• Journal of KIISE:Databases
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• v.34 no.3
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• pp.206-216
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• 2007

With respect to the Semantic Web proposed to overcome the limitation of the Web, OWL has been recommended as the ontology language used to give a well-defined meaning to diverse data. OWL is the representative ontology language suggested by W3C. An efficient retrieval of OWL data requires a well-constructed storage schema. In this paper, we propose a storage schema construction technique which supports more efficient query processing. A retrieval technique corresponding to the proposed storage schema is also introduced. OWL data includes inheritance information of classes and properties. When OWL data is extracted, hierarchy information should be considered. For this reason, an additional XML document is created to preserve hierarchy information and stored in an XML database system. An existing numbering scheme is utilized to extract ancestor/descendent relationships, and order information of nodes is added as attribute values of elements in an XML document. Thus, it is possible to retrieve subclasses and subproperties fast and easily. The improved query performance from experiments shows the effectiveness of the proposed storage schema construction and retrieval method.

• Journal of KIISE:Databases
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• v.35 no.3
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• pp.243-256
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• 2008

With rapid growth of Internet, the amount of information in the Web is increasing exponentially. However, information on the current Web is understandable only for human, and thus it makes the exact information retrieval difficult. For solving this problem, the Semantic Web is suggested and we must use ontology languages that can endow data to semantics for implementing it. One of the representative ontology languages is OWL(Web Ontology Language) adopted as a recommendation by the World-Wide Web Consortium. OWL has richer expression power and formal semantics than other ontology languages such as RDF and RDF-S. In addition, OWL includes hierarchical structure information between classes or properties. Therefore, an efficient OWL storage model considering hierarchical structure for effective information retrieval on the Semantic Web is required. In this paper, we suggest the XPOS(XPath-based OWL Storage) model including hierarchy information between classes or properties as XPath form and enabling intuitive and effective information retrieval. Also, we show the comparative evaluation results on the performance of XPOS model, Sesame, and the XML storage-based storage model regarding query processing.

• Journal of the Korea Computer Industry Society
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• v.7 no.3
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• pp.227-236
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• 2006

Semantic Web is getting popular to next web environment. Additionally, ontology language research is also activating to represent semantic relation of resource in semantic web. Specially, Ontology language as RDF and DAML+OIL appear on start point of research. But Ontology Language limited to describing characters of resource and to making a clear definition of relation of resource. So W3C suggest OWL at the next standard language for describing resource. OWL supply the lack of representation for RDF and RDF Schema. In this paper, we make Ontology to implement Online Retrieval System using OWL and propose the structure of storing Ontology document at the RDB. The structure support characters of OWL that are equivalent relationship, heterogeneous relationship, inverse relationship, union relationship and one of relationship between classes or properties. In this paper, we classify the extended elements for OWL from RDF Schema. And we propose the method of storing OWL using RDB for interoperability with many applications based on RDB. Finally, implement the storage and retrieval system based on OWL to provide advanced search function.

• Journal of Information Processing Systems
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• v.4 no.2
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• pp.61-66
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• 2008

In recent years, numerous studies have been attempted to exploit ontology in the area of ubiquitous computing. Especially, some kinds of ontologies written in OWL are proposed for major issues in ubiquitous computing such like context-awareness. OWL is recommended by W3C as a descriptive language for representing ontology with rich vocabularies. However, developers struggle to design ontology using OWL, because of the complex syntax of OWL. The research for OWL visualization aims to overcome this problem, but most of the existing approaches unfortunately do not provide efficient interface to visualize OWL ontology. Moreover, as the size of ontology grows bigger, each class and relation are difficult to represent on the editing window due to the small size limitation of screen. In this paper, we present OWL visualization scheme that supports class information in detail. This scheme is based on concept of social network, and we implement OWL visualization plug-in on $Prot{\acute{e}}g{\acute{e}}$ that is the most famous ontology editor.

