优分层配置的问题,本文分别以单层、双层、三层这三种拦截系统为例,通过公式演算和计算机仿真,得出了分段拦截弹道导弹时、不同拦截阶段的拦截弹之间的数量比与整体拦截成功率之间的关系;并提出了整体拦截成功率的概念。经仿真表明,在整体拦截成功率给定的情况下,使用本文所得出的不同拦截段之间所需拦截弹数目之间的最优比,可以最大限度地降低弹道导弹的拦截成本。 相似文献
84.
An inventory system that consists of a depot (central warehouse) and retailers (regional warehouses) is considered. The system is replenished regularly on a fixed cycle by an outside supplier. Most of the stock is direct shipped to the retailer locations but some stock is sent to the central warehouse. At the beginning of any one of the periods during the cycle, the central stock can then be completely allocated out to the retailers. In this paper we propose a heuristic method to dynamically (as retailer inventory levels change with time) determine the appropriate period in which to do the allocation. As the optimal method is not tractable, the heuristic's performance is compared against two other approaches. One presets the allocation period, while the other provides a lower bound on the expected shortages of the optimal solution, obtained by assuming that we know ahead of time all of the demands, period by period, in the cycle. The results from extensive simulation experiments show that the dynamic heuristic significantly outperforms the “preset” approach and its performance is reasonably close to the lower bound. Moreover, the logic of the heuristic is appealing and the calculations, associated with using it, are easy to carry out. Sensitivities to various system parameters (such as the safety factor, coefficient of variation of demand, number of regional warehouses, external lead time, and the cycle length) are presented. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005. 相似文献
85.
机械系统可靠性设计若干问题探讨 总被引:1,自引:0,他引:1
机械系统的可靠性设计是当前可靠性工程界面临的热点和难点问题之一,从分析机械系统可靠性设计的特点和难点入手,探讨了机械系统可靠性建模、分配、预计等机械系统可靠性设计中急需解决的关键问题。 相似文献
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87.
In this paper we study a capacity allocation problem for two firms, each of which has a local store and an online store. Customers may shift among the stores upon encountering a stockout. One question facing each firm is how to allocate its finite capacity (i.e., inventory) between its local and online stores. One firm's allocation affects the decision of the rival, thereby creating a strategic interaction. We consider two scenarios of a single‐product single‐period model and derive corresponding existence and stability conditions for a Nash equilibrium. We then conduct sensitivity analysis of the equilibrium solution with respect to price and cost parameters. We also prove the existence of a Nash equilibrium for a generalized model in which each firm has multiple local stores and a single online store. Finally, we extend the results to a multi‐period model in which each firm decides its total capacity and allocates this capacity between its local and online stores. A myopic solution is derived and shown to be a Nash equilibrium solution of a corresponding “sequential game.” © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
88.
Minimizing the makespan in open‐shop scheduling problems with a convex resource consumption function
We consider open‐shop scheduling problems where operation‐processing times are a convex decreasing function of a common limited nonrenewable resource. The scheduler's objective is to determine the optimal job sequence on each machine and the optimal resource allocation for each operation in order to minimize the makespan. We prove that this problem is NP‐hard, but for the special case of the two‐machine problem we provide an efficient optimization algorithm. We also provide a fully polynomial approximation scheme for solving the preemptive case. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006 相似文献
89.
在资源有限的情况下,综合考虑某一区域不同机场之间的相互关系,从整体的角度合理分配排弹抢修资源,可以大幅提升区域内军队机场阵地的战场排弹抢修能力。本文通过建立数学模型,从整体的角度出发,分析区域内各机场的排弹抢修资源分配问题:首先,针对不可预见作战带来的新挑战,提出了新的机场排弹抢修作业流程,引出排弹抢修力量分配所面临的几个现实问题;其次,为解决提出的问题,建立计算排弹抢修时间的数学模型;最后,利用建立的模型依次对上述问题进行分析,并给出排弹抢修资源编配与力量建设的建议。本研究认为,军事机场排弹抢修力量应根据机场特点,合理分配排弹抢修资源;要以机场排弹抢修力量为主导,以外部支援力量为辅助,提升机场自身排弹抢修能力;可通过建设排弹抢修物资仓库和设置排弹抢修支援小组,提升多机场联动的排弹抢修能力。 相似文献
90.
针对并行面向对象数据库的特点,结合异步并行查询执行策略,提出了一种基于对象类的混合式数据放置策略,它包括两个部分:混合式数据划分策略和基于对象类的数据分配策略 相似文献