• Proceedings of the KIEE Conference
• /
• 2006.04a
• /
• pp.159-161
• /
• 2006

The peer-to-peer (P2P) systems have Brown significantly over last few years due to their hish potential of sharing various resources. Super-peer based P2P systems have been found very effective by dividing the peers into two layers, SP (Super-Peer) and OP (Ordinary-Peer). In this paper, we present ISP2P (Intelligent Super-peer based P2P system), which allows us to choose the best SP. Through analyzing capacity and similarity between SP and OP, we can help OPs to select the most appropriate SP respectively. Proposed system can improve the performance of the average response time by superior SP, reduce the bandwidth cost by small path length due to content similarity and solve frequent SP replacement problem by considering similarity of user behavior.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.45 no.2
• /
• pp.10-17
• /
• 2008

In this paper, we propose an efficient data replication strategy based on Peer-to-Peer which improves the performance of Data Grid system. The key idea of this replication strategy is to add the Peer-to-Peer concept for reducing data transmission restriction caused by hierarchical topology. And, it makes the nodes can store data replica to set a critical section at the storage of client level nodes. Therefore, it is possible to transmit the data replica between client level nodes and from client level nodes to upper data replication server. It is more effective to transmit data replica between client level nodes than transmitting data replica 1mm data server or data replication server with respect to minimize the transmission time. This results in improving the performance of Data Grid system. Through simulation, we show that the proposed data replication strategy based on Peer-to-Peer improves the performance of entire Data Grid environment compared to previous strategies.

• Journal of Korea Multimedia Society
• /
• v.12 no.5
• /
• pp.717-727
• /
• 2009

P2P (Peer-to-Peer) network depends on cooperation of peers considerably. However, some peers do not share files at all and only download files. Peers also share low quality files or unpopular files. These selfish behavior of peers is referred to 'free riding'. The free riding of peer may decrease participation of other peers or the system performance. In this paper, we propose an incentive mechanism, called IcMFS (Incentive Mechanism for File Sharing System), which provides the correct use of incentive mechanism using trust peer, computes contribution values referring behavior of peers and rewards peers. The proposed mechanism assigns bandwidth and TTL(Time-To-Live) to a peer and differentiates the use of service. A case study on simulations shows the service differentiation according to the contribution value of peer, the correct use of incentive mechanism using trust peer and the advantage by use of trust peer. To prove the stability of proposed mechanism, we also show the disadvantage that a peer receives from the incorrect use of incentive mechanism.

• Journal of the Korea Society of Computer and Information
• /
• v.11 no.5 s.43
• /
• pp.29-37
• /
• 2006

The distributed system is used that it's features of the fault tolerance and good performances. One of the distributed systems, a peer-to-peer tech, has high availability to share resources. However when peers wanna share resources, it isn't online like the peer using resources of the search time. Therefore we usually use the re-transmission method to download all resources. It's not good at the performance of the peer-to-peer system so we need to good solution. In this study, we wanna use the peer-to-peer system with the partner peer that works same download method simultaneously. We wanna have the effective performance to reduce the search stage additionally.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.16 no.6
• /
• pp.65-73
• /
• 2016

Peer-to-Peer (P2P) systems with super-peer overlay networks show combined advantages of both hybrid and pure P2P systems. Super-peer is a special peer acting as a server to a cluster of generic peers. Organizing a super-peer network is one of important issues for P2P systems with super-peer networks. Conventional P2P systems are based on two-level hierarchies of peers. One is a layer for generic peers and the other is for super-peers. And it is usual that super-peer networks have forms of random graphs. However, for accommodating a large-scale collection of generic peers, the super-peer network has also to be extended. In this paper, we propose a scheme of hierarchically constructing super-peer networks for large-scale P2P systems. At first, a two-level tree, called a simple super-peer network, is proposed, and then a scheme of generalizing and then extending the simple super-peer network to multi-level super-peer network is presented to construct a large-scale super-peer network. We call it an extended super-peer network. The simple super-peer network has several good features, but due to the fixed number of levels, it may have a scalability problem. Thus, it is extended to k-level tree of a super-peer network, called extended super-peer network. It shows good scalability and easy management of generic peers for large scale P2P system.

• The KIPS Transactions:PartA
• /
• v.11A no.7 s.91
• /
• pp.511-520
• /
• 2004

A peer-to-peer model is very useful in solving the server link bottleneck problem of a client-server model. In this work, we discuss the problems of distributing multimedia content over peer-to-peer network. We focus on two problems in peer-to-peer media content distribution systems. The first is the transmission scheduling of the media data for a multi-source streaming session. We present a sophisticated scheduling scheme called fixed-length slotted scheduling, which results in minimum buffering delay. The second problem is on the fast distribution of media content in the peer-to-peer system that is self-growing. We propose a mechanism accelerating the speed at which the system's streaming ca-pacity increases, called FAST.

