• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.222-224
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• 2002

This paper investigates the adaptive control of a fuzzy logic based speed and flux controller for a vector controlled induction motor drive. A model reference adaptive scheme is proposed in which the adaptation mechanism is executed by fuzzy logic based on the error and change of error measured between the motor speed and output of a reference model. The control performance of the model reference adaptive control(mAC) fuzzy controller is evaluated by simulation for various operating conditions. The validity of the proposed MRAC fuzzy controller is confirmed by performance results for induction motor drive system.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.505-509
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• 2007

Proxy Mobile IPv6 (PMIPv6)는 Mobile Node (MN)가 스스로 이동성을 지원하지 않더라도 Mobile Access Gate가 MN대신 이동성을 처리하여 IPv6 이동성을 지원하는 기술이다. 좀 더 향상된 핸드오버 성능을 얻기 위해 Proxy Mobile IPv6에서도 버퍼링을 통한 패킷 손실을 줄이는 기법을 사용할 수 있다. 하지만, IEEE 802.11 네트워크에서는 Handover 발생 직전에 MN이 어떠한 통보도 AP로 하지 않기 때문에 Handover시에 패킷 손실을 줄이기 위한 패킷 버퍼링 방법을 사용하기가 어렵다. 본 논문에서 PMIPv6에서 MAG와 AP가 MN의 이동성을 감지하여 버퍼링을 시작하고 Handover가 발생하였을 경우에 대비해 버퍼링을 하는 Cross-layer 버퍼링 방법을 제안한다. 이를 통해 PMIPv6에서도 MN의 변경 없이 Handover시에 발생하는 패킷 손실을 최소화 할 수 있다. 또한 간단한 성능 비교를 통하여 제안 방법이 기존 PMIPv6보다 우수함을 알 수 있다.

• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1177-1188
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• 1999

Continuing advance in computers and MIDI devices has accelerated research on the computerized music technology, Realization of high speed computer communication networks facilitated on-line computer music systems, which needs to send a volume of multimedia data. This paper presents the design and implementation of the Remote Concert Education System which helps users practice ensemble without gathering in a room. The system maintains the music database, identifies tones and measures of the melody played with different instruments, check the correctness on-line, and finally provides the analysed results of the ensemble. The developed system can be used as a supporting system for music education if high speed communication network is available.

• Journal of the Korean Professional Engineers Association
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• v.27 no.2
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• pp.42-54
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• 1994

Nowadays communication network is steadily changing from a main body of telephone to a network which is creating new services such as multimedia etc. Jhis article introduces a bud of new service and new network which are able to sustain the above service. Including Korea, world advanced countries have been digitatizing their network with N-ISDN (narrowband ISDN) by e.g. 64K b/s and 1.5M b/s. New service by N-ISDN are extraordinary, though it can not solve all kinds of services. To solve these problems, a solving platform should be constituted. B-ISDN(broadband ISDN), as a platform has to be built to deal with almost all uinds of services, whatever the communication speed, communication mode or communication quality may be. Korea Telecommunication Authority(KTA) opened the narrowband ISDN(N-ISDN) at the end of 1993. This was one step previous opening of the broadband ISDN(B-ISDN) service scheduled to be rendered in 2001. B-ISDN, receiving and transmitting by far more information with high speed than the N-NSDN does, is one of G-7 Progects which the Korean government is driving foreward to raise the national scientific power to seven advan ced countries. This is also linked with an extremely high speed information network scheduled to be built by the Ministry of Communications in 2015.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.11
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• pp.1443-1445
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• 2016

In this paper, we propose a exclusive-OR TCP coding technic imply with TCP Hybla on split PEP for enhancing the file transfer speed of the satellite communication. To evaluate performance of the proposed method, we set up a test-bed of satellite communication network. As a result of the performance evaluation, the file transmission speed enhanced more than 12% within high packet loss range. Therefore, we can expect that the proposed methodology could contribute to enhancing of data transmission speed in the satellite communication.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.2
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• pp.50-58
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• 1996

This paper proposes the channel-access protocol suitable to a very high speed photonic WDM network with star configuration, which can provide a high channel utilization and insensitivity to the propagation delay. The proposed protocol employs a control channel and a simple status table to deal with the propagation delay which has been a major limiting factor in the performance of the very high speed optical communication networks. The control channel transmits control information in order to reserve access on data channels, and each node constitutes a status table after the reception of control pckets which holds information about the availbility of destination node and data channel. The proposed protocol is insensitive to the propagation delay time by removing necessity of the retransmission and by allowing parallel transmission of control packet and data packets. It is proved in analysis and discrete event simulation that the proposed protocol is superior in throughput and mean delay, especially at the high load conditions compared to the existing high speed channel-access protocols.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.212-215
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• 1999

High-speed device is essential to optoelectric IC for optical storage system such as CD-ROM, DVD, and to ADC for high-speed communication system. This paper represents the BiCMOS process which contains high-speed SAVEN bipolar transistor and analyzes the frequency and switching characteristics of it briefly. Finally, to prove that the SAVEN device is adequate for high-speed system, latched comparator operating at 500MHz is designed with the SPICE parameter extracted from BiCMOS device simulation.

• The KIPS Transactions:PartA
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• v.8A no.2
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• pp.147-156
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• 2001

A high performance routing switch is an essential device to either the high performance parallel processing or communication networks that handle multimedia transfer systems such as VOD. The high performance routing chip called STC104 is a typical example in the technical aspect which has 32 bidirectional links of 100Mbps transfer sped. It has exploited new technologies, such as wormhole routing, interval labeling, and adaptive routing method. The high speed router has been applied into some parallel processing system as a single chip. However, its performance over the various interconnection networks with multiple routing chips has not been studied. In this paper, the strucrtures and characteristics of the STC104 have been investigated in order to evaluate the high speed router. Various topology of the STC104, such as meshes, torus, and N-cube are defined and constructed. Algorithms of packet transmission have been proposed based on the interval labeling and the group adaptive routing method implemented in the interconnected network. Multicast algorithms, which are often requited to the processor networks and broadcasting systems, modified from U-mesh and U-torus algorithms have also been proposed overcoming the problems of point-to-point communication.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1632-1639
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• 2004

The exist email program between Ship and Land has developed to reduce communication fee because of high satellite communication cost and low speed. Owing to this proper, the exist program has less flexibility and high speed. but to add or change functions is not easy. and it also have many difficulties for programmer to develop marine application because of delicate Satellite Radio communication. In this paper we design new protocol which consist of packet to give flexiblity and implement windows service program for programer to make marine applications easily like monitoring data, DB for Ship Management System, Planned Maintenance System.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4B
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• pp.593-603
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• 2000

In this paper, a dynamic route control scheme to increase speed of data communication over public network is presented. And a new structure of gateway which is suitable for the public network environments is proposed and analyzed. For dynamic allocation of transmission routing resources of the gateway and improvement of call processing ratio of the system, virtual queue is used. As results, route utilization ratio of the proposed scheme can be improved up to 60% as compared to the conventional fixed route control scheme. For the case of limited number of routes, it provides high speed data communication while maintaining delay time as low as possible. In addition, as the allocation period at call access node can be varied with the traffic in the proposed scheme, various traffics can be applied easily. Thus, it can be expected that the presented dynamic route control gateway may be suitable for application in high speed data communication over public network.