• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.902-909
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• 2023

This study evaluated the performance test of a small-sized LTE-Maritime(LTE-M) transceiver that was developed and promoted to expand the use of intelligent maritime traf ic information services led by the Ministry of Oceans and Fisheries with the aim of supporting the prevention of maritime accidents. Accoriding to statistics, approximately 30% of all marine accidents in Korean water occur with ships weighing less than 3 tons. Therefore, the blind spots of maritime safety must be supplemented through the development of small-sized transceivers. The small transceiver may be used in fishing boats that are active near coastal waters and in water leisure equipment near the coastline. Therefore, verifying whether sufficient performance and stable communication quality are provided is necessary, considering the environment of their real usage. In this study, we reviewed the communication quality goals of the LTE-M network and the performance requirements of small-sized transceivers suggested by the Ministry of Oceans and Fisheries, and proposed a test plan to appropriately evaluate the performance of small-sized transceivers. The validity of the proposed test method was verified for six real-sea areas with a high frequency of marine accidents. Consequently, the downlink and uplink transmission speeds of the small-sized LTE-M transceiver showed performances of 9 Mbps or more and 3 Mbps or more, respectively. In addition, using the coverage analysis system, coverage of more than 95% and 100% were confirmed in the intensive management zone (0-30 km) and interesting zone (30-50 km), respectively. The performance evaluation method and test results proposed in this paper are expected to be used as reference materials for verifying the performance of transceivers, contributing to the spread of government-promoted e-navigation services and small-sized transceivers.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.5
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• pp.926-932
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• 2007

Various research groups proposed various architecture of hardware VPN for the high performance VPN system. However, the VPN based on hardware researcher are focused only on the encryption acceleration. Soft based VPN is only useful when the network connection is slow. We have to consider the hardware performance (encryption/decryption processing capability, packet processing, architecture method) to implement hardware based VPN. In this paper, we have analysed architecture of hardware, consideration and problems for high-speed VPN system, From the result, we can choose the proper design guideline.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.459-461
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• 2008

오늘날 전자정부는 초고속 정보통신망과 네트워크, 인터넷 기반기술을 이용한 정부간, 정부와 시민, 기업간 다양한 분야에 원활한 행정서비스를 제공하고 있다. 지금까지 일반 패키지 소프트웨어나 임베디드 소프트웨어 등에 관한 품질평가기술 개발 연구는 다양하게 진행해 왔지만 전자정부 소프트웨어에 대한 연구는 활발하지 못한 실정이다. 본 연구에서는 ISO/IEC 12119와 ISO/IEC 9126 및 ISO/IEC 14598을 기반으로 전자정부 소프트웨어의 품질요구사항을 체계화하고 전자정부 소프트웨어 품질평가를 위한 메트릭을 시험모듈 형식으로 구축하고 이를 적용하기 위한 시험표를 구축하였다.

• The Transactions of the Korea Information Processing Society
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• v.5 no.5
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• pp.1320-1332
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• 1998

We propose Multiph which is a virtual topology for a reliable group communication platform on dynamic high speed network. We also define group communication primitives for transmission of messages and group management. Multiph consists of a set of nodes which are process groups and a set of edges which are the connection between nodes providing the route of messages. Processes can send and receive messages overlapped in a several multicast groups. Overlapped process organizes non-overlapped logical group, which called meta-group. Multiph guarantees ordering of messages that received at the destination group. It has no extra node that decreases system performance. Although the group has dynamic group change to leave and add process, it does not reconstruct the existing platform structure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4A
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• pp.385-392
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• 2006

It is widely accepted that high user densities in mobile multimedia environments can only be achieved with micro- and pico-cell. The smaller cell size causes frequent handovers between cells, and decreases permissible handover processing delay. This may result in the handover failure, in addition to the loss of some packets during the handover. In these cases, re-transmission is needed in order to compensate errors, which in turn triggers a rapid degradation of throughput. In this paper, we propose a new handover scheme for the next generation mobile communication systems, in which the handover setup process is done in advance before a handover request by predicting the handover cell based on mobile terminal's current position and moving direction. Simulation is performed in order to analyze the handover failure rate and packet loss rate. Simulation results show that our proposed method provides a better performance than the conventional method.

