• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.643-648
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• 2005

In order to supply services necessary for users intelligently in the ubiquitous computing, effective filtering of context information is necessary. But studies of context information filtering have not been made much yet. In order for filtering of context information, we can use collaborative filtering being used much at electric commerce, etc. In order to use such collaborative filtering method in the filtering of ubiquitous computing environment, we must solve such problems as first rater problem, sparsity problem, stored data problem and etc. In this study, in order to solve such problems, the researcher proposes the collaborative filtering method using types of context information. And as the result of applying this filtering method to MAUCA, the P2P mobile agent system, the researcher could confirm the average result of 7.7% in the aspect of service supporting function.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.766-773
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• 2007

Conventional wireless sensor network(WSN) has limited power and bandwidth. In order to develop multimedia sensor technology, high data rate communication systems are required. Cooperative communication system can help to decrease power consumption through spatial diversity. In cooperative transmission, one partner node assists one sensor node to transmit their data to destination. Instead of using M partners for M sensor nodes, we propose 1 partner for M sensor nodes. Proposed protocol offers similar diversity order as conventional one with much less bandwidth and hardware. It is able to almost reduce scattered nodes interference using orthogonal sub-carriers. In addition, we examined a power allocation between sensor nodes and relay that optimize the system performance.

• The KIPS Transactions:PartD
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• v.11D no.5
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• pp.1177-1188
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• 2004

Multi-agent systems have been developed for supporting intelligent collaboration of distributed and independent software entities and are be-ing widely used for various applications. For the collaboration among agents, conversation policies (or interaction protocols) mutually agreed by agents are used. In today's dynamic electronic market environment, there can be frequent changes in conversation policies induced by the changes in transaction methods in the market, and thus, the importance of ad hoc conversation policies is increasing. In existing agent platforms, they allow the use of only several standard or fixed conversation policies, which requires inevitable re implementation for ad hoc conversation policies and leads to inefficiency and intricacy. This paper designs an agent platform that supports ad hoc conversation policies and presents the prototype implementation. The suggested system includes an exchangeable and interpretable conversation policy model, a meta conversation procedure for exchanging new conversation policies, and a mechanism for performing actual transactions with exchanged conversation policies in run time in an adaptive way.

• Journal of the Korean Society for information Management
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• v.26 no.3
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• pp.239-259
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• 2009

The study aims at investigating students' behaviors and perceptions regarding the collaborative learning based group project using the wiki environment. The study utilized Google Sites as a case, and analyzed file unloads, the use of web pages, navigation bars, and comments as well as surveys. The study discusses main characteristics of students' activities in the collaborative learning group project, which are drawn from the analysis of students' behaviors and perceptions. The study also provides implications for improvement of wiki environment to support collaborative learning in education.

• Journal of Broadcast Engineering
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• v.20 no.3
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• pp.464-467
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• 2015

The CBS functionality is defined for emergency alert service in cellular systems. Previously, a cooperative communication technique was proposed for more reliable CBS functionality. However, the relays for cooperative communications may fail in receiving emergency message, which may cause a critical latency. Therefore, we propose a novel cooperative communication technology in this letter, which incudes additional T-DMB functionality in relays. Analytical and empirical evaluations confirm that the proposed method is very suitable for rapid emergency alert broadcast.

• Korean Security Journal
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• no.61
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• pp.203-234
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• 2019

The damages from security accidents continue to increase as technology leaks from suppliers cause risks to the management of large companies, which are their customers, and their image and reliability to fall. However, the current industrial structure is practically impossible for large companies to form their own businesses and strategic alliances with business partners are essential, but it is changing into an industrial structure where the exchange of information is increased and the dependence of the information system is maximized, as well as legal demands and demands from stakeholders are increasing due to the complexity of the work process and the strengthening of security-related laws. The status of technology protection of small and medium-sized enterprises shows that they are not equipped with a security system due to relatively poor environment and financial difficulties compared to large enterprises, whereas the industrial structure between large and small business partners is indispensable for sharing the IT system, and the security system of large business, which is a customer company, should be improved by considering the fact that it is impossible to maintain security system between large businesses. Thus, the government intends to examine the system for shared growth of small businesses and the model for evaluating the capabilities of various agencies for information protection, and propose measures to introduce the certification system for small business partners.

