The Experts below are selected from a list of 14499 Experts worldwide ranked by ideXlab platform
James H. Bookbinder - One of the best experts on this subject based on the ideXlab platform.
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the european freight Railway System as a hub and spoke network
Transportation Research Part A-policy and Practice, 2007Co-Authors: Seung Ju Jeong, James H. BookbinderAbstract:This paper addresses a hub-and-spoke network problem for railroad freight, where a central planner is to find transport routes, frequency of service, length of trains to be used, and transportation volume. Hub-and-spoke networks, often found in air freight, have not been favoured by Railways in the past. Such a structure could be profitable, however, if there exist concentrated freight flows on some service links. We formulate a linear integer programming model whose objective function includes not only the typical operational cost, but also cost due to the transit time spent by freight in the network. We then develop heuristic algorithms to solve large scale instances occurring in rail freight Systems in France plus Italy; Germany; and a 10-country European network. By assuming that every node is equipped with consolidation capability, we let the final solution naturally reveal potential hub locations, the impact of several of which is studied by sensitivity analysis.
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The European freight Railway System as a hub-and-spoke network
Transportation Research Part A: Policy and Practice, 2007Co-Authors: Seung Ju Jeong, Chi Guhn Lee, James H. BookbinderAbstract:This paper addresses a hub-and-spoke network problem for railroad freight, where a central planner is to find transport routes, frequency of service, length of trains to be used, and transportation volume. Hub-and-spoke networks, often found in air freight, have not been favoured by Railways in the past. Such a structure could be profitable, however, if there exist concentrated freight flows on some service links. We formulate a linear integer programming model whose objective function includes not only the typical operational cost, but also cost due to the transit time spent by freight in the network. We then develop heuristic algorithms to solve large scale instances occurring in rail freight Systems in France plus Italy; Germany; and a 10-country European network. By assuming that every node is equipped with consolidation capability, we let the final solution naturally reveal potential hub locations, the impact of several of which is studied by sensitivity analysis. © 2006 Elsevier Ltd. All rights reserved.
Seung Ju Jeong - One of the best experts on this subject based on the ideXlab platform.
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the european freight Railway System as a hub and spoke network
Transportation Research Part A-policy and Practice, 2007Co-Authors: Seung Ju Jeong, James H. BookbinderAbstract:This paper addresses a hub-and-spoke network problem for railroad freight, where a central planner is to find transport routes, frequency of service, length of trains to be used, and transportation volume. Hub-and-spoke networks, often found in air freight, have not been favoured by Railways in the past. Such a structure could be profitable, however, if there exist concentrated freight flows on some service links. We formulate a linear integer programming model whose objective function includes not only the typical operational cost, but also cost due to the transit time spent by freight in the network. We then develop heuristic algorithms to solve large scale instances occurring in rail freight Systems in France plus Italy; Germany; and a 10-country European network. By assuming that every node is equipped with consolidation capability, we let the final solution naturally reveal potential hub locations, the impact of several of which is studied by sensitivity analysis.
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The European freight Railway System as a hub-and-spoke network
Transportation Research Part A: Policy and Practice, 2007Co-Authors: Seung Ju Jeong, Chi Guhn Lee, James H. BookbinderAbstract:This paper addresses a hub-and-spoke network problem for railroad freight, where a central planner is to find transport routes, frequency of service, length of trains to be used, and transportation volume. Hub-and-spoke networks, often found in air freight, have not been favoured by Railways in the past. Such a structure could be profitable, however, if there exist concentrated freight flows on some service links. We formulate a linear integer programming model whose objective function includes not only the typical operational cost, but also cost due to the transit time spent by freight in the network. We then develop heuristic algorithms to solve large scale instances occurring in rail freight Systems in France plus Italy; Germany; and a 10-country European network. By assuming that every node is equipped with consolidation capability, we let the final solution naturally reveal potential hub locations, the impact of several of which is studied by sensitivity analysis. © 2006 Elsevier Ltd. All rights reserved.
Gildong Kim - One of the best experts on this subject based on the ideXlab platform.
