• 한국철도학회논문집
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• 제6권2호
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• pp.135-141
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• 2003

According to the computerization of railway signaling systems, the interface link between these signaling equipment is also replaced by digital communication channel, expecially communication link for interface between EIS and LDTS, but there are some problems in the present state of railway signaling. First of all, different communication protocol is applied to interface between above two signaling equipment although they have same functions. The other is that the communication protocol currently used in railway field has some unreasonable points such as structure, formation of byte, error correction scheme and etc. To solve these problems, the standard communication protocol for railway signaling is designed. The structure of designed communication protocol and the results of performance analyses are represented in this paper. It will be expected the increase of safety, reliability and efficiency of maintenance of signaling system by using of the designed communication protocol for railway signaling.

• 한국철도학회논문집
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• 제7권2호
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• pp.114-119
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• 2004

According to the computerization of railway signalling systems. the communication protocol for interface between these systems are required. Therefore the new communication protocol for railway signaling system is required. Generally, there are two verification method for new designed protocol in the industrial and academic fields. One is the laboratory testing method which is very popular and general technique. In our research the comparison between existing and new designed protocol for signaling is described and the verification test results are also represented. From these laboratory test, we are verified the conformance of new designed protocol. Another method is verified by formal method. The format verification method is widely used at safety-critical system design but this approach is nor popular at verification communication protocol. However it is very important to verify the safety of new designed protocol for railway signaling system because signaling systems are very safety-critical systems. So, the methodology for formal verification of designed protocol is also reviews in this paper.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권6호
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• pp.380-387
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• 2004

In accordance with the computerization of railway signaling systems, the interface link between the signaling systems has been replaced by a digital communication channel. At the same time, the importance of the communication link has become increasingly significant. However, there are some questionable matters in the current state of railway signaling systems in KNR. First, different communication protocols have been applied to create an interface between railway signaling systems although the protocols have the same functions. Next, the communication protocols currently used in the railway fields have some illogical parts such as structure, byte formation, error correction scheme, and so on. To solve these matters, the standard communication protocol for railway signaling systems is designed. The newly designed protocol is overviews in this paper. And the simulation is performed to analysis the performance of data link control for designed protocol. According to this simulation, it is identified that the link throughput of new protocol is improved about 10% and the frame error rate is improved than existing protocol. And it is verified the safety and liveness properties of designed protocol by using a formal method for specifying the designed protocol. It is expected that there will be an increase in safety, reliability and efficiency in terms of the maintenance of the signaling systems by using the designed communication protocol for railway signaling.

• 한국해양공학회지
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• 제11권4호
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• pp.180-188
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• 1997

This paper proposes a new efficient MAC(Media Access Control) protocol to establish the ultrasonic communication network for underwater vehicles, which ensures a certain level of maximum throughput regardless of the propagation delay of ultrasonic and allows fast data transmission through the multiple ultrasonic communication channel. A MAC protocol for underwater communication network that allows 'peer-to-peer' communication between a surface ship and multiple underwater systems is designed, and the proposed control protocol is implemented for its verification.

• 제어로봇시스템학회논문지
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• 제12권11호
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• pp.1144-1155
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• 2006

Digital communication networks have become a core technology in advanced building automation systems. BACnet(Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet adopts Master-Slave/Token-Passing(MS/TP) protocol as one of its field level networks. In this study, we introduce a method of implementing a bandwidth allocation scheme in the MS/TP protocol. The bandwidth allocation scheme improves the capability of real-time communication of the original MS/TP protocol. The bandwidth allocation scheme introduced in this paper can be easily implemented in the existing MS/TP protocol with a slight modification. In this study, we actually developed the hardware and firmware of the modified MS/TP communication module in which the bandwidth allocation scheme is implemented. Using the modified MS/TP communication module, we developed an experimental model in order to examine the validity of the bandwidth allocation scheme in the MS/TP protocol. Experimental results show that the modified MS/TP protocol satisfies the requirements of real time communication for periodic and urgent messages of BACnet communication services.

