肇庆CINRAD/SA天气雷达故障与维护经验浅谈

通过对肇庆CINRAD/SA雷达运行2年的故障情况进行统计分析,从硬件设备和软件设施两方面来分析肇庆天气雷达在运行中所呈现出来的故障,进而整理出解决故障的方法和手段。希望通过分析更好地掌握新一代天气雷达故障的一些典型特点,为更好地维护维修雷达提供借鉴。     

某航空交通管制雷达故障分析

基于多年来对民用航空管制雷达故障所做的统计,搜集并整理了典型故障现象,根据该雷达的技术构成情况,结合具体工作环境因素对故障的影响,对雷达出现的故障进行了研究,分析了出现这些故障的原因。列举出几个分系统出现过的典型故障现象及其这些故障的排除方法,提出了一些提高该雷达可靠性的措施和改进性能的建议,这些措施在实际使用中取得了良好的效果。     

有效定位攻击源

在管理维护网络的过程中，总会不可避免地遇到上网频繁掉线、网络速度不快、数据传输丢包等现象。面对这些故障现象，怎样做到准确、有效地应对呢？其实，在很多时候，巧妙利用一些专业网络分析工具，经常可以化繁为简，从而能够有效定位网络攻击源。本文介绍的就是这样一则故障案例，希望大家能从中受到启发。     

配电线路故障排除及处理分析

随着我国社会经济的快速发展和进步，在人们的日常生活中，人们越来越多地使用到了电力能源。本文深入分析了近些年以来供电企业配电线路出现的一系列故障以及问题，并针对这些问题提出了一些改进和处理措施。     

数字电视前端信号异常故障排查方法

数字电视前端信号异常，是影响数字电视用户观看效果和质量的重要故障因素。引起数字电视前端信号异常故障的原因是多方面的。对此，主要从混合光纤同轴电缆（Hybrid Fiber Coax,HFC）光电混合网故障、同步数字体系（Synchronous Digital Hierarchy,SDH）主干光纤环网系统问题以及马赛克现象三个方面，具体分析引起这些故障的原因，特别对HFC光电混合网故障和马赛克现象问题的几个不同故障类型进行详细的阐释，并分析故障的排查方法。结合一个故障案例处理过程，介绍数字电视前端信号异常故障的排查流程和解决措施。最后，针对数字电视前端信号异常故障，从前端设备选择及安装等方面提出日常防护措施。     

一则营业账务数据库故障的分析

在承建某省的集中计费、营业账务系统的项目时,曾遇到过一些 ORACLE数据库的异常现象,由于这些故障现象非常特别,解决的步骤与方法也与以前不同,故特将故障现象及解决步骤整理如下.     

网络不稳定常见故障现象及解决

在网络维护的过程中,经常会遇到一些网络不稳定的故障。而这些网络不稳定的故障现象常使我们无从下手,甚至发生误判而影响整个网络的运行。笔者把所遇到过的几种故障现象及解决办法奉献出来,希望能给大家带来帮助。     

运行变压器故障分析及其处理方法

详细地介绍了运行中变压器各种故障的现象,表征,及相应的判断方法和处理措施。     

可靠性增长试验的体会

介绍了如何开展电子产品的可靠性增长试验 ,并就一些常见的故障现象、故障原因提出了相应的纠正措施。     

摄录像设备维修点滴

我台自一九八五年开始自办节目以来,先后购进了不少各种型号的摄录设备,十几年来,这些摄录设备在使用过程中,故障现象五花八门。本人根据十几年不断探索和大量设备的维修,对于一些较常见及典型故障,总结出一些快速排除故障法,现摘取几例仅供参考,这些故障的处理,对于我们这些地方小台维修经费不足,零配件短缺,在工作中会起到良好的作用。故障现象:ＶＯ—９８５０录相机绞带。检查步骤:打开机器,观察磁带运行情况,发现磁带在运行过程中带盘突然停转,磁带无。故障处理:由于手头无现成马达替换,本人将台里报废的ＶＯ—５６３０机的惰轮马达拆下…     

