A simulation model was proposed to investigate the relationship between train delays and passenger delays and to predict the dynamic passenger distribution in a large-scale rail transit network. It was assumed that th...A simulation model was proposed to investigate the relationship between train delays and passenger delays and to predict the dynamic passenger distribution in a large-scale rail transit network. It was assumed that the time varying original-destination demand and passenger path choice probability were given. Passengers were assumed not to change their destinations and travel paths after delay occurs. CapaciW constraints of train and queue rules of alighting and boarding were taken into account. By using the time-driven simulation, the states of passengers, trains and other facilities in the network were updated every time step. The proposed methodology was also tested in a real network, for demonstration. The results reveal that short train delay does not necessarily result in passenger delays, while, on the contrary, some passengers may get benefits from the short delay. However, large initial train delay may result in not only knock-on train and passenger delays along the same line, but also the passenger delays across the entire rail transit network.展开更多
Optimization of adaptive traffic signal timing is one of the most complex problems in traffic control systems. This paper presents an adaptive transit signal priority （TSP） strategy that applies the parallel genetic...Optimization of adaptive traffic signal timing is one of the most complex problems in traffic control systems. This paper presents an adaptive transit signal priority （TSP） strategy that applies the parallel genetic algorithm （PGA） to optimize adaptive traffic signal control in the presence of TSP. The method can optimize the phase plan, cycle length, and green splits at isolated intersections with consideration for the performance of both the transit and the general vehicles. A VISSIM （VISual SIMulation） simulation testbed was developed to evaluate the performance of the proposed PGA-based adaptive traffic signal control with TSP. The simulation results show that the PGA-based optimizer for adaptive TSP outperformed the fully actuated NEMA control in all test cases. The results also show that the PGA-based optimizer can produce TSP timing plans that benefit the transit vehicles while minimizing the impact of TSP on the general vehicles.展开更多
在对已发表的 Ga As HBT文献的研究中发现 ,其截止频率 f T 的理论计算结果比实验值小很多 ,而相应的文献中并没有给出 f T的计算结果。针对上述问题 ,文中对产生这种差距的原因进行了分析 ,认为由于速度过冲效应的存在 ,使得电子并非...在对已发表的 Ga As HBT文献的研究中发现 ,其截止频率 f T 的理论计算结果比实验值小很多 ,而相应的文献中并没有给出 f T的计算结果。针对上述问题 ,文中对产生这种差距的原因进行了分析 ,认为由于速度过冲效应的存在 ,使得电子并非以饱和速度 Vsat渡越 BC结耗尽区 ,而是以更高的速度运动。基于上述理论 ,对产生截止频率误差的 BC结耗尽区电子渡越时间τsc进行了修正。利用修正后的公式对文献中的数据进行了重新计算 ,得到了令人满意的结果。展开更多
基金Project(51008229)supported by the National Natural Science Foundation of ChinaProject supported by Key Laboratory of Road and Traffic Engineering of Tongji University,China
文摘A simulation model was proposed to investigate the relationship between train delays and passenger delays and to predict the dynamic passenger distribution in a large-scale rail transit network. It was assumed that the time varying original-destination demand and passenger path choice probability were given. Passengers were assumed not to change their destinations and travel paths after delay occurs. CapaciW constraints of train and queue rules of alighting and boarding were taken into account. By using the time-driven simulation, the states of passengers, trains and other facilities in the network were updated every time step. The proposed methodology was also tested in a real network, for demonstration. The results reveal that short train delay does not necessarily result in passenger delays, while, on the contrary, some passengers may get benefits from the short delay. However, large initial train delay may result in not only knock-on train and passenger delays along the same line, but also the passenger delays across the entire rail transit network.
文摘Optimization of adaptive traffic signal timing is one of the most complex problems in traffic control systems. This paper presents an adaptive transit signal priority （TSP） strategy that applies the parallel genetic algorithm （PGA） to optimize adaptive traffic signal control in the presence of TSP. The method can optimize the phase plan, cycle length, and green splits at isolated intersections with consideration for the performance of both the transit and the general vehicles. A VISSIM （VISual SIMulation） simulation testbed was developed to evaluate the performance of the proposed PGA-based adaptive traffic signal control with TSP. The simulation results show that the PGA-based optimizer for adaptive TSP outperformed the fully actuated NEMA control in all test cases. The results also show that the PGA-based optimizer can produce TSP timing plans that benefit the transit vehicles while minimizing the impact of TSP on the general vehicles.
文摘在对已发表的 Ga As HBT文献的研究中发现 ,其截止频率 f T 的理论计算结果比实验值小很多 ,而相应的文献中并没有给出 f T的计算结果。针对上述问题 ,文中对产生这种差距的原因进行了分析 ,认为由于速度过冲效应的存在 ,使得电子并非以饱和速度 Vsat渡越 BC结耗尽区 ,而是以更高的速度运动。基于上述理论 ,对产生截止频率误差的 BC结耗尽区电子渡越时间τsc进行了修正。利用修正后的公式对文献中的数据进行了重新计算 ,得到了令人满意的结果。
