• Journal of KIISE:Software and Applications
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• v.29 no.7
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• pp.436-449
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• 2002

This paper describes on our experience of developing the Database Connector as an interconnection method between multimedia database, and the streaming framework. It is possible to support diverse and mature multimedia database services such as retrieval and join operation during the streaming if an interconnection method is provided in between streaming system and multimedia databases. The currently available interconnection schemes, however have mainly used the file systems or the relational databases that are Implemented with separated form of meta data, which deafs with information of multimedia contents, and streaming data which deals with multimedia data itself. Consequently, existing interconnection mechanisms could not come up with many virtues of multimedia database services during the streaming operation. In order to resolve these drawbacks, we propose a novel scheme for an interconnection between streaming framework and multimedia database, called the Inter-Process Communication (IPC) based Database connector, under the assumption that two systems are located in a same host. We define four transaction primitives; Read, Write, Find, Play, as well as define the interface for transactions that are implemented based on the plug-in, which in consequence can extend to other multimedia databases that will come for some later years. Our simulation study show that performance of the proposed IPC based interconnection scheme is not much far behind compared with that of file systems.

• The Transactions of the Korea Information Processing Society
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• v.1 no.2
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• pp.163-171
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• 1994

The paper describes a design and implementation of a user interface system between a temporal database management system (DBMS) and a graphical display system. This interfacing system consists of a temporal DBMS, a graphical display system, and an interface control system. The temporal DBMS supports time and the graphical display system draws a graphic using an icon. The interfacing system shows the graphical animation with time factors by using a graphical knowledgeable. We describe how to interface them as well as the structure of temporal DBMS and graphical display system.

• Journal of KIISE:Databases
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• v.31 no.5
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• pp.445-456
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• 2004

The database schema is assumed to be stable enough to remain valid even as the modeled environment changes. However, in practice. data models are not nearly as stable as commonly assumed by the database designers. Even though a rich set of schema change operations is provided in current database systems, the users suffer from the problem that schema change usually impacts existing application programs that have been written against the schema. In this paper, we are exploring the possible solutions to overcome this problem of impacts on the application programs. We believe that for continued support of the existing programs on the old schema, the old schema should continue to allow updates and queries, as before. Furthermore, its associated data has to be kept up-to-date. We call this the program independency property of schema change tools. For this property. we devise so-called program independency schema evolution (PISE) methodology. For each of the set of schema change operations in the relational schemas, the sketch of the additional algorithms due to the PISE compliance is presented in order to prove the comprehensiveness and soundness of our PISE methodology.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.728-736
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• 1994

본 연구는 MRP(Material Requirement System) 시스템의 기본 요소인 BOM(Bill of Material)의 효과성 분석을 목적으로 한다. BOM은 부품의 구성 관계를 나타내는 표로서, 근자에는 모듈화의 개념이 도입된 Modular BOM이 제시되고 있다. Modular BOM은 부품의 구성 관계를 모듈화 함으로써 이들을 보다 편리하게 관리하고, 기존에 사용되어 오던 구조형 BOM의 불편함, 단점 등을 보완한다. 본 연구는 기존의 구조형 BOM과 modular BOM을 데이타베이스 관리면에서 분석함으로서, 모듈화한 BOM이 데이타 관리면에서 지니는 효과성을 분석하였다. 데이타 관리의 효과성 분석은 BOM 데이타 관리면에서 지니는 효과성을 분석하였다. 데이타 관리의 효과성 분석은 BOM 데이타베이스의 제품구성을 관계형 데이타베이스의 레코드 (또는 tuple)로 표현 함으로서, 특정 부분품으로 구성된 완제품들을 나타내기 위해 필요한 레코드 수를 기초로 하여 수행되었다. 이상의 논리에 근거하여 본 연구는 다음과 같은 데이타 관리 관점에서 분석한다. 1. 제품구성 표시를 위한 BOM 데이타베이스의 구성 레코드 수의 비교, 2. 새로운 제품의 추가나 기 제품의 제품구성 변경에 따른 갱신의 용이성 본 연구에서는 분석의 편의를 위하여 BOM 구성이 레벨을 무시한 단순형태의 2단계 BOM을 분석 대상으로 한다. BOM데이타 베이스 관리의 효과성은 제시된 레코드 수에 기초하여 데이타베이스의 규모와 변경 용이성의 측정 모형을 수립하고, 이들 모형을 modular BOM과 구조형 BOM에 적용함으로서 수행 되었다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1994.11a
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• pp.223-232
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• 1994

