Bivariate mean residual life

An overview is presented of some theoretical results concerning the mean residual life function used in reliability theory. An extension of the concept to the bivariate case is introduced, and the relationship between the reliability and mean residual life function is derived. The properties of the function and conditions for asymptotic exponentiality of component life lengths are discussed     

Trend change in mean residual life

The authors consider a life distribution which shows a trend change in its mean residual life (MRL). The problem of testing such a trend change has been of great interest in reliability analysis. The authors propose a new procedure for testing the exponentiality against IDMRL or DMIRL, assuming that the proportion of the population, p, that dies at or before the change point of MRL is known. Their test provides a new competitor to the known test procedures, such as the Guess, Hollander, Proschan test and the Aly test. Based on the empirical powers of these tests against lognormal alternatives, their test outperforms the others for most sample sizes and most values of p and that all three tests achieve high power in detecting the trend change of MRL when p is very small and very large     

The class of better mean residual life at age t0

The conditional mean remaining life of an item of age t is called the mean residual life (MRL) at age t. In this paper we introduce a better mean residual life at t₀ (BMRL-t₀) class of life distributions, where the MRL decreases initially during [0, t₀] and then for t ≥ t₀ the MRL at time t is not greater than the MRL at t₀. It is shown that the BMRL-t₀ class contains the DMRL class, but it is a proper subclass of the NBUE class. The dual class of worse mean residual life at t₀(WMRL-t₀) is defined by reversing the direction of inequality. Some characteristics of these two classes are presented. We also develop the tests of exponentiality against the BMRL-t₀(WMRL-t₀) alternatives.     

Smooth nonparametric estimation of mean residual life

Smooth estimators of the Mean Residual Life function are constructed using complete and right censored data. Large sample properties of the proposed estimators are examined. Some numerical results are provided.     

Some results on discrete mean residual life

Mean residual life (MRL) is important in reliability studies; it provides the engineer with an idea of how long a device of any particular age can be expected to survive. Components and systems are frequently characterized as having increasing or decreasing MRL. Over the past 10-15 years, several authors have discussed MRL for components or systems whose lifetimes are measured in discrete units (number of trials until failure). This paper establishes some simple bounds for residual life when the device has a monotonic hazard rate sequence (either increasing or decreasing) and provides examples. MRL is obtained in closed form for a particular family of decreasing failure-rate models     

Bathtub failure rate and upside-down bathtub mean residual life

This paper shows that: (1) the mean residual life (MRL) of a component has an upside-down bathtub-shape if the component has a bathtub-shape failure-rate function, but the converse does not hold; and (2) there is an optimal burn-in policy to maximize the MRL when the underlying lifetime distribution has a bathtub-shape failure rate     

基于Bayes Monte Carlo方法的复杂系统平均剩余寿命评估方法

讨论了复杂系统平均剩余寿命评估的问题,首先基于先验信息和试验样本数据利用Bayes Monte Carlo方法给出了单个设备可靠性参数,然后结合系统的组成结构,求出系统可靠度函数,接着根据可靠度和平均剩余寿命之间的关系,建立复杂系统平均剩余寿命评估模型并给出具体的评估算法,最后,通过实例验证,表明本文的方法较为精确,能够满足工程的实际需求。     

Characterization of distributions by relationships between failurerate and mean residual life

The characterizations described use relations between the failure rate function and conditional expectation. The theorems proved here extend the results of some authors and can be used in the context of the renewal process. The utility of these results is demonstrated by using them to characterize some common distributions     

The Availability of a k-out-of-n:G Network

A method is described for calculating the analytic availability of a k-out-of-n:G network where the availability of each component may be different. An algorithm and a FORTRAN subroutine are provided to calculate this type of availability.     

一类多状态连续n中取k(G)系统的可靠性计算

为了计算多状态连续厅中取后（G）系统的可靠性,引入4个定理,将满足引理的多状态系统转换为二元状态系统。分别推导了多状态线形连续k／n（G）系统和环形连续k／n（G）系统的可靠性计算公式。证明了固定k值增加一个新部件,若部件可靠性独立同分布,线形和环形系统可靠性均增加;若部件可靠性独立但不同分布,环形系统存在一个极值,新增加部件可靠性大于这个极值时得到的新系统可靠性增加,反之系统可靠性下降。     

Reliability evaluation of k-out-of-n redundant system with partially energized stand-by units

A new probabilistic model representing an “n” units non-repairable system with “k” units operating and (n − k) units kept in stand-by mode (as partially energized) is represented in this paper. Human error, common cause and switching system failure are also considered in this modelling. The mathematical expression for state probabilities, reliability, mean time to failure and variance of time to failure is formulated. Numerical results are also presented to demonstrate the effect on unreliability and mean time to failure due to variation of redundancy in stand-by mode.     

