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261.
We revisit the causal relationship between military spending and unemployment in the G7 countries applying a bootstrap panel causality analysis that accounts for both cross-sectional dependence and for heterogeneity across countries. Using per capita real GDP as a controlled variable, we found a unidirectional causality running from military spending to unemployment for Canada, Japan, and the US, one-way causality running from unemployment to military spending for France and Germany, and bidirectional causality for Italy and the UK. The empirical evidence does not seem to provide consistent results regarding the causal relationship between military spending and unemployment in G7 countries. 相似文献
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We consider an M/G/1 retrial queue with finite capacity of the retrial group. First, we obtain equations governing the dynamic of the waiting time. Then, we focus on the numerical inversion of the density function and the computation of moments. These results are used to approximate the waiting time of the M/G/1 queue with infinite retrial group for which direct analysis seems intractable. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
265.
This paper finds the optimal integrated production schedule and preventive maintenance plan for a single machine exposed under a cumulative damage process, and investigates how the optimal preventive maintenance plan interacts with the optimal production schedule. The goal is to minimize the total tardiness. The optimal policy possesses the following properties: Under arbitrary maintenance plan when jobs have common processing time, and different due dates, the optimal production schedule is to order the jobs by earliest due date first rule; and when jobs have common due date and different processing times, the optimal production schedule is shortest processing time first. The optimal maintenance plan is of control limit type under any arbitrary production schedule when machine is exposed under a cumulative damage failure process. Numerical studies on the optimal maintenance control limit of the maintenance plan indicate that as the number of jobs to be scheduled increases, the effect of jobs due dates on the optimal maintenance control limit diminishes. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007 相似文献
266.
为进一步明确和规范消防行政强制执行在执法过程中的适用,对消防行政强制执行制度的现状、存在问题进行分析,并提出了完善消防行政强制执行制度的设想。 相似文献
267.
军事仿真想定开发方法研究 总被引:2,自引:0,他引:2
军事仿真系统是一个十分复杂的系统,其仿真想定开发耗时耗力.目前主要靠人工为各个系统定制仿真想定,由于定制过程中参与人员众多,而且每个参与者都具有不同专业领域的知识背景,这样做给以后大系统仿真带来诸多不可移植问题.为解决军事仿真想定中资源、协作等问题,整个军事仿真想定开发的标准化至关重要.在详细考查了仿真想定相关概念基础上,提出了一种分层次合作开发军事作战仿真想定的方法,总结出了仿真想定开发标准流程,并介绍了一种基于可扩展标记语言XML的军事想定定义语言MSDL. 相似文献
268.
对战车火控双屏显示系统进行了功能仿真,构建了坦克车长、炮长、驾驶员的宽屏显示和窄屏显示的仿真模型,通过调整屏幕分辨率、视场角度等参数对该系统进行了仿真对比试验,并对该系统最佳参数设置进行了评估. 相似文献
269.
美军天基武器装备的发展及启示 总被引:1,自引:0,他引:1
近年来,出于对空间优势地位潜在威胁的考虑,美军正加速推进空间控制战略,大力发展天基武器装备.介绍了美军天基武器装备的作战使命和发展历程,阐述了美军天基武器装备的类型及进展情况,最后给出了美军发展天基武器装备的若干启示. 相似文献
270.
The existing product line design literature devotes little attention to the effect of demand uncertainty. Due to demand uncertainty, the supply‐demand mismatch is inevitable which leads to different degrees of lost sales depending on the configuration of product lines. In this article, we adopt a stylized two‐segment setup with uncertain market sizes and illustrate the interplay between two effects: risk pooling that mitigates the impact of demand uncertainty and market segmentation that facilitates consumer differentiation. Compared to downward substitution, inducing bidirectional substitution through product line decisions including quality levels and prices can yield greater risk pooling effects. However, we show that the additional benefit from the risk pooling effect cannot compensate for the reduced market segmentation effect. We demonstrate that the presence of demand uncertainty can reduce the benefit of market segmentation and therefore the length of product lines in terms of the difference between products. We also propose three heuristics that separate product line and production decisions; each of these heuristics corresponds to one particular form of demand substitution. Our numerical studies indicate that the best of the three heuristics yields performance that is close to optimality. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 143–157, 2015 相似文献