A Decomposition Method for Computing System Reliability by a Boolean Expression

A substitutionary decomposition method for computing the reliability of a redundant system S given by a Boolean expression is proposed, System S is decomposed into two subsystems S(x) and S(x?) according to up-and down-states of its keystone variable x. This is repeated until all terms become s-independent in each decomposed subsystem. A criterion for choosing the keystone variable and a property which saves computation time are obtained.     

A Decomposition Method for Computing System Reliability by a Matrix Expression

A decomposition method using a matrix representation for computing the reliability of a redundant system is proposed. The system is decomposed into two subsystems according to up- and down- states of a keystone element. This is repeated recursively until all subsystems have known reliability. The criterion for choosing the keystone element and an algorithm for decomposing a system are described.     

A Recursive Method Based on Case Analysis for Computing Network Terminal Reliability

In this paper a unified treatment is provided of the methods for computing terminal reliability based on recursive case analysis. The possible choices in case enumeration are discussed, and a rationale is given to support a particular policy. Simplification and decomposition techniques are also examined, and some experimental results are described, obtained with a computer program, which is a good compromise between efficiency and simplicity.     

A Simple Technique for Computing Network Reliability

A tree construction technique to compute a reliability expression of a network is derived. The technique is straight forward and good for both directed and undirected graphs. It gives mutually disjoint success branches. The reliability expression of each branch can be directly written by a set of rules. The reliability of the network can then be obtained by taking the direct sum of the reliabilities of the branches. It involves fewer multiplications than other known techniques. For a moderately complex network it is very easy to use this technique for evaluating reliability.     

Factoring Algorithms for Computing K-Terminal Network Reliability

Let GK denote a graph G whose edges can fail and with a set K ? V specified. Edge failures are independent and have known probabilities. The K-terminal reliability of GK, R(GK), is the probability that all vertices in K are connected by working edges. A factoring algorithm for computing network reliability recursively applies the formula R(GK) = piR(GK * ei) + qiR(GK - ei) where GK * ei is GK, with edge ei contracted, GK - ei is GK with ei deleted and pi ? 1 - qi is the reliability of edge ei. Various reliability-preserving reductions can be performed after each factoring operation in order to reduce computation. A unified framework is provided for complexity analysis and for determining optimal factoring strategies. Recent results are reviewed and extended within this framework.     

A Modified Technique for Computing Network Reliability

Ahmad (1982) has published a technique to compute the reliability of a network without resorting to paths or cutsets. However, the technique uses a random choice of next node connected to the previous node in the construction of a tree. This approach can lead to a large number of terms in the reliability expression. Our modified version of the Ahmad technique always produces a reliability expression with the same or fewer terms as the original technique.     

Reliability Evaluation by Network Decomposition

The method evaluates the reliability of large computer communication systems by systematic decomposition of the probabilistic graph of the system into two parts using an appropriate cutset. A technique is evolved for determining the conditional success events using both the node removal and connection multiplication methods for path enumeration. An example is solved to show the versatility of the method. The results of the example are verified by using an existing algorithm. The suggested method is general and computationally economical.     

A Method for Computing Complex System Reliability

The computation of reliability becomes quite tedious when one has to deal with a non series-parallel system. In this paper a proposed method is developed by taking the system as a probabilistic graph in which a component of the system is represented by a branch. The proposed method is composed of three phases: Phase 1 involves the reduction of all series, parallel, and series-parallel components to an irreducible non series-parallel system. In Phase 2 the algorithm enumerates all possible paths from the source to the sink of the graph. Phase 3 then computes the system reliability based on the path information obtained in Phase 2. An example of the use of the method to compute system reliability is given.     

以服务器为中心的面向服务网络计算架构的研究与实现

文章首先介绍了网络计算现状及本项目发起的原因,然后阐述了一套自主开发的以服务器为中心的面向服务网络计算平台SOINC(Service Oriented Infrastructure for Network Computing)系统的结构及其工作原理,并以软件仿真验证了该系统实现的可行性。     

On Reliability Evaluation by Network Decomposition

A simple algorithm for evaluating the symbolic terminal-pair reliability of a complex system is presented. The system graph is decomposed into two subgraphs through a minimal cut. The system success is expressed in terms of certain successes of these subgraphs, and then changed into an equivalent disjoint expression which is directly converted on a one-to-one basis into a reliability expression. It yields unusually simple reliability expressions. The algorithm can be computerized but has not been done. Three examples illustrate the algorithm and compare it with other algorithms.     

