• Korean Journal of Microbiology
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• v.49 no.1
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• pp.99-104
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• 2013

Bacteriophage P2 sir mutants are inefficient helpers for their satellite bacteriophage P4. The term, "P2 sir-associated helper inefficiency" has been used to define this phenomenon and it has been suggested that the DNA sequence difference between the cos region of P2 and that of P4 is responsible. To test this hypothesis, P4 derivative phage, P4 sid71 cosP2, containing the cos region of P2 and sid71 allele was constructed through several in vitro DNA manipulation steps. Its burst size was determined using a one-step growth experiment. The results showed that the substitution of the cos region of P2 for the cos region of P4 in P4 sid71 cosP2 overcame "P2 sir-associated helper inefficiency". P4 sid71 cosP2 stock phages prepared with P2 wild type helper and P2 sir helper were analyzed using a CsCl buoyant equilibrium density gradient experiment. The results revealed that the phage particles containing three copies of the P4 genome were the predominant particles in both cases.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11B
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• pp.750-757
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• 2005

This paper reports on the study of P2P traffic behaviors in a high-speed campus network under a simple firewall which drops packets with default port numbers for the well-blown P2P applications. Among several ways of detecting P2P traffic, the easiest method is to filter out packets with the default port number of each P2P application. After deploying the port-based firewall against P2P-traffic, it is expected that the amount of P2P traffic will be decreased. However, during the eight-month measurement period, three new commercial P2P applications have been identified and their traffic usages have reached up to $30/5.6\%$ of the total outbound/inbound traffic volumes at the end of the measurement period. In addition, the most famous P2P application, eDonkey, has adapted and has escaped detection through port hopping. The measurement result shows that the amount of eDonkey traffic is around $6.7/4.0\%$ of the total outbound/inbound traffic volume. From the measurement results, it is observed that the port-based firewall is not effective to limit the usage of P2P applications and that the P2P traffic is steadily growing due to not only the evolution of existing P2P applications such as port hopping but also appearances of new P2P applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.716-719
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• 2003

P2P (Peer to Peer) is part that is discussed much in the latest Internet and is interested. P2P changes the structure of Client-Server into Information sharing between client that is the structure of p2p. But perfect P2P system has many problems awaiting solution. In this treatise we can realize network communication to compose one virtual server and one virtual client which is intergrated several client and distributed computer that decentralize network traffic into the traffic of several pc by sharing resource and cpu between client. Our nam purpose is not real P2P system but realization, organization of the P2P internet system which is composed by distributed computing and network load balancing in P2P internet system environment.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.6
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• pp.915-920
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• 2011

P2P technology is the concept to share resources efficiently in distributed environments that a lot of research is underway. a lot. In these P2P systems, the server to support the contents-information have less overloads than the composed system as the server to have resources generally. In this paper, we suggest a P2P system to support conveniences to choice time for users that were connected with the information of joint-buying based on social network. Social networks based on co-purchasing information and price alerts using the P2P system is provided by the peer, this relay information is provided by the P2P server.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.3
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• pp.445-449
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• 2011

A P2P technique is the concept to share sources efficiently in distributed environment that is studying a lot. In these P2P systems, the server to support the contents-information have less overloads than the composed system as the server to have resources generally. In this paper, we suggest a P2P system to support conveniences for users that were connected with the information of joint-buying based on social network. The joint-buying information based on social network is supported by peers using a p2p system and these information to intermediate are supported by a P2P server.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.389-396
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• 2006

P2P(Peer To Peer) system, a most attractive file sharing system, is the largest channel of contents distribution and it takes 50% of network traffic. But P2P systems are infamous for used to illegal contents distribution channel not only in music industry, but also in movie industry. But, DRM(Digital Right Management) enabled P2P models are not suggested until now that interrupting illegal contents distribution and keeping advantage of P2P. So in this paper, we suggest a DRM enabled P2P model that can support distributed processing ability and high scalability with no modification in exist P2P model or architecture.

• 한국HCI학회:학술대회논문집
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• 2007.02b
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• pp.728-736
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• 2007

P2P 파일공유는 1999년 처음 등장한 이래 저작권 침해로 디지털 콘텐츠 시장을 파괴하는 '해적'으로 간주 되어왔다. 하지만 최근 들어 P2P 시장의 산업적 가능성을 새롭게 주목하는 움직임이 나타나고 있다. 아울러 학계에서는 P2P의 경제적 영향력을 공급자 편향의 시각이 아닌 소비자 측면을 포함한 균형적 관점으로 바라보기 시작했다. 본 연구 역시 균형적 관점에서 P2P를 바라보려는 접근법의 일환으로, P2P 영화파일 공유 이용자들의 영화소비패턴을 실증적으로 살펴보고자 하였다. 실제 P2P 영화파일 공유 이용자들에 대한 설문결과, 이용자들은 단일한 영화소비성향을 가지고 있지 않았으며 다운로드와 극장 관람빈도가 모두 높은 이른바 '얼리어답터'형과 다운로드를 극장관람의 대체재로 여기는 소위 '해적'형이 공존하고 있었다. 이 중 그간 산업계에서 우려하던 해적형의 비율은 10% 정도로 낮았고, 대부분의 P2P 이용자들은 오히려 일반 극장 관람객보다 더 적극적으로 극장소비를 하는 사람들로 영화산업에 긍정적인 기여를 하는 것으로 밝혀졌다. 이러한 소비자 분석결과는 향후 본격화되고 있는 P2P 다운로드 유료화 시장에 대한 전망을 밝게 하는 것으로, 현재 유료화에 있어 가장 중시해야 할 것은 불법 무료 다운로드에 대한 경계가 아니라, 소비자 편의적인 시스템의 개발임을 시사한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.7
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• pp.1447-1454
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• 2012

Recently P2P is the most popular network service on Internet and is applied various areas such as streaming, file sharing and software distribution, but there are many security threats depending on vulnerabilities by P2P network environments. Conceptually P2P network is a overlay network based on Internet, and it has security concerns of itself as well as those of Internet environments. In this paper, we analyze the vulnerabilities and threats for domestic P2P services through various experiments and describe their risk analysis. We expect that this work contributes to new domestic P2P services in consideration of service qualities and security vulnerabilities.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.1
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• pp.21-28
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• 2006

This paper describes the design and implementation of video conference system using hybrid type P2P(Peer to Peer). The proposed video conference system has hybrid type P2P architecture based on a client-server and P2P(Peer to Peer), where client-server is used for exchange of account management, client list and status information and P2P is used for the real time video conference. The proposed video conference system decreases the traffic of server, and cuts down the load of a network. Because the multimedia data is decentralized to client by P2P. Also, this system is tested by the multi-party video conference system using communication protocol and application software through high speed networks.

• Journal of the Korea Society of Computer and Information
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• v.13 no.3
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• pp.123-130
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• 2008

To avoid some protection systems such as firewall, P2P applications have recently used to apply dynamic port numbers. Reliable estimates of P2P traffic require examination of packet payload, a methodological land mine from legal, privacy technical, logistic, and fiscal perspectives. Indeed, access to user payload is often rendered impossible by one of these factors, inhibiting trustworthy estimation of P2P growth and dynamics. Despite various methods such as port-based and signature-based techniques, it still dose not satisfy the method which uses both qualitative and quantitative aspects. In this paper, a method using SVM mechanism which discriminate the P2P traffic from non-P2P traffics using differences between P2P and other application traffics is suggested. This is a systematic methodology to identify P2P networks, and without relying on packet payload.