• 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.

• ETRI Journal
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• v.3 no.3
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• pp.44-50
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• 1981

• Proceedings of the Korea Information Processing Society Conference
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• 2015.04a
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• pp.366-369
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• 2015

온라인 전자 상거래 시장은 인터넷의 발전과 그 편의성으로 인하여 지속적으로 시장 규모가 커지고 있다. 비대면 결제방식인 온라인 전자결제 방식은 오프라인 결제 방식에 비해 높은 수준의 안전성이 요구된다. 결제정보가 노출된다면 공격자는 타인의 결제정보를 이용하여 불법적인 결제가 가능할 것이다. 현재 사용되고 있는 온라인 결제 시스템들은 결제정보를 안전하게 전송하기 위한 프로토콜을 구성하고 있지만 실제 해킹을 통한 결제정보 유출로 인해 최근 몇 년간 다수의 금융사고들이 일어나고 있다. 본 논문은 Two-Session 결제 방식을 이용해 국내 온라인 결제 시스템을 보완하여 향상된 보안성으로 결제정보를 전송하여 결제정보의 유출을 예방하고 기존 시스템 대비 높은 사용자 편리성을 가지는 시스템을 제안한다.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.8
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• pp.601-605
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• 2009

Recently, photo sharing and publishing based Social Network Sites(SNSs) are increasingly attracting the attention of academic and industry researches. Millions of users have integrated these sites into their daily practices to communicate with online people. In this paper, we propose an efficient face annotation and retrieval system under SNS. Since the system needs to deal with a huge database which consists of an increasing users and images, both effectiveness and efficiency are required, In order to deal with this problem, we propose a face annotation classifier which adopts an online learning and social decomposition approach. The proposed method is shown to have comparable accuracy and better efficiency than that of the widely used Support Vector Machine. Consequently, the proposed framework can reduce the user's tedious efforts to annotate face images and provides a fast response to millions of users.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2002.11a
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• pp.3-6
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• 2002

권한 관리 기반 구조(PMI: Privilege Management Infrastructure)란 공개키 기반 구조(PKI: Public key Infrastructure) 와 연동되어 온라인 상에서 사용자의 신원정보와 권한 또는 속성 정보를 연결하여 자원에 대한 접근 관리를 효율적이고 안전하게 할 수 있도록 해주는 정보 보호 인프라이다. 이러한 권한 관리 기반 구조에서 사용되는 인증서를 속성 인증서(Attribute Certificate) 또는 PMI 인증서라고 부른다. 속성 인증서가 기반 구조 내에서 통용되어 사용되기 위해서는 표준화 기관에서 정의한 표준 규격을 따라야 하며 유효성을 해치지 않는 올바른 값들로 인증서 내용이 채워져 있어야 한다. 이와 같이 특정 단체나 어플리케이션에 의해 생성·사용되는 속성 인증서 등이 기반 구조내의 개체들 간에 서고 호환되어 사용될 수 있는지 검사하는 것을 적합성 평가라고 한다. 본 연구에서는 속성 인증서 및 인증서 요청 메시지의 적합성 평가를 위한 평가 시스템을 구성하고 평가 시 요구되는 평가 항목 및 평가 기준을 정의한다.

• Journal of Intelligence and Information Systems
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• v.10 no.2
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• pp.147-163
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• 2004

For the purchase of a cheaper product on the Internet, many customers have been trying to search online shopping mall sites and visit comparison-pricing shops that compare prices and other criteria of the product. Others have been participating into online auction markets or group-buying markets. However, a lot of online shopping malls, auction markets, and group-buying markets provide the same product with different prices. Since these marketplaces have different price settlement mechanism, it is very difficult for the customers to determine marketplace to purchase, considering different kinds of marketplaces at the same time. To overcome such limitations, decision rules and solution procedures for purchase decision making are necessary, which can cover multiple marketplaces simultaneously. For this purpose, purchase decision making in each market must be conducted to maximize customer's utility, and conflicts with other marketplaces must be resolved. Therefore, we have developed the rules and methods that can negotiate cooperatively the purchase decision making in several marketplaces, and designed an architecture of Intelligent Buyer Agent and a message structure to support the idea.

• Journal of KIISE:Information Networking
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• v.32 no.3
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• pp.310-317
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• 2005

In opposition to conventional networks, mobile ad hoc networks usually do not offer trust about nodes or online access through certificate authorities or centralized servers. But, nodes in those systems need process that can search path as well as trust each other to exchange data in safety For these reasons, traditional security measures that require online trusted authorities or certificate storages are not well-suited for securing ad hoc networks. In this paper, I propose a secure and effective method to search the optimized path using profitable flooding techniques on certificate chains in MANETS(Mobile Ad hoc NETworks). This system includes not only using routing protocols that are generally broadcasting packets but also finding nodes securely and verifing the process through tiust relationships between nodes that are searched.

• Journal of Korea Multimedia Society
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• v.12 no.10
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• pp.1486-1498
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• 2009

Modem efforts on digitizing electronic books focus on preserving authentic image representation of the original sources. Unlike the text-based format, it is difficult to recognize the information in the image, so the new format requires new tools to help users to access, process, and make sense of digital information. This paper presents an approach which assists users of these image sources by giving them a combination of annotation and social navigation support. Especially in the education domain, the proposed technique improves the usability of online education system. This approach is currently fully implemented and under evaluation in a classroom study.

• The KIPS Transactions:PartA
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• v.9A no.3
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• pp.387-398
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• 2002

As whole genome sequences of many organisms have been revealed by small-scale genome projects, the intensive research on individual genes and their functions has been performed. However on-memory algorithms are inefficient to analysis of whole genome sequences, since the size of individual whole genome is from several million base pairs to hundreds billion base pairs. In order to effectively manipulate the huge sequence data, it is necessary to use the indexed data structure for external memory. In this paper, we introduce a workbench system for analysis and visualization of whole genome sequence using string B-tree that is suitable for analysis of huge data. This system consists of two parts : analysis query part and visualization part. Query system supports various transactions such as sequence search, k-occurrence, and k-mer analysis. Visualization system helps biological scientist to easily understand whole structure and specificity by many kinds of visualization such as whole genome sequence, annotation, CGR (Chaos Game Representation), k-mer, and RWP (Random Walk Plot). One can find the relations among organisms, predict the genes in a genome, and research on the function of junk DNA using our workbench.