• Proceedings of the Korean Information Science Society Conference
• /
• 2002.10e
• /
• pp.460-462
• /
• 2002

컴퓨터 네트워킹의 새로운 패러다임으로 떠오르고 있는 P2P(Peer-to-peer)통신은 기존의 서버-클라이언트 모델의 한계점을 극복하는 많은 해법을 제시하고 있다. 이에 최근여러 가지 플랫폼의 각기의 서비스를 제공하는 애플리케이션들이 속속 등장하고 있다. SunMicro systems에서 시작되어 현재 Open Project로 진행중인 Project JXTA는 이러한 분산 Computing, 특히 Peer-to-Peer Computing이나 Peer-to-Peer 네트워킹이라는 영역에서 폭넓게 발생하는 문제를 해결하기 위해 만들어진 테크놀로지로서 Peer to Peer를 비롯한 분산 Computing들을 위한 Infra Service를 제공하고 있다. JXTA 테크놀로지를 이용하여 제공할 수 있는 여러 서비스 중에 일반 Peer들의 대용량 데이터 전송에서 있을 수 있는 문제점을 해결할 수 있는 서비스를 제안한다. 대용량의 데이터를 여러 서버에서 나누어 받을 수 있도록 하여 Peer-to-Peer 어플리케이션에서 사용자는 찾고자 하는 자료를 검색했을 때 자료의 위치와 함께 제공자의 status와 capability를 monitoring 함으로써 실제 제공할 수 있는 또는 제공하고자 하는 속도와 다운받을 서버와 가져올 데이터의 용량을 결정함으로써 대용량 데이터를 단시간에 효율적으로 주고받을 수 있다.

• Journal of Communications and Networks
• /
• v.14 no.3
• /
• pp.286-295
• /
• 2012

To meet the increased demand of video-on-demand (VoD) services, peer-to-peer (P2P) mesh-based multiple video approaches have been recently proposed, where each peer is able to find a video segment interested without resort to the video server. However, they have not considered the constraint of the server's upload bandwidth and the fairness between upload and download amounts at each peer. In this paper, we propose a novel P2P VoD streaming system, named peer cache adaptation (PECAN) where each peer adjusts its cache capacity adaptively to meet the server's upload bandwidth constraint and achieve the fairness. For doing so, we first propose a new cache replacement algorithm that designs the number of caches for a segment to be proportional to its popularity. Second, we mathematically prove that if the cache capacity of a peer is proportional to its segment request rate, the fairness between upload and download amounts at each peer can be achieved. Third, we propose a method that determines each peer's cache capacity adaptively according to the constraint of the server's upload bandwidth. Against the proposed design objective, some selfish peers may not follow our protocol to increase their payoff. To detect such peers, we design a simple distributed reputation and monitoring system. Through simulations, we show that PECAN meets the server upload bandwidth constraint, and achieves the fairness well at each peer. We finally verify that the control overhead in PECAN caused by the search, reputation, and monitoring systems is very small, which is an important factor for real deployment.

• The Korean Journal of Elementary Counseling
• /
• v.7 no.1
• /
• pp.185-203
• /
• 2008

This study aimed at examining an effect of peer counselor's mentor activity on rejected children's peer relationship in elementary school. To achieve this goal, the following hypothesis was made. Hypothesis I : Peer counselor's mentor activity will improve rejected children's peer relationship. I -1 : Peer counselor's mentor activity will improve rejected children's trust to peer. I -2 : Peer counselor's mentor activity will improve rejected children's respect to peer. To test the hypothesis, after sociometry papers 19 fifth-graders for rejected children groups were selected from four classes at H elementary school in Busan according to Coie & Dodge's(1988) five classified system that is modified to Korean situation by Ahn ie-hwan(2006). Ten rejected students from two classes were labeled as a peer group with a peer counselor and nine rejected students who had similar characteristics from two classes were labeled as an non-peer group without a peer counselor. The peer counselors were decided by obtaining affirmative mentions of rejected students group. Peer counselors participated in the training of peer counselor's skill program and then they had a person to person mentor activity with the rejected children's group that they belonging to. The training consisting of a total of four sessions, 3 times a week, was provided to peer counselors eleven times after school. The peer counselors given the peer counselling training did person to person mentor activity with the peer group's rejected children for a month. The mentor activity, three times a week, following during training was reinforced after school. For peer counselor training, the elementary school children's peer counseling program developed by Lee Sang-hi, Roh Seong-deok and Lee Ji-eun(2001) was used. Hong Ok-soon's(1984) peer relationship test, Moreno's(1934) sociometry tool were used to verify an effect of the peer counselor's mentor activity. For the data analysis, quantitative analysis with sociometry tool and qualitative analysis with social status and social type change were used. To know the difference in pre test and post test peer relationship between experimental group and control group, in quantitative analysis, ANCOVA result was used and qualitative analysis, social status and social type was used. The finding was as followings. First, after peer counselor's mentor activity, there was a significant improvement in rejected children's trust and respect to peer and the whole relationship from the pretest to the post test. Second, peer counselor's mentor activity gave rise to affirmative changes on rejected children's social status and social type. This study concluded that peer counselor's mentor activity would help rejected children's peer relationship to change affirmatively and improve.

• Journal of Institute of Control, Robotics and Systems
• /
• v.14 no.9
• /
• pp.873-880
• /
• 2008

This paper deals with the peer-to-peer data communication to connect each distributed levels of developed unmanned system according to the JAUS. The JAUS is to support the acquisition of unmanned system by providing a mechanism for reducing system life-cycle costs. Each of distributed levels of the JAUS protocol divides into a system, some of subsystems, nodes and components/instances, each of which may be independent or interdependence. We have to distribute each of the levels because high performance is supported in order to create several sub-processor computing data in one processor with high CPU speed performance. To complement such disadvantage, we must think the concept that a distributed processing agrees with separating each of levels from the JAUS protocol. Therefore, each of distributed independent levels send data to another level and then it has to be able to process the received data in other levels. So, peer-to-peer communication has to control a data flow of distributed levels. In this research, we explain each of levels of the JAUS and peer-to-peer communication structure among the levels using our developed unmanned ground vehicle.