• Journal of KIISE:Software and Applications
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• v.36 no.4
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• pp.283-290
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• 2009

Context-awareness is one of the key features of ubiquitous paradigm. A methodology that is specifying the relationships between the contexts and services needs to be developed to intelligently and sensitively deal with dynamic environment. The existing models on context-aware modeling are difficult to verify the correctness of models with respect to timeliness. In this paper we propose an approach which includes timing constraint in the relations of the context model, and verify its effectiveness using colored Petri-Net. Moreover, a context-modeling toolkit including context-awareness engine and simulator is developed to support agent-based context-aware service. The effectiveness of the proposed methodology is demonstrated using an example of Usilvercare.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.6
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• pp.1551-1559
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• 2007

The purpose of this study is to verify the technical possibilities and advantages of web GIS system, and its practical implementation for space management and information service accessible from anywhere. at anytime using ArcIMS on behalf of university facility management. It is found that the integration of GIS and web technology, in terms of its administrative and public service capabilities, carries many advantages in the aspects of time, cost, and effort saving. Finally, practical system architecture is proposed with its database structuring method for space management of university facility.

• Journal of Digital Contents Society
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• v.10 no.1
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• pp.61-71
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• 2009

While the broadband network and multimedia technology are being developed, the commercial market on digital contents as well as IPTV has been widely spreading. Especially IPTV is providing various useful services since it makes using multimedia contents easier and more convenient by combining the strong points of both TV and PC system. Until now, IPTV system has been focused on VoD service as a general usages. However, various IPTV services are recently demanded since they can have special features for some specific places and occasions. So in this paper, we propose a design of the download based IPTV system using user-specific channel management. At first, program contents previously scheduled by users are downloaded and are played at settop-box according to the prescribed time table. This system has some advantages of giving users easy access to any wanted media contents in anytime that is IPTV's characteristics. And we can increase stability of services by using time slot distributed download for contents. Because this service can be constructed and maintained at relatively low cost, we confirm that this service model is more suitable to some companies with small infrastructure and special purposes. Accordingly, in this paper, we look into necessary elements and define some protocols for system in order to help other developer build this system.

• Journal of the Korean Society for information Management
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• v.28 no.2
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• pp.159-175
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• 2011

The purposes of this study are to evaluate the navigability of three web-based mapping applications and to suggest how to improve the navigability of all web-based mapping applications. With these purposes, this study conducted a web-based survey congruent with a think aloud and systematic observation for individual participants, followed up by a focus group with all participants. Based on the findings, recommendations are proposed for web-based mapping applications that include a standard click and drag panning function in mapping applications, a scaled zooming option, increased text for icons and buttons, and other potential changes to computer hardware for increased navigability in these applications. By improving the navigability of web-based mapping applications, the learning time may be reduced for each application and the speed at which users' geographic information needs are met will be quicker.

• 한국HCI학회:학술대회논문집
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• 2007.02a
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• pp.835-840
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• 2007

현재 이슈가 되고 있는 유비쿼터스 컴퓨팅 환경에서 서비스를 제공함에 있어 사용자의 만족도를 높여주기 위해 서비스의 지능화가 필요하다. 이러한 지능적인 서비스를 제공하기 위해 서비스에 필요한 지식을 논리적으로 표현하고, 체계적으로 추론할 수 있는 방법이 요구된다. 이를 위해 표현 범위가 넓고 유연한 일차 술어 논리(FOL)는 여러 분야에서 사용되었으며, 추론 시스템에 이용되고 있다. 그러나 풍부한 표현 범위는 유비쿼터스 컴퓨팅 환경에서의 오브젝트 관리에 있어 많은 계산비용이 소요된다. 서비스의 빠른 제공을 목표로 하고 있는 유비쿼터스 환경에서 이러한 계산비용은 서비스 제공 시간을 늦추는 요인이 된다. 이러한 문제를 극복하고 지식의 의미를 부여하는 방법으로 Description Logic과 온톨로지가 연구되고 있다. 특히 OWL(Web Ontology Language)은 풍부한 표현력을 제공하고 있으며, W3C에 의해 온톨로지 기술의 표준으로 제안되었다. 그러나 풍부한 표현 범위는 실제 컴퓨팅 환경에서 모두 사용되지 않고, 기술 및 추론의 복잡함으로 overhead가 발생한다. 본 논문에서는 이를 극복하고자 실제 유비쿼터스 환경에서 요구되는 표현 범위를 만족하는 SUNHI의 표현력을 갖는 EOL을 제안한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1373-1379
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• 2011

