关于城市道路潮汐车道的设置研究

针对城市道路早晚高峰单向拥堵难题,分别对已建和新建存在潮汐车流的道路进行了分析,对设置潮汐车道的条件进行了论证,并对潮汐车道道路的管理进行了研究。通过论证分析,明确了已建道路和新建道路设置潮汐车道的条件及设置潮汐车道要解决的问题,对设置潮汐车道的道路提出了管理措施。     

�źſ��ƽ������תר�ó��� ͣ�����Ż���Ƶķ����о�

基于对左转专用车道停车线的研究,分析了停车线的位置与相位绿灯间隔时间和车道饱和流量这两个交叉口通行能力关键影响因素的关系在保障交又口车辆通行安全的前提下,以交叉口通行能力最大为目标,建立以左转车道停车线位置与直行车道停车线位置之间距离为基本参数的数学模型,并提出了相应的解法,最后,通过具体的交又口实例分析,求解出了左转停车线的最佳位置,证明该模型具有很好的实用性.     

Estimation of cost and CO2 emissions with a sustainable cross-border supply chain in the automobile industry: A case study of Thailand and neighboring countries

CO₂ emissions are increasing because of the growth in the cross-border supply chain, which is leading the locations of assembly plants and suppliers to spread across a wider area. Given that one passenger vehicle needs more than 20,000 components and parts, the automobile industry exploits the cross-border supply chain. Recently, the free cross-border movement of people, goods, capital, and information has accelerated in Asia. Therefore, a sustainable cross-border supply chain is required to reduce both CO₂ emissions and cost. This study estimates total CO₂ emissions per vehicle including production and transportation processes in Thailand and neighboring countries and the change in CO₂ emissions based on future policy scenarios that consider the automobile market and locational conditions in 2030. The results show that locating production close to the place of consumption and the electricity emissions factors in each country should be considered.     

What determines rail transit passenger volume? Implications for transit oriented development planning

Transit oriented development (TOD) has been an important topic for urban transportation planning research and practice. This paper is aimed at empirically examining the effect of rail transit station-based TOD on daily station passenger volume. Using integrated circuit (IC) card data on metro passenger volumes and cellular signaling data on the spatial distribution of human activities in Shanghai, the research identifies variations in ridership among rail transit stations. Then, regression analysis is performed using passenger volume in each station as the dependent variable. Explanatory variables include station area employment and population, residents’ commuting distances, metro network accessibility, status as interchange station, and coupling with commercial activity centers. The main findings are: (1) Passenger volume is positively associated with employment density and residents’ commuting distance around station; (2) stations with earlier opening dates and serving as transfer nodes tend to have positive association with passenger volumes; (3) metro stations better integrated with nearby commercial development tend to have larger passenger volumes. Several implications are drawn for TOD planning: (1) TOD planning should be integrated with rail transit network planning; (2) location of metro stations should be coupled with commercial development; (3) high employment densities should be especially encouraged as a key TOD feature; and (4) interchange stations should be more strategically positioned in the planning for rail transit network.     

PEG/SiO_2相变颗粒对沥青混合料储热及高温性能的影响

利用相变材料物相转变时吸收或释放大量热量而本身温度保持不变的特性,用溶胶-凝胶法制备PEG/Si O2相变颗粒,并将其以等体积替代法替代粒径小于0.6 mm的细集料应用于沥青混合料中。考察了PEG/Si O2相变颗粒对4种不同级配的沥青混合料温度敏感性及高温稳定性的影响。结果表明,PEG/Si O2相变颗粒的掺入可降低沥青混合料的温度敏感性,并且掺量越大效果越明显,当其掺量达到5%时,可在自然光照条件下降温5℃以上,而级配对沥青混合料的温度敏感性影响不明显。PEG/Si O2相变颗粒对沥青混合料的高温稳定性影响与相变颗粒的掺量及沥青混合料的级配类型有关。相变颗粒的掺入在降低沥青混合料最高温度的同时,可降低沥青混合料发生高温车辙病害的可能性。     

