• 대한전자공학회논문지TC
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• 제38권4호
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• pp.18-26
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• 2001

본 논문에서는 극성 판단(Polarity Decision) PD를 이용하여 모드 변환과 루프이득(Loop Gain)의 변환시점을 자동적으로 검출해 주는 ATC(Automatic Transfer mode Control)알고리즘을 설계하고 모드 전환시 안정적으로 주파수 오프셋을 추정하는 평균방식 Gear-shift PLL을 설계하였다. 제안하는 모드 전환 시점 검출 알고리즘인 ATC 알고리즘은 종전의 QPSK방식에 적용되던 Lock Detector 알고리즘보다 구현이 매우 간단하며 정확하게 모드 전환시점을 검출한다. 또한 Shift Register에 저장했던 주파수 추정 값들을 평균하는 평균전환방식은 모드 전환시 낮은 주파수 추정 에러값으로 다음 모드에서의 빠른 추적 성능을 가능하게 한다. 본 논문에서 제안하는 알고리즘은 적은 회로 면적과 고속 처리가 가능하도록 설계되어 ASIC 설계에 매우 유용하다. 아울러 본 논문에서는 극성판단 PD를 적용하여 위상 포착 및 추적 성능평가를 수행하고 성좌도(constellation)를 각 모드별로 분석하였다.

• 전기학회논문지
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• 제58권6호
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• pp.1116-1122
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• 2009

ATS(Automatic Train Stop) system makes train stop when it runs over the speed limit and ensure the safe operation of train. Seoul Metro line 2 in Korea, which started its passenger service in 1982, has adopted ATS system for its signaling system. The ATS system has only a train stop function at the time of emergency, and Seoul Metro is planning to replaced them with ATC(Automatic Train Control)/ATO(Automatic Train Operation) system which can provide the dedicated speed control for headway reduction and automatic operation of train. Until all the ATS system is replaced with the new ATC system, both systems are to operate simultaneously at the same metro line. In this situation, ATS system sometimes reveals improper operation: train stops suddenly without any obstacles in front of it. These emergency stops cause interruption of passenger service, and abnormal abrasion of wheels and rail. This paper makes it clear that these interruptions are caused by EMI phenomena between ATS on-board device and ATC wayside device : Signal current flowing in AF track circuit of ATC is turn out to be a EMI source that prevent normal operation of the ATS on-board device. Although the two systems have different frequency-ranges (ATS system has frequency range between $78{\sim}130$[kHz] and ATC system has frequency range between $9.5{\sim}16.5$[kHz]), it turned out that EMI phenomena appears between the both systems. This is investigated by measuring the output signal from ATS on-board device passing over ATC wayside device. The FFT(Fast Fourier Transform) analysis of the signal reveals that AF track circuit signal is transmitted to the ATS on-board device and induce noise causing improper operation. The countermeasures to the EMI phenomena are examined in three ways; blocking EMI transmission, enforcement of EMS (Electromagnetic Susceptibility) of ATS on-board device, and blocking the EMI source. It is suggested that the practical solution be blocking EMI source temporarily, that is breaking AF track circuit signal when the trains with ATS on-board device pass over it. To this purpose, TODS(Train Occupation Detection System) is developed, and has made a success in preventing the EMI problem of Seoul Metro line 2.

• 전기학회논문지
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• 제67권1호
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• pp.61-67
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• 2018

Automatic Train Stop (ATS) is a device that automatically stops or decelerates a train when the train exceeds the permitted speed limits or violates the signal regulations. The railway signaling system has been evolved to an automatic train control system (ATC), and is being developed into Distance-to-Go and Communication Based on Train Control (CBTC). In spite of that, the ATS system is currently being operated in Seoul Metro (line 1 and 2) and most of railway lines in Korea as well as overseas. In this study, we presents the technical methodology to prevent human errors in order to secure the safety in operation of the ATS system.

