• Journal of KIISE:Databases
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• v.30 no.2
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• pp.134-144
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• 2003

Spatial relationships among objects are one of the important ingredients for expressing constraints of an image in image or multimedia retrieval systems. In this paper, we propose a unified image retrieval scheme using spatial relationships among objects and their features. The proposed scheme is especially effective in computing similarity between query image and images in the database. Also, objects and their spatial relationships are captured and annotated in XML. It could give better precision and flexibility in retrieving images from database. Finally, we have implemented a prototype system for retrieving images based on proposed technique and showed some of the experiment results.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.623-632
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• 2007

GML is a markup language presented as exchange standard for geographic information by the OGC(Open GIS Consortium). In spatial network databases, researches for supporting GML(Geographic Markup Language) can be divided into the parsing, the storing and the retrieval of GML documents. Among them, the study on the storage of GML documents is essential for their efficient retrieval. However there is little research on the storing of GML documents whereas there have been a lot of researches on the storing of n documents. Because the storage schema designed for XML documents are not appropriate for geographic information, we, in this paper, propose three storage schema for efficiently storing GML documents including geographic information in order to solve the problem that the XML storage schema store duplicate data and need to search many tables for obtaining elements. In addition, we design and implement a low-level storage manager which can store GML documents using the proposed GML storage schema.

• Journal of KIISE:Databases
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• v.32 no.3
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• pp.326-333
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• 2005

Many XML applications use XPath Patterns as a query language for XML documents. Two XPath patterns may have containment relationship, and the containment problem between two XPath patterns is a problem that determines whether one XPath pattern contains another XPath Pattern. Although the containment problem occurs in many applications, it is known as a co-NP complete. A homomorphism problem, which is a sufficient condition for the containment problem, is solved in polynomial time. We first discuss applications that replace the containment problem with the homomorphism problem, and maintaining homomorphism information among XPath patterns will benefit those applications. Then, we propose a lattice structure, called POX (Partially Ordered Set of XPath Patterns), and develop algorithms for maintaining it. As our analyses show, the algorithms can efficiently maintain POX in polynomial time.

• Journal of KIISE:Databases
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• v.35 no.1
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• pp.29-43
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• 2008

Although RDF ontologies might be expressed in XML tree model, existing methods for protection of XML documents are not suitable for securing RDF ontologies. The graph style and inference feature of RDF demands a new security model development. Driven by this goal, this paper proposes a new query-oriented model for the RDF ontology access control. The proposed model rewrites a user query using a three-layered ontology view. The proposal resolves the problem that the existing approaches should generate inference models depending on inference rules. Accessible ontology concepts and instances which a user can visit are defined as ontology views, and the inference view defined for controling an inference query enables a controlled inference capability for the user. This paper defines the three-layered view and describes algorithms for query rewriting according to the views. An implemented prototype with its system architecture is shown. Finally, the experiment and comparative evaluation result of the proposal and the previous approach is described.

• Journal of KIISE:Databases
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• v.33 no.1
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• pp.138-149
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• 2006

As the environment with sensor network and ubiquitous computing is emerged, there are many demands of handling continuous, fast data such as streaming data. As work about streaming data has begun, work about management of streaming data in Publish-Subscribe system is started. The recent emergence of XML as a standard for information exchange on Internet has led to more interest in Publish - Subscribe system. A filtering technique of streaming XML data in the existing Publish- Subscribe system is using some schemes based on automata and YFilter, which is one of filtering techniques, is very popular. YFilter exploits commonality among path queries by sharing the common prefixes of the paths so that they are processed at most one and that is using the top-down approach. However, because partial matching path queries interrupt the common prefix sharing and don't calculate from root, throughput of YFilter decreases. So we use sharing of commonality among path queries with the common postfixes of the paths and use the bottom-up approach instead of the top-down approach. This filtering technique is called as PoSFilter. And we verify this technique through comparing with YFilter about throughput.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.59-67
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• 2006

