• Proceedings of the Korea Concrete Institute Conference
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• 1998.10b
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• pp.894-899
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• 1998

To absorb the deformation of live load, thermal gradient, shrinkage and creep in bridge structures and general structures, expansion joint has to be established. Especially expansion joint for high-speed railway bridge has to accomodate the static and dynamic forces and it not only has the durability of itself but also maintain the durability of structure by preventing the leakage of water. The actual used product of expansion joint for high-speed railway bridge is only ones made in France, Germany and Japan. In this study, the development process and test results of developed expansion joint are introduced which has the functional operation and durability enough to apply to high-speed railway bridges, roadway bridges and general structures. The tests consist of fatigue-durability test of 3 million times by high-speed rail load, leakage test and jack-up test for verifying the possibility of exchanging it. The performance of developed expansion joint satisfy the specification of Korea High Speed Rail Construction authority.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1315-1317
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• 2003

In this paper, a hew ground speed signal detector used for railway vehicles is presented. A frequency 6-multiplier is designed to the proposed speed signal detector to achieve more precise ground speed from the slow analog signals made from mechanical tacho signal generator. The computer simulation is carried out to clarify its effectiveness.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1193-1194
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• 2007

2004년 경부고속철도가 개통된 이후, 열차제어시스템에 있어서 크고 작은 여러 가지 문제점이 시스템의 안정화를 위한 초기 단계의 형태로서 발생되었다. 특히 국내에서 처음으로 열차가 300km/h로 운행됨에 따라, 열차의 고속 운행 환경에 대한 운영 및 유지보수의 어려움이 자주 유발되었다. 한 예로 2005년에는 서울에서 약 170km 남쪽에 위치한 칠곡 신호기계실(IEC) 지역에 설치된 선로변 설비인 HBD의 오동작이 발생됨에 따라 관련 설비에 대한 신뢰성은 물론 설비의 기능상의 문제점까지 전면적인 검토를 필요로 하였다. 본 논문에서는 고속선 운영 및 유지보수에 있어서 선로변 설비의 장애 원인을 조사, 분석, 검토함으로서 고속선 열차제어시스템 HBD에 대한 안정적인 운영 및 유지보수를 구현하기 위한 방안 제시를 주요 목적으로 한다.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1565-1567
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• 2005

본 논문은 듀얼듀플렉스구조로 설계된 한국형고속철도 열차제어시스템의 전자연동장치 선로전환기제어모듈에 대하여 안전성활동 체계에 따라 위험원을 도출하고 분석하여 선로전환기제어모듈에 대한 위험측고장률을 예측하였다. 시스템으로 인해 발생할 수 있는 리스크를 분석하여 리스크를 완화하기 위한 안전대책의 수준인 안전무결성레벨에서 제시하는 정량적인 기준을 만족하기 위한 위험측고장률예측을 선로전환기 제어모듈을 대상으로 연구하였다.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.527-532
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• 2007

In this paper, we suggest those two design plans for power supply method of Hot Standby Sparing System; one is the plan using MTBF based on Constant Failure Rate, and the plan using Reliability Function is the other. Traditionally, RBD (Reliability Block Diagram) is used for reliability prediction which is required to meet any requirements before system operation. However, the system that has redundancy, such as Hot Standby Sparing System, Is not suitable for system reliability modeling using combination model, such as RBD. In this paper, therefore, we demonstrate that for redundancy controller, redundancy modeling design toward fault occurrence design is more effective to build up a system with higher reliability and achieve the effectiveness of loss cost due to maintenance and failure occurred in operation, rather than combinational modeling design.

