• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.149-151
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• 2000

This paper compares the measurement values of harmonics to the analysis results in railroads testing system. Therefore, in this paper, new program to calculate THD(Total Harmonic Distortion) and measuring system of harmonics are developed. The harmonic measurement point is PCC(Point of Common Coupling), the primary side(154kV) of scott transformer, and the analysis is performed based on real KEPCO system data. As a result of this study, it is possible to present basic data and informations about harmonic problems which can be occurred in the future commercial railroad systems.

• Journal of the Korean Society for Precision Engineering
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• v.31 no.9
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• pp.773-776
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• 2014

KTX (Korea Train eXpress) is the first high-speed train operated in Korea and its highest speed reaches 300 km/h. Korean high-speed trains are mostly operated on the railroads exclusively designed for high-speed trains, but the sections of Seoul~Gwangmyeong, nearby of Daejeon station and Dongdaegu are operated on the existing tracks having the speed less than 150 km/h. With this paper, we'd like to analyze the lateral force that occurs between the wheels and the rail when high-speed trains were operated on the existing track section to suggest an appropriate driving speed for high-speed trains. As the rigid wheel base of the high-speed train is 3m which is about 50% longer than normal vehicles, it works as an advantage for high-speed driving. However, as the lateral force becomes higher than normal vehicles when driving on curves, plans to reduce wear-outs on the wheels are required.

• Journal of the Korean Society for Railway
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• v.8 no.2
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• pp.128-136
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• 2005

The reinforcing subgrade, which first introduced Korea for the highspeed subgrade construction, has the many advantages to maintain the quality of ballast track as well as to prevent the softening of subgrade by mud-pumping. It causes the subgrade soil to spout into the ballast on many lines. Therefore, the application of reinforcing subgrade will be expected to increase in the future. This paper introduces the reinforcing subgrade as a maintenance-free technology f3r the railroad operation and the method f3r the determination of reinforcing subgrade depth. The criteria on reinforcing subgrade depths of highspeed and conventional railroad were verified from the calculation results based on an elastic analysis method.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.211-219
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• 2005

The railway industry of each country has variant technical standards and regulations unlike other industries. For this reason, it is necessary to investigate the domestic technical standards and regulations and to prepare the countermeasure of the variance for advancing the korean high-speed railroad system into foreign market. This study was designed to investigate the railway design/manufacturing, examination/inspection and safety of domestic and foreign countries subject to a world market for advancing the korean high-speed railroad system into a foreign market. Because the reliance of a railroad system is a prerequisite for the safety of railroads, it is very important to obtain the reliance data, which is based on the RMS analysis of foreign countries subject to a world market.

• Journal of the Korean Society for Railway
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• v.5 no.4
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• pp.253-259
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• 2002

This paper presents the first simulation model using EMTDC program to analyze the electrified train voltage distribution characteristics in ac auto-transformer fed railroads. In general, all of the electrified train supply system has the characteristics that the train supply line is a naturally non-symmetrical and unbalanced system. Also, it is needed to model the Scott transformer which invert the balanced 3-phase quantity into 2-phase. Therefore, the general simulation methodology using previous simplified equivalent circuit or RMS based program can't obtain the accurate results to reflect the real-time operation because these methodology is basically assumed on completely 3-phase balanced system. To overcome these defects, in this paper, the EMTDC simulation model to analysis the completely electrified railroad system with Scott transformer and AC auto-transformer is presented. Also, the correctness of EMTDC modeling is confirmed by the old basic concepts and we think that this EMTDC model has the future powerful capability for application of railroad system analysis.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.115-118
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• 2007

The geometry of wheel and rail profiles is the primary contributor to wheel and rail interaction. These profiles interact to influence truck steering, vehicle lateral stability, wheel/rail wear and surface damage. Maintaining good control of the profiles is one of the keys to ensuring preferred wheel and rail interaction. Transportation Technology Center, Inc., Pueblo, Colorado, is developing an automated measurement system for wheel/rail contact condition inspections supported by AAR(Association of American Railroads). The system uses a modified version of $WRTOL^{TM}$ (Wheel/Rail Tolerances)--software that performs extensive analysis of wheel and rail contact conditions

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.514-522
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• 2007

Railway System has been developed by applying the advanced technology so that it reduces accident of hardware failure. But human error has been founded as important cause in railway accidents and safety. Medical condition is one of railway accident causes. Failure to recognize potentially incapacitating medical conditions can have serious safety consequences for railroad employees, the railroads and the public[1]. In order to find potential danger, we collect domestic/ foreign case for the medical examination and analyse characteristic/difference. The purpose of this study is to suggest information of employees' medical examination through comparing the current medical standard in railway industries.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.661-670
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• 2007

In this study, collision accident scenarios are derived for crashworthy design of rolling stocks because the detailed guidelines to complement domestic safety regulations with respect to collision accidents of rolling stocks are under preparation. Through this study, several collision accident scenarios are broadly investigated for those of advanced countries like USA, UK and EU. Next, the basic engineering considerations which are necessary to derive the collision accident scenarios are reviewed and analysed in some details. Finally, two collision accident scenarios are derived considering the circumstances of domestic railroads.

• Land and Housing Review
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• v.5 no.3
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• pp.169-177
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• 2014

Constructing urban public housing built adjacent railway site has the noise and vibration problem coming from operation of trains. Thus, anti-vibration plans utilizing anti-vibration pads must be established to minimize the impact of train noise and vibration from the tunnels on the residents of the public housing. Under various difficulties and expectation from the citizens, many efforts were taken to satisfy the amenity requirements on noise and vibration for the residential area. As a results, it can be recognized that amenity standards can be satisfied. But great caution is required to prepare ourselves for various situations that might occur during construction, especially considering that the relevant railroads are still under operation.

• Journal of information and communication convergence engineering
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• v.18 no.1
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• pp.28-32
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• 2020

Railway transportation is the main land-based transportation in most countries. Accordingly, railway-transportation safety has always been a key issue for many researchers. Railway pedestrian accidents are the main reasons of railway-transportation casualties. In this study, we conduct experiments to determine which of the latest convolutional neural network models and algorithms are appropriate to build pedestrian railroad accident prevention systems. When a drone cruises over a pre-specified path and altitude, the real-time status around the rail is recorded, following which the image information is transmitted back to the server in time. Subsequently, the images are analyzed to determine whether pedestrians are present around the railroads, and a speed-deceleration order is immediately sent to the train driver, resulting in a reduction of the instances of pedestrian railroad accidents. This is the first part of an envisioned drone-based intelligent security system. This system can effectively address the problem of insufficient manual police force.