• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.999-1008
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• 2002

XML is emerging as a standard data format to exchange and to present data on the Web. There are increasing needs to efficiently store and to query XML data. In this paper. we propose a new schema transformation algorithm based on a common structure extracting technique from XML documents. The common structure is shared by all XML documents referenced by DTD and the uncommon structure is ununiformly appeared on all XML documents referenced by DTD. Based on the extracted common and uncommon structures, we transform XML DTD into relational database schema. We conduct a performance evaluation based on the number of the generated tables, the size of the record, query processing time and the number of joins on the query. The performance of our algorithm is compared with the existing algorithms, then in most cates, our algorithm is better than the existing ones with respect to the number of the generated tables and appearance of NULL values in the tables.

• Journal of the Korea Society of Computer and Information
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• v.16 no.3
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• pp.53-63
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• 2011

Many techniques have been proposed to store and query XML data efficiently. One way achieving this goal is using relational database by transforming XML data into relational format. It is important to transform schema to preserve the content, the structure and the constraints of the semantics information of the XML document. Especially, key constraints are an important part of database theory. Therefore, the proposal technique has considered the semantics of XML as expressed by primary keys and foreign keys. And, the proposal technique can preserve not only XML data constraints but also the content and the structure and the semantics of XML data thru transformation process. Transforming information is the content and the structure of the document(the parent-child relationship), the functional dependencies, semantics of the document as captured by XML key and keyref constraints. Because of XML schema transformation ensures that preserving semantic constraints, the advantages of these transformation techniques do not need to use the stored procedure or trigger which these data ensures data integrity in the relational database. In this paper, there is not chosen the ID/IDREF key which supported in DTD, the inheritance relationship, the implicit referential integrity.

• Journal of Korea Multimedia Society
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• v.7 no.1
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• pp.1-11
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• 2004

In this paper. we propose a storage system for XML documents using relational databases. Additional processing is required to store XML documents in the relational databases due to the discrepancy between XML structures and relational schema. This study aims to store XML documents with DTD in the relational databases. We propose the association inlining that exploits shred inlining and hybrid inlining and avoids relation fragments and excessive joins. Experiments show some improvements in the performance with the proposed method. The information of the storage structures is extracted from the simplified DTD. Existing map classes are extended in order to map various structures of XML to relational schema. Map classes are defined for various structures such as elements with multiple values, elements with multiple super elements, and elements with recursive structures through analyzing XML documents. Map files that are XML structures and used in generating SQL statements are created by using the extracted information of storage structures and map classes.

• Journal of Internet Computing and Services
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• v.8 no.2
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• pp.95-103
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• 2007

Many techniques have been proposed for mapping from XML to relations, but most techniques did not negotiate the semantics of XML data. The semantics is important to validate storage, query optimization, modification anomaly in process of schema design. Specially, functional dependencies are an important part of database theory, also it is basis of normalization for relational table in BCNF. This paper propose a new technique that reflect functional dependencies to store relation mapped from XML based on XML Schema. The technique can reduce storage redundancy and can keep up content and structure with constraint described by functional dependencies.

• Journal of Korea Multimedia Society
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• v.12 no.7
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• pp.1022-1031
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• 2009

In this paper, we propose a researcher modeling technique based on ontology and construct social network for researchers using diverse relational properties. User ontology schema is created by extending the existing HR-XML model for a researcher model. User ontology schema and instance are created by OWL. We compose social network model for efficient cooperation between researchers using static relational properties such as educational background and dynamic relational properties such as co-authors and co-workers, etc. Closeness has direction because researcher network is differently configured by the researchers. We define inferencing rules using SWRL and inference ontology rules using racer inference machine to compose direct relationships between researchers. The proposed model for researchers can be applied to the cooperation model for researchers by retrieving common expert group dynamically.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.20-28
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• 2000

In distributed data processing environments, heterogeneous data sources should corporate each other. The CORBA standards proposed by OMG solve this problem by the integration of platform independent applications. In this paper, we design and implement a CASE tool that help linking CORBA applications to relational databases by interface method. This CASE tool manipulates the database schema and generates IDL and $C^{++}$ stubs corresponding to the schema. We explain the code generation process and evaluate the data access performance of the interface method compared to adapter method and various implementation languages. The implemented tool can be used for developing applications that need relational database corporation environments such as distributed information systems or data warehousing. etc.

• 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.

• The KIPS Transactions:PartD
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• v.9D no.6
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• pp.1105-1112
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• 2002

Nowadays the information exchange based on XML such as B2B electronic commerce is spreading. Therefore a systematic and stable management mechanism for storing the exchanged information is needed. For this goal there are many research activities for concerning the connection between XML application and relational databases. But because XML data has hierarchical structure and relational databases can store only flat-structured data, we need to make a conversion rule which changes the hierarchical architecture to a 2-dimensional format. Accordingly the modeling methodology for storing such structured information in relational databases is needed. In order to build good quality application systems, modeling is an important first step. In 1997, the OMG adopted the UML as its standard modeling language. Since industry has warmly embraced UML, its popularity should become more important in the future. So a design methodology based on UML is needed to develop efficient XML applications. In this paper, we propose a unified design methodology for XML applications based on relational database using UML. To reach these goals, first we introduce a XML modeling methodology to design W3C XML schema using UML and second we propose data modeling methodology for relational database schema to store XML data efficiently in relational databases.

• Journal of the Korean School Mathematics Society
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• v.8 no.2
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• pp.273-289
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• 2005

This research was implemented to know how mathematics education is performed both in a school and in the private institute based on Skemp' Theory that strongly takes an emphasis on understanding of mathematics principle. On this study, I compare the method of a teacher in a school with in a private institute accompanying the analysis of textbook in teaching. The results are the followings: First, textbooks used in a school and an institute are not helpful for relational understanding of students, and the textbook used in school was more suitable for students than that in institute. Second, in the case of teaching methods, school teacher has focused more relational schema with the students than an private institute institutor, As we said, in school mathematics education is implemented focusing on the understanding of mathematics. According to this, students should to trust public education more than private institute in constructing schema in mathematics learning.

• Journal of the Korean School Mathematics Society
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• v.18 no.4
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• pp.353-370
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• 2015

This study was conducted as a qualitative case study that explored how gifted 3rd-grade elementary school children who had learned the primary concepts of division and fraction, when they studied contents about decimal, formed the transformed primary concept and transformed schema of decimal by the learning of accurate primary concepts and connecting the concepts. That is, this study investigated how the subjects attained relational understanding of decimal based on the primary concepts of division and fraction, and how they formed a transformed primary concept based on the primary concept of decimal and carried out vertical mathematizing. According to the findings of this study, transformed primary concepts formed through the learning of accurate primary concepts, and schemas and transformed schemas built through the connection of the concepts played as crucial factors for the children's relational understanding of decimal and their vertical mathematizing.