• 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 the Institute of Internet, Broadcasting and Communication
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• v.13 no.4
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• pp.29-37
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• 2013

Multiplayer games typically organized based on a client-server(CS) or peer-to-peer(PP) architecture. The CS architecture is not scalable with the number of players due to a large bandwidth requirement at the server. The PP architecture, on the other hand, introduces significant overhead for the players, as each player needs to check the consistency between its local state and the state of all other players. We then propose a method that combines the merits of CS and PP. In this method, players exchange updates with lower priority in a peer-to-peer manner but communicate directly with a central server for the other updates. As a result, the proposed method has a lower network bandwidth requirement than the server of a CS architecture and the server bandwidth bottleneck is removed. For another important issue about multiplayer games, this method always maintains state consistency among players correctly. The performance of this method is evaluated through extensive simulation experiments and analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.11
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• pp.1216-1223
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• 2014

Internet traffic is rapidly increasing due to the spread of personal smart devices and the demand for multimedia contents. When designing a large ship such as cruise, network architecture is also considered which supports various IT services in a maritime environment similar to the ground environment. In this paper, we consider wireless P2P (peer-to-peer) communication for efficient multimedia content sharing and propose novel handover scheme for efficient download service. The proposed handover method shows that it can improve the download symbol rates for handover in a wireless P2P system considering the signal strength and quality of peers as well. The proposed system is expected to provide efficient contents distribution and reliable communication in the ship-area-network (SAN).

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.11
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• pp.471-474
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• 2013

In this paper, we propose a distributed parent peer selection method to construct an efficient peer-to-peer(P2P) network topology by considering the capacity of a peer and the hop distance from a data source to the peer. To achieve this goal, we propose a method to combine the two performance metrics to calculate the probability that a peer becomes a parent peer. Using the probability, we propose a method to select a parent peer stochastically by making use of the state information of the neighboring peers that each peer maintains. Through simulation studies, we show that the proposed method drives high capacity peers to support more children peers and makes the diameter of the P2P network shorter than the other methods.

• Journal of Families and Better Life
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• v.23 no.1 s.73
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• pp.99-111
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• 2005

The purpose of this study was to discriminate important variables among general self-efficacy, peer attachment, and parent-child communication that could predict internalizing problems(anxiety, depression) of Korean children of divorce. The participants were 101 children aged from 10 to 13. They completed questionnaires and discriminant function analyses were performed. The results showed that (a) the discriminant function derived from 3 variables was effective in classifying high, moderate, and low group of children's anxiety and depression, (b) parent-child communication plays a key role in predicting anxiety and general self-efficacy plays a key role in predicting depression of Korean children of divorce, (c) but peer attachment plays a significant role only to predict depression. This means that anxiety and depression of Korean children of divorce result from different kind of interactions among children's important contexts.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.568-570
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• 2013

NFC represents the 2nd generation of the proximity contact-less technology, which beyond the RFID, supports peer-to-peer communication, and enables consumer access to aggregated services, anytime, anywhere, with any type of consumer stationary and mobile devices. NFC is a short range device wireless technology designed to exchange data, initiate connections with other wireless networks and act as a secured smart key for access to services such as cashless payment, ticketing, on-line entertainment and access control. In this paper, the NFC services for social networking applications are studied, and the signal flow of SNS application based on NFC P2P for smart devices and server model is proposed.

• Annual Conference of KIPS
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• 2009.04a
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• pp.780-783
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• 2009

기존 정보보호 콘텐츠에 대한 공유는 웹이나 메일 등을 통하여 수동적으로 배포되고, 운영관리자의 판단을 거친 후 보안등급에 맞게 제공되었다. 하지만 사이버 공간의 침해사고는 급속히 확산되어 끊임없이 보안 환경을 위협하는데 그에 대한 확산방지 대응은 즉각적이지 못한 문제점을 가지고 있다. 이러한 침해사고의 빠른 확산을 방지하기 위해서는 실시간 보안 콘텐츠 공유를 통해 각 시스템에서 콘텐츠의 추가 및 변경이 발생할 경우 자동으로 인지 또는 배포할 수 있는 정보보호 시스템을 개발할 필요가 있다. 따라서 본 논문에서는 보안등급에 따른 가상 정보공유 그룹을 구성하기 위해 P2P방식인 JXTA 플랫폼을 적용하였다. 또한 JXTA CMS의 확장을 통해 정보공유 시스템 간 연동할 수 있는 실시간 보안 콘텐츠 공유 시스템을 설계하였다. 이를 통하여 지리적으로 분산된 정보보호 콘텐츠를 실시간 자동인지와 보안등급에 맞는 실시간 공유 방식으로 배포하는 정보보호 시스템을 구현하고자 한다.

