• Proceedings of the Korea Information Processing Society Conference
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• 2009.04a
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• pp.1314-1316
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• 2009

최근 모바일 단말의 사용과 그에 관련된 제품의 개발이 급증하고 있는 관계로 이와 관련된 많은 Peer-to-Peer (P2P) 연구들이 진행 중이다. 특히, Mobile Ad-Hoc 네트워킹 환경에서의 P2P 방식에 대한 연구 또한 활발히 진행되고 있다. 하지만, Flooding 방식의 메시지 전송은, 파일 탐색 시 Query 메시지 가 기하급수 적으로 증가할 수 있다. 이러한 메시지 전송은 센서 네트워크에서는 전력의 급격한 소모를 가져와 네트워크의 유지를 할 수 없게 하는 등의 오버헤드를 발생시킨다. 본 논문에서는 이러한 P2P 파일 검색에서의 메시지 전송수를 줄이기 위해 Mobile Ad-Hoc Network 환경에서 Peer를 Parent Peer(PPR)와 Child Peer(CPR)로 구분화하여 그룹화를 시키고 그룹을 Peer로 둔 P2P 네트워크를 구성하였다. 또한, 그룹 안에서 발생하는 CPR들의 가입과 탈퇴를 관리하여 오버헤드 발생을 줄이는 방법을 제안한다.

• Korean Journal of Human Ecology
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• v.13 no.5
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• pp.659-672
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• 2004

This study examines different individual, family, and school environmental variables that affect victimization by peer aggression among adolescents. The sample consists of 868 seventh and eighth graders. Statistics and method for data analysis include Cronbach's alpha, percentage, means, standard deviation, Pearson correlation, multiple regression, and hierarchical regression. The major findings of this study are as follows: First, adolescents, both withdrawn and aggressive, have lower achievement in school work. Boys experience more direct victimization by peer aggression. Adolescents, especially boys, often experience indirect victimization by peer aggression, when they become withdrawn, own lower self-esteem, and have lower achievement in school work. Second, adolescents have more direct victimization by peer aggression when their parents are negligent of them. Also, adolescents seem exposed to indirect victimization by peer aggression when they receive more physical and emotional abuse and negligence from their parents. Third, adolescents experience more victimization by peer aggression-whether it's direct or indirect, when they cannot get adjusted to peer relations and get teachers' supervision. Fourth, as to direct victimization by peer aggression, withdrawal, one of the individual variables, is the most reliable prediction followed by gender, negligence, adaptability in peer relations, aggression, and teacher's supervision in sequence. For indirect victimization by peer aggression, withdrawal is the most reliable prediction followed by adaptability in peer relations, gender, physical and emotional abuse, and negligence in sequence.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.11-19
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• 2004

P2P network environments provide users with direct data transmission and sharing facilities and those environments can be classified into hybrid P2P network environments and pure P2P network environments according to the arbitration mechanism among the peers in the network. In hybrid P2P network environments, there exists a server that maintains index information for the data to be shared and network isolation does not occur because every peer always keeps connection to the server. In pure P2P network environments, however, each peer directly connects to another peer and gets services without server intervention, and so, network isolation can occur when the mediating peer fails to work. In this paper. we propose a scheme for each peer to keep connection to other peers continuously by maintaining IP addresses of its neighbor peers and connecting to the peers when the mediating peer fails to work. Although the P2P application that uses our proposed framework should obtain one or more IP addresses of the neighbor peers manually, after instantiation, the application can do its job while maintaining connection to the network continuously and automatically. To evaluate our proposed scheme, we measured and analyzed the time for a peer to reconnect to the network when the mediating peer fails and the network isolation occurs.

• The KIPS Transactions:PartA
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• v.13A no.6 s.103
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• pp.501-510
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• 2006

The self-organizing super peer ring P2P search scheme improves search performance of the existing unstructured peer-to-peer systems, in which super peers with high capacity constitute a ring structure and all peer in the system utilize the ring for publishing or querying their keys. In this paper, we further improves the performance of the self-organizing ring by adaptively changing its super peer ratio according to the status of the entire system. By using PSO, the optimized super peer ratio can be maintained within the system. Through simulations, we show that our self-organizing super peer ring optimized by PSO outperforms not only the fixed super peer ring but also the self-organizing super ring with fixed ratio in the aspect of query success rate.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.10
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• pp.752-760
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• 2009

Emerging peer-to-peer systems benefit from the large amount of resources provided by many peers. However, many peer-to-peer systems or applications suffer from malicious peers and it is not guaranteed that peers are always online. Micropayment systems are accounting and charging mechanism for buying services, so we can apply them to solve these problems. In the past the majority of micropayment system uses a centralized broker but the problem with most existing micropayment system is a heavy load on the broker. For instance, when an owner of the coin is offline, the broker delegates the owner and handles payment messages. It occurs frequently because of characteristic of peer-to-peer system and is another load of the broker. In this paper we introduce DPay, a peer-to-peer micropayment system that uses distributed hash table (DHT) for storing encrypted payment messages and increases scalability and reduces the load of broker by removing downtime protocol. We show the idea of real-time double spending detection in DPay and report the results of several evaluations in order to compare DPay and other payment scheme. In simulation result, the load of broker in DPay is reduced by 30% on average of other previous payment scheme. We expect that DPay can apply various peer-to-peer systems because it provides a real-time double spending detection and stores more secure payment messages.

