复杂系统复合维修间隔期优化模型

采用组合策略对复杂系统辅以功能检测的定期更换维修工作进行综合优化.在分析复杂系统维修费用结构和组成的基础上,建立了其无限使用期条件下单位时间期望费用的数学模型,从而获得系统最佳的功能检测间隔期、定期更换周期内的检测次数和最优总费用.最后通过一个算例验证了该策略和模型的有效性.     

靶弹系统发展的某些新特点

靶弹系统建设对于防空兵器试验和部队作战训练具有重要的作用。介绍了靶弹的组成,美、俄等国靶弹系统研发现状以及主要型号靶弹的技术战术性能,详细分析了外军靶弹研发的特点和发展趋势,对我国防空兵器靶标体系建设有一定的参考借鉴作用。     

On optimal system designs in reliability‐economics frameworks

Reliability Economics is a field that can be defined as the collection of all problems in which there is tension between the performance of systems of interest and their cost. Given such a problem, the aim is to resolve the tension through an optimization process that identifies the system which maximizes some appropriate criterion function (e.g. expected lifetime per unit cost). In this paper, we focus on coherent systems of n independent and identically distributed (iid) components and mixtures thereof, and characterize both a system's performance and cost as functions of the system's signature vector (Samaniego, IEEE Trans Reliabil (1985) 69–72). For a given family of criterion functions, a variety of optimality results are obtained for systems of arbitrary order n. Approximations are developed and justified when the underlying component distribution is unknown. Assuming the availability of an auxiliary sample of N component failure times, the asymptotic theory of L‐estimators is adapted for the purpose of establishing the consistency and asymptotic normality of the proposed estimators of the expected ordered failure times of the n components of the systems under study. These results lead to the identification of ε‐optimal systems relative to the chosen criterion function. © 2007 Wiley Periodicals, Inc. Naval Research Logistics, 2007     

平稳小波的侧抑制网络边缘提取方法

侧抑制网络具有“突出边框,增强反差”的功能,但其增强反差的同时也增强了噪声,其抗噪性较差。正交小波阈值去噪法对图像噪声有一定抑制作用,然而对于图像中噪声幅度较大的情况下,正交小波变换会使图像边缘失真,甚至模糊。基于平稳小波变换的图像去噪法,可以有效降低噪声的同时较好地保持图像的质量,与基于正交小波变换的阈值降噪方法相比,有明显的优越性。因此利用新Bubb le函数将平稳小波和侧抑制网络结合起来,用平稳小波变换去除噪声、侧抑制网络突出边框,从而准确、有效地提取出图像的边缘。     

巡航导弹攻击路径组的优化与评估

为保证对敌方目标实施多次有效攻击,巡航导弹攻击路径选择的关键在于寻找一组优化路径而不是一条优化路径(如果存在),既满足性能指标要求,又满足作战应用要求.在作战区域内任意两个匹配区之间飞行航迹已知(专题讨论)的情况下,就巡航导弹攻击路径组的优化与评估问题进行了探讨,分析了导弹作战运用要求和性能指标要求,建立了攻击路径组的优化与评估模型,计算结果表明:所给出优化与评估模型是可行的,能够满足巡航导弹实际作战要求.     

从美国三大主力战斗机发展看战斗机的发展动向

以美国 2 1世纪列装的三大主力战斗机为背景 ,介绍了主力战斗机的研制情况 ,并对战斗机发展动向作了分析 ,指出以战斗机为主的飞机机群仍将是防空体系的主要威胁之一。     

群体决策与个人决策的选择

决策对于管理者来说至关重要,因为它关系到人们能否顺利实现目标.何时采用群体决策或个人决策,取决于三个方面的问题:群体决策和个人决策的效率,群体决策和个人决策的冒险倾向,以及小团体意识.     

机群超视距作战联合战术信息系统的效能分析

建立了机群联合战术信息系统在超视距作战中综合机群的传感器、导航和火力控制系统,组织对目标协同探测、辨识和火力控制的系统模型,以及它的效能评估模型.仿真计算表明此信息系统能有效增加机群超视距作战的效能,但噪声和欺骗干扰会显著地影响它的效率.     

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     

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