重型车测试工况研究的一种新方法

为了评估车辆尾气排放和燃油经济性。研究重型车测试工况是一项重要的课题。本论文提出了一种新方法用于从速度—时间曲线的行驶数据中提取典型的测试工况。本文介绍了提取这种测试工况的方法,还使用这样的试验工况做了测试尾气排放和燃油消耗的试验,并得出了较好的试验结果。     

中国城市乘用车实际行驶工况的研究

分析了中国3个典型城市(北京、上海和广州)车辆行驶的速度、怠速、最大速度、加速度以及行程等特征及其分布特征;结合交通特性研究了车辆行驶运动学水平。研究表明,现行采用ECE15工况与实际行驶工况相比,车辆燃油消耗被低估约10%;覆盖的车辆工况范围远远小于实际行驶工况,不适用于车辆设计开发要求。     

基于共享排序实现CUBE操作的一个优化算法

CUBE操作在数据仓库/联机分析处理中是一个关键性的操作,它需要计算一个属性列表上的所有可能的组合,并等价于标准sQL中一组group by子句.作者分析了CUBE操作的几种实现方法,并扩展了一种以group by子司共享排序为基础实现CUBE操作的优化算法,在应用中有较好的效果.     

基于GSM的列车临时调度命令无线传输试验系统

阐述一种基于GSM的列车临时调度命令无线传输试验系统的体系结构和工作原理,介绍了调度命令接收终端的硬件和软件设计方案,并对试验系统的运行测试数据进行了分析.该系统已经在原上海铁路分局DF11G机车上安装测试.     

The determinants of car ownership in England and Wales from anonymous 2001 census data

Within the transportation research literature, the attempt to understand and predict the level of car ownership is probably one of the most popular areas of study. The primary reason for this is understandable, having access to a vehicle increases an individual’s (or their household’s) travel options, leading to greater mobility. Secondary reasons for this scrutiny include the need to predict future transport investment in road infrastructure and the commercial demand for new vehicles. This paper attempts to predict the level of household car ownership as a function of the characteristics of the household and the individuals that make up the household. The primary data source for this study comes from the 2001 United Kingdom Census and the analysis methods used are from the discipline of data mining. The results of this study are in line with those from previous research but show a potential to predict the higher levels of household car ownership with greater accuracy than other similar studies.     

连续刚构桥健康监测数据的采集和处理

文章根据连续刚构桥的构造和受力特点,介绍了某连续刚构桥健康监测系统的数据采集方式和定时采集制度,同时对应力、挠度和加速度数据的后期处理方法进行了探讨,为其他同类桥梁的健康监测提供依据。     

Impact of vehicle usage on consumer choice of hybrid electric vehicles

We analyze the vehicle usage and consumer profile attributes extracted from both National Household Travel Survey and Vehicle Quality Survey data to understand the impact of vehicle usage upon consumers’ choices of hybrid electric vehicles in the US. In addition, the key characteristics of hybrid vehicle drivers are identified to determine the market segmentations of hybrid electric vehicles and the critical attributes to include in the choice model. After a compatibility test of two datasets, a pooled choice model combining both data sources illustrates the significant influences of vehicle usage upon consumers’ choices of hybrid electric vehicles. Even though the data-bases have in the past been used independently to study travel behavior and vehicle quality ratings, here we use them together.     

Floating car based travel times for city logistics

City logistics routing requires time-dependent travel times for each network link. We rely on the concept of Floating Car Data (FCD) to develop and provide such travel times. Different levels of aggregation in the determination of time-dependent travel times from a database of historical FCD are presented and evaluated with regard to routing quality. Furthermore, a Data Mining approach is introduced, allowing for a substantial reduction of the volume of input data required for city logistics routing. The different approaches are investigated and evaluated by a huge amount of FCD collected for the urban area of Stuttgart, Germany. The results show that the Data Mining approach enables efficient provision of time-dependent travel times without a significant loss of routing quality for city logistics applications.     

GPS船舶试航(报告)数据后处理系统

采用GPS技术进行船舶试航是一项为船东、船厂普遍欢迎的技术 ,在研制和完善GPS船舶试航实时数据采集系统的基础上 ,本文探讨一种实用的船舶试航 (报告 )数据后处理系统 ,以期提供信息量较大、且方便对船舶性能和试航过程进行深入分析的试航报告。     

基于层叠条件随机场的网络入侵识别

为了能够在网络环境中从大量底层入侵警报信息中正确有效地识别其背后隐藏的攻击意图和规划,提出了基于层叠条件随机场模型的网络入侵识别方法.该方法首先在低层条件随机场中解决对简单的入侵识别,并将结果传递到高层的条件随机场模型以进行对复杂的入侵识别,实现了自适应、智能化的入侵检测系统.实验结果表明,该方法有较低的误报率,综合看来比传统方法优越.