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Spillback congestion in dynamic traffic assignment: A macroscopic flow model with time-varying bottlenecks 总被引:1,自引:0,他引:1
Guido Gentile Lorenzo Meschini Natale Papola 《Transportation Research Part B: Methodological》2007,41(10):1114-1138
In this paper, we propose a new model for the within-day Dynamic Traffic Assignment (DTA) on road networks where the simulation of queue spillovers is explicitly addressed, and a user equilibrium is expressed as a fixed-point problem in terms of arc flow temporal profiles, i.e., in the infinite dimension space of time’s functions. The model integrates spillback congestion into an existing formulation of the DTA based on continuous-time variables and implicit path enumeration, which is capable of explicitly representing the formation and dispersion of vehicle queues on road links, but allows them to exceed the arc length. The propagation of congestion among adjacent arcs will be achieved through the introduction of time-varying exit and entry capacities that limit the inflow on downstream arcs in such a way that their storage capacities are never exceeded. Determining the temporal profile of these capacity constraints requires solving a system of spatially non-separable macroscopic flow models on the supply side of the DTA based on the theory of kinematic waves, which describe the dynamic of the spillback phenomenon and yield consistent network performances for given arc flows. We also devise a numerical solution algorithm of the proposed continuous-time formulation allowing for “long time intervals” of several minutes, and give an empirical evidence of its convergence. Finally, we carry out a thorough experimentation in order to estimate the relevance of spillback modeling in the context of the DTA, compare the proposed model in terms of effectiveness with the Cell Transmission Model, and assess the efficiency of the proposed algorithm and its applicability to real instances with large networks. 相似文献
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企业的组织能力理论刍论 总被引:1,自引:0,他引:1
陈然方 《上海交通大学学报(哲学社会科学版)》2004,12(1):66-70
本文认为人在理性的动机之下,会表现出信任或机会主义的行为倾向。企业的发展壮大需要代理人之间的信任与合作,而引发信任抑制机会主义需要企业具有“组织能力”,即“签订”组织内部的默契等隐含契约的能力。组织能力的提高是企业进行规模扩张的必要条件。具有强大的组织能力的企业将主动进行边界扩张以寻求规模和企业价值的最大化,而不是如传统的交易成本经济学所预期的那样只是被动地为节约交易成本而进行边界决策。 相似文献
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利用组合差商法对色散方程ut=auxxx的初边值问题,构造了两组带参数两层四点偏心隐式差分格式PL2,PR2,其截断误差为ο(τ h2),稳定性随参数变化而变化。特殊的,若令某个节点前的系数为0,则得到二阶的半显格式。最后的数例既验证了理论分析的正确性,也说明了特取参数可以增强格式应用的灵活性。 相似文献
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铁路车辆无改编通过技术站的节省时间是铁路车流组织的重要参考依据,其准确与否直接关系到列车编组计划质量的优劣.提出了车辆在改编过程中除了产生改编时间、改编费用的显性成本以外,还产生车轮、车钩、车体及货物损伤等隐性成本,并探讨了该隐性成本的量化途径.分析了铁路车辆改编参数计算的要素,在考虑车辆改编隐性成本的基础上对传统改编参数进行了修正,并设计了一个单组列车编组方案优化的算例.分析表明车辆改编隐性成本应当纳入改编参数的计算之中,其对列车编组计划优化的影响不容忽视. 相似文献
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叙述者在叙事时总要表现出对人物和事件的态度,任何叙述文本都避免不了叙述者的评论干预。现代文学作品对于评论干预的要求越来越高,评论干预的研究也因此更加不容忽视。文章在综述国内外该领域研究现状的基础上,试图指出评论干预研究的问题和不足所在。首先,学界对于评论、干预以及评论干预三者之间关系缺乏明确界定。其次,评论干预研究多集中在显性评论干预,对于隐性评论干预关注不够。再者,研究多聚焦具体作品的评论干预分析探讨,鲜见评论干预的系统理论探究。最后,评论干预在叙事进程中发挥的作用未给予充分重视。 相似文献
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By applying the auxiliary variational principle technique, the existence of solutions for a new class of generalized mixed implicit quasi-variational-like inequalities and the convergence criteria of a new iterative algorithm to compute approximate solutions are proved in Hilbert spaces. The obtained result is a improvement over and generalization of the main theorem proposed by Ding. 相似文献
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故障车停车线的布局设置对城市轨道交通线路工程的造价和建成后的运营均有重要影响. 本文从建设和运营两方面对城市轨道交通故障车停车线的布局设置方案的优化进行了研究,介绍了城市轨道交通中故障车停车线设置研究的现状,从城市轨道交通系统运营角度分析了故障车处理及救援的基本流程;参考地铁设计规范及运营要求,建立了以考虑故障救援效果和工程造价二者为优化目标的故障线布局设置多目标0-1规划模型;并结合模型实际背景设计了隐枚举求解方法;运用某条城市轨道交通线路的设计数据对模型和求解算法进行了验证. 结果表明,该方法能够快速、合理地得出故障车停车线的布局设置方案. 相似文献
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