公交最佳出行线路的一个模型及算法

在分析影响最佳出行线路选择评价指标的基础上,建立的最佳出行线路选择模型,可很好地解决最佳出行线路的选择问题．对此类问题的研究具有一定的指导意义。     

Efficient solution algorithm for finding spatially dependent reliable shortest path in road networks

Travel times are generally stochastic and spatially correlated in congested road networks. However, very few existing route guidance systems (RGS) can provide reliable guidance services to aid travellers planning their trips with taking account explicitly travel time reliability constraint. This study aims to develop such a RGS with particular consideration of travellers' concern on travel time reliability in congested road networks with uncertainty. In this study, the spatially dependent reliable shortest path problem (SD‐RSPP) is formulated as a multi‐criteria shortest path‐finding problem in road networks with correlated link travel times. Three effective dominance conditions are established for links with different levels of travel time correlations. An efficient algorithm is proposed to solve SD‐RSPP by adaptively using three established dominance conditions. The complexities of road networks in reality are also explicitly considered. To demonstrate the applicability of proposed algorithm, a comprehensive case study is carried out in Hong Kong. The results of case study show that the proposed solution algorithm is robust to take account of travellers' multiple routing criteria. Computational results demonstrate that the proposed solution algorithm can determine the reliable shortest path on real‐time basis for large‐scale road networks. Copyright © 2016 John Wiley & Sons, Ltd.     

基于轨道交通网络特点的K最短路算法研究

城市轨道交通网络发展带来出行路径选择的复杂性,为了科学掌握线路客流,组织运输,合理引导乘客路径选择,需要开展轨道多路径算法研究;同时,随着生活节奏加快,要求算法高效,注重路径获取的实时性。针对轨道网络特征,将站点之间K最短路搜索转化为线路换乘组合搜索,降低搜索空间复杂度,并利用杭州轨道交通网络进行案例验证。算法明显提升轨道网络K最短路搜索效率,能够更快速响应轨道交通实际运行变化,有助于提升今后轨道交通出行服务应用。     

静态多路径交通分配模型综述

静态交通分配反映路网交通流的拥挤性、路径选择的随机性等典型交通流特征,是交通规划方案评价和路网分析的重要方法.文章在介绍交通分配理论的基础上,对静态多路径交通分配的发展进行分析,并总结了静态多路径非平衡交通分配法的关键问题,分别对路阻函数及路权的计算、有效路径的定义、路网最短路算法、分配算法流程设计4个方面进行研究,总结静态交通非平衡分配法存在的不足,可为交通分配研究提供参考.     

Estimating the most likely space–time paths,dwell times and path uncertainties from vehicle trajectory data: A time geographic method

Global Positioning System and other location-based services record vehicles’ spatial locations at discrete time stamps. Considering these recorded locations in space with given specific time stamps, this paper proposes a novel time-dependent graph model to estimate their likely space–time paths and their uncertainties within a transportation network. The proposed model adopts theories in time geography and produces the feasible network–time paths, the expected link travel times and dwell times at possible intermediate stops. A dynamic programming algorithm implements the model for both offline and real-time applications. To estimate the uncertainty, this paper also develops a method based on the potential path area for all feasible network–time paths. This paper uses a set of real-world trajectory data to illustrate the proposed model, prove the accuracy of estimated results and demonstrate the computational efficiency of the estimation algorithm.     

车流去向查询实现算法

提出一种基于基点基线法计算最短径路里程的车流去向查询算法:全面分析货运列车的行走规律,利用图论中基点基线的概念,将全国货运路网图按照点、线相关的编码规则划分,以适应Dijkstra算法基本思想,并在此基础上提出等代价Dijkstra算法搜索最短里程径路计算的数学模型.将查找车流径路问题转化为寻求发站、车流径路和到站之间的最短径路问题,实现车流去向查询.     

采用COM组件计算铁路货物运价里程的设计方案

介绍用COM组件计算铁路货物运价里程的设计方案,分析货物运价里程对象的数据结构,最短路径算法及其在运价里程计算中的具体实现,COM组件的主要技术参数和运行条件.     

Distributed computing approaches for large‐scale probit‐based stochastic user equilibrium problems

Applications of probit‐based stochastic user equilibrium (SUE) principle on large‐scale networks have been largely limited because of the overwhelming computational burden in solving its stochastic network loading problem. A two‐stage Monte Carlo simulation method is recognized to have satisfactory accuracy level when solving this stochastic network loading. This paper thus works on the acceleration of the Monte Carlo simulation method via using distributed computing system. Three distributed computing approaches are then adopted on the workload partition of the Monte Carlo simulation method. Wherein, the first approach allocates each processor in the distributed computing system to solve each trial of the simulation in parallel and in turns, and the second approach assigns all the processors to solve the shortest‐path problems in one trial of the Monte Carlo simulation concurrently. The third approach is a combination of the first two, wherein both different trials of the Monte Carlo simulation as well as the shortest path problems in one trial are solved simultaneously. Performances of the three approaches are comprehensively tested by the Sioux‐Falls network and then a randomly generated network example. It shows that computational time for the probit‐based SUE problem can be largely reduced by any of these three approaches, and the first approach is found out to be superior to the other two. The first approach is then selected to calculate the probit‐based SUE problem on a large‐scale network example. Copyright © 2011 John Wiley & Sons, Ltd.     

湖北省高速公路计重收费拆分方案

基于高速公路联网收费的原则，提出了联网收费通行费拆分算法，并在湖北省联网计重收费拆分结算系统的基础上，设计了计重货车通行费的拆分算法。     

基手Dijstra算法群布型立交匝道优化

针对多目标最短路径的问题采用线性加权Dijstra算法。在立体交通规划布局阶段，考虑其相互作用关系，提出群布型立体交叉的概念及用最短路径法优化匝道设计的实用方法。以重庆绕城高速公路与射线之间的界石、一品、南彭立交为例，检验该方法的实用性。