• Journal of KIISE:Databases
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• v.30 no.4
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• pp.420-428
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• 2003

XML is a data-oriented language to represent all types of documents including web documents. By means of the advent of XML-based document generation tools and grow of proprietary XML documents using those tools and translation from legacy data to XML documents at an accelerating pace, we have been gotten a large amount of differently-structured XML documents. Therefore, it is more and more important to retrieve the right documents from the document set. But, previous works on XML have mainly focused on the storage and retrieval methods for a large XML document or XML documents had a same DTD. And, researches that supported the structural difference did not efficiently process path queries on the document set. To resolve the problem, we suggested a new inverted index mechanism using RDBMS and proved it outperformed the previous works. And especially, as it showed the higher efficiency in indirect containment relationship, we argues that the index structure is fit for the differently-structured XML document set.

• The KIPS Transactions:PartB
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• v.15B no.4
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• pp.355-364
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• 2008

In general, we can use an inverted index for retrieving element lists from structured documents. An inverted index can retrieve a list of elements that have the same tag name. In this approach, however, the cost of query processing is linear to the length of a path query because all the structural relationships (parent-child and ancestor-descendant) should be resolved by structural join operations. In this paper, we propose an inverted index technique and a novel structural join technique for accelerating XML path query evaluation. Our inverted index can retrieve element lists for path segments in a parent-child relationship. Our structural join technique can handle lists of element pairs while the existing techniques handle lists of elements. We show through experiments that these two proposed techniques are integrated to accelerate evaluation of XML path queries.

• Journal of KIISE:Software and Applications
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• v.31 no.3
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• pp.343-352
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• 2004

Recently, the information processing of ever increasing bio-related data is becoming a very important issue. One of the main sources of these bio-data comes with the form of biopathways, which includes molecular transactions and processes that are part of biochemical systems. The information represented by biopathways includes various organic relations among its components. However, most of the current systems to represent biopathways have been initially developed without computer processing in mind, and hence suffer from inconsistencies and ambiguities. In this paper, we propose an improved notation, called UniPath, for clear and systematic representation of biopathways. The proposed system is designed to provide a unified representation of metabolic and regulatory pathways. We also designed and implemented a graphic editor for UniPath to draw biopathwavs map according to the proposed notation. The graphic editor is designed so that biopathway data can be easily transformed into XML format.

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.905-913
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• 2008

Many heterogeneous XML documents are being widely used with the increasing employment of XML, and the importance of data structure research for more efficient document management has been growing steadily. We propose a query processing technique which uses parent node information in a partitioned inverted index tree. The searching efficiency of these heterogeneous documents is greatly influenced by the number of query processing and the amount of target data sets in many ways. Therefore, considering these two factors is very important for designing a data structure. First, our technique stores parent node's information in an inverted index table. Then using this information, we can reduce the number of query processing by half. Also, the amount of target data sets can be lessoned by using partitioned inverted index table. Some XML documents collected from the Internet will be used to demonstrate the new method, and its high efficiency will be compared with some of the existing searching methods.

• Proceedings of the Korea Information Processing Society Conference
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• 2006.11a
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• pp.325-328
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• 2006

최근 DTD (Document Type Descriptor)를 포함하고 있지 않은 XML 문서의 사용이 증가하고 있다. 따라서 서로 다른 구조를 갖는 많은 양의 XML 문서를 관계형 DBMS에 저장하거나, 인덱스를 이용하여 매핑하는 등 보다 효율적으로 관리하기 위한 다양한 인덱싱 기법에 대한 연구가 진행되고 있다. 이러한 연구들 중 경로 비트맵 인덱싱 기법은 경로 구성 유사도를 기반으로 3차원 비트맵 클러스터를 생성하고, 클러스터 단위의 검색을 수행함으로서 빠른 검색 속도를 보여주었다. 그러나 이 기법은 비교하려는 두 경로 중 항상 짧은 경로가 기준 경로가 되는 한계점과, 같은 노드 구성을 가지는 두 경로에서도 노드의 위치에 따라 그 유사도가 크게 변하는 등의 여러 문제점을 가지고 있었다. 이러한 문제점을 해결하고, 정확한 클러스터링을 수행하기 위해서는 합리적인 경로 유사도 계산식이 필요하게 되었다. 본 논문에서는 기존 방법의 문제점을 해결하고, 보다 정확한 클러스터링을 수행할 수 있는 새로운 경로 유사도 계산식을 제안한다.

