多状态不可修复如新的n-1/n(G)系统的可靠性分析

故障模式并非一种,并且部件也不可能修复如新,因此研究了多状态不可修复如新的n-1/n(G)系统的可靠性。在部件的寿命和维修时间均服从指数分布情况下,采用补充变量法以及广义马尔科夫过程理论,得到了多状态系统的瞬时可用度,可靠度等可靠性指标的Laplace变换表达式以及系统首次故障前的平均时间,并以3中取连续2好系统为例说明了已得结论的实用价值。     

几种典型系统可靠度区间上下确界的计算

对系统可靠性串联、并联和n中取k可靠度区间的最小上界（LUB）和最大上界（GLB）进行了分析，这里假设系统的寿命分布是负指数型，并就系统中不同部件数目下，针对各种情况进行了详细的研究。     

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。     

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...     

(n,F,k)系统可靠性

(n,F,k)系统由n个单元组成,当且仅当大于F个单元发生故障,或者k个或k个以上相邻单元发生故障,则系统失效本文提出了(n,F,k)系统可靠性的一般计算公式,并给出该系统可靠性的上下界。     

n中取k表决系统的可靠性评估

文章主要以2/3[G]系统为例对k/n[G]系统的可靠性进行评估,并同单系统进行比较,为选取k/n[G]作为系统模型提供依据。最后讨论了k/n[G]系统的表决器可靠性要求。     

可靠性设计、试验与设备

0101818基于结构模型的系统级测试性设计(DFT)技术研究[刊]/钱彦岭//测控技术.—2000,19(9).—12～14(E)0101819开关寿命连续型冷贮备可修系统的可靠性分析[刊]/吴清太//南京航空航天大学学报.—2000.32(5).—556～561(E)对由 n 个同型部件和一个修理设备组成的、开关寿命为连续随机变量的冷贮备可修系统.当部件的工作时间和维修时间以及转换开关的寿命和修理时间均服从指数分布。所有随机变量均相互独立、工作部件的寿命分布与其贮备过多长时间无关、故障部件和转换开关修复后的寿命分布与新部件、新开关的寿命相同的条件下作了研究,建立了该类系统的一般模型,当 n     

计算线形和环形连续k-out-of-n:F系统可靠性的新算法

本文从最小割出发,运用不交和和方法来研究线形和环形连续ｋ－ｏｕｔ－ｏｆ－ｎ：Ｆ系统,最后得到了系统的失效概率计算公式,该算法的复杂度是Ｏ（ｎｋ）。     

三模冗余演化自修复系统可靠性及状态规律分析

为研究三模冗余演化自修复系统可靠性及状态规律,首先给出了系统架构及其工作 流程,继而以马尔科夫(Markov)过程理论为基础对其进行了可靠性建模,最后基于此模型对 系统可靠 性及状态规律进行了仿真研究。结果表明：修复率与故障率比值是影响系统可靠性的 主要因素;系统运作区间以可用度与可靠度差值的极值分为两大部分,极值点前,系 统主要处于状态0、1,演化修复作用对系统可靠性贡献不大;极值点后,系统在状态1、2间 转换概率提高,演化修复作用成为提高系统可靠性主要因素。所得结论对特定环境中系统的 设计、应用、评估具有一定的理论指导意义。     

相关竞争失效场合雷达功率放大系统可靠性评估

针对相关竞争失效场合难以获取高可靠部件的性能分布信息,无法对系统可靠性进行准确估计的问题.提出了相关竞争失效场合下考虑认知不确定性的多态系统可靠性评估方法.该方法首先通过假定部件突发失效阈值为递减型随机过程来表征累积退化与突发失效的相关性,同时为降低对部件认知不确定性的影响,假定冲击引起的部件性能损伤分布参数和突发失效参数均为区间变量,建立基于区间变量的部件性能分布模型;而后对传统的通用生成函数方法进行改进,给出了区间通用生成函数的定义及其运算法则;最后对某型雷达功率放大系统的可靠性进行分析.该方法不仅克服了部件的失效模式复杂、状态信息少的不足,且方法简单、思路清晰,具有很强的通用性和工程应用价值.     

Stochastic ordering results for consecutive k-out-of-n:F systems

A linear (circular) consecutive k-out-of-n:F system is a system of n linearly (circularly) ordered components which fails if and only if at least k consecutive components fail. We use recursive relationships on the reliability of such systems with independent identically distributed components to show that for any fixed k, the lifetime of a (linear or circular) consecutive k-out-of-n:F system is stochastically decreasing in n. This result also holds for linear systems when the components are independent and not necessarily identically distributed, but not in general for circular systems.     

