与性能相关的容错计算系统可靠性指标

对于某些容错计算系统，由于成功与故障之间没有明确的界限，用传统的可靠性指标难以准确地评价其容错性能，为此一些学者提出了若干与性能相关的可靠性指标。本文将这些指标概括成三类（即基于瞬时性能的指标、基于累积收益的指标和率模可靠性指标）加以介绍，并简要介绍了它们的求解方法。     

Structural study of degraded ZnMgSSe blue light emitters

Using electroluminescence (EL) topography and transmission electron microscopy (TEM), we investigated the nonluminescent regions which form while current is being injected into ZnMgSSe/ZnSSe/ZnCdSe-based blue light emitters. Small dark spots were observed just after turn-on and spread out forming rough nonluminescent triangles in the <100> directions in the EL image of the active region. TEM studies showed that the small dark spots are pre-existing stacking faults originating at the substrate/epitaxial layer interface. The nonluminescent triangles were found to be a dense region of dislocation dipoles and dislocation loops. Each dipole was aligned along two <110> directions in the {111} planes. The Burgers vectors were of the type a/2<011> inclined at 45° to the (001) junction plane.     

用瞬态频率波动法诊断齿轮故障

利用瞬态频率波动法实现频率调制信号的解调，提取齿轮的局部裂纹信息，并通过黄河ＴＮ２５２型汽车变速器疲劳试验的信号分析来验证。     

全断面双护盾掘进机在引黄工程断层破碎带的卡机处理

万家寨引黄工程国际Ⅱ、Ⅲ标已查明的断层有34条，隐伏断层可能还有一些，除了利民堡区域性大断层（F32）外，较大的集中于7#洞北段59＋700—68＋820，主要有F65、F70、F90、F74。全断面双护盾掘进机适应于较复杂的地质条件，因此在通过断层破碎带时一般都较正常。但在通过引黄工程区域性大断层F65时，发生了卡机事故，处理用了3个月时间。该文对处理TBM卡机事故的施工进行了总结。     

浅议轨道交通直流牵引供电系统的构成及保护配置

介绍了城市轨道交通直流牵引供电系统的构成,详细叙述了直流牵引供电系统的主要电气设备及其连接方法,以及系统的运行方式.另外,还简单介绍了系统配置的直流保护以及保护原理和保护作用.     

Marmaray project: Tunnels and stations in BC contract

Istanbul is one of the most famous historical cities in the world. However, the project alignment selected as the best of a range of alignments cannot avoid passing beneath the historical and cultural heritages of Istanbul as well as under ancient and densely inhabited areas of the city. This paper will explain some of the challenges related to the bored tunnels.

Historical buildings are vulnerable. Yet many existing residential and office buildings are old and constructed on minimal foundations. As a consequence, it is vital that any drawdown of groundwater and any ground settlements have to be minimized.

In addition, the connection between the immersed and bored tunnels will be made directly and totally underground, without the usual intermediate shafts and beneath the deep waters of the Bosphorus Strait. This operation needs the utmost control of the tunnel excavation face to ensure its stability and to minimize water ingress. Based on such considerations, tunnel excavation by tunnel boring machine (TBM) using a slurry shield and having the ability to operate under high pore pressures was recommended as the method of excavation for the main running tunnels.

The paper will explain how the design team from Avrasyaconsult – the Employer’s Representative – arrived at the final minimum, specific and functional requirements of the bored tunneling works which are to be carried out using the ‘FIDIC EPC/Turnkey Project’ conditions.     

Developing real-time knowledge-based systems with PERFECT

PERFECT (Programming EnviRonment For Expert systems Constrained in reasoning Time) is aimed at providing the necessary engineering support in real-time knowledge-based system development. PERFECT bridges the gap between the traditional analysis and design methodologies, and the implementation tools for these systems. It does so by providing the means to construct a knowledge model and to choose a suitable inference strategy. Subsequently the properties of the knowledge model and inference strategy may be analysed. For instance, it may be checked whether the knowledge model contains sufficient knowledge to diagnose a fault in an industrial process. Moreover, it may be checked whether the inference engine is able to provide an answer to a certain problem in time. If not, the analyser of PERFECT proposes an alternative structure of the knowledge model. When the constructed knowledge model and the chosen inference strategy show the required time efficiency, the compiler of PERFECT may translate them to an actual real-time knowledge based system in COGSYS. In addition, guidelines are provided with respect to the design of the human-machine interface. The resulting system is an instrument—a source of information that can be used by the human operator during problem-solving, rather than a prosthesis—a device that solves the entire problem by itself and presents the outcome to the human operator.     

神经网络在电路诊断中的应用

目的：阐述了目前电路基于数据库技术和人工智能专家系统及神经网络原理的故障诊断系统。方法：将所记录的模糊症状输入到系统中，通过模糊运算后，运用神经网络学习算法来寻找故障类型。结果：介绍了人工神经网络技术在电路诊断中的应用，并给出系统故障诊断软件的设计，结论：所用专家系统和神经网络相结合的方法改进电子电路故障诊断是可行的。     

水电厂设备故障诊断系统实时数据库的一种简捷实现

实时数据库及时准确地从现场获取数据并有效地组织和管理，是水电厂 设备故障诊断系统进行故障诊断的首要条件。文中在分析了现有的实时数据库实现方法后， 用C++ Builder 5.0和SQL Server 7.0完成了实时数 据库实现的一种简洁方法，它不但能够满足工程需要，而且具有关系数据库所具有的一切强 大的数据库管理和维护功能，实现也很简单，极大地节省了实时数据库开发的人力和物力。 实验表明，该方法是可行的。