• Journal of Digital Contents Society
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• v.7 no.2
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• pp.89-94
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• 2006

It can be said that P2P means the pattern that every linker could be both a supplier and a customer by means of the direct connection and survey with personal computers out of the concept of server and client. P2P business has been a great impact all over the world. for it came to be possible as the express internet log-on service is getting widely used and the user environment is getting better with the supply of high-tech computer. Recently the various system of P2P has been developed not as the only service of file share between the personal users but as the application of the electronic trade between the companies. This study is to suggest the most effective system that has the function of complement of P2P.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.1286-1287
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• 2012

자원을 효율적으로 관리할 수 있는 분산 처리 분야의 활용도가 높아지고 있는 가운데 P2P 기술의 유용성이 분산 환경에서 입증되고 있다. 이러한 P2P 시스템에서 다양한 컨텐츠를 이용하여 정보 제공의 역할을 하는 서버와 피어들로 구성된 P2P 시스템은 일반적인 자원 보유 서버로 구성된 시스템에 비해 서버의 부하가 적은 것이 사실이다. 본 논문에서는 식당에서 음식 메뉴를 제공함에 있어서 소셜 네트워크 기반의 공동 구매에 있어 개선된 정보와 연계되어 효과적으로 진행되는 P2P 시스템을 제안한다. 소셜 네트워크 기반의 공동 구매 정보는 P2P 시스템을 이용하는 피어에 의해 제공되고, 이러한 중계 정보는 P2P 서버에 의해 제공되는 형태이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.682-685
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• 2007

P2P 기술의 발달로 기존 클라이언트-서버 형태인 중앙 집중형 방식의 단점을 극복하고 있다. 이러한 P2P 기술의 진화로 P2P 응용 기술에 대한 많은 발전이 있었다. 현재 P2P 구조에서 사용자는 P2P 네트워크에 참여하여 자신이 원하는 자료를 찾는 검색과정이 필요하다. 본 논문은 이러한 과정을 최소화하여서 검색과정을 줄일 수 있는 방법을 다룬다. P2P 네트워크에 존재하는 서비스 프로파일 목록들을 서비스를 제공하는 주체가 서비스를 소비하는 주체에게 보내주게 된다면 사용자는 최신의 서비스 목록을 유지하여 서비스 목록 검색 시간을 최소화 시킬 수 있다. 본 논문에서는 P2P 오버레이 네트워크상에서의 서비스 푸시 시스템에 대한 정의, 각 피어들의 행동모델을 정의 및 시스템 설계에 대해서 소개한다.

• The KIPS Transactions:PartD
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• v.14D no.5
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• pp.555-564
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• 2007

Internet streaming systems consist of a media server, a streaming sewer, and terminals. The media server delivers multimedia contents such as video and/or audio to the streaming server, which distributes the contents to terminals as well. Existing Internet streaming systems have a bottleneck problem in the streaming server because of the limit of the processing capacity of the streaming server and therefore a streaming server can not accomodate more terminals than the limit. As a solution to this problem, P2P streaming systems have been lately proposed and investigated, using P2P distributed architectures. Actually, however, there exist many difficulties in the design and implementation of P2P streaming systems, because it needs many real computers and various network constructions. In this paper, we have proposed and defined a P2P streaming system model such as the architectural model, the timing model, the behavior model, and the performance metrics. And also we have implemented an NS2 based P2P streaming system simulator called P2PStreamSim. Finally, we have verified it through test simulations and analyzed the results.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.292-294
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• 2005

The emerging peer-to-peer (P2P) model has recently gained a significant attention due to its high potential of sharing various resources among networked users. Super-peer unstructured P2P systems have been found very effective by dividing the peers into two layers, super-peer and edge peer. Super peer deal with all Queries instead of edge peers. The existing P2P systems assume all super peers have equal roles and capabilities. However, all super peers don't so that edge peers should select the best super peer in order to handle Queries well. In this paper, we suggest the ISP2P (Intelligent Super-peer based P2P) which allows to select the best super peer to the edge peers. We classify super peers according as the capacity of a edge peer to a super peer. We show that considering the quality of a edge peer to a super peer can improve the performance of the response time and bandwidth.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.728-732
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• 2004

It is evaluated that there is infinit capability of creating new e business using P2P program. but the research for the method to protect the copyright of digital contents is urgent even for development of the p2p service because the problem of copyright protection for digital contents is not solved. In this article, we designed the P2P system which cm give the function of security with technology for copyright management which is made with AES algorism based on PKI when users send digital contants to each other in internet.

• Honam Mathematical Journal
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• v.42 no.3
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• pp.569-576
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• 2020

An element x ∈ E is called a norming point of P ∈ P(ⁿE) if ║x║ = 1 and |P(x)| = ║P║. For P ∈ P(ⁿE), we define Norm(P) = {x ∈ E : x is a norming point of P}. Norm(P) is called the norming set of P. We classify Norm(P) for P ∈ 𝒫(²𝑙²_∞).

