• Journal of Digital Contents Society
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• v.9 no.2
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• pp.285-293
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• 2008

In Semantic Web, metadata and ontology for representing semantics and conceptual relationships of information resources are essential factors. RDF and RDF Schema are W3C standard models for describing metadata and ontology. Therefore, many studies to store and retrieve RDF and RDF Schema documents are required. In this paper, we focus on some results of analyzing available query patterns considering both RDF and RDF Schema and classify queries on RDF and RDF Schema into the three patterns. RDF and RDF Schema can be represented as graph models. So, we proposed some strategies to store and retrieve using the graph models of RDF and RDF Schema. We can retrieve entities that can be arrived from a certain class or property in RDF and RDF Schema without a loss of performance on account of multiple joins with tables.

• Journal of the Korean Society for information Management
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• v.17 no.1
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• pp.21-47
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• 2000

Keeping the semantic interoperability between different formats is very important for reuseing and consistently processing metadata. This article is to design common schema and KORMARC schema based on RDF schema. For this, common elements are made by comparison of Dublin Core elements and KORMARC fields. The schema of these elements is designed for construction of semantic interoperability, basing RDF schema specification and syntax specification. Eventually, the semantic interoperability between a number of metadata formats can be constructed by matching the common elements to each attribute of format. KORMARC schema is designed by the application of common schema.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.29-40
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• 2000

With increasing amounts of information on the web and needs to access accurately them, it is very important to standardize metadata and to store and manage system. The RDF(Rdsource Description Framework) is a framework for representing exchanging, and reusing metadata. And, it can be processing uniformly the standardized metadata, because it uses XML(eXtensible Markup Language) syntax. The RDF schema provides a basic type system for use RDF models. In this paper, we propose rules and an algorithm to convert the RDF schema into an UML(Unified Modeling Language) class diagram and formal models to represent an object-oriented schema for the RDF schema. The proposed rules and algorithm are useful for natural mapping and the object modeling of RDF schema can be easily converted into the object-oriented schema, and the formal models supports an efficient environment for retrieving and processing object-oriented documents.

• Journal of the Korean Society for information Management
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• v.20 no.3
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• pp.241-259
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• 2003

The Basic Semantic Register(BSR) is and official ISO register designed for interoperability among eBusiness and EDI systems. The entities registered in the current BSR are not defined in a machine-understandable way, which renders automatic extraction of structural and relationship information from the register impossible. The purpose of this study is to offer a framework for designing an ontology that can provide semantic interoperability among BSR-based systems by defining data structures and relationships with RDF and OWL, similar meaning by the 'equivalentClass' construct in OWL, the hierachical relationships among classes by the 'subClassOf' construct in RDF schema, definition of any entities in BSR by the 'label' construct in RDF schema, specification of usage guidelines by the 'comment' construct in RDF schema, assignment of classes to BSU's by the 'domain' construct in RDF schema, specification of data types of BSU's by the 'range' construct in RDF schema. Hierarchical relationships among properties in BSR can be expressed using the 'subPropertyOf' in RDF schema. Progress in semantic interoperability can be expected among BSR-based systems through applications of semantic web technology suggested in this study.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.33-43
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• 2018

In this paper, we propose a method to automatically generate the description of an RDF graph structure. The description is expressed in Shape Expression Language (ShEx), which is developed by W3C and provides the syntax for describing the structure of RDF data. The RDF graphs to which this method can be applied are limited to those generated by the direct mapping, which is an algorithm for transforming relational data into RDF by W3C. A relational database consists of its schema including integrity constraints and its instance data. While the instance data can have been published in RDF by some standard methods such as the direct mapping, the translation of the schema has been missing so far. Unlike the users on relational databases, the ones on RDF datasets were forced to write repeated vague SPARQL queries over the datasets to acquire the exact results. This is because the schema for RDF data has not been provided to the users. The ShEx documents generated by our method can be referred as the schema on writing SPARQL queries. They also can validate data on RDF graph update operations with ShEx validators. In other words, they can work as the integrity constraints in relational databases.

