基于浮动车数据的交通出行特征库构建研究

浮动车数据是一种常用的实时和动态监测城市交通运行状态信息的数据资源,具有实时性强、数据量大、时间空间相关等特性。以浮动车数据为源数据,通过统计分析、模式识别、关联分析等知识发现技术,计算了城市道路路段平均行程时间、路段通行频率、道路等级3个重要交通出行特征因素;构建了车辆出行特征分析模型库,对车辆的路径选择行为进行模拟,从而为交通管理部门提供实时、可靠的决策依据。     

基于模糊理论的智能最优路径算法

在经典Dijkstra算法原理的基础上,提出基于模糊理论的智能最优路径算法.该算法综合考虑静态交通信息、动态交通信息和人的主观因素等路径选择的影响因素,建立路径选取度模型,确定影响因素的隶属度函数.该方法能够根据用户出行的不同目的和需求,自动调整各影响因素之间的权重,从而使路径选择既能满足用户的主观要求,又能真实反映复...     

一种基于遗传算法的多模式多标准路径规划方法

单一路径评价标准难以满足日益多样化的出行路径规划需求。多标准路径规划成为公众出行服务的研究热点。然而,多标准路径规划本质上是具有NP特性的多标准决策问题,且涉及多种交通出行模式。多个不同标准的权重设置将直接影响路径规划结果。因此,如何科学合理地设置不同标准的权重成为多标准路径规划中的技术瓶颈。本文提出了一种适应多模式交通网络环境的多标准路径规划方法,借鉴遗传算法在求解多标准优化问题中的优势,将其扩展到多模式多标准路径规划中。该方法避免了不同出行标准权重设置中的主观性和不确定性,能够实现更为灵活的交通出行模式自动化组合,为出行者提供满足个性化需求的、多标准的出行路径规划服务。     

出租车经验知识建模与路径规划算法

以出租车采集的浮动车数据,研究出租车司机道路选择的经验和规律,建立出租车司机道路寻径的经验知识模型,将城市交通道路网按该知识模型分成不同等级的经验路网;在此基础上提出基于经验知识的交通道路寻径算法,并以武汉市交通路网和浮动车为实验数据,将本文提出的道路寻径算法与传统的最短路径规划算法进行比较,实验结果表明在起止点相同的情况下,本文选择的路径较好地保持了道路等级的一致性和连贯性,明显减少通行时间,更符合自主出行的认知.     

Dijkstra算法在GIS中的优化与应用

为了提高出行效率,节省出行时间,避开交通情况复杂路段,基于层次分析法与Dijkstra算法,对多种道路交通影响因素进行对比分析并量化赋值,求解出更加准确、合理并能够动态改变的路径规划方法,该方法利用多元数据分析得出最佳路径,优化以道路长度等单一因素解算的最短路径算法,在实际生活场景中有较强的实用性.实验结果表明,通过优...     

基于出租车GPS数据的城市居民出行时空分布研究

随着城市的快速发展,道路拥堵、打车难等问题越来越突出,严重影响了居民的出行效率和生活质量。出租车GPS数据,在一定程度上包含了部分居民出行行为的丰富信息。考虑到出租车载客事件发生于一维道路网络空间,本文提出对出租车上下客事件所在路段进行分析,得到不同时段居民出行的热门路段和区域,分析居民出行时空分布特征,有助于了解交通现状和居民出行需求,提高城市对居民出行活动的服务水平。     

一种健康出行路径动态搜索算法与系统实现

为方便公众优化出行路径,规避或减少空气污染暴露损害,提出一种基于低空气污染暴露的健康出行路径动态搜索算法（dynamic healthy-route search algorithm,DHRSA）,并设计开发了相应健康出行路线规划系统。该算法通过融合土地利用回归制图、暴露风险权重估算和Dijkstra最短路径搜索算法,基于实时空气污染情景动态规划健康出行路径。以长沙主城区为例进行随机车辆出行方式测试实验,通过比较DHRSA算法规划的健康出行路径与传统最短出行路径、最快出行路径的出行暴露风险,验证了该算法的可靠性与系统的实用价值。     

基于GIS和最小交通阻抗的公交出行最佳路径算法

分析了现有公交出行最佳路径算法,并针对现有算法不完善的地方,根据乘客的出行心理,利用GIS的空间分析功能,提出了一种基于最小交通阻抗的公交出行最佳路径算法.首先根据城市公共交通网络的特点抽象出合理的公交网络模型,建立了此网络的拓扑关系,并用有效的数据结构存储此公交网络图;然后根据乘客的出行特点确定了合理的交通阻抗函数;为了进一步提高搜索效率设定了节点限制搜索区域;最后对算法的仿真实现证明了此算法的可行性和有效性.     

