• 한국통신학회논문지
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• 제35권8B호
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• pp.1197-1203
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• 2010

최근 파일 공유를 위해 널리 사용되는 BitTorrent의 강점은 BitTorrent의 핵심 메커니즘인 peer 선택 기법에 기인한다. Peer 선택 기법은 해당 호스트가 업로드 할 peer를 선택하는 것인데, 이 때 자신에게 각 peer가 업로드한 비율을 비교해서 가장 많이 업로드한 peer들에게 업로드를 하게 된다. 그런데 BitTorrent에서는 업로드할 peer의 개수 (즉, unchoked peer 개수)를 4개로 고정하고 있다. 하지만 peer들의 개수나 다운로드 속도, 업로드 속도와 같은 공유집단 (즉, swarm)의 특성은 계속 변하기 때문에 unchoked peer 개수를 고정하는 것은 효율적이지 않다. 본 논문에서는 BitTorrent에서 unchoked peer 개수가 고정된 4개가 아니라 변할 때 전체 시스템 성능에 어떠한 영향이 끼치는지 분석한다. 분석을 위해 본 논문에서는 서울대학교 캠퍼스 망에 테스트베드를 설치하였고, 실제로 널리 사용되는 오픈 소스 BitTorrent 클라이언트를 수정해서 사용하였다. 테스트베드에서의 다양한 실험을 통해 BitTorrent의 성능이 unchoke 개수에 따라 달라지게 되는 것을 보였고, 이에 따라 swarm의 상황을 고려해서 unchoke개수를 적절하게 조절하는 메커니즘이 필요하다는 것을 보였다.

• 한국시뮬레이션학회논문지
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• 제15권4호
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• pp.97-105
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• 2006

인터넷 상에 저장된 콘텐츠를 3세대 통신 서비스를 이용해 내려 받으면 편리하지만, 자료의 양에 비례하여 통신료를 부과하는 경우 비용 면에서 부담스러울 수 있다. 본 논문은 peer라고 하는 이동단말기들이 협력하여 콘텐츠를 내려 받는데 지불하는 3G 통신비용을 줄이고자 콘텐츠의 지정된 일부분만을 유료인 3G 채널을 통해 내려 받고, 각 peer들은 자신이 내려 받은 부분을 다른 모든 peer들이 내려 받은 부분과 무료인 애드 혹 네트워크를 통해 교환 후 각 부분을 재구성하여 전체 콘텐츠를 생성한다. 본 논문은 per-peer 방식의 배분 방법을 주로 소개하며, 본 방법을 이와 유사한 방법인 per-packet 배분 방법과 성능을 비교한다. 시뮬레이션 결과로 볼 때, per-peer 방법이 per-packet 방법보다 우수하며, 두 방법 모두 10개의 peer가 참여하였을 때 약 90% 정도의 통신비용을 절감할 수 있다.

• 가정과삶의질연구
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• 제22권1호
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• pp.45-54
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• 2004

To examine group differences among four groups divided by asgression/victimization status, 655 4th graders living in Seoul reported their perceptions of peer aggression, peer victimization, personality traits, parent attachment, and their parents' marital conflict. Peers of the subjects also reported their perceptions of peer aggression and peer victimization. Based on the scores of peer aggression and peer victimization, each child was classified into one of the four groups: nonvictimized aggressors, aggressive victims, passive victims, and normative contrasts. For boys, nonvictimized aggressors were more sociable/active than both aggressive and passive victims. Aggressive victims were more shy/emotional than nonvictimized aggressors and normative contrasts, and were exposed to the highest parental marital conflict. For girls, passive victims were the least sociable/active among the four groups, and showed lower attachment to fathers than normative contrasts. Both aggressive and passive victims were more shy/emotional than nonvictimized aggressors and normative contrasts, and normative contrasts were exposed to the lowest parental marital conflict.

• 아동학회지
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• 제38권1호
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• pp.217-231
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• 2017

Objective: The purpose of this study was to examine the influence of affective and cognitive empathy, and peer competence on behavioral problems among young children. Methods: The participants were 224 4- to 5-year-olds attending daycare centers in Gyeonggi-do. Children's empathy, peer competence, and behavioral problems were reported by their teachers. The collected data were analyzed using simple regression and three-step hierarchical multiple regression analyses. Results: The results showed that children who exhibited low affective empathy scored higher on peer acceptance and behavioral problems than children who had high affective empathy. This pattern of results was similarly found with cognitive empathy. Additionally, the effect of children's affective empathy on behavioral problems was fully mediated by peer competence, whereas the effect of children's cognitive empathy on behavioral problems was partially mediated by peer competence. Conclusion: These results suggest the need for peer-competence training based on affective empathy and training for both peer competence and cognitive empathy in reducing behavioral problems among young children.

