• 디지털융복합연구
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• 제12권11호
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• pp.289-298
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• 2014

최근 들어, 보다 효율적이고 경제성을 갖춘 전기자동차 기술이 등장함에 따라 철도의 전통적인 기술적 패러다임이 변화하고 있다. 오래전에 제안되었지만 이상적인 개념으로 평가받던 수요응답형 순환교통(PRT) 시스템의 경우에도 전기자동차 플랫폼의 활용을 통해서 실현 가능성을 높여가고 있다. 특히, 배터리에 의해 구동되는 차량의 경우 안정적이고 효율적인 운영의 측면에서 기술적인 어려움에 직면하고 있다. 그렇지만, 무선 급전에 의한 급속충전 기술과 고에너지 밀도의 슈퍼커패시터 적용은 이러한 기술적인 난제를 극복하고 도시 미관의 향상을 통해서 전기 에너지를 기반으로 한 신교통수단의 보급을 증대하는데 기여할 것으로 생각된다. 본 논문에서는 한국형 PRT 차량의 전력공급 시스템의 설계, 에너지 소모량 및 장치의 성능 해석과 하드웨어 제작 및 시험에 이르는 일련의 개발과정에 대해서 논한다. 그 결과, 테스트베드에서의 전력공급 모듈의 시험평가 결과가 요구하는 성능에 부합하는 것으로 확인되었다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.487-491
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• 2007

Recently, rainfall induced hazard has been increased gradually, for example, typhoon Rusa in 2002 and Maemi in 2003. In addition, localized heavy rainfall has been also caused tremendous damage to railroad systems. Measured data from the Meteorological Adminstration sometimes, However, are not in accordance with those of rain gauges in local area, because of its good distance. This study develop automatic alarming software to estimate and prevent these kind of rainfall induced hazards in railroad system with online transportation.

• 대한전기학회논문지:전력기술부문A
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• 제50권8호
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• pp.359-364
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• 2001

This paper presents the influence of the lightning overvoltage and the shielding effect of lightning arresters and overhead grounding wires on the DC railroad systems. Modeling of railroad system is established in ATPDraw to perform the simulation and the line constants of railroad were calculated using ATP_LCC. When a direct lightning strikes to the DC railroad, the result of simulation reveals that the shielding effect of arresters is reduced at messenger, trolly-wire, and the shielding effects of overhead grounding wire is over 90% than the case which does not include it. Therefore it is evaluated that overhead grounding wires should be installed in the DC railroad line.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권12호
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• pp.4763-4775
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• 2020

This research aims to develop a deep learning-based method that automatically detects and segments the defects on railroad surfaces to reduce the cost of visual inspection of the railroad. We developed our segmentation model by modifying a fully convolutional network model [1], a well-known segmentation model used for machine learning, to detect and segment railroad surface defects. The data used in this research are images of the railroad surface with one or more defect regions. Railroad images were cropped to a suitable size, considering the long height and relatively narrow width of the images. They were also normalized based on the variance and mean of the data images. Using these images, the suggested model was trained to segment the defect regions. The proposed method showed promising results in the segmentation of defects. We consider that the proposed method can facilitate decision-making about railroad maintenance, and potentially be applied for other analyses.

• 한국정밀공학회지
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• 제34권3호
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• pp.205-210
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• 2017

Critical speed analysis was conducted for a active steering bogie prototype, developed to improve the curving performance of railway vehicles. The critical speed for the design concept was about 169.2k m/h. To validate the analysis result, we performed a critical speed test for the prototype bogie using a roller-rig tester. The test results showed that the critical speed for the prototype bogie was about 165 km/h. From the analysis and test results, The critical speed for the prototype bogie was determined to be 165 km/h. Considering the maximum operating speed of the test vehicle is 100 km/h, the prototype bogie is considered stable.

• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.252-255
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• 2014

In the case of long-stator linear drives, unlike rotative drives for which speed or position sensors are a single unit attached to the shaft, these sensors extend along the guideway. The position signal transmitted from maglev vehicle can't meet the need of the real-time propulsion control. In this paper the position estimator for propulsion inverter driving long stator linear synchronous motor (LSLSM) in high speed maglev train is proposed. In order to get the higher resolution of the position information transmitted from vehicle, Full order state observer is proposed for position estimator.

• 전기학회논문지
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• 제64권7호
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• pp.1125-1129
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• 2015

Increasing peak load is one of the major concerns about operation of urban railroad systems. Since ESSs (Energy Storage Systems) have a great potential for shaving the peak load, there has been a growing interest in the use of ESS for peak load reduction. Also, ESS can be optimally scheduled to minimize the electricity purchasing cost under a given ToU (Time-of-Use) tariff by taking advantage of electricity price difference between peak and off-peak time. This paper presents a Mixed Integer Programming (MIP)-based ESS scheduling method to minimize the electricity purchasing cost under a ToU tariff for an urban railroad system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.419-422
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• 2001

To safely control a group of trains, it is essential to detect the position of train. The system to detect the position of train by the train itself will become a mainstream of the new systems using radio transmission. This paper introduces the methods of train position detection that have been studied, introduces the trend of these methods. It also described the fundamental concept and approach to realize a system to detect the position of train which is applicable to systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2243-2245
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• 2002

This paper show Device Driver for RTOS-FT Systems. In this paper a definition of Device Driver is introduced which is used in RTOS-FT Systems. The structure of Device Driver is briefly divided into physical layer and logical layer. The specific characteristic of physical field and logical field which is discussed in this paper is suggested for the system which is satisfied with fault-tolerant theory.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.973-974
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• 2006

In this paper, Computer-aided Maintenance Equipments, which are being used in maintenance, are applied to analyze failures in train control systems, resulting in long time delays of trains. It can be expected to extend and apply CAMS (Computer Aided Maintenance System) in the hereafter efficient operation and maintenance of high-speed railway train control systems, by comparison between the analysis result of fundamental causes, from high-speed railway train control system failures occurred during the operational process, and predictive result of failure causes, based on the recording data of CAMS when failures were occurred.