• Proceedings of the KSME Conference
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• 2001.06b
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• pp.571-577
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• 2001

In this paper, the dynamic response of the pantograph system that supplies electrical power to a high-speed rail vehicle were investigated. The analyses of the catenary based on the Finite Element Method (FEM) is executed to develop a pantograph fits well in high-speed focused on the dynamic characteristic analysis of the pantograph system. By simulation of the pantograph-catenary system, the static deflection of the catenary, the stiffness variation in contact lines, the dynamic response of the catenary undergoing constant moving load and the contact force analysis were executed. By the pantograph-catenary analysis, the design parameters of a pantograph could be optimized. For more improving the dynamic characteristics of the pantograph, the active-pantograph was investigated by controlling a contact force. The active pantograph showed the better performance compared to the parameter-optimized. However, the parameter-optimized pantograph would be acceptable for a high-speed rail vehicle through the design-parameter analysis.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.442-449
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• 2000

Before the complete construction of new high-speed line between Seoul and Pusan, KTX is going to operate on both new high-speed line between Seoul and Daegu and electrified conventional lines between Daegu and Pusan. Then, the wheels of KTX are going to operate on various rails such as KS50N and KS60 of conventional line as well as UIC60 of high-speed line. Also, conventional line will have a mixed traffic mode with various types of trains operating on it, such as Saemaul and Mugunghwa. Hence, this study reviews the wear phenomena of wheels and rails in geometrical point of view by comparing their profiles. The analyses of the results show that because UIC60 rail is designed for KTX, KS50N rail whose profile is similar to that of UIC60 will not have any impact on the shape of wheel wear. On the other hand, KS60 rail is expected to have partial wear on both the flange of KTX wheel and the gauge corner of the rail in the initial stages. However, the operation of the trains whose wheels have 1/20 conicity will cause partial sidewear on the inside of the rail and the movement of the contact point between KTX wheel and the rail toward the inside of the track. As a result, the flange wear of KTX wheel will be reduced and the formation of wear-equilibrium profile will be faster.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.396-404
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• 2009

With developing the next generation high speed railway, there need to be plans to make sure of running safety though researchs on the crack and break of rail by rolling contact fatigue. Therefore, this study performed the parametric analysis effecting on the fatigue life of rail using simplified equations. It analyzed the internal stress of rail according to the track quality, train velocity, wheel radius, track stiffness, sleeper space, wheel load. For the more, via the finite element method, it analyzed shear force on the rail head which could be changed by the early length of crack, angle of crack and temperature. As a result, this study continued the main parameter effecting on the fatigue life of rail.

• Proceedings of the KSR Conference
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• 2002.10a
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• pp.54-59
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• 2002

In general, the aluminum extrusions are used to the light construction of the high speed rail vehicle structures. However, the research works ok the crashworthy design of the high speed rail vehicle structures are not published sufficiently because the crash test of high speed rail vehicle structures costs high and is complicated. So, a method that can predict crash characteristics of a large size structure like a high speed tail vehicle should be suggested. In this study, the scale model studies are performed to predict the impact energy absorption characteristics of full scale model. In the first place, we verified the theory of scale law using FE-simulation from the crashworthiness point of view. Secondly, we performed the crush test using scale model, made of aluminum sub structure. As a result, we could predict the crash characteristics using scale model by 10∼20% error.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.667-672
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• 2013

This paper presents the development of a condition monitoring system that monitors the operating conditions of a reduction unit, such as the bearing temperature, gearbox vibration, and gear oil deterioration, and notifies the operator of potential problems or abnormal conditions. A series of field tests on high-speed rail and conventional lines was performed to identify the characteristics of temperature rise and vibration levels on the reduction unit during operation. The monitoring system was designed based on the proper sensor selection, measurement method, and signal analysis to optimize the interface with the operating system of high-speed trains. Application of this monitoring system to high-speed trains will play an important role in their proper maintenance and safe operation.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.59-69
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• 2014