In this paper, we propose an effective use of SuperSQL for efficient media publication that utilizes relational databases. SuperSQL is an enhanced SQL processing system that converts data stored in relational databases into a variety or applied formats, such as XML and HTML, as a result or query. In order to integrate various media generators in SuperSQL query processor, we discuss methods to prepare both for new media promptly and for efficient media publication processing system. This research makes two main contributions: (1) it is a study about methods to integrate media generators by combining common processes in SuperSQL query processor, and (2) it introduces the trinity data model, which divide the media generating processes into three aspects, which are value, structure and medium abstraction. We also show the good performance and feasibility of our system.

• Journal of KIISE:Databases
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• v.31 no.3
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• pp.232-242
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• 2004

Metadata is a general notion of data about data to improve data sharing and exchanging by definitely describing meaning and representation of data. However, metadata has been created in various ways and It caused another kind of heterogeneity problem named metadata heterogeneity problem. Recently, the research on metadata gateway approach that allows metadata heterogeneity is being more actively progressed. However, the existing commercialized systems that have been implemented with the metadata gateway approach are dependent on a metadata schema. In this paper, we propose a message conversion system which separates the mapping information from the mapping rules between heterogeneous metadata schemas. The proposed system dynamically manages standardized data elements by applying ISO/IEC l1179. Therefore, the proposed system provides the set of standard data elements to create consistently metadata of new databases and provides a fundamental resolution to the metadata heterogeneity problem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.427-435
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• 2011

The information management system for the national R&D reports on the level of each government department have been operated in order to have special affiliated organizations collect detailed information, construct databases for R&D reports, and operate their information system; thus, the current classification system for the R&D reports on the governmental level is insufficient. Also, each department requires to prepare a standardized electronic original text service system since mutually different electronic original text services have been provided. therefore, this paper sets up the following research goals and detailed research contents. The goals of this study are to establish methods to standardize the forms of national R&D reports and suggest the framework for XML-based national R&D reports services by analyzing the problems in the forms of previous national R&D reports services. As detailed research contents, first, Identify the current R&D electronic original reports services by each government department. Second, this paper analyzed primary overseas science technology information service systems related with national research and development reports and related database schemata. this paper proposed the XML-based national R&D reports service framework through analyzing the problems in the framework of the existing national R&D reports service system and also established and suggested the methods to provide database schema design and report portal services. Lastly, it is expected that this paper will have academic contribution to enhancing R&D investment efficiency by utilizing collaboratively the information and resources related with national R&D through establishing the general information management system for national-dimension R&D reports and also managing science technology information efficiently and developing a user-centered integrated information system.

• Journal of KIISE:Databases
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• v.33 no.7
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• pp.715-726
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• 2006

Web service technologies provide a standard means for interoperation and integration of heterogeneous applications distributed over the Internet. For efficient execution of hierarchically interacting composite web services, this paper proposes an approach to distribute web service invocations over peer systems effectively, exploiting intensional XML data embedding external service calls as a result of well services. A cost-based optimization problem on the execution of web services using intensional results was formalized, and a heuristic search method to find an optimal solution and a greedy algorithm to generate an efficient invocation plan quickly were suggested in this paper. Experimental evaluation shows that the proposed greedy algorithm provides near-optimal solutions in an acceptable time even for a large number of Web services.

• Journal of Korea Spatial Information System Society
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• v.9 no.2
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• pp.35-53
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• 2007

GML is a mark-up language which is suggested by OGC(Open GIS Consortium) for use of encoding standard concerning with storing and transferring Geographic information. For general spatial network database, researches supporting GML documents can be classified into three categories : parsing, storing, and retrieval of GML documents. Among them, the 'Storing of GML document' is essential for efficient GML document retrieval. However, There is little research on schema for storing GML documents. In addition, the existing schema for storing XML documents can't be used for GML documents due to geographic information. Therefore, In this paper, we propose efficient schema for storing GML documents In addition, we do performance evaluation of the GML schema.