基于最短路程的城市公交咨询系统的数学模型

<正>城市规模越来越大,公交系统随之越来越复杂.大中型城市有几百条公交线路,这些复杂公共交通网络在给市民带来很多方便的同时,也给城市居民特别是外地游客的乘车路线的选择带来困惑.如何乘车成为市民的一件麻     

网络图时间参数的性质及应用

关于网络图时间参数之间的关系,一些运筹学教材多未论及,因而对网络图的应用问题缺乏较好的计算方法,有的甚至导致错误.除了通常的时间参数外,我们给出任一事项对应的准关键路线的定义,它是指从该事项到网络图终点的各条路中工序时间之和的最大者.于是事项的最迟时刻就是工程完工期减去该事项对应的准关键路线上的工序时间之和.可以证明时间参数的以下性质:(记号如[1])     

区间数型多目标联运路线优化问题的模型与算法

联运路线优化问题直接关系到货物运输的费用、时间和运输质量.首先分析了联运路线优化问题的数学模型及虚拟运输网络图;其次,将区间数排序的思想及属性值为区间数的多属性决策方法引入适应度函数的设计中,提出了一种求解区间数型联合运输路线优化问题的混合型遗传算法,给出了染色体编码、遗传算子设计、适应度函数定义及群体多样性控制的方法;最后用示例对算法的有效性进行了验证.     

基于变长度染色体混沌遗传算法的专用交通道优化

大型运动会要求主办方在规定时间内将相关人员从运动员村运送至指定比赛场馆.基于大城市日趋严重的交通拥堵,为满足运送时间的要求,通常在城市公共交通网络中设置专用交通道.但专用交通道的设置会对城市公共交通产生影响,最小化其对城市公共交通影响是专用交通道优化问题的关键.针对此类问题,在给出了改进的混合整数规划模型的基础上,提出了基于问题特性的变长度染色体混沌遗传算法,包括变长度染色体编码、混沌个体初始化、交叉操作、变异操作、适应度函数的计算和不可行解的惩罚、修复策略等.最后,以经典算例和随机生成算例对算法有效性进行了验证.     

在企业经营管理中应用数理统计方法尝到甜头

一、引言太原市公共交通公司是一个拥有六千名职工,近五百辆公共汽、电车,一百余辆各式卧车的大型企业,地处平均海拔八百米的黄土高原。担负着市、郊区一百九十二万人口的公共交通任务.全年营运里程二千三百万公里,年耗油量五百万公升,价值二百八十万元,占总成本的百分之十五点三.是山西省耗油大户之一.去年初,公司实行成本目标管理以来,围绕运营服务、增收节能、技术改造、文明建设等目标,应用数理统计方法,分析了耗油因素,制定了节油方案;研究了各场、路队的技术经济管理水平,采取了有效的管理措施,取得了明显的经济效果. 二、用R型因子…     

现代城市公共交通系统运营社会效益的模糊综合评价

城市公共交通属于社会公共产品,其建设与运营不仅要考虑经济效益,还需要考虑社会效益.从公共服务水平、乘客满意度和可持续发展三个大方面考虑,构建了公共交通运营社会效益的评价指标体系.通过层次分析法确定了各指标的权重,从而建立了基于层次分析法的模糊综合评价模型.然后运用该指标体系和模型对上海市公共交通情况进行算例分析,结果表明,该评价方法科学合理、可操作性强,并指出上海公共交通运营社会效益处于中等水平,提高"安全水平"和"平均出行时间"等指标水平将显著的提高其社会效益.     

基于层次分析法可拓学的小城市公交服务评价

从基础设施服务和企业运营服务两方面,构建适合于小城市公共交通服务评价的指标体系,运用层次分析法确定指标的权重系数.根据可拓学理论构造经典域、节域和关联函数,建立小城市公共交通服务的层次分析法-可拓学的综合评价模型,并以江苏省泰州市公交为例,验证模型的实用性.     

