• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.364-366
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• 2003

본 논문은 Peer-to-Peer 방식의 어플리케이션 레벨 파일 저장 시스템에서 피어(Peer) 노드의 성능을 고려하는 효율적인 파일 전송 방법을 소개한다. 무선 접속 기기의 보급으로 인해 P2P 네트워크를 구성하는 피어 노드가 무선망을 통해 접속될 가능성이 높아졌다. 기존의 P2P 네트워크에서 멀티미디어 파일 지원 방식은 피어 노드의 성능을 고려하지 않아 피어 노드와 네트워크의 리소스 낭비가 발생한다. 본 논문에서는 에이전트 기법을 이용하여 노드의 성능을 고려하여 멀티미디어 데이터를 지원하는 방법을 소개한다.

• Annual Conference of KIPS
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• 2004.05a
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• pp.515-518
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• 2004

전통적인 Peer-to-Peer 모델에서 정보검색 문제를 해결하기 위한 방법으로는 질의 및 키워드를 각 Peer에 전송하여 해당 질의 및 키워드와 문서들을 비교하는 방법이 대부분이었다. 본 논문에서는 이러한 방법을 확장하여 문서에 대한 의미론적 분석을 통해 검색의 정확성을 향상시키고자 한다. 이를 위해 본 논문에서는 확률적 의미분석 기법을 이용하여 각 Peer에 존재하는 정보에 대한 색인을 작성 한 후, 이것을 Peer-to-Peer 환경에 적용하기 위한 분산 색인 분배 알고리즘을 제안한다.

• Journal of KIISE:Information Networking
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• v.31 no.6
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• pp.573-581
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• 2004

Recently, the rapid growth of Internet technology and the deployment of high speed networks make many kinds of multimedia services possible. Preexisting multimedia services are designed based on the client/server model which has the problems such as the network failure and the low speed communication due to the high load on the central server. In order to solve these problems, peer-to-peer networks are introduced and expanded through Internet environments. In this paper, we propose a pure peer-to-peer network based resource discovery mechanism for multimedia services. In the proposed scheme, each host maintains the location information of resources which are recently requested by other hosts as well as that oi the replicas of local resources. The proposed scheme has the faster response time and incurs the smaller traffic than the preexisting discovery schemes in pure peer-to-peer network environments. Also, by decentralizing the location information and differentiating the reply path, our proposed scheme can solve the search result loss problem that occurs when the network is unsettled.

• Proceedings of the Korea Society of Design Studies Conference
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• 2003.05a
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• pp.244-245
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• 2003

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.4
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• pp.61-70
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• 2005

We propose and implement a flexible secure peer-to-peer(P2P) file sharing scheme which can be used for data sharing among closed user group (CUG) members. When a member wants to share data, notification messages are sent to the members with whom the member wants to share data. Each notification message includes one-time password encrypted with the receiver's public key. A member who received the notification message can download the data by using the one-time password. The proposed scheme provides selective sharing, download confirmation and efficient storage management. In terms of security, the proposed scheme supports authentication, entity privacy, replay attack protection and disguise prevention. We also implement the proposed system and find that the system is very useful among P2P service of closed user groups.

• Journal of Korea Multimedia Society
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• v.10 no.10
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• pp.1328-1337
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• 2007

We describe a method for streaming specific section using the section information among peers on P2P network. As peers tend to extract only the part of contents in which they are interested, an indexed file is created based on the section information of multimedia contents and registered in the search server. If a peer requests the streaming of specific parts of the contents to other corresponding peer using the section information that the server returns, the peer streams only separated section of the multimedia contents according to the information. For this process, we implement a function that a peer's PC can play a role as a server, and the peer streams the separated content based on the section information that the server supplies.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.4B
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• pp.200-207
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• 2007

Many P2P systems which are designed to implement large-scale data sharing have been introduced in internet recently. They exhibit interesting features like sell-configuration, sell-healing and complete decentralization, which make them appealing for deployment in ad hoc environments as well. This paper proposes an Gnutella-based P2P system that can operate efficiently in ad hoc networks. The objectives of this paper are to extend the overall system lifetime, to reduce overheads, and to provide enhanced performance. The proposed system uses an ultrapeer election scheme based on metric values and proactive distribution of ultrapeer information. According to the simulation results, the proposed system can provide better performance than Gnutella in terms of query success rate, query response time, overhead and residual battery power by utilizing network resources efficiently.

• Journal of Korea Society of Digital Industry and Information Management
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• v.7 no.4
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• pp.1-6
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• 2011

In this paper, search-efficient Bi-directional-Chord(B-Chord) is proposed in P2P (peer-to-Peer) overlay network. Chord is the most popular P2P Look-up protocol. However, it applied to the mobile environment, the search success rate become lower and the request delay time increases. That is big problem. Thus, by improving the existing Chord, in this paper proposed B-Chord reduces the request delay time to in a mobile environment. Proposed B-Chord have the two Finger table and can search by selecting Finger table depending on the value of Key. By use these bi-directional, it can reduce the number of nodes Hop and search delay time. Thus, As a result, it will be able to increase the search success rate in a mobile environment.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.327-336
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• 2003

Recently the rapid growth of Internet and the construction of high speed networks make many kinds of multimedia services possible. But most of current multimedia services are designed being by client/server model, which incurs high load of central server. In order to solve this problem, we propose a peer-to-peer network-based discovery mechanism for multimedia services. In the proposed scheme, mobile agents that have autonomy and mobility are used to search the location of resources. Use of mobile agents can solve the loss problem of the search result that occurs when the network is unsettled in pure peer-to-peer network. It also supports interoperability in heterogeneous system environments. In the proposed scheme, each host maintains the location information of resources which are locally requested or recently requested by other hosts. So, the proposed scheme has faster response time than the pre-existing mechanisms in pure peer-to-peer network environments.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.448-450
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• 2007

Peer-to-Peer system has emerged as a popular model aiming at further utilizing Internet information and resources, complementing the available client-server services. However, the mechanism of peers randomly choosing logical neighbors without any knowledge about underlying physical location aware topology can cause serious performance degradation. In this paper, we consider the network distance between peers so that it helps peers select neighbors located at the nearest when they exchange queries for sharing of resources. To reduce the unnecessary signaling traffic and delay of query exchange, we propose a location aware topology based Hybrid P2P system. This system calculates the network distance which combines the direct measurement such as RTT (Round Trip Time) with geographic space of peers using IP address