• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.687-693
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• 2013

The service conditions of railway cars have become more difficult in recent years due to increased speed. Faulty components in the railcars may result in service interruption, or in extreme cases, derailment. Thus, it is important to diagnose and monitor the main components of railcars. Temperature monitoring is one of the basic methods used to diagnose abnormal conditions in the main components of railway cars, such as in bearings, reduction gears, and traction motors. In this study, we developed a monitoring system for the main components, using an infrared thermography technique. This technique has the advantage of infrared thermal camera imaging of temperature contours in the components. Various hardware and software components of the monitoring system are used to acquire the sensor data, to identify potential problems in railcar operation.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.53 no.1
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• pp.32-39
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• 2004

Railway signaling systems consist of several vital computerized equipment such as CTC(Centralized Traffic Control), EIS(Electronic Interlocking System), ATC(Automatic Train Control) and so on. Currently, the project for development of railway signaling systems for the next-generation high-speed train is progressed according to the G7 project and railway signaling related several companies and research institute are joined this project consortium. The railway signaling systems, being developed in this project, called as a kTCS(Korean Train Control System), is composed of kTCS-CTC, kTCS-IXL, kTCS-ATC and etc. kTCS signaling systems have to be operated at the laboratory testing level as integrated signaling systems by interface between each railway signaling systems before railway field installation and revenue service. To solve this matter, communication protocols between each signaling equipment are designed and message codes for each defined protocols have defined. And also several equipment has developed for the railway integrated signaling systems for laboratory testing. We has plentifully tested and verified the designed protocols and the characteristics of integrated railway signaling systems with our developed each kTCS signaling equipment and communication protocols. In this paper, the integrated kTCS system including communication protocols is presented.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.862-867
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• 2008

High-speed railway is important transportation in the world because it is very comfortable, environmental benefits, energy savings, etc. The increase of demand for high-speed railway influence to develop of new hish-speed trains. Many countries introduced new high-speed train in the market. It meets to the market's needs. They adopt new technology and systems like that active suspension, synchronous permanent magnetic motor, distributed drive system, aero acoustics, etc. In Korea, the project for R&D of new high-speed train is launched last year. We need analysis of technical trend of new high-speed trains in the world. This paper presents a overview of technical trend of new high speed trains and what is key issues in development of high-speed train. It is very useful to develop a next generation high-speed train in Korea.

• International Journal of Railway
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• v.6 no.2
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• pp.64-68
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• 2013

In recent years, the speed of a train has been recognized as one of the important factors to determine the competitiveness as a mean of transportation. In line with this, infrastructure improvements and enhancements are being made with increases in the speed of train. Accordingly, there is a need to establish plans for infrastructure improvements through a comprehensive analysis of signals, track/civil engineering, catenary and environment, etc. to improve the speed of a train of high-speed train service sections in Korea. This study proposes improvement plans for catenary systems by investigating the possibility of improvements through performance analysis of catenary equipment by speed increase based on the analysis on catenary systems in Gyeongbu high-speed line, and analysis the applicability of catenary improvements and economic feasibility.

• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.203-211
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• 2015

Ride comfort of a vehicle can be utilized to maintain the track geometry and track irregularities because ride comfort of the rolling stock is affected by the characteristics of the vehicle and track. Ride comfort was evaluated according to the measured floor acceleration data of vehicles for a Korean high speed line as well as European high speed lines using Continuous comfort method which can be applied to track maintenance. The exceedance distribution of the ride comfort was quantitatively analyzed by the vehicle speed, the ride comfort of the Korean high speed line was compared with that of European high speed lines. It is shown that the ride comfort of Korean high speed line is better than that of European high speed lines, which indicates that the Korean track geometry and track irregularities are properly maintained.

