• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.105-109
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• 2000

High-performance liquid chromatography is suitable for getting thermodynamic information about solute-solvent interactions. We used a squalane impregnated $C_{18}$ phase as a presumably bulk-like stationary phase to secure a simple partition mechanism for solute retention in reversed phase liquid chromatographic system. We measured retention data of some selected solutes (benzene, toluene, ethylbenzene, propylbenzene, butylbenzene, phenol, benzylalcohol, phenethylalcohol, benzylacetone, acetophenone, benzonitrile, benzylcyanide) at 25, 30, 35, 40, 45, and 50 $^{\circ}C$ in 30/70, 40/60, 50/50, 60/40 and 70/30 (v/v%) acetonitrile/water eluents. The van't Hoff plots were nicely linear, thus we calculated dependable thermodynamic values such as enthalpies and entropies of solute transfer from the mobile phase to the stationary phase based on more than four retention measurements on different days (or weeks). We found that the cavity formation effect was the major factor in solute distribution between the mobile and stationary phases in the system studied here. Our data were com-pared with some relevant literature data.

• Journal of Cadastre & Land InformatiX
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• v.45 no.1
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• pp.169-179
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• 2015

Recently, as the amount of data increases rapidly, the development of IT technology entered the 'Big Data' era, dealing with large-volume of data at once. In the spatial field, a spatial data service technology is required to use that various and big amount of data. In this study, firstly, we explained the technology of typical spatial information data services abroad, and then we have developed large KML data processing techniques those can be applied as KML format to VWorld desktop. The test was conducted using a large KML data in order to verify the development KML partitioned methods and tools. As a result, the index file and the divided files are produced and it was visible in VWorld desktop.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.2
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• pp.23-32
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• 2004

The query optimizer's important task while a query is invoked is to estimate the fraction of records in the databases that satisfy the given query condition. The query result size estimation in spatial databases, like relational databases, proceeds to partition the whole input into a small number of subsets called “buckets” and then estimate the fraction of the input in the buckets. The accuracy of estimation is determined by the difference between the real data counts and approximations in the buckets, and is dependent on how to partition the buckets. Existing techniques for spatial databases are equi-area and equi-count techniques, which are respectively analogous in relation databases to equi-height histogram that divides the input value range into buckets of equal size and equi-depth histogram that is equal to the number of records within each bucket. In this paper we propose a new partitioning technique that determines buckets according to the maximal difference of area which is defined as the product of data ranges End frequencies of input. In this new technique we consider both data values and frequencies of input data simultaneously, and thus achieve substantial improvements in accuracy over existing approaches. We present a detailed experimental study of the accuracy of query result size estimation comparing the proposed technique and the existing techniques using synthetic as well as real-life datasets. Experiments confirm that our proposed techniques offer better accuracy in query result size estimation than the existing techniques for space query size, bucket number, data number and data size.

• Spatial Information Research
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• v.18 no.4
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• pp.109-120
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• 2010

Recently, due to rapid increasement of spatial data collected from various geosensors in u-GIS environments, the importance of spatial index for efficient search of large spatial data is rising gradually. Especially, researches based R-Tree to improve search performance of spatial data have been actively performed. These previous researches focus on reducing overlaps between nodes or the height of the R -Tree. However, these can not solve an unnecessary node access problem efficiently occurred in tree traversal. In this paper, we propose a MR-Tree(Mapping-based R-Tree) to solve this problem and to support efficient search of large spatial data. The MR-Tree can improve search performance by using a mapping tree for direct access to leaf nodes of the R-Tree without tree traversal. The mapping tree is composed with MBRs and pointers of R-Tree leaf nodes associating each partition which is made by splitting data area repeatedly along dimensions. Especially, the MR-Tree can be adopted in various variations of the R-Tree easily without a modification of the R-Tree structure. In addition, because the mapping tree is constructed in main memory, search time can be greatly reduced. Finally, we proved superiority of MR-Tree performance through experiments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.1
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• pp.173-180
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• 2009

