• Journal of KIISE:Computing Practices and Letters
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• v.7 no.6
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• pp.630-640
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• 2001

In this paper, we describe the design and implementation of ObjectPeerWork, which is a framework for the development of shared object model-based P2P(Peer-to-Peer) applications. The shared object model can prevent the computing power decrease on the way of resource management by incorporating the resource management function into resources themselves, and raise reliability on shared resources by improving the security problems. Also this model assures expandability by means of distributed component-based request broker manager and module container. The ObjectPeerWork based on this shared object model is a framework which makes the implementation of the enterprise information system possible, and makes distribution of the computing power and efficient resource management possible by improving the weakness in the general P2P model.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.4
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• pp.449-456
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• 1999

본 논문은 C++에 분산 객체 프로그래밍 기능을 추가한 D++ 언어를 제안한다. 대등관계 복제객체 모델을 지원하는 D++는 분산 클래스의 정의, 멤버 함수의 일치성 제어 정의 기능, 그리고 영구 객체 이름에 기반한 분산 객체를 정의할 수 있는 언어 구조를 제공한다. D++ 프로그램에서 새로이 생성되는 분산 객체는 생성 시에 제공되는 객체의 영구 이름과 동일한 영구 이름을 갖는 분산 객체가 존재할 경우 해당 객체들과 복제 관계를 유지함으로써 정보를 공유한다. 각 복제 객체들은 서로 간에 대등한 관계를 가지며, 멤버 함수 정의 시에 기술되는 특성에 따라 일치성이 유지된다. 이 같은 D++의 분산 객체 모델은 실시간 그룹웨어의 기본 요구 사항인 분산 환경에서의 정보 공유 및 사건 공지 기능을 자연스럽게 해결해 주기 때문에 실시간 그룹웨어의 개발을 효율적으로 지원할 수 있을 것으로 기대한다. Abstract This paper proposes D++ programming language that is an extension of C++ for distributed object oriented programming. The D++, which supports peer-to-peer object model, provides new language constructs for the definition of distributed classes, the definition of the consistency control of the member function and the definition of distributed object variables with the persistent name. In D++, when the persistent name of a newly created distributed object is same as that of an existing distributed object, the new distributed object replicates object state of the existing distributed object and thus they share the object state. The replicas have peer relation and the consistency among them is maintained according to the characteristic described on the definition of designated member functions. It is expected that D++ language increases efficiency in development of real-time groupware because the distributed object model of D++ naturally supports the information sharing and event notification that are the basic functions required when building real-time groupware.

• Journal of the Korean Home Economics Association
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• v.42 no.4
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• pp.29-43
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• 2004

The purpose of the current study was to investigate peer conflict situations and age differences in preschoolers' emotional behavior of happiness, sadness, and anger. Participants were twenty-two 3-year-olds and twenty 5-year-olds, and each pair of the same age interacted in two standardized conflict situations: object possession conflict and behavioural/interpersonal conflict. Participants' emotional behaviors of happiness, sadness, and anger were obsewationally coded through facial expression, verbal intonation, gesture, and physical contact. Preschoolers expressed more sadness and anger emotional behavior in object possession conflict than in behavioural/interpersonal conflict. In object possession conflict, 3-year-olds expressed more anger emotional behavior than 5-year-olds did. In behavioural/interpersonal conflict,5-year-olds expressed more happiness emotional behavior than 3-year-olds did.

• Proceedings of the Korean Information Science Society Conference
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• 2003.04d
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• pp.289-291
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• 2003

Peer-to-Peer Network에서의 object위치 정보의 배치 및 라우팅 방법인 Chord시스템은 node ID와 object ID생성에 있어서 SHA-1과 같은 해쉬 함수를 사용한다. Chord object위치 정보 관리에 있어서 해쉬에 의해 저절로 load-balancing을 기대하나 실험에 의하면 노드별 load에는 상당한 편차가 있음이 나타난다. 그러므로 이 논문에서는 각 node간 협력을 통하여 보다 효과적인 load-balancing을 제공하는 CLCS 기법을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.553-555
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• 2001

본 논문에서는 분산 가상 환경을 기반으로 한 원격교육시스템을 제안한다. 기존에 제안되었던 대부분의 원격교육시스템 들은 클라이언트/서버 구조를 택함으로써 시스템의 확장성과 속도에 많은 단점을 가지고 있었다. 이러한 단점을 보완하고자 본 논문에서는 분산 객체 모델을 기반으로 peer-to-peer 구조를 가지는 새로운 원격교육시스템을 소개한다. DOVE(Distributed Object-oriented virtual computing environment)라는 분산 가상 환경 상에서 설계된 본 시스템은 peer-to-peer 구조를 가짐으로써 기존 시스템들의 확장성 문제를 해결했을 뿐만 아니라 DOVE의 가장 큰 장점 중에 하나인 객체 그룹(Object Group)의 개념을 도입하여 객체간에 멀티캐스트를 기반으로 한 상호작용을 가능케 함으로써 속도와 부하 문제도 해결하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.4
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• pp.73-80
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• 2016

