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101.
The safety of signalized intersections has often been evaluated at an aggregate level relating collisions to annual traffic volume and the geometric characteristics of the intersection. However, for many safety issues, it is essential to understand how changes in traffic parameters and signal control affect safety at the signal cycle level. This paper develops conflict-based safety performance functions (SPFs) for signalized intersections at the signal cycle level. Traffic video-data was recorded for six signalized intersections located in two cities in Canada. A video analysis procedure is proposed to collect rear-end conflicts and various traffic variables at each signal cycle from the recorded videos. The traffic variables include: traffic volume, maximum queue length, shock wave characteristics (e.g. shock wave speed and shock wave area), and the platoon ratio. The SPFs are developed using the generalized linear models (GLM) approach. The results show that all models have good fit and almost all the explanatory variables are statistically significant leading to better prediction of conflict occurrence beyond what can be expected from the traffic volume only. Furthermore, space-time conflict heat maps are developed to investigate the distribution of the traffic conflicts. The heat maps illustrate graphically the association between rear-end conflicts and various traffic parameters. The developed models can give insight about how changes in the signal cycle design affect the safety of signalized intersections. The overall goal is to use the developed models for the real-time optimization of signalized intersection safety by changing the signal design. 相似文献
102.
Different models using belief functions are proposed and compared in this article to share and manage imperfect information about events on the road in vehicular networks. In an environment without infrastructure, the goal is to provide to driver the synthesis of the situation on the road from all acquired information. Different strategies are considered: discount or reinforce towards the absence of the event to take into account messages agings, keep the original messages or only the fusion results in vehicles databases, consider the world update, manage the spatiality of traffic jams by taking into account neighborhood. Methods are tested and compared using a Matlab™ simulator. Two strategies are introduced to tackle fog blankets spatiality; they are compared through an example. 相似文献
103.
15吨沙漠专用汽车设计 总被引:1,自引:0,他引:1
为适应我国国民经济发展的需要,加速西部地区油气资源的勘探和开发,须向石油工业提供能适应在我国沙漠地区中行驶的运载车辆。本文就重型沙漠汽车的设计、结构选型、布置及主要参数的确定进行了论述。 相似文献
104.
从客运专线对GSM—R系统所提出的业务需求和服务质量指标的角度出发,就如何提供高质量和高可靠性的无线网络,在覆盖设计方案上进行了探讨,可供GSM—R系统工程设计参考。 相似文献
105.
106.
随着不断增长的船舶交通量和危险货物的运输,对海洋环境潜在威胁的加大和大众对海洋环境保护意识的不断增强,指定和实施特别敏感海域已成为越来越多国家防止海洋污染的政策之一。然而,作为一种需要实施特殊环境保护的海域,特别敏感海域的指定目前在IMO引起了非常激烈的讨论。本文主要介绍了PSSA的发展历程及其热点问题,并阐述了对我国建立PSSA的一些想法。 相似文献
107.
关于“三种广义凸性”一文的注记 总被引:1,自引:0,他引:1
指出了文[1]中的定理5.1的证明过程是错误的,并给出了一个引理,定理的正确的证明和一个推论. 相似文献
108.
The influence of workplace environment on lung function of shopkeepers working near National Highway in Jalgaon: A note 总被引:1,自引:0,他引:1
S.T. Ingle N.D. Wagh B.G. Pachpande V.S. Patel S.B. Attarde 《Transportation Research Part D: Transport and Environment》2005,10(6):476-482
The inferior ambient air quality was observed near highway passing through Jalgaon urban center. Among the pollutants critical level of particulates are observed at the roadside during May 2003 to April 2004. The shopkeepers working at the highway sides are at high risk of exposure to the air pollution caused by heavy highway traffic. The lung function test of the shopkeepers shows significant decrease in forced vital capacity, forced expiratory volume in one second and peak expiratory flow rate. The regular periodic health checkup and use of nose mask will protect the health of shopkeepers working near National Highway passing through Jalgaon urban center. 相似文献
109.
预不变拟凸函数的新性质及应用 总被引:1,自引:0,他引:1
对一类新的广义凸函数-预不变拟凸函数作了进一步研究。借助于η-不变凸集和函数的上图(E(f)={(x,α)∶x∈K,α∈R,f(x)≤α})得到了预不变拟凸函数的几个新的性质,然后还给出了预不变拟凸函数在数学规划问题中的两个重要应用,从而完善了对此类广义凸函数的研究。 相似文献
110.