竖向荷载和弹条扣压力对WJ-8扣件纵向阻力影响试验研究

扣件阻力是无缝线路的关键参数。为研究竖向荷载和弹条扣压力(扭矩)对扣件纵向阻力的影响,以WJ-8型扣件为研究对象,开展不同竖向荷载和扭矩下扣件纵向阻力-位移试验,得到不同工况下扣件纵向阻力-位移变化特征。试验结果表明:(1)扣件滑移之前,扣件纵向阻力-位移关系受竖向荷载的影响不显著;(2)不同竖向荷载和扭矩下扣件纵向阻力-位移关系可用幂指函数进行拟合;(3)扣件滑移阻力随竖向荷载的增加而线性递增,且竖向荷载越大,扣件滑移阻力随扭矩的增加而增加的幅度减小;(4)不同工况下扣件纵向阻力-位移曲线存在滞回效应特性,滞回曲线可采用幂指数型函数拟合得到。     

机动性管理措施的质量管理——促进城市交通可持续发展的方案

机动性管理一直是欧洲促进和实现城市交通可持续发展普遍采用的方法。然而,机动性管理政策和措施在欧洲城市的发展未能遵循一个有组织且持续的方法,用以规划、设计、应用和评估综合机动性管理系统。在这一背景下,基于质量管理原则,提出一个促进城市系统地发展及实施机动性管理规划和措施的方案。这一机动性管理的质量管理方案（QMSMM）由4个主要组成成分整合而成,包括政策制定、规划、实施及监测和评估。详细阐述了QMSMM的结构、组成成分和要素,以及支撑评估该方案与城市的适用性和相容性的过程。除此之外,对QMSMM在比利时科特赖克市机动性管理计划中的应用开展实证研究。     

A cell-based logit-opportunity taxi customer-search model

This paper proposes a cell-based model to predict local customer-search movements of vacant taxi drivers, which incorporates the modeling principles of the logit-based search model and the intervening opportunity model. The local customer-search movements were extracted from the global positioning system data of 460 Hong Kong urban taxis and inputted into a cell-based taxi operating network to calibrate the model and validate the modeling concepts. The model results reveal that the taxi drivers’ local search decisions are significantly affected by the (cumulative) probability of successfully picking up a customer along the search route, and that the drivers do not search their customers under the random walk principle. The proposed model helps predict the effects of the implementation of the policies in adjusting the taxi fleet size and the changes in passenger demand on the customer-search distance and time of taxi drivers.     

An integrated analysis of workers’ physically active activity and active travel choice behavior

Using Texas add-on sample data from the 2009 National Household Travel Survey, this study examines adult workers’ daily active choice decisions in the context of physical activity and attendant health benefits. The study looked at workers’ two choice behaviors: active activity and active travel. The first choice behavior, active activity, is developed as an ordered-response model based on the number of physically active recreational activities pursued during the workday. The second choice behavior, active travel, is developed as a binary-response model that examines workers’ active travel choices—whether or not the worker used any active mode of travel during the same workday. The study improves the understanding and knowledge of observed factors influencing workers’ physically active activity-travel behavior. The study also provides several observations regarding the role (and constraints) of employment in individuals’ active choices. Using a flexible copula modeling methodology, we explore the true correlation (or dependence) between the two behavior choices that could occur due to the presence of unobserved factors, suggesting a simultaneously low or simultaneously high propensity for being physically active across workers. The study findings suggest that transportation and public health policy makers can mutually benefit from encouraging workers to be physically active (from an activity and/or travel perspective). Overall, the study draws attention to the integrated nature of the public health and transportation fields, thereby providing a distinct view of active/inactive choice behavior. To our knowledge, this is the first study exploring a rich variety of components for workers’ active activity-travel behavior through a robust copula approach.     

基于多维数据库的联机处理技术在装备维修费管理中的应用

论文以装备维修费分析为应用背景,按照需求分析、概念设计、逻辑建模、系统实现的软件工程过程,对基于多维数据库的联机分析处理（OLAP）技术及其实现方法进行了研究.     

隧道波纹钢板套衬接头抗弯性能有限元分析

为进一步探讨隧道波纹钢套衬结构纵向连接接头的安全性和适用性问题，对不同型号拼装式波纹钢板纵向接头抗弯力学性能进行研究，选取200 mm×55 mm、300 mm×110 mm和400 mm×150 mm 3种型号波纹钢板试件进行接头抗弯数值模拟。共设计12种工况，对比不同规格螺栓的应力分布规律、变形破坏形式及不同螺栓预紧力条件下的法兰板极限承载力及变形破坏特征，就螺栓应力、跨中挠度、极限承载力、法兰板接缝张开量及塑性破坏等方面进行深入分析。研究结果表明： 1）螺栓主要受拉弯变形，内侧螺栓较外侧螺栓受力更大，率先达到屈服状态； 2）接头薄弱点主要在于法兰板，其更容易发生变形破坏； 3）螺栓预紧力对波纹钢板的极限承载力、跨中挠度及接缝张开量均有一定的影响； 4）大波形波纹钢板极限抗弯承载能力约为深波形和中波形的1.36倍和1.67倍。     

基于高速公路流水数据的通勤车辆特征研究

随着居民利用高速公路进行通勤出行车辆的增加，高速公路缓行和交通拥堵等问题时有发生，特别是在重大节假日期间.目前，解决上述交通问题的主要方法是交通需求管理措施，而实现有针对性的交通需求管理需要对高速公路收费流水数据进行精确的挖掘分析，掌握车辆在高速公路上的运行状态与时空分布特征.本文基于高速公路收费流水数据，借助 K-means++聚类方法识别使用高速公路日常通勤的车辆，进一步分析通勤车辆的出行时空分布特征.从通勤出行的角度，挖掘城市通勤快速出行廊道分布，研究高速公路网与城市道路网络的关系，对提高交通系统效率和缓解交通问题具有重要的意义.     

产品数据管理系统在离散型制造企业中的应用

为了解决多品种、小批量的生产模式为离散型制造企业带来的诸多管理难题,提出通过建设信息化管理平台帮助企业提升管理水平。阐述了中交西筑公司建设“产品数据管理系统”(一期)的实际建设内容及应用情况,为即将建设信息化管理平台的制造企业提供参考。应用效果表明,该产品数据管理系统可以降低生产成本,提高效率。     

大数据视角下市政道路工程绩效评价体系探讨

通过对城市道路全寿命周期进行绩效评价,有利于提高建设单位综合管理水平,但目前暂没有一套成熟的市政道路工程的绩效评价体系.基于大数据技术,以其他相关领域工程绩效评价体系为参考,对现有工程绩效评价体系的不足之处进行了总结,对建立一个客观、准确、适用性广、可操作性强的市政道路全过程绩效评价体系提出了初步构想,并就确保体系有效性问题提出了需要关注的问题及解决思路.