• The KIPS Transactions:PartD
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• v.11D no.5
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• pp.1003-1010
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• 2004

In this paper, we address efficient processing of subsequence matching in time-series databases. We first point out the performance problems occurring in the index searching of a prior method for subsequence matching. Then, we propose a new method that resolves these problems. Our method starts with viewing the index searching of subsequence matching from a new angle, thereby regarding it as a kind of a spatial-join called a window-join. For speeding up the window-join, our method builds an R＊-tree in main memory for f query sequence at starting of sub-sequence matching. Our method also includes a novel algorithm for joining effectively one R＊-tree in disk, which is for data sequences, and another R＊-tree in main memory, which is for a query sequence. This algorithm accesses each R＊-tree page built on data sequences exactly cure without incurring any index-level false alarms. Therefore, in terms of the number of disk accesses, the proposed algorithm proves to be optimal. Also, performance evaluation through extensive experiments shows the superiority of our method quantitatively.

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.2 s.16
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• pp.11-22
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• 2000

It needs to extract the accurate topological characteristics and hydrological parameters of watershed in order to manage water resource efficiently. But, these data are processed yet by manual wok and simple operation in hydrologic fields. In this paper, we presented algorithm that could extract topological characteristics and hydrological parameters over watershed using GSIS and it gives the saving of data processing tin and the confidency of data. We presented coupling method between GSIS and hydrologic model by using extracted parameters into the input parameter of HEC-HMS hydrologic model. The extraction procedure of topological characteristics and hydrological parameters is as below. First, watershed and stream are extracted by DEM and curve unmber is extracted throughout the overlay of landuse map and soil map. Also, we extracted surface parameters like the length of the longest flow path and the slope of the longest flow path by Grid computation into watershed and stream. And we gave the method that could extract hydrologic parameters like Muskingum K and sub-basin lag tin by executing computation into surface parameters and average Sn curve number being extracted.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.1
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• pp.55-62
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• 2014

Diverse improvement projects such as replacing street lamps with LED, street trees, etc are currently in progress in Korea to reduce greenhouse gas so as to cope with change in climate. However, the effect of climate change policy is not exactly analyzed, because exhaust quantity and absorption quantity of greenhouse gas of the target street lamp and street trees are not arranged as information. Thus, this study studied the method to systematically manage low carbon related information of urban facilities by using GIS. It was found that low carbon information of the urban facilities is necessary to exactly analyze effect of climate change policy and the method to calculate carbon exhaust quantity and absorption quantity of each facilities should be established to build exact low carbon information of urban facilities. Further, it was found that the visualization of information related to low carbon of street lamp and street trees by using GIS easily and visually grasps and systematically controls the effect of policy coping with change in climate than the existing numeral data of exhaust quantity and absorption quantity of greenhouse gas.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.43-49
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• 2008

The Real Time Location System (RTLS) is very important in the ubiquitous society for real time tracking of men, high price assets, and logistics products. In this work, we developed an active RF system for RTLS and tested its performance. The RTLS system developed in this work was constructed of three active readers and one active tag. The small size tag developed in this work operated with a coin type battery. To make the tag smaller, we used an internal PCB antenna and a chip antenna. We tested the performance of the tag. To reduce the manufacturing cost of our RF system, we used low price RF transceiver CC2510 chip-set. The CC2510 chip-set provided RSSI(Received Signal Strength Indicator) signal which could be used to determine the distances between an active tag and three active readers.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.6
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• pp.112-122
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• 2009

In this paper, we present a novel space-frequency adaptive image restoration approach using vaguelette-wavelet decomposition (VWD). The proposed algorithm classifies a degraded image into flat and edge regions by using spatial information of the wavelet coefficient. For reducing the noise we perform an adaptive wavelet shrinkage process. At edge region candidates, we adopt entropy approach for estimating the noise and remove it by using relative between sub-bands. After shrinking wavelet coefficients process, we restore the degraded image using the VWD. The proposed algorithm can reduce the noise without affecting the sharpness details. Based on the experimental results, the proposed algorithm efficiently proved to be able to restore the degraded image while preserving details.

