• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.127-137
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• 2006

We propose two phase filtering scheme to develop an efficient mechanism for XML databases to control query-based access. An access control environment for XML documents and some techniques to deal with fine-grained 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-based access. The basic idea utilized is that a user query interaction with only necessary access control rules is modified to an alternative form through a query optimization technique, which is guaranteed to have no access violations using tree-aware metadata of XML schemas. The scheme can be applied to any XML database management system and has several advantages such as small execution time overhead, fine-grained controls, and safe and correct query modification. The experimental results clearly demonstrate the efficiency of the approach.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.347-350
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• 2002

본 논문은 DTD가 있는 이용한 XML 문서의 관계 데이터베이스 저장 및 검색방법을 제안한다. XML 구조와 관계 데이터베이스 스키마의 구조적 불일치로 인하여 XML 문서의 저장을 위해서는 별도의 처리과정이 필요하다. 기존의 Shared Inling 방법과 Hybrid Inling 방법의 장점을 살리고 릴레이션의 단편과 과도한 조인을 처리하기 위해 Association Inling 방법을 제안한다. 또한, XQuery를 이용한 질의를 지원하기 위해 Association Inling 방법에 의해 생성된 저장 스키마를 확장하고, XQuery로 표현된 질의를 SQL로 변환한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.55-58
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• 2001

XML 문서의 저장 및 관리 방법으로 관계형 데이터베이스가 많이 사용되고 있다. 그러나 XML과 관계 데이터베이스의 구조상의 불일치로 인해 데이터 손실, 질의처리의 효율성 저하 등과 같은 문제가 발생한다. element의 순환, 다중값을 갖는 attribute들의 처리 등을 위한 별도의 처리방법이 필요하다. 따라서, 본 논문은 효율적인 저장, 관리 및 질의 처리를 고려하여 DTD 기반의 XML 문서를 관계 데이터 베이스에 저장하는 방법을 제시한다.

• International Journal of Internet, Broadcasting and Communication
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• v.9 no.2
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• pp.11-19
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• 2017

The growing use of XML markup language has made amount of heterogeneous. XML documents are widely available in the Web. As the number of applications that utilize heterogeneous XML documents grow, the importance of XML document extraction increases greatly. In this paper, we propose a XML schema conversion technique that converts reusable XML schema from XML documents. We convert the schema graph and we use the reusability pattern list. The converted XML schema is evaluated in terms of cohesion, coupling, and reusability. The converted XML schema could be used to construct databases for various fields where XML is used as an intermediation of data exchange.

• Journal of the Korea Society of Computer and Information
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• v.6 no.1
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• pp.38-44
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• 2001

Nowadays, the study on XML as a standard method of exchange of information is active as Internet technology develops. This thesis designs and implements XML documents storage system using uniSQL/X in object-relational database. The system takes advantage of the merits of object-oriented databases, so that the structural information of XML documents can be effectively represented. The system uses split-storage method to allow frequent modifications of XML documents and suggests DTD-independent model so that it can store XML documents without DTD. And retrieval speed is improved by solving the issue of data duplication.

• Journal of Information Technology Services
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• v.8 no.2
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• pp.157-171
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• 2009

In mobile XML environments, the efficient synchronization technique is required to maintain the consistency of replicated XML data because the same data can be replicated between so many different XML documents. In this paper, we propose a message digest based synchronization technique to maintain the consistency of replicated data between client XML documents and a server XML database in mobile XML environments. The proposed an XML data synchronization technique(XSA) has the advantage of model generality aspect and storage space aspect by using the tuple-based message digest table to detect the data conflicts. The proposed technique can be applicable to the application requiring the consistency of replicated XML data without any restrictions in the heterogeneous(between hierarchical XML documents and relational XML databases) mobile environments.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.317-324
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• 2004

Containment queries for XML documents is one of the most important query types, and thus the efficient support for this type of query is crucial for XML databases. Recently, object-relational database management system (ORDBMS) vendors try to store and retrieve XML data in their products. In this paper, we propose an extensible index to support containment queries over the XML data stored as BLOB type in ORDBMSs. That is, we describe how to implement the index using the extensibility feature of an ORDBMS, and describe its usage.

• Journal of Internet Computing and Services
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• v.6 no.4
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• pp.59-73
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• 2005

Caching query results and reusing them in processing of subsequent queries is an important query optimization technique. Materialized view and view indexing are the representative examples of such a technique. The two schemes had received much attention for relational databases, and have been investigated for XML data since XML emerged as the standard for data exchange on the Web. In XML view indexing, XML view xv which is the result of an XML query is represented as an XML view index(XVI), a structure containing the identifiers of xv's underlying XML elements as well as the information on xv. Since XVI for xv stores just the identifiers of the XML elements not the elements themselves, when xv is requested, its XVI should be materialized against xv's underlying XML documents. In this paper, we address the problem of integrating an XML view index management system with an RDBMS based XML storage system. The proposed system was implemented in Java on Windows 2000 Server with each of two different commercial RDBMSs, and used in evaluating performance improvement through XML view indexing as well as its overheads. The experimental results revealed that XML view indexing was very effective with an RDBMS based XML storage system while its overhead was negligible.

• Journal of KIISE:Databases
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• v.32 no.5
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• pp.558-566
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• 2005

The XML is the new standard fir data representation and exchange on the Internet. In this paper, we describe a new approach for evaluating a path-oriented query against XML document. In our approach, we propose the Parallel Match Indexing Fabric to speed up evaluation of path-oriented query using path signature and design the parallel match algorithm to perform a match process between a path signature of input query and path signatures of elements stored in the database. To construct a structure of the parallel match indexing, we first make the binary tie for all path signatures on an XML document and then which trie is transformed to the Parallel Match Indexing Fabric. Also we use the Parallel Match Indexing Fabric and a parallel match algorithm for executing a search operation of a path-oriented query. In our proposed approach, Time complexity of the algorithm is proportional to the logarithm of the number of path signatures in the XML document.

• Journal of KIISE:Databases
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• v.34 no.2
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• pp.153-165
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• 2007

XML is widely used in various applications as the standard for representing and exchanging data on the Web. XML Schema is the standard schema for XML and an XML document generated based on the XML Schema is called 'Valid XML document'. The XML Schema validity should be guaranteed after the XML document is updated. In this paper, we design an efficient method that verifies XML Schema validity before update, and so eliminates unnecessary validations. Also, we propose validation algorithms for each update. In addition, we propose the mapping between XML data and XML Schema and a storage method for XML Schema in order to efficiently extract the schema information for the validation. Finally, we compare the performance of the validation according to the storage methods.