Network Signal Setting Design: Meta-heuristic optimisation methods

This paper aims to investigate the application of meta-heuristic optimisation methods to Network Signal Setting Design. The adopted approaches are (i) three step optimisation, in which first the stage matrix (stage composition and sequence), the green timings at each single junction are optimised, then the node offsets are computed in three successive steps; (ii) two step optimisation, in which the stage matrix is defined at a first step, then the green timings and the node offsets are computed at a second step. In both approaches the stage matrix optimisation is carried out through explicit complete enumeration.In the first approach multi-criteria optimisation is followed for single junction signal setting design (green timings), whilst the coordination (node offsets) is approached through mono-criterion optimisation, as well as for the synchronisation (green timings and offsets) in the second approach.A new traffic flow model mixing CTM and PDM has been applied. This model allows to explicitly represent horizontal queuing phenomena as well as dispersion along a link. Some meta-heuristic algorithms (i.e. Genetic Algorithms, Hill Climbing and Simulated Annealing) are investigated in order to solve the two problems.The proposed strategies are applied to two different layouts (a two junction arterial vs. a four junction network) and their effectiveness is evaluated by comparing the obtained results with those from benchmark approaches implementing mono-criterion optimisation only.     

汽车主观评价综合评分方法研究

本文以各项主观评价项目评分值为依据,运用模糊聚类分析的方法得到反映各"样本车型"与"目标车辆"(各项主观评价分值最优的车辆,下同)的"接近程度"的排序情况,依据此排序结果,构造"样本车型"的综合评价评分值并通过训练得到相应的BP神经网络结构.当输入车辆各项评价项目评分值后,该BP神经网络结构能够按照车辆与"目标车辆"的...     

网络型监控系统的设计与实现

提出一种基于公共电话网络的远程监控系统，以提高大量无人值守通信机房设备维护的效率和及时性。介绍监控系统的组成、工作原理以及监控软件的设计，阐述采用多线程技术实现高速、可靠的数据通信。实际应用表明系统设计合理，工作稳定、可靠。     

城市轨道交通网络规划理论方法研究进展

在详细分析、总结国内外城市轨道交通规划领域的研究成果和存在问题的基础上,总结归纳了网络规划指导思想、规划原则、规划的要点、网络规模、网络优化、轨道项目的建设排序、客流预测理论和方法,指出我国城市轨道交通规划工作已经取得较大的进步和发展,对规划的特征和规律有深层认识,加强了定性定量的分析论证,使城市轨道交通网络规划的合理性日趋提高,但也存在许多有待进一步发展和完善之处。对我国城市轨道交通网络规划理论方法的发展提出了新建议。     

Multi-scale robustness model for highway networks under flood events

Transportation system infrastructure often experiences severe flood-related disruptions such as overtopping, erosion, and scour. The ensuing damages can result in enormous direct and indirect economic losses to the traffic network and consequently the individuals through conditions like inaccessibility to commuters and reduction in traffic safety. Many studies have claimed that a robust transportation system could significantly prevent such consequences from natural hazards such as floods, highlighting the importance of robustness measures that could be used by decision-makers to properly manage flooded transportation system. Most available measures related to network robustness assessment are qualitative, and while some recent studies have focused on such evaluation using quantitative assessment approaches related to environmental or social-economic operations, they lack the holistic view towards robustness under flood events. This study develops a composite multi-scale transportation-system robustness model considering flood hazards by synthesizing geographical damage recognition, topological functionality analysis, network operation evaluation, and traffic-user loss estimation. This integrated model has been applied in a real-world highway network, mainly revealing that a given intensive flood occurrence at different locations may result in a variety of after-flood disruptions in the transportation network. To assist the asset owners with developing more reasonable prevention and recovery plans, the developed multi-scale robustness index presents both visible multi-denominational flood consequences and an overall post-event transportation-system robustness indicator.     

从需求谈青藏线通信组网设计

本文从需求出发,从设计的角度介绍了青藏线通信设计组网方案及其方案的完善。     

GSM-R网络安全性分析与对策

GSM—R是在GSM的基础上,针对铁路移动通信的特点而开发的一种专用无线通信系统,其安全性受到网络结构与用户终端移动性本身的制约。本文通过分析GSM—R网络的体系结构特点,讨论了GSM—R系统中存在的网络安全隐患,并提出了相应的防范措施。     

高速公路收费系统网络故障的快速判断

介绍了如何直观地、快速地判断高速公路收费系统的网络故障。     

PLC在智能型铁路信号电源屏中的网络设计

介绍了S7—200系列PLC在智能型铁路信号电源屏集散监测系统中的网络通信的程序设计，并对PLC的组网及自由口通信作了详细的阐述。     

无线局域网技术概述

论述了近年来发展迅速的无线局域网技术,并通过实际工程案例,介绍了相关的知识。