本地网传输资源管理系统功能体系结构简介

全面介绍了江西电信本地网传输资源管理系统的功能和体系结构,并举例说明了网络管理流程。     

Mean residual life of lifetime distributions

This paper characterizes the general behaviors of the MRL (mean residual lives) for both continuous and discrete lifetime distributions, with respect to their failure rates. For the continuous lifetime distribution with failure rates with only one or two change-points, the characteristic of the MRL depends only on its mean and failure rate at time zero. For failure rates with “roller coaster” behavior, the subsequent behavior of the MRL depends on its MRL and failure-rates at the change points. Using the characterization, their behaviors for the: Weibull; lognormal; Birnbaum-Saunders; inverse Gaussian; and bathtub failure rate distributions are tabulated in terms of their shape parameters. For discrete lifetime distributions, for upside-down bathtub failure rate with only one change point, the characteristic of the MRL depends only on its mean and the probability mass function at time zero     

Reliability analysis of a k-out-of-n:G vehicle fleet

This paper presents a reliability analysis of a k-out-of-n:G on-surface vehicle fleet. The transit system is in a failed state when (n − k + 1) vehicles failed. Laplace transforms of state probabilities and reliability of the transit system are derived. The transit system steady-state probabilities and availability formulas are also developed.     

控制功能在NGN QoS架构中的实现

下一代网络必然是以基于IP的分组交换为核心的网络,为IP网络提供严格的Qos保证是NGN的必然要求,而引入控制机制、加强控制功能是实现IPQoS的关键所在。在给出NGN的QoS需求和QoS参考模型的基础上,对网络的QoS控制方式以及具有研究前景的几种QoS控制模型的思路、优缺点及可行性进行了分析。     

Nonlinear EMI simulation of an AM detector at the system level

A nonlinear detector simulation technique that can be used together with the discrete technique for a rapid radio receiver electromagnetic compatibility and electromagnetic interference (EMC/EMI) simulation up to the baseband signal processing path at the system level is proposed. The technique presented allows one to simulate an amplitude modulation (AM) detector in the large signal mode as well as in the small signal mode by taking into account the nonlinearity of the detector transfer characteristic. The technique was validated by making comparisons with measurements and PSPICE simulation data     

Characterization of bivariate mean residual-life function

This paper gives a counter example to invalidate a claim of Nair and Nair (1989) regarding a characterization of bivariate mean residual-life function (BMRLF). The authors characterize BMRLF of an absolutely continuous life-time distribution and, based on the form of the BMRLF, introduce probability models for bivariate life-time data     

省级无线电管理信息系统安全性初探

近年来．无线电管理机构大力推进信息化建设，使得各业务系统更加合理，整合度不断提高。然而，信息系统在提高行政办公效率和各项专业技术工作效率的同时，面临的安全威胁日益严重。因此，无线电管理信息系统安全性也被提升到前所未有的高度。近期，安徽省无线电管理信息系统进行了升级．并进入试运行阶段，本文结合该系统进行了信息系统安全性探讨。[编者按]     

Reliability Analysis of the k-out-of-n:F System

A class of repairable systems known as k-out-of-n:F systems, 1 ? k ? n, consists of n units in parallel redundancy which are serviced by a single repairman; system failure occurs when k units are simultaneously inoperable for the first time. In this paper, assuming constant failure rates and general repair distributions, reliability characteristics of the k-out-of-n:F system are treated using two different methods. In Part I, a conditional transform approach is applied to the 2-out-of-n:F system. Transforms of distributions are obtained for T (the time to system failure), the time spent on repairs during (0, T) and the free time of the repairman during (0, T). In Part II, the supplementary variable technique is used to investigate time to failure characteristics of the k-out-of-n:F system for k = 2 and k = 3. A model of an airport limousine service illustrates the use of the results.     

On the Evaluation of the Reliability of k-out-of-n Systems

The paper provides some correcting remarks on several methods to determine the k-out-of-n:G system reliability - a problem that has taken more than its share in the literature. A Jain-Gopal paper presents two algorithms JG-1 and JG-2 to evaluate the reliability of a k-out-of-n System. The comparison of the computational costs of JG-1 with those of JG-2 and with other existing algorithms, especially Barlow-Heidtmann, need to be restated.