• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권9호
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• pp.545-551
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• 2004

CBTC(Communication Based Train Control) System can improve train operation efficiency by realizing moving block system which makes a continuous train interval control in accordance with the position and speed of train. Adopting radio transmission to make a continuous detection of train position and transmit the control data from the ground to a train, CBTC needs dedicated train operation and control algorithm which should be quite different from the conventional track-circuit-based train control system. This paper provides a train operation display and control algorithm for CBTC system in making train interval control, train route control and train supervision. Signalling pattern diagram is devised to analyze the train interval control mechanism of moving block system, and interlocking logic is devised to represent the train route control mechanism of moving block system. For train supervision, train occupation status on railway are displayed by using the segment which virtually divide the whole railway. The proposed method has been successfully applied to the development of CBTC system for the standardized AGT(automatic guided transit) which is under construction now in Korea, and also can be applied to any other CBTC system.

• 한국철도학회논문집
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• 제18권2호
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• pp.105-110
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• 2015

본 논문은 RFID기술기반의 새로운 저비용 고정밀 열차위치검지기술을 위하여 빔폭 가변형 $4{\times}1$ 리더안테나 시스템의 설계를 제안하였다. 또한, 열차 구간별 속도 변화에 따라 제안된 리더안테나의 요구되는 빔폭 계산을 수행하였다. 열차속도에 의한 제안된 안테나 시스템은 사각패치형태의 방사소자들을 스위칭 커플러를 이용하여 임피던스 변환없이 두개의 모드로 동작하도록 설계되었다. 스위칭 커플러는 사각 quadrature coupler의 중심선에 Pin Diode를 그라운드와 연결하여 다이오드의 ON/OFF 설정으로 빔폭 가변을 스위칭 하도록 하였다. 설계된 안테나는 다이오드 OFF에 $18^{\circ}$와 다이오드 ON에 $39^{\circ}$의 빔폭을 확인 하였다. 본 논문에서 설계된 리더안테나 시스템은 향후 실제 차량 시험을 통하여 철도환경에서 보다 정밀한 열차위치검지기술 확보를 위하여 유용하게 사용될 예정이다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.671-679
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• 2011

Now, for the continuous location detection of train, The method which the moving distance and speed of vehicles are detected using an odometer mounted within railway vehicle, is used in railway domain generally. There are some problems that the train's positioning errors are accumulated as the moving distances increase. To solve this problems, The Train-borne Positioning System is being developed at Korea Railroad Research Institute. It is required to evaluate exactly a positioning performance of The Train-borne Positioning System for improvement of performance. Therefore, in this paper, we review the CDGPS methods to acquire reference position for performance evaluation of Train-borne Positioning System and verify the accuracy of the reference position through the static test and the vehicle test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.346-348
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• 1997

This paper presents microprocessor-based real-time speed and position detection by inductive radio loop in new transportation system, such as magnetically levitated train system, rubber tyred train, and linear-motor car. The constant elapsed time method is used in this study for high accurate detection over a wide speed range. And for reliability and safety of the system, it is duplicated and data-bus level comparison is performed by fail-safe comparator.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1729-1734
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• 2007

Recently, as the feasibility study shows that trans-Korea railway and trans-continental railway are advantageous, interest in high-speed railway system is increasing. Because railway vehicle is environment-friendly and safe compared with airplane and ship, its market-sharing increases gradually. We developed a measurement system for on-line test and evaluation of performances of KHST. The measurement system is composed of software part and hardware part. Perfect interface between multi-users is possible. Nowadays, position data inputs to pulse signal from wheel. Perfect position measurement was limited to slip and slide of vehicle. This measurement makes up for the weak points, Position Detection System using GPS develops. By using the system, Korean High Speed Train is capable of accurate fault position detection.

