• Journal of KIISE:Computing Practices and Letters
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• v.5 no.5
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• pp.628-638
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• 1999

In this paper, we presents a method of retrieving 24 bpp RGB images based on color-spatial features. For each image, it is subdivided into regions by using similarity of color after converting RGB color space to CIE L*u*v* color space that is perceptually uniform. Our segmentation algorithm constrains the size of region because a small region is discardable and a large region is difficult to extract spatial feature. For each region, averaging color and center of region are extracted to construct color-spatial features. During the image retrieval process, the color and spatial features of query are compared with those of the database images using our similarity measure to determine the set of candidate images to be retrieved. We implement a content-based color image retrieval system using the proposed method. The system is able to retrieve images by user graphic or example image query. Experimental results show that Recall/Precision is 0.80/0.84.

• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.7-12
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• 2009

In this paper, we discuss the problem of continuous k.nearest neighbors (CKNN) monitoring over distributed streams wavelet synopses, which also considered sliding window structure under stream based kNN query. We developed traditional skylines techniques and propose a new method which called DR.skylines to process CKNN queries as a bandwidth.efficient approach. It tries to process CKNN queries on synopses for optimized sliding window time and space computation.

• Journal of the Korea Society of Computer and Information
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• v.9 no.1
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• pp.31-36
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• 2004

As internet technology has rapidly developed, there have been works for the strategic techniques of the geographic information system integration and component that meet the situation of the variable customer requirement in endless change of execute environment. So there needs a design techniques of spatial data common component that can support technology and Query Processing, and so on. In this thesis, design techniques is proposed to support user-friendly interface and query currently available every place to provide these local-based software development technology. This process was evaluated through an verification test with a widely used development methodology The proposed methods is applied for computation and can reduce software development life cycle.

• Journal of KIISE:Databases
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• v.31 no.3
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• pp.219-231
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• 2004

Recently, together with increasing use of multimedia data, many works on moving objects in video databases have been made. Moving objects change visual features and spatial positions with the lapse of time in video data. And they arc related to the other objects or events. In this paper, we propose a new modeling and various query types of moving objects for content based retrieval in video databases. The proposed modeling represents visual features, moving trajectories and semantic contents related to objects. Therefore, it allows to process various query types. And we propose various query operators for the retrieval types. To show the superiority of our modoling, we implement the retrieval systems and compare it with the existing methods in terms of the supporting query types. The proposed method supports various query types and improves the efficiency of the query processing over the existing methods.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.69-74
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• 2004

Selectivity estimation for spatial query is very important process in finding the most efficient execution plan. Many works have been performed to estimate accurately selectivity. Although they deal with some problems such as false-count, multi-count, they require a large amount of memory to retain accurate selectivity, so they can not get good results in little memory environments such as mobile-based small database. In order to solve this problem, we propose a new technique called MW histogram which is able to compress summary data and get reasonable results. It also has a flexible structure to react dynamic update. The experimental results showed that the MW histogram has lower relative error than MinSkew histogram and gets a good selectivity in little memory.

• Journal of the Korea Computer Industry Society
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• v.5 no.9
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• pp.1025-1030
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• 2004

In multimedia database systems, the k nearest neighbor query occurs frerluently and requires the processing cost higher than other spatial queries do. The numberof searched nodes and the computation time in an index can be minimized for optimizing the cost of processing the k nearest neighbor query. In this paper, we propose the search distance which can reduce the computation time of the optimal search distance.

• The KIPS Transactions:PartD
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• v.11D no.2
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• pp.281-292
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• 2004

Selectivity estimation for spatial query is very important process used in finding the most efficient execution plan. Many works have been performed to estimate accurate selectivity. Although they deal with some problems such as false-count, multi-count, they can not get such effects in little memory space. Therefore, we propose a new technique called MW Histogram which is able to compress summary data and get reasonable results and has a flexible structure to react dynamic update. Our method is based on two techniques : (a) MinSkew partitioning algorithm which deal with skewed spatial datasets efficiently (b) Wavelet transformation which compression effect is proven. The experimental results showed that the MW Histogram which the buckets and wavelet coefficients ratio is 0.3 is lower relative error than MinSkew Histogram about 5%-20% queries, demonstrates that MW histogram gets a good selectivity in little memory.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.237-242
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• 2018

Recently, media data is increasing due to the development of Internet and SNS. Since photographs and videos often have geo-tags, many techniques have been developed to analyze them. In order to process various kind of such as SNS, NoSQL has been covered. However, most NoSQL does not have enough computation and query about spatial data. Therefore, in this paper, we designed and implemented a system for adding spatial operators using MongoDB among the representative NoSQL. Through this study, it is confirmed that various operators can be used and it is expected that various services can be performed using operators.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.11a
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• pp.512-519
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• 2002

In this paper, we implemented a loom component to be placed in a window and a looms management system which is able to connect database and to process various queries. The implemented system has aggregate query processing functions for the loom components existing in the selected area by the mouse and it also has high level query processing functions represented with chart and pivot table; it can be used as a decision support system. The proposed system can detect temporal or persistent problems of the Inn. Therefore, it can be used to raise the productivity and to reduce the cost in textile companies by coping with the situation properly.

• Journal of Korea Spatial Information System Society
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• v.6 no.1 s.11
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• pp.31-50
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• 2004

With the growth of wireless communication networks and mobile devices taking in GPS, Location-Based Service(LBS) is becoming an integral part of mobile applications. LBS can deal with location-aware features such as persons holding mobile phones or vehicles equipped with GPS, and provide the users with the location information of the features. Thus it is necessary to develop moving object database systems to store, manage, and query moving objects which change their locations continuously as time passes. In this paper, we design and implement a query processing component which deals with moving objects as a key data type. For this component, we define a new SQL-like query language(called MOQL) and as a consequence, design and implement modules that analyze and execute queries. It supports various types of operators that process range queries, infer topological relations, compute trajectories, and find k-nearest neighbors. It can be used as a subsystem if other application systems which deal moving objects and also supports ADO.NET interface that can be used to interact end-users.