The theory of complex networks was used to classify public transport networks into public transportation route networks, public transportation transfer networks, and bus station networks. The practical significance of...The theory of complex networks was used to classify public transport networks into public transportation route networks, public transportation transfer networks, and bus station networks. The practical significance of the network parameters was then analyzed. The public transport networks in Langfang, Jining, and Dalian were then chosen as specific research cases. The results show that the public transportation networks have the characteristics of complex networks, In addition, the urban transportation network parameters all significantly affect the accessibility, convenience, and terrorist security capability of the urban public transportation network. The results link the findings with the actual situations to explore means to solve transportation system problems.展开更多
In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The vertices of the networks(i.e., the bus stops) are determined by means of the fuzzy clusteri...In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The vertices of the networks(i.e., the bus stops) are determined by means of the fuzzy clustering method. The arcs (i.e., the paths of the public transportation) can be set up by using the shortest path model in the time sense or the 0 1 integer programming method.Applying the statistics method, we can calculate the parameters(such as the passenger flow's distribution, passenger flow's transition probability, mean waiting time for the bus etc. ) of the public transportation network. In this paper, we suggest to divide the network into two or three stages to implement the public transportation system in the form of ``frog jumping' fast transfer and ``permeation' fast dispersion.Combining the computer simulation and the evaluation of the achievement and effect of public transportation system, we modify the model so as to solve the public transportation problem better.展开更多
对公交枢纽(public transport hub, PTH)进行最优并网规划是提升城市客运服务效率及配电网运行效率的重要途径。为此,在深入分析智能公交枢纽与配电网交互机理的基础上,分别考虑正常和故障情况下PTH需求响应对系统的影响,提出了一种面...对公交枢纽(public transport hub, PTH)进行最优并网规划是提升城市客运服务效率及配电网运行效率的重要途径。为此,在深入分析智能公交枢纽与配电网交互机理的基础上,分别考虑正常和故障情况下PTH需求响应对系统的影响,提出了一种面向促进配网可靠性和经济性提升的PTH三层规划优化模型。该模型上层以配网投资运行总成本最小为目标,优化PTH布设位置以及电动公交/充电桩布置数量。中层在满足公交服务需求的前提下以正常运行PTH从配网购电最小为目标,优化发车间隔和公交车充电计划。下层以配网故障情况下系统停电损失最小为目标,优化故障时发车间隔、负荷削减量以及电动公交的发车状态和充放电功率。设计多层求解算法实现上述模型的高效求解。最后,基于IEEE33节点系统的仿真结果验证了所提规划方法能够充分挖掘PTH资源的灵活性潜力,兼顾配网运行经济性和可靠性。展开更多
At the beginning of the twentieth century, the United States was leading in the public transit sector, but following World War II, private automobiles became more affordable and gained popularity. Transportation infra...At the beginning of the twentieth century, the United States was leading in the public transit sector, but following World War II, private automobiles became more affordable and gained popularity. Transportation infrastructure investments that increased road capacity further facilitated the increase in automobile use at the expense of reduced public transit ridership. With the increase of dependency on automobiles and the continuing growth of private automobile ownership and use, various problems became major challenges in big cities of USA. These include traffic congestion, air pollution, road and parking infrastructure costs, energy consumption, traffic safety, fewer mobility options for the non-drivers, and a decline in the image and use of public transit. This study uses a medium sized city, Birmingham as a case study to investigate the potential of public transit to reduce automobile trips and in turn improve the overall performance of the road network by addressing the abovementioned challenges. An agent-based simulation model was developed for the Birmingham metropolitan region using the Multi-agent Transport Simulation (MATSim) platform. Three scenarios were considered with gradually increased transit ridership to identify the benefits of increased public transit. Traffic volume, network average speed, and travel times were used as performance measures for the evaluation of the designated scenarios. Results suggest that modal shifts toward public transit and reduction in travel demand for an automobile can result in improvements in speed and travel time for all users. Therefore, investments for improving transit quality and frequency of service, as well as campaigns to improve the image of public transit and make it a mode of choice for transportation users can increase transit ridership and, in turn, improve network operations, thus are deemed worthy for medium sized cities.展开更多
为提高公交网络运营稳定性,保障乘客顺利出行,需准确识别公交网络中的重要节点并进行重点保护。鉴于此,考虑公交网络节点相互影响的网络拓扑特性和现实特征,提出了DeB(Degree and edge Betweenness)节点重要性识别算法,以边介数和客流...为提高公交网络运营稳定性,保障乘客顺利出行,需准确识别公交网络中的重要节点并进行重点保护。鉴于此,考虑公交网络节点相互影响的网络拓扑特性和现实特征,提出了DeB(Degree and edge Betweenness)节点重要性识别算法,以边介数和客流表示节点相互影响力的大小,同时,引入节点n阶吸引度作为衡量节点重要性的指标。最后,以宁波市公交网络为例,研究比较了在基于DeB算法、度中心性算法、介数中心性算法的模拟蓄意攻击下,网络效率和最大连通子图的变化情况,以验证算法的有效性和精确性。结果显示,基于DeB算法得到的节点1阶吸引度的蓄意攻击对网络效率和最大连通子图的影响最大,即对重要节点识别的精确性越高,且节点吸引度阶数越高,算法精确性越低;与度中心性、介数中心性相比,节点1阶吸引度的精确性更高,表明DeB算法得到的节点1阶吸引度可更准确地衡量节点的重要性。展开更多
文摘The theory of complex networks was used to classify public transport networks into public transportation route networks, public transportation transfer networks, and bus station networks. The practical significance of the network parameters was then analyzed. The public transport networks in Langfang, Jining, and Dalian were then chosen as specific research cases. The results show that the public transportation networks have the characteristics of complex networks, In addition, the urban transportation network parameters all significantly affect the accessibility, convenience, and terrorist security capability of the urban public transportation network. The results link the findings with the actual situations to explore means to solve transportation system problems.
