公交动态信息系统之数据库应用——比较数据介接效能

近年来,公交动态信息系统的应用越来越广泛与普及。公交动态信息系统多使用关系型数据库,而随着Web2.0时代的来临、基础建设的不断完善,数据库面临大量数据的传送、频繁的写入操作。公交动态信息系统中,传统的关系型数据库已远不能满足现代需求。文中探讨了非关系型数据库之特性,对2种数据库之数据介接做测试,对比二者之效能,以作为后续将非关系型数据库与关系型数据库整合应用于公交动态信息系统之依据。结果显示,当数据库内数据量较少时,其运行时间较小,二者间的优势均并不明显,但在千万数量级数据量情况下,MongoDB则比SQLserve具显着优势。因此公交动态信息系统之应用层面上,介接公交数据中心之大量数据时,可使用非关系型数据库,以达节省时间,提高系统效能的目的。     

基于CATIA的公交车骨架建模方法

公交车骨架建模目前尚没有统一的建模方法,建模工具品种繁多,多根据工程师的经验及个人喜好进行建模。CATIA软件具有强大的三维建模能力和智能化的树结构,在车身设计中得到越来越广泛的应用。在CATIA建模过程中,建模方法对于提高建模效率,确保建模的准确性和后期修改的方便性至关重要。本文介绍了基于CATIA的公交车骨架建模方法及快速建模技巧,得到了较高质量的几何模型,模型可修改性较强,建模效率高,为公交车骨架CATIA快速建模提供了方法参考。     

基于操纵稳定性的某客车空气悬架系统结构改进

针对某空气悬架客车在行驶转向时车身侧倾角过大问题,提出在后空气悬架导向臂尾端添加车身侧倾稳定板的改进方案。对改进前、后空气悬架系统进行了KC分析,结果显示改进后的悬架系统侧倾刚度得到了有效提高。基于刚柔耦合建模方法,建立了改进前、后整车多体动力学模型。仿真结果显示改进后车辆稳态回转时车身侧倾角明显减小,不足转向度也有所改善;整车试验结果验证了仿真结果的正确性和改进方案的可行性。     

DD6120HCI大客车热力特性的实验研究

本文对大客车热力特性进行了实验研究，实验内容包括车厢气密性，客车热力特性，空调系统制冷能力以及车围结构导热性等。本文还讨论了汽车稳太热载荷及车围结构导热的计算方法。     

列车通信网络(TCN)配置及传送数据的规范化

为了实现列车的互操作性,必须对列车总线上传送的数据规范化,而列车通信网络配置规范化是传送数据规范化的前提。文章分析了国内6种动车组网络配置的特点,对网络配置和传送数据规范化提出了建议,供今后网络设计者参考。     

Recognising customers' patterns of bus service patronage using a loyalty framework

With the aim of identifying typical characteristics of travellers, traditional segmentation approaches were based on socio-demographic variables. However, the approaches could not reveal the factors motivating individual behaviour. This result led to an emerging interest in psychological research models that are adhered to the decision-making process. Among various related theories, the concept of loyalty was attractive because the major purpose of establishing a loyalty concept is to recognise a customer's pattern towards a given service. However, there were few efforts aimed at determining market segments based on a loyalty framework. In addition, there was no consensus achieved on theoretical loyalty typology due to different empirical findings in different market contexts. This study aims to be the first loyalty-based attempt to provide an operational method of segmenting bus service market. Seeking practical implementation, another focus of this study is to determine typical characteristics of the market segments. Analyses that included cluster techniques were conducted on questionnaire data collected from 333 respondents in Hidaka city, Japan. A cross-classification between relative attitude and service patronage was successfully established, dividing the market into four segments. Segments of loyalty and no-loyalty were observed to be dominant over the remaining market. In contrast, the spurious loyalty segment was small and insignificant. An expansion of the latent loyalty segment was also observed when moving from the intention phase to the actual behaviour phase. Notably, not only demographic factors but also social awareness variables including environmental concern and elderly support were observed to be significant in distinguishing customer segments from one another.     

基于hyperworks的某客车车身结构有限元分析

以某6120大客车为模型,通过建立客车车身的有限元模型,采用hyperworks软件,Radioss求解器求解。对客车在不同极限工况下的受力情况进行分析,为客车车身的后续改进提供指导。     

城市驾驶员分类指标研究

城市驾驶员是交通系统的重要组成部分,了解其分类有利于更好的进行驾驶行为的研究。本文以南京市城市驾驶员为例,通过实际问卷调查,并运用数理统计方法对城市驾驶员的分类进行研究,提出了城市驾驶员的分类指标及各指标的权重比例。在个人属性、驾驶技术和驾驶行为三个一级指标中,个人属性权重比例最大,即其在城市驾驶员的分类中极为重要,对城市驾驶员实际驾驶影响较大。研究结果为城市驾驶员分类别的深入研究提供了理论依据和科学方法。     

An optimization model for bus fleet replacement with budgetary and environmental constraints

ABSTRACT

As maintenance and operation costs increase with usage over time, equipment is replaced when the value of new equipment is more attractive. Some methods have been developed to solve this problem. In the public transport sector, such problems are frequently analyzed by fleet managers and determined by bus age restriction regulations. We propose an Integer Programming model that integrates both budgetary and environmental constraints (CO₂ emissions) which, as far as we know, have not previously been studied in conjunction. The study aims to determine the optimal replacement plan for a fleet of diesel buses of different size, age, maintenance costs and emissions rates, with new (less polluting) diesel buses over a time horizon of 50 years. The results indicate that it is possible to reduce emissions with a low annual budget using an optimal replacement policy.