• The korean journal of orthodontics
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• v.20 no.3 s.32
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• pp.553-564
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• 1990

The purpose of this study was to compare mandibular teeth development of Angle Class I malocclusion group with that of Angle Class III malocclusion group. The studied subjects consisted of 217 Angle Class I malocclusion patients and 235 Angle Class III malocclusion patients. Two study methods were used. One was to evaluate tooth development degree by means of Nolla stage method, the others was to measure tooth length on panoramic radiograph. The following results were obtained, in 7, 8 and 9 years, tooth development of Angle Class III malocclusion group was significantly faster than that of Angle Class I malocclusion group. in 6 year and 10, 11, 12, 13, 14 years, the difference of tooth development degree between Angle Class III malocclusion group was not significant.

• Transactions on Electrical and Electronic Materials
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• v.9 no.3
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• pp.120-122
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• 2008

We have studied the tilt angle generation on the homeotropic polyimide (PI) surface using a low intensity ion beam source as a function of incident angle. An excellent LC alignment of nematic liquid crystal (NLC) on the PI surface with ion beam exposure for all incident angles was observed. The tilt angle of NLC on the homeotropic PI surface for all incident angles was from 90 to 88 degree was observed. Also the tilt angle of NLC on the homeotropic PI surface with ion beam exposure of 400 eV had a tendency to increase as ion beam energy incident angle become more instance from 45 degree. Finally, a good LC alignment thermal stability on the homeotropic PI surface with ion beam exposure can be achieved.

• Journal of the Ergonomics Society of Korea
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• v.18 no.1
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• pp.91-108
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• 1999

In our previous work using a motion analyzer and 3-dimensional sonic digitizer, the arm shapes for 23 women in their early twenties were classified into three characteristic types. In order to design sleeves, suitable for arm movements for the three characteristic arm shapes, a relationship between arm length variation and shoulder/elbow angles has been investigated for four cases of arm movements (flexion, extension, adduction and abduction). Each arm movement can be characterized by the changes in shoulder angle and the changes in elbow angle at the maximal shoulder angle. In all the four cases of arm movements, the changes of shoulder length and cap height are largest at the maximal shoulder angle. These changes were little affected by changes in elbow angle. The changes in the lower arm length and the difference between cap height and upper arm length are the largest at the maximal elbow angle of the maximal shoulder angle. There is a linear relationship between cap height and shoulder angle during arm movements; thus, in designing sleeves the cap height can be determined from the regression of cap height vs. shoulder angle.

• Journal of Institute of Control, Robotics and Systems
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• v.7 no.12
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• pp.1044-1050
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• 2001

This paper presents firstly the method of Euler angle matching designing the transfer alignment using the attitude matching. In this method, the observation directly uses Euler angle difference between MINS and SINS so it needs to describe the rotation vector error to the Euler angle error. The rotation vector error related to the Euler angle error is derive from the direction cosine matrix error equation. The feasibility of the Kalman filter designed for the transfer alignment by Euler angle matching is analyzed by the alignment error results with respect to the roll angle the pitch angle, and the yaw angle matching.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.04a
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• pp.45-46
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• 2006

We have studied the viewing angle control using a twist nematic liquid crystal display (TN-LCDs). These TK-LCDs have the characteristics, of which is not good image quality, for examples low Contrast ratio and gray scale inversion problems at upper and down viewing direction. TN-LCDs have the function of switching between the wide viewing mode and narrow viewing angle mode using two tilted LC layers. Tilt angles of the two LC layers, $14^{\circ}$ and $60^{\circ}$ were required in both wide viewing angle and narrow viewing angle modes, respectively. Consequently, this device is compatible with two image performances of which the wide viewing angle mode and Narrow viewing angle mode.

