• Journal of KIISE:Databases
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• v.36 no.6
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• pp.422-433
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• 2009

As an effort to secure Semantic Web, in this paper, we introduce an RDF access authorization model based on an ontology hierarchy and an RDF triple pattern. In addition, we apply the authorization model to RDF query validation for approved access authorizations. A subscribed SPARQL or RQL query, which has RDF triple patterns, can be denied or granted according to the corresponding access authorizations which have an RDF triple pattern. In order to efficiently perform the query validation process, we first analyze some primary authorization conflict conditions under RDF subsumption inference, and then we introduce an efficient query validation algorithm using the conflict conditions and Dewey graph labeling technique. Through experiments, we also show that the proposed validation algorithm provides a reasonable validation time and when data and authorizations increase it has scalability.

• Journal of the Korea Society of Computer and Information
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• v.25 no.10
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• pp.23-34
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• 2020

In this paper, we proposes a method to automatically construct SHACL schemas for RDF knowledge graphs(KGs) generated by Direct Mapping(DM). DM and SHACL are all W3C recommendations. DM consists of rules to transform the data in an RDB into an RDF graph. SHACL is a language to describe and validate the structure of RDF graphs. The proposed method automatically translates the integrity constraints as well as the structure information in an RDB schema into SHACL. Thus, our SHACL schemas are able to check integrity instead of RDBMSs. This is a consideration to assure database consistency even when RDBs are served as virtual RDF KGs. We tested our results on 24 DM test cases, published by W3C. It was shown that they are effective in describing and validating RDF KGs.

• The KIPS Transactions:PartB
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• v.11B no.5
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• pp.619-624
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• 2004

The quantity of business information like to be shared enterprise information and business catalog quickly increased because of activating e-commerce. Necessary of metadata management which is using RDF was required. RDF metadata management does not have to be restricted by RDF/RDFS knowledges, has to describe web resources and has to support metadata validation. But research which supports this is not enough. In this paper we enable to create and manage RDF/RDFS document using various interfaces, change from metadata to N-Triple and verify metadata validation.

• Journal of the Korea Society of Computer and Information
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• v.25 no.8
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• pp.9-21
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• 2020

With the proliferation of RDF knowledge graphs(KGs), there arose a need of a standardized schema representation of the graph model for effective data interchangeability and interoperability. The need resulted in the development of SHACL specification to describe and validate RDF graph's structure by W3C. Relational databases(RDBs) are one of major sources for acquiring structured knowledge. The standard for automatic generation of RDF KGs from RDBs is R2RML, which is also developed by W3C. Since R2RML is designed to generate only RDF data graphs from RDBs, additional manual tasks are required to create the schemas for the graphs. In this paper we propose an approach to automatically generate SHACL schemas for RDF KGs populated by R2RML mappings. The key of our approach is that the SHACL shemas are built only from R2RML documents. We describe an implementation of our appraoch. Then, we show the validity of our approach with R2RML test cases designed by W3C.

• Proceedings of the Korea Multimedia Society Conference
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• 2004.05a
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• pp.447-450
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• 2004

인터넷의 보급으로 인해 수많은 데이터가 생성되고 있고 이러한 데이터를 효율적으로 관리하고자 메타데이타 표준이 수차례에 걸쳐 발표되었다. 그러나 기존 발표된 표준들은 데이터 관리를 위해 특정 도메인에 제한적이거나 너무 광범위하여 효율적이지 못하다는 문제를 가지고 있다. 또한 표준에 따라 생성된 메타데이타라 할지라도 유효성을 검증하지 못하기 때문에 정확한 메타데이타로 정의내릴 수 없는 실정이다. 따라서 본 논문에서는 RDF(Resource Description Framework)에 기초하여 메타데이타를 효율적으로 저작할 수 있는 저작 기능, 생성된 메타데이타에 대한 유효성 검증이 가능한 유효성 검증 기능, 메타데이타의 N-Triple 표현을 지원하고 생성할 수 있는 N-Triple Generator를 지원할 수 있는 RDF 기반 저작 틀을 개발하였다.

