• Proceedings of the Korean Information Science Society Conference
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• 2000.04a
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• pp.36-38
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• 2000

An optoelectronic database filter chip for high performance database computers and applications is proposed. The proposed device is designed to perform the selection and projection operations of relational database operation on-the-fly in page-parallel manner to increase the overall performance of a database system. The device utilizes CMOS smart pixel array consists of detector and combinational logic circuit to perform the selection and projection operation.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.26 no.3
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• pp.1-9
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• 2003

Databases are central to business information systems and RDBMS is most widely used for the database system. Normalization was designed to control various anomalies (insert, update, delete anomalies). However, normalized database design does not account for the tradeoffs necessary for performance. In this research, I model a database design method considering denormalization of duplicating attributes in order to reduce frequent join processes. This model considers response time for processing each select, insert, update, delete transaction, and for treating anomalies. A branch and bound method is proposed for this model.

• Journal of Korea Multimedia Society
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• v.22 no.9
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• pp.1036-1045
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• 2019

Relational databases have a notion of normalization, in which the model for storing data is standardized according to the organization's business processes or data operations. However, the graph database is relatively early in this standardization and has a high degree of freedom in modeling. Therefore various models can be created with the same data, depending on the database designers. The essences of the graph database are two aspects. First, the graph database allows accessing relationships between the objects semantically. Second, it makes relationships between entities as important as individual data. Thus increasing the degree of freedom in modeling and providing the modeling developers with a more creative system. This paper introduces different graph models with test data. It compares the query performances by the results of response speeds to the query executions per graph model to find out how the efficiency of each model can be maximized.

• Journal of KIISE
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• v.42 no.9
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• pp.1147-1161
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• 2015

The ISO/IEC 11179 Metadata registry (MDR) is an international standard that was developed to register and share metadata. ISO/IEC 11179 represents an MDR as a metamodel that is an object model. However, it is difficult to develop an MDR based on ISO/IEC 11179 because the standard has no clear criteria to transform the metamodel into a database. In this paper, we suggest the design of an MDR data model that is based on object-relational transformation methodology (ORTM) for the MDR implementation. Hence, we classify the transformation methods of ORTM according to the corresponding relationships. After classification, we propose modeling rules by defining the standard use of the transformation. This paper builds the relational database tables as an implementation result of an MDR data model. Through experiments and evaluation, we verify the proposed modeling rules and evaluate the suitability of the created table structures. As the result, the proposed method shows that the table structures preserve classes and relationships of the standard metamodel well.

• Journal of KIISE:Databases
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• v.37 no.4
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• pp.197-202
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• 2010

Recent studies on change detection for RDF data are focused on not only the structural difference but also the semantic-aware difference by computing the closure of RDF models. However, since these techniques which take into account the semantics of RDF model require both RDF models to be memory resident, or they use a forward-chaining strategy which computes the entire closure in advance, it is not efficient to apply them directly to detect changes in large RDF data. In this paper, we propose a scalable change detection technique for RDF data, which uses a backward-chaining inference based on relational database. Proposed method uses a new approach for RDF reasoning that computes only the relevant part of the closure for change detection in a relational database. We show that our method clearly outperforms the previous works through experiment using the real RDF from the bioinformatics domain.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.684-698
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• 2004

The Hippocratic database model recently proposed by Agrawal et al. incorporates privacy protection capabilities into relational databases. Since the Hippocratic database is based on the relational database, it needs extensions to be adapted for XML databases. In this paper, we propose the Hippocratic XML database model, an extension of the Hippocratic database model for XML databases and present an efficient access control mechanism under this model. In contrast to relational data, XML data have tree-like hierarchies. Thus, in order to manage these hierarchies of XML data, we extend and formally define such concepts presented in the Hippocratic database model as privacy preferences, privacy policies, privacy authorizations, and usage purposes of data records. Next, we present a new mechanism, which we call the authorization index, that is used in the access control mechanism. This authorization index, which is Implemented using a multi-dimensional index, allows us to efficiently search authorizations implied by the authorization granted on the nearest ancestor using the nearest neighbor search technique. Using synthetic and real data, we have performed extensive experiments comparing query processing time with those of existing access control mechanisms. The results show that the proposed access control mechanism improves the wall clock time by up to 13.6 times over the top-down access control strategy and by up to 20.3 times over the bottom-up access control strategy The major contributions of our paper are 1) extending the Hippocratic database model into the Hippocratic XML database model and 2) proposing an efficient across control mechanism that uses the authorization index and nearest neighbor search technique under this model.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.323-329
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• 1998

Fatigue strength database system was developed for Windows 95 on personal computer. The relational database management system Visual Foxpro 5.0 was used. The database system developed contains 3,147 S-N curves and 311 $\varepsilon$-N ones for 437 material symbols and has the ability to search data by material symbol that each specification marks differently. Visual Basic 5.0 was used for graphic presentation and statistical treatment of the data searched.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.221.2-221.2
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• 2003

Several Compendia are effective in relation with production and supply of pharmaceutical agents in Korea. Those compendia exists only in printed documents, which are not suitable for the analysis of their contents and inter-relationship among them when they have specifications on the same or related pharmaceutical agents. For the analysis of contents of Korean compendia, database system is desinged and all of the available data are entered into relational database system. Every specification was analyzed into several database tables, fields and relations between tables. (omitted)

• Journal of KIISE:Computing Practices and Letters
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• v.6 no.2
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• pp.265-273
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• 2000

In relational database management systems(RDBMS), a table consIn relational database management systems(RDBMS), a table consists of sets of records which are composed of a set of attributes. The number of distinct values(NDV) of an attribute denotes the number of distinct attribute values that actually appear in the database records, and is widely used in optimizing queries and supporting statistic queries. Object-relational database management systems(ORBBMSS), however, support the inheritance between tables which enforces an attribute defined in a super-table to be inherited in sub-tables automatically. Hence, in ORDBMSS, not only NDV of an attribute In a single table but also NDV of an attribute in multiple tables(HNDV) is needed. In this paper, we propose a method that calculates HNDV using arrays of attribute value intervals. In this method, an array of attribute value intervals is created for an attribute of interest In each table in a table hierarchy, and HNDV can be calculated or estimated by merging the arrays of attribute value intervals. The proposed method accurately calculates HNDV using small additional storage space and is efficient for an environment where only some of the tables in a table hierarchy are frequently updated.

• Journal of Korean Society of Steel Construction
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• v.10 no.1 s.34
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• pp.37-45
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• 1998

The relational database system on fatigue strength was constructed, and the properties of fatigue life distribution were examined to analyze reliability and safety of metallic materials. Data manipulations were efficiently performed in relational fatigue strength database system using dependency diagram. Regardless of the distribution of fatigue strength, the proposed method, the Robust method and the complementary error function method using probability distribution, successfully estimated parameters of the 3-parameter Weibull distribution. The proposed criterion for estimating non-failure probability showed good results regardless of censoring time. The fatigue life distribution function described as a function of parameters of the Weibull distribution and applied stress ratio produced P-S-N characteristics reasonably.