某商用车散热器面罩开裂分析与改进

为解决散热器面罩开裂问题,提出了焊点优化方案和散热器面罩加强板外置/加强板内置方案,并进行了模块化设计,制定了2组改进措施。有限元分析结果表明:2种改进措施与原状态相比,均有良好应力改善效果,满足应力要求。     

Eliminator防水体系及浇注式沥青混凝士在无锡S342钢箱梁桥面施工中的应用

该文介绍了Eliminator防水体系及浇注式沥青混凝土应用于无锡S342主线西互通钢箱梁桥面铺装底层的情况,详细阐述了铺装方案及施工过程,根据已完工程的施工经验,并结合无锡S342主线西互通钢箱梁桥的实际情况,总结了施工工艺.     

Impacts of urban built environment on empty taxi trips using limited geolocation data

This study identifies the determinants of the empty taxi trip duration (ETTD) by combining three high-resolution databases—geolocation data in New York City, geodatabase of urban planning data, and transportation facilities data. Considering the nature of duration data, hazard-based duration model is proposed to explore the relationships between causal factors and ETTD, coupling with three variations of baseline hazard distribution, i.e., Weibull distribution with heterogeneity, Weibull distribution, and log-logistic. Furthermore, the likelihood ratio test is presented to implement comparisons of three baseline hazard distributions, as well as spatial and temporal transferability of causal factors. The results show significant complementary effects by subway system and competitive effects by city bus and bicycling system, as well as significant impacts of trip length, airport trip, average annual income, and employment rate. Urban built environment, for instance, density of road, public facilities, and recreational sites and ratio of green space, has various impacts on ETTD. The elasticity estimations confirm significant spatial and temporal heterogeneity in impacts on ETTD. In addition, the analysis on elasticity also reveals the considerable impacts of severe traffic congestion on ETTD within Manhattan. The modeling can assist stakeholders in understanding empty taxi movements and measuring taxi system efficiency in urban areas.     

基于卷积和递归神经网络融合的交通状态指数预测

为提高交通状态指数预测精度,方便市民出行规划和提高相关机构管理预见性,创新研究了基于卷积和递归神经网络融合的交通状态指数预测模型.模型将卷积网络和递归网络进行了融合,由卷积神经网络层和递归神经网络层组成.该模型中的卷积网络能自动提取重要影响因子,同时递归网络能捕捉到前后时序特征,结果显示,得到的融合模型在交通状态指数预...     

A programmable calculation procedure for number of traffic conflict points at highway intersections

Traffic movement conflict points at intersections are the points at which traffic movements intersect (including crossing, merging, and diverging). Numbers and distribution of different types of conflict points are used to evaluate intersection access management designs and safety performance. Traditionally, the determination of the numbers of conflict points for different traffic movements is based on manual methods, which causes the difficulty for computerized procedures to evaluate safety performance of different access management designs. Sometimes, a programmable calculation procedure may provide more effective solutions as compared with manual methods. This paper presents a programmable calculation procedure for the determination of the numbers of conflict points, which could be used as a basis for a computerized procedure. Concepts of virtual movement lanes and intersection quadrants are introduced to specify types of intersections, traffic lane configurations, and traffic movement regulations. Calculation models, based on such concepts, for traffic movement conflict points at signalized and unsignalized intersections can be obtained. In support of the procedure, case studies are presented in the paper. The procedure presented in the paper can be programmed into a computer program for the purpose of a computerized evaluation of intersection safety and design performance of different access management or control approaches. Copyright © 2012 John Wiley & Sons, Ltd.     

新型减隔震支座的研究

普通桥梁减隔震支座可能发生翻滚失稳,并且存在肥大等弊端.针对这些问题,提出一种新型减隔震支座,它是由聚四氟乙烯滑板、肘块、支柱和高弹性阻尼橡胶体通过连杆连接而成.通过理论推导和分析,得出了新型减隔震支座的等价刚度和等价阻尼比的计算式和系统周期图示.应用大型专业分析软件ANSYS,对实际桥梁进行建模分析,结果表明,新型减震支座的应用,可以使桥梁的减隔震效果达到50%以上.     

关联道路试验的轴耦合道路模拟试验关键技术研究

轴耦合道路模拟试验技术是源于道路试验的先进技术.首先梳理了两者的原理及关系;提出了道路试验与轴耦合道路模拟试验的主要关联路线;提出了道路模拟试验有效性的研究方法;提出了基于疲劳损伤的道路模拟试验可信度分析方法;总结实际试验关联结果,证明道路模拟试验的精准性.     

基于灰色关联度分析的模拟电路故障诊断

一般情况下,模拟电路中存在着元件容差,使得电路的测量数据存在着不确定的信息,增加了故障诊断的难度。而灰色关联度分析在处理此种不确定信息方面有着独到的优势,可以代替传统故障字典法单纯采用样本距离作为故障的分类指标方法进行故障诊断。因此,灰色关联度分析非常适合于容差模拟电路的故障诊断。     

汽车动力总成弯曲振动应力响应及其激励灵敏度分析

本文利用文献（５）建立的汽车动力总成弯曲有限元分析模型，计算分析离合器壳的动应力响应，并考察了动应力关于不平衡质量位置的灵敏度，对计算分析进行了实验验证。     

中美教育比较浅析

将中国与美国教育体制、教育方法等方面进行比较,对中国教育现在存在的一些问题,提出了自己的看法.