浅谈城市地铁建设期间交通的需求

随着经济的高速发展,大城市人口密度的增加,私家车数量的剧增,城市交通压力也越来越大。为缓解城市交通紧张的现状,地铁建设迫在眉睫。然而在地铁建设期间,施工占道却让本就拥堵的交通压力有增无减。本人就城市地铁建设期间的交通需求问题进行浅析。     

现实主义视角下的“铁幕演说”文献解析

1946年3月5日,英国前首相丘吉尔在访问美国期间发表了题为《和平砥柱》的演讲,史称"铁幕演说"。"铁幕演说"在二战后历史中具有重要的文献价值,被认为是正式拉开了冷战的序幕,而其中的主要思想在一定程度上契合了现实主义国际关系理论的观点。     

1xEV-DO系统数据流量研究

本文首先分析了 1xEV -DO前向业务信道的链路特性和今后将面临的新业务特性 ,然后着重对 1xEV -DO的无线资源分配和平均业务流量作了研究。     

关于汉语/英语AMR语音编码参数统计特性的研究

自适应多速率（AMR）算法是第三代移动通信系统中语音业务所采用的语音编码标准。为研究AMR算法应用于汉语语音和英语语音所产生的差异，本文针对ARM语音编码算法的特点，在处理分析了大量汉语语音数据的基础上，对算法中的线谱频率（LSF）、基音周期等关键编码参数进行了比较并给出相应结合。本文的研究有助于AMR算法针对汉语语音的性能优化。     

基于排队论的公交站点停车位优化及实证分析

优化设计公交站点停车位数是站点建设的一步重要工作，停车位数过多或过少都会影响公交系统的运营效率和服务质量。鉴于此，此文将探讨基于排队理论的公交站点停车位数优化方法，并以武汉市街道口站为例，运用该方法进行了实证分析，以期对武汉市的公共交通建设提供理论上的参考。     

专家对19世纪上半期德国交通政策的影响分析

19世纪上半期,德国的一批专家对政府的交通政策产生了较大的影响。他们给当时奋发向上的市民提供了社会舆论支持,同时他们自己又在更高的舞台上表演。他们在“是否采纳铁路作为交通工具”、“大技术体系”等方面进行了充分的讨论,给政府提供了富有建设性的意见,并由此创造了学者政治的模式。专家们并不谋求直接在政治上发展,而是把自己看成超党派的公众的良心;而政府听取他们的意见,则体现了政府尊重科学的明智之举。     

利用互信息进行网络异常检测的熵特征优选

首先讨论了传统流量统计分析的缺点,指出熵分析能够反映更多潜在的信息,发现传 统流量统计分析不能发现的网络异常。其次,讨论了流量熵和计数熵的不同,指出两者应该 配合使用,不能如现有研究中一样片面地使用其中一种。最后,用互信息法分析了两种熵的 常用特征,实验发现两者分别呈现冗余状态,在剔除冗余之后检测的效率有明显提高,且不 失检测准确率。     

北京城区交通便捷性空间分异特征及问题分析

城市交通条件是反映城市宜居性的重要标志之一,解决城市交通拥堵问题是建设"宜居北京"的重中之重。在界定研究区域,建立城市交通便捷性指标的基础上,通过对北京市部分区域进行问卷调查,基于北京市交通满意度综合评价模型,对北京市交通出行结构、出行满意度等空间分异特征进行分析。利用ArcGIS空间分析工具,将主观交通便捷性评价和客观交通相关数据进行对比分析,用以分析研究区范围内交通便捷性。结果表明,北京市交通发展中存在的问题有:城市建设与城市交通基础设施发展不协调;道路网络规划不尽合理;"职住分离"导致交通问题的加剧;公共客运交通难以应对私人交通工具的强劲挑战;城市交通管理系统缺乏有效整合。     

Preventing motor vehicle crash injuries and deaths: science vs. folklore lessons from history

Abstract

Not long after the beginnings of motorization in the early 1900s, deaths and injuries from motor vehicle crashes became a problem in a number of high-income-countries (HIC)s, especially the United States. With the biggest problem the US led early efforts to address this issue, and for six decades these efforts were based on folklore (ie a body of widely held but false or unsubstantiated beliefs). They were not evaluated, but clearly were unsuccessful as crash deaths and injuries continued to rise. It was not until the 1970s that a broader range of countermeasures began to be adopted and was scientifically evaluated, and as a result, crash deaths and injuries declined. This history has important lessons today for many low-and-middle-income countries that have growing numbers of motor vehicle crash deaths and injuries, many of which are pedestrians and motorcyclists. This is because there continue to be advocates for many of the failed approaches (especially educational) that dominated the early efforts in HICs.     

Estimating emissions based on the integration of microscopic traffic simulation and vehicle dynamics model

This study proposes an integrated simulation approach, which consists of a microscopic traffic simulation model, a vehicle dynamics model, and an emission estimation model, in order to estimate emissions based on more reliable vehicle performance measures. The vehicle performance measures such as engine power and engine speed significantly relate to the amount of emissions, and road curvatures and inclinations are the core inputs affecting these vehicle performance measures. Therefore, providing reliable vehicle performance measures reflecting the road geometric attributes is critical for a reliable emission estimation. This study proposes to use the microscopic traffic simulation model for generating vehicle trajectories, which is advantageous in modeling various traffic situations, and the vehicle dynamics model for producing the vehicle performance measures based on the vehicle trajectories. Finally, the outputs from the vehicle dynamics model are fed into the emission estimation model to compute emission measures. This study conducted a case-study using two road sections, one is a hypothesized road section, including various curvatures and inclinations with regular variations, and the other is a Kesselberg road section, which is an actual geometry in Bayern, Germany. The emission measures are estimated in these case-study road sections using both an existing simulation approach and the proposed integrated simulation approach. The difference between these two emission estimation approaches is discussed in terms of the emission measures, including fuel consumption, nitrogen oxides, and particulate matters.