• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.210-213
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• 1988

By using Lyapunov method, sufficient conditions for linear time-varying continuous-time and discrete-time systems to be stable are presented under the assumption that the systems are slowly time-varying. Though it is not simple to find the stability regions immediately, one could find practical and large stability regions by constructing an appropriate algorithm.

• Journal of Forest and Environmental Science
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• v.28 no.4
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• pp.278-281
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• 2012

Comparative sequence analyses were conducted on complete mtDNA sequences from four small mammal species in Korea and revealed the presence of 30 well conserved sequences in various regions of the complete mtDNA sequences. The conserved sequences were found in 9 regions in protein coding genes, 10 regions in tRNA genes, 10 in rRNA genes, one region in replication origin and 2 regions in D loop. They could be used to design primers for amplifying complete mtDNA sequences of small mammals.

• Journal of Korea Multimedia Society
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• v.4 no.1
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• pp.67-74
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• 2001

In this paper, we propose a face detection algorithm using the color and shape information in color still images. The proposed algorithm is only applied to chrominance components(Cb and Cr) in order to reduce the variations of lighting condition in YCbCr color space. Input image is segmented by pixels with skin-tone color and then the segmented mage follows the morphological filtering an geometric correction to eliminate noise and simplify the segmented regions in facial candidate regions. Multiple facial regions in input images can be isolated by connected component labeling. Moreover tilting facial regions can be detected by extraction of second moment-based ellipse features.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.571-574
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• 2005

In this paper, we propose an efficient image segmentation technique for large-sized monochrome images using a hybrid approach which combines threshold and region-based techniques. First, an image is partitioned into fixed-size blocks and for each block the representative intensity is determined by averaging pixel intensities within the block. Next, the neighborhood blocks that have similar characteristics with respect to a specific threshold are merged in order to form candidate regions. Finally, those candidate regions are refined to get final target object regions by merging regions considering the spatial locality and certain criteria. We have performed experiments on images selected from various domains and showed that our technique was able to extract target object regions appropriately from most images.

• Journal of Sericultural and Entomological Science
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• v.43 no.1
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• pp.1-8
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• 2001

Nucleotide sequence in internal transcribed spacer (ITS) regions of ribosomal DNA among mulberry varieties (Morus species) were analyzed in order to identify the possibility of classification for the species. The variations in the ITS regions were compared among 9 mulberry varieties and one variety of Cudrania species as an outgroup. ITS 1 region of the varieties ranging from 219 to 220 bp in length was 49-50 bp shorter than ITS 2 region. Of 510 sites in the ITS 1 and 2 regions, 148 sites were potentially variable, of which 52% and 48% sites were distributed in ITS 1 and ITS 2 regions, respectively. By pairwise comparisons on the nucleotide sequences in the ITS 1 and 2 regions among 9 mulberry varieties, they were classified into 5 groups. Divergence values of the sequences, however, were considerably low ranging from 0 to 1.3%. Especially, there was no divergence among Backasipmunja, Chungilppong and Milsungpong and Jungyasang, Ssarigol II and Yulbon, respectively.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.79.1-79.1
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• 2014

We present the result of near-infrared (near-IR) imaging polarimetry of star-forming regions in the Large Magellanic Cloud (LMC). We compiled near-IR photometric and polarimetric data of N159/160 regions. The photometric and polarimetric data were simultaneously obtained in J, H, and Ks bands using SIRPOL, an imaging polarimeter of the InfraRed Survey Facility (IRSF), in 2007 February. We measured Stokes parameters of point-like sources to derive their degree of polarization and polarization position angles. In this poster, we present polarization properties of these star-forming regions. We also discuss the polarization structure in these regions compared with mid-infrared dust emission structure from the Spitzer SAGE survey.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.60.2-60.2
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• 2014

Hierarchical structure of star-forming regions is widespread and may be characteristic of all star formation. We studied the hierarchical structure of star-forming regions in the Local Group galaxies (M31, M33, Phoenix, Pegasus, Sextans A, Sextans B, WLM). The star-forming regions were selected from Galaxy Evolution Explorer (GALEX) far-UV imaging in various detection thresholds for investigating hierarchical structure. We examined the spatial distribution of the hot massive stars within star-forming regions from Hubble Space Telescope (HST) multi-band photometry. Small compact groups arranged within large complexes. The cumulative mass distribution follows a power law. The results allow us to understand the hierarchical structure of star formation and recent evolution of the Local Group galaxies.

• ETRI Journal
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• v.34 no.4
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• pp.564-571
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• 2012

This paper presents an algorithm for removing high-density impulsive noise that generates some serious distortions in edge regions of an image. Although many works have been presented to reduce edge distortions, these existing methods cannot sufficiently restore distorted edges in images with large amounts of impulsive noise. To solve this problem, this paper proposes a method using connected lines extracted from a binarized image, which segments an image into uniform and edge regions. For uniform regions, the existing simple adaptive median filter is applied to remove impulsive noise, and, for edge regions, a prediction filter and a line-weighted median filter using the connected lines are proposed. Simulation results show that the proposed method provides much better performance in restoring distorted edges than existing methods provide. When noise content is more than 20 percent, existing algorithms result in severe edge distortions, while the proposed algorithm can reconstruct edge regions similar to those of the original image.

• Journal of The Korean Astronomical Society
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• v.38 no.1
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• pp.7-12
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• 2005

The frequency distribution of HII regions radii in our galaxy has been investigated. The correlation between the number of these regions and their radii has been re-determined, and could be represented by an exponential function. The size distribution of the HII regions in 10 spiral galaxies has been derived and combined with that of our galaxy to derive the distances of these galaxies. It has been found that the distances derived are in a good agreement with the published ones. The interstellar extinction in the galaxies has no influence on the distance estimate when using this geometrical method.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.2
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• pp.111-120
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• 1991

A study was conducted to determine the macromineral status of grazing cattle in three climatic regions of the province of South Sulawesi, Indonesia. Soil, forage, blood and rib bone samples were collected within the Western, Central and Eastern regions, respectively, in February-March and August-September of 1987. Calcium and magnesium were not deficient in soil samples. For forages, calcium and phosphorus were deficient for all regions and forage sodium was deficient except for the western region in the dry season. Crude protein was deficient during the dry season. The overall percentage of deficient plasma phosphorus samples was 17 or 23% for the wet and dry seasons, respectively. Based on these analyses, macrominerals most likely deficient in both seasons were phosphorus and calcium in all regions, in addition to sodium in the Central and Eastern regions.