Reliability analysis of a Markovian deteriorating system

The reliability of a complex system passes through a gradual deterioration until at some critical level, the system fails completely. The study of such a system failure requires the application of Markov processes to obtain reliability measures such as mean time of system failure. The Laplace transform of reliability of the system starting from each operating state is employed for solving such a complex system of differential equations. A four-state deteriorating system is considered and various particular cases of the arbitrary repair times distribution are discussed.     

并行多控制器光盘阵列系统

介绍了一种新型的并行多控制器光盘阵列系统。在传统的光盘阵列系统中,往往采用单一控制器控制多驱动器阵列系统,但主机对于连接的驱动器数目有特定限制,对阵列整体性能也有所限制。该系统中采用并行多阵列控制器组成光盘阵列。试验证明,采用该方法设计的光盘阵列相对于传统的光盘阵列系统可以有效地降低系统的复杂程度,取得良好的控制效果。     

一种分层并行计算的软件化雷达系统

为解决软件化雷达系统实时处理大规模数据的问题,提出了一种分层级的分布式并行计算方法,并设计了一种低延时大规模数据处理能力的软件化雷达系统.该系统采用三层并行计算方法,利用ZeroMQ技术实现了任务级的分布式计算,多线程技术实现了线程级的多核并行计算,Arrayfire平台实现了数据级的图形处理单元(Graphic Pr...     

On a vacation queue with instantaneous customer loss

The paper studies an M/M/1 queueing system with variable batch-size arrivals and single exponential departures. The system is subject to time-homogeneous server vacations. In addition, a variable bulk customer loss of j units occurs with probability π_j (j = 0, 1, 2, 3,.. . M) where Σ π_j = 1 , at an instant when a vacation starts. The vacation times follow a general probability distribution. The probability generating functions of the number in the system have been determined and some particular cases of interest have been discussed. Finally some steady state results have been derived.     

On distribution of cycles in a Markovian queueing system

This paper studies the probability distribution of the number of cycles completed in a single-server queueing system with Poisson arrivals, exponential service times and having a limited capacity. The expressions for the number of cycles completed in the time interval (0, t] and the distribution of the number of busy periods completed in time interval (0, t] are obtained explicitly. These distributions are contemplated through the joint probability distribution of the number of customers in the system at time t and the number of times the system reaches its extreme state in the interval (0, t].     

新型排列组合高压缩多载波调制系统

提出一种基于高压缩多载波调制(HC-MCM,high compaction multi-carrier modulation)技术和排列组合正交频分复用(PC-OFDM,parallel combinatory OFDM)技术的新型调制系统,即排列组合高压缩多载波调制(PC/HC-MCM)系统。同PC-OFDM系统相比,PC/HC-MCM能够大幅度提高系统的带宽效率。同时给出了2种PC/HC-MCM系统的仿真性能。PC/HC-MCM系统稍加改造可以应用于不同的多载波系统。     

A two-unit parallel redundant system with bivariate exponential lifetimes

In this paper we discuss a two-unit parallel redundant system with a single repair facility in which the lifetimes of two units obey a bivariate exponential distribution and the repair time of the failed unit obeys an arbitrary distribution. Applying an extended Markov renewal process, we obtain the quantities of interest thoroughly in reliability theory.     

A complex two-unit parallel system

Reliability and availability functions are obtained for a complex two-unit parallel system by the use of regeneration point technique. The system consists of two dissimilar units. There is only one repair facility. The repair facility is not available for a random time immediately after each repair completion.     

On a series parallel system

Expressions for the Laplace transform of the availability of a complex system consisting of two subsystems is obtained by identifying suitable regeneration points.     

N-unit parallel redundant system with multiple correlated failures

This paper deals with mathematical models of an N-unit parallel redundant system with one repair facility and multiple correlated failures. These models are generalized on the basis of the results obtained previously and related to a system subject to a process of single failures and double and N-unit correlated failures. The method of the supplementary variable in two models differing by the repair policy is used. We obtain the following results: for both models the stationary availability, and for the second model the Laplace transform (L.T.) of the system reliability, L.T. of the pointwise a vailability, and the mean time to system failure (MTSF).     