• Information and Communications Magazine
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• v.31 no.9
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• pp.24-31
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• 2014

P2P기술은 사용자간 콘텐츠 데이터를 공유하기 위해 개발되었다. 그러나, P2P 기술이 저작물의 불법 공유에 주로 사용되고, ISP의 inter-domain 트래픽을 증가시키는 등의 문제로 인해 많은 지탄을 받아왔다. 그러나, P2P 기술이 가지는 높은 확장성(Scalability)과 동시 사용자 수에 비례한 전달 성능 등에 주목하여 P2P의 개념을 다양한 서비스에 접목함과 동시에 inter-domain traffic문제를 해결할 수 있는 방법들이 제시되었다. 이 노력의 일환으로 IETF ALTO WG[1]에서는 ALTO 프로토콜[2]을 2014년 3월에 RFC6708로 제정하였으며, IETF PPSP WG[3]에서는 P2P를 이용한 멀티미디어 스트리밍 프로토콜을 개발하고 있다. 본 고에서는 P2P기반 콘텐츠 전달 기술에 대한 소개와 더불어 IETF PPSP WG에서 진행중인 P2P기반 스트리밍 프로토콜 표준 기술을 분석하고, IETF 표준화 동향에 대해 알아본다.

• YAKHAK HOEJI
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• v.38 no.2
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• pp.140-148
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• 1994

${\beta}-Lactamase$ stability, chemotherapeutic activity, and pharmacokinetics of 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl]thiocarbonylthiomethyl-3-cephem-4-carboxylic acid(CEN1), 7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyrimidyl)piperazinyl]thiocarbonylthiomethyl-3-cephem-4-carboxylic acid(CEN2), pivaloyloxymethyl-7-[(Z)-2-(2-aminothizaole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate(CEN1P), and pivaloyloxymethyl-7-{(Z)--2-(2-aminothizaole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate(CEN2P) were examined. CEN1, CEN2, CEN1P, and CEN2P were very stable to the ${\beta}-lactamase$ obtained from three strains(Enterobacter cloacae P99, Escherichia coli TEM, and Citrobacter freundii). Chemotherapeutic activities$(ED_{50})$ of CEN2 and CEN2P against experimental systemic infections due to Streptococcus pyogenes 77A and Escherichia coli 078 were superior to those of CEN1 and CEN1P, respectively. The $ED_{50}$ values of CEN1, CEN2 were 5.82 mg/kg, 0.89 mg/kg(s.c., S. pyogenes 77A) while those of CEN1P, CEN2P were 14.56mg/kg, 6.40mg/kg(p.o., S. pyogenes 77A), respectively. The pharmacokinetics of CEN1, CEN2, CEN1P, and CEN2P were investigated in mice and rats. In mice, peak blood levels of $1.25\;{\mu}g/ml$ were recorded within 20 min after oral administration of a single dose equivalent to 40 mg/kg CEN1P. Cmax of CEN1P was much higher than that of CEN1 in mice and rats. Oral absorption of CEN2P was much higher than that of CEN2.

• YAKHAK HOEJI
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• v.38 no.2
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• pp.123-130
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• 1994

Physicochemical properties and hydrolysis kinetics of new some oral cephalosporins were examined in buttered solution and human plasma or rat liver homogenate. The test cephalosporins were 7-[(Z)-2-(2-aminothiazole-4-yl)-2- methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazinyl] thiocarbonylthhiomethyl-3-cephem-4-carboxylic acid (CEN1), 7-[(Z)-2-(2-aminoth iazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyrimidyl)piperazinyl]th iocarbonylthiomethyl-3-cephem-4-carboxylic acid (CEN2), pivaloyloxymethyl-7-[ (Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[4-(2-pyridyl)piperazi nyl]thiocarbonylthiomethy1-3-cephem-4-carboxylate (CEN1P), and pivaloyloxymethyl-7-[(Z)-2-(2-aminothiazole-4-yl)-2-methoxyiminoacetamido]-3-[ 4-(2-pyrimidyl)piperazinyl]thiocarbonyl-thiomethyl-3-cephem-4-carboxylate (CEN2P). The partition coefficient(Ko/w) of CEN1P, CEN2P were higher than those of CEN1, CEN2. The calculated pKa values of CEN1, CEN2, CEN1P, and CEN2P were 7.09, 7.75, 4.92, and 5.39, respectively. The hydrolysis of CEN1P and CEN2P were not depend on the composition of pH of the test medium except weak alkaline buffered solution (pH 8.00). CEN1 and CEN2 were very stable in pH 6.80 and 8.00 buffer solutions. CEN1P and CEN2P were rapidly deesterified to CEN1 and CEN2 in human plasma and in rat liver homogenate. Half-lives$(t_{1/2})$ of CEN1 and CEN2 were 3.49 and 4.93 hr in human plasma, 1.47 and 1.26 hr in rat liver homogenate, respectively.