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针对模糊Petri网在故障诊断中缺乏较强的自学习能力的缺点,将人工神经网络引入到模糊Petri网中,定义一种模糊神经Petri网,应用于天然气长输管道故障诊断,对过程中的故障诊断进行建模,通过分析说明该方法的可行性。 相似文献
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本文分析了柴油机常见故障及影响因素,总结了现代柴油机故障诊断技术中常用的基于振动信号的时频分析方法、瞬时速度波动法、人工神经网络法、灰色系统理论诊断法和专家诊断法的原理及其特点,最后指明今后研究工作的重点和方向。 相似文献
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行波定位法常用于雷达、声纳、无线电测量和其他电磁测量应用中,对于提高轨道交通运行的安全及通信效率具有积极作用。因此,提出基于行波定位法的轨道交通设备多因素故障诊断研究。从某地铁交通设备故障实例出发,分析基于行波定位法的轨道交通设备多因素故障诊断方法,解释行波定位故障的诊断过程,详细阐述故障行波产生、故障行波算法、行波相位变换及判定故障具体位置的方法,得出应用行波定位法可精准测试轨道交通设备多因素故障的结论。以期为轨道交通设备维护工作人员精准定位故障设备位置提供辅助,提升其工作效率,以便高效完成对轨道交通设备故障的维修和更换工作。 相似文献
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液压系统油液污染度模糊故障诊断方法 总被引:2,自引:0,他引:2
文章利用模糊数学在描述油液污染与机器磨损的模糊关系中的优势,建立了模糊故障诊断的数学模型,并在现有的污染度模糊故障诊断的基础上,通过故障征兆空间的压缩和重构,大大减少了计算量,提高了故障诊断的效率。 相似文献
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研究暖通空调系统故障诊断技术运用对策,需了解其诊断现状,分析不同故障的基本特征、类型等,以此来提出相关诊断技术,如系统模型诊断法、直接诊断法、大数据诊断法等,不同诊断方法有着不同的适用区间。因此,需结合暖通空调系统的实际特征、应用环境、各类故障发生频次等选择最优故障诊断技术,制定诊断方案,如此才能发挥更大效能。 相似文献
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通过维修实例,阐述对于电控发动机的故障,汽车维修人员应根据两次调取的故障代码和路试结果作为故障诊断的重要依据,不可仅靠调出的故障代码来决定电控系统的故障所在,因为有些电控元件的故障信息不能通过电控参数反映给ECU. 相似文献
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管网在介质输送总中总会发生故障的,倘若故障刚发生时就被发现,及时采取措施不致于成大的经济损失。本文就从这个角度阐述微机进行管网故障诊断的方法。 相似文献
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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。 相似文献
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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. 相似文献
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《Transportation Research Part A: General》1991,25(6):407-418
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. 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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Joseph N. Prashker 《Transportation》1979,8(4):329-346
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. 相似文献
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