• Korean Journal of Child Studies
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• v.25 no.2
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• pp.93-108
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• 2004

This study investigated personality and environmental variables influencing peer bullying by sex and by differences between bullies, victims, bully-victims, and normal children. Findings were that the proportion of the total sample involved in peer bullying was 47.88%. Of the bullying children, 38.15% were bully-victims, followed by victims and bullies. The bullying of both boys and girls was influenced by exposure to violence, delinquent friends, and peer support. Bullies had higher levels of aggression and exposure to violence than normal children and higher levels of peer support than victims. Victims had higher levels of delinquent friends and exposure to violence than normal children. Bully-victims showed higher levels of aggression, immaturity, delinquent friends, exposure to violence and lower levels of peer support than normal children.

• Human Ecology Research
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• v.60 no.4
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• pp.497-505
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• 2022

This study aims to examine the mediating role of peer attachment between affective school environments and the problematic behaviors of children using data from the Panel Study on Korean Children 10th wave (2017). Descriptive statistics, reliability analysis, correlation analysis, multiple regression analysis, Sobel test, and bootstrapping versification were performed using SPSS 28.0 and Process Macro 28.0. The results indicate that controlled and rigid school environments were negatively associated with peer attachment and positively associated with both internal and external behavior problems. Furthermore, peer attachment was negatively associated with both internal and external behavioral problems. Peer attachment completely mediated the link between affective school environments and internal behavioral problems, and partially mediated the link between affective school environments and external behavioral problems. These results show the important role of supportive and democratic school environments regarding peer attachment.

• Journal of the Korean Home Economics Association
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• v.40 no.1
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• pp.23-35
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• 2002

The purpose of this study was to examine the personal, familial, school and peer characteristics related to adolescents' runaway drive. The 259 subjects were selected from high school student in the city of Daegu. The major findings of study were as follows: 1. In respect of personal characteristics, the more runaway drive was, the lower self-esteem was and the higher anxiety, depression, and impulsive mind was. 2. In respect of familial characteristics, the more runway drive was, the lower family cohesion and family adaptation was and the higher the degree of parents' rejection was. And the higher runway drive was, the higher degree of child abuse and interparental conflict. 3. In respect of school characteristics, the more runway drive was, the lower school adaptation was. 4. In respect of peer characteristics, the more runway drive was, the higher degree of delinquency of peer.

• Korean Journal of Childcare and Education
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• v.18 no.6
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• pp.127-144
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• 2022

Objective: The purpose of this study was to examine the relative influences of senior elementary school children's communication level with their fathers and peer competence on their happiness. Methods: The subjects of this study were 310 fifth and sixth grade students attending elementary school in Jeollanam-do. They responded to the level of communication with their fathers, peer competence, and happiness. For the data, t-test, Pearson's correlation analysis, and hierarchical regression analysis were performed. Results: First, there were some statistically significant differences according to gender differences in self-esteem and a sub-factor of happiness and the differences according to grades in open-type communication and problem-type communication. Second, it was found that children's happiness was highly correlated with communication with their fathers and peer competence. Third, the factors having the greatest relative influence on overall happiness were in the order of peer competence, open-type communication, problem-type communication, and gender. The variables influencing and the order of relative influence differed according to sub-factors of happiness. Conclusion/Implications: The present study revealed that peer competence has a significant impact on children's happiness. The results of this study suggest that research and development of convergent programs that can improve communication with fathers, peer competence, and children's happiness are necessary.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.697-699
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• 2004

최근 MANET(Mobile Ad-hoc Networks)에서의 P2P 응용을 이용한 서비스 개발이 활발히 진행 중이다. 이와 함께 에드혹 환경에서의 적합한 P2P 모델에 관한 연구로 기존 P2P 모델인 Gnutella, DHT등을 에드혹에 적용한 연구 역시 활발히 이루어지고 있다. 본 논문에서는 on-demand 방식의 에드혹 라우팅 프로토콜인 AODV(Ad-hoc On-Demand Distance Vector)상에서, 대표적인 P2P 응용인 Gnutella의 동작 과정을 통해 P2P 응용이 갖는 문제점을 분석하고, P2P 응용의 검색과정에서 발생하는 오버헤드를 줄이기 위한 방안을 제안한다. 그리고 위의 연구 결과를 바탕으로 현재 IPv6 AODV상에서 MANET을 위한 응용인 DiPP(Fully Distributed Peer-to-Peer)시스템을 구현한다. DiPP 시스템은 MANET상에서의 메신저와 파일공유를 위한 기능을 위해 동작한다.