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821.
Accelerated life testing (ALT) is commonly used to obtain reliability information about a product in a timely manner. Several stress loading designs have been proposed and recent research interests have emerged concerning the development of equivalent ALT plans. Step‐stress ALT (SSALT) is one of the most commonly used stress loadings because it usually shortens the test duration and reduces the number of required test units. This article considers two fundamental questions when designing a SSALT and provides formal proofs in answer to each. Namely: (1) can a simple SSALT be designed so that it is equivalent to other stress loading designs? (2) when optimizing a multilevel SSALT, does it degenerate to a simple SSALT plan? The answers to both queries, under certain reasonable model assumptions, are shown to be a qualified YES. In addition, we provide an argument to support the rationale of a common practice in designing a SSALT, that is, setting the higher stress level as high as possible in a SSALT plan. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2013  相似文献   
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824.
Consider a manufacturer serving a set of retail stores each of which faces deterministic demands in a finite planning horizon. At the beginning of the planning horizon, the production capacity of the manufacturer is built, followed by production, outsourcing to third party manufacturers if necessary and distribution to the retail stores. Because the retail stores are usually managed by different managers who act as independent profit centers, it is desirable that the total cost is divided among the retail stores so that their incentives can be appropriately captured and thus efficient operations can be achieved. Under various conditions, we prove that there is a fair allocation of costs among the retail stores in the sense that no subset of retail stores subsidizes others, or equivalently, the resulting capacity investment game has a nonempty core, that is, the capacity investment game is a balanced game. In addition, our proof provides a mechanism to compute a fair cost allocation. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 512–523, 2013  相似文献   
825.
We introduce an optimal stopping problem for selling an asset when the fixed but unknown distribution of successive offers is from one of n possible distributions. The initial probabilities as to which is the true distribution are given and updated in a Bayesian manner as the successive offers are observed. After receiving an offer, the seller has to decide whether to accept the offer or continue to observe the next offer. Each time an offer is observed a fixed cost is incurred. We consider both the cases where recalling a past offer is allowed and where it is not allowed. For each case, a dynamic programming model and some heuristic policies are presented. Using simulation, the performances of the heuristic methods are evaluated and upper bounds on the optimal expected return are obtained. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013  相似文献   
826.
Book reviews     
Norman Cigar, Genocide in Bosnia: The Policy of “Ethnic Cleansing”. College Station, Texas: Texas A&M University Press, 1995. Pp.xiv + 247; app., map, notes, cartoon.

Maria Jose Moyano, Argentina's Lost Patrol: Armed Struggle, 1969–1979. New Haven: Connecticut Yale University Press, 1995. Pp.xiii + 226, biblio., abbreviations, 10 figures, 1 map, tables, index; $25/£16.95. ISBN 0–300–01622–6.

Donald E. Schulz and Deborah Sundloff Schulz, The United States, Honduras, and the Crisis in Central America, Westview Thematic Studies in Latin America, Boulder, Co: Westview, 1994. Pp.368, map, figure, select biblio., abbreviations, index. $52.50/£37.50; (cloth) $17.95/£11.95 (paper). ISBN 0–8133–1324–4 and 1323–6.

Joseph H. Alexander and Merrill L. Bartlett, Sea Soldiers in the Cold War: Amphibious Warfare 1945–1991. Annapolis, Maryland: Naval Institute Press, 1995. Pp.iii + 178, 1 map, 29 illus, biblio, index. $32.95. ISBN

Gary P. Cox, The Halt in the Mud: French Strategic Planning from Waterloo to Sedan. Westview Press, 1994. Pp.258, maps, notes, biblio, index. £33.50. ISBN 0–133–1536–0.  相似文献   
827.
本文研究了节点负载处理能力异质条件下的无标度网络交通动力学过程,提出了一种基于节点资源利用率的全局动态路由策略。该策略利用网络中节点资源利用率构建了一种全局代价函数,选择使该代价函数最小的路径来传输负载。实验结果表明该路由策略在略微增加平均路径长度的情况下成倍地提高了网络负载传输能力,与有效路由策略的比较进一步验证了该策略的有效性。  相似文献   
828.
舰船辐射噪声在低频段具有稳定的线谱成分,其特征信息丰富,利用该线谱成分可以实现对水下目标的检测.被动合成孔径(Passive Synthetic Aperture Sonar,PSAS)算法对小孔径基阵沿直线运动接收到的信号进行合成处理,从而达到虚拟大孔径基阵的方位分辨力效果,进而提高对弱目标信号的检测能力.理论分析结合仿真不同因素对被动合成孔径算法影响,验证了算法的有效性和可行性.  相似文献   
829.
Y-切石英晶体的各向异性物理特性,使它在正碰撞或平面冲击波作用条件下能产生压剪波的传播,为实现对材料的压剪加载实验研究提供了条件。由于石英晶体的压电效应,国外采用了VISAR技术进行测试。在我们的工作中,首次尝试用锰铜压阻法和电磁质速测量法进行测试。压电效应造成了明显的干扰,妨碍信号的获取。实验中用磁控溅射方法将石英晶体表面镀银层约1μm,达到了中和极化电荷、屏蔽极化电场的目的,比较成功地消除了压电干扰,获得了有效的测试信号。  相似文献   
830.
本文根据动员需求与一般企业需求的特点,结合动员生产需求及信息化建设的实际情况,提出了一种基于动员快速响应的信息化动员生产指挥系统,并介绍了布署和建设实施方案,提出了国防工业企业信息化工作建议。  相似文献   
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