文摘In this paper, the open queueing network model is proposed for solving the problem of public transportation in cities. The vertices of the networks(i.e., the bus stops) are determined by means of the fuzzy clustering method. The arcs (i.e., the paths of the public transportation) can be set up by using the shortest path model in the time sense or the 0 1 integer programming method.Applying the statistics method, we can calculate the parameters(such as the passenger flow's distribution, passenger flow's transition probability, mean waiting time for the bus etc. ) of the public transportation network. In this paper, we suggest to divide the network into two or three stages to implement the public transportation system in the form of ``frog jumping' fast transfer and ``permeation' fast dispersion.Combining the computer simulation and the evaluation of the achievement and effect of public transportation system, we modify the model so as to solve the public transportation problem better.
文摘对公交枢纽(public transport hub, PTH)进行最优并网规划是提升城市客运服务效率及配电网运行效率的重要途径。为此,在深入分析智能公交枢纽与配电网交互机理的基础上,分别考虑正常和故障情况下PTH需求响应对系统的影响,提出了一种面向促进配网可靠性和经济性提升的PTH三层规划优化模型。该模型上层以配网投资运行总成本最小为目标,优化PTH布设位置以及电动公交/充电桩布置数量。中层在满足公交服务需求的前提下以正常运行PTH从配网购电最小为目标,优化发车间隔和公交车充电计划。下层以配网故障情况下系统停电损失最小为目标,优化故障时发车间隔、负荷削减量以及电动公交的发车状态和充放电功率。设计多层求解算法实现上述模型的高效求解。最后,基于IEEE33节点系统的仿真结果验证了所提规划方法能够充分挖掘PTH资源的灵活性潜力,兼顾配网运行经济性和可靠性。
文摘At the beginning of the twentieth century, the United States was leading in the public transit sector, but following World War II, private automobiles became more affordable and gained popularity. Transportation infrastructure investments that increased road capacity further facilitated the increase in automobile use at the expense of reduced public transit ridership. With the increase of dependency on automobiles and the continuing growth of private automobile ownership and use, various problems became major challenges in big cities of USA. These include traffic congestion, air pollution, road and parking infrastructure costs, energy consumption, traffic safety, fewer mobility options for the non-drivers, and a decline in the image and use of public transit. This study uses a medium sized city, Birmingham as a case study to investigate the potential of public transit to reduce automobile trips and in turn improve the overall performance of the road network by addressing the abovementioned challenges. An agent-based simulation model was developed for the Birmingham metropolitan region using the Multi-agent Transport Simulation (MATSim) platform. Three scenarios were considered with gradually increased transit ridership to identify the benefits of increased public transit. Traffic volume, network average speed, and travel times were used as performance measures for the evaluation of the designated scenarios. Results suggest that modal shifts toward public transit and reduction in travel demand for an automobile can result in improvements in speed and travel time for all users. Therefore, investments for improving transit quality and frequency of service, as well as campaigns to improve the image of public transit and make it a mode of choice for transportation users can increase transit ridership and, in turn, improve network operations, thus are deemed worthy for medium sized cities.
文摘为提高公交网络运营稳定性,保障乘客顺利出行,需准确识别公交网络中的重要节点并进行重点保护。鉴于此,考虑公交网络节点相互影响的网络拓扑特性和现实特征,提出了DeB(Degree and edge Betweenness)节点重要性识别算法,以边介数和客流表示节点相互影响力的大小,同时,引入节点n阶吸引度作为衡量节点重要性的指标。最后,以宁波市公交网络为例,研究比较了在基于DeB算法、度中心性算法、介数中心性算法的模拟蓄意攻击下,网络效率和最大连通子图的变化情况,以验证算法的有效性和精确性。结果显示,基于DeB算法得到的节点1阶吸引度的蓄意攻击对网络效率和最大连通子图的影响最大,即对重要节点识别的精确性越高,且节点吸引度阶数越高,算法精确性越低;与度中心性、介数中心性相比,节点1阶吸引度的精确性更高,表明DeB算法得到的节点1阶吸引度可更准确地衡量节点的重要性。
