• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.51-60
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• 2011

In this paper, we propose a P4P based P2P system for live multimedia streaming services. In order to satisfy the strict requirement of delay in live multimedia streaming, in the proposed scheme, the P4P server of network provider provides the network status information related to delay and congestion links to P2P system in addition to the information to optimize the network resource utilization. The P2P system server, then, makes the peering suggestion based on the information from the network server. Also, we propose a playback synchronization mechanism that enable each peer to start the playback within the limited variation from the playback positions of source peer. Through the simulation results, it is shown that the proposed scheme not only deals with the original objective of the P4P framework, i.e., effective network utilization, but also the live multimedia streaming requirements. It enhances the playback continuity, and reduces the playback start-up latency and the control overhead. In addition, the proposed scheme reduces the variation in playback positions of the peers.

• Annual Conference of KIPS
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• 2013.05a
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• pp.411-412
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• 2013

유비쿼터스 기반 기술은 기존의 다양한 장치 및 서비스를 기반으로 발전되고 있다. 분산 시스템의 효율적인 활용에 쓰이는 P2P 기술은 유무선 네트워크로 연결된 환경에서 보유한 자원을 효율적으로 공유하는 측면에서 활용되고 있다. 유비쿼터스 환경에서 무수히 많은 센서를 기반으로 USN 기반을 구축할 수 있는데, 센서 데이터 자체의 정보양은 일반적인 P2P 기술에서 전송되는 정보양에 비하면 매우 적다. 그러나 센서 자체가 일반 P2P 네트워크의 단독 노드로써의 역할을 한다고 보았을 때 컴퓨팅 능력은 매우 미미한 것이다. 이러한 환경에서 하나의 노드에서 목적지 센서 노드로의 빠른 데이터 전송이 요구됨으로 그와 관련된 연구가 필요하다. P2P 시스템의 고유의 특성상 자원 검색, 전송, 재전송 작업이 이뤄질 때마다 네트워크 트래픽이 과다하게 발생되는 단점을 갖고 있는데, USN으로 한정된 환경에서는 이러한 고유의 특징이 시스템의 중요 문제로 인식되지 않는다. 따라서 이를 가정치로 두고 효과적인 데이터 전송을 위한 라우팅 알고리즘을 제안한다.

• Journal of information and communication convergence engineering
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• v.13 no.2
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• pp.86-96
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• 2015

In mobile communication, mobile services [MSs] (e.g., phone calls, short/multimedia messages, and Internet data) incur a cost to both mobile users (MUs) and mobile service providers (MSPs). The proposed model MobPrice consists of dynamic data pricing schemes for mobile communication in order to achieve optimal usage of MSs at minimal prices. MobPrice inspires MUs to subscribe MSs with flexibility of data sharing and intra-peer exchanges, thereby reducing overall cost. The main contributions of MobPrice are three-fold. First, it proposes a novel k-level data-pricing (kDP) scheme for MSs. Second, it extends the kDP scheme with the notion of service-sharing-based pricing schemes to a collaborative peer-to-peer data-pricing (pDP) scheme and a cluster-based data-pricing (cDP) scheme to incorporate the notion of 'cluster' (made up of two or more MUs) in mobile communication. Third, our performance study shows that the proposed schemes are indeed effective in maximizing MS subscriptions and minimizing MS's price/user.

• Journal of Internet Computing and Services
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• v.12 no.4
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• pp.157-172
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• 2011

The latest active studies on distributed OLAP to adopt a distributed environment are mainly focused on DHT P2P OLAP and Grid OLAP. However, these approaches have its weak points, the P2P OLAP has limitations to multidimensional range queries in the cloud computing environment due to the nature of structured P2P. On the other hand, the Grid OLAP has no regard for adjacency and time series. It focused on its own sub set lookup algorithm. To overcome the above limits, this paper proposes an efficient central managed P2P approach for a cloud computing environment. When a multi-level hybrid P2P method is combined with an index load distribution scheme, the performance of a multi-dimensional range query is enhanced. The proposed scheme makes the OLAP query results of a user to be able to reused by other users' volatile cube search. For this purpose, this paper examines the combination of an aggregation cube hierarchy tree, a quad-tree, and an interval-tree as an efficient index structure. As a result, the proposed cloud P2P OLAP scheme can manage the adjacency and time series factor of an OLAP query. The performance of the proposed scheme is analyzed by a series of experiments to identify its various characteristics.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10c
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• pp.19-21
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• 2003

