Evaluating cost and reliability integrated performance of stochastic logistics systems

The significance of integrating reliability into logistics performance has been established [The Logistics Performance Index and Its Indicators, World Bank International Trade and Transport Departments, (2010)]. Hence, as a response to the work by the World Bank, the present article aims to evaluate the performance index R_b,d of logistics systems as the probability that a specified demand d can be distributed successfully through multistate arc capacities from the source to the destination under the constraint that the total distribution cost should not exceed the cost limitation b. This article provides a pioneering approach for a straightforward computation of the performance index R_b,d. The proposed algorithm is a hybrid between the polynomial time capacity‐scaling algorithm, which was presented by Edmonds and Karp [JACM 19 (1972)], and the decomposition algorithm, which was presented by Jane and Laih [IEEE (2008)]. Currently, the proposed approach is the only algorithm that can directly compute R_b,d. An illustration of the proposed algorithm is presented. The results of the computational experiments indicate that the presented algorithm outperforms existing algorithms. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012     

逐步增加Ⅱ型截尾样本下k/N(G)系统可靠性指标的置信区间

在逐步增加Ⅰ型截尾样本下,研究k/N(G)系统可靠性指标的区间估计问题。假设部件寿命服从指数分布,利用极大似然法和Bayes方法,首先给出了部件失效率的Bayes近似置信区间,其次推导出了系统可靠度和平均寿命的Bayes近似置信区间的计算公式。最后给出随机模拟例子,并对置信区间的精度进行了讨论。     

水下传感器网络冗余设计

冗余设计可以有效地延长水下传感器网络寿命和提高网络可靠性,基于可靠性理论,考虑水下传感器网络环境及节点垂直移动等约束,在对冗余非共享方案研究的基础上,结合水下传感器网络特点,提出了适合于水下传感器网络特点的冗余共享设计方案,并给出了冗余共享方案的可靠性模型,通过数值计算,研究了网络可靠性变化曲线及冗余节点数与网络寿命的关系。经过MATLAB软件仿真,表明在同一网络寿命情况下,相对于冗余非共享方案,冗余共享方案所需冗余节点数更少,降低了网络部署成本,达到了冗余优化的目的。     

竞争失效产品恒应力加速寿命试验优化新方法

对加速寿命试验设计优化的相关知识进行研究分析,确定以竞争失效产品恒应力加速寿命试验为应用背景。在对加速寿命试验统计分析深入研究的基础上,通过分析方案要素、约束条件等建立优化目标函数,提出基于模拟退火算法的优化方法和具体实现思路。最后通过实例验证方法的可行性和实用性。     

高可靠性软件的极值统计分析

提出了极值统计分析的方法.对于失效数据极值分布函数的拟合检验,采用了相关系数法;对于母体分布的参数估计,则分别采用了最小二乘估计(LSE)和极大似然估计(MLE);最后通过一个实例说明了统计过程,并用模拟的方法证明了最小二乘估计较好.     

基于威布尔过程模型的坦克部署期可靠性研究

通过对某新研坦克部署期故障情况进行具体而全面的统计分析,并采用基于随机点过程的可修系统理论中的威布尔过程模型(AMSAA模型),得出该型坦克部署期的可靠性特点与规律,对于研究新装备可靠性规律和提高新装备的部署保障水平,具有重要的借鉴作用.     

Evaluating methods for the reliability of a large 2‐dimensional rectangular k‐within‐consecutive‐(r,s)‐out‐of‐(m,n):F system

A 2‐dimensional rectangular k‐within‐consecutive‐(r, s)‐out‐of‐(m, n):F system consists of m × n components, and fails if and only if k or more components fail in an r × s submatrix. This system can be treated as a reliability model for TFT liquid crystal displays, wireless communication networks, etc. Although an effective method has been developed for evaluating the exact system reliability of small or medium‐sized systems, that method needs extremely high computing time and memory capacity when applied to larger systems. Therefore, developing upper and lower bounds and accurate approximations for system reliability is useful for large systems. In this paper, first, we propose new upper and lower bounds for the reliability of a 2‐dimensional rectangular k‐within‐consecutive‐(r, s)‐out‐of‐(m, n):F system. Secondly, we propose two limit theorems for that system. With these theorems we can obtain accurate approximations for system reliabilities when the system is large and component reliabilities are close to one. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

Predictability of operational processes over finite horizon

Operational processes are usually studied in terms of stochastic processes. The main information measure used for predictability of stochastic processes is the entropy rate, which is asymptotic conditional entropy, thus not suitable for application over a finite horizon. We use the conditional entropy to study the predictability of stochastic processes over the finite horizon. It is well‐known that the conditional entropies of stationary processes decrease as the processes evolve, implying that, on average, their pasts become more informative about prediction of their future outcomes. Some important operational processes such as martingale, models for maintenance policies, nonhomogeneous Poisson, and mixed Poisson processes are nonstationary. We show that as a nonstationary process evolves, it may provide more information or less information about the future state of the system. We develop results for comparing the predictability of stochastic processes. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

基于作战效能的武器装备可靠性指标评估方法

装备可靠性的评估是装备管理使用中面临的重要课题.在总结前人的研究基础上,提出了一种基于武器装备作战效能的可靠性评估方法:建立非线性指标聚合的武器效能指标体系,通过主客观评分效果对底层指标进行打分,经过非线性指标聚合等手段获取装备效能的归一化评估指数,通过多次评估获取装备效能评估指数数据集,以此为基础对装备的可靠性进行评估.最后给出了评估仿真实例,实验结果表明所提方法的有效性、可行性.     

基于响应平面法的压力容器可靠性评定

针对压力容器制造、使用过程中各种参数的不确定性,提出了一种基于响应平面的随机分析方法.根据某压力容器的结构特点,确定性有限元分析采用了接触有限元,结合中心组合抽样设计构建了容器最大应力的响应平面,以此为基础对压力容器应力分布进行了随机分析.可靠性分析中引入应力—强度干涉模型,并分别对容器壁面和接管处进行了可靠性评定.实...