基于GIS和最小交通阻抗的公交出行最佳路径算法

分析了现有公交出行最佳路径算法,并针对现有算法不完善的地方,根据乘客的出行心理,利用G IS的空间分析功能,提出了一种基于最小交通阻抗的公交出行最佳路径算法。首先根据城市公共交通网络的特点抽象出合理的公交网络模型,建立了此网络的拓扑关系,并用有效的数据结构存储此公交网络图;然后根据乘客的出行特点确定了合理的交通阻抗函数;为了进一步提高搜索效率设定了节点限制搜索区域;最后对算法的仿真实现证明了此算法的可行性和有效性。     

城市出行天空可视指数

开阔的天空视野有利于营造舒适的城市出行体验,针对如何评价城市交通出行的天空可视能力这一问题,提出了城市出行天空可视指数(sky view index-urban transportation, SVI-UT)。采用4步走策略:街景全景照片获取;基于街景全景照片的天空视觉量计算;腾讯地图服务路径规划;城市出行天空可视指数各指标计算。以中国云南省昆明市中心城区为实验区,多角度衡量居民的城市出行天空可视能力。实验结果表明,SVI-UT为研究人在交通过程中对天空的视觉感知提供了一个新的理论和框架。从公共的街景和交通数据出发,提出了SVI-UT的定量计算框架,拓展了街景图像的实际应用。该指数可以从新的角度指导城市交通规划和城市建设,居民可通过选取SVI-UT值较高的线路和出行方式来提高出行舒适感。     

A multi-period capacitated school location problem with modular equipment and closest assignment considerations

In rapidly growing urban areas, it is deemed vital to expand (or contract) an existing network of public facilities to meet anticipated changes in the level of demand. We present a multi-period capacitated median model for school network facility location planning that minimizes transportation costs, while functional costs are subject to a budget constraint. The proposed Vintage Flexible Capacitated Location Problem (ViFCLP) has the flexibility to account for a minimum school-age closing requirement, while the maximum capacity of each school can be adjusted by the addition of modular units. Non-closest assignments are controlled by the introduction of a parameter penalizing excess travel. The applicability of the ViFCLP is illustrated on a large US school system (Charlotte-Mecklenburg, North Carolina) where high school demand is expected to grow faster with distance to the city center. Higher school capacities and greater penalty on travel impedance parameter reduce the number of non-closest assignments. The proposed model is beneficial to policy makers seeking to improve the provision and efficiency of public services over a multi-period planning horizon.     

Exploring the link between urban form and work related transportation using combined satellite image and census information: Case of the Great lakes region

Aspects of urban transportation have significant implications for resource consumption and environmental quality. The level of travel activity, the viability of various modes of transportation and hence the level of transportation-related emissions are influenced by the structure of cities, i.e., their urban forms. While it is widely recognized that satellite remote sensing can provide spatial information on urban land cover and land use, its effective use for understanding impacts of urban form on issues such as transportation requires that this information be integrated with relevant demographic information. A comprehensive bi-national urban database, the Great Lakes Urban Survey (GLUS), comprising all cities with populations in excess of 200,000 has been created from Landsat imagery and national census and transportation survey information from Canada and the United States. A suite of analysis tools are proposed to utilize information sets such as GLUS to investigate the link between urban form and work-related travel. A new indicator, the Employment Deficit Measure (EDM), is proposed to quantify the balance between employment and worker availability at different transit horizons and hence to assess the viability of alternate modes of transportation. It is argued that the high degree of residential and commercial/industrial land uses greatly impact travel to work mode options as well as commute distance. A spatial interaction model is developed and found to accurately predict travel distance aggregated at the census tract level. We argue that this model could also be used to explore the relative levels of travel activity associated with different urban forms.     

Accessibility tradeoffs in public transit planning

 Spatial accessibility is a critical consideration in the provision of services, both public and private. In public transit planning, accessibility is comprised of access and geographic coverage. Interestingly, these two considerations are somewhat at odds with each other. Access is important because it is the process associated with getting to and departing from the service. Such access is typically perceived of in spatial terms as the physical proximity to transit stops or stations. Additional stops along a route usually mean greater access, because a stop is more likely to be within an acceptable walking/driving standard for a larger number of people. On the other hand, more stops and greater access slow transit travel speeds, thereby decreasing the area of service reachable given a travel time budget. More stops along a route translate to greater service interruption and longer travel times. The faster the travel time, the more desirable the service. Further, if travel times become excessive, then user demand for service will decrease. All of this means that stop spacing along a route is central to accessibility, as it is a tradeoff of access (more stops) and geographic coverage (service efficiency through less stops). This paper details modeling approaches for addressing accessibility concerns in an integrated fashion. Bus-based transit service in Columbus, Ohio will be utilized to illustrate the usefulness of these approaches in transit planning. Received: September 2002 / Accepted: January 2003 This research was supported in part by an Ohio State University seed grant.     

