基于Copula的部件相依并联系统模糊可靠性分析

模糊可靠度是指产品在规定的使用条件下,在预期的使用时闻左右,在某种程度上保持其规定功能的概率。论文在考虑并联系统模糊可靠性元部件之间相依关系的问题上,从连接涵数copula出发,通过观测并联系统元部件的相关系数,解决并联系统的模糊可靠度及其平均寿命。并以Copula中Farlie-Gumbel-Morgenstern族寿命分布服从指数分布的情况下,解决此两类模糊可靠性指标。     

适用于高密度封装的失效分析技术及其应用

高密度封装技术在近些年迅猛发展,同时也给失效分析过程带来新的挑战.常规的失效分析手段难以满足结构复杂、线宽微小的高密度封装分析需求,需要针对具体分析对象对分析手法进行调整和改进.介绍了X射线、计算机辅助层析成像(CT)技术、微探针和多方法联用等失效分析技术,分析了其原理和适用于高密度封装的优势.并结合两个高密度封装失效分析案例,具体介绍了其在案例中的使用阶段和应用方法,成功找到失效原因.最后总结了各方法在高密度封装失效分析中应用的优势、不足和适用范围.     

基于Copula函数相依串联系统的可靠性分析

论文将Copula函数引人元件相依系统可靠性的研究中,利用Copula函数韵特性将两元件系统拟合为单部件系统,并求出拟合后系统的寿命分布函数;然后分别讨论了拟合后系统作为马尔科夫型与非马尔科夫型两种情况时的可靠性指标;最屠给出一个实例,并比较了系统相依葑独立时可靠性指标的差异。论文去除了传统研究中部件独立的假设,说明部...     

两个不独立共载并联系统模型的可靠性分析

为了提高系统可靠性，可以把多个相同的部件并联起来共同降额使用，构成共载并联系统，这种办法极为有效而又简单易行。在对这种系统进行可靠性分析时，通常假设各个部件之间是独立的，但实际上，各个部件之间并不是独立的。根据这种情况建立了两个高可靠性不独立共载并联系统的模型，进行了可靠性分析，并在失效时间服从指数分布的假设下计算出了系统的可靠度。     

An Assessment of Testing-Effort Dependent Software Reliability Growth Models

Over the last several decades, many Software Reliability Growth Models (SRGM) have been developed to greatly facilitate engineers and managers in tracking and measuring the growth of reliability as software is being improved. However, some research work indicates that the delayed S-shaped model may not fit the software failure data well when the testing-effort spent on fault detection is not a constant. Thus, in this paper, we first review the logistic testing-effort function that can be used to describe the amount of testing-effort spent on software testing. We describe how to incorporate the logistic testing-effort function into both exponential-type, and S-shaped software reliability models. The proposed models are also discussed under both ideal, and imperfect debugging conditions. Results from applying the proposed models to two real data sets are discussed, and compared with other traditional SRGM to show that the proposed models can give better predictions, and that the logistic testing-effort function is suitable for incorporating directly into both exponential-type, and S-shaped software reliability models     

The Failure Frequency of Systems with Dependent Components

The conventional approach to determining system failure frequency does not allow for dependent components. A novel approach presented here shows very clearly which information is needed to treat the case of dependence. The information is more complicated than that needed for system availability determination, yet it is of the same type, viz, joint probabilities or higher moments of joint binary processes. The main result is: System failure frequency can be found as the limiting value (for ?t ? 0) of the expectation of the product of the negated fault tree output at t and the usual output at t + ?t, all divided by ?t.     

Reliability and MTTF evaluation of a repairable complex system under waiting

This paper deals with the reliability and mean time to failure (MTTF) evaluation of a complex system under waiting incorporating the concept of hardware failure and human error. Failure rates of the complex system follow exponential time distributions, whereas repair follows a general repair time distribution. Laplace transforms of various state probabilities have been evaluated and then reliability is obtained by the inversion process. A formula for variance of time to failure has also been developed. A particular case is also given to highlight some important results. Moreover, various plots have been sketched at the end.     

Bounds on Reliability of a Coherent System with Positively Correlated Components

An upper bound on the reliability of a coherent system of positively correlated components is obtained via an improved Bonferroni inequality. An example is given. The bound is sharper if the joint survival probability is known for each pair of components.     

带等待时间约束并行机调度问题的Copula分布估计算法

本文针对一类带等待时间约束的不相关并行机调度问题,提出了一种基于Copula函数的分布估计算法.该算法以同类订单工件数与总工件数的比值为变量,对每台机器构造了一个Copula函数,进而建立了优势种群的概率模型.基于概率模型通过采样生成子代个体编码向量组,保留了父代种群的相对位置信息.从理论上分析了所提出算法的时间复杂度,其随工件个数的增加呈对数增长.通过基于实例的数值仿真以及与已有算法的比较验证了所提算法的有效性和鲁棒性.     

Sequential Testing of Components for System Reliability

It is often desirable to construct s-confidence limits for system reliability on the basis of data obtained from `pass-fail' tests on the components of the system. This paper presents a general method for sequentially testing the components that provides data from which these s-confidence limits can be easily derived. The method is applicable to any s-coherent system for which the reliability function is known. It is a generalization of a scheme given by Winterbottom and Verrall for systems composed of units arranged either in series or parallel.