• Journal of KIISE:Databases
• /
• v.33 no.5
• /
• pp.437-452
• /
• 2006

In this paper, we propose an extended XPath specification which includes a special matching character '%' used in the LIKE operation of SQL in order to solve the difficulty of writing some queries to filter element contents well, using the previous XPath specification. We also present a novel technique for filtering a collection of document-centric XMLs, called Pfilter, which is able to exploit the extended XPath specification. Owing to sharing the common prefix characters of the operands in value-based predicates, the Pfilter improves the performance in processing those. We show several performance studies, comparing Pfilter with Yfilter in respect to efficiency and scalability as using multi-query processing time (MQPT), and reporting the results with respect to inserting, deleting, and processing of value-based predicates. In conclusion, our approach provides a core algorithm for evaluating the contains() function of XPath queries in previous XML filtering researches, and a foundation for building XML-based distributed information systems.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.05a
• /
• pp.557-560
• /
• 2005

XML 문서의 논리적인 구조와 의미적 태그의 사용은 구조와 내용에 기반 한 검색을 가능하게 하는 반면, 동일한 정보라 하더라도 구조와 형식이 매우 다양하게 표현되므로 정보검색에 어려움을 초래한다. 효율적인 XML 정보검색을 위해, 본 논문은 온톨로지를 기반으로 검색에 적합한 문서만을 선별하는 문서여과 방법, 대상문서에 적합한 최소한의 질의생성을 위한 온톨로지 정합 방법 그리고 문서에 내재된 의미적 정보의 검색을 위한 정합된 온톨로지 기반의 질의확장 방법을 각각 제안하였다. 제안한 방법의 효과 및 효율은 예제 XML 및 DTD 문서를 대상으로 실험되었다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2001.10c
• /
• pp.250-252
• /
• 2001

현재 무선인터넷 문서는 유선인터넷 문서와 호환되지 않으며 다양한 종류의 무선 마크업 언어들로 구성되어 있어서, 무선 인터넷 문서를 새롭게 구축해야하는 문제점을 가진다. 본 논문에서는 이를 해결하기 위한 방안으로 유선 인터넷 문서를 여러 종류의 문선 인터넷 문서로 변환할 수 있는 변환 시스템을 설계한다. 이 시스템은 기존의 무선 마크업 언어의 기능을 모두 지원해주는 XML응용인 XWML을 설계하여 유무선 문서의 중간모듈로 이용한다. 유선 인터넷 문서는 필터링과 포멧팅 과정을 거쳐 XWML문서로 변환된 후 문서생성모듈에서 WML, HDML mHTML등의 무선 인터넷용 문서를 생성한다. 따라서 유선 인터넷 문서를 다양한 문선인터넷 문서로 변환할 수 있기 때문에, 무선 인터넷 환경에 맞는 컨텐츠를 일일이 작성하지 않아도 되는 장점을 가진다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2005.11a
• /
• pp.117-120
• /
• 2005

XML 은 환경에 독립적인 특징으로 인하여 다양한 환경에서 데이터 교환을 위한 표준으로서 자리잡아가고 있다. 특히 분산 환경에서 스트림 데이터들도 XML 을 이용하여 표현되고 있는데 이러한 데이터에 대해 기존의 질의 언어를 사용하여 질의하기 위해서는 사용자들은 XML 문서의 구조를 알아야 하고, 같은 질의의 내용일지라도 XML 문서의 DTD 가 다르게 되면 사용자는 상이한 DTD 에 대해서 모두 다른 질의문을 작성하여야 한다. 이러한 사용자들의 불편함을 없애기 위하여 사용자에게 XML 문서의 구조에 대해서 고려 하지 않아도 검색할 수 있는 CXQuery 의 개념을 도입하여 스트리밍 XML 데이터를 효과적으로 처리할 수 있는 질의 처리 시스템을 구현하였다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.6
• /
• pp.849-854
• /
• 2007

It is difficult that we collect only target documents from the Innumerable Web documents. One of solution to the problem is that we select target documents on the Web site which services many documents of target domain. In this paper, we will propose an intelligent crawling method collecting needed documents based on URL pattern script defined by XML. Proposed crawling method will efficiently apply to the sites which service structuralized information of a piece with database. In this paper, we collected 50 thousand Web documents using our crawling method.

• Journal of KIISE:Databases
• /
• v.32 no.2
• /
• pp.193-203
• /
• 2005

XML (extensible Markup Language) is recognized as a standard of data representation and transmission on Internet. XPath is a standard for specifying parts of XML documents anda suitable language for both query processing and access control of XML. In this paper, we use the XPath expression for representing user queries and access control for XML. And we propose an access control method for XML, where we control accesses to XML documents by filtering query XPath expressions through access control XPath expressions. In the proposed method, we directly search XACT (XML Access Control Tree) for a query XPath expression and extract the access-granted parts. The XACT is our proposedstructure, where the edges are structural summary of XML elements and the nodes contain access-control information. We show the query XPath expressions are successfully filtered through the XACT by our proposed method, and also show the performance improvement by comparing the proposed method with the previous work.

• The KIPS Transactions:PartD
• /
• v.13D no.5 s.108
• /
• pp.661-670
• /
• 2006

With the development of e-Commerce and the proliferation of easily accessible information, information filtering systems such as recommender and SDI systems have become popular to prune large information spaces so that users are directed toward those items that best meet their needs and preferences. Until now, many information filtering methods have been proposed to support filtering systems. XML is emerging as a new standard for information. Recently, filtering systems need new approaches in dealing with XML documents. So, in this paper our system suggests a method to create multiform user profiles with XML's ability to represent structure. This system consists of two parts; one is an administrator profile definition part that an administrator defines to analyze users purchase pattern before a transaction such as purchase happens directly. an other is a user profile creation part module which is applied by the defined profile. Administrator profiles are made from DTD information and it is supposed to point the specific part of a document conforming to the DTD. Proposed system builds user's profile more accurately to get adaptability for user's behavior of buying and provide useful product information without inefficient searching based on such user's profile.

• Proceedings of the Korean Information Science Society Conference
• /
• 2007.06a
• /
• pp.13-14
• /
• 2007

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

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.29 no.1B
• /
• pp.73-85
• /
• 2004

SIn this paper, we introduce our experience for designing and implementing new concept of a global XML-based Peer-to-Peer (P2P) engine to support various P2P applications, and interconnection among PC, Web and mobile computing environments. The proposed P2P engine can support to heterogeneous data exchanges and web interconnection by facilitating with the text-base XML while message exchange are necessary. It is also to provide multi-level security functions as well as to apply different types of security algorithms. The system consist of four modules; a message dispatcher to scheduling and filtering the message, a SecureNet to providing security services and data transmission, a Discovery Manager to constructing peer-to-peer networking, and a Repository Manager to processing data management including XML documents. As a feasibility test, we implement various P2P services such as chatting as a communication service, white-board as an authoring tool set during collaborative working, and a file system as a file sharing service. We also compared the proposed system to a Gnutella in order to measure performance of the systems.