• Journal of the Korean Society of School Health
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• v.29 no.3
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• pp.256-266
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• 2016

Purpose: This study was to compare and to examine the factors related to risk behaviors of adolescents living in small and medium-sized cities and in rural areas. Methods: The subjects were 545 adolescents (295 from small and medium-sized cities and 250 from rural areas). The data was analyzed by descriptive statistics, Pearson corelation coefficients, and multiple regression with IBM SPSS 19.0 program. Results: The factors influencing the risk behaviors of adolescents in small- medium cities were school, peer risk factors and community risk factors, self- control among protective factors, positive communication with parents, positive peer associations, these variables explained 42.0%. The most important variable explaining the risk behaviors of adolescents in small- medium cities was positive communication with parents, followed by community risk factors, peer risk factors, positive peer relationships, school and self-control. The factors affecting the risk behaviors of rural adolescents were school, personal risk factor, peer risk factor, self- control factor, which explained 38.5% of the risk behaviors of adolescents in rural areas. Among them, the most important variable explaining risk behaviors was personal risk factors, followed by peer risk factors, school, and self-control. Conclusion: These finding suggest a need to develop a strategy to improve positive communication with parents for adolescents living in small- medium cities and a strategy to reduce personal risk factors and peer risk factors for rural adolescents.

• Journal of Digital Convergence
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• v.15 no.3
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• pp.365-373
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• 2017

This research aims to verify the moderating effect of sports activity satisfaction in the relationship between adolescents' communication skills and positive self-concept within peer group. To achieve this purpose, this study extracted 250 samples from five boys high schools in Gyeonggi-do, and used survey of 232 students for actual analysis excluding the surveys with unfaithful answer or double entry. Questionnaire was used as a tool for collecting data and conducted frequency analysis, correlation analysis and moderator regression analysis to analyze the collected data. This study drew the following results. It was identified that sub-factors of sports activity satisfaction as social, physical, environmental and educational satisfaction have the moderating effect in the relationship between adolescents' communication skills and social self-concept with peer group. In other words, communication skills within adolescents' peer group play an important role in improving positive self-concept, but when sports activity satisfaction put as a moderating variable, adolescents' positive self-concept would be more improved.

• Journal of the Korea Society of Computer and Information
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• v.23 no.11
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• pp.175-183
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• 2018

In modern society, the optimal physical environment is constantly changing due to IT development, and it is provided with convenience. In this age environment, the children are growing up thinking that the value of community consciousness through relationship with others is not important in the social reality in which various ways and environments that can be done by themselves are succeeding. No matter how rapidly the world changes, a diverse learning environment is needed that establishes desirable human relationships and recognizes community consciousness and values. The purpose of this study was to investigate the effects of general children(elementary school 4th, 5th, and 6th graders) on the communication and peer relationship of the children participating in the archery experiential learning program, to emphasize the importance of physical activity programs, and also by analyzing the relationship between communication and improvement of peer relationship and to understand the effect of the archery experiential training learning which is one of exercise program. In order to verify the research problems, 30 experimental group and 30 comparative group were composed of 4th, 5th, and 6th grade elementary schools in Gwangsan-gu, Gwangju metropolitan city. The experiment group was participated in the archery experiential learning program for a total of 10 sessions, once a week for 60 minutes, and conducted a questionnaire survey. In this study, we examined the effect of archery experiential learning program on improving children 's communication and peer relationship ability. Thus, it showed that archery experiential learning program can be one of the important educational methods to promote the healthy character and development of children.