• Journal of KIISE:Computing Practices and Letters
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• v.9 no.2
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• pp.109-122
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• 2003

As XML documents become popular in the World Wide Web, a lot of research is being done on XML storage systems that store and manage XML documents using existing DBMSS. However, most of them have been done in the context of relational DBMSS rather than object-relational DBMSS, which have more powerful modeling capability than relational ones. In this paper, we design and implement an XML storage system, ODYSSEUS/XMLStore, for the ODYSSEUS object-relational DBMS that has been under development at KAIST. First, we analyze the mapping from the structure of XML documents to the relational or object-relational database schema. Second, we propose a method for describing the mapping analyzed using a standard language, XML Schema. Third, we propose a storage structure for storing the mapping information specified by the users in the database. Fourth, we propose detailed algorithms for storing XML documents in the relational or object-relational database based on the mapping information provided by the users.

• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.113-116
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• 2001

XML (extensible Markup Language) is a flexible way to create common information formats and share both the format and the data on the World Wide Web, intranets, and elsewhere. A document type definition (DTD) is a specific definition of the rules of the Standard Generalized Markup Language. A relational database management system (RDBMS) is a program that lets you create, update, and administer a relational database. An RDBMS takes Structured Query Language (SQL) statements entered by a user or contained in an application program and creates, updates, or provides access to the database. This paper has been studied a method of mappings from XML DTD to RDB schemas based on object model.

• IE interfaces
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• v.17 no.3
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• pp.330-337
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• 2004

Since XML (eXtensible Markup Language) was highlighted as an information interchange format, there is an increasing demand for incorporating XML with databases. Most of the approaches are focused on RDB (Relational Databases) because of legacy systems. But these approaches depend on the database system. Countless researches are being focused on DTD (Document Type Definition). However XML Schema is more comprehensive and efficient in many perspectives. We propose a meta-model for XML Schema that is independent of the database. There are three processes to build our meta-model: DOM (Document Object Model) tree analysis, object modeling and storing object into a fixed DB schema using model mapping approach. We propose four mapping rules for object modeling, which conform to the ODMG (Object Data Management Group) 3.0 standard. We expect that the model will be especially useful in building XML-based e-business applications.

• Journal of KIISE:Databases
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• v.31 no.4
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• pp.432-443
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• 2004

As the XML data has been widely used in the Internet, it is necessary to store and retrieve the XML data by using DBMSs. However, relational DBMSs suffer from the model difference between graph structure of the XML data and table forms in relational databases. We propose an ORDBMS-based DTD-dependent XML data management system Xing. Xing stores XML data in a DTD-dependent form in an object database. Since the object database schema has a graph structure and supports multi-valued attributes, mapping from an XML data model and queries into an object data model and OQLs is a simple problem. For rapid storing of large quantities of the XML data, we use SAX parser with customized Xing-tree which requires a small memory space compared with the DOM-tree. Xing also returns the query result in an XML document form. We have implemented the Xing system on top of UniSQL object-relational DBMS for the validity checking and performance comparison. For XML genome data from GenBank, and experimental evaluation shows that Xing can provide significant performance improvement (maximum 10 times) compared with the relational approach.

• 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.

• The KIPS Transactions:PartD
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• v.9D no.2
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• pp.195-202
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• 2002

Information exchange on XML such as B2B electronic commerce is spreading. Therefore the systematic and stable management mechanism for storing the exchanged information is needed. For this goal there are many research activities for connection between XML application and relational database. But because XML data have hierarchical structures and relational database can store only flat-structured data, we need to store XML data in object-oriented database that support hierarchical structure. Accordingly the modeling methodology for storing XML data in object-oriented database is needed. In this parer, the transforming methods based on object model from XML DTD to object-oriented database schema is proposed. For this, we first introduce mapping methods that map XML DTD to object model and then we propose soem methods that transform from the object model to object-oriented database schema.

• 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 Internet Computing and Services
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• v.2 no.5
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• pp.81-91
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• 2001

XML is a standard markup language for exchange and storage of formed or well-formed information in World Wide Web, Because the source data of XML message for exchange of information in World Woo Web Is stored in legacy database systems. it is necessary the easier connection between XML application and database systems, In Oracle8i. 9i. informix and SQL2000. DBMS vendors extend their DBMSs for XML. This approach for the connection between XML application and database system is Platform-dependent and DBMS-dependent. Therefore it is necessary the platform- and DBMS-independent approach for the connection between XML application and database system, In this paper. we modeled a set of middleware components for relational database design based on XML DTD is modeled, Those components are modeled on object-based algorithm for connection between XML application and database system.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.5
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• pp.37-52
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• 2006

XML architecture is important to wireless or wired presentation. It is also important for data exchange between businesses. XML forces the separation of content from style and gives wired or wireless devices flexibility for interpretation. Separation of content, style, and logic is key to advanced architecture. XML can be exchanged among databases on multiple systems with presentation on wired or wireless devices. An XML schema might need to be defined, or an established DTD might need to be transformed to access a relational database on the server. The purpose of this study is to generate XML documents such as DTD, XML schema, RDB mapping using Tagfree's XML developer tools in order to experience whole processes mentioned above. Overall understanding of data structures of and database processing with XML documents, which is essential to XML programming and database processing, can be accomplished with this study without much endeavor to learn complex XML syntax. The future study can be extended on the subject of web programming with DOM or SAX API.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.305-316
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• 2004

XML is becoming the de facto standard for data exchange over the Internet as a semistructured data which properties are irregular and incomplete. Therefore, to handle these data efficiently. what we use storage devices and storage techniques are Primary factors. In this paper, we developed storage techniques, which take the virtues of an object-relational database and support various query types needed for XML query languages without regard to the DTD. The techniques are capable with connecting naturally with conventional data and reducing overheads caused by the characteristics of an XML data model.