• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.700-702
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• 2004

최근 유비쿼터스 네트워크 환경을 통해 새롭고 다양한 서비스가 개발되고 있다. 그 중, 위치기반 서비스(Location Based Services: LBS)는 GPS나 이동 통신망을 사용해 사용자나 사물의 위치를 파악하고 이를 기반으로 유용한 서비스를 제공하는 기술이다. 이 기술은 공공 안전 서비스나 위치 추적, 항법 서비스, 정보제공 서비스 등에 적용되어 사용될 수 있다. 하지만 기존의 위치 기반 시스템은 실내 및 건물 밀집지역에서 위치 인식이 쉽지 않고 사용자의 위치 정보가 누출될 위험성이 있다는 문제점을 가진다. 본 논문에서는 이동 통신망과 무선 근거리 통신망에서 동작하는 이동 에이전트를 이용하여 위치기반 서비스를 구성하였다. 본 기법은 Hybrid Peer to Peer 방식을 이용하여 건물 밀집 지역이나 지하, 실내에서도 정확한 위치측정이 가능하고 개인의 위치 정보도 노출되지 않으며, 나아가 개인 이동 단말기의 상황 인식 컴퓨팅(Context-Aware Computing) 환경 구축에도 도움을 줄 수 있을 것으로 기대 된다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1999.11a
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• pp.37-42
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• 1999

This paper was studied on change for Marine Administration of telecommunications. Analysis method was studied of Policy Delphi. The three kinds of telecommunications network influence on Marine administration is National Information Infrastructure Network, Integrated Services Digital Network and Local Area Network. The five kinds of telecommunications service influence on Marine administration is Telecommuting Service, Electronic Approval Service, Teleconference Service, Electronic Data Interchange Service, and Internet Service. The results of this as follow: First, all Marine agency must be innovation. Second, Marine Administration must be use Telecommunications. Marine Administration must be for customer.

• The Transactions of the Korea Information Processing Society
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• v.4 no.2
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• pp.515-522
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• 1997

A neat prefect stable random access protocol for a broadcast channel,the distributed queuing random access protocol(DQRAP)is presented and evaluated.The DQRAP prootcol utilizes minisolts to provide termaty chan-nel feedback and two distributed queues to:9a) resolve contention and (b) to schedute the transmission of messages.Three minislots are sufficient to resolve collisions faster than the tranmission times of all inboled mecages.Three minislots are suffcient to resolve collisions faster than the tranmission times of all inbolved arrivals when ternary minislot feedback is used.Modelingand simulation indicate that the DQRAP protocol, using as few as three minislits,achives a performance level which approaches that of hypothetical perfect cheduling protocol,ie,the M/D/I system,with respect to propagation delay,thus offers the potential of improved performance over current protocols in satellite,metropolitan and packet radio networks.

• ETRI Journal
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• v.8 no.3
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• pp.129-138
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• 1986

ETRI-NET(ETRI Local Area Network)은 종합 정보통신 시스팀 기술개발 및 연구소 업무 자동화를 위해서 한국전자통신 연구소에 설치 운용중에 있는 광대역 근거리 통신망이다. 본고에서는 ETRI-NET의 시스팀 구성, 주요장비, 장비 설치현황, LAN 이용방법, 타 network과의 접속 등에 관해서 기술한다.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.22-29
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• 2000

In this paper, we analyzed the performance of EY-NPMA(Elimination Yield-Non-preemptive Priority Multiple Access) protocol-channel access control protocol of HIPERLAN(HIgh PErformance Radio Local Area Network) type 1 specification, adopted as european high speed wireless LAN standard by ETSI(European Telecommunication Standards Institute). We established a system model for EY-NPMA protocol analysis, analyzed success probability in a channel access cycle, and derived expressions for the average length of contention phase. Using a M/G/1 model, we approximated the normalized delay, and throughput, and we evaluated these results by simulations.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.12
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• pp.1-9
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• 1999

In this paper, the performance of HIPERLAN(HIgh PErformance Radio Local Area Networks) CAC(Channel Access Control) of ETSI(European Telecommunication StandaTds Institute) in Europe, as High speed wireless LAN, is analyzed and estimated by mathematical approaches. The CAC protocol of HIPERLAN is the EY-NPMA(Elimination Yield-Nonpreemptive Priority Multiple Access) which is transmitted after prioritization, elimination and yield phase. We analyzed channel contention phase composed of elimination and yield phase and then throughput is inspected by simulation. This result is useful to design and implement of HIPERLAN protocol.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.8C
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• pp.801-805
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• 2009

The importance of high-speed networking is ever increasing to better support multimedia application such as video conferencing. It is crucial to synchronize the network so that the delay between computers on the network is minimized. In high-speed LAN, for example, most computers use clocks with almost same frequency to minimize the delay for data transmission. However, because of the deviation of transmitter's and receiver's clock frequency and phase difference there can be a metastability problem. Elasticity buffer is to provide a solution for this situation and this paper presents an implementation is a high-speed elasticity buffer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.10
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• pp.1164-1174
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• 1992

In this paper, an Information Security protocol in LLC/MAC Layer Architecture is discussed. This paper examines the security Vulnerability and threats, the security Service required to protect these threats, and architectural considerations of security protocol in IEEE 802 LAN architecture. To provide an Information security service, an information security protocol(SP2 : Security Protocol 2) PDU construction with LLC/MAC service primitives is suggested. To construct the SP2 protocol, the ECB, CBC mode of DES algorithm and DAA(Data Authentication Algorithm) of FIPS is used. The SP2 protocol suggested in this paper provides data origin authentication, data confidentiality, data integrity service.

• Journal of Information Management
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• v.26 no.4
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• pp.64-99
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• 1995

As advanced information technology has been developing rapidly, libraries are moving from an ownership-centered information service toward information access service. Consequently, integrated automation systems of information centers that give not only cataloging information of their own collections but also various electronic information have appeared. In this study, a model of integrated automation system of an information center is suggested in terms of information types and cost, by taking case studies of some domestic and foreign libraries. Furthermore, the MIPOS Information & Resource Center System of POSCO Group is introduced as a good example of integrated automation systems in Korea.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.630-634
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• 2004

This paper describes the design of a two stage 1V power supply SiGe Low Noise Amplifier operating at 5.25 GHa for 802.lla wireless LAN application. The achieved performance includes a gain of 17 ㏈, noise figure of 2.7㏈, reflection coefficient of 15 ㏈, IIP3 of -5 ㏈m, and 1-㏈ compression point of -14㏈m. The total power consumption of the circuit was 7 mW including 0.5mW for the bias circuit.