基于优化SVM的城市快速路网交通流状态判别

以交通流率、速度和占有率为输入参数,采用交叉验证法优化模型惩罚参数C和核函数参数γ,建立以径向基为核函数的支持向量机模型,判断道路断面交通流状态;结合设计的道路网综合状态指数,依据自由流、拥挤流和阻塞流状态下占有率划分区间,构建城市快速路网交通流状态判别方法;最后以某一区域路网为例,进行了实证性研究．结果表明：该方法对道路断面交通流状态判别精度可达92．22％;同时能够实现道路网范围内对自由流、拥挤流和阻塞流状态的判别,判别精度可达86．67％．     

国产CBTC系统安全认证模式探索

轨道交通系统作为大容量公共交通工具,其安全性直接关系到广大乘客的生命安全．为了保证轨道交通系统的运行安全性,系统必须在其投入运行之前进行安全认证,只有取得相应的安全授权才能投入运行．结合北京轨道交通亦庄线示范工程中信号系统的安全认证过程,探讨适合我们国家的地铁建设过程中的安全认证模式,在应用国际安全标准的同时,必须结合我们国家的实际情况开展相关的研究工作,从产品研发和工程实施全生命周期各个阶段进行安全分析和设计,把风险控制到可以接受的水平以下．     

铁路桥梁梁端伸缩装置的结构特点探讨

铁路桥梁梁端伸缩装置是大跨度桥梁的重要部件,为实现轨道的连续性和平顺性,需要具备滑动和支撑功能。对国内各种铁路桥梁梁端伸缩装置的结构特点、工作原理以及各自优缺点进行分析对比,目的在于分析出国内自主研发的梁端伸缩装置需要改进的思路和方向。我国要实现铁路桥梁梁端伸缩装置完全自主化,需要吸收国外先进的技术和经验,同时提升自身的制造精度和水平。     

Decision Support Systems for Public Transport Management: The Athens Public Transport Authority Project

This article reports on an implementation study of a computerised decision support system for public transport management for the Athens Public Transport Authority (APTA). The study analysed the current situation, specified user requirements, determined system functionality, designed the system architecture, organised the project and, finally, planned dissemination activities. The decision support system covers the main public transport management activities of APTA - transport service provision, economic and financial planning, passenger complaints and suggestions, and personnel management - offering its users the possibility to study the potential effects of their decisions before implementation. To achieve this, the system will consist of a data warehousing system, for the integrated management of a wide variety of data sources, and of online analytical processing tools, for information analysis and scenario testing. The system architecture has been designed to offer robustness, flexibility, rich functionality and open connectivity. The system aims to help APTA reduce operational costs and provide a better transport service, attracting more passengers to public transport and reducing, in the process, congestion and pollution.     

新型水下储油技术

针对南海百米左右水深边际油田的开发，提出了一种新型的适用于可移动生产储油平台的水下储油方式。介绍了方案的基本配置、工作流程及维温方式。通过设置不同功能的舱室和布置监测仪器，保留了油水置换低投资的主要优点，避免了环境污染。各种设备位于水面以上，维护方便。基本解决了制约工程应用的技术问题。     

Daily activity pattern recognition by using support vector machines with multiple classes

The focus of this paper is to learn the daily activity engagement patterns of travelers using Support Vector Machines (SVMs), a modeling approach that is widely used in Artificial intelligence and Machine Learning. It is postulated that an individual’s choice of activities depends not only on socio-demographic characteristics but also on previous activities of individual on the same day. In the paper, Markov Chain models are used to study the sequential choice of activities. The dependencies among activity type, activity sequence and socio-demographic data are captured by employing hidden Markov models. In order to learn model parameters, we use sequential multinomial logit models (MNL) and multiclass Support Vector Machines (K-SVM) with two different dependency structures. In the first dependency structure, it is assumed that type of activity at time ‘t’ depends on the last previous activity and socio-demographic data, whereas in the second structure we assume that activity selection at time ‘t’ depends on all of the individual’s previous activity types on the same day and socio-demographic characteristics. The models are applied to data drawn from a set of California households and a comparison of the accuracy of estimation of activity types and their sequence in the agenda, indicates the superiority of K-SVM models over MNL. Additionally, we show that accuracy in estimating activity patterns increases using different sets of explanatory variables or tuning parameters of the kernel function in K-SVM.     

機車騎士未戴安全帽辨識之研究

臺灣地區機車車輛數眾多,但在應用在機車騎士執法上這一層面較少討論到。國人普遍駕駛習慣不良,而道路交通事故的發生常常就是因爲用路人不守法的行爲所致,近年來未戴安全帽而招舉報的案件上昇10萬多件,使得交通安全的問題日益嚴重。文中使用監視攝影機,透過模糊類神經演算法的運算,篩選出未戴安全帽者,並可結合顔色特徵作進一步分析,提高其辨識率,進行未戴安全帽的辨識工作。這一研究經簡單測試有九成的準確率,在智慧型執法系統中有輔助的效應,也殿立了後續發展的基礎。     

动力分散型城郊快速电动车组转向架方案设计

介绍一种动力分散型城郊快速电动车组转向架的主要技术参数和基本结构方案。     

支持向量机在货运量预测中的应用研究

在分析现有货运量预测方法所存在问题的基础上,建立了货运量预测的支持向量机模型,并以我国1981～2001年的货运量和相关经济指标的历史统计数据作为学习样本,分别选用3种不同的核函数,通过拟合训练和外推预测分析,验证了支持向量机用于货运量预测的有效性,并对模型中的有关参数进行了探讨分析。     

基于PID控制的电控空气悬架系统设计

以飞思卡尔公司16位单片机MC9S12DP256为核心控制单元,基于PID控制策略,并利用Matlab、Labview软件。针对气囊-组合电磁阀,对电控空气悬架的软、硬件控制系统进行设计。控制系统可较好地控制车身高度,抑制系统振荡,改善电控空气悬架的性能。