• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2292-2299
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• 2011

The CBTC(Communication Based Train Control) system, a recent train control system, is a wireless communication based train control system that is operated in the moving block system control by tracking trains in real time. In additioin, the system helps to increase the volume of traffic by shortening driving headways through controlling moving block system control. Furthermore, driverless modes are performed by controlling ATP(Automatic Train Protection)/ATO(Automatic Train Operation). In this paper, controllable elements in ATO driverless train control system, affecting comfortable ride, will be analysed and applied to CBTC train control system that developed by POSCO ICT. Finally, the test results of improved comfortable ride will be showed by appling the developed system to the Gyeong-san light rail transit test track.

• 한국통신학회논문지
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• 제19권2호
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• pp.306-321
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• 1994

각 노드에게 타임슬롯을 정적으로 할당하는 TDM 프로토콜은 동작이 간단하고 고부하에서의 처리율이 높다는 잇점 때문에 TDM 프로토콜을 다중채널 고속통신망에 적용하는 연구가 활발히 이루어지고 있다. 그러나, 다중채널 TDM 프로토콜에서 저부하에서의 지연시간이 필요이상 크고 트래틱의 편중화에 동적으로 적응하지 못하는 것은 해결되어야 할 문제점이다. 본 논문에서는 이러한 문제점을 완화할 수 있는 새로운 TDM 프레임 구조를 제안한다. 제안된 구조에서 상호 트래픽이 많은 노드를 사이에는 많은 양의 타임슬롯이 할당되며 그렇지 않은 노드들 사이에는 상대적으로 적은 양의 타임슬롯이 할당됨으로써 지연시간과 처리율이 개선된다. TDM 프레임 설계시 고려해야 할 사항을 처리율 최적화와 저부하에서의 지연시간 최적화 관점에서 분석하였다. 제안된 구조의 지연시간 분석을 위한 근사해석모델을 개발하였으며 그 타당성은 시뮬레이션에 의해 검증하였다.

• 한국통신학회논문지
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• 제30권10C호
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• pp.992-998
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• 2005

본 논문에서는 고정밀 차량위치 추적 기반의 교통신호등 제어를 위한 저전송율 초광대역 무선통신 시스템에서의 Ultra Fast Acquisition 알고리즘을 연구하였다. 현재 CDMA에서 사용되는 acquisition방식으로는 저전송율 UWB시스템에서 회로가 복잡해지고 빠른 acquisition을 기대할 수 없기 때문에 새로운 Ultra Fast Acquisition방식이 필요하다. 기본적으로 Sequential Estimation방식을 사용하며 trinomial m-시퀀스를 사용하여 유비쿼터스 센서 네트워크용 U시스템에서 long PN code를 사용하는 경우에도 회로의 복잡도를 줄이고 FCC Emission limit을 만족시키면서, $1\~3{\mu}sec$이내의 acquisition을 가능하도록 설계하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.687-690
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• 2003

This paper presents the development of Programmable Logic Controller (PLC) and network to design the redundant control system in order to control the high priority process. The industrial process that cannot be shutdown or the effect of the shutting down takes abundantly damage. In this article, we say that the high priority process. The redundant systems are designed for controlling the high priority process that the control system must have many controllers to instead the main controller when it has some error. This paper we designed the redundancy control system by the advantage of the high-speed communication on the PLC’s network. The temperature control system and the traffic light control system used as the case study. Each example processes consist of two sets of controller. Our scheme we can increase the reliability prevents process down time and reduces the cost of opportunity to loss also.

