• Annual Conference of KIPS
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• 2004.05a
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• pp.573-576
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• 2004

시맨틱 웹에 이용되는 웹 온톨로지 언어들로는 RDF/RDFS, DAML+OIL, OWL 등이 있으며, 현재 W3C에서는 OWL을 웹 온톨로지 표준 언어로 삼고 있다. 기존의 웹 온톨로지 문서들의 파서는 대부분 RDF를 기반으로 한 Triple 모델을 기반으로 하여 파싱한다. 그러나 OWL의 경우는 triple 형태로 변환시키면 OWL Full의 형태를 가지게 되고 OWL 온톨로지의 표현력과 데이터의 손실을 가져오게 된다. 따라서 OWL 문서의 파싱을 위하여 우리는 OWL Abstract Syntax를 이용하여 Tree 모델을 가지는 OWL 파서를 만들고자 한다. 본 논문에서는 시맨틱 웹에서 사용되는 웹 온톨로지들을 파싱하여 온톨로지 객체 모델을 생성해주는 기능을 가지는 온톨로지 파서를 설계, 구현하였다. 논문에서 설계한 온톨로지 파서는 RDF, DAML+OIL, OWL 웹 온톨로지 문서들을 파싱하여 온톨로지 객체 모델을 생성할 때, RDF 온톨로지의 경우는 Triple 모델 형태로 파싱을 하지만, OWL 온톨로지의 경우에는 OWL Abstract Syntax Tree 모델 형태로 파싱한 후, OOM으로 변환시켜준다. 이를 위해 웹 온톨로지 언어의 종류 구분과 OWL 온톨로지의 경우, OWL Full, OWL DL, OWL Lite의 서브 타입을 구별하는 기능도 추가하였다.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.7
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• pp.875-880
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• 2005

OWL(Web Ontology Language) is the Ontology Standard Language and the a lot of Ontologies are being constructed in OWL. But the research on the extension of OWL is also progressing because of the limit of representation power of in OWL language. The W3C suggests the SWRL(Semantic Web Rule Language) based on the combination of OWL and RuleML(Rule Markup Language), which is improved in the representation of rule. Thus, both OWL and SWRL are used for developing ontologies. However, research on inference of ontologies written in both languages is just begun. These day, for the inference of ontologies written in both languages, ontologies and divided in to two parts. The part written in OWL and written in SWRL. For the inference of the part written in OWL, Racer, a DL based inference engine, is used and for the other part Jess, a rule-based engine, is used. In this paper, we will propose three methods for integrated inference of the OWL part and the SWRL part of ontologies using Jess and some tools for ontology inference : OWLJessKB and SWRL Factory

• Journal of KIISE:Databases
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• v.37 no.2
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• pp.92-103
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• 2010

The Web Ontology Language (OWL) has become the W3C recommendation for publishing and sharing ontologies on the Semantic Web. To derive hidden information from OWL data, a number of OWL reasoners have been proposed. Since OWL reasoners are memory-based, they cannot handle large-sized OWL data. To overcome the scalability problem, RDBMS-based systems have been proposed. These systems store OWL data into a database and perform reasoning by incorporating the use of a database. However, they do not consider complete reasoning on all types of properties defined in OWL and the database schemas they use are ineffective for reasoning. In addition, they do not manage updates to the OWL data which can occur frequently in real applications. In this paper, we compare various database schemas used by RDBMS-based systems and propose an improved schema for efficient reasoning. Also, to support reasoning for all the types of properties defined in OWL, we propose a complete and efficient reasoning algorithm. Furthermore, we suggest efficient approaches to managing the updates that may occur on OWL data. Experimental results show that our schema has improved performance in OWL data storage and reasoning, and that our approaches to managing updates to OWL data are more efficient than the existing approaches.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.35-47
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• 2011

This paper proposes a set of rules to automatically generate OWL ontologies from relational databases. The purpose of the rules is to allow semantic access to existing RDB data without any database schema transformation and data migration process. In other words, the rules help a RDBMS play as a web ontology repository as well. However, the use of the mapping rules between RDB and OWL proposed by other studies for the objective causes troubles as follows. First, databases including the tables with a specific structure can't be translated into OWL. Second, the process for extracting an OWL individual unnecessarily lead to database join operations, or several SQL queries. On the other hand, our rules is designed to prevent these problems, can generate OWL classes and properties from database schemas and can generate OWL individuals from the database instances. In addition, an ontology generated by our rules is an OWL 2 DL ontology.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06c
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• pp.144-148
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• 2007

W3C에서 표준 온톨로지 언어로 OWL을 채택함에 따라 많은 온톨로지들이 OWL로 기술 및 구현되고 있다. 이에 따라 대용량의 OWL 문서를 효율적으로 저장하고, 검색할 수 있는 모델에 대한 필요성이 제기되고 있으며, Jena, $Prot{\acute{e}}g{\acute{e}}$, Sesame, FacT 등 다양한 프레임워크가 제안되어 활발히 연구가 진행되고 있다. 이 논문에서는 기본적인 Jena2의 저장소 모델이 단일 테이블에 문서의 정보를 저장하여 대용량의 OWL데이터의 처리에 있어 성능이 저하되는 문제점을 해결하여 대용량의 OWL 문서의 효율적인 저장, 관리, 질의 가능한 OWL 온톨로지 관계형 데이터베이스 모델을 제안한다. 또한 OWL 온톨로지 관계형 데이터베이스 모델을 위한 어댑터 및 컨버터를 제안한다.