• Journal of the Korean Institute of Landscape Architecture
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• v.24 no.2
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• pp.74-85
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• 1996

The objective of this study is to investigate the influence of viewing aspects based on formal aesthetics and psychophysica approaches of the MAISAN provincial park for landscape management. Two methods are applied in this study. First, according to the field study with map the quantitative analyses of the viewshed area, visual section and scenery types were achieved, herein the visual landscape characteristics is found. Second, based upon visual preference evaluation of the relationships between the viewing aspects and visual preference scores to landscape slides were measured by questionnaires. The main conclusions obtained by the research are as follows. Visual area of MAISAN has a quite wide viewshed though itself is surrounded. The preference for the visual terminal were change by its characteristics to the visual corridors, view points, viewing types and viewing distance. Especially, the regression analysis between visual preference and viewing distance indicated Y=-3.20X\sup 2\+18.64X+20.64. In this case, viewing distance 794m from O\sub p\ is more important point for visual experience. The viewing types B·C and famous view A obtained a high visual preference score. A visual terminus are viewed along an entire RouteA, so revealed by its evolving spatial containment as to exact the full potential of its changing perspectives. Also we conducted the degree of visual influence by the shade in visual area at MAISAN and clarified viewing vantage Route and point in LSH being necessary for landscape preservation.

• Land and Housing Review
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• v.11 no.3
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• pp.49-59
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• 2020

The Seoul's 2030 Youth-Housing is a policy to promote the development of private sector-built rental housing in a Station Influence Area (SIA). It is a representative policy to resolve a housing problem for the youth in Seoul. The Seoul Metropolitan Government has made continuous policy improvements to respond to earlier criticisms on the policy. In December 2018, the Seoul Metropolitan Government enlarged the possible spatial boundaries of the SIA that the private sector developer can carry out the housing development projects. This study attempts to assess the potential sites available in Seoul by considering the youth's demand. This study used the suitability modelling technique to evaluate the potential sites. In detail, we established three sub-models by reflecting rent, accessibility to living areas of the youth, and accessibility to living SOC for the youth's demand. According to the results, the Hanyang City Wall area, which was newly included by the recent policy revision, showed moderate scores to fit the housing projects, while some Gangbuk areas, which have high accessibility and relatively lower rents, showed the best scores appropriate for the projects. The age group of 20s preferred university districts, while the age group of 30s preferred to locate near Seoul's main office areas. We suggest that the Seoul metropolitan government develops better ways to guage and reflect the demand for differing youth groups and the demand by age groups.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.249-253
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• 2006

We propose a new beamforming algorithm, which is based on simplex downhill optimization method in the presence of pilot channels in cdma2000 reverse-link, for the rake structure antenna array in DS/CDMA communication system. Our approach uses the desired signal(pilot) covariance matrix and the interference covariance matrix. The beamforming weights are made according to maximum SINR criteria using simplex downhill optimization procedure. Our proposed scheme provides lower computational load, better convergence speed, better performance than existingadaptive beamforming algorithm. The simplex downhill method is well suited to finding the optimal or sub-optimal weight vector, since they require only the value of the deterministic function to be optimized. The rake beamformer performances are also evaluated under several set of practical parameter values with regard to spatial channel model. We also compare the performance between conventional rake receiver and the proposed one under same receiving power.

• Journal of Biomedical Engineering Research
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• v.25 no.6
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• pp.537-543
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• 2004

In order to create three-dimensional model for human body, a method that reconstructs geometric models from contour lines on cross-section images is commonly used. We can get a set of contour lines by acquiring CT or MR images and segmenting anatomical structures. Previously proposed method divides entire contour line into simply matched regions and clefts. Since long processing time is required for reconstructing cleft regions, its performance might be degraded when manipulating complex data such as cross-sections for human body. In this paper, we propose a fast reconstruction method. It generates a triangle strip with single tiling operation for simple region that does not contain branch structures. If there exist branches in contour lines, it partitions the contour line into several sub-contours by considering the number of vertices and their spatial distribution. We implemented an automatic surface reconstruction system by using our method which reconstructs three-dimensional models for anatomical structures.

• Journal of KIISE
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• v.43 no.1
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• pp.54-60
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• 2016

Brain gene expression information is closely related to the structural and functional characteristics of the brain. Thus, extensive research has been carried out on the relationship between gene expression patterns and the brain's structural organization. In this study, Principal Component Analysis was used to extract features of gene expression patterns, and genes were automatically classified by spatial distribution. Voxels were then clustered with classified specific region expressed genes. Finally, we visualized the clustering results for mouse hippocampal region gene expression with the Allen Brain Atlas. This experiment allowed us to classify the region-specific gene expression of the mouse hippocampal region and provided visualization of clustering results and a brain atlas in an integrated manner. This study has the potential to allow neuroscientists to search for experimental groups of genes more quickly and design an effective test according to the new form of data. It is also expected that it will enable the discovery of a more specific sub-region beyond the current known anatomical regions of the brain.