公路突发交通事件应急资源配置效率研究*

为合理有效配置公路突发事件下的应急资源,从资源投入与产出角度建立3级评价指标体系,在此基础上将应急资源投入与产出比作为目标函数,引入数据包络分析法构建应急资源配置效率模型,采用TOPSIS法对应急资源配置方案效率进行排序。以新疆10个公路局应急资源配置效率为例,分析其资源投入与产出的冗余度,并对有效决策单元进行排序。结果表明:该模型能获得应急资源配置冗余度,并对其进行资源配置效率分析,从而为公路局进行有效资源配置提供参考。     

空管安全风险管理信息系统分析与设计

针对空中交通服务管理系统(简称为"空管",下同)中存在的安全管理不规范、安全信息不畅通和信息化程度低等安全管理问题,根据空管安全风险管理信息系统(SRMIS)的工作原理,提出SRMIS的业务流程和组织结构,设计了SRMIS的总体结构、风险管控和指标预警等主要功能,研究实现过程中的指标评价、部门评价和模糊综合评价等信息评价方法以及指标预警、因素预警和综合预警等预警预控方法和关键技术。该系统能进行持续的风险识别和综合预警,定期自检、自查、自审,不断改进安全管理工作,并在武汉空管中心实证有较好的应用效果,为空管中心的安全风险管理提供了信息化管理的工具和途径。     

基于分类交通冲突与微观仿真分析的城市交叉口安全诊断及改善

鉴于传统的城市交叉口交通冲突整体评价方法不能深入地分析和解决交叉口内部的交通安全问题,依据流量和相位时长关系确定分类交通冲突评价系数,计算出不同相位阶段中不同交通冲突类型(机-机、机-非、机-人)的交通冲突率和分类综合交通冲突率,从而比较和诊断交叉口内部危险性高的交通冲突类型及所在相位,并应用VISSIM仿真软件评估相应交通安全改善措施对路口交通效率的影响。以北京市光彩北路路口为对象进行实验分析,其结果表明,分类交通冲突技术与微观交通仿真分析的充分结合,可提高城市交叉口安全诊断的准确性及相应改善措施的有效性。     

我国公路交通事故的现状及特征分析

根据2000—2006年全国公路交通事故统计数据,以2006年为重点,分析当前我国公路交通事故的发展形势、地区差异和事故特征。研究表明:我国的公路交通事故自2003年开始总体由快速上升转为持续下降,但高速公路和西部地区的公路交通事故仍有增长可能;与经济欠发达地区相比,经济发达地区的事故总量较大,但事故死亡率较低;国道、省道和高等级公路的事故死亡率均大幅高于其他公路;约80%的死亡事故是发生在平直、一般弯和一般坡等良好路段上的车辆互碰、碰撞行人和翻车,76%的特大事故属于坠车和正面碰撞;雾、雪等恶劣天气更易在高等级公路上引发交通事故。     

空中交通管制员职业素质模糊综合评价

提出一种管制员综合素质的评价方法;构建管制员综合素质评价指标体系和模糊综合评价模型;应用专家打分法确定指标的权重判断矩阵数据和隶属度数据;采用层次分析法对判断矩阵进行处理得到指标权重数据;按照评价模型的程序对权重数据和隶属度数据进行处理,最终得到管制员综合素质的评价值,根据评价结果提出了提高管制员综合素质的对策。     

Experimental and Numerical Verification of Similarity Concept for Dispersion of Car Exhaust Gases in Urban Street Canyons

In urban conditions, car exhaust gases are often emitted inside poorly ventilated street canyons. One may suppose however that moving cars can themselves produce a certain ventilation effect in addition to natural air motions. Such ventilation mechanism is not sufficiently studied so far. A similarity criterion relating the vehicle- and wind-induced components of turbulent motion in an urban street canyon was proposed in 1982 by E. J. Plate for wind tunnel modelling purposes. The present study aims at further evaluation of the criterion and its applicability for a variety of wind and traffic conditions. This is accomplished by joint analyses of data from numerical simulations and wind tunnel measurements.     

A Simple Model for Urban Background Pollution

A simple urban background pollution model is presented. Contributions from the individual area sources, subdivided into a grid net of a resolution of 2km × 2km, are integrated along the wind direction path assuming linear dispersion with the distance to the receptor point. Horizontal dispersion is accounted for by averaging the calculated concentrations over a certain, wind speed dependent wind direction sector, centred on the average wind direction. Formation of the nitrogen dioxide due to oxidation of nitrogen monoxide by ozone is calculated using a simple chemical model based on assumption of a photochemical equilibrium on the time scale of the pollution transport across the city area. The rate of entrainment of fresh rural ozone is governed by this time scale. The model is suitable for calculations of urban background when the dominating source is the road traffic. For this source the emissions take place at ground level, and a good approximation is to treat the emissions as area sources, but with an initial vertical dispersion determined by the height of the buildings.     

匀速行驶小型载客汽车噪声频谱研究

系统测量了5辆小型载客汽车分别以20~100 km/h匀速行驶时的车外噪声频谱,得到了低、中、高各频段声压级随车速的变化关系,进一步与城市道路交通噪声频谱相比较,为从声源上控制城市道路交通噪声提供有力的参考依据。     

OSPM - A Parameterised Street Pollution Model

For many practical applications, as e.g. in support of air pollution management, numerical models based on solution of the basic flow and dispersion equations are still too complex. Alternative are models that are basically parameterised semi-empirical models making use of a priori assumptions about the flow and dispersion conditions. However, these models must, be thoroughly tested and their performance and limitations carefully documented. The Danish Operational Street Pollution Model (OSPM) belongs to this category of parameterised models. In the OSPM, concentrations of exhaust gases are calculated using a combination of a plume model for the direct contribution and a box model for the recirculating part of the pollutants in the street. Parameterisation of flow and dispersion conditions in street canyons was deduced from extensive analysis of experimental data and model tests. Results of these tests were used to further improve the model performance, especially with regard to different street configurations and a variety of meteorological conditions.     

浅析美国和澳大利亚及新加坡道路交通噪声管理与监测

简要介绍了美国、澳大利亚及新加坡在道路交通噪声控制管理与监测技术方面的现状,分析了其经验和特点,结合我国道路交通噪声监测与评价现状提出了相应的建议。