网络系统可靠度的BDD算法

文中研究3-状态设备网络系统2-终端可靠度的计算问题。BDD是布尔函数的图形表示形式。武小悦和沙基昌提出了一个采用BDD方法求2-状态网络系统的不交化最小路集,从而直接计算网络系统可靠度的算法。通过引入简化技术,结合归约公式和BDD技术,给出了一个计算3-状态设备网络2-终端可靠度的一个新算法;算法有效地消除了冗余项,并且产生的分枝树具有结点少,可有效得到可靠度符号表达式。     

A Method for Calculation of Network Reliability

The calculation of the probability that communication between two nodes in a given network is disrupted is difficult when the number of channels is large or when the network configuration is complex. This paper presents an efficient method, formalized as an algorithm, for calculating this probability using subnetworks that are smaller than the original one. This algorithm should prove useful in practice since it permits the possibility of choosing the subnetwork decomposition that one considers best suited for a specific problem.     

关于概率网络可靠性的一种评估方法

论文主要针对概率网络,提出了一种评估其可靠性的指标,给出了其数学解析式。在文章最后假定了概率网络的一个实例模型并且对其进行了可靠性分析。该指标考虑到了通信节点间数据交换的不对称性;网络拓扑结构和它的时变性;网络链路和节点的不可靠性以及网络的迂回路由问题,能够简单、直观地反应整个概率网的可靠性和抗毁性。     

基于路径函数和BDD的网络可靠度分析

现有的二终端网络可靠度评估方法,多数基于不交积和,由于没有充分利用普遍存在的同构子网特性,导致存在大量冗余计算,无法适用于大型网络．为此,本文提出了一种基于路径函数和BDD的网络可靠度分析方法,利用图Hash技术识别同构子网,从而简化路径函数的构建,再利用BDD高效地操纵路径函数计算网络可靠度．实验结果表明,该方法性能稳定且高效,适用于更大规模的网络可靠性分析．     

基于贝叶斯网络的导弹系统人因可靠性分析

分析了人在回路电视制导导弹系统研究飞行员可靠性的必要性。针对人的可靠性研究行为学策略,建立了飞行员可靠性评估的贝叶斯网络模型。论述了利用该模型进行评估的基本步骤,建立了其评价指标体系,并通过实例对飞行员人因可靠性进行了评估和研究。仿真结果证明了该模型的正确性和有效性,为飞行员发现自身不足提供了理论依据。     

一种计算Ad hoc网络K-终端可靠性的线性时间算法

研究计算Ad hoe网络K-终端可靠性的线性时间算法,可以快速计算Ad hoe网络K-终端可靠性。为了计算Ad hoe网络分级结构尽终端可靠性,可以采用无向概率图表示Ad hoe网络的分级结构。每个簇头由已知失效率的结点表示,并且当且仅当两个簇相邻时,两个结点间的互连由边表示。这个概率图的链路完全可靠,并且已知结点的失效率。此图的K-终端可靠性为给定K-结点集是互连的概率。文中提出了基于合适区间图计算尽终端可靠性的一种线性时间算法。本算法可用来计算Ad hoe网络的K-终端可靠性。其时间复杂度为O（｜V｜＋｜E｜）。     

计算无圈有向网络ST可靠性的一个新方法

本文考虑计算无圈有向网络的ＳＴ可靠性问题（至少存在一条从源点ｓ到汇点ｔ的正常运行道路的概率）。文章引进了深度优先搜索（Ｄｅｐｔｈ－ＦｉｒｓｔＳｅａｒｃｈ）有序根树的概念并提出一个新的计算无圈有向网络ＳＴ可靠性的拓扑公式。以该公式为基础,我们利用ＤＦＳ方法提出一个新的计算无圈有向网络ＳＴ可靠性算法,它能生成简洁的可靠性表达式,进而有效地计算无圈有向网络的ＳＴ可靠性。两个例子例证了我们的结论     

用贝叶斯统计推断进行系统可靠性分析的方法

贝叶斯分析是综合了人为主观判断和试验数据的一种推断方法,根据获得的累计失效时间数据,采用该方法对串联系统可靠性特征量进行了分析。     

Two Algorithms for Computing Reliability

This paper developes two algorithms for finding the time-dependent reliability of any active-redundant system in terms of component failure probabilities. These algorithms apply to non-loaded, continuously-operating systems in which drift-type failures are neglected. The first algorithm is used when each component can fail in only one mode. A procedure, based on the Quine-McCluskey technique from switching circuit theory, is stated in conjunction with this algorithm which permits rapid simplification of the reliability expression. Two failure modes are permitted in the second algorithm. The relation between the expressions resulting from the algorithms and lifetime random variables is given so that the algorithms do not depend on specific component failure distributions.