基于Petri网的地铁信号系统可靠性分析

地铁信号系统是地铁系统的中枢神经,同时也是提高地铁运营水平的重要保障。在分析信号系统功能及故障类型的基础上,划分了设备重要度水平。通过地铁信号系统Petri网5大对象子类框架的搭建,分析研究了信号系统重要设备发生故障的情况下,系统各子类的动态Petri网可靠性模型。     

基于弹性概念的城市轨道交通公交桥接问题研究

信号系统是肩负地铁行车安全和效率的安全苛求系统,为了应对信号系统故障难以避免的行车效率波动,提前制定地铁-公交联动应急预案是行之有效的手段之一。文章从轨道交通乘客体验出发,以轨道交通受扰后的恢复能力(即弹性)为优化目标,提出了一种综合考虑路面交通状况、地铁站点地理位置、地铁客流潮汐分布等因素的优化公交桥接应急预案生成方法。首先,在地铁站周边的地图数据的基础上叠加拥堵系数,建立道路拓扑网络模型;而后基于改进的k短路径法计算连接起点和终点地铁站点的最短路径,利用遗传算法优化相关站点所需公交数量,并将该方法应用于地铁5号线。仿真结果表明,通过在故障区域增加临时公交服务,对提升信号系统故障后的城市轨道交通系统弹性具有重要意义,且适当的公交桥接线路的调整更有助于系统弹性的提升。     

地铁故障即信号故障?冤枉!

<正>自百度、谷歌、360搜索等搜索引擎对以"地铁事故"为关键词的搜索结果进行盘点之后发现,在历年地铁事故引发原因的文章中出现最多的字眼即为"信号故障"。经媒体"曝光"过的"地铁信号系统故障"屡见报端,引来不少普通民众质疑,为何"信号故障"成为地铁"大患"并屡治屡犯?对于节奏不断加快的现代城市生活来说,轨道交通在公众的日常生活中占据着举足轻重的地位,因而只要地铁运营发生延误,大家可能就会产生"信号系统又发生故障了"的错觉。     

基于振动监测的地铁风机故障诊断研究

针对地铁机电设备检修管理特点,结合地铁风机故障诊断实际需求,以地铁射流风机振动信号为对象,通过振动监测和计算机技术,对风机的轴系故障、轴承故障、电机故障等信号数据特征进行采集,并实现时域特征、频域特征的提取与分析,进而找到能够区分地铁风机故障类型的信号特征,实现地铁机电设备的精准检修,为地铁设备的状态管理提供理论与应用依据。     

城市轨道交通信号控制下的列车失表处置对策

当轨道交通信号系统发生故障时极有可能导致列车失去联锁控制,将严重影响到运营的安全。列车失去在ATS信号界面上的显示,对于安全行车造成的隐患更大。对历年来上海轨道交通因信号故障导致的事故进行了分析,提出了信号故障情况下列车失表的应对措施。     

轨道交通

必维再获无锡地铁信号系统独立安全评估项目近日,必维国际检验集团获得为无锡地铁2号线信号系统提供独立安全评估项目。这是继宁波和武汉地铁项目后,必维在国内的又一个重要的地铁信号系统安全评估项目。据悉,无锡市轨道交通2号线正线全长26.301km,其中高架线6.734km,地下线19.567km。全线共设有车站22座,其中高架站4座,地下站18座,有道岔车站8座,无道岔车站14座。线路共穿越无锡市湖滨区、南长区、崇安区、     

浅析轨交ZC系统在故障情况下的应急处置

CBTC系统作为上海轨交10号线整套信号系统的一个核心组成部分,其系统的可靠性和安全性决定了实际运营的高效性。针对CBTC系统中ZC子系统的功能作了介绍,并对ZC系统故障处置进行了分析。结合ZC系统在目前10号线的运用,提出降低故障发生率的建议。     

地铁PCM系统2M口的自动切换

本文介绍了地铁１号线延伸线ＰＣＭ系统２Ｍｂｉｔ／ｓ自动切换系统。该系统将地铁各个重要专业的信息集中在某－２Ｍｂｉｔ／ｓ中传输在技术上对该２Ｍｂｉｔ／ｓ采用ＣＵＤＩＴＭＸ３０１＋１系统，从而保证重要传输通道在发生故障时瞬间不中断。     

上海地铁1号线南延伸直流保护系统改造分析

地铁直流牵引系统的安全可靠运行直接关系到地铁列车的安全、稳定运营,为此研究分析了上海地铁1号线南延伸段三个牵引变电所直流保护系统改造的目的及意义,重点描述了改造后新型设备的运行维护特点。     

访上海自仪泰雷兹交通自动化系统有限公司总工程师刘会明 城市轨道交通的“中国芯”

<正>3月17日上午,随着调度员的指令,上海地铁11号线迪士尼段正式动车并开始信号调试,短至90秒的发车间隔能力极大提高了运营效率,并方便运营方在未来实际运营中根据客流情况随时灵活调整运营间隔。据悉,迪士尼线信号系统建设方——上海自仪泰雷兹交通自动化系统有限公司(以下简称"上海自仪泰雷兹")在项目实施过程中,针对迪斯尼线的大客流、高密度特点,以客户需求为导向,对列车控制各子系统进行再开发,形成一     

Analysis of factors affecting the choice of route of pedestrians

Pedestrians as compared to vehicular traffic enjoy a high degree freedom of movement even in heavily congested areas. Consequently, there are more alternative links available to pedestrians between a given origin‐destination (O‐D) pair. This paper describes a study done by the University of Calgary to evaluate the factors affecting the choice of route on intra‐CBD trips or trips within the Central Business District (CBD).

