• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.185-189
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• 2004

For face recognition system, a face detector which can find exact face region from complex image is needed. Many face detection algorithms have been developed under the assumption that background of the source image is quite simple . this means that face region occupy more than a quarter of the area of the source image or the background is one-colored. Color-based face detection is fast but can't be applicable to the images of which the background color is similar to face color. And the algorithm using neural network needs so many non-face data for training and doesn't guarantee general performance. In this paper, A multi-scale, multi-face detection algorithm using PCA is suggested. This algorithm can find most multi-scaled faces contained in static images with small number of training data in reasonable time.

• Journal of The Korean Astronomical Society
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• v.35 no.2
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• pp.67-73
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• 2002

We have made a topological study of cosmic microwave background (CMB) polarization maps by simulating the AMiBA experiment results. A ACDM CMB sky is adopted to make mock interferometric observations designed for the AMiBA experiment. CMB polarization fields are reconstructed from the AMiBA mock visibility data using the maximum entropy method. We have also considered effects of Galactic foregrounds on the CMB polarization fields. The genus statistic is calculated from the simulated Q and U polarization maps, where Q and U are Stokes parameters. Our study shows that the Galactic foreground emission, even at low Galactic latitude, is expected to have small effects on the CMB polarization field. Increasing survey area and integration time is essential to detect non-Gaussian signals of cosmological origin through genus measurement.

• Journal of Korea Society of Industrial Information Systems
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• v.13 no.4
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• pp.56-63
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• 2008

Image calibration at preprocessing step is very important for face recognition rate improvement, and background noise deletion affects accuracy of face recognition specially. In this paper, a method is proposed to remove background area utilizing elliptical model at preprocessing step for face recognition rate improvement. As human face has the shape of ellipse, a face contour can be easily detected by using the elliptical model in face images.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.347-350
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• 2011

This paper propose a statistical color model of background extraction base on Hue-Saturation-Value(HSV) color space, instead of the traditional RGB space, and shows that it provides a better use of the color information. HSV color space corresponds closely to the human perception of color and it has revealed more accuracy to distinguish shadows [3] [4]. The key feature of this segmentation method is based on processing hue component of color in HSV color space on image area. The HSV color model is used, its color components are efficiently analyzed and treated separately so that the proposed algorithm can adapt to different environmental illumination condition and shadows. Polar and linear statistical operations are used to calculate the background from the video frames. The experimental results show that the proposed background subtraction method can automatically segment video objects robustly and accurately in various illuminating and shadow environments.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.545-552
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• 2012

In this paper, we propose Modified Multi CAMShift Algorithm based on Kalman filter and Weighted Search Windows(KWMCAMShift) that extracts skin color area and tracks several human body parts for real-time human tracking system. We propose modified CAMShift algorithm that generates background model, extracts skin area of hands and head, and tracks the body parts. Kalman filter stabilizes tracking search window of skin area due to changing skin area in consecutive frames. Each occlusion areas is avoided by using weighted window of non-search areas and main-search area. And shadows are eliminated from background model and intensity of shadow. The proposed KWMCAMShift algorithm can estimate human pose in real-time and achieves 96.82% accuracy even in the case of occlusions.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.35-43
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• 2012

Purpose : PET/CT performed CT-based attenuation correction generates the beam hardening artifact by metallic implant. The attenuation correction causes over or underestimate of the area adjacent to metallic hip prosthetic material and change of $^{18}F$-FDG uptake. Also, the image quality and the diagnosability on genitourinary disease are reduced. Therefore, this study will evaluate the usefulness of MAR (Metal Artifact Reduction) algorithm method to improve the image quality on PET/CT. Materials and Methods : PET/CT was performed by fixing hip prosthesis in SPECT/PET phantom. In PET images with and Without MAR algorithm, the Bright streak, Dark streak, Metal region and Background area that appeared on CT were confirmed, and the change of each SUV (standardized uptake value) was analyzed. Also, in 15 patients who underwent total hip arthroplasty, each MAR algorithm and Without MAR algorithm and non attenuation correction was evaluated. Results : In PET image Without MAR algorithm, SUV of Bright streak region was $0.98{\pm}0.48$ g/ml; Dark streak region was $0.88{\pm}0.02$ g/ml; Metal region was $0.24{\pm}0.16$ g/ml, Background area was $0.91{\pm}0.18$ g/ml. In SUV of PET image with MAR algorithm, Bright streak region was $0.88{\pm}0.49$ g/ml, Dark streak region was $0.63{\pm}0.21$ g/ml, Metal region was $0.06{\pm}0.07$ g/ml, Background was $0.90{\pm}0.02$ g/ml. SUV generally decreased when applying MAR algorithm. In PET image Without MAR algorithm, SUVs of Bright region were higher than those measured in the Background, and it was false positive uptake. But, in PET image with MAR algorithm, SUVs of Bright region were similar to the Background, and false positive uptake disappeared. Conclusion : MAR algorithm could reduce an increase of $^{18}F$-FDG uptake due to attenuation correction in the hip surrounding tissue. However, decrease of SUV in Dark streak region should be considered in the future. Therefore, this study propose that the diagnostic accuracy can be improved in genitourinary diseases adjacent to metallic hip prosthesis, if provided PET images with and Without MAR algorithm, and non attenuation correction images at the same time.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.17-20
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• 2002

