• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.679-686
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• 2013

The reduction unit is one of the most important components in railway cars, due to the transmission of torque from the motor to the wheels. Faulty reduction gears in high-speed trains result from excessive wear on the gear or damage to the gear. These types of gear defects have a significant effect on high-speed rail operation and safety; thus, a diagnosis system for the reduction unit is needed. Vibration diagnosis technology is one of the most effective diagnostics. In this paper, the vibration parameters of a reduction unit were evaluated during a driving-gear test and a full-vehicle test, using kurtosis and the crest factor. These tests were performed under normal operating conditions; a specimen tester was used to diagnose problems in defective gears.

• Journal of the Korean Society for Railway
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• v.8 no.1
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• pp.63-81
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• 2005

In this Paper, Ⅰ illustrate the continuity and severance of Korean railroad. The Korean railroad has been running for 105 years now since it started operation in 1899. Between 1905 and 1945, Japan's imperial government ruled Korea including operations of the railroad. After Korea restored its sovereignty, Korean nationals managed the Korean railroad with our own ability and strategies. At present, we can examine the effect of railroad in perspective of continuity and severance respectively. For one thing, the concept of continuity is described as influence or railroad still remains. For another, the severance shows facts and phenomena that are broken off. I have come up with some facts that are involved with continuity. For example, infrastructure and the formation of cities and land spaces are connected with the sequence. Futhermore, the railroad has made a huge dent in modernization and expedition of movement. In the course of tracing down the facts, I classified the concept of severance : the separation of South and North Korea, drastic changes in transport policy, operations and characteristics. Finally technology has brought about a major breakthrough with the development of Koran high speed rail.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.10
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• pp.1051-1059
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• 2013

In general, lateral ride comfort of railway vehicle is mainly influenced by a secondary suspension placed between the bogie and carbody. Higher operating speeds of train results in increased vibration of carbody, which has a negative impact related to the ride comfort. To solve this problem, researches to replace the conventional passive suspension with (semi)active technology in the secondary suspension of a railway vehicle have been carried out. The semi-active suspension using the magneto-rheological damper is relatively simpler system and has advantage in maintenance compared to the hydraulic type semi-active damper. This study was performed to reduce lateral vibration acceleration of carbody related to ride comfort of railway vehicles with a semi-active suspension system. The numerical analysis was conducted by replacing passive lateral damper with semi-active MR damper, and robust control with the MR damper was applied to the 1/5 scaled railway vehicle model.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1754-1756
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• 2003

This paper describes the pantograph design result for tilting train at conventional railway. EMU(Electrical Multiple Unit) Tilting Train is important tilting pantograph. Tilting train pantograh should be operated to commercial service speed 180Km/h of 200Km/h at KNR upgrade railroad. This paper is written about train pantograph control system

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1689-1693
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• 2003

Communication based train control system is applied regularly worldwide. And this system may be used in domestic soon. Communication based train control system does not depend on conventional track circuit. Therefore, position and distance control of train to prevent collision with leading train may become important safety factor. This paper developed collision avoidance algorithm to control trains of several units efficiently for this. In developing a collision avoidance algorithm, it is desirable to avoid the need for additional system. Additional system restricts the development of the algorithm by limiting the effectiveness of the algorithm to only those areas where the additional system can be afforded and has been installed.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.175-177
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• 2008

The level crossing collision accident which comprises more than 90 percent of all level crossing accidents is one of the most serious safety problems. There is a critical need for providing safe strategy and is focusing on the level crossing information rather than measures at a grade crossing. This study is intended to develop technology for accident prevention and damage reduction based on accident cases analysis result and improvement direction to complement shortcomings of safety equipment of conventional level crossing and to establish safety of travelers(train, motor vehicle, person).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.11
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• pp.1913-1918
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• 2016

In order to analyze the power consumption pattern of the DC urban rail system, the method to obtain a solution establishing the current equation according to fixed position of the substation and varying position of the train is used. The proposed analysis method using the network analysis is to model the transfer function of the component constituting a direct current power supply system (dc substation, train, catenary) to the voltage and current. By multiplying the model formula consecutive, it can calculate the voltage and current of each element of power supply circuit and shows a simple case analysis.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2736-2739
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• 2002

This paper is a study on the railway traffic conflict resolution(RTCR) using genetic algorithm(GA). Using GA, many complicated problems can be expressed in the easy way, and good solutions can be found in a reasonably short time. Due to the above merits, we focus to GA first of all. We express the sample RTCR problem and algorithm of Korean railroad using GA. From the Mark Ho's[2,3] results, we introduce a chromosome scheme in addition.

• Proceedings of the KIEE Conference
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• 2003.11a
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• pp.205-209
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• 2003

Computerized simulation is becoming an indispensable procedure in the stage of planning, design, and operation of railway systems. This paper presents result of simulation technique for describing electrical performance of the power supply system which comprises the substation, catenary, feeder, and rails where multiple trains are running using result of train performance simulation.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.266-268
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• 2004

In this study, on-line measuring system were developed to verify performances and functions of traction system that are used in KTX(Korea Train eXpress) synthetically and efficiently, and have been measuring electric signals of vehicle as well as mechanical signals up to the present. Running-braking measuring equipment was constructed in vehicle to optimize signal acquisition and analysis ability of the measuring system. Measurement data of signal were performed acquisition, analysis and evaluation using this equipment. KRRI(Korea Railroad Research Institute) described about main specifications of measuring equipment. Also, the structure and principles as well as main circuit system were explained in brief. KRRI analyzed the characteristics comparing design values with experimental values about running distance, running time and positive acceleration for KTX is running in full traction. We analyzed the distance and time according to number of motor block. In result, running characteristics of traction system in KTX were verified and could be evaluated.