• Journal of the Korea Society of Computer and Information
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• v.27 no.11
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• pp.67-80
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• 2022

In this paper, we propose a system which automatically generates the ShEx schemas to describe and validate RDF knowledge graphs constructed by RML mapping. ShEx schemas consist of constraints. The proposed system generates most of the constraints by converting the RML mapping rules. The schemas consisting only of constraints obtained from mapping rules can help users to figure out the structure of the graphs generated by RML mapping, but they are not sufficient for sophisticated validation purposes. For users who need a schema for validation, the proposed system is also able to provide the schema with added constraints generated from metadata extracted from the input data sources for RML mapping. The proposed system has the ability to handle CSV, XML, JSON or RDBMS as input data sources. Testing results from 297 cases show that the proposed system can be applied for RDF graph validation in various practical cases.

• Proceedings of the CALSEC Conference
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• 2003.09a
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• pp.211-217
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• 2003

웹의 보편화로 인하여 수많은 데이터가 산출되고 있으나 데이터 관리를 위한 메타데이터 표준은 특정 도메인에 제한적이고 너무 광범위하게 정의되어 있어 데이터가 비효율적으로 관리되고 있는 실정이다. 이를 해결하기 위해 RDF를 활용하여 자원간의 관계를 정의하고 있으나, RDF의 특성에 적합한 편집도구가 전무한 상태이다. 따라서 본 논문에서는 RDF 저작도구를 설계 및 구현함으로써 RDF를 기반으로 메타데이터의 유효성 검증을 수행하고, 기술된 자원간의 관계를 가시적으로 분석할 수 있는 노드 앤 아크 다이어그램을 지원하며, 웹자원을 N-triple로 표현하여 데이터의 효율적인 관리 및 분석을 가능하게 하였다.

• Journal of the Korea Society of Computer and Information
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• v.27 no.9
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• pp.77-89
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• 2022

In this paper, we propose a system which automatically generates SHACL schemas to describe and validate RDF knowledge graphs constructed by RML mappings. Unlike existing studies, the proposed system generates the schemas based on not only RML mapping rules but also metadata extracted from RML mapping input data in various formats such as CSV, JSON, XML or databases. Therefore, our schemas include the constraints on data type, string length, value range and cardinality, which were not present in the existing schemas. And we solves the problem with "repeated properties" which overlooked in existing studies. Through a conformance test consisting of 297 cases, we show that the proposed system generates correct constraints for the graphs. The proposed system can contribute to automation of the tedious and error-prone existing manual validation processes.

• Journal of Convergence for Information Technology
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• v.10 no.1
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• pp.139-148
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• 2020

As the internet and computer technology are developed, there is a need for service of traditional culture that can effectively search and create culture, history, and tradition-related materials in online contents. In this paper, we developed an RDF-based ontology retrieval service platform and verified usability and validity. This platform is divided into triple search, keyword search, network graph search, story search and management, curation management module. Based on this, the search results can be visualized based on the relationship between data, network graph search and story search can be used to easily understand the relationship between the keywords. An platform evaluation was conducted for verification, and it was evaluated that an intelligent search that can easily identify the relationship between information and shorten the analysis and search time than the existing search function.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.2231-2234
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• 2002

정보 인프라의 확장과 더불어 웹 이용의 보편화로 인해 오프라인(off-line)과 온라인(on-line)상에는 많은 데이터가 산출되고 있는 상황이다. 그러나 데이터 관리를 위한 메타데이타 표준이 특정 도메인(domain)에 제한적이거나 너무 광범위하게 정의되어 있기 때문에 효율적인 데이터 관리가 되지 못하고있다. 또한 생성한 메타데이타에 대한 유효성 검증이 되지 않으므로 정확한 메타데이타인지를 보장할 수 없는 실정이다. 따라서 본 논문에서는 메타데이타에 대한 유효성 검증을 수행하고, RDF(Resource Description Framework)를 기반으로 메타데이타를 효율적으로 저작할 수 있는 저작 툴과 웹 자원(resource)를 N-triple로 표현하여 데이터를 관리할 수 있는 N-triple 생성기를 개발하였다.