The environmental tracers of $^3$H and NO$_3$ were investigated in terms of vertical connections between basaltic aquifers and underlying sedimentary formations of Seoguipo formation that is not found in eastern coastal area and U formation. In western coastal area, $^3$H shows values less than 0.5TU In the wells completed in Seoguipo formation whereas it is greater than 2TU in other area. For the wells in western area, NO$_3$ concentrations are below background level though the nearby land uses are mainly agricultural. The groundwater heads are much lower in eastern coastal area than western area in spite that recharge rate of eastern area is 1.7 times higher than that of western area. The basaltic aquifer is thicker by 70m in eastern coastal area than in western coastal area, which is insufficient to explain much lower groundwater heads in eastern area. These hydrogeological characteristics suggest that for the basaltic aquifers, the Seoguipo formation acts as a lower boundary which could limit downward groundwater flow in basaltic aquifers whereas the U formation is unlikely.

• Korean Journal of Ichthyology
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• v.26 no.3
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• pp.185-193
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• 2014

To find the influence of water temperature, tank color and illumination in feeding, growth and blind-side hypermelanosis of starry flounder, Platichthys stellatus, in the present study, we performed a series of temperature, background color and illumination intensity test for 180 days (From June to December). The test was done in duplicate at 100 fish/tank (430% of initial covering area [PCA]) with the selected ordinary juvenile flounder (TL $17.3{\pm}0.5cm$, BW $82.5{\pm}0.2g$). The rearing was performed in darkgreen FRP aquarium tanks ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 1,000 lux and 230 lux, and in white FRP aquarium tank ($H100cm{\times}L100cm{\times}W100cm$; bottom area $1m^2$) lighten with average 230 lux of light intensity. We investigated correlation of daily food intake (DFI) with water temperature and salinity, and compared the influences of background colors and light intensity in DFI, food efficiency (FE), growth, survival rate, and ratio of malpigmented blind-side area and ambicolored fish ratio. In DFI, although it was not related with salinity, the amount was significantly decreased under 0.5 g/fish/day in summer and winter season, but was significantly increased over 1.5 g/fish/day in autumn season showing from $10^{\circ}C$ to $20^{\circ}C$ in water temperature. In background and illumination test, DFI, FE and survival rate showed no difference among three groups. The ratios of malpigmented blind-side area and ambicolored fish were also not significantly different among three groups, indicating that the blind-side hypermelanosis of starry may be governed not by background color (or light intensity) but by a genetics external trait inherited from parents.

• Journal of Korean Physical Therapy Science
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• v.16 no.3
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• pp.1-9
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• 2009

Background: The purpose of this study is to have examined the influence on the blood circulation by comparing the differences between stimulating the sympathetic ganglion and the muscle group among the stimulation variables in interferential current stimulation. Method: The object of the study is the twenties(M=8, F=12), who are in great condition and have no pathological report for the blood circulation influence. The intensity of the inferential current stimulation is the medium degree, 100 bps constant current, which is the comfort and degree to confirm the muscle contraction. The areas stimulated are the stellate ganglion area in the seventh cervical vertebrae and the forearm muscle area. Results: We have made sure that there is no change in blood pressure and pulse and that the change in the skin temperature occurred highly. Conclusion: In considering the change of the blood circulation in case of stimulation area by the inferential current stimulation, we have seen that stimulating the sympathetic ganglion area is more effective than stimulating muscle area directly.

• Journal of Distribution Science
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• v.10 no.12
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• pp.5-11
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• 2012

Purpose - This paper proposes measurement models to evaluate the management performance of small and medium-sized retail businesses on the basis of a trading area analysis that compares their proposed revenue to actual revenue in the trading area. Research design, data, methodology - The study proposes measurement models consisting of five stages, namely: (1) district background survey, (2) customer survey, (3) competitor survey, (4) business district survey, and (5) business performance analysis. Results - To identify business districts easily, this study preferred a minor-adjusted method based on the Euclidean distance, as it is simple to employ for the small and medium-sized businesses. This model was applied to select coffee shops in Daejeon. Results indicated that although the targeted shop was not located in an appropriate location, actual sales were higher than expected. Conclusions - Small- or medium-sized retail businesses face difficulties regarding the economies of scale and brand recognition and must choose an appropriate location to ensure management stability. However, such businesses will find it difficult to evaluate their competitive edge accurately using a trading area analysis.