• Journal of the Korean Society of Safety
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• v.38 no.2
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• pp.104-111
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• 2023

Rolling stock maintenance, which focuses on preventive maintenance, is typically implemented considering the potential harm that may be inflicted to passengers in the event of failure. The cost of preventive maintenance throughout the life cycle of a rolling stock is 60%-75% of the initial purchase cost. Therefore, ensuring stability and reducing maintenance costs are essential in terms of economy. In particular, private railroad operators must reduce government support budget by effectively utilizing railroad resources and reducing maintenance costs. Accordingly, this study analyzes the reliability characteristics of components using field data. Moreover, it resolves the problem of determining an economical replacement interval considering the timing of scrapping railroad vehicles. The procedure for determining the optimal replacement interval involves five steps. According to the decision model, the optimal replacement interval for the onboard signal device components of the "A" line train is calculated using field data, such as failure data, preventive maintenance cost, and failure maintenance cost. The field data analysis indicates that the mileage meter is 9 years, which is less than the designed durability of 15 years. Furthermore, a life cycle in which the phase signal has few failures is found to be the same as the actual durability of 15 years.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5534-5540
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• 2015

This In the railway signaling system, applications of axle counter in addition to track circuit goes on increasing for detecting train position. Consequently, this paper compares sensor methods of axle counter with between geo-magnetism method and proximity sensor method. And it presents differences and results, to improve reliabilities of train detection and axle counting. Also, this article presents an applied result which is based on field experience, with regard to installation, considering attachment condition of sensor part for accurate axle counting. This study acquires expandability that is able to perform not only axle counting function but also various other functions (direction detection of train, speed detection of train, and so on). It was a result of a change of design in order to judge phase difference of sensors, to improve reliability of axle counting. Furthermore, it does not subordinate to characteristics (type, weight of train). And it is confirmed that the omission of axle counting was not occurred in 350km/h. This was the result of Lab test after the construction of transfer equipment of trial axle and Test Bed for axle counting. Both of them are self-productions. Through this, it prepares foundation which is able to apply not only to train detection but also to speed of passing trains, formation number of trains, detector locking condition - when the train passes the section of switch point, and level crossing devices. Furthermore, it would be judged to contribute safety train operation if proximity sensor method applies to the whole railway signaling system from now on.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.6 s.52
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• pp.9-18
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• 2006

This paper presents schematically the monitoring system installed in Yongjong Bridge, a self-anchored suspension bridge located in the expressway linking Seoul and Incheon International Airport. Automatic measurement of instrumented civil engineering structures is now widely applied for behavior monitoring during construction in field as well as long-term monitoring for lifetime assessment of bridge structures. A representative example of results that can be acquired through structural health monitoring system is presented by means of data measured during a few years after the opening of the bridge. In order to effectively measure the tension force for hangers that have relatively short length or high tension force, a static tension measurement device has been explored. Newly equipped railway system on the existing bridge results in change of dead load, consequently dynamic characteristics have also been changed. This result can be detected by the monitoring system during and after railway construction.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.2
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• pp.71-79
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• 2008

High voltage distribution lines in the electric railway system placed according track with communication lines and signal equipments. Case of the over head lines is occurrence the many fault because lightning, rainstorm, damage from the sea wind and so on. According this fault caused protection device to wrong operation. One line ground fault that occurs most frequently in railway high voltage distribution lines and sort of faults is line short, three line ground breaking of a wire, and so on. For this reason we need precise maintenance for prevent of the faults. The most important is early detection and fast restoration in time of fault for a safety transit. In order to develop an advanced fault location device for 22.9[kV] distribution power network in electric railway system this paper deals with new fault locating algorithm using flow technique which enable to determine the location of the fault accurately. To demonstrate its superiorities, the case studies with the algorithm and the fault analysis using PSCAD/EMTDC (Power System Computer Aided Design/Electro Magnetic Transients DC Analysis Program) were carried out with the models of direct-grounded 22.9[kV] distribution network which is supposed to be the grounding method for electric railway system in Korea.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.576-581
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• 2007

The purpose of this study is to investigate changes in the forearm-muscle fatigue of a train driver operating the MasCon by using EMG (electromyogram) measurement technique. Train drivers usually use their forearm 4hours/day for normal operation. Accordingly, few different EMG signals of deltoid, biceps brachii, brachioradialis, flexor carpi ulnaris muscle of upper extremity have been measured and analyzed. The raw EMG Signals have been converted into median frequency using spectrum analysis. As the result, 80% of 10 subjects (real train drivers) showed that median frequency value of all four muscles has been reduced after 30 minutes of train operation. This results demonstrated that operating MasCon for 30 minutes could induce muscle fatigue.