• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2755-2761
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• 2011

The purpose of this study was to analyze and improve the communication interferences in the wireless communication equipments of the CBTC applied to a model intelligence train control system. So far, train positions have been traced by the conventional fixed blocking system to control the operation of the trains, but the new CBTC system uses the on-ground location to transmit the train positions wirelessly to the ground control center continuously, so being more vulnerable to communication interferences. Although the researcher analyzed and improved such interferences in the communication equipments of the CBTC system, there remain more rooms for its improvement.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1158-1161
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• 2004

This paper describes the construction of a half sphere screen driving tilting simulator that can perform six degree-of-freedom (DOF) motions simulator to a tilting train. The mathematical equations of Tilting Train dynamics are first derived from the 6-DOF bicycle model and incorporated with the bogie, carbody, and suspension subsystems. The equations of motion are then programmed by visual C++ code. To achieve the simulator functions, a motion platform that is constructed by six electric-driven actuators is designed, and its kinetics/inverse kinetics analysis is also conducted. Driver operation signals such as carbady angle, accelerator, and tilting positions are measured to trigger the Tilting dynamics calculation and further actuate the cylinders by the motion platform control program. In addition, a digital PID controller is added to achieve the stable and accurate displacements of the motion platform. The experiments prove that the designed simulator is adequate in performing some special rail road driving situations discussed in this paper.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.139-145
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• 2001

The purpose of present study is to find design parameters and operating conditions of the HVAC system in a subway platform. The simulation was carried out for the flow, heat and mass transfer for heating, ventilating and air-conditioning(HVAC) environments in the subway platform. The steady-state. incompressible flow assumption and standard $k-{\varepsilon}$ turbulence model are adopted. The location of HVAC air inlet above platform and the volume flow rate of curtain air released from inlet B are chosen as main parameters in this study. The results of present study are following: In the case of existence of train, the heat and contaminant released under the train have no effect on the average temperature and mass fraction of contaminant in the platform, but heat released on the train has influence on the average temperature in the platform. Train acts as an obstacle to exhaust the contaminant in the platform, but has good effect on the average temperature in the platform.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.3
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• pp.78-87
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• 1998

A dynamic model of direct-acting OHC valve train system has been used to determine the load conditions in the system. The modified equations for calculating the friction forces between cam and HLA, and at a camshaft bearing have been defined considering the lubrication conditions. Then, to understand the frictional characteristics in the system, a parameter study has been performed. As the results of the analysis, valve spring stiffness and preload have great effects on the friction in the system, but the effects of other parameters are negligible. So, how to design the valve train system with respect to the reduction of friction is to minimize the valve spring stiffness and preload in the limit of satisfying the dynamic constraints.

• Journal of the Korean Society for Railway
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• v.2 no.1
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• pp.16-27
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• 1999

The purpose of this study is to suggest the effective analytical procedure using finite element model for the crashworthiness of motorized trailer of high speed train. The static crush of rectangular section frame is analyzed by experiment and numerical simulation. The equivalent thickness distribution of the aluminum frame ensuring the same energy absorption as the steel frame is obtained. In the analysis of end-on collision of TGV-K, deformed pattern and section forces are obtained, and the effect of crushable zone are examined. The numerical results are applied to the design of motorized trailer of Korean high speed train.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.3-5
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• 2004

In order to speed up basic concept is to enhance high speed, curve limit speed, cross limit speed, acceleration/deceleration speed. It is important to optimal interface fundamental technology of vehicle, rail, electrical power, and signal system. Tilting train has advantage minimizing investment cost of infra railway system for increasing train limit speed in curve. the developed tilting train should be operated to commercial service speed 180Km/h of 200Km/h at KNR upgrade railroad. This paper proposed the basic model of system engineering for developing of TTX, tilting EMU (maximum operation speed : 180km/h) with speed-up of conventional railway system.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.10a
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• pp.220-223
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• 2004

The weight reduction of carbody structures is of great concern in developing high speed tilting train for the normal operation of tilting system. The use of composite materials for the carbody structures has many advantages due to their excellent material properties. In this paper, finite element analysis was conducted to analysis and design the composite structure of Tilting Train eXpress(TTX). According to JIS E 7105, static load tests were performed and the structural safety of the composite carbody structure was verified by conducting finite element analysis of the model to which reinforcing frame are added in the composite carbody structure. In addition, modal analysis was conducted to estimate the natural frequency of a train.

• Journal of the Korean Society for Railway
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• v.8 no.3
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• pp.228-234
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• 2005

Investigation on the dynamic behavior of railway bridges has not performed widely to date except high-speed railway bridges. In this study, 3-dimensional model is used for the finite element analysis of plate girder railway bridges. Train loads obtained through statistical approach of the measured true train loads are used. Numerical analysis is carried out about a 18m-span bridge. This result is compared with that of the experimental test of existing plate gilder railway bridge without ballast. The good agreement was obtained through the comparison. Judging from the analysis, resonant speed of diesel locomotive train is about 120km/h. However, the resonance for the other train is not found from the analysis.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.198-204
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• 2001

Train crashes involve complex interaction between deformable bodies in multiple collisions. The purpose of this study is to suggest the effective analytical procedure using hybrid model for the crashworthiness of motorized trailer of high speed train. The hybrid approach, with very short modeling times and reduced computation times to extract the global behaviour and to perform a pre-optimization of the considered structure. Firstly, various types of crash events are investigated and the conditions for numerical simulation are defined. In this paper, the structural crashwonhiness of Korean High Speed Train trailer was examined through FE analysis. Crash analyses on energy absorbing part and safety zone were carried out to determine each section force. Rollover analysis was performed to observe the amount of intrusion in the passenger's area in case of rollover accident.

• Journal of the Korean Society for Railway
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• v.9 no.5 s.36
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• pp.511-516
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• 2006

A standard framework of CFD(Computational Fluid dynamics) analysis for railway system has been developed to evaluate the overall aerodynamic performance of railway system and has been adopted to numerical simulation of the pressure field around KTX train. The framework is composed of standard aerodynamic model and standard aerodynamic performance to customize the general CFD solution process reflecting the characteristics of railway system such as various operation mode and performance factors. The results show that the standard framework of CFD analysis for railway system can provide objectivity and consistency to the CFD analysis for railway system and the pressure field around KTX train has been successively solved.