渐开线斜齿行星轮系振动特性的模态分析

风力发电机增速机构中行星轮系的振动是影响风机寿命的主要因素,通过利用PRO/E的参数功能对斜齿行星轮系进行参数化设计与建模,并对模型进行精确装配,以有限元理论为基础,对其进行整体模态分析,计算得出固有频率及对应的振型。对计算结果进行分析,可以在设计斜齿行星轮系过程中避开共振频率区域,从而避免共振对机构产生的破坏影响,提高行星传动机构的使用寿命,为斜齿行星齿轮机构的设计提供了理论依据,同时为对其进行动态响应分析奠定了基础。     

基于模型的列车自动防护系统软件开发

列车自动防护系统是保证列车运行安全的安全苛求系统,该系统功能繁多、逻辑复杂、开发难度大。为此,提出一种基于模型的软件开发方法,采用接口模型、状态模型和控制流模型描述该系统软件的功能,实现应用软件的开发。仿真测试结果表明,该方法能有效简化功能逻辑,降低开发难度,减少人为错误和故障的引入。     

基于通信的列车自动监控系统平台设计与实现

针对基于无线通信的列车控制系统(CBTC)的需求和现状,对其原理及特点进行深入分析,特别是对移动闭塞原理的分析,并利用组件化程序设计思想与线路拓扑结构,提出并设计了一种基于CBTC的列车自动监控(ATS)系统交互式平台,并交付ATS仿真运营框架对站场运行图进行调用.     

Sentiment analysis of Chinese microblogging based on sentiment ontology: a case study of ‘7.23 Wenzhou Train Collision’

Sentiment analysis of microblogging texts can facilitate both organisations’ public opinion monitoring and governments’ response strategies development. Nevertheless, most of the existing analysis methods are conducted on Twitter, lacking of sentiment analysis of Chinese microblogging (Weibo), and they generally rely on a large number of manually annotated training or machine learning to perform sentiment classification, yielding with difficulties in application. This paper addresses these problems and employs a sentiment ontology model to examine sentiment analysis of Chinese microblogging. We conduct a sentiment analysis of all public microblogging posts about ‘7.23 Wenzhou Train Collision’ broadcasted by Sina microblogging users between 23 July and 1 August 2011. For every day in this time period, we first extract eight dimensions of sentiment (expect, joy, love, surprise, anxiety, sorrow, angry, and hate), and then build fuzzy sentiment ontology based on HowNet and semantic similarity for sentiment analysis; we also establish computing methods of influence and sentiment of microblogging texts; and we finally explore the change of public sentiment after ‘7.23 Wenzhou Train Collision’. The results show that the established sentiment analysis method has excellent application, and the change of different emotional values can reflect the success or failure of guiding the public opinion by the government.     

智能化列车管贯通状态监测仪的设计与实现

文章介绍了以８９Ｃ５１为核心所组成的智能化列车管贯通状态监测的工程设计与实现，它能在机车的正常运行中自动显示出列车管内压力和差奈的动态参数。并能实现系统的实时校准和怕误差修正。     

The simulation of unsteady aerodynamic cross wind forces on trains

This paper describes an investigation of the effect of cross winds on train dynamic systems. It considers the nature of the fluctuating cross wind and how such cross winds produce fluctuating forces. A simple method for calculating the wind time history at the position of a moving vehicle is firstly set out, that is computationally much less expensive than existing methods. The concepts of aerodynamic admittance and weighting function are then introduced, and methods outlined for parameterising experimental values of aerodynamic admittance and obtaining simple closed form weighting function solutions from these expressions. The use of the weighting function in obtaining unsteady force time histories is then set out. It is shown that different formulations of this method are necessary for stationary and moving vehicles. A statistical analysis of the results produced by this method is then presented, which compares the results to those of simple quasi-steady calculations. An appendix describes how the cross wind forces develop in a variety of different idealised gust shapes. It is concluded that, if the dynamic phenomenon of interest has a time period of <0.5 s, then a simulation of the type described in this paper is required, as the quasi-steady approach produces unduly conservative force values. If, however, the time period of the dynamic phenomenon is of the order of 1 s or more, then quasi-steady calculations are more than adequate, particularly at the higher vehicle speeds.     

地铁深埋长隧道排烟方案研究

为解决地铁深埋长隧道内事故工况下列车追踪问题,以工程实际情况为例,采用计算机模拟的方法,对地铁深埋长隧道分别采用中间风井、轨顶风道与全部采用射流风机三种通风方案分别进行建模计算分析,结合线路埋深、行车密度、隧道断面、疏散安全等各方面因素,充分分析与阐述了各种方案的特点以及存在的问题。     

选煤厂投建火车快速定量装车系统的可行性研究

太原选煤厂重介技术改造后，装车系统已经严重地制约了生产能力的提高，提出投建火车快速定量装车系统的可行性，满足生产能力的需要，取得较好的效益。     

建筑设计中新与旧的关系探讨

本文通过具体的实例,探讨了处理建筑设计中新和旧关系的三种思路。建筑师只有把握好新与旧矛盾的主次关系,才能为设计的展开打下坚实的基础。     

A wave signature based method for the prediction of pressure transients in railway tunnels

The unsteady aerodynamic effects in railway tunnels are generally analyzed by quasi one-dimensional numerical simulations which can give the effects of the pressure waves encountered in the tunnels with a low CPU cost. In the present work, a new method for predicting the evolution of the pressure in the tunnel is presented. This method, based on the signature of the pressure waves during their propagation, requires lower computational efforts, gives results with a precision equivalent to those obtained by conventional methods, and permits to investigate more complex situations of train circulation in simple tunnel. The simulation of the tunnel length influence on the pressure changes permits to define a very short, a short and a long tunnel. The crossing of two High speed trains in tunnel is simulated with different delays in the time entry of the trains, and it is shown that the maximum pressure change in the tunnel or on the trains is function of this time shift.