基于云服务的交通量计算系统的设计

为了提高交通量数据采集与计算能力,基于云服务设计了一个交通量计算系统,集中处理全市交通量数据.应用了Windows Mobile智能设备开发技术编写了手机端交通量计数器程序,通过3G网络实现了交通量原始数据的上传.在云服务中心,应用了Excel VBA二次开发技术生成了各种统计图表,调查员在工作中,随时可下载统计图,了解交叉口的实时交通流量、流向等数据.实践证明,该交通量计算系统扩展性良好,能应对大城市交通量计算需求,能够推进智慧交通、智慧城市的建设.     

基于UML技术的精益船舶生产计划系统的设计

摘 要：精益船舶生产计划是船厂组织精益生产活动的直接依据,其系统开发与应用有迫切需求。由于精益船舶生产计划管理流程复杂,传统的结构化设计方法难以完成系统的分析与设计。本文介绍应用UML技术进行复杂的船舶生产计划系统分析与设计。首先,分析精益船舶生产计划的特征,提炼系统的功能需求;然后,结合精益船舶生产计划管理的业务流程,划分系统功能模块并理清系统工作流;最后,对系统进行静态建模和动态建模,完成整个系统的设计。     

基于基础IE的D310车身生产线改进

提出了D310车身生产线的改善方案。运用秒表测时方法测定流水线各工位的作业时间,找出影响流水线生产能力的瓶颈工位,运用"5W1H"提问技术和工作研究方法,分析流水线在设备能力、定员、任务分配、工艺内容及流水线布局等方面存在的问题。应用基础IE的方法及流水线平整理论缩短D310车身生产线的制造周期,实践证明改进效果明显。     

基于Matlab的铁路内部因素与货运量的灰色关联分析

随着货运改革的深入进行,铁路货运量已经呈现增长趋势。但是除了运营模式的因素,铁路内部影响货运量的因素也有很多。从铁路内部因素中选取一系列铁路运输统计指标,运用Matlab编制程序对选取的指标进行灰色关联度分析,根据灰色关联度的大小判断指标与货运量的关系程度是否密切,总结出与货运量关系密切的几个指标并提出相关建议,为货运量分析和货运改革以及相关决策奠定基础。     

螺旋箍筋约束高强混凝土柱轴心受压性能试验研究

为探究螺旋箍筋约束高强混凝土柱的轴心受压性能,开展了42根螺旋箍筋约束高强混凝土圆柱的轴压试验,研究了混凝土标准立方体抗压强度(58.0~90.6 MPa)、箍筋屈服强度(480~1 219 MPa)、体积配箍率(1.00%~1.60%)与箍筋间距(45~80 mm)对螺旋箍筋约束混凝土柱受压承载力和变形能力的影响。试验结果表明:箍筋约束混凝土在达到峰值压应力时,约束箍筋可能达不到屈服;约束箍筋的强度和体积配箍率相同时,随着高强混凝土强度的增高,约束混凝土达到峰值压应力时箍筋的拉应变减小;混凝土轴心抗压强度、箍筋屈服强度相同时,随着体积配箍率的提高,约束混凝土峰值压应变增大,相应的横向应变也随之增大,箍筋拉应变也增大。基于试验结果,考察了峰值压应力下箍筋拉应变与体积配箍率、混凝土强度、箍筋屈服强度和箍筋间距之间的关系,建立了峰值压应力下约束箍筋拉应变计算公式。拟合得到了约束混凝土峰值压应力f_cc、峰值压应变ε_cc、下降段曲线的特征参数(峰值压应力后85%峰值应力下的轴向压应变ε_c85、50%峰值压应力的轴向压应变ε_c50)的计算公式。给出了考虑体积配箍率、混凝土轴心抗压强度、箍筋间距和箍筋屈服强度影响的箍筋约束高强混凝土的轴心受压应力-应变关系模型。