• Journal of ILASS-Korea
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• v.26 no.1
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• pp.9-17
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• 2021

Six shear coaxial injectors with different recess length and taper angle were manufactured. Cold-flow tests on the injectors were performed at room temperature and pressure using water and air as simulants. By changing the water mass flow rate and air mass flow rate, spray images were taken under single-injection and bi-injection. Breakup length and spray angle were analyzed from instantaneous and averaged spray images using image processing techniques. For all the injectors, the breakup length generally decreased as the momentum flux ratio increased at the same gas mass flow rate. The injectors with 7.5° taper angle usually had the longest breakup length and the smallest spray angle. When the taper angle was 15° or more, it hardly affected breakup length and spray angle. The recess length did not influence breakup length but its effect on spray angle depended on the taper angle.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.691-694
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• 2021

The malalignment of the trunk causes abnormal stress in a specific area and lead to trunk instability. The purpose of this study was to investigate the correlation between the angle between the infrasternal angle and the trunk side shift distance. The participants in this study 22 subjects were participated. The infrasternal angle and trunk side shift distance were measured using a camera and analyzed using the Image J program. The correlation between the asymmetry of the infrasternal angle and trunk side shift distance was moderate (r=-0.413; p=0.028). According to the asymmetry of the infrasternal angle, it was confirmed that trunk lateral shift appeared in a specific direction. Based on result, it suggests that infrasternal angle and trunk side shift should be considered in the intervention plan of patients with asymmetry of the infrasternal angle.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.2
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• pp.25-31
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• 2004

Machinability in metal cutting processes depends on cutting input conditions such as cutting velocity, feed rate, depth of cut, types of work material and tool shape factors. In this study, to assess chip breaking characteristics of a turning process, an equivalent oblique cutting system to this has been established. And the equivalent effective rake angle was determined using side rake angle, back rake angle and side cutting edge angle of the tool. A non-dimensional parameter, Chip breaking index(CB), was used to assess Chip breaking characteristics of chip in conjunction with the equivalent effective rake angle. In case of positive rake angles of the equivalent effective rake, the back rake angle has little effect on the chip breaking characteristics however, in case of negative ones, the side rake angle has some effect on Chip breaking characteristics.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.1
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• pp.75-83
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• 2017

Purpose : The parameters used in architectural analysis are muscle thickness, fascicle length, pennation angle, etc. Pennation angle is an important muscle characteristic that plays a significant role in determining a fascicle's force contribution to movement. Ultrasonography has been widely used to obtain the image for measurement of a pennation angle since it is non-invasive and real-time. However, manual assessment in ultrasonographic images is time-consuming and subjective, making it difficult for using in muscle function analysis. Thus, in this study, I proposed an automatic method to extract the pennation angle from the ultrasonographic images of gastrocnemius muscle. Method : The ultrasonographic image obtained from 10 healthy participants's gastrocnemius muscle using for developed automatic measuring program. Automatic measuring program algorithm consists with preprocessing, line detection, line classification, and angle calculation. The resulting image was then used to detect the fascicles and aponeuroses for calculating the pennation angle with the consideration of their distribution in ultrasonographic image. Result : The proposed automatic measurement program showed the stable repeatability of pennation angle calculation. Conclusion : This study demonstrated that the proposed method was able to automatically measure the pennation angle of gastrocnemius, which made it possible to easily and reliably investigate pennation angle more.

• Journal of Korean Medicine Rehabilitation
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• v.27 no.4
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• pp.121-130
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• 2017

Objectives This study was designed to investigate the correlation between the gait analysis indices and Lumbar X-ray indicators. Methods 21 cases of patients who received treatment from October 2013 to February 2017 for abnormal posture were analyzed. Three indicators were measured in the lumbar spine X-ray. These indicators include Ferguson's angle, Lumbar lordotic angle, L4-5 IVD angle. Gait analysis indices were estimated by Treadmill Gait Analysis system. The data were analyzed to find out correlation between the gait analysis indices and Lumbar X-ray indicators. Spearman correlation was used. Results Ferguson's angle and Difference of gait balance of front and rear had a negative linear relationship, but there was no statistical significance. Lumbar lordotic angle and Difference of gait balance of front and rear had a negative linear relationship, but there was no statistical significance. L4-5 IVD angle and Difference of gait balance of right and left had a negative linear relationship, but there was no statistical significance. Conclusions Difference of gait balance of front and rear had strong level of a negative linear relationship with Ferguson's angle and Lumbar lordotic angle.