• 한국운동역학회지
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• 제22권3호
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• pp.269-276
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• 2012

The purpose of This study's aim is to examine the difference in the changes of body segment movement, variables for ball quality, and carry at golf driver swing according to the ball quality using comparative analysis. Regarding the impact variables according to the ball quality using the track man and carry, club speed was the fastest at draw shot, ball speed was the fastest at straight shot, and smash factor was the lowest at draw shot. About the vertical launch angle, the fade shot showed the highest launch angle while the max height of the ground and ball was the highest at fade shot. And carry was the longest at draw shot. For the flight time, it was the longest at draw shot. The landing angle was the largest at fade shot. About the club head position change and trajectory, at the overall event point, the fade shot drew a more outer trajectory at the point of the follow through(E6) than the straight or draw shot. Regarding the angular speed of shoulder rotation, at the overall event point, the fade shot showed the greatest angular speed change in the follow through(E6). Also, about the angular speed of pelvic rotation, at the overall event point, the draw shot showed the greatest angular speed change at the point of down swing(E4). Concerning the stance angle change, both straight and fade shots were open as the concept of open stance whereas the draw shot was close as that of close stance. Regarding the previous study, the most important factor of deciding Ball Quality is the club face angle's open and close state at Impact. In short, the Ball Quality and carry were decided by this factor.

• PNF and Movement
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• 제18권3호
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• pp.435-444
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• 2020

Purpose: This study aimed to compare the elector spine muscle tone using the irradiation of the proprioceptive neuromuscular facilitation (PNF) arm pattern according to angular motion. Methods: Thirty subjects participated in this study. Elector spine muscle tone was measured using a Myotonpro device while in the sitting position according to the angular motion (70°, 100°, 130°) of the PNF arm pattern using a D1 flexion pattern. Each angular motion of the PNF arm pattern was performed with a continuous passive motion (CPM). The change in elector spine muscle tone was statistically evaluated using a repeated one-way ANOVA test. Post-hoc analysis was performed using the Bonferroni method. Results: The results revealed a significant change in elector spine muscle tone when performing the PNF arm pattern using D1 flexion pattern. Specifically, the elector spine muscle tone had significantly increased at 100° and 130° motion in the PNF arm pattern when compared to the initial muscle tone (p < 0.05). No significant muscle tone changes were noted for any of the angular motions of the PNF upper arm pattern (p > 0.05). Conclusion: The results of this study indicate a positive increase in elector spine muscle tone with irradiation of the PNF upper arm pattern exercise with 100° or 130° angular motion. The minimum angle at which the effect of the irradiation of the PNF arm pattern could be seen was 100°.

• 제어로봇시스템학회논문지
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• 제15권2호
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• pp.184-191
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• 2009

The common requirements of rough terrain mobile robots are long-term operation and high mobility in rough terrain to perform difficult tasks. In rough terrain, excessive wheel slip could cause an increase in the amount of dissipated energy at the contact point between the wheel and ground or, even more seriously, the robot could lose all mobility and become trapped. This paper proposes a traction control algorithm that can be independently implemented to each wheel without requiring extra sensors and devices compared with standard velocity control methods. The proposed traction algorithm is analogous to the stick-slip friction mechanism. The algorithm estimates the slippage of wheels by angular acceleration change, and controls the increase or decrease state of torque applied to wheels Simulations are performed to validate the algorithm. The proposed traction control algorithm yielded a 65.4% reduction of total slip distance and 70.6% reduction of power consumption compared with the standard velocity control method.

• Journal of Mechanical Science and Technology
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• 제19권6호
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• pp.1253-1267
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• 2005

Misalignment can be an important problem in the integration of GPS/INS. Observability analysis of the alignment errors in the integration of low-grade inertial sensors and multi-antenna GPS is presented in this paper. A control-theoretic approach is adopted to study the observability of time-varying error dynamics models. The relationship between vehicle motions and the observability of the errors in the lever arm and relative attitude between GPS antenna array and IMU is given. It is shown that alignment errors can be made observable through maneuvering. The change of acceleration makes the components of the relative attitude error that are orthogonal to the direction of the acceleration change observable. The change of angular velocity makes the components of the lever arm error that are orthogonal to the direction of the angular velocity observable. The motion of constant angular velocity has no influence on the estimation of the lever arm.

• 패션비즈니스
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• 제23권1호
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• pp.116-126
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• 2019

The purpose of this study is to objectify the shape of curvature and average change rate of angular and arched eyebrow makeup. The data for the analysis were the final 336 pieces for the cosmetology students in the whole country. SPSS 20.0 program was used for the collected data, frequency analysis, factor analysis, reliability analysis, and crossover analysis were performed. First, the frequency of the average change rate of eyebrow makeup (angular and arcuate) was analyzed. As a result, the eyebrows suitable for the angled type showed the highest level of 'A-2' and the arched eyebrows had the highest level of 'B-2'. Second, to analyze the important factors of eyebrow makeup, frequency of eyebrows was the most important, followed by the inclination of eyebrows and eyebrow tail. Third, factor analysis and reliability analysis were conducted to examine each dimension of eyebrow makeup perception, and it was derived from three factors including acceptability, aggressiveness, and playability. Fourth, in order to analyze the difference of important factors in the form of the standard eyebrow makeup, the cross - analysis was performed with chi - square test, and it was confirmed that the angular eyebrow makeup showed the most objectivity when the average change rate was 0.29 and the curvature was 0.67. Fifth, arcuate eyebrow makeup showed the most objectivity when the average change rate was 0.57 and curvature was 0.56. The results of this analysis can be used as objective data of aesthetic criteria when designing the eyebrow shape.