出租车数据的时间序列谱聚类分析

城市空间运行的出租车产生大量的OD数据,数据的时序呈现周期性特点,客观反映人们的出行行为模式,本文采用谱聚类算法对北京五环区域内各空间单元的出行特征及其相似性进行探究。由于空间单元的时空行为特征受空间邻域和功能区划的影响,研究添加邻域因子和功能区因子以改进时间序列的相似性度量方法,从而实现时间序列谱聚类算法的空间和功能区拓展,进而增加人们对不同时空条件下出行行为特征的了解,以便对不同空间单元提供差异性服务,如不同时段公交的发车频次、动态调整商场营业时间、不同时空环境出租车候车点的实时变换、调控和优化不同区域服务保障等,将有助于降低城市能耗,更加合理地利用资源,也有助于居民实现智慧生活。     

基于居民出行活动特征的个体经济水平推断方法

提出了一种基于居民出行活动特征的个体经济水平推断方法。从出行轨迹的移动性指标、基于居住地的出行特征和出行活动链模式3个方面提取13维出行活动特征,以广州市居民出行日志调查数据为训练和测试数据,利用随机森林方法进行个体经济收入水平的推断与检验。结果表明,该方法能够获得最高80%的个体收入水平推断精度。基于家的出行特征（如工作时间（9:00-18:00）离家距离众数等、出行链模式）以及与出行范围有关的移动性指标（如最大距离、回旋半径）在推断个体经济水平上的重要性较高,而衡量出行地点空间异质性的指标（如空间多样性等）重要性相对较低。     

GIS在城市智能公交系统中的应用

随着经济的逐步发展,城市中的交通问题愈发凸显。相比人们出行需求日益增加,交通管理系统的便捷程度和服务水平却相对较低。本文从GIS在城市智能公交系统的应用前景,GIS在城市智能公交系统的应用、以及分析对比GIS在城市智能公交系统在国内应用的几个实例方面强调了城市智能公交系统建立的必然性和可行性,基于GIS的城市智能交通系统的建立将使公交服务更加方便、快捷和舒适。同时,GIS的城市智能交通系统的建立也将帮助政府交通部门为交通管理提供依据。     

基于栅格GIS的公交站点覆盖率算法研究

本文利用栅格分析技术对公交站点覆盖率的计算进行了改进,从高分辨率遥感影像与公交站点信息数据叠加得到的栅格数据中提取三个栅格矩阵:记录公交站点ID号及其位置信息的栅格矩阵、道路网络上各点的出行阻抗矩阵、不在道路网络上各点的出行阻抗矩阵,对这三个阻抗矩阵进行栅格运算,计算公交站点的覆盖率,并通过南京城区部分公交站点的分布说明本文算法的具体应用情况。     

Obstacle‐limited service coverage: A new geospatial approach

Service coverage is a crucial component of spatial decision‐making involving facility siting. Determining coverage requires knowledge about travel behavior and accessibility across a region, as well as supporting methods of measurement and derivation when actual travel cannot necessarily be observed. When service is provided using vehicles that move freely without the restriction posed by roads (e.g., airplanes, helicopters, unmanned aerial vehicles/drones, boats, ships, and submarines), straight‐line travel is regularly assumed. However, this common assumption is often violated by geographical obstructions, resulting in overestimated service coverage. To date, no methods have been developed capable of accounting for obstacle‐limited service coverage. Existing methods either completely ignore obstructions or crudely estimate impacts on travel. In this research, we develop a novel method, ESP‐Cover, capable of deriving accurate obstacle‐limited coverage without introducing representation errors. A location siting problem involving drone‐based package delivery is presented to highlight the necessity of explicitly accounting for obstacles in system design. The assessment results demonstrate the importance of accurate derivation of the obstacle‐limited coverage for spatial decision‐making and the accuracy of the ESP‐Cover method in coverage derivation.     

基于Android和JavaEE旅游助手系统的实现

本系统通过Esri公司发布的ArcGIS for Android结合天地图发布的各种OGC(Open Geospatial Consortium)服务构建了Android客户端,服务端以Linux为操作系统,Apache Tomcat为Web服务器,Postgre SQL/PostGIS为数据库,使用Java EE技术进行开发,构建了旅游助手系统。该系统不仅在Android设备上实现了地图浏览、兴趣点查询等常规功能,还实现了旅游路线分享、进入景区地理围栏时接收景区多媒体信息推送、扫描景点二维码获取景点介绍等特色功能。通过旅游助手,游客便于分享自己的旅游路线和心得,获取其他游客分享的路线和心得;景区景点便于向游客推送相关的宣传信息和景点介绍,促进景区景点信息化的建设。