Multiplayer Online Games(MOG) using the Internet are typically organized based on a CS(client-server) or P2P(peer-to-peer) architecture. We then propose a method that combines a P2P architecture with a CS architecture in order to utilize their advantages. Most MOGs use a primary-copy replication approach that provides strong consistency control over an object. For each object and character there exists an authoritative copy, called primary copy and all other copies are secondary copies or replicas. Any update to the object has to be first performed on the primary copy. In the proposed hybrid architecture, primary copies may reside on the server or be held by clients. In this architecture, load balancing between a server and clients can be achieved by reducing the number of objects maintained by the server. Games consist of various types of actions with different consistency requirements. A multi-level approach to game consistency is sensible as it provides the best trade-off between consistency and performance. The performance for the hybrid game architecture with the primary-copy model is evaluated through simulation experiments and analysis in this paper.

• Journal of KIISE:Information Networking
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• v.32 no.6
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• pp.705-715
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• 2005

A peer-to-peer web caching has been studied recently as it can reduce the traffic converged on the server side and can support the traditional web caching model. Although the peer-to-peer web caching has the merit of having additional cache space from the local caches of peers without additional infrastructure, several constraints such as dynamic participation and local caching strategy caused by the autonomy of peers in peer-to-peer networks nay limit the performance of the peer-to-peer web caching. To overcome these limitations, we propose an efficient directory-based peer-to-peer web caching system under dynamic participation of peers. In the proposed caching system, we present new peer selection and replica management schemes by introducing the concept of the object lifetime in P2P networks. We evaluate the effectiveness of the proposed system through trace-driven simulations with a web log dataset. Simulation results show that the proposed system has higher accuracy and fewer redirection failures than the conventional directory-based P2P web caching system in feasible peer-to-peer networks.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.4
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• pp.91-99
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• 2014

The main game architectures for multiplayer online games are the traditional client-server architectures, multi-server architectures and P2P(peer-to-peer) architectures. P2P architectures, due to their distributed and collaborative nature, have low infrastructure costs and can achieve high scalability as well as fast response time by creating direct connections between players. However, P2P architectures face many challenges. Distributing a game among peers makes maintaining control over the game more complex. These architectures also tend to be vulnerable to churn and cheating. Providing consistency control in P2P systems is also more difficult since conflicting updates might be executed at different sites resulting in inconsistency. In order to avoid or correct inconsistencies, most multiplayer games use a primary-copy replication approach where any update to the object has to be first performed on the primary copy. This paper presents the primary-copy model with the update dissemination mechanism that provides consistency control over an object in P2P architectures for multiplayer online games. The performance for this model is evaluated through simulation experiments and analysis.

• Journal of Korean Elementary Science Education
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• v.31 no.3
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• pp.311-320
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• 2012

The purpose of this study was to examine the effect of peer mentoring activity in elementary school. For this study, an experimental group was conducted for peer mentoring activity in science class. The mentoring team was organized by mento-mentee team according to the scores of science process skill and achievement. The objects of this study were the sixth grade of both an experimental group (28 students) and a control group (27 students) located in Incheon. The results of this study were as follows. First, the experimental group was shown more significant effect for improvement of science process skills than the control group (p<.05). As the result of analysis by groups, both of mento and mentee showed significant effect for improvement of science process skills. Second, the peer mentoring activity showed more significant effect for improvement of achievement (p<.05). As the result of analysis by groups, mentee showed significant effect for improvement achievement. But mento group didn't show significant effect. Third, the peer mentoring activity showed the effect for positive changes of scientific attitude. If matching the mentoring object effectively and conducting the classes applying peer mentoring activity based on the results of this study, it's expected to draw student' improvement of science academic, achievement and positive changes of scientific attitude.

• Journal of Korean Public Health Nursing
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• v.22 no.1
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• pp.84-96
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• 2008

Purpose: To consider how college students' adjustment to college life is related to peer attachment and self-esteem. Method: The subjects were 183 female college students attending one university. The study data were collected with the inventory of peer attachment-revised version, the self-esteem inventory, and the inventory for adjustment to college life. The data were analyzed by t-test, ANOVA, Pearson correlation coefficient and stepwise multiple regression. Results: There were significant differences in self-esteem according to residence type. There were significant differences in the adjustment to college life according to monthly income. There was a significantly positive correlation between peer attachment and adjustment to college life. There were significantly positive correlations between self-esteem and adjustment to college life and all of the subscales of adjustment to college life. Stepwise multiple regression analysis showed that 28.6% of the adjustment to college life was significantly explained by self-esteem and monthly income. Conclusion: Based on these findings, peer attachment is a very important factor influencing self-esteem which is itself a very important factor influencing adjustment to college life in female college students. Therefore, an alternative program designed to increase the self-esteem and peer attachment of female college students should be a planned program based on the study results.