基于遗传算法的城市轨道交通接运公交线网规划

分析了城市轨道交通接运公交线网的功能，初步界定了车站影响区，并将其离散化编码表示，定义参数，以运营者消耗和使用者消耗之和最小为公交线网优化目标函数，建立模型，最后介绍了使用遗传算法搜索最优路线的计算步骤。     

略谈支线航空

简略地讨论了发展支线航空的两个关键因素，地区人均经济水平的提高和交通运输系统的综合优化，支线航空的发展，是必然的，但是一个渐过的过程，取决于上述两个因素所决定的市场需求，同时，还对飞机的可靠性和寿命对运营成本的影响，做了简略的分析。     

多换乘点响应型接驳公交运行线路的协调优化

为尽量降低响应型接驳公交系统的运行费用，提出多换乘点间运行线路协调设计的构想。针对同时包含预约需求和实时需求的混合需求，构建多换乘点响应型接驳公交系统运行线路的2阶段协调优化方法，并设计优化流程。第1阶段仅考虑预约需求，首先将预约乘客按有/无特定换乘点要求进行分类，在此基础上构建预约需求下多换乘点多车辆运行线路的协调优化模型。在协调优化模型中，优化目标是由乘客时间费用、车辆运行费用、以及惩罚费用所构成的系统总成本最小；乘客时间费用包括乘客候车时间的惩罚费用、车内乘客在需求点的等待时间费用以及乘客车上时间的惩罚费用3个部分；车辆运行费用包括车辆启动费用、路段行驶费用、需求点的停靠费用、车辆早到引起的等待费用4个部分；考虑的约束条件包括乘客候车和车上的软时间窗、乘客换乘点要求、车辆容量、车辆出行时长等。第2阶段根据规则判断是否响应实时需求，并根据响应情况重新优化后续各班次的运行线路。针对第1阶段模型，基于模拟退火算法设计求解算法。研究表明：在预约需求或混合需求条件下，与各换乘点运行线路独自优化相比，协调优化方法均能显著降低运送全部响应乘客所需的平均运行距离和平均总成本；仅有预约需求时分别降低5.4%、19.8%，新增实时需求后分别减少1.4%、21.7%；与固定发车间隔相比，分时段调整发车间隔，也能有效降低运送全部响应乘客所需的平均运行距离和平均总成本，仅有预约需求时分别降低18.2%、17.2%，新增实时需求后分别减少19.97%、25.06%，说明多换乘点间车辆路径的协调运行是提升响应型接驳公交运行效率的有效途径。     

Economic conditions for minibus usage in a multimodal feeder network

The introduction of minibuses into the transit fleets of some cities makes it more important than ever to investigate the economic and operating conditions of these vehicles for various transit and paratransit services. A high performance transit system is of great interest, owing to its desirable characteristics. However, it is not feasible to establish and use such a system all over a city. It is therefore necessary to support a high performance transit system with other modes to extend its area of operation (owing to higher demand) and also to connect those areas that are not covered by the high performance system to it. This paper considers the use of minibuses in the design of metro line feeders and to characterize the economic domain in which it is efficient to use them in a feeder network. Based on results from ant colony optimization, the performance measures of minibuses are compared with those of conventional buses to help make decision makers aware of the use and role of these vehicles. The study contradicts the common belief that, since minibuses require similar driver costs to those of conventional buses, it is not economical to use them in a transit fleet; in fact, it is shown that minibuses can displace conventional buses in some situations in a feeder network.     

提高城市轨道交通换乘效率分析

在分析城市轨道交通换乘模式的基础上,研究轨道交通在规划、建设和运营三个方面的不足及其对换乘的影响。借鉴国外轨道交通先进经验,提出提高我国城市轨道交通换乘效率的建议,为今后城市轨道交通换乘效率的提高做为参考依据。     

高速铁路正馈线故障抢修问题探讨

结合既有京广线AT供电区段电气化铁路运营经验,分析徐兰高速铁路郑州—西安段AT供电制式的工作原理,对正馈线的故障抢修问题进行探讨,并给出了一种简单、快捷的故障抢修方案。     

支线集装箱运输船的多规格集装箱的混装设计研究

支线集装箱船是国际航运业的主要组成部分,目前主流支线集装箱运输船多采用货舱内安装固定式导轨架,装载20ft、40ft标准集装箱;如货舱内装载货其他规格非标集装箱,需要采用移动式导轨架,但也会导致集装箱装载效率低的问题。为了满足多种规格集装箱混装的要求,本文以某1000TEU支线集装箱运输船为例,设计了一型应用于货舱内的的固定式导轨架,以及应用于主甲板的一体化箱柱,大大提高了装载种类和装卸效率。本文的研究成果成功应用到了实船运营中,为支线集装箱运输船货舱多规格集装箱混装提供了借鉴和参考。     

Port system evolution – the emergence of second-tier hubs

Some evidence has emerged of second-tier hubs inserting themselves between hubs and feeder ports, producing a new hierarchy of port networks. This article aims to establish the dynamics of this process based on illustrative cases in Asia, South America, and Europe. Findings reveal spatial factors to include a cluster of small ports with minimal sailing distance within a given range, suitable channel and berth depth, and ideally high capacity inland links. From the economic perspective, demand-side factors include a local captive market and aggregated demand to be captured from other ports, while supply-side factors include diseconomies of scale at traditional hubs, an increase in direct services, an increase in large feeder vessels calling from first-tier hubs which are then transhipped to smaller feeders for serving local ports, and an increase in overland servicing of local smaller ports. From a strategic perspective, vertical and horizontal integration in the shipping sector has produced extensive network economies, whereby shipping lines look to create group-specific port hierarchies, enhanced in the presence of aggressive management strategies and supportive policies. This finding suggests that proactive port stakeholders can in certain circumstances seize the opportunity to capture this role within their port range.     

牵引变电所馈线电流的概率模型

基于随机过程理论,采用数值分析方法,通过对大量实测数据的统计分析,用β-函数拟合牵引变电所馈线电流的概率密度.采用蒙特卡罗法,获得了牵引变电所馈线电流的子样,为牵引变电所馈线电流的过程分析提供了大量信息.牵引变电所馈线电流的仿真结果与实测数据的比较表明,二者的统计规律基本相同,说明所采用的方法是有效的.     

直流馈线DDL保护参数的设定

介绍直流牵引供电系统中直流馈线DDL保护的动作原理,以及保护参数的设定原则,并举例说明.