• 전자공학회논문지A
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• 제33A권7호
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• pp.76-91
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• 1996

In this paper, we proposed the new medium access control protocol for the virtual token bus netowrk. The network is applied to inter-processor communication network of large capacity digital switching system and digital mobile system with distributed control architecture. in the virtual token bus netowrk, the existing medium access control protocols hav ea switchove rtime overhead when traffic load is light or asymmetric according ot arbitration address of node that has message to send. The proposed protocol optimized average message delay using cyclic bus access chain to exclude switchover time of node that do not have message to send. Therefore it enhanced bus tuilization and average message delay that degrades the performance of real time communication netowrks. It showed that the proposed protocol is more enhacned than virtual token medium access control protocol and virtual token medium access control protocol iwth reservation through performance analysis.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.1-6
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• 2008

The ubiquitous sensor network technique is widely applied to variety of information fields such as home automations, logistics, traffic controls, public administrations, health and environment monitoring and etc. It is particularly useful in the areas where energy consumption is minimal and where continuous monitoring of the surrounding environments, which generates streams of data, are required. In this study, we have designed and implemented a living environment automatic control system which collects the streams of temperature, humidity, light and noise data of a simulated house setting in real-time fashion, then controls the home environment based on the collected data according to the users favorites. In order to differentiate the proposed system from the currently existing similar system, we have demonstrated not only the feasibility of collecting data using sensor network in the controlled environment but also the ability to control the various household equipments through wireless communications.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1955-1963
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• 2008

How can a train move? While a car is driven by a driver who gets the traffic information and takes the road, a train is operated on the designated(or predetermined) track by the operator or the control center. There have been a great deal of changes and evolutions in the railroad environment. Along with these transitions, there have been also a considerable amount of changes in the control center. There has been no detailed analysis for the control center even though its importance has been recognized. It goes without saying that CCC(Central Control Center)'s importance as the core of the train driving system. Such an importance is true for the automated driving system such as the light rail system. Therefore this paper analyzes the CCC of AREX(Airport Express) from the various aspects, i.e., organization, personnel assignment, the way of working, qualification and job analysis for the operator.

• 한국시뮬레이션학회논문지
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• 제9권1호
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• pp.11-19
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• 2000

The main idea behind the Intelligent Networks (IN) concept is the separation of switching function from the service control, in order to meet various service requirements of subscribers and development of new services in time. The (N+l) architecture of the IN service system consists of front-end processors (FEP) and back-end processors (BEP), which is in service in a domestic telecommunication company, and balances the traffic load for services among the processors. Under this architecture, the IN service system can distribute the traffic load dynamically, and M services are easily launched and manipulated minimizing impacts on the existing services. This paper traces the performance of the (N＋1) structured system by means of the simulation approach, and shed a light on the result.

• 디지털융복합연구
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• 제14권11호
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• pp.241-247
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• 2016

국내 교통제어신호는 주기적인 간격으로 녹색신호로 바뀌는 시스템과 차량의 수가 많지 않은 심야 또는 통행량이 적은 지방도로에서 황색, 적색 점멸신호를 사용하고 있다. 그러나 차량의 수가 많지 않은 심야의 한적한 도로에서 주기적인 신호체계를 사용할 경우 지체 및 정체를 발생하게 된다. 또한 점멸신호를 사용할 경우 충돌사고의 위험성이 크다. 본 논문은 센서 데이터를 포함한 비콘메세지를 분석한 후 신호체계를 재배치하는 반응형 녹색점멸 신호시스템을 제안한다. 제안 시스템은 심야에 간선 도로 및 하위 도로에서 신호가 녹색점멸을 유지하고 있다가 차량이 무선 커버리지 RSE내에 진입하면 비콘메세지를 주기적으로 전송하고 Agent System이 메세지를 분석해 신호를 변경한다. 차량은 변경한 신호 시스템을 따라 차량이 이동하는 시스템이며, 이는 통행량이 적은 도로에서 원활한 흐름과 차량 간 충돌 사고를 예방할 수 있다. 시뮬레이션 결과 성능 면에서 교통 처리량과 평균 대기시간이 기존 신호 시스템보다 10~30%향상되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.115.5-115
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• 2002

In this paper, we introduce a system that detects all kinds of violations at a street intersection such as red light running, speed violation, stop line violation and lane violation by tracking individual vehicles. Two cameras are used for defecting violations. One is an analog camera for real-time tracking and the other is a digital camera for license plate reading. This system is connected to the traffic signal system controller and monitors the red, arrow, yellow and green phases of an approach. Two loops in the road are used to detect vehicle approach and speed. The system takes pictures of all vehicles passing a second loop and tracks the vehicles until they go out a street intersection...