Transport in an urban context

There are three distinct kinds of problems with which the urban transport planner has to deal. Congestion is the one to which both analytical and policy making effort have been traditionally directed. More recently environmental objectives and a concern for the transport facilities available to disadvantaged groups have been given a higher priority. Unfortunately, neither of these objectives is adequately catered for by standard analytical methods or transport planning instruments and recent analytical and institutional developments embody attempts to rectify this defect. But the task of converting good intentions in these respects into good policies is complex and some of the apparently obvious solutions, such as public transport subsidy, may even be counterproductive. It would be unwise to expect any cheap and easy solutions to the problems to emerge.     

论绿色交通与交通的可持续发展

在城市交通问题与城市环境问题日益严重的情况下,可持续发展的交通尤为重要。众多可持续发展的理念中,“绿色交通”的理念正在方兴未艾的城市建设中实施着。城市交通的可持续发展与社会、经济、生态环境的可持续发展是相互协调和促进的。单单以满足增长的交通需求来确定城市交通建设规模,不符合可持续发展思想。本文作者分析了我国城市,特别是大城市交通上所存在的问题,基于这一问题提出了如何进行“绿色交通”的实施,以达到交通可持续发展的目的。     

深圳市公交票价及财政政策研究

面对越来越严峻的城市交通形势,深圳政府已经认识到必须要加大对公交行业的投入,以建立可以与私人交通方式相竞争的公交体系。其中,公交票价和财政政策是非常重要的研究内容。鉴此就深圳目前面临的票价和财政问题,结合国外发达国家的相关经验,在对整个行业形势和交通政策进行深入研究的基础上,提出适合深圳发展的关于公交票价和财政政策方面的建议,使政府、公交公司、乘客三者之间能取得一个较好的平衡点。     

城市个体机动交通出行的限制对策

随着国民收入水平的日益提高和汽车工业的发展,城市私人机动车拥有水平呈逐年上升趋势,个体机动交通工具的出行成为越来越多家庭的选择。机动车给城市生活带来便利的同时也给城市带来了诸如交通拥堵、环境污染、社会成本增加等问题。为了解决这些问题,借鉴国内外限制机动车出行的成熟经验和政策措施,从税费政策、区域限行措施和停车政策三方面加以分析,提出限制个体机动交通出行的相关对策。     

中央政府对城市公交建设发展的财政扶持政策——法国的相关政策演变综述及对我国的启示

一般认为,城市公交的建设发展是地方事务,相关支出不属于国家财政补贴的范畴,应由地方财政负担。这一认识正在发生变化。当前公交优先发展已经成为一些国家环境战略的重要组成部分,而在地方层面,公交的建设发展也常常突破既有的行政边界,成为跨地域问题,并且和产业发展、环境保护等其他社会经济问题紧密关联。我国政府在确立公交优先发展战略的基础上,也正在考虑设立中央财政专项基金的必要性和可行性,用以扶持引导地方的公交建设和发展。在此背景下,本文选取颇具代表性的欧洲国家法国为案例,考察回顾近40年来其相关政策的发展与演变,从三个发展阶段剖析政策演变的动机、成因及效果,阐述相关的措施和手段,最后总结出法国政策经验可供我国相关改革借鉴学习的方面,以期为当前的政府决策提供参考。     

生态城市理念下的绿色交通规划演进——迈向可持续发展的城市交通系统

本文主要通过对比综述生态城市理论背景下的绿色交通发展,同时总结国内外城市绿色交通研究成果以及实践案例经验,探讨在新的时代如何能更高效地解决城镇化进程中各种环境与交通的问题,进而寻找一种满足城市居民宜居便捷的使用要求的同时有利于控制城市无序蔓延的交通体系。通过研究国内外城市绿色交通规划理论与实践经验,并结合现今社会环境与自然环境影响因素,总结合理的可持续的城市交通系统发展模式。     

Transport Planning in Jakarta

This article is concerned with existing proposals for improving public transport in Jakarta. Although Jakarta has a long history of transport studies, with more than 25 studies undertaken since 1975, public transport has experienced no obvious improvement. This article critically evaluates existing proposals, with the focus on how they attempt to address problems related to bus transport. The analysis reveals that, by adopting the standard Urban Transport Planning (UTP) process developed in the context of Western industrial cities, the transport studies have been largely directed towards inappropriate technology-transfer solutions. The studies uniformly propose replacing the existing bus system with short-term solutions that implement 'bus priority' schemes. The analysis also reveals that, rather than planning coherently, the proposals for Jakarta have been highly fragmented and lacking in detail. This is due largely to the nature of the studies, that regard bus improvement as a temporary measure prior to the implementation of a mass rapid transit (MRT) system, and also because of their over-reliance on market mechanisms, claiming that such mechanisms will allow 'self-correction' of the problems.     

