基于3D技术的转辙机仿真操作平台设计与实现

为解决当前高等院校在铁路信号专业教学中缺乏信号设备进行实物展示的问题,以3D MAX和Unity 3D为开发平台,借助TCP/IP (Transmission Control Protocol/Internet Protocol)协议,设计转辙机仿真操作平台,实现车站现实环境仿真及转辙机动作的3D展示,从不同视角展现转辙机状态转换过程,达到模拟现实的效果。该平台已在西南交通大学实验室投入使用,满足教学实践需求。     

Continuous approximation models for mixed load school bus routing

School bus routing is a complex and expensive transportation problem for many public school districts. Typical school bus routes serve a single school, but mixed load school bus routes carry students for more than one school at the same time. A mixed load policy reduces the number of stops and distance to pick up and drop off children, but it can increase travel distance by visiting multiple schools. This paper provides a general strategic analysis using continuous approximation models to assess the conditions under which mixed loading is likely to be beneficial. We also present a case study for a semi-rural Missouri school district to illustrate the application of the models in practice. Results show that mixed load routing is more beneficial for larger districts, when a large percentage of bus stops are shared by students of different schools, and when schools are closer together.     

Optimization of headways with stop‐skipping control: a case study of bus rapid transit system

Bus rapid transit system is designed to provide high‐quality and cost‐efficient passenger transportation services. In order to achieve this design objective, effective scheduling strategies are required. This research aims at improving the operation efficiency and service quality of a BRT system through integrated optimization of its service headways and stop‐skipping strategy. Based on cost analysis for both passengers and operation agencies, an optimization model is established. A genetic algorithms based algorithm and an application‐oriented solution method are developed. Beijing BRT Line 2 has been chosen as a case study, and the effectiveness of the optimal headways with stop‐skipping services under different demand levels has been analyzed. The results has shown that, at a certain demand level, the proposed operating strategy can be most advantageous for passengers with an accepted increase of operating costs, under which the optimum headway is between 3.5 and 5.5 min for stop‐skipping services during the morning peak hour depending on the demand with the provision of stop‐skipping services. The effectiveness of the optimal headways with stop‐skipping services is compared with those of existing headways and optimal headways without stop‐skipping services. The results show that operating strategies under the optimal headways with stop‐skipping services outperforms the other two operating strategies with respect to total costs and in‐vehicle time for passengers. Copyright © 2014 John Wiley & Sons, Ltd.     

安全视角下我国校车集约运营模式探讨

当前我国校车服务尚处于粗放式运营阶段，还存在运营效率低、国家财政投入缺口大、安全事故频出、服务满意度差等问题。鉴于此，基于安全的视角，借鉴运输规模经济理论与企业集约化经营理论，提出校车集约运营模式，与当前校车运营模式相比，其具有成本投入少、服务标准化程度高、政府易监管、有利于缓解学校周边交通拥堵、有利培养学生公平意识、绿色环保等优势。进而提出了校车集约运营的5类模式：校车专营模式，城市公交模式，农村县际、乡际、村际班车模式，拼车模式，混合模式，系统阐述了5类模式的集约方法，最后在政策层面、技术层面就如何在我国推广校车集约运营提出了相应的对策。     

交─直─交传动机车机械部分的设计特点

交－直－交传动技术应用于机车动车具有明显的优点，７０年代以来被世界各国铁路广泛采用，已形成一种趋势．本文简要地叙述其优势，并就减轻机车重量、高粘着、高动力学性能和改善通风等机械部分的设计特点作了介绍．     

RV传动输出机构的刚性误差分析

ＲＶ传动中摆线轮与输出盘之间的输出机构是同三个双曲柄平行四边形机构组成的封闭式单自由度并联机构，由于构件长度制造偏差和铰链运动副中的径向间隙，摆线与输出盘之间会产生相对位置误差，这一误差数值还与构件的弹性有关。作为基础。本仅在刚体这的范畴内研究这一的数据，提出了关于一般四杆铰接机构刚性误差的计算模型，然后应用于平行四边形机构和ＲＶ传动的输出机构，最后给出数值计算例证。     

基于PCI总线智能通讯系统的设计与实现

描述了一种基于PCI总线的实时智能通讯系统的设计以及实现，应用了嵌入式微控制器AMl86CC以及PCI目标设备接口芯片AMCCS5920。并设计相关逻辑控制上位机(PCI总线)与下位机(局部总线)的数据交换以及外部通信，充分利用了PCI总线的高效能和嵌入式通讯控制器的强大功能，并设计出基于VxWorks的配套设备驱动程序，使系统更加完善。     

基于C/S模式的职称评审系统的研究

遵循海军专业技术职务评审工作的要求，对实现海军专业技术职务评审辅助系统中的一些关键技术进行了研究，然后列出了一些实际开发中所遇到的问题并给出了解决方案。     

A review of the effect of a/W ratio on fracture toughness (Ⅲ)——theoretical analysis

In partⅠandⅡof this series, experimental investigation in both EPFM and LEFM had been discussed. In this part, further theoretical analysis is given. The theoretical development of Two Parameter Fracture Mechanics by Hancock etc, has rationalized our experimental results. This method can be applied to engineering practice, and will allow the advantage of enhanced toughness for specimens with low levels of constraint to be taken into account for defect assessment.     

ZS6900EV纯电动城市公交客车

文章主要介绍了ZS6900EV纯电动城市公交客车的结构参数、动力性能及其基本工作原理、主要部件和测试结果.