• Journal of the Korean Society for information Management
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• v.23 no.1 s.59
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• pp.99-119
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• 2006

The most widely used information searching method in the current internet environment is the keyword-based one, which has certain limitations in terms of precision and recall. Most major internet portals provide directory-based searching as a means to complement these limitations. However, that they adopt different classification schemes brings significant inconvenience to the users, and it consequently suggests a need to develop mapping gateway to provide cross-portal, or cross-directory information searching. In this context, this study attempts to develop a prototype system of intermediary gateway for integrated search, using the directory services of three major portals, Naver, Yahoo and Empas, and test its performance.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.11b
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• pp.721-724
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• 2003

대부분의 이미지 검색은 질의 키워드를 이용하여 이루어지기 때문에 웹으로부터 수집한 이미지에는 미리 주제와 연관된 적절한 색인어를 부여하는 것이 필요하다. 웹 문서의 키워드를 이용하는 방법은 이미지와 연관성이 높은 것으로 간주되는 주변 키워드에 대해 각각의 연관도를 계산하여 색인어를 선정하는 방법이다. 본 논문에서는 이미지 주변의 키워드를 이용하여 이미지를 인덱싱한 후 유저 피드백을 통해 정확도를 높이는 웹 이미지 검색 모델을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10c
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• pp.317-320
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• 2006

본 연구에서는 한국교육학술정보원의 교육 콘텐츠 관리 시스템인 에듀넷의 키워드 기반 콘텐츠 검색기능을 고도화하기 온톨로지를 활용한 검색 프레임워크를 설계, 구현하였다. 에듀넷의 키워드 기반 검색 시스템에서 사용하는 KEM(Korea Education Metadata)를 owl을 이용하여 온톨로지로 바인딩하였으며, 의미 기반 교육 콘텐츠 검색이 가능하도록 중학교 수학의 일부 영역을 도메인 온톨로지로 구축하였다. 구축한 온톨로지에 실제 에듀넷에서 사용하는 콘텐츠 정보를 이용하여 인스턴스를 생성하였다. 사용자의 쿼리를 입력할 수 있는 인터페이스와 쿼리를 처리하고 추론할 수 있는 추론엔진을 사용하여 본 연구의 검색 시스템을 구축하였다. 실험을 통하여 본 연구에서 구축한 시스템이 키워드 매칭을 통한 검색 보다 사용자에게 의미 있고 유용한 결과를 도출함을 보였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.618-620
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• 2013

네트워크 및 컴퓨팅 기술의 발달로 데이터를 위탁 저장하고 이를 언제어디서든 다양한 단말로 처리 할 수 있는 클라우드컴퓨팅서비스가 활성화되고 있다. 특히 클라우드컴퓨팅 서비스 중 DaaS가 널리 사용되고 있다. 하지만, 위탁 저장된 데이터베이스에 신체 정보라던가 개인의 민감한 정보가 암호화 없이 저장된다면 서버에 저장된 데이터를 데이터 소유주의 동의 없이 공격자 및 비윤리적인 서버관리자가 열람할 수 있다는 보안 문제점이 있어 위탁 저장된 데이터베이스의 암호화가 필요하다. 하지만 기존에 사용되고 있는 암호화 알고리즘으로 암호화된 데이터를 안전하게 검색하기 위해선 암호화 데이터를 전부 데이터 소유자의 단말기에 내려 받고 전부 복호화해서 검색해야 하기에 데이터를 위탁 저장하는 의미가 퇴색된다. 이와 같은 문제를 해결하기위해 검색 가능한 암호시스템(Searchable Encryption System)이 등장하게 되었다. 하지만 기존의 검색가능 암호 시스템은 같은 키워드를 검색하기위해 생성된 트랩도어가 동일한 형태를 가지게 된다. 수많은 검색 쿼리들이 위탁저장소에 전송되며, 저장소의 관리자는 쿼리를 통해 키워드를 유추하고, 쿼리를 통해 사용자가 어떤 데이터를 저장하고 검색하는지 학습이 가능하기 때문이다. 따라서 본 논문은 동일한 사용자가 같은 키워드를 검색하더라도 매번 다른 트랩도어가 생성되도록 하여 비윤리적인 서버관리자가 검색 쿼리를 통해 검색 내용 및 데이터를 유추할 수 없도록 하는 일회용 트랩도어를 이용한 검색가능 암호 시스템을 제안한다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.19-28
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• 2015

Korea Digital Copyright Exchange of Korea Copyright Commission runs and manages copyrighted works and copyright license agreement, as well as assigns Integrated Copyright Number(ICN) to copyrighted works, also offers copyrighted works searching service. Keyword-based searching method based on ICN metadata provides results depending on the inclusion of metadata keyword. However, keyword-based searching method has limitations that cannot provide exact results that users need. Therefore, the essential method of offering exact result is needed. In this paper, we propose the semantic-based searching method about copyrighted works to increase the accuracy of searching results by extending ICN matadata to ontology, and implement the ontology of copyrighted works by defining relation and semantics about metadata elements. In order to compare semantic-based searching based on the ontology of copyrighted works with keyword-based searching method, the search results of each method according to 5 scenarios are presented and the accuracy of each method is compared.

