• Proceedings of KHEA Conference
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• 2006.10a
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• pp.145-145
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• 2006

• 한국IT서비스학회:학술대회논문집
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• 2002.11a
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• pp.172-178
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• 2002

본 논문에서는 정보시스템 연속성을 지향하는 백업센터의 아키텍처 설계에 관해 논의한다. 국내구축사례를 중심으로 백업센터의 기반환경 및 아키텍처 유형을 파악하고 이를 분류하고 비교 분석함으로서 보다 이상적인 아키텍처 설계를 위한 기틀을 제공한다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10c
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• pp.41-43
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• 2000

멀티미디어 시스템에서는 미디어 데이터의 연속성을 보장하는 것이 중요한 문제이다. 90년대에 제안된 구역분할 디스크에서 연속성을 보장하면서 멀티미디어를 효과적으로 저장, 전송하기 위하여 새로운 스케줄링 방식과 데이터 블록의 배치가 제안되었다. 이 방식은 구역을 순환하면서 데이터 블록을 배치시키고 SCAN 알고리즘으로 데이터를 읽어 들이는 방식이다. 이 경우 SCAN 알고리즘으로 데이터를 읽어 들이므로 이중 버퍼링(double buffering) 방법을 사용하게 된다. 이중 버퍼링의 데이터를 읽어 들이는 주기와 서비스 주기의 불일치성으로 인하여 새로운 스트림의 요청이 있을 때 기존의 서비스 스트림에 주기시간의 증가로 인한 데이터의 지연문제(jitter)가 발생한다. 본 논문에서는 구역분할 디스크를 이용하는 비디오 서버에서 새로운 요구의 도착으로 인하여 발생하는 데이터 지연 문제(jitter)를 해결하기 위하여 선행 버퍼링이란 기법을 제시한다.

• The Journal of the Korea Contents Association
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• v.8 no.12
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• pp.28-36
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• 2008

In this paper, a service mobility scheme using user's location & service information table management and user recognition skill is proposed to support the movement of the multimedia service user and provide the seamless multimedia service environment in home network. We analyzed the proposed scheme using queueing system and we built test bed for experiment onthe proposed scheme to verify the operation and performance. As a result, we can show the proposed scheme provides a seamless multimedia service through the new client terminal when a user move to the new location and shows the performance completing the service mobility through the new client terminal within the service delay time which is shorter than the service delay time generated in the previous scheme.

• The KIPS Transactions:PartC
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• v.16C no.1
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• pp.117-124
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• 2009

Recently, the application of network technology extends to all areas because of development of digital information technology. Thus, networks are being evolved towards a next-generation communication environments where all information devices, home appliances, and object are connected and interoperated. In order to provide adequate convergence services in IMS-based networks that are the core technology of the next-generation communication environments, seamless service should be possible although the underlying network and the device in use may change in the networks. In this paper, we propose an efficient architecture, algorithm, and protocol of service session control for seamless service in such networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.5
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• pp.1067-1072
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• 2014

As the service continuity of mobile multimedia service is affected by packet loss and delay, the efficient handover control is essentially required. This paper proposes a handover admission control scheme to satisfy service continuity of mobile multimedia services in LTE-Advanced System. In this method, based on context information of mobile terminal and base station changes, the sequence diagrams between the function modules for controlling new sessions and ISHO sessions are proposed. Simulation is done for performance analysis with the measure of transmission delay and packet loss rate.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.544-546
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• 2002

최근 무선 통신 기술이 빠르게 발전하면서, 모바일 사용자들의 다양한 서비스에 대한 요청이 증가하고 있다. 그리고 멀티미디어 서비스는 네트웍 효율성의 측면에서 멀티캐스트 전송 기법이 적합하다. 이에, IETF Working Group에서는 이동 컴퓨팅 환경에서 IP 멀티캐스트를 지원하기 위해 Home Subscription 과 Remote Subscription을 제안하였다[1]. 이 방법들은 각각 장.단점을 가지고 있으나, 호스트에게 연속적인 서비스를 제공하지는 못한다. 본 논문에서는 Remote Subscription에서 제공하는 최적의 경로를 사용하면서, 사용자들에게 멀티캐스트 상에서 연속적인 서비스를 제공할 수 있는 방안에 대해 제시한다. Multicast Agent는 자신이 관리하는 네트웍에 현존하는 사용자들의 멀티캐스트 그룹의 관리와 사용자들을 대신하여 그룹에 가입 및 탈퇴를 행한다. 본 논문에서 제시한 방법은 이동 가능한 지역의 Multicast Agent가 미리 멀티캐스트 그룹에 참가함으로써 기존의 제시된 연구 방법들에 비해 사용자들에게 연속적인 서비스를 제공할 수 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2393-2398
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• 2014

Because each resource in LTE-Advanced system and network's shapes such as bandwidth, error rate change variably, it is judged that it is impossible to control service continuity with procedural, artificial, and static control method applied to the existing voice service. This research suggests a QoS management mechanism to support the service continuity effectively based on policy control. It means a method in which a subscriber's terminal collects information about its current condition and base station around, and a base station, through the data collected by monitoring inner or adjacent base station, shares related data and converges, controlling service continuity on its own.

• Journal of the Korean Society for information Management
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• v.18 no.3
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• pp.87-114
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• 2001

A hybrid information environment can be described as one where an appropriate range of heterogeneous information services is presented to the user in a consistent and integrated way via a single interface. The purpose of this study is to suggest a need of hybrid information services through understanding of the hybrid information environment and hybrid library. Additionally, this study deal with basic concepts of design for a hybrid information service model and address a number of hybrid library projects based on these concepts, such as Agora, BUILDER, HealdLine, HyLife, and MALIBU. Finally, this study survey generic a model of hybrid library and suggest basic principles for building of hybrid information service model, such as integration, seamlessness, authentication, interconnectivity, and personalization of information seeking process environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.850-857
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• 2013

The objective of this paper is to provide service continuity based on an efficient subchannel allocation in OFDMA systems. The resource management for handover are necessary to maintain the QoS requirements of different multimedia applications because the service continuity may be defected by some delay and information loss. Therefore we propose two subchannel management schemes applied to OFDMA systems. Firstly, a superposition allocation of interference subchannels is achieved by modifying a frequency reuse scheme, using co-subchannel interference principle. Secondly for handover applications, we suggest a novel subchannel reservation scheme to adjust the number of allocated channels, depending on the different characteristics and diverse quality of mobile multimedia applications. Simulation results show that the total throughput for the proposed method is increased up to 20% at average and peak arrivals and the handover failure rate is decreased to about 25%, as compared to the conventional method.