An origin destination survey conducted in downtown Calgary, Alberta enabled the identification of the most significant factors influencing the choice. These factors were analyzed in relation to the physical characteristics of the location, personal characteristics of the trip maker and the type of the trip.

It appears that most people chose the shortest link and factors such as the level of congestion, safety or visual attractions were only secondary. This suggests that the length should be made a major consideration when planning and designing pedestrian links.     

实现多组态计量软件集中监控的可行性分析

天然气自动计量系统有多种组态软件,由于软件的不相通性,造成了计量系统数据采集的通用性差、数据传输与入库的时效性差、数据利用的可靠性低.结合各组态软件的实际情况,从设计上充分利用Oracle大数据处理能力以及Partition(分区表)的特性,实现历史数据的存储,应用WebService与COM+数据访问组件提供多层数据访问架构,采用OPC与DDE工业数据交换协议,实现了各站场计量数据的实时上传,为连续数据采集和实时监控提供了可能,节约了改造成本.     

注汽管道承压能力评估和实物试验验证

基于失效评估图技术对某注汽管道进行了承压能力评价,给出了管线在不同腐蚀壁厚情况下的极限承压能力和极限裂纹尺寸。并利用实物爆破试验验证了评价方法的安全性和有效性,通过对爆破断口进行宏观和微观分析,发现管段的开裂属于脆性开裂。     

Non-parametric analyses of efficiency of airports

This paper estimates the efficiencies and productivity changes of 12 international airports in the Asia-Pacific region based on data from 1998 to 2006. We apply stochastic frontier analysis (SFA) to compute efficiency estimates and use the Malmquist productivity index (MPI) to analyze productivity changes. We use the SFA model with a translog-type production function after testing the statistical hypotheses. According to the results of the SFA hypothesis tests, airports have experienced a technological regression; the deviations from the efficiency frontier are caused more by technical inefficiency than random noise. However, the inefficiency was found to decrease. The MPI reveals a declining trend resulting more from technological change than from efficiency change, with a decrease in inefficiency. Taken together, both the hypothesis tests and the MPI not only provide consistent conclusions, but also suggest that airports should concentrate on technological progress.     

波纹管应力分析研究进展

评述了波纹管应力理论研究方法的进展情况，围绕解析法、工程近似法和数值法，对波纹管理论研究中的一些主要成果作了较详细的回顾和总结，对各种研究方法作出了评价，展望了亟待解决的一些问题。     

输油管道中原油乳状液的流变性研究

原油乳状液的流变性是原油开采后在管道中输送的重要研究方面,为了更好地研究这一性质,采用电动搅拌机、偏光显微镜以及流变仪等仪器来测定不同含水率的原油乳状液在不同条件下的黏度,观测不同含水率的原油乳状液在偏光显微镜下的形态。并且分别对原油乳状液的黏度与含水率之间的关系以及与剪切速率之间的关系进行研究,初步确定了所测区块原油乳状液的转相点以及该区块原油乳状液的流变特性,为生产中的油气集输提供了理论依据。     

埋地管道防腐保温层失效评价

明确埋地管道防腐保温层的技术评价标准,对埋地钢质管道的安全运行,延长管道使用寿命具有重要意义。为了对埋地管道防腐保温层做出有效评价,从间接检测与开挖检测2个方面,结合现场检测数据,提出了基于防腐保温层的电流衰减率、绝缘电阻率、质量状况与厚度的分级评价标准及基于4种评价指标的综合评判方法。工程实践表明,该评价标准对防腐保温层是否存在失效能做出有效判断。     

城市轨道交通杂散电流监测系统概述

介绍了城市轨道交通工程中杂散电流不同的监测系统的构成,分析了集中式、分散式和智能型等监测系统的配置和功能,以及智能型实时在线监测系统的重要意义,为轨道交通工程杂散电流监测系统的选择与应用提供参考。     

Preliminary results of an analysis of areas of influence in Shanghai

The main deficiency of most current modeling approaches to transportation can be identified as neglect of the integration of existing geographical knowledge in regard to the ex ante transport/land use modeling approaches, with its focus on territorial dynamics and theory development. This paper addresses this aspect of the problem by introducing a theoretical and methodological framework for the analysis of the interrelationship between land uses. The analysis attempts to determine to what extent the functional land use in a city can be considered an ordered pattern. The order sought does not rely on purely spatial configurations, but on the correlation of transportation and land use. The first section of this paper focuses on theoretical considerations. It stresses the fact that conventional approaches do not apply in the present context. It then suggests an alternative based on areas of influence and measured in terms of level of attractance of land uses. The second describes a procedure based on this alternative following the remarkable contribution of Hanjoul, Beguin and Thill. An application of this procedure to the analysis of Shanghai is then examined. Finally, an evaluation of the strategies for optimizing the interrelationship between land uses is presented. The paper concludes with a possible research agenda.     

Direct analysis of the perceived importance of attributes of reliability of travel modes in urban travel

Reliability of travel modes was found to be the most important characteristic of transportation systems in several attitudinal investigations of individual travel behavior. This paper represents the first part of a research effort aimed at gaining a better understanding of the characteristics of reliability of transportation modes in urban travel. In this research, reliability characteristics are identified; their importance relative to each other is assessed, and an insight into possible structure of an objective reliability index is discussed. The research is based on perceived values of reliability, which were identified through a large attitudinal survey conducted in the Chicago metropolitan area.