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91.
In urban areas where transit demand is widely spread, passengers may be served by an intermodal transit system, consisting of a rail transit line (or a bus rapid transit route) and a number of feeder routes connecting at different transfer stations. In such a system, passengers may need one or more transfers to complete their journey. Therefore, scheduling vehicles operating in the system with special attention to reduce transfer time can contribute significantly to service quality improvements. Schedule synchronization may significantly reduce transfer delays at transfer stations where various routes interconnect. Since vehicle arrivals are stochastic, slack time allowances in vehicle schedules may be desirable to reduce the probability of missed connections. An objective total cost function, including supplier and user costs, is formulated for optimizing the coordination of a general intermodal transit network. A four-stage procedure is developed for determining the optimal coordination status among routes at every transfer station. Considering stochastic feeder vehicle arrivals at transfer stations, the slack times of coordinated routes are optimized, by balancing the savings from transfer delays and additional cost from slack delays and operating costs. The model thus developed is used to optimize the coordination of an intermodal transit network, while the impact of a range of factors on coordination (e.g., demand, standard deviation of vehicle arrival times, etc) is examined. 相似文献
92.
This paper explores the tenuous link between speeding behavior and accident causation, one that has not been well established in the international literature to date. Taking advantage of established engineering conventions and formulae, we were able to set up an a priori hypothesis suitable for testing. Utilizing this formal scientific method (which GIS researchers have been criticised for not using) we establish a statistical link for this relationship. Our methodology can be used to support all police intervention strategies, including the controversial photo radar systems. The results from our research have been entered into a GIS in order to create a map for spatial display. This map illustrates the relative probability or risk of collision occurrence resulting from speeding at all intersections and interchanges within the scope of the study. It is suggested that this methodology could easily be maintained with periodic updates of data, thus creating a dynamic model from which to monitor traffic safety within the city. Furthermore, this model can be utilized to study specific strategies, allowing for the scrutiny of before, during and after effects. The study area is the entire city of Calgary, Alberta, Canada, and includes all traffic collisions occurring during the year of 1994. 相似文献
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随着汽车技术的快速发展,汽车的舒适性、安全性、智能化程度不断提升,导致车载功能电器不断增多,为提高车载各功能电器的可靠性,连接各功能电器的汽车线束多采用集成式设计,将发动机线束、机舱线束、仪表线束、车身线束及其它功能线束集合设计成一条线束;直接导致集成式线束的导线数量、单根导线长度大幅增加,线束的可制造性大幅降低,装配过程控制也愈加困难。为解决集成式线束生产制造及过程控制的难点和问题,我公司在现有HMES系统的基础上,设计和开发了适合集成式大型汽车线束流水线装配管理模块。本文将以HMES装配模块的开发设计和应用方案,与各位共同探讨和交流。 相似文献
96.
Fred Wegman 《国际交通安全学会研究报告》2017,40(2):66-71
Estimates by the World Health Organization suggest that, on a yearly basis, road crashes kill 1.25 million people—nearly 3400 road fatalities per day—and injure up to 50 million. Traffic injuries are not equally spread over the world, however; some countries are hit harder than others, and the chance of being killed in a road crash depends on where one lives. Almost 90% of all traffic casualties occur in low- and middle-income countries (LMIC). Globally, the number of fatalities per 100,000 population (mortality rate) ranges from less than 3 to almost 40. The rate is less than 9 in high-income countries (HIC) but averages around 20 in LMIC, with the African region demonstrating the highest rate (26.6). While road safety trends have been positive in HIC over the last few decades, trends in LMIC are not telling a positive story: road fatalities are expected to increase to almost 2 million road fatalities per year by 2020.The United Nations has adopted several resolutions on road safety and proposes actions to tackle the global road safety crisis. Considering the current level of road safety to be unacceptable, the UN has taken several initiatives. One effort, the Decade of Action for Road Safety 2011–2020, has generated substantial activity around the world over the last couple of years. Furthermore, it is very encouraging that the UN included road safety in the Sustainable Development Goals that it laid out in September 2015. Road safety is part of the public health agenda and the urban development agenda. Measured in “real actions,” however, the responses so far from the overall global community and individual countries do not suggest that we are already on the right track to bringing down the death toll on roads.The future of road safety is uncertain and definitely not the same for all regions of the world. Countries with a mature road safety approach and an ambition to make further progress are expected to move in the direction of a pro-active approach: a Safe System approach. It is reported that many LMIC, meanwhile, are on the brink of designing road safety strategies and implementing action plans. The international community is willing to support LMIC, but LMIC cannot simply copy successful HIC strategies because local circumstances differ. The principles of successful HIC strategies are applicable, but the priorities and action plans should take root in and align with local conditions. 相似文献
97.
一种用汽油燃烧系统模拟发动机台架催化剂热老化的方法 总被引:1,自引:0,他引:1
采用通用汽车公司的快速老化程序RAT-A,分别在FOCAS燃烧系统及发动机上对催化剂在老化前和老化后的性能进行对比试验。结果表明,FOCAS燃烧系统能够对催化剂进行和发动机类似的老化。与发动机台架试验相比,FOCAS系统有明显的优点,如严格地控制空燃比使其变化幅度很小、空燃比稳定运行的范围宽、活动部件少及易操作等。 相似文献
98.
针对汽车同步器的特点及设计过程,应用基于特征的参数化CAD技术与优化设计以及有限元分析理论相结合的方法,讨论计算机辅助设计系统的体系结构和开发方法。基于Pro/E平台,应用Visual C 语言二次开发了汽车同步器计算机辅助设计系统。根据具体设计要求生成的设计实例证明,本系统能显著缩短产品设计周期,提高设计效率,是汽车同步器设计的较好工具。 相似文献
99.
高精度车辆动态导航技术现状和展望 总被引:1,自引:0,他引:1
车辆定位与导航系统是ITS中的重要组成部分。汽车导航系统主要是信息技术、数据通信技术和自动控制技术等通用电子技术向汽车电子领域的移植。如何在现有的基本硬件配置下进一步提高车辆定位精度,实现精确实时的导航服务是需要迫切解决的问题。从实现车辆动态导航的各关键环节出发,介绍了提高精度和实时性的最新有效方法,为更好地实现车辆定位与导航系统在ITS中的作用提供了新的思路。 相似文献
100.
杨学辉 《武汉船舶职业技术学院学报》2008,7(4):8-11
本文参照国际海事组织关于船舶定线制的设计规范和标准,依据《中华人民共和国内河交通安全管理条例》、《中华人民共和国内河避碰规则》等法律、法规,对三峡水库通航支流船舶定线制的设计原则和基本方法,进行了探索和研究。 相似文献