Recently, the building of an intermodal transportation system has become the most important policy in the establishment of a national-wide sustainable transport system. In the case of rail and public transport, an intermodal connecting improvement policy is essential due to the lack of trip completeness. In particular, high-speed rail has brought dramatic changes to the transportation system in Korea and the idea of high-speed rail stations as major transportation nodes to be linked to various travel modes needs to be analyzed in terms of an intermodal network. Thus, this study proposes a new connectivity analysis method to objectively and quantitatively evaluate intermodal connecting performance for high-speed rail in terms of an intermodal network around high-speed rail stations. Seoul, Busan, Ulsan, and Sin-gyeongju stations were designated for a range of spatial analyses; detailed connecting performance indexes of travel modes connecting high-speed rail stations, and the influence sphere of these stations are analyzed, except for internal transfer facilities. Finally, this study proposes a connectivity analysis method that applies the structural equation model and develops a connectivity index.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1164-1169
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• 2014

Recently, an interest in a hybrid system combining only the merits of the conventional wheel-rail system and Maglev propulsion system is growing as an alternative to high-speed maglev train. This hybrid-type system is based on wheel-rail method, but it enables to overcome the speed limitation by adhesion because it is operated by a non-contact method using a linear motor as a propulsion system and reduce the overall construction costs by its compatibility with the conventional railway systems. Therefore, the design and characteristic analysis of a coreless-type superconducting Linear Synchronous Motor (LSM) for 600km/h very high speed railway system are conducted in this paper. The designed coreless-type superconducting LSMs are the distributed winding model, the concentrated 1 layer winding model and the concentrated 2 layer winding model, respectively. In addition, the characteristic comparison studies on each LSM are conducted.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.183-190
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• 2009

In order to improve continuous success and stabilization of high-speed rail in the future, Using Frequency of high-speed rail should be enhanced by improving satisfaction of high-speed rail passenger. High-speed rail is needed to hold the priority in competition means by comparing the traits of service of domestic air lines. This study utilizes structural equation modeling to develop model for estimating factors influencing to service through conducting survey questionnaire. It also uses reliability analysis, correlation analysis, factor analysis to examine the rationalization of items and to establish hypothesis of this research. The results show that KTX contains 'inner service' item that is considered to be ameliorated and that domestic airline present low performance of 'outer service' item. In other words, moving section which partly is under a limited condition is needed to be improved. In addition, access to airport and transfer to other transportations have to be improved as they show the lowest satisfaction.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.556-563
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• 1998

Railway bridges have a significant effect on the stress and displacement of continuous welded rail(CWR). Longitudinal compression force at high temperature, combined breaking or acceleration forces can introduce track buckling. On the other hand, longitudinal tensile forces, associated with low temperatures, in combination with breaking forces may break rail. Therefore, it is very important to work out thorough counter measures for those problems, specially in high speed rail which high safety is required. The exact evaluation of longitudinal force of rail has the key to the solution. The main aim of the present paper is to examine whether the longitudinal force of CWR's on Kyung-Bu-HSR satisfy the criteria to be fulfilled in the design of railway bridge. The analyses are carried out by using "CWRAP" program which was developed by our research group. The ballast resistance and breaking force effects on the longitudinal force of CWR are investigated.

• International Journal of Precision Engineering and Manufacturing
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• v.3 no.3
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• pp.21-27
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• 2002

In this paper, a simple test rig of high-speed crash for the front members of vehicles was developed for the improvement of crashworthiness of vehicle's side rail. The cart hanging the specimen is accelerated up to 35 mph by the traction wire and by the force of freely dropping weight and 1:3 accelerating pulleys. The cart with shock absorbers travels on the rail roads, so it does not transfer any additional vibration to the specimen. In order to measure the energy absorbed by the specimen when it collapse to the wall and during it deform, the two strain gage type load cells are used at the wall place. The test rig rated good to test the specimen like a side rail of vehicle as developing the vehicle's structures in the early design stage.