Reliability of 2-dimensional consecutive-k-out-of-n:F systems

The authors derive lower and upper reliability bounds for the two-dimensional consecutive k-out-of-n:F system (Salvia Lasher, 1990) with independent, but not necessarily identically distributed, components. A Weibull limit theory is proven for system time-to-failure for i.i.d. components     

顺序k/n(F)系统可靠性算法改进

在元件可靠性不相同的一般情况下,本文给出了线状/环状顺序k/n(F)系统可靠性的计算方法,算法完全排除了所有可能出现的相消项,使系统可靠性公式中项数降到最少,且具有极强的规律性,从而大大减少了计算复杂度。     

Bounds for reliability of consecutivek-within-m-out-of-n:F systems

Upper and lower bounds for the reliability of a (linear or circular) consecutive k-within-m-out-of-n:F system with unequal component-failure probabilities are provided. Numerical calculations indicate that, for systems with components of good enough reliability, these bounds quite adequately estimate system reliability. The estimate is easy to calculate, having computational complexity O(m²×n). For identically distributed components, a Weibull limit theorem for system time-to-failure is proved     

Reliability of consecutive-k-out-of-n:F systemswith nonidentical component reliabilities

A system with n components in sequence is a consecutive- k-out-of-n:F system if it fails whenever k consecutive components are failed. Under the supposition that component failures need not be independent and that component failure probabilities need not be equal, a topological formula is presented for the exact system reliability of linear and circular consecutive-k -out-of-n:F networks. The number of terms in the reliability formula is O(n⁴) in the linear case and O(n⁵) in the circular case     

Studies in Cascade Reliability?I

An n-Cascade system is defined as a special type of standby system with n components. A component fails if the stress on it is not less than its strength. When a component in cascade fails, the next in standby is activated and will take on the stress. However, the stress on this component will be a multiple k times the stress that acted on its predecessor. The system fails if due to an initial stress, each of the components in succession fails. The stress is random and the component strengths are independent and identically distributed variates, with specified probability functions; k is constant. Expressions for system reliability are obtained when the stress and strength distributions are exponential. Reliability values for a 2-cascade system with Gamma and Normal stress and strength distributions are computed, some of which are presented graphically.     

Reliability of a connected-(r1, s1)-or-(r2, s2)-or-..-or-(rk, sk)-out-of-(m,n): F lattice system

A (linear or circular) connected-(r₁, s₁)-or-(r₂, s₂)-or-^{. .}-or-(r_k, s_k)-out-of-(m, n): F lattice system is the (linear or circular) (m, n)-lattice system if the system fails whenever all components in a connected-(r₁, s₁)-submatrix or all components in a connected-(r₂, s₂)-submatrix or ^{. .} or all components in a connected-(r_k, s_k)-submatrix fail. This paper presents a recursive algorithm for the reliability of the (linear or circular) connected-(r₁, s₁)-or-(r₂, s₂)or-^{. .}-or-(r_k,s_k)-out- of-(m, n):F lattice system. The recursive algorithm requires time and time in the linear case and the circular case, respectively Furthermore, we can reduce the more computing time in the statistically independent and identically distributed case or considering some special systems. Especially, the closed formula is given for the reliability of the linear connected-(2, 1)-or-(1, 2)-out-of-(m, 2): F lattice system in the statistically independent and identically distributed case.     

A Heuristic Method for Determining Optimal Reliability Allocation

The paper presents a method for obtaining an optimal reliability allocation of an n-stage series system. In each stage, redundant comnponents can be added (in parallel, stand-by, or k-out-of-n:G, etc.), or a more reliable component can be used in order to improve the system reliability. The solution is obtained by repeatedly using a more reliable candidate at each stage that has the greatest value of a `weighted sensitivity function'. The balance between the objective unction and the constraints is controlled by a `balancing coefficient'. The overall computational procedure is given and an example is presented. The computations are given for a set of randomly generated test problems in which the optimal parallel redundancy under linear onstraints is determined. The proposed method is then compared with other methods.     

On Estimating Component Reliability for Systems with Random Redundancy Levels

Redundancy is a well understood and widely used design factor which can contribute appreciably to improve the reliability of a system. Reliability is improved, for example, when any fixed component is replaced by a parallel system of independent, identically distributed components. In this study, we discuss and treat problems in which the level of redundancy, K, is a random variable governed by a (known or unknown) discrete probability model. Given repeated observations on K and on the lifetime of a parallel system with K independent, identically distributed components, an estimator is derived for the reliability of the individual components. The consistency of the estimator is established, and its asymptotic distribution theory is discussed.     

An algorithm for computing the reliability of weighted-k-out-of-nsystems

This paper constructs a new k-out-of-n model, viz, a weighted-k-out-of-n system, which has n components, each with its own positive integer weight (total system weight=w), such that the system is good (failed) if the total weight of good (failed) components is at least k. The reliability of the weighted-k-out-of-n:G system is the complement of the unreliability of a weighted-(w-k+1)-out-of-n:F system. Without loss of generality, the authors discuss the weighted-k-out-of-n:G system only. The k-out-of-n:G system is a special case of the weighted-k-out-of-n:G system wherein the weight of each component is 1. An efficient algorithm is given to evaluate the reliability of the weighted-k-out-of-n:G system. The time complexity of this algorithm is O(n.k)