• Smart Structures and Systems
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• v.26 no.5
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• pp.591-603
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• 2020

Dynamic deflection monitoring is an essential and critical part of structural health monitoring for high-speed railway bridges. Two critical problems need to be addressed when using inclinometer sensors for such applications. These include constructing a general representation model of inclination-deflection and addressing the ill-posed inverse problem to obtain the accurate dynamic deflection. This paper provides a dynamic deflection monitoring method with the placement of optimal inclinometer sensors for high-speed railway bridges. The deflection shapes are reconstructed using the inclination-deflection transformation model based on the differential relationship between the inclination and displacement mode shape matrix. The proposed optimal sensor configuration can be used to select inclination-deflection transformation models that meet the required accuracy and stability from all possible sensor locations. In this study, the condition number and information entropy are employed to measure the ill-condition of the selected mode shape matrix and evaluate the prediction performance of different sensor configurations. The particle swarm optimization algorithm, genetic algorithm, and artificial fish swarm algorithm are used to optimize the sensor position placement. Numerical simulation and experimental validation results of a 5-span high-speed railway bridge show that the reconstructed deflection shapes agree well with those of the real bridge.

• Journal of the Korean Society for Railway
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• v.2 no.3
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• pp.5-7
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• 1999

Ten years have passed since my last visit to Korea on the occasion of the International Symposium on High Speed Rail Systems organized by the Korean Transport Institute in October 1989. At that time, it was the objective to introduce the maglev and VHSR (very high speed rail) systems with their different areas of application and to discuss them with local partners against the background of the Seoul-Pusan HSR project. Congratulations on the success of the Centennial seminar. I am much pleased to be invited to the memorable seminar and I would like to express my sincere gratitude to Korean members' hospitality. (omitted)

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.4061-4076
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• 2017

With the development of high-speed railway technologies, train velocities can now reach speeds up to 350 km/h, and higher in the future. In high-speed railway systems (HSRs), loss of communication can result in serious accidents, especially when the train is controlled through wireless communications. For to this reason, operators of Long Term Evolution for Railway (LTE-R) communication systems install eNodeBs (eNBs) with high density to achieve highly reliable communications. However, densely located eNBs can result in unnecessary frequent handovers (HOs) resulting in instability because, during every HO process, there is a period of time in which the communication link is disconnected. To solve this problem, in this paper, an HO scheme based on the maximum cell residence time (CRT) and adaptive time to trigger (aTTT), which are collectively called CaT, is proposed to reduce unnecessary HOs (using CRT estimations) and decrease HO failures by improving the handover command transmission point (HCTP) in LTE-R HSR communications.

• Journal of the Korean Society for Railway
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• v.18 no.2
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• pp.117-126
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• 2015

The development of railway roadbed for 600km/h train speed level is very difficult because unpredictable static and dynamic interaction occurs between the ultra-high speed train and the infrastructure. Especially, an earthwork-bridge transition zone is a section in which influential factors react, such as bearing capacity, compression, settlement, drainage, and track irregularity; these interactions can include complicated dynamic interaction. Therefore, if static and dynamic stability are secured in transition zones, it is possible to develop roadbeds for ultra-high speed railways. In the present paper, design parameters for transition reinforcement applied to present railway design criteria are analytically examined for ultra-high speed usage on a preferential basis. Design parameters are the presence of reinforcing materials, geometric shape, stiffness of materials, and so on. Analysis is focused on the deformation response of the track and running stability at ultra-high speed.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1396-1406
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• 2008

The Directional sign system in Korean high speed railway stations has a lot of problems. For an example, It lacks of consistency in the shape or allocation. Also, the signs do not match with the actual directions sometimes. Last but not least, the view is blocked by the other signs such as advertisement or other barriers. We suggested the methods to standardize the sign systems that include visibility, accuracy, consistency, and simplicity. First, we categorized signs into directional signs, locational signs, and informational signs. Then, we examined the actual high speed railway stations in Korea to learn the real situation. Finally, we suggested the methods to standardize the sign systems considering the factors that are visibility, accuracy, consistency, and simplicity.