• 전기학회논문지
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• 제66권1호
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• pp.237-242
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• 2017

This paper presents development of the transponder system which provides an accurate train position, especially for supporting 400km/h high speed train. Here, we analyzed an operating frequency band of the transponder system which can be interoperable with the Eurobalise system already installed in Korea railroad as to be used for the automatic train protection (ATP). By investigating the power frequency band and its data frequency band of the transponder system, we presents the adoptable frequency band for the developed transponder system. Additionally, through the real testbed using HEMU-430X, we evaluate its performance requirement and shows interoperable operation with the Eurobalise system.

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5534-5540
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• 2015

철도 신호제어시스템에서 열차의 위치 및 점유 유무를 검지하기 위하여 궤도회로 이외에 axle counter적용 사례가 증가하고 있는 추세이다. 이에 본 연구에서는 열차검지 및 차축계수의 신뢰성을 높이기 위해 axle counter의 센서 방식을 지자기 센서 방식과 근접센서 방식을 비교하였으며, 그에 따른 차이점과 결과를 제시하였다. 또한, 정확한 차축검지를 위한 센서부의 취부조건 등을 고려한 설치에 대해 현장 경험을 기반으로 적용된 결과를 제시한다. 본 연구에서는 차축검지의 신뢰성 향상을 위해 센서의 위상차를 판단할 수 있도록 설계 변경한 결과 차축검지 기능뿐만 아니라 다양한 기능까지(열차의 방향검지, 열차속도검지 등) 수행할 수 있는 확장성을 확보하였다. 또한 열차의 종별, 무게 등의 특성에 종속되지 않았으며, 자체적으로 제작한 차축검지를 위한 모의차축 이송장치와 Test Bed를 구축하여 Lab. 테스트를 수행한 결과 350km/h의 속도에서도 차축 검지의 누락이 발생하지 않았음을 확인하였다. 이를 통해 열차의 검지뿐만 아니라 통과하는 열차의 속도와 편성 수, 선로전환기 통과 시 철사쇄정 조건 그리고 건널목 장치에도 적용할 수 있는 기반을 마련하였으며, 향후 철도 신호제어 시스템 전반에 확대 적용하게 되면 열차안전운행에 많은 기여를 할 것으로 판단된다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권10호
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• pp.3608-3626
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• 2021

The detection of bolts is an important task in high-speed train inspection systems, and it is frequently performed to ensure the safety of trains. The difficulty of the vision-based bolt inspection system lies in small sample defect detection, which makes the end-to-end network ineffective. In this paper, the problem is resolved in two stages, which includes the detection network and cascaded classification networks. For small bolt detection, all bolts including defective bolts and normal bolts are put together for conducting annotation training, a new loss function and a new boundingbox selection based on the smallest axis-aligned convex set are proposed. These allow YOLOv3 network to obtain the accurate position and bounding box of the various bolts. The average precision has been greatly improved on PASCAL VOC, MS COCO and actual data set. After that, the Siamese network is employed for estimating the status of the bolts. Using the convolutional Siamese network, we are able to get strong results on few-shot classification. Extensive experiments and comparisons on actual data set show that the system outperforms state-of-the-art algorithms in bolt inspection.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.69-74
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• 2011

In the curving detection method by using an accelerometer, the ride comfort in the first car is worse than one in the others due to spend the time to calculate the tilting command and drive the tilting mechanism after entering in the curve. In order to enhance the ride comfort in the first car, the preditive curve detection method which predicts the distance from a train to the starting point of curve by using the GPS, Tachometer, Ground balise and position DB for track. In this study, we predicted and evaluated the ride comfort for predictive curve detection method in transient curves according to the shape and dimension of transient curve and the various driving speed. Also, we predicted the improvement of the ride comfort for predictive curve detection method by comparing with the result of the ride comfort for predictive curve detection method and for curve detection method using an accelerometer in the short transient curve.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.638-640
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• 1996

This paper presents microprocessor-based Digital Position Detection Unit using the inductive radio line and the antennas in train signaling system. This comprises the Fail-Safe system due to the dual controlled system to drive with safe-side even in events of faults, and designs the FSC(failure safe comparator). And the method of Markov Modeling is described for the reliability evaluation of system.