• 한국정보과학회논문지:정보통신
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• 제34권1호
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• pp.73-80
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• 2007

본 논문은 인터넷 멀티미디어 응용을 위한 유력한 세션 제어 프로토콜인 SIP(Session Initiation Protocol)의 동적인 QoS(Quality of Service) 요구 사항을 광대역 접속망(Broadband Access Network)에서 지원하는 방안에 대해 논한다. 먼저 SIP QoS를 지원하기 위한 광대역 접속망의 구조와 동작 모델을 제시하고, 동적 QoS를 지원하는 SIP 시그널링을 IP QoS 메카니즘으로 변환하는 과정을 제시한다. IntServ 구조의 복잡성 문제를 고려하여 본 논문은 DiffServ 기반의 IP QoS 구조를 채택하고, 동적 SIP QoS에 대응되는 동적 DiffServ 지원을 위해 COPS(Common Open Policy Service)와 COPS-PR 프로토콜 기반의 시그널링 메카니즘을 제안한다. 또한 본 논문은 현재 급속히 확산되고 있는 메트로 이더넷(Metro Ethernet) 기반의 802.1 D/Q QoS를 지원하는 광대역 접속망을 가정하고, SIP QoS 매개변수를 DiffServ의 트래픽 등급으로 변환하는 방안, 그리고 DiffServ의 트래픽 등급을 802.1 D/Q 메트로 이더넷에서 지원하는 방안을 제시한다.

• 한국정보통신학회논문지
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• 제26권10호
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• pp.1447-1452
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• 2022

세계 10대 도시이며 Metro City인 서울특별시는 인쇄, 봉제, 기계금속 등 전통적인 도심제조업이 분포되어있다. 이들 제조업 집적지 내 소상공인은 서로 상부상조 하는 형태로 발전해왔다. 집적지의 특성상 각 공정은 개별 업체가 담당한다. 상대적으로 영세한 소상공인이 공정 간 실시간 물류 이동 정보를 제공하는 주문처리 서비스를 준비하기에 어려운 현실이다. 본 논문에서는 패키지(Package) 제조 및 특수인쇄 분야 소상공인의 원활한 수주, 배송 처리를 위해 기존 물류 Data를 수집, 분석하고 CRNN, k-NN, ID3 Decision Tree algorithm을 적용한 인공지능 Fulfillment Service Platform 시스템을 설계한다. 본 연구를 통하여 집적지 소상공인 누구나 Cloud 네트워크를 통하여, 개별 수주, 배송 맞춤서비스를 사용할 수 있게 함으로써 매출 증대 및 역량 향상에 크게 기여할 것으로 기대한다.

• 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.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 추계학술대회 논문집
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• pp.976-981
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• 2005

The Seoul subway line No.2 is the one of the busiest metro service line of the passenger transportation in Seoul metropolitan city. The number of the passengers served by the Seoul subway line No.2 is more than 1.9 million in a day according to the transportation reference of 2004, which is about $15\%$ of the whole population in Seoul metropolitan city. This is the reason why the Seoul Metropolitan Subway Corporation(SMSC) is implementing the refurbishment of the current ATS signalling system of Seoul Line No.2 into the most advanced ATO system with the continuous air-gap telegram transmission through the track circuit without any suspension of the train service either in when or in where, which is the first in the world in its attempt to refurbish the old signalling system under service without any suspension of the train operation.

• 한국철도학회논문집
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• 제15권5호
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• pp.508-516
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• 2012

전동차의 사용내구년한은 도시철도법에 의해 25년으로 되어있다. 그 사용제한에 의해 전동차 성능이 양호해도 사용연장을 위해서는 정밀안전진단을 받아야 한다. 사용내구연한의 연장은 내구년한 만료일의 다음 날부터 15년의 범위에서 정밀진단자가 인정하는 기간까지로 규정되어있다. 서울메트로 전동차의 일부가 25년간의 법정 사용내구년한을 채우고 1996년과 2008년에 신형전동차로 교체되었다. 교체된VVVF제어 신형전동차는 구형전동차에 비해서 안전성 유지보수성 내구성이 향상되어 그 성능에 알맞은 내구년한 설정이 필요하다. 본 논문에서는 LCC분석을 통하여 적정한 전동차의 경제적내구년한을 산출하였다. 25년부터 유지보수비용가중치 10%를 고려할 때에는 41년, 고려하지 않을 때에는 46년의 결과가 얻어졌다.