객체지향 데이타베이스 시스템에서 무결성은 중요한 개념이다. 이 무결성이 객체의 내부 메소드로 정의되고 구현하면 응용에서의 무결성 의미 파악이 어렵고, 또한 객체의 기본적인 메소드와 함께 모형화되기 때문에 데이타베이스 설계 작업이 복잡해진다. 본 논문에서는 무결성을 매소드로 처리할 때의 문제점을 극복하기 위하여 동적 데이타베이스의 동적 규칙을 이용하여 무결성 제약조건을 정의하고 유지시키는 객체지향 데이타베이스에서 무결성과 임무 분리를 유지시키는 기립을 제안한다.

• Spatial Information Research
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• v.1 no.1
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• pp.17-28
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• 1993

In order to minimize vectorizing tasks, which require huge reso¬urces and time and to support the census mapping effectively, the geographic information databases structure has been studied. The steps of the new approach are as follows. : Step 1, Scanning the maps of the whole country and storing the image data in raster format. Step 2, Vectorizing the data of specific items for Census operation such as Enume¬ration District, and then linking to attribute data in the text format. Step 3, Designing the database with a Tile and Multi-layer structure to make a continuous map logically. Step 4, Implement Censlls Mapping System(CMS) for efficient mapping and retrieving. As a consequence of this study, the cost, manpower and time effectiveness was proved and it was confirmed to produce lIseful and high-qual ified maps for the Census. In the future, this system wi II be able to provide many organizations and individuals with the various data based on geographical statistical information.

• Spatial Information Research
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• v.20 no.1
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• pp.59-69
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• 2012

For the USN(Ubiquitous Sensor Network) environment which generally uses spatial sensor data as well as aspatial sensor data, a sensor database system to manage these sensor data is essential. In this reason, some sensor database systems such as TinyDB, Cougar are being developed by many researchers. However, since most of them do not support spatial data types and spatial operators to manage spatial sensor data, they have difficulty in processing spatial sensor data. Therefore, this paper developed a spatial sensor database system by extending TinyDB. Especially, the system supports spatial data types and spatial operators to TinyDB in order to manage spatial sensor data efficiently and provides the memory management function and the filtering function to reduce the system overload caused by sensor data streams. Lastly, we compared the processing time, accuracy, and memory usage of the spatial sensor database system with those of TinyDB and proved its superiority through the performance evaluation.

• Journal of KIISE:Databases
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• v.30 no.5
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• pp.464-475
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• 2003

few sample objects and compressed histogram information of image databases. The histogram information is used to estimate the selectivity of spherical range queries and a small number of sample objects is used to compensate the selectivity error due to the difference of the similarity measures between meta server and local image databases. An extensive experiment on a large number of image data demonstrates that our proposed method performs well in the distributed heterogeneous environment.

• The KIPS Transactions:PartD
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• v.11D no.4
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• pp.747-754
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• 2004

Database administrators should be aware of performance characteristics of database systems in order to manage database system effectively. The usages of system resources in database systems could be quite different under database workloads. The objective of this paper is to identify and analyze performance characteristics of database systems in different workloads, which could help database tuners tune database systems Under the TPC-C and TPC-W workloads, which represent typical workloads of online transaction processing and electronic commerce respectively, we investigated usage types of resource that are determined by fourteen performance indicator, and are behaved in response to changes of four tuning parameters (data buffer, private memory, I/O process, shared memory). Eight out of the fourteen performance indicators cleary show the performance differences under the workloads. Changes of data buffer parameter give a influences to database system. The tuning parameter that affects the system performance significantly is the database buffer size in the both workloads.

• Journal of KIISE:Databases
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• v.32 no.5
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• pp.473-486
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• 2005

The Hippocratic database model recently proposed by Agrawal et at. incorporates privacy protection capabilities into relational databases. The authors have subsequenty proposed the Hippocratic XML daかabase model[4], an extension of the Hippocratic database model for XML databases. In this paper, we propose a new concept that we cail the dynamic predicate(DP) for effective access control in the Hippocratic XML database model. A DP is a novel concept that represents a dynamically constructed rendition that tan be adapted for determining the accessibility of elements during query execution. DPs allow us to effectively integrate authorization checking into the query plan so that unauthorized elements are excluded in the process of query execution. 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 219 times over the top-down access control strategy and by up to 499 times over the bottom-up access control strategy. The major contribution of our, paper is enabling effective integration of access control mechanisms with the query plan using the DP under the Hippocratic XML database model.