• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.563-573
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• 2006

Cyber-infrastructures for scientific and engineering applications require integrating heterogeneous legacy data in different formats and from various domains. Such data integration raises challenging issues: (1) Support for multiple independently-managed schemas, (2) Ease of schema evolution, and (3) Simple schema mappings. In order to address these issues, we propose a novel approach to semantic integration of scientific data which uses XML schemas and RDF-based schema mappings. In this approach, XML schema al-lows scientists to manage data models intuitively and to use commodity XML DBMS tools. A simple RDF-based ontological representation scheme is used for only structural relations among independently-managed XML schemas from different institutes or domains We present the design and implementation of a prototype system developed for the national cyber-environments for civil engi-neering research activities in Korea (similar to the NEES project in USA) which is called KOCEDgrid (http://www.koced.net).

• Journal of KIISE:Databases
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• v.41 no.4
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• pp.242-248
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• 2014

With the rapidly growing amount of information represented in RDF format, efficient querying of RDF graph has become a fundamental challenge. SPARQL is one of the most widely used query languages for retrieving information from RDF dataset. SPARQL is not only simple in its syntax but also powerful in representation of graph pattern queries. However, users need to make a lot of efforts to understand the ontology schema of a dataset in order to compose a relevant SPARQL query. In this paper, we propose a graph query formulation and processing scheme based on ontology schema information which can be obtained by summarizing RDF graph. In the context of the proposed querying scheme, a user can interactively formulate the graph queries on the graphic user interface without making efforts to understand the ontology schema and even without learning SPARQL syntax. The graph query formulated by a user is transformed into a set of class paths, which are stored in a relational database and used as the constraint for search space reduction when the relational database executes the graph search operation. By executing the LUBM query 2, 8, and 9 over LUBM (10,0), it is shown that the proposed querying scheme returns the complete result set.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.35-45
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• 2009

According to the widespread use of ontology documents, a management system which store ontology data and process queries is needed for retrieving semantic information efficiently. In this paper I propose a storage schema that stores and retrieves semantic web documents based on RDF/RDFS ontology language developed by W3C in a relational databases. Specially, the proposed storage schema is designed to retrieve efficiently hierarchy information and to increase efficiency of query processing. Also, I describe a mechanism to transform RQL semantic queries to SQL relational queries and build up database using MS-ACCESS and implement in this paper. According to the result of implementation, we can blow that not only data query based on triple model but also query for schema and hierarchy information are transformed simply to SQL.

• Journal of Information Management
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• v.34 no.3
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• pp.87-109
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• 2003

Continual attempts to accumulate and apply information eventually gave birth to the concept of the "Semantic Web". Thus, the "Semantic Web" can be defined as a product of mankind's desire to standardize information. At the same time, the term provides "a method that standardizes mankind's concept of linguistical expression", and can be noted as an effort to combine such methods into a standard web environment that may materialize to form a catalogue. This study introduced RDF schema, ontology languages for the semantic web, and ontology-based systems. The purpose of the study was to construct a system based on the semantic web environment's ontology by utilizing the ontology schema derived from the facettype Art and Architecture Thesaurus(AAT). The aforementioned ontology schema is based on the Web Ontology Language(OWL), which is being widely considered the standard ontology language for the W3C-centered semantic web environment.

• The Journal of Society for e-Business Studies
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• v.9 no.3
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• pp.79-94
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• 2004

W3C has developed the RDF standard for utilizing ontology in Web applications. This paper presents extracting, storing, and applying ontology on product data. The management and document information included in DWG files is focused as an example. By analyzing the relationship among the drawing data, the RDF schema is designed frist. Based on the schema ontology is extracted and stored in XML files. As an application of the stored ontology, we the schema ontology is extracted and stored in XML files. As an application of the stored ontology, we can reconfigure the sitemap of drawing data repositories. In this example, the users can select the view that he or she is interested in (e.g., designer, document, project). With such various views of an drawing data repository, the users can access the specific data more effectively.

• The Journal of the Korea Contents Association
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• v.5 no.6
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• pp.1-9
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• 2005

As the amount of data on the web increase, it is difficult to search what we want exactly. Therefore, much researches are attempted to search web resources efficiently. So, W3C established the standard that give meanings to resources on the web using RDF metadata. The RDF metadata had been mainly described a document data on the web. But it is difficult to create automatically the metadata for application programs than the document data. This paper proposes a method to use RDF metadata to search application programs. Firstly, we define RDF data model that stores the information of the application programs and RDF schema that references the RDF data model. And we design a prototype system to search application programs. This system meets expectation, getting the application to fullfill the needs of user, and has the efficiency of the searching function.

• Journal of Digital Contents Society
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• v.8 no.4
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• pp.499-507
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• 2007

With the increasing of users' request about internet web service, importance of Internet datawarehouse to support decision making of users is increasing now. Early Internet datawarehouse was studied in the form of using existent database and XML. However, because of limitation of information expression ability, it is gradually changed to system that use metadata schema like RDFS. Because of distributed environment of the Internet, integration and saving of each metadata schemas into one global schema is important. However, between each different schema, semantic and structural conflicts can be happen in such situation and they must be controlled. In this paper, we analyze occasions of conflict when integrate distributed metadata schemas and propose conflict resolution technique for efficient internet datawarehouse query processing.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.643-645
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• 2004

시맨틱 데이터는 인간이 의도한 정보를 효과적으로 기계에게 전달하는 정보 양식이다. 그러나 시맨틱 정보를 웹 브라우저를 통해 CGI 코드로 처리하는 방식은 정보 시스템내의 정보구조와 이의 처리 코드가 고착되는 문제점을 안고 있었다. 이를 해결하기 위해 본 논문에서는 시맨틱 정보를 담는 RDF 술어를 기술하는 XML 스키마를 제안한다. 해당 스키마로 기술된 RDF 술어는 HTML 폼으로 자동으로 생성되며, 해당 폼에서 받아들인 데이터를 기반으로 대응되는 RDF 문서를 생성하는데 사용된다. 제안된 스키마를 이용함으로써, 정보 시스템 내에서 RDF 구조의 동적인 변경이 용이하며, 표준화된 방식의 RDF 데이터 입력이 가능해지는 효과를 얻게 된다.

• Korean Journal of Computational Design and Engineering
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• v.10 no.2
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• pp.97-106
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• 2005

W3C has developed the RDF standard for utilizing ontology in Web applications. This paper presents extracting, storing, and applying ontology on product data. The design and tooling information included in STEP-NC files is focused as an example. By analyzing the relationship among the product data, the RDF schema is designed first. Based on the schema ontology if extracted and stored in XML files. As an application of the stored ontology, we can reconfigure the sitemap of product data repositories. In this example, the users can select the view that he or she is interested in (e.g. product, tool, person). With such various views of an product data repository, the users can access the specific data more effectively.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.64-68
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• 2007

본 논문은 영상의 메타데이터를 RDF를 이용하여 표현, 저장하고, SPARQL을 이용하여 검색하는 솔루션을 구현하여, RDF와 SPARQL을 통한 멀티미디어 파일의 메타데이터 관리 방안을 제시한다. 솔루션은 Jena2 프레임워크 기반으로 구현하였으며, Controller, EXIF Extractor, Metadata Schema, RDF Generator, Repository Manager, SPARQL Executor의 모듈로 구성된다.