• Proceedings of the Korea Multimedia Society Conference
• /
• 2002.11b
• /
• pp.343-346
• /
• 2002

관계데이터베이스를 이용한 XML 데이터저장방법에서 데이터가 삽입, 삭제, 갱신될 경우 인덱스를 제정의해야 하는 부담을 줄여주는 인덱스 기법을 제안한다. XML 데이터를 블록과 블록사이에 많아야 하나의 관계가 유지되도록 블록단위로 나누어 각 블록에 대해 Numbering 스킴을 적용하여 인덱스를 정의한다. 또한 정의된 인덱스를 이용하여 XML 질의 처리하기 Parent-Child Block Merge Algorithm과 Ancestor-Descendent Block Merge Algorithm을 제안한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10b
• /
• pp.148-150
• /
• 2004

XML(1)이 인터넷 상의 메시지 교환 형식으로 활발히 이용되면서, XML을 이용하는 많은 응용에서는 이를 효율적으로 관리하기 위한 방법이 요구되었다. 이러한 요구에 발 맞추어 현재, XML 데이터의 관리를 위한 많은 연구(3, 4, 5, 6, 7, 8, 9)가 진행 중에 있으나 아직까지는 어떤 방법이 XML 데이터의 관리를 위해 최적의 방법이라는 결론은 없는 실정이다 또한, 이러한 방법들을 실제 응용에 적용하기 위해서는 시스템 관리자가 XML 문서의 특성을 파악하고, 이를 기반으로 XML 데이터의 관리를 위해서 필요한 모든 모듈들을 개별적으로 개발하고 관리해야 한다. 이와 같은 방법은 응용의 측면에서 추가적인 비용과 노력을 추가해야 하는 부담이 발생한다. 본 논문에서는 앞서 언급한 요구사항들을 해결하기 위하여 고려하여 XML Schema to Relational Database Schema (XMLStoDBS)라는 XML문서를 제안하고, 이를 이용하여 응용에서 필요한 XML 데이터 관리 시스템을 자동으로 생성하기 위한 방법을 제안한다. XMLStoDBS는 응용에서 사용하고자 하는 XML Schema또는 DTD의 정보와 실제 데이터가 저장될 데이터베이스의 정보, 이 둘간의 사상관계를 표현하는 문서이다. 우리의 XMLStoDBS는 사용자가 응용에서 사용하고자 하는 XML Schema/DTD의 입력만으로 자동으로 생성되며, 응용에서는 이를 이용하여 응용에 필요한 XML 데이터 관리 시스템을 자동으로 생성할 수 있다.

• Journal of KIISE:Databases
• /
• v.34 no.6
• /
• pp.564-571
• /
• 2007

One of the methods for integrating XML data in distributed environments is using XML view. User can query toward distributed local XML views by using global XQuery queries in XQuery which is a standard query language for searching XML data. The global XQuery queries naturally contain join operations because of integrating and searching distributed heterogeneous data. Since join operations are generally expensive for processing a query, its processing technique is very important for efficient processing of global XQuery queries. Therefore there are some studies on the efficient processing of join operations and one of these studies is that selects minimum join cost by estimating a join selectivity. In case of SQL, there are already some researches for estimating a join selectivity and join cost of global SQL queries. However we can not apply their methods for estimating the selectivity of join operations in SQL queries into XQuery queries because of the structural difference between relational data and XML data. Therefore this paper proposes a method for estimating a selectivity of join operations in XQuery queries using the information of XML views. Our contribution is three threefold. First, we define the difference point for estimating join selectivity between SQL and XQuery. Second, we estimate join selectivity in XQuery queries by referring XML views. Third, we evaluate our estimating method.

• The KIPS Transactions:PartA
• /
• v.12A no.1 s.91
• /
• pp.31-40
• /
• 2005

In this paper, we propose XMDR(XML Metadata Registry) to guarantee the interoperability of data in distributed database, and describe a data synchronizing agent system using it. The proposal of XMDR is to solve the data heterogeneity problem in the sharing and exchanging data. Data heterogeneity problem is generated by different definition or mismatching expression of the same information. Therefore, we define XMDR with XML document by analyzing data elements based on MDR specification. The proposed synchronizing agent system using XMDR not only solves data heterogeneity for data interoperability in synchronizing data but also provides more efficient the agent system by offering errors of low frequency in the number of systems and requests of synchronizing data.

• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.15 no.4
• /
• pp.29-38
• /
• 2006

As the complexity of engineering design environment has been increased, it becomes difficult to exchange design data among design support systems. The purpose of this paper is to develop the XML-based Generalized Mechanical Data Exchange Formats(GMDEF) independent of specific mechanical element and to improve the interoperability of them using ontology, in order to integrate diverse design data and facilitate communication between design support systems. GMDEF consists of PartDoc and AssemblyDoc. PartDoc represents the information of a single part. AssemblyDoc represents the relation of parts composing an assembly. GMDEF is validated by GMDEF Schema. GMDEF Schema consists of separated XML Schemas and has flexible architecture to facilitate extension. The ontology is applied to GMDEF Schema to share and reuse vocabularies of specific mechanical elements.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2004.10a
• /
• pp.78-85
• /
• 2004

As the complexity of engineering design environment has increased, it is difficult to exchange design data among design support systems. The purpose of this paper is to develop the XML-based Generalized Mechanical Data Exchange Formats(GMDEF) independent of specific mechanical element and improve the interoperability of them using ontology, in order to integrate diverse design data and facilitate communication between design support systems. GMDEF consists of PartDoc and AssemblyDoc. PartDoc represents the information of a single part. AssemblyDoc represents the relation of parts constituting an assembly. GMDEF is validated by GMDEF Schema. GMDEF Schema consists of separated XML Schemas and has flexible architecture to facilitate extension. We apply ontology to GMDEF Schema to share and reuse vocabularies of specific mechanical elements.

• Journal of the Korea Safety Management & Science
• /
• v.3 no.1
• /
• pp.11-24
• /
• 2001

Since the types and formats of the provided material and data are difficulties from one to another, difficulties have occurred in exchanging and sharing Information. Under such a circumstance, standardization and management of information or files have been a critical factor leading to an active and successful Electronic Commerce. XML(extensible Markup Language), which is a standardized format for data exchange via internet, has been recognized as a standard by World Wide Web Consortium(W3C). XML takes web environment as the interface, runs well even in a heterogeneous environment and saves data in a standardized format, therefore, it can be effectively used for creating and transferring standardized files. In this paper, a XML-based data processing system, which aims at supplementing the existing HTML-based shopping mall system and the methodology for constructing the system is presented with specific examples.

• Journal of KIISE:Databases
• /
• v.34 no.1
• /
• pp.1-17
• /
• 2007

As XML is becoming a de facto standard for distribution and sharing of information, the need for an efficient yet secure access of XML data has become very important. To enforce the fine-level granularity requirement, authorization models for regulating access to XML documents use XPath which is a standard for specifying parts of XML data and a suitable language for both query processing. An access control environment for XML documents and some techniques to deal with authorization priorities and conflict resolution issues are proposed. Despite this, relatively little work has been done to enforce access controls particularly for XML databases in the case of query access. Developing an efficient mechanism for XML databases to control query-based access is therefore the central theme of this paper. This work is a proposal for an efficient yet secure XML access control system. The basic idea utilized is that a user query interaction with only necessary access control rules is modified to an alternative form which is guaranteed to have no access violations using tree-aware metadata of XML schemes and set operators supported by XPath 2.0. The scheme can be applied to any XML database management system and has several advantages over other suggested schemes. These include implementation easiness, small execution time overhead, fine-grained controls, and safe and correct query modification. The experimental results clearly demonstrate the efficiency of the approach.

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

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.15 no.4
• /
• pp.231-237
• /
• 2015

However XML languages can logically define the type of structure with their's own grammar, it is inadequate to use them as a tool for conceptual model that represents the semantics of data and the relationships between the data in the real world. In this paper, we propose conceptual modeling techniques, called CMXML, for modeling the XML schema at the conceptual level. For this purpose, we define the model formally, and provide a way to represent the model in a graphical and text form. We also propose an mapping methodology providing transformation from CMXML to XML schema to show the feasibility of the proposed model.