• Journal of The Korean Association For Science Education
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• v.38 no.5
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• pp.667-680
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• 2018

The purpose of this study is to investigate 1) the types of knowledge students ask for in their reading comprehension of science textbooks using an online annotation system, 2) the accuracy of the knowledge provided by the students to their peers, 3) the frequency of knowledge sharing behaviors, 4) the evaluation of the effect of collaborative reading, and 5) the trust among peers as knowledge sharers. Questions made by 241 students in the second grade of middle school using an online annotation system in two chapters of the science textbook were analyzed using Bloom's revised taxonomy and their answers were grouped according to five accuracy categories. Also, questionnaires for the evaluation of the effectiveness of collaborative reading comprehension and of trust among the students were used. The students asked their peers 'understanding questions' which comprised almost 80% of the total questions they made and were similar with individual metacognitive strategies for reading comprehension. Of the total threads, 71% has scientifically correct threads shared by the students. The frequency of the knowledge sharing behaviors was high but this was affected by the rewards (point system). Students evaluated that collaborative reading comprehension conducted through an online annotation system were helpful in their learning. In addition, the ratio of students trusting their peers who did the knowledge sharing is over 80%. This study shows that when students use an online annotation system, they can fill one another's cognitive gaps in the reading process by sharing knowledge. Also, collaborative reading using an online annotation system has proved that cognitive individualization is possible through sharing knowledge interactively and dynamically, unlike reading hard copies of textbooks which are a one way information transfer.

• ICROS
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• v.3 no.1
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• pp.33-40
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• 1997

본 연구는 홀로닉 생산시스템의 개요와 연구 방향에 관한 것으로써 홀로닉 생산시스템의 출현 배경, 개념, 기존 연구결과 및 주요 연구 분야에 대하여 서술하였다. 생산시스템은 하드웨어의 발전과 더불어 이의 운영 기법이 시대에 필요에 맞게 발전해 왔는데 홀로닉 생산시스템은 오늘날의 소비 패턴과 시스템 내외의 환경 변화에 부응하여 새롭게 제시된 시스템이다. 시스템의 구성요소들은 자신의 목표를 수행하면서 동시에 시스템 공동의 목표 수행을 위해 서로 협력 및 협상한다. 아직까지 뚜렷한 시스템이 구축되어 가동되고 있는 예는 없고, 연구 중에 있지만 홀로닉 생산시스템은 차세대 생산시스템의 새로운 방향을 제시할 수 있을 것으로 사료된다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.111-116
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• 2015

This article considers a model of cooperative spectrum sharing between primary and secondary systems in which transmission occurs in two phases. In this scheme, we introduce that a single secondary transmitter, ST, employs a quadrature-phase-based signal to present the secondary message, while the primary message is presented by an in-phase-based signal. This allows simultaneous spectrum sharing without mutual interference. Therefore, an interference constraint is not necessary to protect primary operating performance from being degraded by the secondary user operations. Theoretical analysis and Simulations are then provided to confirm the superiority of the proposed scheme over the the current conventional methods.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.73-75
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• 2004

본 논문에서는 멀티플랫폼 환경에서 헙력학습을 지원하는 e-Learning 시스템을 소개한다. 현재 IT 기술이 발전하면서 학습을 할 수 있는 단말의 종류는 과거에 비해 다양하다. 이러한 다양한 단말로 학습콘텐츠를 상호운용 시키기 위해서는 콘텐츠의 적응화가 필요하다. 본 연구에서는 적응화 방법을 소개하며 적응화를 위한 시스템의 architecture를 소개한다. 본 논문에서는 두 가지 적응화 방법을 고려한다. 학습콘텐츠 레이아웃 적응화와 학습자원의 적응화가 고려된다. 또한 학습효율을 향상하기 위해 협력학습을 지원하는 기술을 개발한다. 현재 ISO/IEC JTC1 SC36 WG2에서 헙력학습에 관한 기술표준을 추진 중이므로 본 논문에서는 SC36의 초안에 따라 기술을 개발하여 추후 국제표준을 선도할 것이다.