• Journal of the Korean Society for Railway
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• v.6 no.2
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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.

• Journal of the Korean Society for Railway
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• v.7 no.2
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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.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.6
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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.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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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.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.4
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• pp.331-340
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• 1990

In communication protocol design, it is important that design procedure is simple and result protocol must be correct. This paper presents a communication protocol synth-sizing algorithm, which enhances productivity of protocol design, using CFSM. CFSM is defined as extended FSM for representing protocol information and simplification. In this method protocol designer descripts only one communication machine with out error consideration using FSM, then two communication machine M' and N' are generated. And then transformation rules for error-recovery converts M' and N' to EM' and EN' which are logically correct.

• Journal of Korea Multimedia Society
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• v.25 no.1
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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.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.9
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• pp.349-357
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• 2003

Because of capacity of the electric power equipment grew larger and the electric power system was complicated, it was required a protocol to process data without the errors in order to supply the high quality and stable electric power. However, HDLC and TCP/IP communication protocol using between Seoul EMS and Kwangju RCC (or between RCC and SCC) is decreasing reliability by the delay of speed and the occurrence of errors. In this paper, we applied ICCP(Inter-Control Center Communication Protocol) communication protocol in order to improve them and implemented an electric power communication system for remote control of the electric power equipment. Also, we modified program for error correction and implemented the system using the most suitable BLT. The errors were more decreased in case of ICCP protocol than HDLC protocol and TCP/IP protocol applied to the electric power communication system.

• Journal of the Korean Society for Railway
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• v.10 no.3 s.40
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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.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.11
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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.