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.269-277
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• 2007

Web service is an important technology to develop business to business e-commerce application. From a business perspective of time to market, dynamic evolution offers flexibility that software can adapt to unforeseen and fluctuating business requirements. OWL-S, based on OWL, is a service ontology language. The semantics provided by OWL support automation of service discovery, invocation, and service composition. In this paper we propose a framework to support dynamic evolution of service-oriented applications. We extend use-case analysis method to derive service description by defining requirements concept and mapping from requirement concept to activity diagram. A prototype is provided to show the validity of this framework.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.214-219
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• 2007

생성 규칙(Production Rule)과 이를 기반으로 하는 규칙 엔진(Rule Engine)을 기반으로 한 OWL 추론 엔진은 메타 규칙((Meta Rule)에 의존해 왔다. 메타 규칙은 OWL의 의미론 (Semantics)을 표현하기 용이하여 보다 손쉽게 OWL 추론 엔진을 구현할 수 있다는 장점을 제공하였으나 OWL 추론 성능에 있어 추론 속도와 대용량 온톨로지 처리 측면에서 모두 만족할 만한 성과를 얻지 못하였다. 본 논문은 DLP(Description Logic Programming)의 번역 접근법을 기반으로 한 번역 규칙(Translation Rules)을 메타 규칙과 혼용하는 OWL 추론 기법을 소개한다. LUBM 벤치마크를 통해 이 기법이 메타 규칙만을 이용했을 때 보다 100% 이상 추론 성능을 향상시켰을 뿐 아니라 메모리 사용량도 대폭 축소시켰음을 확인할 수 있었다. 또한, 번역을 통해 제한없는 차수 제약(Cardinality Restriction) 관련 추론을 지원하는 등 보다 넓은 범위의 OWL 추론을 지원할 수 있다.

• Korean Journal of Oriental Medicine
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• v.12 no.1
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• pp.1-12
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• 2006

Recently according to the WIPO's policy of preserving traditional knowledge, constructing the database of traditional knowledge is in progress. To maximize the retrieving power of the knowledge resource systems which will be developed later, it is necessary to construct the ontology for the concepts used by traditional knowledge. In order to construct the ontology systematically, a standardized ontology representation method is needed, and OWL(Web Ontology Language) is the recommendation of W3C(World Wide Web Consortium) and is widely used. Ontology tools can be used to ease the construction of OWL ontology, but no research about the comparison of OWL ontology tools exists. This paper compares the tools of OWL by an objective point of view and with that one can make a decision of using the appropriate tool for constructing OWL ontologies.

• Journal of the Korea Society of Computer and Information
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• v.15 no.1
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• pp.31-42
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• 2010

GPM(Generic Product Model) developed by Hitachi in Japan is a common data model to integrate and share life cycle data of nuclear power plants. GPM consists of GPM core model, an abstract model, implementation language for the model and reference library written in the language. GPM core model has a feature that it can construct a semantic network model consisting of relationships among objects. Initial GPM developed and provided GPML as an implementation language to support the feature of the core model, but afterwards the GPML was replaced by GPM-XML based on XML to achieve data interoperability with heterogeneous applications accessing a GPM data model. However, data models written in GPM-XML are insufficient to be used as a semantic network model for lack of studies which support GPM-XML and enable the models to be used as a semantic network model. This paper proposes OWL as the implementation language for GPM core model because OWL can describe ontologies similar to semantic network models and has an abundant supply of technical standards and supporting tools. Also, OWL which can be expressed in terms of RDF/XML based on XML guarantees data interoperability. This paper uses OWL DL, one of three sublanguages of OWL, because it can guarantee complete reasoning and the maximum expressiveness at the same time. The contents of this paper introduce the way how to overcome the difference between GPM and OWL DL, and, base on this way, describe how to convert the reference library written in GPML into ontologies based on OWL DL written in RDF/XML.

• The Journal of Society for e-Business Studies
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• v.10 no.3
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• pp.21-36
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• 2005

Current web search includes a lot of different results with information that user does not want, because it searches information using keyword mapping. Ontology can describe the correct meaning of web resource and relationships between web resources. And we can extract suitable information that user wants using Ontology Accordingly, we need the ontology to represent knowledge. W3C announced OWL(Web Ontology Language), meaning description technology for such web resource. However, the development of a special tool that can effectively compose and edit OWL is inactive. In this paper, we designed and developed an OWL authoring system that can effectively provide the generation and edit about OWL.

• Journal of KIISE:Databases
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• v.32 no.6
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• pp.585-592
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• 2005

The Semantic Web is being studied as the next step in the evolution of the web. In the environment of the Semantic Web, the information must be understandable computers as well as a just human. So we use ontologies for describing the contents of the web resources. Among such ontologies, OWL is proposed as a recommendation by W3C. OWL data is represented as graph structure and the query is evaluated by traversing each node of the graph. In this paper, we propose the optimization technique based on signature to efficiently process the OWL data. Our approach minimizes traversing each node of the graph in query processing.