• Journal of Internet Computing and Services
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• v.11 no.4
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• pp.11-22
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• 2010

In case that group communication protocols assume every process is interested in all events occurring in a large scale group, the events multicasting to a subset of a large process group, such as a sensor network, potentially varying for every event based on their interests might lead to very high communication overhead on each individual process. Moreover, despite the importance of both guaranteeing message delivery order and supporting overlapped group using gossip based group communication for multicasting in sensor or P2P networks, there exist little research works on development of gossip-based protocols to satisfy all these requirements. In this paper, we present a new gossip-based causal message order guaranteeing multicast protocol based on local views and delegates representing subgroups and fully utilizing multi-group features to improve scalability. In the proposed protocol, the message delivery order in overlapped groups has been guaranteed consistently by all corresponding members of the groups including delegates. Therefore, these features of the proposed protocol might be significantly scalable rather than those of the protocols guaranteeing atomic order dependencies between multicast messages by hierarchical membership list of dedicated groups like traditional committee protocols and much stronger rather than fully decentralized protocols guaranteeing dependencies between multicast messages based on only local views. And the proposed protocol is a hybrid approach improving the inherent scalability of multicast nature by gossip-based technique in all communications.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.299-300
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• 2010

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.10B
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• pp.865-875
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• 2008

In this paper, we propose a reliable multicast scheme for the tactical wireless ad hoc network where the members share the situation and operation data. Our scheme consists of two phases to guarantee the reliability. During the dissemination phase, we utilizes an epidemic approach similar to gossip-based ad hoc routing. Then the group members interchange the message reception state information periodically so that they are able to recover missing packets from the other members. We evaluate the performance of our scheme through extensive simulations using the network simulator in comparison with other existing reliable multicast schemes in mobile ad hoc network. Our scheme shows higher packet delivery ratio regardless of the mobility and imposes much lower control overhead to the non-group members compared with the existing schemes.

• Journal of Information Processing Systems
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• v.9 no.3
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• pp.477-488
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• 2013

Wireless Sensor Networks (WSNs) are comprised of sensor nodes that forward data in the shape of packets inside a network. Proficient packet forwarding is a prerequisite in sensor networks since many tasks in the network, together with redundancy evaluation and localization, depend upon the methods of packet forwarding. With the motivation to develop a fault tolerant packet forwarding scheme a Self-Localized Packet Forwarding Algorithm (SLPFA) to control redundancy in WSNs is proposed in this paper. The proposed algorithm infuses the aspects of the gossip protocol for forwarding packets and the end to end performance of the proposed algorithm is evaluated for different values of node densities in the same deployment area by means of simulations.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.164-167
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• 2012

합의는 분산 시스템 환경에서 해결해야 할 근본적인 문제 중 하나이다. 특히 노드 또는 프로세스의 임의적인 실패 즉, 비잔틴 실패가 발생하였을 때 합의 문제는 더 복잡해진다. 본 연구에서는 동적인 노드의 가입과 탈퇴가 자유로운 클라우드 환경에서 비잔틴 합의 문제를 해결하기 위한 가쉽 알고리즘을 제안한다. 제안하는 알고리즘에서 확장성과 결함 포용의 특성을 내재한 가쉽 알고리즘을 적용함으로써 클라우드 환경에서의 비잔틴 합의 문제를 확장적이고 결함 포용적으로 해결할 수 있다. 알고리즘의 성능을 분석하기 위해 성능 평가를 수행하였다.

• The Korean Journal of Elementary Counseling
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• v.7 no.1
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• pp.135-163
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• 2008

This study intends to confirm if it is effective in improving the problem behaviors by applying "Logical Consequence" suggested by Adler to the class management. The researcher who is in charge of the 4th grade class of elementary school in G city applied Adlerian logical consequence to her children, observed and examined the effectiveness of reducing the problem behaviors by the qualitative study method of in-depth interview from March to October. The problem behaviors treated in this study includes irrelevant remarks and gossip in school time, no preparation for taking lessons in time, no preparation of a textbook and a supply, no involvement in doing homework, scribbling and poor handwriting on a textbook, teasing a friend (abusive language, joking, violence), indoor running, no involvement in doing a task, being late and no arrangement of indoor shoes. In conclusion, this study indicated that the use of Logical Consequence was relatively effective in improving the problem behaviors and more effective in individual behaviors rather than group's behaviors. While the problem behaviors conducted in a class in the daily routine were effective at the point of the occurred problems, the problem behaviors occurred at the point of time related to a home or the finish of daily routine were ineffective.

