Reliability of a 2-Unit Standby Redundant System with Repair, Maintenance and Standby Failure

A repairable 2-unit warm-standby system with repair and preventive maintenance is discussed. Two models are presented. In each of the models the mean time to system failure and the steady state availability are calculated. Some numerical calculations illustrate the results.     

Reliability of a 2-Unit Standby Redundant System with Constrained Repair Time

This paper considers a 2-unit warm-standby redundant system with repair. The repair of a failed unit is constrained as follows: Associated with each failure of a unit is a random variable termed the Maximum-Repair-Time (MRT) of the failure. If the repair of a failed unit is not completed within the MRT, the unit is rejected for further use. Two types of failure stituations for the system are considered: 1) No allowed down time, and 2) Some allowed down time. Expressions for the Cdf of the Time to System Failure (TSF) and the mean TSF are derived by using Markov renewal processes.     

Time Dependent Solution of a Complex Standby Redundant System under Preemptive Repeat Repair Discipline

The system has two classes of components. Each component in one of the classes is essential to operation. Components in the other class are helpful but not essential. The Laplace transforms of various state probabilities have been obtained; a particular case has been derived.     

两部件可修复温储备系统维修策略的改进

考虑由两个可修复元件、一个可修复的转换开关、一位固定的维修人员组成的两部件可修复温储备系统,为了提升系统可靠度,在维修策略上作了改进,提出了一位是固定维修工,两个及以上元件失效时雇佣一位临时工的方法。并建立了策略改进后所相应的Markov过程,通过Laplace变换给出了系统可靠性指标的计算模型,由案例分析获得策略改进后的模型可使系统的可靠性和可用度等指标在原有的基础上得以提高的结果,从而得到该策略的改进是合理和必要的结论。     

Analysis of 7 Models for the 2-Dissimilar-Unit, Warm Standby, Redundant System

The paper is in 2 parts. In all models the failure rates are constant, but repair rates need not be constant. The method of supplementary variables is used for solving the models. Part I considers the effect of priorities on reliability and availability for 4 basic models; 1) priority in both repair and operation; 2) priority in repair; 3) priority in operation; 4) no priority. Models 1 and 2 treat 2 repair disciplines: a) preemptive-repeat, b) preemptive-resume. We obtain 1) Laplace transforms of availability and reliability and 2) explicit expressions for steady state availability and for mean time to system failure. The effect of priority assignment to maximize steady state availability is discussed. Part II considers the effect of having different repair rates, depending on whether the failure was from standby or from operation. We obtain 1) Laplace transforms of availability and reliability and 2) explicit expressions for mean time to system failure.     

A Two-Unit Cold Standby Repairable System with One Replaceable Repair Facility and Delay Repair: Some Reliability Problems

1 Model and Assumption In reliability analysis of repairable systems, it is usually assumed that the repair facility neither fails nor deteriorates as well as the repairman is instantaneously available. So that the repair is started immediately upon the failure of a unit provided that he is not busily repairing another unit. However, in actual practice, the repair facility in a repairable system is subject to failure and can be replaced (or can be repaired) after it fails, and certain delay ac…     

洁净手术室使用中应注意的几个问题

结合医院外科手术室工作实践中出现的问题，根据国家相关标准和规范的要求，提出解决问题的具体措施和建议。     

智能终端操作系统安全问题及解决方案

阐述了智能终端操作系统安全的现状,剖析现有操作系统存在的安全问题.分析了国内自主操作系统的研发现状,探讨了在国内自主TIOS的基础上进行全方位安全加固的解决方案,分别对内核、系统支撑库、GUI、应用框架层进行加固,介绍了九大基础安全应用规划.最后,提出了不同类型用户和不同安全等级操作系统的安全需求,为各类安全手机开发提供参考.     

Unreliability of a Standby System with Repair and Imperfect Switching

We evaluate and analyze a model of a 2-unit standby system with repair and imperfect switching. The model determines the cumulative probability that system failure occurs in a time interval 0 to T. In order to cope with arbitrary failure-time and repair-time distributions, a ``step by step' method is used which for practical purposes yields a sufficiently accurate result. The model results in explicit expressions which are very suitable for computer implementation. A simple illustrative example is given.     

