• Journal of KIISE:Databases
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• v.35 no.2
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• pp.155-168
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• 2008

This paper proposes a relational security model-based RDF Web ontology access control model. The Semantic Web is recognized as a next generation Web and RDF is a Web ontology description language to realize the Semantic Web. Much effort has been on the RDF and most research has been focused on the editor, storage, and inference engine. However, little attention has been given to the security issue, which is one of the most important requirements for information systems. Even though several researches on the RDF ontology security have been proposed, they have overhead to load all relevant data to memory and neglect the situation that most ontology storages are being developed based on relational database. This paper proposes a novel RDF Web ontology security model based on relational database to resolve the issues. The proposed security model provides high practicality and usability, and also we can easily make it stable owing to the stability of the relational database security model.

• Journal of KIISE:Databases
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• v.35 no.1
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• pp.29-43
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• 2008

Although RDF ontologies might be expressed in XML tree model, existing methods for protection of XML documents are not suitable for securing RDF ontologies. The graph style and inference feature of RDF demands a new security model development. Driven by this goal, this paper proposes a new query-oriented model for the RDF ontology access control. The proposed model rewrites a user query using a three-layered ontology view. The proposal resolves the problem that the existing approaches should generate inference models depending on inference rules. Accessible ontology concepts and instances which a user can visit are defined as ontology views, and the inference view defined for controling an inference query enables a controlled inference capability for the user. This paper defines the three-layered view and describes algorithms for query rewriting according to the views. An implemented prototype with its system architecture is shown. Finally, the experiment and comparative evaluation result of the proposal and the previous approach is described.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.2
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• pp.125-133
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• 2009

RDF is widely used as the ontology language for representing metadata on the semantic web. Since ontology models the real-world, ontology changes overtime. Thus, it is very important to detect and analyze changes in knowledge base system. Earlier studies on detecting changes between RDF models focused on the structural differences. Some techniques which reduce the size of the delta by considering the RDFS entailment rules have been introduced. However, inferencing with RDF models increases data size and upload time. In this paper, we propose a new change detection using RDF reasoning that only computes a small part of the implied triples using backward chaining strategy. We show that our approach efficiently detects changes through experiments with real-life RDF datasets.

• Journal of Intelligence and Information Systems
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• v.11 no.2
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• pp.31-45
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• 2005

In this paper, convert in RDF triple and a RDF document through RDF document converters and design metadata schema about a digital camcorder after use Wrapper technology, and acquiring commodity information of a HTML page about the digital camcorder which these papers are defined so as to be different by electronic commerce stores, and is expressed. Save in digital camcorder domain ontology storage that implemented to relational database to DCC knowledge base ontology as convert to OWL Web ontology based on designed metadata schema. Through compare with rdf and DCCKBO, mapping, and inference process, provide to buyers by DCC information of the store that had the commodity purchasing information which is the best, and proposed a dynamic Web ontology guessed to contents of the best commodity purchasing information, and to define domain ontology saved in DCCKBO.

• Proceedings of the Korean Society of Computer Information Conference
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• 2008.06a
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• pp.11-16
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• 2008

본 논문은 온톨로지(ontology) 작성에 사용되는 RDF(Resource Description Framework) 모델을 CPN(Colored Petri Net) 모델로 변환하여 표현하는 방법을 제안하고, 페트리 넷 시뮬레이션으로 RDF의 의미를 해석하여 RDF 질의문에 답할 수 있음을 보인다. 또한, 어떠한 RDF 모델도 CPN 모델로의 변환이 가능하다는 제안 방법의 완전성과 무결성을 소개하고, 제안한 방법으로 구축된 CPN 모델에서 RDF 질의에 대해 정확하게 결과를 구하는 방법을 제시한다.

• 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.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.2
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• pp.49-63
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• 2008

RDF is the base ontology model which is used in Semantic Web defined by W3C. OWL expands the RDF base model by providing various vocabularies for defining much more ontology relationships. Recently Jain and Farkas have suggested an RDF access control model based on RDF triple. Their research point is to introduce an authorization conflict problem by RDF inference which must be considered in RDF ontology data. Due to the problem, we cannot adopt XML access control model for RDF, although RDF is represented by XML. However, Jain and Farkas did not define the authorization propagation over the RDF upper/lower ontology concepts when an RDF authorization is specified. The reason why the authorization specification should be defined clearly is that finally, the authorizatin conflict is the problem between the authorization propagation in specifying an authorization and the authorization propagation in inferencing authorizations. In this article, first we define an RDF access authorization specification based on RDF triple in detail. Next, based on the definition, we analyze the authoriztion conflict problem by RDF inference in detail. Next, we briefly introduce a method which can quickly find an authorization conflict by using graph labeling techniques. This method is especially related with the subsumption relationship based inference. Finally, we present a comparison analysis with Jain and Farkas' study, and some experimental results showing the efficiency of the suggested conflict detection method.

• Proceedings of the Korea Society for Simulation Conference
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• 2005.11a
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• pp.180-184
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• 2005

These days, home network connects all home appliances using one of broadband convergence network, is constructed and propagated to more than 10 million house hold. Users can monitor and control statuses of home appliances using mobile terminal through homeserver. For active propagation of home network, high-quality multimedia service is very important. Specially, as digital recorder and digital camera is propagated, new paradigm that private DVDs can be shared in many household shows up. The homeserver is the main part of UbiHome, which can store much multimedia content and through which the user can search and share these contents. For searching and sharing, the metadata of contents is supposed to keep the consistency. These metadata include the description to different format such as Image, movie, and music. Therefore, we intend to provide a RDF model for effectively storing, searching and managing high-quality contents in UbiHome. In this paper, we propose to make Ontology to close semantic approach using RDF/RDF Schema for managing multimedia data in UbiHome. we propose RDF-Based Local Ontology and merging these ontology to RDF-Based Global Ontology.

• 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.

• 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.