• The Journal of the Korea Contents Association
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• v.4 no.2
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• pp.61-67
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• 2004

This paper describes the importance of the network equipment markets and the necessity of the testing and the verification for the network equipments and the effective system for network equipment test. With the rapid internet service development, the demands of the network equipments(for example, router, switching equipment etc.) are expanded. The network equipments request the high love technologies, so the foreign network equipments are prevailed in the domestic market. But the development of the network equipments in korea is in the beginning stage. To deploy the network equipments into the real network the network equipments should be tested and verified by the certified test labs. To get the verification from the foreign test lab, it takes a lot of expenses and times. For the competitiveness of our products in the international markets, the technique of the test and verification on the network equipments should be level-up. This paper investigates the network equipments market condition and the network equipments test condition in Korea. For the competitiveness of our commodities in the international markets, this paper proposes the testing strategy for network equipments.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.881-888
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• 2006

The position of the bridged tap is determined by that of the outlet in most modern apartments, since most of the indoor wiring utilizes the bus wiring structure when deploying the indoor communication line. These bridged taps deteriorate transmission performance in the specific frequency at the time of high-speed multimedia communication, which uses a high frequency bandwidth, since the duality of return loss worsens and line attenuation increases rapidly. As a result, analysis on this phenomenon is required. In this study, the test model is created by modeling the intercommunication facility of the apartment that is the most representative residential house type, and by understanding the structure and the environment of the indoor wiring. Also, how the bridge tap affects performance is analyzed when the VDSL service is provided, so that problems of intercommunication lines can be identified and methods for improving the proper intercommunication line can be suggested, which is suitable for accommodating high-speed multimedia service of the future.

• Journal of the Korea Society of Computer and Information
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• v.4 no.1
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• pp.15-20
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• 1999

In this paper, we propose some essential requirements for CBM(Computer Based Multimedia) based distance education. This is a class of multimedia distance education in which the multimedia technique is combined with the distance home education application that is real time collaborative application on cyber-space using the information super highway. Requirements in this paper is observed standard at ITU(International Telecommunication Union). international standardization organization for multimedia communication. And. a structure for integrated home information service on the information super highway is based on IEEE 1394 serial communication and POF(Plastic Optical Fiber) home backbone that is study for application service according to the multimedia based distance home study system.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.718-723
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• 2006

Optical module plays an important role in the construction of high speed communication network. Laser diode is a component of optical module, and its characteristics are dependent of temperature, so many researches are reported. In this paper, we proposed the electrical equivalent circuit of PBH-LD based on the rate equations. And, the two leakage paths exit outside the active region. One path is converted pn-diode and the other path is converted two transistors using npn-Tr and pnp-Tr. In order to reduce the leakage currents, we observed the dependence of carrier concentrations of current blocking layers using PSPICE simulator.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10a
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• pp.743-746
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• 2000

인터넷의 보급과 초고속 정보통신망의 급속도로 발전함에 따라 학습자와 교수의 상호작용이 가능하며 학술에 흥미를 유발할 수 있는 가상강의 저작도구가 절대적으로 요구되고 있으나 이 저작도구의 개발을 위해 현재는 교사와 학생간의 인터페이스 제공이 미약하고 표준화된 문서 환경과 플랫폼이 없이 서비스를 제공하는 웹 환경으로 인해 개발자들의 작업이 방대해지고 있는 있다. 따라서 최근 컴포넌트 기반 개발 방법론의 대두로 가상강의 저작도구를 위한 교육용 컴포넌트에 관심이 요구된다. 본 논문에서는 컴포넌트 기반의 개발 방법론을 통해 웹 환경에서 구현할 때 적용가능한 강의 저작도구 컴포넌트를 요구 공학 생명주기를 통해서 분석, 설계한다. 요구공학에서 사용자 인터페이스 부분을 가상강의에서 교수, 학습자 측면을 고려하고 비즈니스 로직, 동영상과 슬라이드의 동기화, 오디오, 슬라이드 이미지 등을 요구공학 생명주기에서의 산출된 요구공학 명세서를 바탕으로 분석, 설계한다. 개발된 컴포넌트는 가상강의 저작도구를 지원가능하며. 각 컴포넌트는 교육영역의 애플리케이션에 쉽게 적응 가능함으로써 재사용성, 사용의 용이성과 이식성을 가질 수 있다.