• The Transactions of the Korea Information Processing Society
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• v.7 no.2
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• pp.542-551
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• 2000

In this paper, a novel technique is presented for automatic brain region segmentation in single channel MR image data sets for 3D visualization and analysis. The method detects brain contours in 2D and 3D processing of four steps. The first and the second make a head mask and an initial brain mask by automatic thresholding using a curve fitting technique. The stage 3 reconstructs 3D volume of the initial brain mask by cubic interpolation and generates an intermediate brain mask using morphological operation and labeling of connected components. In the final step, the brain mask is refined by automatic thresholding using curve fitting. This algorithm is useful for fully automatic brain region segmentation of T1-weighted, T2-weighted, PD-weighted, SPGR MRI data sets without considering slice direction and covering a whole volume of a brain. In the experiments, the algorithm was applied to 20 sets of MR images and showed over 0.97 in comparison with manual drawing in similarity index.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.117-132
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• 2005

It was to study a following research of "A Kinematic Analysis of Air-rolling-breakfall in Judo". The purpose of this study was to analyze the Center of Gravity(COG) variables when performing Air-rolling-breakfall motion, while passing forward over(PFO) to the vertical-hurdles(2m height, take off board 1m height) in judo. Subjects were four males of Y. University squad, who were trainees of the demonstration exhibition team, representatives of national level judoists and were filmed by four 5-VHS 16mm video cameras(60field/sec.) through the three dimensional film analysis methods.COG variable were anterior-posterior directional COG and linear velocity of COG, vertical directional COG and linear velocity of COG. The data collections of this study were digitized by KWON3D program computed The data were standardized using cubic spline interpolation based by calculating the mean values and the standard deviation calculated for each variables. When performing the Air-rolling-breakfall, from the data analysis and discussions, the conclusions were as follows : 1. Anterior-posterior directional COG(APD-COG) when performing Air-rolling-breakfall motion, while PFO over to the vertical-hurdles(2m height) in judo. The range of APD-COG by forward was $0.31{\sim}0.41m$ in take-off position(event 1), $1.20{\sim}1.33m$ in the air-top position(event 2), $2.12{\sim}2.30m$ in the touch-down position(event 3), gradually and $2.14{\sim}2.32m$ in safety breakfall position(event 4), respectively. 2 The linear velocity of APD-COG was $1.03{\sim}2.14m/sec$. in take-off position(event 1), $1.97{\sim}2.22m/sec$. gradually in the air-top position(event 2), $1.05{\sim}1.32m/sec$. in the touch-down position (event 3), gradual decrease and $0.91{\sim}1.23m/sec$. in the safety breakfall position(event 4), respectively. 3. The vertical directional COG(VD-COG) when performing Air-rolling-breakfall motion, while PFO to the vertical-hurdles(2m height) in judo. The range of VD-COG toward upward from mat was $1.35{\sim}1.46m$ in take-off position(event 1), the highest $2.07{\sim}2.23m$ in the air-top position(event 2), and after rapid decrease $0.3{\sim}0.58m$ in the touch-down position(event 3), gradual decrease $0.22{\sim}0.50m$ in safety breakfall position(event 4), respectively. 4. The linear velocity of VlJ.COG was $1.60{\sim}1.87m/sec$. in take-off position(event 1), $0.03{\sim}0.08m/sec$. gradually in the air-top position(event 2), $-4.37{\sim}\;-4.76m/sec$. gradual decrease in the touch-down position(event 3), gradual decrease and -4.40${\sim}\;-4.77m/sec$. in safety breakfall position(event 4), respectively. When performing Air-rolling-breakfall showed parabolic movement from take-off position to air-top position, and after showed vertical fall movement from air-top position to safety breakfall. In conclusion, Ukemi(breakfall) is safety fall method Therefore, actions need for performing safety fall movement, that decrease and minimize shock and impact during Air-rolling-breakfall from take-off board action to air-top position must be maximize of angular momentum, and after must be minimize in touch-down position and safety breakfall position.