• Journal of Information Technology and Architecture
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• v.9 no.3
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• pp.323-331
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• 2012

With the advancement of the area of knowledge and information, Intellectual Property, especially, patents have captured attention more and more emergent. The increasing need for efficient way of patent information search has been essential, but the prevailing patent search engines have included too many noises for the results due to the Boolean models. This has occasioned too much time for the professional experts to investigate the results manually. In this paper, we reveal the differences between the conventional document search and patent search and analyze the limitations of existing patent search. Furthermore, we propose a specialized in patent search, so that the relationship between the keywords within each document and their significance within each patent document search keyword can be identified. Which in turn, the keywords and the relationships have been appointed a ranking for this patent in the upper ranks and the noise in the data sub-ranked. Therefore this approach is proposed to significantly reduce noise ratio of the data from the search results. Finally, in, we demonstrate the superiority of the proposed methodology by comparing the Kipris dataset.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.285-292
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• 2013

The method of recent information retrieval passes into an semantic search to provide more accurate results than keyword-based search. But in common user case, they are still accustomed to using existing keyword-based search. Hence they are hard to create a typed structured query language. In this paper, we propose to ontology knowledge-base scheme for query interpretation of these user. The proposed scheme was designed based on the OWL-DL for description logic reasoning, it can provide a richer representation of the relationship between the object by using SWRL(Semantic Web Rule Language). Finally, we are describe the experimental results of the similarity measurement for verification of a user query semantic interpretation.

• The Transactions of the Korea Information Processing Society
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• v.4 no.6
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• pp.1418-1432
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• 1997

Most general content_based image retrieval techniques use color and texture as retrieval indices. In color techniques, color histogram and color pair based color retrieval techniques suffer from a lack of spatial information and text. And This paper describes the design and implementation of content_based image retrieval system using color space and keywords. The preprocessor for image retrieval has used the coordinate system of the existing HSI(Hue, Saturation, Intensity) and preformed to split One image into chromatic region and achromatic region respectively, It is necessary to normalize the size of image for 200*N or N*200 and to convert true colors into 256 color. Two color histograms for background and object are used in order to decide on color selection in the color space. Spatial information is obtained using a maximum entropy discretization. It is possible to choose the class, color, shape, location and size of image by using keyword. An input color is limited by 15 kinds keyword of chromatic and achromatic colors of the Korea Industrial Standards. Image retrieval method is used as the key of retrieval properties in the similarity. The weight values of color space ${\alpha}(%)and\;keyword\;{\beta}(%)$ can be chosen by the user in inputting the query words, controlling the values according to the properties of image_contents. The result of retrieval in the test using extracted feature such as color space and keyword to the query image are lower that those of weight value. In the case of weight value, the average of te measuring parameters shows approximate Precision(0.858), Recall(0.936), RT(1), MT(0). The above results have proved higher retrieval effects than the content_based image retrieval by using color space of keywords.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.1
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• pp.5-14
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• 2014

Searchable encryption systems provide search on encrypted data while preserving the privacy of the data and the search keywords used in queries. Recently, interest on data outsourcing has increased due to proliferation of cloud computing services. Many researches are on going to minimize the trust put on external servers and searchable encryption is one of them. However, most of previous searchable encryption schemes provide only a single keyword boolean search. Although, there have been proposals to provide conjunctive keyword search, most of these works use a fixed field which limit their application. In this paper, we propose a field-free conjunctive keyword searchable encryption that also provides rank information of search results. Our system uses prime tables and greatest common divisor operation, making our system very efficient. Moreover, our system is practical and can be implemented very easily since it does not require sophisticated cryptographic module.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.4
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• pp.3-10
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• 2011

To provide efficient keyword search on encrypted data, a public key encryption with keyword search (PEKS) was proposed by Boneh et al. A sender encrypts an e-mail and keywords with receiver's public key, respectively and uploads them on a server. Then a receiver generates a trapdoor of w with his secret key to search an e-mail related with some keyword w. However, Byun et al. showed that PEKS and some related schemes are not secure against keyword guessing attacks. In this paper, we propose a public key encryption with keyword search for restricted testability (PEKS-RT) scheme and show that our scheme is secure against keyword guessing attacks.