• Proceedings of the KIPE Conference
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• 2020.08a
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• pp.284-285
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• 2020

기존 국내 도시철도차량 추진시스템의 주변압기의 경우 권선형의 유입식 변압기가 사용되고 있다. 이러한 입력용 주변압기는 일반적으로 무게가 많이 나가며 전력밀도가 낮다. 또한 기존의 변압기의 경우 오일을 이용하여 절연을 하기 때문에, 정기적인 유지 보수에 따른 비용 발생 및 절연유의 오염에 따라 변압기 수명 단축 및 전력 품질 저하, 전력 손실증가, 전압 강하, 누유에 의한 환경 문제 등 여러 문제를 가지고 있다. 본 논문에서는 권선형 유입식 변압기를 대체하는 반도체 변압기 시스템 모델을 제안하였다.

• Journal of the Korean Society of Safety
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• v.25 no.1
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• pp.87-92
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• 2010

Urban transit system must secure fast, safe and reliable transportation capacity as a metropolitan mass transit. For this purpose, it is important to make all the sub-systems (which consist of EMU, power feeding, signaling & telecommunication, railway, platform facility, and control system and so on) work well. To operate all the systems effectively and reliably, a maintenance measure optimal to each system's characteristics is needed to be established and executed. So, highly reliable maintenance should be performed. But, EMU maintenance methods suitable to its own model and EMU lines are not yet introduced. This study examined few examples mainly to secure reliability on a maintenance quality in operating method and the features of train maintenance system based on travel distance.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.68 no.1
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• pp.199-206
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• 2019

Recently, an expansion of safety facilities has been widely applied to effectively manage the safety of train operation due to increase of the high-speed section of the general railway and the introduction of high-speed train. Accordingly, performance improvement, upgrading and high reliability of existing safety devices are required. the dragging detector, one of the safety devices, is an analogue system that consists of closed circuit with an electric current flows and operates when the closed circuit is opened by the impact of the dragging object. Such method has unreasonable problem that should be replaced after being detected. It is need to replace with an automatic return type dragging detector which is easy to maintain. In addition, it is necessary to develop a dragging detector that applicable to general railway and urban railway including high-speed railway, in accordance with the speeding up and densification of trains, although it is currently applied only to high-speed railway. In this paper, we propose an automatic return type dragging detector which has versatility and excellent maintainability with digital sensor and real time monitoring.

• Journal of the Korean Society for Railway
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• v.16 no.6
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• pp.447-453
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• 2013

Since PSDs(Platform Screen Doors) are set up at many subway stations, their design related to safety has become gradually important. In particular, the interference check with a running railway vehicle is the most important of performance indices because the collision between PSDs and vehicles can be dangerous for passengers in the car and on platforms. When the train comes into a station with a curvature, the passenger car has a large translational and rotational motion and the displacement is enough for coming in contact with PSD. The performance is affected by many design parameters such as rail design parameters and vehicle velocity. This study proposes dynamic analysis models for railway vehicles and rails. Some parameters were also considered in the models to determine their influence on the performance.

• Journal of the Korean Society of Safety
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• v.34 no.1
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• pp.76-81
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• 2019

In this study, the causes of human error were identified through the survey of the drivers of the three organizations: Seoul Metro, Seoul Metropolitan Rapid Transit Corporation, and Korail. It was started with the aim of finding and eliciting causes in various directions including human factors, job factors, and environmental factors. The Cronbach alpha value was 0.95 for the reliability significance of the stress-induced factors in the operational area. The significance probability for organisational factors was shown to be 0.82, and the significance of the sub-accident experience and the driving skill factors in operation was 0.81 In addition, the analysis results showed that stress-induced in the field of driving is higher than the human factors in the reliability analysis. The results of the analysis confirmed that the reliability of the organizational and operational stress-induced factors was higher than other causes. In order to reduce urban railroad accidents, this paper suggests a method for operating safe urban railroad through the minimization human errors.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.38-46
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• 2011

