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731.
Improvements in geographical information systems, the wider availability of high-resolution digital data and more sophisticated econometric techniques have all contributed to increasing academic interest and activity in long-term impacts of transport infrastructure networks (TINs) on land use (LU). This paper provides a systematic review of recent empirical evidence from the USA, Europe and East Asia, classified regarding the type of transport infrastructure (road or rail), LU indicator (land cover, population or employment density, development type) and outcome (significance, relationship’s direction) as well as influential exogenous factors. Proximity to the rail network is generally associated with population growth (particularly soon after the development of railway infrastructure), conversion to residential uses and the development of higher residential densities. Meanwhile, proximity to the road network is frequently associated with increases in employment densities as well as the conversion of land to a variety of urban uses including commercial and industrial development. Compared with road infrastructure, the impact of rail infrastructure is often less significant for land cover or population and employment density change. The extent of TINs’ impact on LU over time can be explained by the saturation in TIN-related accessibility and LU development. 相似文献
732.
Modelling public transport on‐board congestion: comparing schedule‐based and agent‐based assignment approaches and their implications
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Transit systems are subject to congestion that influences system performance and level of service. The evaluation of measures to relieve congestion requires models that can capture their network effects and passengers' adaptation. In particular, on‐board congestion leads to an increase of crowding discomfort and denied boarding and a decrease in service reliability. This study performs a systematic comparison of alternative approaches to modelling on‐board congestion in transit networks. In particular, the congestion‐related functionalities of a schedule‐based model and an agent‐based transit assignment model are investigated, by comparing VISUM and BusMezzo, respectively. The theoretical background, modelling principles and implementation details of the alternative models are examined and demonstrated by testing various operational scenarios for an example network. The results suggest that differences in modelling passenger arrival process, choice‐set generation and route choice model yield systematically different passenger loads. The schedule‐based model is insensitive to a uniform increase in demand or decrease in capacity when caused by either vehicle capacity or service frequency reduction. In contrast, nominal travel times increase in the agent‐based model as demand increases or capacity decreases. The marginal increase in travel time increases as the network becomes more saturated. Whilst none of the existing models capture the full range of congestion effects and related behavioural responses, existing models can support different planning decisions. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
733.
研究车载交通流诱导系统的最优路径选择问题。采用广义路阻的定义,考虑了驾驶员在路径选择中的不同要求,并借助一种具有暂态混沌和时变增益的神经网络(NNTCTG),针对最优路径选择问题设计了神经网络结构,构造了能量函数,提出了一种能够满足不同出行者偏好的最优路径选择算法。所提出的算法具有很多优良特性,即暂态混沌特性和平稳收敛性,能有效地避免传统Hopfield神经网络极易陷入局部极值的缺陷。它通过短暂的倒分叉过程,能很快进入稳定收敛状态。仿真结果表明,NNTCTG求解指定起讫点对之间的最优路径问题时,总能收敛到全局最优,同时具有更高的搜索效率。 相似文献
734.
彭勇 《重庆交通大学学报(自然科学版)》2008,27(3):479-483
探讨了第三方物流服务商综合前向及逆向物流活动降低物流总成本的问题,建立了物流服务一体化网络系统模型。模型允许两点实际距离非直线距离,并假定市场需求及产品返回数量随机分布。由于该问题为NP-hard,设计了遗传算法并讨论了算法收敛性,最后给出了一个数值算例。 相似文献
735.
The advantages offered by the electronic component LED (Light Emitting Diode) have resulted in a quick and extensive application
of this device in the replacement of incandescent lights. In this combined application, however, the relationship between
the design variables and the desired effect or result is very complex and renders it difficult to model using conventional
techniques. This paper consists of the development of a technique using artificial neural networks that makes it possible
to obtain the luminous intensity values of brake lights using SMD (Surface Mounted Device) LEDs from design data. This technique
can be utilized to design any automotive device that uses groups of SMD LEDs. The results of industrial applications using
SMD LED are presented to validate the proposed technique. 相似文献
736.
Jianjun WU Ziyou GAO Huijun SUN 《Journal of Transportation Systems Engineering and Information Technology》2008,8(2):69-74
Many transportation processes and behaviors, from traffic flow movement to crowd stampede and natural fluxion, are related to the action of agents. We have investigated and quantified the interplay between topologies and the individual behavior modes (unselfish and selfish) in equilibrium urban traffic networks. In this paper, the unselfish and selfish behavior correspond to the system optimum (SO) and user equilibrium in the traffic assignment. A significant finding is that the fractions of flow for two cases are constants in the minimum spanning tree where a large number of transport task is shouldered. In addition, we find that the upper bound of unselfish behavior is limited and ordinal for different network topologies which, therefore, indicates large investment on SO is not an effective method to alleviate the traffic congestion caused by selfish behavior. We report the phase transition from free traffic to congestion and derive a general scaling relationship between the congestion and the flow in arbitrary network topologies suggesting that the result might be practically useful for designing urban traffic networks. 相似文献
737.
刘堂州 《石家庄铁道学院学报》2008,21(1):87-89
根据高速铁路道岔铺设施工要求,提出了一套结构简单、成本低廉而且只须依靠人力就可完成设备本身的拆装并能满足道岔对位、调试的道岔移动小车。介绍了道岔移动小车的主要结构和技术参数,并简述了施工工艺,最后进行了技术经济分析。 相似文献
738.
移动式海岸卸载系统三维运动响应研究 总被引:1,自引:0,他引:1
移动式海岸卸载系统是一种由多个半潜式浮箱单元拼接而成的连岸型海上装卸装备,由于其可以靠泊各类中小型舰艇和民用船舶,并可拆卸转移,因而具有很高的适用性和灵活性.文章在深入分析国内外海洋多浮体三维运动响应计算方法的基础上,对近海移动式卸载系统进行了建模.并采用多浮体有限水深三维势流理论和谱分析方法对其在海浪作用下的运动性能进行了研究,重点分析工作海况下浪向的改变对卸载系统浮箱单元三维运动响应的影响,并将数值计算结果与实验结果进行了对比分析.研究结果表明,文中所采用的理论计算方法可以用于预报移动式卸载系统的运动性能,其计算结果可以作为设计锚链和模块间连接器的依据以及确定系统工作海域、海况的参考. 相似文献
739.
基于LonWorks技术的摆式列车倾摆测控网络试验研究 总被引:1,自引:0,他引:1
就LonWorks技术的摆式列车倾摆测控网络系统中的应用进行了研究,试验表明采用LonWorks技术构成的摆式列车倾摆测网络系统具有高的可靠性和好的实时性,该研究为LonWorks技术在摆式列车倾摆测控系统中的最终成功应用提供了理论和试验依据。 相似文献
740.
IntroductionHMM method and neural networks as a feasiblemethod have been used in speech recognitionsystem for several years,many improved meth-ods are still being discussed and proposed to en-hance its performance.On the basis of tradition-al HMM method and selection mechanism ,anew CSL algorithm ( competitive and selectivelearning neural networks) is proposed in this pa-per,which enables the system to avoid localminimum and have high recognition rate usingwith HMM and PSHNN.Isodistortio… 相似文献