• Journal of KIISE:Computing Practices and Letters
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• v.13 no.3
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• pp.179-192
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• 2007

Based on ontologies, semantic Web services enable the discovery, selection, and composition. OWL-S is a do facto standard ontology for describing semantics of Web services. Due to the difficulty of the OWL-S grammar, the teaming curve for constructing OWL-S description manually can be steep. This paper presents an efficient method for generating OWL-S descriptions from UML diagrams, which are widely used for software design and development. The proposed method is based on UML profiles to generate an OWL-S ontology from sequence or activity diagrams, which represent the behavior of a business process. Specifically, an XMI file extracted from UML diagrams is transformed into an OWL-S description via an XSLT script. Experimental results with a large volume of UML diagrams show that the proposed method deals with the control flow of complex processes and is superior to previous methods.

• The Journal of Korean Association of Computer Education
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• v.11 no.5
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• pp.77-88
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• 2008

Having observed the restriction of the current Web technology, the semantic Web has been developed, and it now has grown up with the core help of the W3C to a level where it recommends the OWL Web ontology language. Besides, in order to deduce the information out of OWL data, several inference systems have been developed such as Jena, Jess, and JTP. Unfortunately, however, quite few systems can effectively handle recently developed OWL data, and further, due to the limitation of file-based operation, the current inference systems cannot meet the requirements for handing huge OWL data. An efficient method for storing and searching ontology data is essential for ensuring stable information inference processes. In this study, firstly, we proposed a model based on the database management system to transform and store OWL data and to enable deduction process from the database. Secondly, we designed and implemented an effective OWL storing system based on our model. Finally, we compare our system with the previous inference systems through experimental performance analysis.

• Journal of the Korea Society of Computer and Information
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• v.14 no.1
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• pp.191-203
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• 2009

To provide dynamic services for users in ubiquitous computing environments by considering context in real-time, in our previous work we proposed Metaservice concept, the description specification and the process for building a Metaservice library. However, our previous process generates separated models - UML, OWL, OWL-S based models - from each step, so it did not provide the established method for translation between models. Moreover, it premises aid of experts in various ontology languages, ontology editing tools and the proposed Metaservice specification. In this paper, we design the translation process from domain ontology in OWL to Metaservice Library in OWL-S and develop a visual tool in order to enable non-experts to generate consistent models and to construct a Metaservice library. The purpose of the Metaservice Library translation process is to maintain consistency in all models and to automatically generate OWL-S code for Metaservice library by integrating existing OWL model and Metaservice model.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07b
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• pp.646-648
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• 2005

시맨틱 웹과 시맨틱 웹 서비스의 논리적 기반이 되는 온톨로지에 대한 연구가 활발히 진행되고 있다. W3C는 웹 온톨로지 기술을 위한 표준 언어로 OWL을 발표했고, OWL로 기술된 온톨로지는 웹 서비스, 유비쿼터스 컴퓨팅 등에서 활용되고 있다. 그러나 OWL의 복잡한 문법 구조는 OWL 온틀로지 개발을 어렵게 하고 있어, 직관적으로 OWL 온틀로지를 개발할 수 있는 방법이 요구되었고. 이를 위해 Protege 등 많은 온톨로지 편집기들이 개발되었다. 본 논문에서는 쉬운 OWL 온톨로지 편집을 위해 개체 중심의 온톨로지 시각화를 통한 온톨로지 편집기 개발에 관한 내용을 담고 있다. 이 편집기는 JDK 1.4 환경에서 개발되었으며 OWL 온톨로지 분석을 위해 Jena2 API를 사용하였다.

• The Journal of Society for e-Business Studies
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• v.9 no.3
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• pp.259-276
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• 2004

ebXML and Web Services provide UDDI and ebXML registry for storing and managing the business and Service information of companies, respectively. Recently, W3C have released the OWL(Web Ontology Language) to Recommendation, and OWL-S proposed to describe the semantics of Web Services using the OWL ontologies. In this paper, we compared the OWL-S with the registry information model(RIM) of ebXML and the data structure of UDDI, and directly connect ones, which that of ebXML similar to that of UDDI; we extend the structure of the OWL to connect the rests. Consequently, our system enables to construct the ontologies of services and discover their semantics by using the information stored in the registries, and tintegrate UDDI, ebXML registry and OWL-S registry. By using the extending OWL-S documents in our system, agents can utilize for the semantic matchmaking.