The SLA (Service Level Agreement) is once determined between service provider and users in B3G networks so that the network service must be provided as QoS management. Here, the network situation is changed as the time flow, and the service environment is also altered. Hence, dynamic QoS management scheme should be considered. In this paper, we propose a handover scheme for dyanamic QoS as the network situation in B3G networks. The heterogeneous networks can be used for dynamic QoS management in B3G networks.

• Journal of Internet Computing and Services
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• v.11 no.5
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• pp.9-17
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• 2010

During the last decade, Internet protocol television(IPTV), broadcasting of multimedia services using well understood Internet technologies, is a fast spreading technology for distributing multimedia content to consumers. As IPTV services advance, an increasing user demand and tremendous content volume of multimedia content cause some difficulties in network resource management. In this paper, we propose an improved load balancing algorithm for video-on-demand(VoD) service. Unlike existing algorithms, the proposed algorithm considers user's behaviors for VoD service, and determines the most efficient allocation of VoD requests by estimating expected server load and expected user waiting time.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.412-415
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• 2016

본 연구에서는 학술정보의 효율적 관리 및 서비스 체제를 수립하고 활용성을 강화하기 위해 논문 자동 수집 및 구축, 논문 투고 및 심사, 전자출판, XML 자동 구축에 이르기까지 전주기 기능 구현에 방안을 제시하고 이를 구현한 사례를 소개하고자 한다. 기존 Peer-Review 시스템은 데이터 수집 및 변환파트와 투고 및 심사, 전자출판 파트, XML 구축 파트 등으로 분리되거나 별도로 운영되어 왔다. 본 연구에서는 이러한 기능을 통합적으로 구현하기 위해 KISTI의 Peer-Review 시스템인 ACOMS와 XML 기반 학술정보서비스 시스템(KpubS) 기능 및 프로세스를 통합한 구현 방안을 제시하고 이를 시스템으로 구현하였다. 그러나 아직까지 원문 PDF를 XML로 완전 자동 변환할 수 있는 기술은 없는 상태로써 반자동 변환 기능을 탑재하였다. 본 연구 내용은 다양한 수집 채널을 통해 입수된 학술정보 및 XML 자료에 대한 입력체계를 제공하고, XML 본문으로부터 메타데이터를 자동 식별 및 추출하여 학술정보 DB를 구축 저장하며, 구축된 DB 및 XML 기반의 전자출판 기능 제공과 함께 웹서비스 단계까지의 전주기 공정에 대한 프로세스 모델 및 시스템에 관한 것이다. 이에 데이터베이스 구축을 위한 시간 및 비용을 절감할 수 있을뿐만 아니라, 시맨틱 태깅 및 수식, 표, 그림 정보 제공 등 이용자에게 다양한 형태의 서비스를 제공할 수 있게 되었다.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.217-226
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• 2006

Intensive studies have been made in the area of N-VOD server Multimedia files in the N-VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Buffer size and disk bandwidth. we propose a efficient VCR-LIKE operations and buffer, disk scheduling policy for multimedia services with management of VOD sever resources. Simulation results show that the rate of buffer usage and service time of proposed scheme are about 18% performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.

• Journal of the Korea Computer Industry Society
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• v.6 no.3
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• pp.379-390
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• 2005

Intensive studies have been made in the area of VOD server Multimedia files in the VOD sever are characterized with the large volume of data, the requirements of synchronization and real-time playback of streams. The basic goal of the study is to find an efficient mechanism to allow maximum number of users under the limited resources such as Buffer size and disk bandwidth. we propose a efficient $pre\_fetching$ policy for multimedia services with dynamic monitoring and management of VOD sever resources. Simulation results show that the rate of buffer usage and service time of proposed scheme are about $28\%$ performance improved than that of traditional methods. This implies that our method can allow much more users for given resources.