• 한국항행학회논문지
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• 제18권4호
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• pp.268-277
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• 2014

비행계획 연관은 안전하고 신속한 관제 업무를 위해 매우 중요한 기능이다. 본 논문에서는 레이더 감시자료 중 MRT 데이터와 비행계획을 연관시키는 과정에서 발생하는 네트워크 부하를 최소화함으로써 전체적인 항공교통 자동화 시스템의 성능을 향상을 도모할 수 있는 CWP MRT 처리 모듈을 구현하였다. 구현 모듈은 분산형 연관 방식을 적용함으로써 항공교통관제 자동화 시스템의 효율성과 안전성을 동시에 확보하며, 인코딩 방식의 비행계획 연관 MRT 데이터 포맷을 사용함으로써 네트워크 사용률을 감소시킨다. 구현 모듈은 독립형 연관 방식에 비해 네트워크 사용량이 8.54~12.11% 낮았으며, 네트워크 공정성이 8.37~11.27% 높은 것을 확인하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1995년도 VTS and IBS 95 The Korean Institute of Navigation 1995년도
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• pp.11-14
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• 1995

The question of recruitment qualification and standardization of VTS operators is reviewed through comparison with Air Traffic Control(ATC) The comparison reveals greater difference between the two services than commonality. While ATC enjoys a high degree of uniformity nationally and internationally the provision of VIS is dictated by varying local needs. The variety of those needs makes standardization of VTS operation a questionable short term objective. The paper concludes problem solving techniques such as the formal appreciation provide means of matching recruitment and qualification to local requriements.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.755-764
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• 2008

When the high speed train (KTX) departs from station in the high-speed line, sometimes on board signal disappears, which causes a hindrance of the operation punctuality, therefore, we have a research objective to verify the causes of hindrance and to find an improvement plan. In the process of research, when train left, we applied sand on the rail to improve adhesive power, whose sand has an effect on the ATC(Automatic Train Control) signal wave. We detected & analyzed signal waves which came from detecting device by changing operation condition in accordance with sand material

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1461-1466
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• 2004

Recently Domestic EMU's on board signal systems are gradually changed form Cab signal(Fix Block) to Distance-to-go. Interfaces with on board signal system, TCMS Redundancy structure is mainly required. This paper suggest Manaul/Automatic Driving based on TCMS-ATC interface and design of backup system which is operated by Stan-by Computer when one of it's Local Interface Unit(LIU) is out of oder. For the purpose of Precision Train Stop, Distance-to-go signal system require accuracy speed. Free-axle structure is required for this system This paper suggest Free-axle braking system that lack of brake-force is compensated by the distributed brake-force using TCMS. And one of braking system has out of order, compensation of brake-force for Free-axle system. Then we prove our design to Complete Car Test

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.906-911
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• 2006

Since railway system has been developed, the interface system which is interfaced with various sub-systems of railway including rolling stock, SIG, COM, catenary system came out more complicated and mixed-up. For the purpose of improving the management techniques about interface system among the sub-systems of railway, this paper proposes method of management by using of SE(system engineering) that makes structure of data system through describing and separating the user's requirements, functional analysis and interface of the train control system in its degree. This study is focused on the ATC signaling sub-system, a important part of SE, to analysis of the system.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.211-225
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• 2011

Railroad signalling systems are to control intervals and routes of trains. There are ATS(Automatic Train Stop), ATP(Automatic Train Protection), ATO(Automatic Train Operation) and ATC(Automatic Train Control) system. Trains are operated in the section which is met on the signalling system because various signalling systems are used in Korea. On the other words, trains are not operated in the section which is used in the other signalling system. To solve this problem, recently combined on-board system has been developed. The combined on-board system is designed by doubling the ATS, ATP and ATC system. Information signal is received by magnetic sensors in the ATC system and is received by antennas in the ATS and ATP system. Therefore, it is possible to arise transmission problems by magnetic coupling. In this paper, electric model of the ATS and ATP antenna is suggested and interference frequency by the magnetic coupling between the ATS and ATP antenna is estimated numerically. As a results of the magnetic coupling, the value of the magnetic coupling is presented without magnetic induction.

• 대한전자공학회논문지SD
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• 제40권12호
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• pp.24-30
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• 2003

본 논문에서는 첨두 검출기의 구조를 개선함으로써 정착시간(settling time)을 더욱 단축시킬 수 있는 적응형 기준레벨자동 발생회로를 제안했다. 제안한 기준레벨 자동 발생회로에 대해 비슷한 정착시간을 설정하였을 때에 오차전압비율이 기존 구조에 비해 절반 이하로 줄일 수 있어 정착시간을 상당량 개선할 수 있음을 해석을 통해 밝혔다. 아울러 상용 파운드리(foundry)를 이용하여 1.25G EPON 시스템용 버스트 모드기준레벨 자동 발생회로를 설계한 결과 동적 영역(dynamic range)이 40㏈인 입력신호에 대해 6㎱ 라는 매우 짧은 시간 이내에 기준 레벨을 생성해 내는 결과를 얻을 수 있었다.