Transport Planning in Jakarta

This article is concerned with existing proposals for improving public transport in Jakarta. Although Jakarta has a long history of transport studies, with more than 25 studies undertaken since 1975, public transport has experienced no obvious improvement. This article critically evaluates existing proposals, with the focus on how they attempt to address problems related to bus transport. The analysis reveals that, by adopting the standard Urban Transport Planning (UTP) process developed in the context of Western industrial cities, the transport studies have been largely directed towards inappropriate technology-transfer solutions. The studies uniformly propose replacing the existing bus system with short-term solutions that implement 'bus priority' schemes. The analysis also reveals that, rather than planning coherently, the proposals for Jakarta have been highly fragmented and lacking in detail. This is due largely to the nature of the studies, that regard bus improvement as a temporary measure prior to the implementation of a mass rapid transit (MRT) system, and also because of their over-reliance on market mechanisms, claiming that such mechanisms will allow 'self-correction' of the problems.     

Numerical Analysis of the Erosion and the Transport of Fine Particles within Soils Leading to the Piping Phenomenon

About 50% of the world's dam failures are triggered by piping, which is a primary cause of embankment breaks. The phenomenon of piping results from the erosion of soil particles and their transport within a soil mass. In this paper, a numerical method is proposed to analyze the erosion within soils and the transport of eroded soil particles by adopting the concept of the erosion rate of soils. In such an analysis, the saturated-unsaturated seepage flow of the pore liquid, the detachment of the soil particles from the soil fabric, and the migration of the eroded particles are taken into consideration, and the equations related to the conservation of the pore liquid and the eroded soil particles are numerically solved. This numerical simulation allows for the procurement of the temporal alteration and the spatial distribution of the porosity, the particle size distribution, and the concentration of the detached soil particles in the pore liquid, as well as the distribution of pore liquid pressure. The results have revealed that the method can reproduce the experimental data from previous studies on the internal erosion of soils and that it qualitatively predicts, from the numerical experiments, the typical development of piping within soils, such as soil blocks and embankments, as the solutions to the initial and the boundary value problems of the governing equations.     

重庆南坪中心交通枢纽改造方案设计理念

重庆南坪中心交通枢纽工程位于城市中心区,影响因素多,过境城市快速路、轻轨为两种主要的交通方式。为较好解决城市交通问题,结合现有道路、周边建筑情况,采用了主线道路下穿直行、地面道路单循环(一大环套两小环)、轨道交通地下直行的交通组织形式。轨道与城市道路的便捷衔接,实现了立体化的枢纽交通功能,且将该交通系统与周边商业、旧城改造等进行了充分的考虑,为城市中心区的发展创造了良好的基础条件。     

管道输送系统在固体物料运输中的应用

采用管道输送固体物料技术，在国外已有大量的应用实例，但是在国内尚处于起步阶段，是一项具有一定应用前景的新技术。本文根据国外管道输送固体物料技术的实际运行经验，并结合贵州瓮福磷矿磷精矿管道输送系统的建设过程，从运输方案比较、管道运输系统设计以及采用管道输送固体物料应注意的问题三个方面，阐述了管道输送在固体物料中的应用。     

公交查询算法优化

随着中国经济的快速发展,城市人口越来越多,由此引发了很多社会问题,许多城市交通拥挤已是不争的事实。发展公共交通是缓解这一问题的一个较好的方法,而公交查询系统是方便市民的一个重要的公共服务。目前国内有不少的公交查询系统,但都存在些问题,其中主要是查询效率低。本文简单介绍了公交查询的普通算法,在此基础上详细介绍了如何对该算法进行改进,并比较了二者所需的时间复杂度,得出后者比前者查询效率大大提高,最后将改进算法运用到公交查询系统中。     

中小城市公共交通规划指标研究

由于中小城市交通基础设施差,对外交通联系差等特点,公交交通发展面对的问题也较多,在城市规划上为城市后续发展提供良好基础,建立有效的评价指标体系,进而为交通规划提供可靠保证具有一定意义。文中对广东清远市中心城区的公共交通进行远期规划和评价,并提出可供借鉴的评价指标。     