Sybase数据库日志满导致停机的恢复

介绍了Sybase数据库在银行信贷登记咨询系统的应用，由于日志满导致数据库停机的故障现象，故障检查分析方法，恢复步骤，探讨了故障预防及其对策。     

Reliability Analysis of Mechanical Systems With Bounded and Bathtub Shaped Intensity Function

This paper presents a new stochastic point process able to analyse the failure pattern of complex mechanical systems experiencing both early failures and degradation phenomena, and operating so long that the intensity function approaches a finite asymptote as the system age grows. We illustrate the characteristics of the proposed model. Then we give the maximum likelihood estimators of the model parameters, and some quantities of interest such as the s-expected number of early failures, the time of minimum intensity, and the minimum intensity value. Inference on the number of failures that will occur in future time intervals is also provided. We applied the proposed model to real failure data from the powertrain system of two buses operating in urban routes in the city of Naples.     

Design of integrated BiCMOS operational amplifiers with low-probability EMI-induced-failures

Electromagnetic interference may cause failures in operational amplifiers. The probability of these failures can be reduced by properly designing the opamp, once the failure mechanism has been discovered. In this paper the design of some integrated BiCMOS operational amplifiers with a very low-probability of electromagnetic interference (EMI) induced failures is reported. In particular, it is shown that opamps exhibiting good general performances as well as low EMI-susceptibility can be obtained only if their response to a large square-wave input signal is symmetric and the influence of some parasitic capacitances in the input stage is compensated. Following these guide-lines, we found possible to design BiCMOS opamp structures exhibiting EMI susceptibility of only a few mV up to several hundred MHz when they are driven with an interfering input signal of some volts.     

The common thread for operational reliability and failure physics

Operational reliability and failure physics constitute the two extreme ends of the reliability engineering spectrum. One critical common thread that ties these two extremes together is stress. Studies that relate failures and failure mechanisms to operational reliability through this common thread have been near non-existent. This paper is an attempt to stimulate interest to fill the gap for electronic systems. Flaws exist in a piece of electronic equipment at the time of manufacture, and stresses exacerbate these flaws to the point of equipment failure. There are no random failures. Every failure is relatable to certain stresses. Estimated flaw population distributions and stress versus time-to-failure characteristics show that electronic equipment failure rates should decrease with respect to time of stress application, such as operating time. Failure rate expressions have been developed for selected stresses (i.e., high temperature, thermal cycling, electrical stresses and vibration) and are discussed in detail in the text. Much more work is still required in equating the quantitative measures of stress to failure rates and operational reliability. This paper will help in paving the way towards that end.     

Real-time furnace modeling and diagnostics

Precise control of process temperature has become increasingly important in today's semiconductor industry. Multizone batch furnaces are used widely in current manufacturing lines, and high reliability of furnace systems is a crucial factor in achieving high product yield. However, uncertainty caused by sensor noise and failure may degrade reliability. In this work, the authors develop a methodology based on thermal modeling and sensor fusion techniques to detect temperature sensor failures, power supply failures, and system faults for the multizone furnace systems. The typical types of failures have been defined. The impact of single failures and different combinations of failures on the system behavior has been studied. The furnace system has been modeled based on both physical considerations and experimental data extraction. The fault detection methodology has been tested in simulations. Principal component analysis is utilized for choosing data types for different fault detection purposes. Sensor fusion is used to enhance reliability. Simulation results show that all different types of failures can be detected when data are rich enough. Experimental results show that all single failures and some of the failure combinations can be estimated when only steady-state and cooling-down data are utilized.     

