• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.347-350
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• 2004

In this paper, PDA(Personal Digital Assistants) terminal is proposed to be used for controlling and managing light facilities efficiently by connecting it to a web-based server system and adding additional functions. The control box of current light facilities may be implemented based on a simple On-Off function. The operational quality of the light facilities will be efficiently improved with some practical advantages such as reduction of required facility, manpower and time in managing the lights and control boxes tv using the popular PDA.

• Journal of Information Processing Systems
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• v.6 no.2
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• pp.253-260
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• 2010

Communication devices aim to provide a multimedia service without spatial or temporal limitations in an IP-based environment. However, it is incapable of allowing for fair use by consumers who legally buy content, and damages provider contents through the indiscriminate distribution and use of illegal contents. The DRM system that emerged to solve this problem cannot protect licenses stored on communication devices, and manage licenses by redistribution. This paper proposes a license audit model, which checks for illegal access, modification and redistribution, and reports alert logs to the server.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.1
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• pp.65-75
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• 2003

The internet telephony service is one of the successful internet application services. VoIP is the key technology for the service to come true. VoIP uses H.323 or SIP as the standard protocol for the distributed multimedia services over the internet environment, in which QoS is not guaranteed. VoIP carries the packetized voice by using the RTP/UDP/IP protocol stack. The UDP-based internet services cause the data transmission problem to the users behind the internet firewall. So does the internet telephony service. The users are not able to listen the voices of the counter-parts on the public internet or PSTN. It makes the problem more difficult that the internet telephony service addressed in this paper uses only one UDP port number to send the voice data of all sessions from gateway to terminal node. In this paper, two schemes including the usage of dummy UDP datagrams, and the protocol conversion are suggested. The implementation of one of the schemes, the protocol conversion, and the performance evaluation are described in detail.

• Journal of Korea Society of Industrial Information Systems
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• v.22 no.2
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• pp.15-25
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• 2017

A System can be more Dependable from some types of Threats if the Dependability Level Against the Threat on the System is Increased. However, The Dependability-performance Tradeoff should be Considered because the Increased Dependability may Degrade the Performance of the System. Therefore, it is Efficient to Temporally Increase the Dependability Level to High only when an Threat is Predicted on the System in a Short time while Maintaining the Level in Low or mid in Normal Situations. In this Paper, we Present a Threat Prevention Strategy for a Networked Node by Dynamically Changing the Dependability Level According to the Threat Situation on its Logically/physically Neighboring Nodes. As case Studies, we Employ our Strategy to an Internet Server Against TCP SYN Flood Attacks and to a Checkpoint and Rollback System Against Transient Faults. Our Performance Analysis Shows that our Strategy can Effectively Relieve the Damage of the Failure without Serious Performance Degradation.

• Journal of Biosystems Engineering
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• v.23 no.4
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• pp.391-398
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• 1998

Effective use of agricultural informations is crucial for 21 century farming. An interactive agricultural machinery information system was developed. It consisted of databases, knowledge bases, expert systems, a server engine, clients for a multimedia agricultural machinery information system based on Java and distributed objects technology. It is supposed to be served through a nationwide super information communication network for my farmers to utilize it interactively and quickly. Several user-friendly interface programs for users were developed to use texts, static k dynamic images, and expert systems easily. Tools for providing the informations were built with JAVA. Information providers permitted to access to the system such as agricultural machinery companies can easily add or modify the informations using distributed object technology. This system can interact among three groups : prime information provider (or system manager), permitted information providers, and farmers.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.88-90
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• 2009

This paper proposes the system and method for converting the contents based on DLNA. Digital Media Controller (DMC) compares the media format of content which Digital Media Server (DMS) provides with the media format which Digital Media Renderer (DMR) supports and then, the content is converted dynamically. The interaction between home devices can make a conversion of contents dynamically and it enables people to enjoy the multimedia contents they like to watch whenever/wherever they want.

• Journal of information and communication convergence engineering
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• v.8 no.3
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• pp.295-300
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• 2010

Recent researches of network structure are moving to high-level networks because there are already many research results of low-level network. Especially, current network services has been changed to the multimedia service using multicast routing such as IPTV(Internet Protocol Television) service. And then previous multicast services were provider oriented. So previous multicast structures were organized server/client model. But future multicast services will make user oriented services. Therefore there will be many service providers in the future. At this point, we study P2P network for supporting multi provider. So we research load balancing and contents lookup protocols in P2P network. In this paper, we propose network protocol and system based on super peer P2P for load balancing and efficiently service search. And we considered mobile environment for mobile IPTV.

• The Transactions of the Korea Information Processing Society
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• v.5 no.7
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• pp.1680-1690
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• 1998

멀티미디어 입출력 서버인 MuX는 다양한 입출력 디바이스와의 인터페이스를 위해 장치독립적인 DLM(dynamic Linking Module)을 사용한다. 본 논문에서는 MuX 시스템의 입출력 디바이스 인터페이스 기능을 확장하기 위해서 MIDI(Musical Instrument Digital Interface)형식의 오디오 데이터를 처리할 수 있는 DLM을 추가하였다. MIDI 데이터의 특성과 MIDI 파일 형식을 분석하여 MIDI를 지원하는 디바이스와의 인터페이스를 위한 MIDI DLM(Dynamic Linking Module)과 파일을 지원하는 DLM을 설계하고 구현하였다.

• Convergence Security Journal
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• v.10 no.3
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• pp.9-14
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• 2010

The network architecture and analysis model for evaluating the information security are presented to distribute the reliable and secure multimedia digital contents. Using the firewall and IDS, the function of the proposed model includes the security range, related data collection/analysis, level evaluation and strategy proposal. To develop efficient automatic analysis tool, the inter-distribution algorithm and network design based on the traffic analysis between web-server and user are needed. Furthermore, the efficient algorithm and design of DRM/PKI also should be presented before the development of the automatic information security model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.748-751
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• 2008

인터넷의 급격한 발전에 따라 멀티미디어 정보에 대한 요구가 증대되고 있으며 이와 관련된 이론 및 기술이 발전해 오고 있다. 이런 기술들 중 대표적으로 IP 멀티캐스트, CDN(Contents Delivery Network) 등을 들 수가 있다. 하지만 이런 기술들은 사용자가 많이 위치한 곳곳에 하드웨어적인 장치들을 설치함으로써 초기 고정비용이 매우 크게 들어간다는 단점이 있다. 비교적 적은 초기비용을 들여서 유사한 성능의 멀티미디어 전송 서비스를 제공하기 위한 기술들에 대한 연구가 최근 주목 받고 있으며 이러한 연구들 중에 대표적으로 오버레이 멀티캐스트가 있다. 본 논문에서는 이러한 오버레이 멀티캐스트를 기반한 미들웨어 서버를 개발하여 멀티미디어 정보 전송 서비스를 제공을 함에 있어서의 미들웨어 서버의 가능성에 대해 살펴보고자 한다.