网络图修改方法的两个创新

随着社会的不断向前发展，网络图的应用越来越广泛。比如项目管理中的网络图、电网中的控制图和交通运输中的控制图等都是常见的网络图。网络图越复杂，修改起来越麻烦，本提出的网络图修改方法的两个创新能大大提高网络图修改方法的效率。网络图修改的第一个创新是网络图节点的高效删除．第二个创新是平行工序变为顺序工序的自动实现。     

网络计划编制系统中网络图的自动生成

本文从设计角度，系统地介绍了一个计算机网络计划编制系统中如何实现计算机辅助生成网络图和时间坐标网络图的方法与步骤。并阐述了资源优化的计算机实现。     

城市综合实力的协调评价

利用协调聚类分析方法对我国十九个超大城市进行了综合评价和排序,其结果与主成分方法所得的结果基本一致,再一次证明了该方法的实用性和可操作性.     

基于网络治理的公交服务总效益和各主体决策分析

为解决我国公交服务效率与公平难以兼容问题,本文引入网络治理理论假定政府、企业和社会群体三方合作的基础上,从最大化公交服务效益构建公交服务网络治理模型,剖析政府、企业和社会群体努力水平、控制权配置和产出效率对公交服务总效益的影响,并对模型分析结果进行数据模拟。结果表明:公交服务总效益与三方主体的努力水平、控制权和产出效率紧密相关,只有在合理范围内参与方的努力水平、控制权的提高有利于公交服务效益增加,当超出合理范围时会导致总效益的降低;而三方主体产出效率越高,公交服务总效益越大;控制权配置与自身的产出系数、努力水平相关,产出系数、努力水平越高,则其对应的控制权比例就越大。     

基于DEA-BCC模型的南通公交系统绩效评估

公交线路的量化绩效评估对提高公交运营效率、改善运营服务水平具有重要意义.以南通45条常规运营线路作为各决策单元,采用因子分析和主成分分析法,消除投入产出指标中的信息重叠因素后,应用DEA方法建立面向产出(BCC)的数学规划模型,计算比较决策单元之间的相对效率,对南通市公交系统作出客观绩效评价.     

A time–space network based exact optimization model for multi-depot bus scheduling

The vehicle scheduling problem, arising in public transport bus companies, addresses the task of assigning buses to cover a given set of timetabled trips with consideration of practical requirements, such as multiple depots and vehicle types as well as depot capacities. An optimal schedule is characterized by minimal fleet size and minimal operational costs including costs for unloaded trips and waiting time. This paper discusses the multi-depot, multi-vehicle-type bus scheduling problem (MDVSP), involving multiple depots for vehicles and different vehicle types for timetabled trips. We use time–space-based instead of connection-based networks for MDVSP modeling. This leads to a crucial size reduction of the corresponding mathematical models compared to well-known connection-based network flow or set partitioning models. The proposed modeling approach enables us to solve real-world problem instances with thousands of scheduled trips by direct application of standard optimization software. To our knowledge, the largest problems that we solved to optimality could not be solved by any existing exact approach. The presented research results have been developed in co-operation with the provider of transportation planning software PTV AG. A software component to support planners in public transport was designed and implemented in context of this co-operation as well.     

基于APC和GPS数据的青奥会期间南京公共交通的调度与优化

为了得到青奥会期间南京市合理有效的公交调度方案,本文针对青奥会场馆、运动员村、旅游点等附近的南京公共交通线路,建立模型与算法.首先,通过APC数据与GPS数据的匹配,对客流数据进行站点匹配预处理,根据已有客流量数据,训练小波神经网络,从而对客流分布情况进行预测,然后基于客流预测结果,采用有序聚类法,实现客流高低峰时段的合理划分.其次,详细分析调度问题的关键所在,以时段总发车次数和乘客等待时间两个因素作为目标函数,将时段最大、最小发车间隔和满载率等作为约束条件,提出基于APC和GPS的公交车辆辅助调度模型,通过遗传算法对模型进行求解,得出不同时段的发车间隔和配车次数,并对模型的性能进行评估.以南京市D7路公交运营线路的实际客流数据为例,采用MATLAB软件进行仿真实验,得出优化结果.结果表明所建模型是合理的,从而为调度时刻表的生成提供了科学的依据.     