Analyse des défaillances et suivi de la validation du logiciel d’un équipement de télécommunication*

This paper presents the results of the software reliability evaluation of a telecommunication equipment observed during its validation phase. Among the 2 146 collected failure reports, about 45% were discarded mainly because of the redundancy or the incompleteness of the information they contained. The statistical analysis of the selected failure reports allowed to study the classes of identified defects and their distribution among the software components and finally the failure modes. The evaluation of the software reliability measures was preceded by a trend analysis of the software reliability growth based on the Laplace test. Finally, the hyperexponential model was applied to follow up the evolution of the number of software failures during the validation phase and also to evaluate the software failure rate before the use of the system in operation with respect to the whole set of failures, and with respect to the most critical failures only.     

梳齿式MEMS加速度计在冲击下的失效分析

对Si基梳齿式MEMS加速度计在冲击下进行了失效分析,验证了其主要失效模式,分析了其失效机理。通过机械冲击实验并采用扫描电镜(SEM)、X射线透视系统、扫描声学显微镜(SAM)观察及电性能测试等分析技术,研究了梳齿式MEMS加速度计在冲击载荷下的结构与封装失效,运用材料力学理论加以分析论证,发现悬臂梁断裂是较为主要的失效模式,且此类器件的封装失效主要表现为气密性失效和装配工艺失效,为MEMS器件的可靠性设计提供了重要依据。     

Failure physics of integrated circuits — A review

This paper is a review of the most important results on failure physics of integrated circuits, as a synthesis of what has been recently encountered in the literature concerned with these problems.In the first part of the paper systematization of failure modes in integrated circuits is accomplished so that all failure modes are divided into four groups according to their origin: (i) failure modes associated with chip; (ii) failure modes resulting from leads and bonds; (iii) failure modes associated with encapsulation; and (iv) failure modes due to external effects and overstress. Also, some typical failure mode distributions of different types of integrated circuits are given and the effects of the changeover from LSI to VLSI on failure mode distributions are discussed.In the second part of the paper the most important tests for enhancing of the failure modes are enumerated and relationship between the failure modes and the tests for their detection is given. Also, the role of electrical testing by the curve tracer and the accompanying analytical techniques (scanning electron microscopy, transmission electron microscopy, electron beam microprobe, Auger electron spectroscopy and X-ray radiograph) are discussed. Finally, the diagnostic technique is described which, using simple electrical testing by the curve tracer and some tests for enhancing of the failure modes (high temperature bake and high temperature burn-in), enables simple detection of integrated circuit failure modes.In the third part of the paper a survey of test structures for failure analysis of integrated circuits is made. Test structures are divided into three groups according to the kind of the failure mode tested by them. First, the test structures for the analysis of the failures due to the process induced defects are described. Then, the test structures for the analysis of the failures due to traps at the interface silicon-oxide and mobile alcali ions in oxide are discussed. Finally, the test structures for the analysis of the metallization failures are considered.     

Catastrophic Failures in Power Systems: Causes, Analyses, and Countermeasures

Catastrophic failures of power systems are phenomena which occur with some regularity throughout the world. It is recognized that these cannot be prevented, although with the use of newer developments in power engineering, in communication systems, and in computer engineering it would be possible to reduce their frequency and their impact on society. Analyses of many blackouts point to some salient features which are common to most such events: power systems under stress because of high load levels or outages of important facilities, some initiating event-usually a fault, often followed by cascading effects due to unwanted operation of some protection systems. In particular, the role of hidden failures (HFs) in protection systems in propagating power system disturbances has become clearer with some of the recent research reported in the literature. This paper explores further the issue of HFs of protection systems and possible countermeasures. Regarding the countermeasures, adapting the protection systems so that they would change their operational logic from OR to a VOTING protocol has been discussed in the literature, and is well within the capability of present technology. Other hardware solutions, such as "Hidden Failure Monitoring and Protection Systems," have also been discussed in the literature. Most of these countermeasures will require intensive use of communication networks. Communication infrastructure will be utilized for real-time data transfer, as well as for slower speed data gathering tasks related to the condition of the power system. In this paper, we concentrate on the communication facilities and their applications for providing countermeasures against catastrophic failures of power systems.