• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.1
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• pp.150-157
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• 2004

For the mobile GIS services, it is not acceptable to construct a new map database only for wireless service due to vast cost. But the existing map database cannot be used directly for the services due to narrow wireless bandwidth and shortage of mobile device resources. This thesis proposes spatial data simplification methods, thus, the existing map database enable the mobile GIS services. The proposing methods are based on the existing map generalization techniques. We extend it to mobile environments, and implement. This thesis also includes the issue of discriminative data simplification technique according to display level and map display interface suitable for mobile devices. Research results an estimated by experiments.

• The Transactions of the Korea Information Processing Society
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• v.7 no.1
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• pp.1-11
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• 2000

Up to the present, many GIS logical data models have been proposed to incorporate time dimension into traditional 2-dimensional (2D space) GIS databases. However, these models are difficult to implementation of multi-dimensional GIS and have problems of significant data redundancy and search performance. This paper proposes a new storage strategy and a separate storage structure, that is composed of current database and past database, in order to reduce data redundancy and improve search performance of temporal query. Also we design moving algorithm for migration from current database to past database, and design efficient search algorithm for temporal query.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.5
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• pp.1284-1288
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• 2008

Recently, there is increasing the development requirement of middleware and interface for GPS(Global Positioning System), RFID(Radio Frequency IDentification), sensor networks. GPS supports a useful location based service. RFID supports products logistic and distribution services through the identification. A sensor network collects a context information, such as humidity, temperature and atmospheric pressure. This paper implements and verifies a integrated service middleware for supporting efficiently process of sensing data collected from RFID, GPS and sensor network. This middleware have the temporary store function, the redundancy exclusion function, certification function, the classification function and the database storage function. Additionary, this middleware connects with low-level adaptor using socket interface and supports the high-level application services using database connection. Therefore, user can develop easily various many ubiquitous application system using proposed middleware instead of each RFID middleware, GPS middleware and, middleware based on sensor network.

• The KIPS Transactions:PartD
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• v.14D no.6
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• pp.615-622
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• 2007

Recently, users who want to be provided motile devices, such as PDP, PMP, and IPTV connected wireless internet, with multimedia contents are increasing due to an influence of multimedia contents. In the paper, we propose an efficient database design method for managing mobile multimedia services on home network systems. For this, we build relations using attributes required while providing multimedia services, and then design a database. Specially, we propose a database design method based on normalization theory to eliminate redundancies and update anomalies caused by a non trivial multi valued dependency in relations. In the experiments, we compare and analyze occurrence frequencies of data redundancies and update anomalies through query executions on the relation decomposed into normal forms. The results reveal that our database design is failrly effective.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.197-204
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• 2014

This paper investigates a design of optimization database structure layout of Message Oriented Analysis and Management Tool (MOMAT) for naval combat systems (NCS). The NCS is composed of heterogeneous and large-scale component such as communication service and data distribution servcies (DDS). Each components are massively made the data as components. To manage the messages, MOMAT is developed. Typical modeling tool have problems that low performance due to duplicate database tables. An efficient design that one of the database optimization is proposed to solve the problems in this paper. It reduces the number of tables and improves application response and processing time. Experiment results shows that an availability of proposed method in MOMAT and decrease of both amount of data from client node to server and sever load.

• Spatial Information Research
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• v.9 no.2
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• pp.353-368
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• 2001

Recently central and local governments developed a huge spatial database and system using full-scale Geographic Information System (GIS). But Inconsistent spatial data through duplicated database management drops off in efficiency and confidence of administration. It is difficult to share data because of their unique system and data type. Under these circumstances Ministry of Construction and Transportation (MOCT) has been carrying out Land Management Information System (LMIS) to computerize land administration and policy affairs and to implement land database such as law, spatial, attribute data. A prerequisite mission of LMIS is to develop open system for solving the problem of duplicated data management and data sharing and for supporting various computer environments such as hardware, software, network etc. The purpose of LMIS is to reuse the existing investment resources and to expand the existing system resources. Therefore the purpose of this study is to investigate a method of LMIS operation under the existing circumstances and expansion of the system in the future. To do this, Supporting various DBMS, GIS server, Distributing Computing Platform(Unix, NT Server) is needed. Especially LMIS need to be developed as open system with interoperability to get independence of application from various GIS servers.

• The KIPS Transactions:PartD
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• v.10D no.4
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• pp.591-602
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• 2003

Delay and discontinuance phenomenon of service are cause by sudden increase of the network communication amount and the quantity consumed of resources when Internet users are driven excessively to a conventional single large database sewer. To solve these problems, spatial database cluster consisted of several single nodes on high-speed network to offer high-performance is risen. But, research about spatial join operation that can reduce the performance of whole system in case process at single node is not achieved. So, in this paper, we propose efficient parallel spatial join processing method in a spatial database cluster system that uses data partitions and replications method that considers the characteristics of space data. Since proposed method does not need the creation step and the assignment step of tasks, and does not occur additional message transmission between cluster nodes that appear in existent parallel spatial join method, it shows performance improvement of 23% than the conventional parallel R-tree spatial join for a shared-nothing architecture about expensive spatial join queries. Also, It can minimize the response time to user because it removes redundant refinement operation at each cluster node.

• Journal of the Korean Society for Library and Information Science
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• v.38 no.3
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• pp.119-139
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• 2004

This study intends to evaluate the quality of the Digital Library System DB and to suggest methods for its quality control. The evaluation criteria are hit rates, redundancy, completeness and accuracy. In spite of high hit rates excessive records representing one work resulted serious redundancy. The average completeness rate of records was $48.12\%$ due to low level of description. The Analysis of accuracy showed various errors in most of records corresponding to $92\%$. Emphasis on analysing the errors in detail detected the causing factors and suggested practical guidelines for school libraries' catalogers.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.861-864
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• 2007

Companies have developed local database without purpose of cooperation with others in the same category. That's because the cooperative work would cause cost in standardization, management, and usage of overlapping data. Therefore this paper proposes a system supporting an dynamic user interface for the sake of convenience of meta-data transformation and its users. The cooperative system will be able to connect companies together and minimize overlapping data by standardizing them. Eventually, the system will have an effect on cost-cutting and improve efficiency of maintenance and management.

• Journal of the Korea Computer Industry Society
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• v.3 no.7
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• pp.881-890
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• 2002

In this paper, by using agent technology, we proposes and implements the search system that supplies the result close to the user preference through the analysis of user preference. To offer better qualified information to user without redundant search results and unnecessary information of legacy search system. this system uses user's information and generates keywords and categories. Comparing user's favorite category with search result of legacy search system through the agent oriented search engine, it supplies only the result close to the user's category. At the same time, search result is saved into the databases according to each category to be used for search work later. As a result, the redundant information of search result was efficiently removed and the information close to the user's favorite category was obtained.