Spatio-temporal analysis of rail station ridership determinants in the built environment

The development of new routes and stations, as well as changes in land use, can have significant impacts on public transit ridership. Thus, transport departments and governments should seek to determine the level and spatio-temporal dependency of these impacts with the aim of adjusting services or improving planning. However, existing studies primarily focus on predicting ridership, and pay relatively little attention to analyzing the determinants of ridership from temporal and spatial perspectives. Consequently, no comprehensive cognition of the spatio-temporal relationship between station ridership and the built environment can be obtained from previous models, which makes them unable to facilitate the optimization of transportation demands and services. To rectify this problem, we have employed a Bayesian negative binomial regression model to identify the significant impact factors associated with entry/exit ridership at different periods of the day. Based on this model, we formulated geographically weighted models to analyze the spatial dependency of these impacts over different periods. The spatio-temporal relationship between station ridership and the built environment was analyzed using data from Beijing. The results reveal that the temporal impacts of most ridership determinants are related to the passenger trip patterns. Furthermore, the spatial impacts correspond with the determinants’ spatial distribution, and the results give some implications on urban and transportation planning. This analysis gives a common analytical framework analyzing impacts of urban characteristics on ridership, and extending researches on how we capture the impacts of urban and other factors on ridership from a comprehensive perspective.

     

重载运输战略装车域车流组合方案优化

为研究铁路重载运输装车端车流组织优化问题,首先分析了基于重载运输的战略装车域车流组织过程,将其按货源供给水平及运输组织方式划分为战略装车点、装车区及装车域3个层次,根据装车域车流以单元式重载列车和组合式重载列车进行组织的特征,以组合列车总组合时间最小化为目标,考虑年目标运量、线路能力、装车点(区)装车能力等约束条件,引入组合映射关系式表示组合站的车流接续关系,构建了符合我国重载线路装车域车流组织特征的车流组合方案优化模型,并设计了启发式算法进行求解.算例结果表明:根据论文提出的优化方法,可获得3种等价的组合方案,其中算例优化方案2与现场车流组织方案相符,其余两种等价组织方案的组合内容不同,但总时间消耗相同.      

基于Web的货车检修工序监测系统的研制

介绍了铁路货车检修工序进展监控与管理软件的设计.系统通过Web服务器的串口所连接的无线通信模块与现场的无线手持机通信.主机通过轮询方式查询手持机发送的作业进展信息,利用多线程协调完成通信信息的获取与分析.同时,系统采用B/S模式在浏览器页面能对检修工序进展进行实时监视.在Web服务器端,利用Spring任务定时实现每天工作的启停,以及用Spring编写REST风格的Web服务.在浏览器端,利用AJAX技术实现对Web服务的访问,以及将显示结果在页面上动态显示.Web服务通过Json变换向浏览器传递对象消息.     

Effects of length and location of steel corrosion on the behavior and load capacity of reinforced concrete columns

The effects of length and location of the steel corrosion on the structural behavior and load capacity of reinforced concrete (RC) columns have been investigated. Results of the accelerated corrosion process and eccentric load test are presented in detail. Effects of the location of the partial length, the corrosion level within partial length and the asymmetrical deterioration of the concrete section on the mechanical behavior and load capacity of corroded RC columns are discussed. It is found that the mechanical behavior and load carrying capacity of corroded RC columns are simultaneously affected by the above mentioned factors. For the corroded RC columns with large eccentricity, a higher corrosion level in the tensile corroded length and a greater asymmetrical deterioration of the concrete section can result in less ductile behavior and larger load reduction of the column; while for the corroded RC columns with small eccentricity, the less ductile behavior and the larger load reduction of the column may result from the higher corrosion level in the compressive corroded length and the greater asymmetrical deterioration of the concrete section.     

上海市出租汽车出行时空分布规律研究

为测定大样本视角下出租汽车出行时空规律,采用探索性空间数据分析（ESDA）技术进行相关研究。从上海市出租汽车调度系统的GPS数据提取单个运营日9921辆出租汽车的OD样本,按街道和时段统计出租汽车OD的时空发生量,定义并计算各区域各时段的载客空间密度指标,运用ESDA技术分时段计算、分析全局和局部莫伦值（Moran＇s I）。全局分析结果表明,上海市出租汽车出行在全局分布上具有较强的空间正自相关性,这与城市中心商业区高度集中的活动分布有关。局部分析结果表明,上海市出租汽车出行分布呈＂句＂字形聚集结构。全局结构和局部结构在时间序列上变化较小,表明上海市出租汽车出行分布的时空结构明显且稳定。     

广州市轨道交通枢纽用地开发模式研究

如何确定城市轨道交通枢纽的开发模式以获取最大的效益已成为对其进行合理开发需要探讨的重要课题。首先指出广州市现有轨道交通枢纽用地规划及开发模式不佳,缺乏明确的开发导向。在明确轨道交通枢纽范围和分类的基础上,分析居住、商业、办公三类用地在吸引客流、服务时间、土地增值方面的特性,提出广州市各类轨道交通枢纽用地开发的主导功能。同时,通过建立轨道交通枢纽用地开发投资平衡模型,给出广州市轨道交通枢纽用地开发强度建议。最后,从规划设计流程、建设模式、开发机制三方面提出后续研究方向。     

广州市现代综合交通枢纽体系规划研究

为解决城市规模快速增长带来的交通运输低效问题,积极转变交通发展方式、加快建立现代综合交通枢纽体系成为当前新型城市可持续发展的重要举措。首先,从空港、海港、陆港等方面剖析了广州市综合交通枢纽体系的发展现状并指出存在的问题。然后,阐述了国内外综合交通枢纽规划建设的发展趋势。最后,在分析广州市面临全球一体化进程加速、国家中心城市全面建设、珠三角区域竞争与合作加强等机遇与挑战的基础上,提出了广州市打造国际性综合交通枢纽和中国南方交通枢纽中心的功能定位,以及构建"一核三极"的现代综合交通枢纽体系格局。     

有黏结预应力梁中预应力筋的几何非线性分析

以常规的非线性平面梁元平衡方程为基础,将预应力束视为两端通过刚臂与混凝土梁元节点连接的平面杆元,在局部坐标系(随转坐标系)中计入预应力,根据刚臂在受力后只有刚体运动而本身不变形的特点,采用微分方法导出其在结构坐标系中的切线刚度矩阵,从而获得混凝土梁元与预应力束杆元在结构坐标系中的组合单元切线刚度矩阵;编制了程序,对预应力钢筋混凝土悬臂梁进行几何非线性分析;与ANSYS计算结果比较表明,提出的方法在非线性程度很高时仍能获得高精度数值解,具有对单元数量不敏感,预应力作为非保守荷载的特点容易被计入的优点。     

基于TOGAF的铁路企业架构框架研究

文章分析企业顶层架构设计对企业信息化建设的重要意义,基于TOGAF提出一套适用于铁路的企业架构框架.     

武汉轻轨列车运行控制系统

介绍了应用在武汉轻轨列车的控制系统,着重描述了车载控制器的结构、工作状态、驾驶模式,以及列车定位和测速计算。