• Journal of Korea Multimedia Society
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• v.8 no.5
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• pp.606-617
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• 2005

There have been many research efforts which find efficiently all occurrences of the structural relationships between the nodes in the XML document tree for processing a XML query. Most of them use the region numbering which is based on positions of the nodes. Hut The position-based node numbering schemes require update of many node numbers in the XML document li the XML nodes are inserted frequently in the same position. In this paper, we propose ENN(extensible node numbering) scheme using the bucket number which is represented with the variable-length string for decreasing the number of the node numbers which is updated. We also present an performance analysis by comparing ENN method with TP(extended preorder) method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.6_2
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• pp.665-672
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• 2012

Amid rapidly increasing imagery inputs and their volume in a remote sensing imagery database, Content-Based Image Retrieval (CBIR) is an effective tool to search for an image feature or image content of interest a user wants to retrieve. It seeks to capture salient features from a 'query' image, and then to locate other instances of image region having similar features elsewhere in the image database. For a CBIR approach that uses texture as a primary feature primitive, designing a texture descriptor to better represent image contents is a key to improve CBIR results. For this purpose, an extended feature vector combining the Gabor filter and co-occurrence histogram method is suggested and evaluated for quantitywise and qualitywise retrieval performance criterion. For the better CBIR performance, assessing similarity between high dimensional feature vectors is also a challenging issue. Therefore a number of distance metrics (i.e. L1 and L2 norm) is tried to measure closeness between two feature vectors, and its impact on retrieval result is analyzed. In this paper, experimental results are presented with several CBIR samples. The current results show that 1) the overall retrieval quantity and quality is improved by combining two types of feature vectors, 2) some feature is better retrieved by a specific feature vector, and 3) retrieval result quality (i.e. ranking of retrieved image tiles) is sensitive to an adopted similarity metric when the extended feature vector is employed.

• Journal of Korea Society of Industrial Information Systems
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• v.9 no.1
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• pp.36-42
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• 2004

In this paper, we compare the vector model performance with the probabilistic model of information system. We use LSI(Latent Semantic Indexing) model for vector model, while Condor information search system that is ready to sell on business is used as a probabilistic model. Each model produces the search results from the original queries and the queries extended by a dictionary definition. We compare those results between two models and find out the vector model is much better than the probabilistic model for the most queries.

• Journal of the military operations research society of Korea
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• v.23 no.2
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• pp.85-102
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• 1997

There have been several research efforts to support interoperability among multiple databases. In integrating multiple databases, we must resolve schema conflicts due to the heterogeneity in databases. To resolve these conflicts, not only meta-data for database schemas but also general knowledge expressing the real world meanings associated with the database schemas are required. This paper presents a uniform representation method for relational schema and general knowledge base that is composed, among other things, of concept hierarchy and thematic roles in relationship, using the knowledge representation language Lk. This representation method has a flexible descriptive power which facilitates concepts to be expressed at different levels of granularity and can describe knowledge expressed in Lk are used for input of the next step, such as conflict resolution and query processing of multiple database.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.76-78
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• 2004

최근 원격 탐사 시스템 등이 발전함에 따라 축적된 공간 데이터의 양이 증가했고 이를 공간 데이터 웨어하우스 분야에서 의사 결정에 활용하는 방안이 중요한 이슈가 되고 있다. 기존의 활용 방법은 주어진 영역을 기준으로 공간 범위-집계를 검색하는 형태였지만, 최근 특정 성향 분석을 위해 분포 질의를 요청하고 그 결과 지역에 대한 공간 분석을 통한 의사결정의 필요성이 대두되었다. 하지만 기존의 처리 방법으로 비공간 질의를 처리하기 위해서는 모든 데이터를 검색해야 하므로 분포 질의를 처리하기 위한 비용이 증가하게 된다. 본 논문에서는 분포 지역 질의 처리를 위한 확장된 큐브 트리 기법을 제안한다. 제안하는 기법은 분석하고자 하는 사실 테이블의 비공간 속성을 큐브 트리의 키로 사용하고, 이 속성과 관련된 공간 데이터의 포인터 집합을 관리한다. 본 논문의 제안 기법을 공간 데이터 웨어하우스에 적용함으로써 비공간 속성 질의를 통해 공간 객체를 결과로 요청하는 형태의 질의를 지원할 수 있게 되며 사실 컬럼을 계층화시킴으로서 사용자에게 좀 더 다각적인 분석을 지원할 수 있다.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.2
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• pp.1-11
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• 2005

The network structures of a hyperlinked environment can be a rich source of information about the contents of the environment and it provides effective means for understanding it. Recently, there have been a number of algorithms proposed analyzing hypertext link structure so as to determine the best authorities for a given topic or query. In this paper, we review the algorithm of mutual reinforcement relationship for finding hubs and authorities from World Wide Web, and suggest SHA, a new approach for link-structure analysis, which uses the relationships among a set of relative authoritative pages, a set of hub pages, and a set of super hub pages.

• Journal of Computing Science and Engineering
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• v.8 no.2
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• pp.65-77
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• 2014

To address the problem of multi-target retrieval (MTR) of remote sensing images, this study proposes a new object-level feature representation model. The model provides an enhanced application image representation that improves the efficiency of MTR. Generating the model in our scheme includes processes, such as object-oriented image segmentation, feature parameter calculation, and symbolic image database construction. The proposed model uses the spatial representation method of the extended nine-direction lower-triangular (9DLT) matrix to combine spatial relationships among objects, and organizes the image features according to MPEG-7 standards. A similarity metric method is proposed that improves the precision of similarity retrieval. Our method provides a trade-off strategy that supports flexible matching on the target features, or the spatial relationship between the query target and the image database. We implement this retrieval framework on a dataset of remote sensing images. Experimental results show that the proposed model achieves competitive and high-retrieval precision.

• Annual Conference of KIPS
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• 2005.11a
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• pp.105-108
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• 2005

공간 연관 규칙은 공간적 특성을 바탕으로 발견되는 연관 정도를 나타낸다. 그러나 일반적인 공간 데이터베이스에서는 공간 연관 규칙을 발견하기 어렵다. 따라서 본 논문에서는 공간 데이터베이스에서 사용되는 질의를 확장하여 공간 연관 규칙을 찾는 방법을 제안한다. 본 논문에서 제안하는 시스템은 위상 정보에 따른 데이터를 구성한 후 비공간 객체 속성간의 연관규칙을 발견한다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.142-144
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• 2005

공간 연관 규칙은 공간적 특성을 포함하며 빈발하게 발견되는 연관 객체들의 집합이다. 그러나 객체의 위상과 그 객체의 비공간 속성을 갖는 일반적인 공간 데이터에이스에서는 공간 연관 규칙을 발견할 수 없다. 따라서 본 논문에서는 일반적인 공간 데에터베이스 시스템의 질의 언어를 확장하고 이를 이용하여 공간 연판 규칙을 발견할 수 있는 시스템을 구현하였다.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.69-76
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• 1999

Recently, it has been studied the methods to materialize and precompute the query results for complexed spatial aggregation queries with high response time and the popular use in spatial data warehouse. In this paper, we propose extended selective materialization algorithm and present the way to materialize selectively which is considered access frequency and computation time of spatial operation according to spatial measures of spatial views for improvement of existing selective materialization algorithms.