Monitoring censored lifetime data with a weighted‐likelihood scheme

Lifetime experiments are common in many research areas and industrial applications. Recently, process monitoring for lifetime observations has received increasing attention. However, some existing methods are inadequate as neither their in control (IC) nor out of control (OC) performance is satisfactory. In addition, the challenges associated with designing robust and flexible control schemes have yet to be fully addressed. To overcome these limitations, this article utilizes a newly developed weighted likelihood ratio test, and proposes a novel monitoring strategy that automatically combines the likelihood of past samples with the exponential weighted sum average scheme. The proposed Censored Observation‐based Weighted‐Likelihood (COWL) control chart gives desirable IC and OC performances and is robust under various scenarios. In addition, a self‐starting control chart is introduced to cope with the problem of insufficient reference samples. Our simulation shows a stronger power in detecting changes in the censored lifetime data using our scheme than using other alternatives. A real industrial example based on the breaking strength of carbon fiber also demonstrates the effectiveness of the proposed method. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 631–646, 2017     

几个小样本检验统计量的研究

证明了n个相互独立的且服从(0,1)均匀分布的随机变量的乘积X服从定义的P(n)分布,并证明了Y=-lnX服从Gamma(n,1)分布。利用此结论提出了对非正态总体的小样本参数检验的理论和方法,讨论了指数分布、威布尔分布和艾分布的小样本检验问题。     

基于指标体系的火力分配模型研究

火力分配是现代作战中的关键问题,如何有效地进行火力分配对高效发挥火力、提高作战效能、争取作战的主动权具有重大意义。根据评价指标筛选原则,建立了一个反映目标价值的多层次评价指标体系,提出了火力分配的GEM-AHP计算模型。实例研究表明,该模型对多指标决策的火力分配问题具有很好的适用性。     

实时仿真系统体系结构设计的一般方法

针对目前文献中关于实时仿真系统的设计方案大多是围绕某个具体的任务而展开,缺乏一般性指导意义的问题,文中从实用的角度,提出了两种流行的实时仿真系统——集中式实时仿真系统和分布式实时仿真系统的总体方案,对方案的硬件结构、软件组成、优缺点、应用范围等进行了详细分析,这两种方案涵盖了目前常用的实时仿真系统的基本体系结构,对实时仿真系统设计人员具有实际参考价值。     

一种寿命分布类——剩余寿命按凸序递减类

在前人研究的寿命分布类的基础上 ,给出一种新的寿命分布类的定义 ,并研究了其有关的性质 (主要是封闭性质 )。     

kittel型反铁电相变的自由能

根据kittel型反铁电相变对称性的变化 ,选择轴矢量 R作为序参量是合适的。由Landau理论 ,相变温度附近的自由能F就可以写成 R幂级数展开的形式。令 F R=0 ,可得到关于序参量的方程 ,从而获得相变温度与自由能的关系     

装甲装备修理对象修理工作量的分布模型及应用

通过论述当今典型军队战时修理机构任务的划分,给出了装甲装备修理对象按照修理工作量和按照修理时间分布的2种模型,结合俄陆军各级修理机构修理时限的划分,计算得到了典型装甲装备的技术故障和战损产生的修理对象在各级修理机构的概率分布,为开展战损研究提供了一条新途径,对提高技术保障方案的准确性有积极作用。     

The value of losing control: Competition in markets for complements

When selling complementary products, manufacturers can often benefit from considering the resulting cross‐market interdependencies. Although using independent retailers makes it difficult to internalize these positive externalities, the ensuing double marginalization can mitigate within‐market competition. We use standard game theoretic analysis to determine optimal distribution channel strategies (through independent retailers or integrated) for competing manufacturers who participate in markets for complements. Our results suggest that a firm's optimal channel choice is highly dependent on its competitive positioning. A firm with a competitive advantage in terms of product characteristics (customer preferences) or production capabilities (cost) might benefit from selling through company‐controlled stores, allowing coordinated pricing across the two markets, whereas a less competitive firm might be better off using independent channel intermediaries to mitigate price competition. We consider two scenarios depending on whether the two firms make their distribution channel decisions sequentially or simultaneously. Although firms are unlikely to make such decisions at exactly the same instant, the simultaneous model also serves as a proxy for the scenario where firms decide sequentially, but where they cannot observe each other's strategic channel choices. For the sequential case, we find that the sequence of entry can have tremendous impact on the two firms'profits; whereas in some cases, the first mover can achieve substantially higher profits, we find that when the two markets are of sufficiently different size and only loosely related, a firm with a competitive advantage might be better off as a follower. Interestingly, our results suggest that, when the markets are of rather similar size, both firms are better off if they enter the industry sequentially. In those cases, the first entrant has incentive to reveal its planned channel strategies, and the follower has incentive to seek out and consider this information. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

中程空空导弹冲淡式干扰模型

中程空空导弹的末制导主动雷达一方面提高了中程空空导弹作战效能和载机的生成概率,另一方面也为对中程空空导弹实施冲淡式干扰提供了机会。基于冲淡式干扰的基本原理建立了中程空空导弹的冲淡式电子干扰模型,分析了各种不同攻防对策下的冲淡式干扰的效果及其变化趋势,在此基础上讨论了对抗双方在冲淡式电子对抗中的最优对策。     

多指标下的炮兵火力最优分配

为了提高炮兵火力打击效能,提出了小生境遗传算法与模糊多目标决策相结合的混合算法,建立了多指标下的炮兵火力分配模型,并阐述了混合算法设计,给出了应用举例,结果表明,与传统的单指标下的炮兵火力最优分配相比,该方法更符合战场实际情况。