面向新世纪的城市交通方式结构选择—南京城市交通发展战略研究实践

本文结合南京城市交通发展战略研究的实践,分析了交通方式结构的主要决定因素和发展规律,并在此基础上简要介绍了南京远景交通方式结构的确定过程。     

环境科学中的渗流力学问题

针对环境科学研究中的渗流力学问题,从环境科学理论和渗流力学理论出发,探讨了挥发性有机污染物在土壤中的迁移机制和规律、地下水多组分反应溶质的迁移模型和规律;分析了垃圾填埋场气体迁移和二次污染问题。在此基础上,提出了挥发性有机物的迁移过程及控制机制的不确定性的两个方面和多组分水化学模型与水动力迁移模型的耦合模型建立的必要性。文中分析对环境科学与渗流力学交叉研究问题的深层次认识具有重要的理论价值和实际意义。     

中国城市绿色交通——改善交通拥挤的根本性策略

文章首先回顾了世界上城市交通发展存在的环境和资源问题,即便是在发达国家,很大一部分小汽车的出行并非是必须的.我国正处于城市空间结构和新交通体系建立的关键时期,只有建立绿色交通体系,才能抑制小汽车的过度使用,有效地提高人们的出行效率.针对我国城市不同于世界其他国家城市的具体发展情况,提出了中国绿色城市交通的模式.论文从与城市交通有关的空间规划策略、降低排放的技术策略和调节使用的政策和经济手段分析在我国建立绿色交通体系的途径和措施.经验告诉我们,一味追求小汽车畅通的城市给一代人某些时段畅快可能需要后辈几代人的偿还.     

Transport and industrial and commercial location

This paper concerns itself with looking at the importance of transport and related infrastructure on the occupancy of new building and premises. Much regional and urban policy focuses on the importance of land use and building availability as an attraction for industrial and commercial growth. Such facilities, however, provide only one form of infrastructure and this study looks at the influence of local transport quality on the exploitation of new premises. It draws upon a large survey of new premises in the Strathclyde region of Scotland for its empirical content and uses multivariate analysis to link infrastructure provision to other spatial attributes which are important in stimulating local economic development.     

裂隙岩体中力学-渗流-传输耦合离散元模拟

深部地下工程包括增强型地热系统、核废料的地下处置、CO₂地下封存、煤炭地下气化等,都涉及到复杂的水-力-化多场耦合过程。全面理解力学过程影响下的溶质(如放射性核素)传输过程是以上各类工程成功建设和安全运行的重要理论基础。本文基于离散裂隙网络模型的思想,采用离散元方法来模拟应力-渗流耦合过程,而溶质传输过程则用粒子追踪法(Particle tracking algorithm)来进行模拟。溶质传输机理主要考虑了单岩石裂隙中的平流(Advection)、弥散(Hydrodynamic dispersion)以及原岩-裂隙之间的扩散(Matrix diffusion)。结果显示,力学过程对溶质传输过程有着显著影响,会明显改变溶质在裂隙网络中的停滞时间、传输路径和位置分布等。当水力梯度较小时,原岩-裂隙之间的扩散过程将是溶质在裂隙网络中停滞时间的决定性因素。     

Data Mining and Knowledge Discovery in Sediment Transport

The means for data collection have never been as advanced as they are today. Moreover, the numerical models we use today have never been so advanced. Feeding and calibrating models against collected measurements, however, represents only a one-way flow: from measurements to the model. The observations of the system can be analyzed further in the search for the information they encode. Such automated search for models accurately describing data constitutes a new direction that can be identified as that of data mining. It can be expected that in the years to come we shall concentrate our efforts more and more on the analysis of the data we acquire from natural or artificial sources and that we shall mine for knowledge from the data so acquired.
Data mining and knowledge discovery aim at providing tools to facilitate the conversion of data into a number of forms, such as equations, that provide a better understanding of the process generating or producing these data. These new models combined with the already available understanding of the physical processes—the theory—result in an improved understanding and novel formulations of physical laws and improved predictive capability.
This article describes the data mining process in general, as well as an application of a data mining technique in the domain of sediment transport. Data related to the concentration of suspended sediment near a bed are analyzed by the means of genetic programming. Machine-induced relationships are compared against formulations proposed by human experts and are discussed in terms of accuracy and physical interpretability.     

加快推进上海市公交优先三年行动计划的几点建议

上海市公交优先三年行动计划的推进时间已过半,但客流增长的任务仅完成了1/5,形势不容乐观。该文分析了公交优先实施战略中存在的线网优化、出行成本、基础设施建设、体制改革等方面的主要问题,并针对性地提出了加快推进上海市公交优先三年行动计划的建议。