• 대한가정학회지
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• 제48권10호
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• pp.25-35
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• 2010

본 연구는 또래 괴롭힘 피해와 학교적응의 관계에서 자아 및 또래 지각의 매개효과를 검증하고자 하였다. 연구대상은 초등학교 5, 6학년 남녀 아동 521명이다. 또래 지명법을 사용하여 또래 괴롭힘의 피해가 측정되었고 자기 보고법을 사용하여 자아 및 또래 지각과 학교 회피가 측정되었다. 연구결과를 보면, 자아 및 또래 지각은 또래 괴롭힘 피해와 학교적응의 관계에서 완전 매개 효과가 있었으며, 반면에 또래 괴롭힘 피해는 학업 성취에 직접적인 영향을 미치는 것으로 나타났다.

• 아동학회지
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• 제31권3호
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• pp.17-32
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• 2010

In this study, I examined the direct or indirect paths among the intra-personal factors as well as extra-personal factors affecting on children's peer competence. Subjects were 514 5-year-old children, their mothers, teachers. The teachers rated each children using Peer Competence Scale (Park, 2001) and completed emotion regulation and Student-Teacher Relationship Scale. The mothers responded to a questionnaire, including Parental Involvement Checklist (Cohen, 1989), parenting behaviors, and Children's Temperament. The data were used for path analysis with Amos 6.0 program. Results of this study were : (1) Children's temperament have an influence on children's peer competence through children's emotion regulation via mothers' parenting behaviors. (2) Children's temperament have an influence on children's peer competence through teacher-child relationship. (3) Mothers' parenting behaviors have an influence on children's peer Competence through mothers' management strategies of peer relations.

• 한국멀티미디어학회논문지
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• 제7권7호
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• pp.922-933
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• 2004

최근 분산 시스템이나 협업 시스템을 위한 피어 투 피어(Peer-to-Peer) 네트워크에 대한 연구가 진행되고 있으며 암호학 분야에서는 pairing을 이용한 ID 기반의 공개키 암호 기법에 대한 연구가 활발히 이루어지고 있다. 본 논문에서는 동적 피어 그룹(Dynamic Peer Group, DPG) 멤버간의 안전한 그룹통신을 위한 ID 기반의 그룹키 관리 기법을 제안한다. 각 멤버들은 Private Key Generator(PKG)로부터 자신의 ID에 대한 공개키/개인키쌍을 발급 받으나, 그룹키를 관리하기 위한 중앙 관리개체를 이용하지 않고 멤버들간의 협력(collaboration)을 통해 자발적으로 그룹키를 관리함으로써 중앙 관리개체의 오류에 대한 문제(single-point of failure)를 예방할 수 있다. 그리고 동적 피어 그룹의 성질을 고려하여 멤버의 참여와 탈퇴에 대한 그룹키의 비밀성을 제공한다.

• 영어어문교육
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• 제18권3호
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• pp.149-174
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• 2012

This research aims at exploring what Korean teachers of English need for their effective professional development, particularly from the perspectives of peer trainers who are school teachers as well as teacher trainers. The research is based on an assumption that despite the critical roles of peer trainers in the changing process of English education, very little attention has been paid to listening to their voices. Having an awareness of the meaningfulness of their voices in teacher education, the researcher collected and analyzed the data, employing a questionnaire responded by 32 peer trainers and in-depth group interview with 6 peer trainers who responded the questionnaire. The research findings suggest that the majority of peer trainers believe that the priority should be put on teaching practice rather than language competence for Korean English language teacher development. It has been found that they believe that teacher learning within the workplace with some support from outside experts is the most effective way of making classroom change possible and keeping teachers' professional development sustainable. Finally, the research suggests school-based professional development as an alternative strategy to satisfy their needs on effective and sustainable professional development.

• 아동학회지
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• 제19권1호
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• pp.43-53
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• 1998

This study investigated the relations among maternal cognition, maternal supervisory/monitoring behaviors, and their children's peer competence. The participants were 40 kindergarten children and their mothers. The mothers completed a questionnaire concerning maternal beliefs about children's social skills. Also their supervisory/monitoring behaviors were observed in the context of child-peer interactions. Children's peer competence was measured using a sociometric status measure and a peer acceptance rating scale. Maternal beliefs were related both to the quantity/quality of maternal supervisory/monitoring behaviors and to children's peer competence. Maternal supervisory/monitoring behaviors were also related to children's actual peer competence.

• 한국지구과학회지
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• 제25권3호
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• pp.129-141
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• 2004

A peer assessment method was implemented as part of an action research project where the primary goal was to create constructivist science classrooms. Student reflective writings, which had been created in the process of action research, were analyzed to examine the perceptions of the students concerning the peer assessment method employed in their earth science classrooms. Five perception categories and thirteen statements were developed from the student writings. These indicated that the students appreciated the positive nature of peer assessment and the effects of it as an alternative method for promoting learning. It was also revealed, however, that some students displayed inappropriate behaviors toward peer assessment which led to negative perceptions of the new assessment method. Implications for future use of peer assessment in science classrooms are discussed. Limitations founded in the present study as well as possible solutions are provided.