• Journal of KIISE:Databases
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• v.29 no.1
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• pp.79-88
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• 2002

Data on the Internet are usually represented and transfered as XML. the XML data is represented as a tree and therefore, object repositories are well-suited to store and query them due to their modeling power. XML queries are represented as regular path expressions and evaluated by traversing each object of the tree in object repositories. Several indexes are proposed to fast evaluate regular path expressions. However, in some cases they may not cover all possible paths because they require a great amount of disk space. In order to efficiently evaluate the queries in such cases, we propose an optimized traversing which combines the signature method and block traversing. The signature approach shrink the search space by using the signature information attached to each object, which hints the existence of a certain label in the sub-tree. The block traversing reduces disk I/O by early evaluating the reachable objects in a page. We conducted diverse experiments to show that the hybrid approach achieves a better performance than the other naive ones.

• The KIPS Transactions:PartD
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• v.9D no.3
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• pp.355-364
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• 2002

Recently, WWW(World Wide Web) has become a source of a large amount of information, and is now recognized not only as an information-sharing tool, but also as an information repository. Currently, the majority of documents on the web were created using HTML(Hypertext Markup Language). Although HTML is simple and easy to learn, its inherent lack of describing document structure makes it difficult to retrieve information effectively. One possible solution would be to convert such HTML documents into XML (extensible Markup Language) documents. This is a standard markup language for exchanging data on the web. It can describe a document structure freely by defining its own DTD (Document Type Definition). This makes it possible to integrate, store, and retrieve data on the web efficiently In this paper, we will propose a converter that automatically converts HTML documents with similar pattern into XML documents by analyzing the document structure and recognizing its path information.

• Journal of KIISE:Databases
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• v.32 no.3
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• pp.334-343
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• 2005

Complex queries such as path alld twig patterns have been the focus of much research on processing XML data. Structural join algorithms use a form of encoded structural information for elements in an XML document to facilitate join processing. Recently, structural join algorithms such as Twigstack and TSGeneric- have been developed to process such complex queries, and they have been shown that the processing costs of the algorithms are linearly proportional to the sum of input data. However, the algorithms have a shortcoming that their processing costs increase with the length of a queery. To overcome the shortcoming, we propose the segment join technique to augment the structural join with structural indexes such as the 1-Index. The SegmentTwig algorithm based on the segment join technique performs joins between a pair of segments, which is a series of query nodes, rather than joins between a pair of query nodes. Consequently, the query can be processed by reading only a query node per segment. Our experimental study shorts that segment join algorithms outperform the structural join methods consistently and considerably for various data sets.

• The KIPS Transactions:PartD
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• v.11D no.5
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• pp.1021-1030
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• 2004

When any data-centric XML documents are stored and managed in RDBMS, schema extracting from XML Schema is an imminent problem. Furthermore, when they are stored in partitioned way on created table, lots of null values will be produced and/or be increased cost for join, so we need a solution to solve these problems. This paper proposes a Schema Hybrid Inlining technique to generate relational schema of XML documents. The suggested technique creates a relational schema based on the XML Schema graph. Also, the technique expands the legacy Inlining method by manual and heuristic processing table generation method of cardinality and in-degree. Then, an ancestor node, terminal node, and creating a new table on the derived relation in this technique. DTD-dependent storage method uses partitioned storing and relation path element information reformed structured-searching method to reduce joining operation cost that is a weak point of it.

• Journal of KIISE
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• v.43 no.4
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• pp.489-496
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• 2016

XML can effectively express structured or semi-structured data as well as relational databases. XQuery is a query language for retrieving information for such an XML document. In this paper, an XQuery composer is designed and implemented, with an API provided for XQuery processors, and a proper processor is registered. This composer shows query results immediately processed by the processor. As this composer contains a parser for XQuery, it can compose XQuery effectively using a diverse dialog box designed for XQuery grammar. A dialog box is affiliated with a clause region, which is a region that algebra operates from the parsing tree. It can compose path expressions for an XML document easily as it shows an element tree from DTD graphically. Path expressions are composed automatically by marking elements in the structural hierarchy and by specifying the predicate of an element partially.