Recently railway operators are doing a lot of researches and studies in order to apply reliability technologies to their maintenance tasks. The maintenance in the aviation and the munitions industry has been developed enough to be benchmarked with the high quality reliability technologies; however, railway industry is still situated in a rudimentary stage with insufficient & limited data. 5678 Seoul Metropolitan Rapid Transit Corporation, which has 17 year experience of the EMU maintenance and system development, has made a constant effort for appling RCM (Reliability Centered Maintenance) to the maintenance for a few years. In this connection, the case study is to be introduced. This paper is based on 'RCM Gateway to World Class Maintenance' by Anthony M. Smith". The reliability technology are applied to the specific EMU and its system by 7 stages; accordingly, applying SMRT's maintenance experience, a unique standard for FMEA(failure mode effect analysis) & LTA(logical tree analysis) is established. Moreover, for reasonable and effective preventive maintenance tasks, the case considering an analysis of failure effects is selected in the final step 7. SMRT will develop reliability technologies through the application of the results to all the EMU systems.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.12-17
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• 2020

This paper analyzes functions of component parts of D-Urban Railway's door system along with operation obstacle risks on frequency(the number of occurrences/year) and severity(delay time/the number of occurrences). Based on this, the paper presents improvements and current system's problems after obstacle risks of EMU and door system are appled. The obstacle of door system causes corrosion of main parts such as DCU due to heat problem of operation environment, problems of maintenance methods and deterioration. DCUs on PCBs with more than 50% pattern corrosion cause problems. Even though the number of door system's obstacle occurrences for the last 5 years is 42, along with 104 minutes of operation obstacle, EMU operation obstacle risk is low(Level 1), which indicates there is limit in matrix of railway risks presented by the standard of railway safety management system. Therefore, it is necessary to have railway risk matrix suitable for the field. Finally, the paper deducts the obstacle risks through frequency and severity. Since 2017 when the risks of EMU and door system's obstacle, that of EMU has been 24(47% reduced) and that of door system has been average 9.5 per year(23% reduced).

• Journal of the Korean Society of Safety
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• v.28 no.2
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• pp.6-13
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• 2013

This study focuses on finding ECO driving patterns which consider driving safety of the ATO system train and reliability and which optimize efficiency of the driving energy consumption. Research results derived by performing simulation of those 5 models show that the emergency braking which affects safety of passenger and the machinery is minimized, and safe driving speed is maintained by the prohibition of drastic acceleration/deceleration, coasting and constant-speed driving. Therefore if this result is applied to the urban railway train by amending or making ATO program to save energy usage that improve environmental quality, its effects as ECO driving pattern is huge.

• Journal of Korean Society of Transportation
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• v.34 no.5
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• pp.465-475
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• 2016

Since inaccurate demand estimation for recent urban rail construction may result in financial burden to cities, precise prediction for operating cost as well as construction costs is necessary to avoid or reduce budget loss of the local or central government. The operating cost is directly related to the public fare and affect a policy to determine the rate system. Therefore, there is a pressing need to develop an estimating model for reliable operating cost of urban railway. This study introduces a new model to estimate the operating cost with new variables. It provides a better prediction in accuracy and reliability compared to the existing model, considering the feature of urban railway. For verification of our model, railway operation data from a few cities for the last five years were comprehensively examined to determine variables that affect the operating cost. The operating cost was estimated in a dummy regression model using five independent variables, which were average distance between stations, daily trains distance, total passenger capacity of a train in a train, driving mode(manned/unmanned), and investment type(financial/private).

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.626-631
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• 2007

With its critical pending task of putting the management into the right track, it is extremely important for the Korea Railroad Corporation to incorporate more reasonable distribution into train consists to cut down its operation costs and attain higher income surplus in the Metropolitan Train Business. Furthermore, for Jung-ang Line soon to be operated without any crew on-board, more adequate train formation looks very indispensable mainly to satisfy transportation demands as well as enhance the passenger safety. This paper will examine the Jung-ang Line with hourly-basis congestions and inter station O/Ds to get the better operation schedules and trainset numbers.