Reliability Programs and the Problem of Attaining High Probabilities of Mission Success in Space Exploration

The major obstacles to attaining high probabilities of mission success in future space exploration are described to be as follows: dependence on large numbers of propulsive stages in a given vehicle development of relatively many more long-lived components and subsystems than has been possible to achieve to date heed to improve the development process so that a reletively much ower volume of ground and flight testing is needed than formerly to provide confidence in system reliability and fragmentation of responsibilities for flight tests and for technical direction of major programs. Moreover, it is suggested that several aspects of current approach to ``reliability' might be doing more harm than good, It is then argued that Broader and more uninhibited discussion of difficulties to attainment of high probabilities of mission success is much needed, as well as more widespread, systematic, and intense search for posible failure modes at the system, subsystem, component, and part levels; 3) general persuasion that when reduction in funds occur, that the must largely go into stretching out schedules and not into reducing the volume of ground and flight testing; integrity of communication throughout the mtitiplicity of participating elements and the conviction that, reliability engineering is an inseparable integral aspect of systems engineering.     

Initial Provisioning of a Standby System with Deteriorating and Repairable Spares

A technique is developed for finding the time dependent operating probabilities used by reliability systems designers for provisioning a system with N + k identical units, k of which are called spares and N called operating units, and s repair facilities. System failure occurs when less than N units are operational. Units fail with exponential interfailure times and are repaired with exponential service time. Idle spares fail due to deterioration at a rate possibly different from that of the operating units. Graphs are presented which show the minimum numbers of spares needed to achieve system reliabilities of 0.90 and 0.99 as a function of time. The technique is applicable for finding, numerically, the first passage time distribution for any system modeled by birth and death processes.     

智能后备电源供电系统的研究与设计

针对双AC/DC变换器的热备份和冷备份连接方式存在的可靠性较低等问题,提出了智能双AC/DC变换器供电系统的两种新设计方案——数字逻辑控制电路和微控制器控制系统,实现了冷备份电源的自动切换,增强了电源的可靠性,较好地解决了直流电源持续供电的问题,其中的微控制器控制系统设计方案已成功应用于实际的网络传输设备中。     

新建煤矿监测监控系统中值得注意的几个问题

论述了建设煤矿监测监控系统的意义，计算机控制系统的一般构成和分类，提出了在新建煤矿监测监控系统时应该注意的几个问题。     

TDMoIP关键问题的研究与系统实现

随着传统TDM信息流向高性能分组主干网迁移成为潮流，TDMoIP技术由于其优势所在，发展日新月异。针对国内研究尚处起步阶段的现状，对TDMoIP关键问题进行分析和研究，并提出新颖的解决方案。最后给出用于IP和以太网环境下的E14路TDMover IP转换器的设计方案，具有一定的实践指导意义。     

CATV网络设计与施工应重点把握的几个问题

针对CATV网络设计、施工中防雷击、抗风吹、易维护等问题，分析了在CATV网络中容易遭受雷击、风吹的关键部位和部件，并提出解决办法。     

数据中心供电系统规划设计中的若干问题

规划设计是机房基础设施建设中最重要的环节。各种规模的数据中心运行实践表明,科学的规划设计是数据中心各种预期功能能否实现的关键,数据中心运行后的绝大多数问题也都起源于规划设计。文中根据当前数据中心供电系统建设和运行的情况,提出并分析了供电系统在规划设计阶段普遍存在的1O个问题,内容的重点在于提出问题,仅供数据中心用户信息主管和设计院工程设计人员参考。     

短波差分跳频有关系统及技术问题分析

基于当前短波差分跳频研究的现状及其基本原理,较全面地讨论了短波差分跳频中有关系统及技术问题,分析了差分跳频的优势和不足及其与传统跳频的不同点,得出了一些有益的结论。     

一个微内核操作系统的设计与实现

设计并实现了一个运行在Bochs虚拟机上的微内核结构的操作系统,详细描述了系统中进程管理、进程间通讯、基本内存管理、磁盘服务器以及文件服务器的设计和实现。并将实现的系统应用于安全路由器的开发中。本系统的实现将有利于从微观上观察操作系统的行为特征,更好地学习、理解和实践微内核机制。同时,也为面向特定应用开发嵌入式操作系统提供了实践经验。     

VC5416的几点问题及其与FLASH的引导系统的设计

文中介绍了TMS320VC5416在实际应用中的几个值得注意的问题.同时也介绍了VC5416与存储器FLASH构成的DSP引导系统的具体连接方式与操作方法,通过例子详细地说明了如何通过DSP芯片将程序烧写入FLASH,使FLASH与DSP芯片构成独立系统的步骤和方法,具有较强的实用性.