城市主要道路平面交叉口安全管理研究

基于目前城市干道平面交叉口交通流量密集的状况,分析并讨论影响平面交叉口安全管理的影响因素,可为提高城市道路交叉口的交通安全管理水平提供依据及方法。     

Applying multiple kernel learning and support vector machine for solving the multicriteria and nonlinearity problems of traffic flow prediction

This article proposes to develop a prediction model for traffic flow using kernel learning methods such as support vector machine (SVM) and multiple kernel learning (MKL). Traffic flow prediction is a dynamic problem owing to its complex nature of multicriteria and nonlinearity. Influential factors of traffic flow were firstly investigated; five‐point scale and entropy methods were employed to transfer the qualitative factors into quantitative ones and rank these factors, respectively. Then, SVM and MKL‐based prediction models were developed, with the influential factors and the traffic flow as the input and output variables. The prediction capability of MKL was compared with SVM through a case study. It is proved that both the SVM and MKL perform well in prediction with regard to the accuracy rate and efficiency, and MKL is more preferable with a higher accuracy rate when under proper parameters setting. Therefore, MKL can enhance the decision‐making of traffic flow prediction. Copyright © 2012 John Wiley & Sons, Ltd.     

保宜高速公路建设信息化管理平台的构建与应用

阐述了高速公路建设信息化管理的概念和意义,介绍了湖北保宜高速公路信息化管理平台的总体架构与功能特点,具体介绍了征迁管理、资金管理、质量管理等三个子系统的结构组成、功能特点以及应用效果。     

螺旋钢桩抗拔特性的现场试验研究

根据螺旋钢桩现场抗拔试验中61根试验桩的监测数据绘制Q—S曲线,推算各类桩型的平均极限承载力,分析桩长、叶片数量、叶片间距、首层叶片埋深、叶片直径等参数对螺旋钢桩极限抗拔承载力的影响,试验结果表明螺旋钢桩的极限抗拔承载力随桩长和叶片直径而增加,叶片间距和首层叶片的埋深均存在临界点。分别通过慢速加载法和快速拉拔法测试螺旋钢桩桩极限抗拔承载力,快速拉拔法测得的极限承载力平均值约为慢速加载法极限承载力的2．0倍。     

Conflict Resolution through Negotiation in a Railway Open Access Market: a Multi-agent System Approach

Abstract

Open access reforms to railway regulations allow multiple train operators to provide rail services on a common infrastructure. As railway operations are now independently managed by different stakeholders, conflicts in operations may arise, and there have been attempts to derive an effective access charge regime so that these conflicts may be resolved. One approach is by direct negotiation between the infrastructure manager and the train service providers. Despite the substantial literature on the topic, few consider the benefits of employing computer simulation as an evaluation tool for railway operational activities such as access pricing. This article proposes a multi-agent system (MAS) framework for the railway open market and demonstrates its feasibility by modelling the negotiation between an infrastructure provider and a train service operator. Empirical results show that the model is capable of resolving operational conflicts according to market demand.     

基于ZigBee的无线交通同步控制系统的设计与实现

通过研究ZigBee协议和无线传感器网络同步控制算法,提出了基于ZigBee技术的交通控制系统方案,设计了基于ATmega128L单片机、CC2420射频收发器等芯片的硬件节点,实现了无线交通系统通过对路面交通信息的采集,传输到交通指挥中心,再通过关卡节点发送数据包来对交通信号灯进行无线控制。研究及实验结果表明该设计在实际生活中具有很好的实用价值。     

基于路网仿真的地铁运营协调性分析

面向地铁运营状态的动态性、不确定性及多因素动态关联性,采用路网运营仿真技术,基于路网客流分布状态变化,从网络整体角度研究地铁运营协调性的定量分析方法.将运营协调决策问题分成资源配置、服务设计、客流控制三个层次,提出利用运能需求匹配度,将系统不同层次的协调性进行关联分析的思想.从运输单元运能需求匹配度的均衡性和换乘服务效能两个方面构建网络运营协调性分析指标,给出基于分布熵的协调性指数计算方法.构建地铁路网运营中观仿真模型,给出面向协调性研究的路网仿真实验流程.最后,以北京地铁为例,进行案例研究,利用路网客流分布仿真实验数据分析两条线路的运营协调性,给出优化后的列车开行间隔.     

巴黎市郊铁路与地区快线的起源

大巴黎地区的交通组织以成功著称于世,成功的重要原因在于公共交通供给充分,这其中城市轨道交通发挥了至关重要的作用,特别是地区快线和市郊铁路的协同,对于解决单中心特大城市或网络化城市都有极强的借鉴意义。介绍早期的法国铁路(市郊铁路)基础条件,以及快线的构思与形成的发展途径,过程曲折辗转,观念、意识、利益在冲突中逐渐磨合走向协同,自然天成。在我国城市化大潮涌动的新形势下和对市域快速轨道交通的饥渴中,期望对国内市域快速轨道交通的健康发展、避免多走弯路起到一定的参考作用。     

Al2O3-Al-MgO混合纳米粒子润滑脂添加剂的摩擦学性能

在MRH-3高速环块摩擦磨损实验机上,研究了混合纳米微粒Al,Al2O3,MgO加入到通用锂基脂中的综合摩擦学性能.采用扫描电子显微镜,能量色散谱仪分析了摩擦表面的形貌和元素组成.结果表明:含有混合纳米Al,Al2O3,MgO粒子的润滑脂添加剂比单种纳米粒子显著提高通用锂基脂的减摩、自修复和抗极压综合性摩擦学能.     

六盘水市白鹤高架桥荷载试验及分析

以通车五年多交通流量大的贵州六盘水白鹤高架桥为工程背景,通过对该桥进行桥梁有限元模型仿真分析和现场静动载试验,对桥梁现阶段实际受力性能、承载能力和行车性能做出了评价,对大跨度桥梁的维修和养护具有重要参考作用.