Adjustment boarding and alighting passengers on a bus transit line using qualitative information

Obtaining data to use in an urban public transport operation planning and analysis is problematic, particularly in urban bus transit lines. In an urban environment and for bus services, most ticketing methods can be used to record passengers getting on board but not getting off, and current methods are unable to make a proper adjustment of boardings and alightings based on the available data unless they do alighting counts. This paper presents a method whereby counts are made at fewer stops and qualitative information on alightings and/or vehicle loads between consecutive stops is used to make the boarding and alighting adjustment as a previous step to obtain the real origin and destination (O/D) of passengers allowing the O/D matrix calibration by using the loads between stops. Qualitative information can be obtained by the vehicle’s driver or an on board observer, avoiding the necessity of counting many stops in planning period. The method is applied to a real bus transit line in Malaga (Spain) and to a set of 50 different bus transit lines with number of stops ranging from 10 to 75. The results show that the proposed method reduces the adjustment errors with regard to traditional methods, such as Least Square Method, even in the situation where no qualitative information is used. When qualitative data is used on alightings and loadings, the reduction of the average error is over 50%.     

Transformation of urban public transport financing and its effect on operators’ efficiency: evidence from the Czech Republic

The purpose of this study is to analyze changes in the efficiency of urban public transport in the Czech Republic. Network data envelopment analysis and cluster analysis were applied to data from 19 urban public transport systems during 2004–2016. The series structure of the network was considered, including production and consumption stages with three external inputs (employees, rolling stock, and energy), one final output (passengers), and two intermediate products (vehicle-kilometres and seat-kilometres). The relationship between changes in efficiency and the method of financing for the operation of transport services was explored through standard statistical methods. One of the main findings was that the efficiency of smaller transport systems with complicated access to sources of funding were systematically less efficient, particularly in the consumption stage. These trends were even more significant after the reorganization of urban public transport funding in 2010.     

公交服务治理模式的效益比较研究

公交服务的市场化改革需要选择合理的治理模式以应对产生的种种问题,各模式间的效益比较就成为选择的关键因素。在理论比较PPP模式和网络治理模式的基础上,本文以PPP模式为参照对象,假定公交服务参与主体平等的合作,从各主体的控制权分配、努力水平和产出效率构建公交服务总效益模型,并进行了模型的理论分析和数据模拟,结果表明:总效益与各方主体的努力水平、控制权和产出效率紧密相关,仅当政府和社会群体间的边际成本替代率在合理范围内时,网络治理模式的总效益大于PPP模式,当超出合理范围时会使前者小于后者。     

基于线路“异质性”假设的轴辐式公共交通网络优化研究

特大城市公共交通局部静态拥堵问题日益成为制约公共交通网络运行效率提高的关键。针对这一问题改变线路“同质性”假设,在线路“异质性”假设的基础上,提出了将轴辐式网络设计运用到公共交通领域中来,综合考虑居民采用公共交通方式出行的单位运输可变成本、不变成本、枢纽换乘成本等要素,将枢纽间大型客车干线运输所带来的规模经济效应进行量化,构建了基于单分配、多枢纽、混合式网络结构特征的轴辐式公共交通网络优化模型,旨在多重约束下通过枢纽布局降低网络运输成本,提高公共交通网络站点的可达性。最后根据模拟退火算法对模型进行求解,并通过算例分析与讨论的方式验证了模型的有效性。     

Estimating bus passenger waiting times from incomplete bus arrivals data

This paper considers the problem of estimating bus passenger waiting times at bus stops using incomplete bus arrivals data. This is of importance to bus operators and regulators as passenger waiting time is a key performance measure. Average waiting times are usually estimated from bus headways, that is, time gaps between buses. It is both time-consuming and expensive to measure bus arrival times manually so methods using automatic vehicle location systems are attractive; however, these systems do not usually provide 100% data coverage and missing data are problematical. The paper contributes to the general theory of estimating headway variance using incomplete data. Various methods for replacing missing buses or discarding spurious bus headways are compared and tested on different data sets.     

基于游客年龄特征的旅游巴士定价研究

为旅游巴士设计合理的定价,对旅游公共交通的发展有着积极影响。通过对游客出行偏好的分析,考虑不同年龄阶段的游客在选择行为上有较大的差异,建立了上层以旅游巴士企业利润最大为目标,下层为多方式多人群弹性需求随机用户平衡的旅游巴士定价模型,并设计了改进粒子群算法求解问题。数值实验结果表明:1)年龄特征会影响最优定价策略,考虑游客年龄在选择行为上的差异得出的票价更优;2)舒适度敏感系数对定价有影响,且旅游巴士较常规公交,舒适度更好,一定程度上提高了旅游巴士企业的竞争力;3)改进粒子群算法较标准粒子群算法,有更好的求解性能和质量。