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Capacity optimization of the supercapacitor energy storages on DC Railway System using a Railway powerflow algorithm
International Journal of Innovative Computing, Information and Control, 2011Co-Authors: Hanmin Lee, Jiyoung Song, Gilsoo Jang, Changmu Lee, Gildong KimAbstract:The electric Railway System is one of the most peculiar power Systems of which the location and power of electrical load are continuously variable. The variance of the location and power of the vehicle changes the participation factor of each substation for the vehicle and the sign and magnitude of the load current, respectively. Especially, on the substation feeder, there is huge voltage uctuation generated by the regenerative energy due to the braking vehicles. This regenerative energy is closely related with the energy efficiency since the surplus energy cannot be utilized and dissipated in the resistor. To improve energy efficiency of the Railway System and utilize the surplus regenerative energy, the application of energy storage has been studied. In this paper, a DC Railway powerow algorithm considering storages is developed to analyze the Railway System with storages and to calculate the optimal power and storage capacity of them. The Seoul Metro Line 7 is selected for the test System and simulated to verify the effect of storages. Also, the optimal power and storage capacity of each SCES is calculated. © 2011.
Gilsoo Jang - One of the best experts on this subject based on the ideXlab platform.
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Capacity optimization of the supercapacitor energy storages on DC Railway System using a Railway powerflow algorithm
International Journal of Innovative Computing, Information and Control, 2011Co-Authors: Hanmin Lee, Jiyoung Song, Gilsoo Jang, Changmu Lee, Gildong KimAbstract:The electric Railway System is one of the most peculiar power Systems of which the location and power of electrical load are continuously variable. The variance of the location and power of the vehicle changes the participation factor of each substation for the vehicle and the sign and magnitude of the load current, respectively. Especially, on the substation feeder, there is huge voltage uctuation generated by the regenerative energy due to the braking vehicles. This regenerative energy is closely related with the energy efficiency since the surplus energy cannot be utilized and dissipated in the resistor. To improve energy efficiency of the Railway System and utilize the surplus regenerative energy, the application of energy storage has been studied. In this paper, a DC Railway powerow algorithm considering storages is developed to analyze the Railway System with storages and to calculate the optimal power and storage capacity of them. The Seoul Metro Line 7 is selected for the test System and simulated to verify the effect of storages. Also, the optimal power and storage capacity of each SCES is calculated. © 2011.
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Fault analysis of Korean AC electric Railway System
Electric Power Systems Research, 2006Co-Authors: Sehchan Oh, Gilsoo Jang, Sae-hyuk KwonAbstract:This paper presents the fault analysis of Korean AC electric Railway System. The AC electric Railway System is modeled by PSCAD/EMTDC tool. This System model is composed of the Scott-transformer, the autotransformer, the running rails, the protection wires, the feeders, messenger wires and contact wires, etc. After obtaining the models of the fundamental elements describing Korean AC electric Railway System, studies for the steady state and fault conditions are carried out. Simulation result and hand calculation for the fault analysis are compared with field data. Finally, we acquire the specific characteristic of Korean AC electric Railway System. The proposed model would be a powerful tool for designing and planning Korean AC electric Railway System.
Hanmin Lee - One of the best experts on this subject based on the ideXlab platform.
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Capacity optimization of the supercapacitor energy storages on DC Railway System using a Railway powerflow algorithm
International Journal of Innovative Computing, Information and Control, 2011Co-Authors: Hanmin Lee, Jiyoung Song, Gilsoo Jang, Changmu Lee, Gildong KimAbstract:The electric Railway System is one of the most peculiar power Systems of which the location and power of electrical load are continuously variable. The variance of the location and power of the vehicle changes the participation factor of each substation for the vehicle and the sign and magnitude of the load current, respectively. Especially, on the substation feeder, there is huge voltage uctuation generated by the regenerative energy due to the braking vehicles. This regenerative energy is closely related with the energy efficiency since the surplus energy cannot be utilized and dissipated in the resistor. To improve energy efficiency of the Railway System and utilize the surplus regenerative energy, the application of energy storage has been studied. In this paper, a DC Railway powerow algorithm considering storages is developed to analyze the Railway System with storages and to calculate the optimal power and storage capacity of them. The Seoul Metro Line 7 is selected for the test System and simulated to verify the effect of storages. Also, the optimal power and storage capacity of each SCES is calculated. © 2011.