• Journal of the Korea Society of Computer and Information
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• v.23 no.10
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• pp.45-55
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• 2018

R2RML is a W3C standard language that defines how to expose the relational data as RDF triples. The output from an R2RML mapping is only an RDF dataset. By definition, the dataset has no schema. The lack of schema makes the dataset in linked data portal impractical for integrating and analyzing data. To address this issue, we propose an approach for generating automatically schemas for RDF graphs populated by R2RML mappings. More precisely, we represent the schema using ShEx, which is a language for validating and describing RDF. Our approach allows to generate ShEx schemas as well as RDF datasets from R2RML mappings. Our ShEx schema can provide benefits for both data providers and ordinary users. Data providers can verify and guarantee the structural integrity of the dataset against the schema. Users can write SPARQL queries efficiently by referring to the schema. In this paper, we describe data structures and algorithms of the system to derive ShEx documents from R2RML documents and presents a brief demonstration regarding its proper use.

• Journal of the Korea Society of Computer and Information
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• v.12 no.1 s.45
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• pp.9-15
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• 2007

As the information of the internet increased, importance of sematic web for collecting and integration of these informations to support decision making of some group or ordinary people are growing as well. Basis structure that composes semantic web is ontology and languages like XML, RDF/RDF schema and OWL are basis means that compose ontology schema. When composes and manages Ontology schema, one of the important consideration point is that schema is changed as times go by. Therefore, change of domain of schema, change of data concept or change of relation between resource etc. are reflected in the ontology system. In this study, we suggest semantic web schema management skill in terms of version management. We categorized version change forms and created version graph for checking of version transition. With created version graph, we define transitivity rule and propose schema tag for detail application which enables extending of applicable version schema.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10d
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• pp.289-291
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• 2002

본 논문에서는 객체지향 패러다임의 구조적 특성을 적용하여 만든 시소러스를 이용하여 웹 자원의 의미적 연관성을 RDF 형식으로 표현할 수 있는 RDF 문서 자동 생성기를 소개한다. 객체지향 시소러스를 RDF 형식으로 나타내기 위해 시소러스에 사용된 객체와 관계의 내용을 명세한 네임 스페이스를 정의하여 시맨틱 웹에서 메타데이타를 기술하는 표준이 되는 RDF와 RDF Schema 형식으로 매핑할 수 있다. 이러한 연구를 통해 객체지향 시소러스의 내용을 RDF 형식으로 표현함으로써 지식베이스(KnowledgeBase)라 불리는 온톨로지를 생성할 수 있으며, 구축된 온톨로지는 시맨틱 웹 상의 에이전트나 다른 어플리케이션에 응용될 수 있다.

• Journal of Korean Library and Information Science Society
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• v.48 no.3
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• pp.233-257
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• 2017

In this paper, we propose an effective method to convert and construct the MEDLINE, the world's largest biomedical bibliographic database, into linked data. To do this, we first derive the appropriate RDF schema by analyzing the MEDLINE record structure in detail, and convert each record into a valid RDF file in the derived schema. We apply the dual batch registration method to streamline the subject URI duplication checking procedure when merging all RDF files in the converted record unit and storing it in a single RDF triple storage. By applying this method, the number of RDF triple storage accesses for the subject URI duplication is reduced from 26,597,850 to 2,400, compared with the sequential configuration of linked data in units of RDF files. Therefore, it is expected that the result of this study will provide an important opportunity to eliminate the inefficiency in converting large volume bibliographic record sets into linked data, and to secure promptness and timeliness.

• Journal of the Korean Society for information Management
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• v.17 no.3
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• pp.147-170
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• 2000

RDF treats all resources independently, that's integrated description model for internet resources description, that provides the model to connect resources that related with the specific resources. This article performs theoretical review of RDF model and syntax specification and RDF schema specification that's a common rule of semanics, structure and syntax those provides search and access in the area of dispersed information environment of internet and Dublin Core that's description element for build metadata. And with this way it's materialized metadata design, schema, DTD of Dublin Core element for building RDF-based metadata that is XML application.