并行多通道模式识别系统的研究

本文研究了在相干光和非相干光照明下,微透镜阵列的并行处理特性,并利用这种特性构造了并行多通道模式识别系统。     

Reliability analysis of a multicomponent system in a multistate Markovian environment

Consider a system which operates in a randomly changing environment. The changes of environmental levels are described by a Markov process with finite states. The system consists of several units and one repair facility, the repair time of a failed unit has an arbitrary distribution. We obtain the system reliability functions, availabilities and failure frequencies.     

一种基于集群的新型并行文件系统研究

首先阐述了基于集群的并行文件系统和并行I／O研究的必要性及其现状。然后提出了一种应用于集群中并行文件访问的新型并行文件系统CLUPFS，介绍了CLUPFS中的数据表示。包括文件分割模型、文件拆分后物理子文件与逻辑视图之间的转换，最后指出了CLUPFS并行文件系统进一步研究与实现的方向。     

Cost-benefit analysis of a multi-unit parallel trichotomous system with random shocks

This paper deals with the analysis of profit function of an n-unit parallel trichotomous system subject to random shocks. Failure times are assumed to follow negative exponential distributions with different parameters whereas the repair time distributions are taken to be general. Several reliability characteristics of interest to system engineers/designers as well as operation managers have been evaluated using the supplimentary variable technique.     

并行调度两级轮询控制系统分析研究

为了保证系统公平性不受损害,文中提出中心站点采用门限服务,普通站点采用并行调度完全服务的两级优先级轮询控制系统模型。通过马尔科夫链与概率母函数相结合的方法对模型的平均排队队长、平均等待时间等重要参数进行解析。经仿真得出,模拟仿真值与理论值误差较小,近似相等,表明模型理论分析合理正确。数值结果对比表明,模型区分网络业务高低优先级的性能优良,且普通站点工作效率得以提高,从而保证了系统公平性。     

连接计算机并口的数据采集系统

针对目前大多数导弹测试数据都从测试计算机并口输出,设计了基于单片机对测试数据进行并口采集的系统,通过介绍打印机的工作模式和工作时序,给出了并口数据采集的原理、系统的接口电路和软件编程的流程图,且给出了中断程序的代码,最后通过用样本数据调试系统,证实该系统数据接收效果令人满意、实时性好。     

On the increase of system reliability by parallel redundancy

Adding parallel redundancy to different components generally yields different system reliability improvements. The effect of such parallel redundancy upon system reliability when applied at various places and in various systems is investigated. The problem of how to choose components for parallel redundancy is studied, and some results are given. Some examples are presented to illustrate the approach     

Bayesian shrinkage estimation of reliability in parallel system with exponential failure of the components

The paper presents a Bayesian shrinkage method of estimating the reliability of a parallel system with identical exponential distribution of failure times. Data is available from type II censored samples. Thompson (J. Am. Statist. Ass.63, 113–123, 1968) proposed the ordinary shrunken estimator ?θ + (1-?)θ₀, with ? a constant (0 ? ? ? 1) and θ₀ the prior or guess value of θ, which is more efficient than the unbiased estimator θ if θ is close to θ₀ and is less efficient otherwise. Here we postulate a prior distribution of θ around θ₀ and use an ordinary Bayes estimator of θ instead of θ₀ in the ordinary shrunken estimator. The Bayesian shrinkage estimator of parallel system reliability has thus been obtained and Monte Carlo study of its efficiency with respect to unbiased and maximum likelihood estimators (mles) was conducted. It was found that the proposed estimator is better.     

An approximation analysis for the availability of a parallel redundant system with general distributions

This paper presents an approximation method for deriving the availability of a parallel redundant system with general distributions. The system discussed is composed of two identical units. A single service facility is available for the performance of preventive maintenance(PM) and repair. The failure times, repair times and PM times are assumed to be arbitrarily distributed. The presented method formulates the problem of the availability analysis of a parallel redundant system as a semi-Markov process which represents the state transitions of one specified unit in the system. This method derives the availability easily and accurately. Further, when all the distributions are exponential, the availability obtained by this method is exact.     

Markovian source separation

A maximum likelihood (ML) approach is used to separate the instantaneous mixtures of temporally correlated, independent sources with neither preliminary transformation nor a priori assumption about the probability distribution of the sources. A Markov model is used to represent the joint probability density of successive samples of each source. The joint probability density functions are estimated from the observations using a kernel method. For the special case of autoregressive models, the theoretical performance of the algorithm is computed and compared with the performance of second-order algorithms and i.i.d.-based separation algorithms.