Reliability and mean residual life functions of coherent systems in an active redundancy

In this article, the reliability and the mean residual life (MRL) functions of a system with active redundancies at the component and system levels are investigated. In active redundancy at the component level, the original and redundant components are working together and lifetime of the system is determined by the maximum of lifetime of the original components and their spares. In the active redundancy at the system level, the system has a spare, and the original and redundant systems work together. The lifetime of such a system is then the maximum of lifetimes of the system and its spare. The lifetimes of the original component and the spare are assumed to be dependent random variables. © 2017 Wiley Periodicals, Inc. Naval Research Logistics, 64: 19–28, 2017     

结合新装备开展教学研究

随着现代军事装备的发展,高新技术装备不断装备部队,作为军队工程技术院校,必须适应这种新形势。介绍和总结了指挥自动化教研室结合我院指挥自动化工程、通信专业的教学实际,以新装备为核心,开展教学和科研学术研究的经验。     

对高校行政管理改革的思考

如何提高学校管理的组织协调性是当前高校行政管理存在的突出问题之一。本文认为应从和谐发展理念构建高校行政管理与学术管理的新模式,特别要发挥绩效管理在高校行政管理中的作用,以促进高效率行政管理队伍的建设。     

Consecutive k‐within‐m‐out‐of‐n:F system with exchangeable components

As a generalization of k‐out‐of‐n:F and consecutive k‐out‐of‐n:F systems, the consecutive k‐within‐m‐out‐of‐n:F system consists of n linearly ordered components such that the system fails iff there are m consecutive components which include among them at least k failed components. In this article, the reliability properties of consecutive k‐within‐m‐out‐of‐n:F systems with exchangeable components are studied. The bounds and approximations for the survival function are provided. A Monte Carlo estimator of system signature is obtained and used to approximate survival function. The results are illustrated and numerics are provided for an exchangeable multivariate Pareto distribution. © 2009 Wiley Periodicals, Inc. Naval Research Logistics 2009     

基于检测统计量的修正转换恒虚警检测算法

提出了一种新的恒虚警检测算法--修正的转换恒虚警检测算法(MS-CFAR).该算法考虑检测单元采样作为参考单元的选择依据,其使用了基于转换恒虚警(S-CFAR)和最大选择恒虚警(GO-CFAR)的复合算法.给出了该算法在均匀背景中的数学分析.结果表明,该检测器既具有均匀背景下和CA-CFAR相近的良好性能,在多目标环境中亦克服了GO-CFAR不能分辨主目标的弊端,具有较强的适应性.尤其在杂波边缘环境中,MS-CFAR表现出了远好于S-CFAR的控制虚警的能力.     

Dynamic signatures and their use in comparing the reliability of new and used systems

The signature of a system with independent and identically distributed (i.i.d.) component lifetimes is a vector whose ith element is the probability that the ith component failure is fatal to the system. System signatures have been found to be quite useful tools in the study and comparison of engineered systems. In this article, the theory of system signatures is extended to versions of signatures applicable in dynamic reliability settings. It is shown that, when a working used system is inspected at time t and it is noted that precisely k failures have occurred, the vector s [0,1]^n‐k whose jth element is the probability that the (k + j)th component failure is fatal to the system, for j = 1,2,2026;,n ‐ k, is a distribution‐free measure of the design of the residual system. Next, known representation and preservation theorems for system signatures are generalized to dynamic versions. Two additional applications of dynamic signatures are studied in detail. The well‐known “new better than used” (NBU) property of aging systems is extended to a uniform (UNBU) version, which compares systems when new and when used, conditional on the known number of failures. Sufficient conditions are given for a system to have the UNBU property. The application of dynamic signatures to the engineering practice of “burn‐in” is also treated. Specifically, we consider the comparison of new systems with working used systems burned‐in to a given ordered component failure time. In a reliability economics framework, we illustrate how one might compare a new system to one successfully burned‐in to the kth component failure, and we identify circumstances in which burn‐in is inferior (or is superior) to the fielding of a new system. © 2009 Wiley Periodicals, Inc. Naval Research Logistics, 2009     

石墨烯微片尺寸对石墨烯纸热导率的影响

石墨烯热导率远高于传统金属薄膜等导热材料,可用作热扩散材料。石墨烯纸由石墨烯微片组装而成,石墨烯微片尺寸大小对其组装方式微观结构以及宏观导热性能等具有重要影响。采用溶液过滤自组装方法制备了分散均匀的氧化石墨烯纸,然后在Ar/H2气氛下对氧化石墨烯纸进行热还原处理,得到了石墨烯纸。结果表明,大尺寸石墨烯微片组成的石墨烯纸结构更加致密、结晶度更高;0.5μm~3μm和50μm~100μm的氧化石墨烯所制备的石墨烯纸的热导率分别为632.8 W/m K和683.7 W/m K,大尺寸石墨烯微片组成的石墨烯纸热导率提高了8%。     

火灾统计分析初探

火灾统计分析是将火灾统计数据转变为有效信息的一个环节 ,是为决策提供优质服务的切入点 ,是关系到火灾统计工作能否真正发挥对消防管理工作的“指示仪”、“校正器”作用的关键。文章叙述了火灾统计分析的一些相关内容 ,并就改进火灾统计分析进行了探讨。     

火灾统计工作中存在的问题及其对策

本文结合重庆市火灾统计工作实际,简要剖析在火灾统计工作中普遍存在的问题,并提出解决问题的对策。     

海底小目标数据库功能和运用方法研究

利用海底小目标数据库中的数据信息辅助探猎雷作战,可以摆脱传统探猎雷作战行动中的盲目性,优化反水雷作战流程,有效提高反水雷作战效率。如何科学构建数据库功能,合理设计数据存储、查询和调用的方式方法,以充分发挥各类探测数据的潜在作用,对辅助反水雷战术指挥决策具有重要意义。本文根据海底小目标对探猎雷作战的影响,提出目标位置比对、声纳图像比对、探测态势比对和数据统计分析是海底小目标数据库所应具备的主要功能,结合探猎雷过程中的典型作战环节,阐述了各项功能的基本运用方法和实现手段,指出数据的“量”“质”以及采集规范和维护管理制度,均是数据库建设的重要前提,并对建设数据库所应具备的保障条件进行了 说明。