• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.600-613
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• 1999

This paper focuses on development of a performance manager for IEEE 802.4 token bus networks to serve large-scale integrated systems. In order to construct the management algorithm, the principles of fuzzy logic, genetic algorithm, and neural network have been combined to represent human knowledge and to imitate of human inference mechanism. Through the simulation experiments, it is shown that the proposed performance manager is capable of improving the network performance without a priori knowledge.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.10
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• pp.2620-2633
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• 1996

In this paper, a new high-speed local area network using a dual mode switching access (DMSA) protocol implemented on a dual unidirectional bus is described. By utilizing the implicit positionalordering of stations on a unidirectional bus, the proposed system switches between random access mode and the token access model withoug unnecessary delay. Therefore, unlike other hybrid systems such as Buzz-net and Z-net, DMSA does not show a rapid degradation in performance as the load increases. We obtain the average channel utilization and the average access delay by using a simplified analytic model. The numerical results obtained via analysis are compared to the simulation resuls for a partial validation of the approximate model. The performance characteristics of DMSA are superior delay-throughput characteristics at light and medium loads, compared to compared to other LAN systems, and the capability of providing a single active station with full capabity of the channel.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2212-2215
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• 2002

This dissertation suggests and implements a middle level network which is called PICNET-NP (Plant Implementation and Control Network for Nuclear Power Plant). PICNET-NP is based partly on IEEE 802.4 token-passing bus access method and partly on IEEE 802.3 physical layer. For this purpose a new interface a physical layer service translator, is introduced. A control network using this method is implemented and applied to a distributed real-time system. To verify the performance of proposed protocol experimental were carried out, and the following results are obtained. 1) proper initialization of the protocol. 2) normal receiving and transmission of data. 3) proper switching of transmission media in case of a fault condition on the one of transmission media. The proposed protocol exhibits the excellent performance in the experimental system. From the test results in the experimental system, the proposed protocol, PICNET-NP, can be used for the upgrading of a nuclear power plant and the distributed control system in the next generation of nuclear power plant.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.755-760
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• 1990

In this paper, the Mini-MAP network interface units are implemented for the IBM PC, general purpose, PLC, and robot respectively. The token bus controller, MC68824 is used to realize the IEEE 802.4. A protocol for the message exchanges between some automated devices called MMS is implemented where 76 services of total 86 MMS services are included.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2015-2020
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• 2008

Real-time communication network is important for KTX high speed train system because small problem can make a huge accident. Communication network for KTX high speed train system consists of IEEE 802.4 token bus network and FM0 encoding. The network device is developed by using MC68824 TBC, MC68185 TPM and MC68020 MPU. The network device make available to analysis of the network protocol among vehicles for Kyung-Boo high-speed train system.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.745-748
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• 1990

MMS (Manufacturing Message Specification) is a communications standard of MAP (Manufacturing Automation Protocol), which is a Network Protocol for Industrial Automation. In the environment of Mini-MAP, MMS is situated in the application layer and on the LLC (Logical Link Control) layer. In this paper, MMS software is implemented on the basis of ISO DIS 9506. The implemented software was tested with Token Passing Bus Network Interface Unit, which was designed in our laboratory and performs the actions of layer 1 and 2.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2419-2422
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• 2000

A distributed real-time system that is being used now is usually divided into three level : higher level, middle level, and lower level. The higher level network is usually called an information network, the middle level is called a control network, and the lower level is called a field network or a divice network. This dissertation suggests and implements a middle level network which is called PICNET-NP (Plant Implementation and Control Network for Nuclear Power Plant). PICNET-NP is based partly on IEEE 802.4 token-passing bus access methed and partly on IEEE 802.3 physical layer. For this purpose a new interface, a physical layer service translater, is introduced. A control network using this method is implemented and applied to a distributed real-time system.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1999.11a
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• pp.143-148
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• 1999

A distributed real-time system that is being wed now is usually divided into three level : higher level, middle level, and lower level. The higher level network is usually called an information network, the middle level is called a control network, and the lower level is called a field network or a divice network. This dissertation suggests and implements a middle level network which is called PICNET-NP (Plant Implementation and Control Network for Nuclear Power Plant). PICNET-NP is based partly on IEEE 802.4 token-passing bus access method and partly on IEEE 802.3 physical layer. For this purpose a new interface, a physical layer service translator, is introduced. A control network using this method is implemented and applied to a distributed real-time system.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.659-665
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• 2003

This paper presents a Train Communication Network simulator (TCNS) that can be used to evaluate the performance of TCN. TCN was accepted as the standard of the protocol for the communication network in trains. We carry out some simulation tests using the TCNS to show practical uses of the simulator. Results of some simulation tests are also reported. This paper presents a Train Communication Network simulator(TCNS) that can be used to evaluate the performance of TCN. TCN was accepted as the standard of the protocol for the communication network in trains. TCN of fieldbus was adopted as international standardization IEC 61375 in 1999. It has been operating on G7 train in korea. This paper developed TCNS(Train Communication Network simulator) as a simulator for performance evaluation. We can verify TCNS for preventing many kinds of occurring problems between the devices in data-communication. This study was developed TCNS as a simulator for the performance evaluation. We analyzed correlation between token, transmission data per paket and transmission speed of bus, through the TCNS, also analyzed result according to error rate of TCN. We carry out some simulation tests using the TCNS to show practical uses of the simulator. Results of some simulation tests are also reported.