• Education of Primary School Mathematics
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• v.19 no.4
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• pp.361-380
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• 2016

This study aims to reflect on mathematical imaginations in learning mathematics and elementary students' mathematical imaginations. This was approaching a study of imagination not as psychological problems but as objects and methods of mathematics learning. First, children's mathematical narratives were analysed in terms of Egan(2008)'s basic cognitive tools using imagination, that is, metaphor, binary opposites, rhyme rhythm pattern, jokes humor, mental imagery, gossip, play, mystery. Second, how children's imaginations change under different grades was addressed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.1
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• pp.87-96
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• 2013

Influence propagation is an important research issue in social networks. Influence propagation means that the status or the disposition of nodes get changed by new idea, information and gossip propagated by other nodes. Influenced nodes also make other nodes influenced across the network. The influence propagation problem based on 'word of mouth' referral is to find most influential nodes set in networks to maximize influence. In this paper, we study the influence measuring and finding most influential nodes set in Delay-Tolerant Networks. It is difficult to measure exact influential power in Delay-Tolerant networks where network topology is not stable due to the nodal mobility. In this paper, we propose a distributed scheme that each node constructs $k$-clique community structure and estimates local influential power in Delay-Tolerant Networks. Simulation results show that the influential nodes information estimated by proposed scheme is in agreement with a global view of influential nodes information.

• Journal of Computing Science and Engineering
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• v.2 no.3
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• pp.249-273
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• 2008

Epidemic protocols have two fundamental assumptions. One is the availability of a mechanism that provides each node with a set of log(N) (fanout) nodes to gossip with at each cycle. The other is that the network size N is known to all member nodes. While it may be trivial to support these assumptions in small systems, it is a challenge to realize them in large open dynamic systems, such as peer-to-peer (P2P) systems. Technically, since the most fundamental parameter of epidemic protocols is log(N), without knowing the system size, the protocols will be limited. Further, since the network churn, frequently observed in P2P systems, causes rapid membership changes, providing a different set of log(N) at each cycle is a difficult problem. In order to support the assumptions, the fanout nodes should be selected randomly and uniformly from the entire membership. This paper investigates one possible solution which addresses both problems; providing at each cycle a different set of log(N) nodes selected randomly and uniformly from the entire network under churn, and estimating the dynamic network size in the number of nodes. This solution improves the previously developed distributed algorithm called Shuffle to deal with churn, and utilizes the Shuffle infrastructure to estimate the dynamic network size. The effectiveness of the proposed solution is evaluated by simulation. According to the simulation results, the proposed algorithms successfully handle network churn in providing random log(N0 fanout nodes, and practically and accurately estimate the network size. Overall, this work provides insights in designing epidemic protocols for large scale open dynamic systems, where the protocols behave autonomically.

• The Research Journal of the Costume Culture
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• v.16 no.6
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• pp.1019-1034
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• 2008

The purpose of this study is to grasp creation background and social position of courtesan which is treated in social and cultural context and its effect on fashion and research representative courtesans from ancient hetaera to the 19th century and their costume characteristics. Its another purpose is to analyze the costume of Violetta, who is a heroine of opera and its costume characteristic as a courtesan. Most Courtesan clothing were made from bright color, silk and lace which were light, or transparent materials. Using silk and cashmere which were the symbols of class, she took the cutting edge fashion and struggled to break the social barriers. The clothing which the Courtesan wore always became a gossip among people and popular to the designers who could show their creativities because the Courtesan boldly wore the cloth like movie actresses or stars. The Courtesan who led the fashion not only showed the fashion as a simple expression of the beauty but also as a socio-cultural phenomenon which reflected their social awareness with arts, and changed according to the situations of the time and people. Violetta's party dress which was shown in the first and third acts of showed the shoulders and chest because of the deep and wide cut decollete, the waist was tightened with a corset as much as possible, and the opulent hips were inflated by the crinoline so when they walked it was swaying. Also it was decorated with splendid materials such as silk and lace, and sparkling jewels, fans, and neckless and even in case of the general clothing in the second act, it was decorated with braids and lace, frills and ribbons. In the third act, the weakness of the sick woman who was closing her life as the splendid Courtesan was emphasized by using colors of white and light purple and thin transparent materials.