• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.131-140
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• 2011

File pollution (i.e., sharing of corrupted files, or contaminating index information with bogus index records) is a de facto problem in many file sharing Peer-to-Peer (P2P) systems in use today. Since pollution squanders network resources and frustrates users with unprofitable downloads (due to corrupted files) and unproductive download trials (due to bogus index records), the viability of P2P systems (and similar distributed information-sharing applications) is questionable unless properly addressed. Thus, developing effective anti-pollution mechanisms is an immediate problem in this literature. This paper provides useful information and deep insight with future researchers who want to design an effective anti-pollution mechanism throughout an extensive measurement study of user behavior and file pollution in a representative DHT-based P2P system, the Kad network.

• Journal of information and communication convergence engineering
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• v.11 no.3
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• pp.173-178
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• 2013

To discover objects of interest in unstructured peer-to-peer networks, the peers rely on flooding query messages which create incredible network traffic. This article evaluates the performance of an unstructured Gnutella-like protocol over mobile ad-hoc networks and proposes modifications to improve its performance. This paper offers an enhanced mechanism for an unstructured Gnutella-like network with improved peer features to better meet the mobility requirement of ad-hoc networks. The proposed system introduces a novel caching optimization technique and enhanced ultrapeer selection scheme to make communication more efficient between peers and ultrapeers. The paper also describes an enhanced query mechanism for efficient searching by applying multiple walker random walks with a jump and replication technique. According to the simulation results, the proposed system yields better performance than Gnutella, XL-Gnutella, and random walk in terms of the query success rate, query response time, network load, and overhead.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12B
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• pp.818-830
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• 2005

Recently, Peer-to-Peer (P2P) overlay networks like CAN, Chord, Pastry and Tapestry offer a novel platform for scalable and decentralized distributed applications. These systems provide efficient and fault-tolerant routing, object location, and load balancing within a self-organizing overlay network. Content Delivery Network (CDN) is an intermediate layer of infrastructure that helps to efficiently deliver the multimedia content from content providers to clients. In this paper, We propose a topology-aware P2P overlay network for CDN, Rosary, in which CDN servers perform Intra-Pastry and Inter-Pastry routing based on a two-level structured overlay network. This proposed system extends pastry by adapting itself to CDN environments, where a semi-hashing based scheme for Intra-Pastry routing is introduced, and dynamic landmark technology is used to construct the topology-aware overlay network. Through simulations on NS-2, it is shown that Rosary is scalable, efficient, and flexible.

• The KIPS Transactions:PartC
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• v.10C no.6
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• pp.793-798
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• 2003

The P2P service is a technology that can share their information with each other who is able to be connected ith a relating program without passing by a server. Since all personal compiters that linked to the internet under the P2P service can opetate as server or a client, they can provide and share both their information and services through the direct connection. Currently, the P2P service is giving an equal privilege to all users for sharing their resources,.Under this situation, a lot of vulnerability against the various sttacks through the Unternet is possoble, more sophisticated security services are necessary. In this paper, We propose and access control schemae using SPKI(Simple Public Key Infrastructure). The scheme designates and access and acces control by providing the certificate to users who request a connection for resource sharing and limits the resource usage of information provider according to the access right that is given to their own rights.

• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.766-769
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• 2003

최근 수 년간 클라이언트/서버 모델에서 발생하는 문제인 서버 병목 현상, DoS(Denial of Service) 공격, 그리고 시스템의 확장성에 따르는 비용 증가 등의 문제를 해결하기 위한 방법으로 P2P(Peer-to-Peer)의 프로토콜 개선과 통신 모델 개선에 대해서 연구가 활발히 진행되고 있다. 본 논문에서는 기존의 멀티캐스트 프로토콜들을 살펴보고 제안하는 멀티캐스트 프로토콜인 GSAKMP(Group Secure Association Key Management Protocol )를 이용한 보안 멀티캐스트 환경을 구현 한다.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.26-35
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• 2010

In this paper, we propose the peer indexing scheme using data dissemination considering content and mobility. The proposed scheme consists of an index table, a buddy table, a routing table to support the cost of data dissemination, the search accuracy and cost. In this proposed scheme, a neighbor peer is recognized through a signal function and the cost of data dissemination is reduced by timestamp message. The transmitted messages are stored in the index structure considering timestamp and weight of interests which improves search accuracy and reduces the cost of search.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1397-1400
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• 2003

JXTA 기술은 네트워크 프로그래밍과 컴퓨팅 플랫폼으로 P2P(peer to peer) 컴퓨팅이나 P2P 네트워킹이라는 영역에서 폭넓게 발생하는 문제를 해결하기 위해 만들어진 것이다. P2P 네트워크 영역과 같은 분산 컴퓨팅 문제를 해결할 수 있는 JXTA 플랫폼을 이용하여 효율적인 이동 에이전트 시스템을 설계하여, 동적으로 경로를 선정하고, 서비스에 부하를 덜 주면서 Peer 에게 서비스를 제공하는 시스템을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.637-641
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• 2006

현재 인터넷 등의 네트워크와 개인 컴퓨터의 발전으로 인하여 피어(peer)들 간의 파일을 공유하는 시스템에 대한 필요가 증가하고 있다. 이 피어들 간에는 이질적 시스템과 환경을 가지고 있다. 이러한 피어들 간의 자료교환은 서로의 의미가 달라지며, 사용자가 원하는 자료를 쉽게 찾을 수 없다. 이 문제점의 해결을 위해 현재 웹에서 사용자가 원하는 자료에 보다 정확하게 응답을 하기 위해 사용되는 온톨로지 개념을 P2P 시스템에 적용하여 각 시스템 또는 사용자간의 시맨틱 갭(Semantic Gap)을 없애고, 이를 위한 파일 온톨로지를 본 논문은 제안한다. 본 논문에서는 RDF를 사용하여 파일 온톨로지 개념을 현재의 P2P 파일 공유 시스템 중 하나인 Tapestry[1]에 RDF를 적용하여 자료 검색 시 사용자가 원하는 자료를 보다 정확하게 응답할 수 있는 효율적인 파일 검색 시스템을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.1-3
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• 2005

현재 P2P(Peer-to-Peer) 환경에서는 많은 허위 데이터가 생성되면서 불필요한 네트워크 트래픽이 증가하는 문제점이 발생하고 있다. 본 논문에서는 이러한 문제점을 줄일 수 있는 FDR(False Data Reduction) 알고리즘을 제안한다. 이 알고리즘은 멀티미디어 콘텐츠 파일의 헤더 정보를 이용하여 데이터 파일에 고유 ID를 부여함으로써 허위 데이터 생성을 방지한다. 또한 허위 데이터로 확인된 데이터는 각 peer에 저장된 데이터 전송경로를 이용하여 허위 데이터를 삭제함으로써 허위 데이터 증가에 따른 네트워크 트래픽을 감소시킨다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.3
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• pp.1402-1408
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• 2013

Document managements are very important in internal communication for good performance on projects. In case of small scale projects, the document management criteria often have very different from each of the cooperation departments and changes of document structure of work process are frequent over a project period. In this thesis, we propose a monitoring system of document management which is based on P2P(Peer-to-Peer). The proposed monitoring system of document management, which is based on P2P, makes up for time limits and a specific work process in small scale project groups. It can be managed focusing on work process and can monitor effectively the status of creations, sharing and distributions of documents. We can be installed at a low cost by using P2P in a small scale project.