• 한국안전학회지
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• 제37권4호
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• pp.58-62
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• 2022

Metro subway construction is a field that requires a great deal of professional manpower. The aging of professionals has a negative impact on both productivity and health, owing to poor working environments, heavy lifting, underground work, and other factors. To address this issue, the government is progressively revising and enforcing health management law and regulation in the construction industry. Thus, the job stress and work ability of many professional subway construction workers, who are rapidly aging, are being analyzed to ensure their safety and improve their health. In this study, the Macpa stress index of Busan Metro Subway construction workers from Sasang to Hadan line was measured by using a Macpa measurement machine, and a work ability survey was conducted by using the questionnaire that was developed by the FIOH. The independent variables were age, years of service, job position, employment type, and occupation. While, the dependent variables were the Macpa stress index and work ability. The Kruskal-Wallis test was used because it was difficult to assume that the statistics of this study represented a normal distribution. The results showed that age, job position, and employment type affected Macpa stress index and revealed that as the age of the workers increased, their stress levels increased as well. Additionally, job position and employment type affected the work ability of the metro subway construction workers. In terms of job position, the technical engineers were under a lot of stress, and whereas the managers had the best work ability. The technical engineers were more stressed than the other workers because of a poor working environment. In terms of employment type, daily workers were under more stress and lower work ability than others.

• 전자통신동향분석
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• 제35권1호
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• pp.80-88
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• 2020

This paper describes the development trends and service provision examples of disaster occurrence and spread prediction technology for various disasters such as tsunamis, floods, and fires. In terms of fires, we introduce the WIFIRE system, which predicts the spread of large forest fires in the United States, and the Metro21: Smart Cities Institute project, which predicts the risk of building fires. This paper describes the development trends in tsunami prediction technology in the United States and Japan using artificial intelligence (AI) to predict the occurrence and size of tsunamis that cause great damage to coastal cities in Japan, Indonesia, and the United States. In addition, it introduces the NOAA big data platform built for natural disaster prediction, considering that the use of big data is very important for AI-based disaster prediction. In addition, Google's flood forecasting system, domestic and overseas earthquake early warning system development, and service delivery cases will be introduced.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.199-201
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• 2008

In this paper, We studied optimum service model of passenger car monitoring system at limited wireless bandwidth subway and railway. High bandwidth is better if we need more services. But, high bandwidth requires more cost at tunnel of subway. More bandwidth make receive sensitivity to bad. We deduced best bandwidth of subway wireless transmission system reflecting the cost of installation and efficiency of system. Consequently, we decide efficient service model of passenger car monitoring system.

• 통상정보연구
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• 제8권1호
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• pp.205-223
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• 2006

File sharing through P2P was decided as illegal according to Supreme Court of the U.S. and the Highest Court of Korea in 2005. Metro-Goldwyn-Mayer Studios Inc. et al. v. Grokster, LTD., et al. and Soribada v. Korea Association for Music Providers have the same ground for decision. P2P service company has vicarious liability for illegal file sharing of its customers. Balance between copyright protection and development of technology was considered in that decision. Programmer who will develop new program for free download and copyright holders who will exploit every measures to protect their right may compromise for their mutual benefits.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2011년도 제44차 하계학술발표논문집 19권2호
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• pp.409-412
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• 2011

본 논문에서는 LBS를 이용한 지하철 이용 서비스를 제안한다. 이 서비스는 지하철 내부에서 자신의 정확한 역 내 위치를 추적하고 공유할 수 있도록 하여 이용자의 편리성을 극대화 한다. 이 서비스는 GPS와 모바일통신 기술을 기반으로 하여 지상/지하 관계없이 사용자 자신의 위치를 추적함으로서 공간의 이동에 따른 서비스제약을 최소화 한다. 단순히 현재 위치를 실시간으로 제공하는 것을 목적으로 하는 것이 아니라 추출한 위치를 기반으로 목적지까지의 보다 정확한 도착시간, 잔여시간, 남은 정거장수, 알람시간 등의 정보를 제공하여 기존 서비스에서 더욱 고급화되고 향상된 서비스를 제공한다. 본 논문에서는 google map, naver map등의 open API를 이용하여 지도상에서만 제공하는 지하철 LBS보다 응용력 및 서비스 품질 면에서 우수함을 보인다.