• 한국통신학회논문지
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• 제15권4호
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• pp.331-340
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• 1990

통신 프로토콜의 설계에 있어 설계 과정의 단순화와 설계된 프로토콜의 논리적 정당성 입증은 중요한 과제이다. 본 논문에서는 FSM을 이용한 통신 프로토콜 설계 과정 효율화를 위한 합성방법을 제안한다. 통신 프로토콜의 속성 정보를 묵시적으로 표현하여 설계 과정이 단순화되도록 기존의 FSM을 확장시켜 CFSM 을 저의한다. 통신 프로토콜의 설계자는 FSM을 이용하여 오류를 고려하지 않은 한 통신 기계 M 만을 기술하며, 동기화를 보장받는 두 통신 기계 M'과 N'이 합성되며 M'과 N'이 오류 회복 기능을 갖도록 오류 회복용 변환 규칙을 적용하여 최종 프로토콜 EM'과 EN'을 얻는다.

• 한국멀티미디어학회논문지
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• 제25권1호
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• pp.61-71
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• 2022

When communication such as light, radio wave, or magnetic field is used underwater, the communication distance is very short, so sound waves are mainly used. However, by combining the strengths of each medium and communicating, stable communication may be possible. Underwater multi-media communication requires a protocol stack that supports it, which is very complex. To this end, this paper proposes a standard protocol stack and modeling technique to enable easy protocol stack modeling for the purpose. In fact, in this paper, a random model was created and analyzed through the proposal of modeling elements and similarity measurement methods, and as a result, it was analyzed that it was very helpful in creating a new model based on a standard model.

• 대한전자공학회논문지TC
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• 제40권9호
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• pp.349-357
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• 2003

전력설비의 용량이 커지고 전력계통이 복잡해짐으로서 고품질과 안정적인 전력공급을 하기 위해 각 계층간에 연계되는 데이터를 에러 없이 처리하는 프로토콜을 요구하게 되었다. 그러나 서울(EMS)과 광주(RCC) 또는 RCC와 SCC에 사용하고 있는 HDLC나 TCP/IP 통신 프로토콜은 속도의 지연, 에러 발생 등으로 신뢰성을 감소시키고 있다. 이론 개선하기 위해, 본 논문에서는 ICCP 통신 프로토콜을 적용하여 전력 설비의 원거리 제어를 위한 전력 통신시스템을 구현하였다. 오류보정을 위해서 프로그램을 수정하였으며, BLT 최적 조건을 적용하여 구현하였다. 전력통신 시스템에 ICCP 프로토콜을 적용하였을 경우 HDLC와 TCP/IP 프로토콜을 적용한 경우보다 에러가 감소하였다.

• 한국철도학회논문집
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• 제10권3호
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• pp.365-371
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• 2007

The communication protocol for interface among railway signalling systems is designed and established as national standard in Korean from a few years ago. So the communication link for information transmission among railway signalling system can be a good example of application of this standard. Communication protocol which is standardized among Korean railway signalling is considered to apply information transmission. And we confirmed there is no the states of deadlock of livelock in std. protocol which is applied formal verification which is one of the analytic method for inspection of safety characteristics in the design course of protocol. But the safety of protocol has to necessarily accomplish this normal analysis approach about satisfying requirement matters with such this analytic approach. In this paper we analyzed the safety characteristics of standard protocol for Korean Railway signalling through the requirement matters for safety transmission of railway transmission system which is required in international standard. So through this study we confirm whether it satisfies safety requirement matters of the level which require in international standard and tried to confirm whether standard protocol has enough safety character in the real railway field.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권11호
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• pp.660-668
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• 2005

Digital communication networks have become a core technology in advanced building automation systems. BACnet (Building Automation and Control networks) is a standard data communication protocol designed specifically for building automation and control systems. BACnet adopts Master-Slave/Token-Passing (MS/TP) protocol as one of its field level networks. Tn this study, we introduce a method of implementing bandwidth allocation scheme in the MS/TP protocol. The bandwidth allocation scheme improves the capability of real-time communication of the original MS/TP protocol. The bandwidth allocation scheme introduced in this paper can be easily implemented in the existing MS/TP protocol with a slight modification. In this study, we examined the validity of bandwidth allocation scheme using simulation models. The results from the simulation experiment show that the proposed scheme satisfies the requirements of real-time communication.