P2P(peer­to­peer) 방식의 통신 모델의 강점은, 기존의 Server­Client 모델에 비해 Server에 대한 의존도가 낮고, 중앙 집중의 제어를 받지 않는다는 것이다. 그러나, 현재 사용되고 있는 일반적인 P2P 모델들은 서비스의 성격과 시스템 환경이 달라, 서로 호환되지 않는 문제가 있다. 썬 마이크로시스템사에서 제안한 JXTA는 프로그래밍언어와 플랫폼에 독립적으로 개발 가능한 P2P 모델로서 다양한 환경에서 적용이 가능하다. 그러나 이러한 JXTA를 무선환경에서 원활하게 적용하기에는 J2ME Device의 제한된 자원으로는 한계가 있다. 본 논문에서는 J2ME Device를 위해 JXTA기반의 Relay를 사용하여 무선환경에서 유연하게 적용되는 P2P 서비스를 구현하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.6
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• pp.95-102
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• 2012

In this paper, we propose a method that can construct efficiently a P2P overlay multicast network composed of many heterogeneous peers in communication bandwidth, processing power and a storage size by selecting a peer in a distributed fashion using an ant-colony theory that is one of the computational intelligence methods. The proposed method considers not only the capacity of a peer but also the number of children peers supported by the peer and the hop distance between a multicast source and the peer when selecting a parent peer of a newly joining node. Thus, an P2P multicast overlay network is constructed efficiently in that the distances between a multicast source and peers are maintained small. In addition, the proposed method works in a distributed fashion in that peers use their local information to find a parent node. Thus, compared to a centralized method where a centralized server maintains and controls the overlay construction process, the proposed method scales well. Through simulations, we show that, by making a few high capacity peers support a lot of low capacity peers, the proposed method can maintain the size of overlay network small even there are a few thousands of peers in the network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.579-582
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• 2004

File share system in client/server method requires server of High performance and capacity and this server is very expensive and management is complex and is been influenced much to flatform. Also, extension of correct memory or hard drive etc. causes a lot of expenses to server. While, may minimise human who happen by buying high-capacity server by dispersing file public ownership way unuse expensive server in client/serve. way who put up files in PC(client) to a sewer and manage files and make use of only client computers because public ownership of data and government official in P2P(peer to peer) environment, waste of material resources. Many people are interested to P2P by such reason, researches that use P2P to connection field to be Moba that have Gakgwangbatgo current are gone vigorously.

• Journal of Digital Contents Society
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• v.10 no.2
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• pp.239-247
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• 2009

In simple topology in network system, query should be delivered to all linked peers for query processing. This causes waste of transmission band width and throughput of each peer. To overcome this, as well as query processing strategy, efficient routing technique to deliver query to proper peer is needed. For efficient routing, clustering of peers in P2P networks is important. Clustering of P2P network bases on that combines peers that have similar characteristics in same cluster reduces quantity of message in network than assign peer for cluster randomly. In this paper, we propose clustering techniques for ontology based P2P query processing. Similarity measure point, cluster index structure, and query processing steps in ontology based P2P cluster environment are proposed.

• Journal of the Korea Convergence Society
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• v.10 no.12
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• pp.453-463
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• 2019

The purpose of study was the non-equivalent control group pretest-posttest design to test the effect of self-directed nursing practice based peer-tutoring of same sophomore, on the level of confidence, performance and self-efficacy of core nursing skills in nursing students. The subjects were 68 nursing students in K City from May 1^th to June 12^th in 2019. The participants were shared into the peer tutoring practice group (experimental group, n=34) and the lecturer guided practice group (control group, n=34). The results of study, the experimental group scored significantly higher on the foley catheterization performance (t=11.60, p<.001), confidence (t=4.123, p<.001) and wearing protection equipment performance (t=5.91, p<.001), confidence (t=4.24, p<.001) and enema performance (t=2.82, p=.008), confidence (t=2.09, p=.044) and self-efficacy (t=4.52, p<.001) than control group. Therefore, the results justified that self-directed nursing practice based peer-tutoring could be effective in improving the performance, confidence and self-efficacy of core nursing skills in nursing students. Based on this, I suggest the study that examines the effects of peer-tutoring by applying it to various majors.

• The Journal of the Korea Contents Association
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• v.15 no.12
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• pp.35-49
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• 2015

Recently, with the development of wireless communication technologies and mobile equipments, various studies on mobile P2P networks have been conducted. In this paper, we propose an advertisement dissemination method considering peer's mobilities and preferences in mobile P2P networks. The proposed scheme generates a peer's preference through the analysis of users' activities to disseminate advertisements with user preferences. To reduce duplicated advertising messages and improve reception ratio, the priority of advertisement re-dissemination is determined according to peer's preferences, mobilities, and advertisement reception ratio. We improve the participation rate of the advertisement dissemination of mobile peers using the incentive mechanism in mobile P2P networks. To show the superiority of the proposed scheme, we compare it with the existing scheme in terms of the number of messages and accuracy.