• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.99-116
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• 2009

For the mapping of two dimensional table structures of relational databases to the hierarchical XML documents, we apply the foreign key relationships of relational databases. In other words, the primary key of another table referenced by a foreign key of one tuple is mapped to the parent of the foreign key. Then XML hierarchies with order are expressed. In addition, the XML view file generated by the foreign key mappings shows side effects in the case of the relational database update for the satisfaction of referential integrity constraint in the foreign key. Thus, by inferring the foreign key roles at the generation of XML hierarchies, we can anticipate where the side effects occur in the hierarchies. We keep the XML view files up-to-date by reflecting the side effects to the XML files at the update of the underlying relational databases.

• Journal of Korea Multimedia Society
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• v.9 no.8
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• pp.950-962
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• 2006

Recently, there have been increased many 3 dimensional graphic applications in Internet. Thus, a growing number of methods have been proposed for retrieving 3-D graphic data using their 3D features such as color, texture, shape, and spacial relations. However, few researches focus on 3D graphic modeling and database storage techniques. In this paper, we introduce a system that can store 3D graphics data modeled by XML-based 3D graphics markup language, 3DGML, and support content-based retrievals on 3D data by using SQL. We also present a mapping technique of 3DGML to relational database. The mapping process includes the extraction of semantic information from 3DGML and translate it into relational format. Finally, we show examples of SQL queries which use the 3D information contained in a 3D scene such as objects, 3D features, descriptions and scene-object component hierarchy.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.11a
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• pp.117-120
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• 2004

인터넷의 사용 증가로 정보의 양은 기하급수적으로 증가하고 있으며 웹 데이터의 표준인 XML의 데이터 표현의 유연성으로 인해 EDMS(Electronic Document Management Syste), ebXML(e-business extensible Markup Language)등 웹 기반의 전자문서를 이용하는 XML를 문서 교환 및 표준 문서 형식으로 도입하고 있는 실정이다. 이런 XML문서들을 저장관리 하기 위해 XML전용 Database도 현재 많이 연구되고 있다. 하지만 이런 XML전용 Database들은 관계형 데이터베이스보다 실용성이 떨어지는 점들이 많아 XML과 관계형 데이터베이스 매핑에 대한 연구도 활발히 진행중이다. 본 논문에서는 $C{\sharp}$을 이용하여 XML과 관계형 데이터베이스 간의 매핑을 위한 모듈을 개발하였으며, XML의 element와 관계형 데이터베이스의 필드를 상호 매핑시켜 줌으로 인해 XML문서의 element를 정확하게 저장, 관리 할 수 있다.

• Journal of Korea Multimedia Society
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• v.10 no.3
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• pp.289-302
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• 2007

The existing query processing technique for CXQuery, which is able to query regardless of knowledge about XML document structures, is difficult to manage because of table join for query processing and results return, mapping XML documents into relational tables, and so on. In this paper we have developed a converter capable of converting CXQuery to XQuery in order to make use of the query processing techniques for XQuery progressing standardization. The converting speed of the converter takes a trifling time as much as negligible quantities in comparison with the total query processing time. This is also able to query directly XML documents regardless of relational databases, and users can query without knowledge about XML document structures.

• Journal of KIISE:Databases
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• v.30 no.6
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• pp.641-650
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• 2003

The eXtensible Markup Language(XML) is emerging as a standard format of data representation and exchange on the Internet. There have been researches about storing and retrieving XML documents using the relational database which has techniques in full growth about large data processing, recovery, concurrency control and so on. Since in previous systems same structure information and fundamental operation are used for processing of various kinds of XML queries, only some specific query can be efficiently processed not all types of query. In this paper, we propose a flexible query processing system. To process query efficiently, the proposed system analyzes regular path expression queries, and uses $\theta$-join operation using region numbering values to check ancestor-descendent relationship and equi-join operation using parent's region start value to check parent-child relationship. Thus, the proposed system processes efficiently XML regular path expressions. From the experimental results, we show that proposed XML query processing system is more efficient than previous systems.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.1-9
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• 2009