It is difficult to predict non-stationary or chaotic time series which includes the drift and/or the non-linearity as well as uncertainty. To solve it, we propose an effective prediction method which adopts data preprocessing and multiple model TS fuzzy predictors combined with model selection mechanism. In data preprocessing procedure, the candidates of the optimal difference interval are determined based on the correlation analysis, and corresponding difference data sets are generated in order to use them as predictor input instead of the original ones because the difference data can stabilize the statistical characteristics of those time series and better reveals their implicit properties. Then, TS fuzzy predictors are constructed for multiple model bank, where k-means clustering algorithm is used for fuzzy partition of input space, and the least squares method is applied to parameter identification of fuzzy rules. Among the predictors in the model bank, the one which best minimizes the performance index is selected, and it is used for prediction thereafter. Finally, the error compensation procedure based on correlation analysis is added to improve the prediction accuracy. Some computer simulations are performed to verify the effectiveness of the proposed method.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.5 no.1
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• pp.51-64
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• 1995

In distributed environments, the DB secure models have been being studied to include the multi-level mechanism which is effective to control access according to the level of the data value. These mechanisms have the problems. The first, it is impossible to maintain the global data which is protected in the multi-level mechanism. The second, the access and the relation of the data is not clear due to the access revocation between the local data and the global's. In this paper, we proposed the mechanism using shema. The mechanism doesn't have the access revocation, and provides the protection of the data and the control to the global data.

• Korean Journal of Remote Sensing
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• v.27 no.6
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• pp.717-728
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• 2011

An efficient method for the unsupervised classification of high resolution imagery is suggested in this paper. It employs pixel-linking and merging based on the adjacency graph. The proposed algorithm uses the neighbor lines of 8 directions to include information in spatial proximity. Two approaches are suggested to employ neighbor lines in the linking. One is to compute the dissimilarity measure for the pixel-linking using information from the best lines with the smallest non. The other is to select the best directions for the dissimilarity measure by comparing the non-homogeneity of each line in the same direction of two adjacent pixels. The resultant partition of pixel-linking is segmented and classified by the merging based on the regional and spectral adjacency graphs. This study performed extensive experiments using simulation data and a real high resolution data of IKONOS. The experimental results show that the new approach proposed in this study is quite effective to provide segments of high quality for object-based analysis and proper land-cover map for high resolution imagery of urban area.

• Korean Institute of Interior Design Journal
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• no.15
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• pp.62-68
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• 1998

Children develop in direct relation and response to their physical environment, The purposes of this study were to investigate the current interior design conditions of classrooms in kindergarten and to provide interior planning guidelines for children's behavioral and developmental improvement and better educational environment. Data were collected through interview and questionnaire survey. The sample included 239 teachers who were employed in 23 kindergartens located in Pusan. The data were analyzed by using SPSS-PC. The major findings were as follows; (1) Wood and wallpapers which provide various colors and patterns are recommendable as a classroom finish rather than paint which looks monotonous. (2) Teachers preferred 7 or 8 activity centers in classroom and furniture or partition is the best when dividing space. (3) Classroom should be large enough to locate various types of furniture that designed based on child-size and objects to store. (4) Activity centers should be lit by different types of task lighting such as floor lamp and backer to provide sufficient level of light.

• Journal of Korean Society for Quality Management
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• v.22 no.2
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• pp.143-153
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• 1994

Cluster analysis is a primitive technique in which no assumptions are made concerning the data structure. And the number of groups is known a priori discriminant analysis provides an information how well N individuals are classified into their own groups. In this study, clustering, which is any partition of a collection of data points, generated by the application of eight hierarchical clustering methods was re-classified by discriminant analysis. Then correct classification ratios were obtained for the application of discriminant analysis through each clustering method and the direct application of discriminant analysis. By comparing the correct classification ratios, the applicability of cluster analysis and discriminant analysis considered.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.279-284
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• 2000

The bridge is nation's principal structure and its influence for national economy is enormous. But it is essential for maintenance of deteriorated bridge because of the increased service life and the decreased performance. For the bridge reinforced by continuos slabs and post-tensioning, we evaluate th stress properties of girders and internal support. Results are almost coincidence between measured data in the field and analysed data by computer. We compared the effects by successive order of post- tensioning and order considered distribution of each girder's camber and stress. Bridge's camber and stress showed respectively symmetry and asymmetry shape by post tensioning order. For the effect of post-tensioning force partition, we divided the post-tensioning force into 3 types (100%, 20%, 30%), and the results show t도 difference of final stress and camber.