Many techniques have been proposed to store efficiently and query XML data. One way achieving this goal is using relational database by transforming XML data into relational format. But most researches only transformed content and structure of XML schema. Although they transformed semantic constrainment of XML schema, they did not all of semantics. In this paper, we propose a systematic technique for extracting semantic constrainment from XML schema and storing method when the extracting result is transformed into relational schema without any lost of semantic constrainment. The transforming algorithm is used for extracting and storing semantic constrainment from XML schema and it shows how extracted information is stored according to schema notation. Also it provides semantic knowledges that are needed to be confirmed during the transformation to ensure a correct relation schema. The technique can reduce storage redundancy and can keep up content and structure with integrity constraints.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.5B
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• pp.482-490
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• 2004

Recently, XML has been emerging as a standard for storing and exchanging of data for various distributed applications based on the Internet. Since there are increasing demands to store and manage XML documents, a lot of research works are going on this area to develop new took and techniques based on the XHL. However, most of the researches are concentrated on mapping techniques based on instance or DTD, and the main focus is on structural transformation. Current trend of research is toward the usage of XML documents based on XML schema, and demands not only conversion of structure but also preservation of the semantic constraints. This paper sets up the using of DIDL standing on the basis of XML schema from MPEG-21 as an application domain, and proposes the mapping model that can preserve semantic constraints in addition. We expand previous research techniques in the preprocessing step for the specific domain, and then, apply various new mapping methods in the postprocessing step. We present and discuss the system architecture for implementation, and introduce the algorithms and present implementation environment and semantic extension methodology in detail. Finally we show actual table and query processing based on our proposal.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2001.11a
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• pp.169-171
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• 2001

본 논문에서는 XML(eXtensible Markup Language)을 위한 데이터 모델을 제시하기 위해 현재 광범위하게 사용되고 있는 관계형 데이터베이스(relational database) 개념을 적용한다. 관계형 데이터베이스는 업무 요구사항의 분석으로부터 고수준의 개념적 데이터 모델을 사용해서 데이터베이스에 대한 개념적 스키마(conceptual schema)를 생성한 다음, 고수준 개념적 데이터 모델을 구현 데이터 모델로 변환하여 논리적 데이터베이스 스키마를 생성한다. 이때, 고수준 개념적 데이터 모델링의 대표적인 방법으로 ER모델을 사용하고, 구현 데이터 모델로 관계 모델(relation model)을 사용한다. XML은 문서의 논리적 구조를 정의하는 DTD와 XML Schema 등을 갖는다. XML의 DTD와 정보 모델링 기법인 E/R 모델은 모두 작은 세계(real world)를 모델링하는 도구들이라고 할 수 있다. 본 논문에서는 XML의 DTD와 E/R 모델의 구성요소들을 분석하여 서로 사상(mapping)시키는 'XML을 위한 데이터 모델(A Data Model for XML)'을 제시한다. 최종적으로 제시된 XML을 위한 데이터 모델에 의해 작은 세계(real world)을 모델링하는 XML DTD에서 정의한 구조(XML Structure)을 따르는 유효한 XML문서(validate XML document)들은 관계형 데이터베이스에 저장할 수 있게 된다.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05c
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• pp.1539-1542
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• 2003

MPEG-21의 Digital Item은 표준으로 정해진 DID(Digital Item Declaration) 모델을 이용하여 표현된다. 해당 모델은 XML 스키마에 기반하여 정의된 것으로서 뛰어난 표현력과 확장성을 제공할 수 있다. 하지만 정의된 데이터의 저장이나 검색 및 기존 데이터와의 연계에 관한 언급은 표준에서 이루어지지 않고 있다. 본 연구에서는 MPEG-21에서 DID 모델을 이용하여 정의되어 있는 Digital Item을 관계형 데이터베이스에 저장하여 사용할 수 있는 방법에 관하여 논하고자 한다. DID를 이용하여 정의된 내용을 관계형 데이터베이스의 스키마로 매핑 하였으며, SQL 언어를 이용하여 기존 데이터와의 연동 검색을 지원하도록 설계하였다.