• The Journal of Korean Physical Therapy
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• 제17권3호
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• pp.429-440
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• 2005

The purpose of this study was to compare the effects of knee joint position sense following local and general load protocols in 25 healthy male subjects. Proprioception of the knee joint was evaluated by measuring absolute angular errors at matching angles before, after and between 2 different types of load protocols. Proprioception tests(on the dominant knee) were performed in which proprioception of the passivepassive reproduced and active-active reproduced knee position was measured. Local load was provided with maximum isokinetic knee extension-flexion on the isokinetic dynamometer(Cybex), and general load was 10 minutes running on a treadmill. Peak torque(knee extension and flexion) and heart rate(beats per minute) was evaluated as an indicator of local and general fatigue during load protocols. The results were as follows: 1. For pasive-pasive reproduced knee position test, significant difference in absolute angular errors after general load protocol was detected compared with that before general load protocol(P<.05), significant difference in absolute angular errors after local load protocol was detected compared with that before local load protocol(P<.05). However, no significant difference in absolute angular errors of general load protocol was detected compared with that of local load protocol (P>.05), no significant difference in absolute angular errors of local load protocol was detected compared with that of general load protocol(P>.05). 2. For active-active reproduced knee position test, significant difference in absolute angular errors after general load protocol was detected compared with that before general load protocol(P<.05), significant difference in absolute angular errors after local load protocol was detected compared with that before local load protocol (P<.05). Also, significant difference in absolute angular errors of general load protocol was detected compared with that of local load protocol(P<.05), significant difference in absolute angular errors of local load protocol was detected compared with that of general load protocol(P<.05). 3. A significant decrease of peak torque of knee extensors and flexors was seen after local load, although heart rate was significantly increased(P<.05). No significant change of peak torque of knee extensors and flexors was seen after general load(P>.05), although heart rate was also significantly increased(P<.05). The previous study revealed that knee proprioception is significantly altered when the muscle mechanoreceptors are dysfunctional due to muscle fatigue, although the joint mechanoreceptors have no significantly effect on knee proprioception when the presence of knee muscle fatigue. However, the results of this study are different from those of the previous study in that muscle weakness of the knee could not be seen after general load. This study shows that general load may diminish motor control by the central nervous system. Proprioceptional decline without muscle weakness of knee after general load suggests a change in the proprioceptional pathway without influence from muscle mechanoreceptors.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.664-669
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• 2000

Angular misalignment is one of the important causes for shaft vibration of turbine-generator in 1000MW nuclear power plant. It may cause the plant unexpected shutdown and subsequent accident. The change of dynamic characteristics in journal bearing and rotor due to angular misalignment in high pressure turbine is analyzed. The stiffness/damping coefficients of journal bearing increase as angular misalignment. Subsequently the natural frequency of HP turbine is changed. It was found that the natural frequency may locate near 2 times operating frequency in case of severe misalignment.

• 대한조선학회 특별논문집
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• 대한조선학회 2007년도 특별논문집
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• pp.22-25
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• 2007

Angular distortion in welding process is decided by the various variables. We can make the prediction of welding distortion in similar reality by the analysis of data through many specimen tests. However it is difficult that prediction of welding distortion applies to the ship building. We can establish that angular distortion varies directly as the specimen size. And, it makes clear distortion's difference between constraint and unconstraint, according to the change of a plate thickness.

• 설비공학논문집
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• 제8권3호
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• pp.413-422
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• 1996

Freezing of water in von-$K{\acute{a}}rm{\acute{a}}n$ swirling flow is considered. The transient behavior of the temperature distribution in both solid and liquid phases and freezing rate are determined. The fluid flow induced by the rotation of solid strongly inhibits the freezing process. The thickness of frozen layer is inversely proportional to the square root of the angular velocity of solid. As the angular velocity or initial liquid temperature becomes larger, the freezing process is more strongly inhibited by the fluid flow. When phase change is present, the transient heat transfer rate is greater than the case with no phase change.

• 한국운동역학회지
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• 제21권1호
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• pp.39-46
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• 2011

The purpose of this study was to examine differences between players who bend the left elbow and those who stretch it during the forward swing from BST to BC in a 2-handed backhand stroke among outstanding high school tennis players, and to assess the detailed 3D rotational kinematic characteristics of the shoulder and the hip. Statistically significant differences were observed between groups in the longitudinal axis rotation angle of the shoulder and the angle between the shoulder and the arm at BST, and in the side to side movement of the shoulder, the up and down movement of the hip, the side tilt angular velocity of the shoulder, the side tilt angular velocity of the hip, and the front tilt angular velocity of the hip at BC. The difference in the longitudinal axis rotation angle of the shoulder between the 2 groups suggests a difference in the flexibility of the joint in the shoulder arm racquet system. The longitudinal axis rotation angular velocity of the shoulder reached its peak at 75 % of the duration of the analyzed segment and then decreased little by little until BC. This time is considered the stage for increasing the angular velocity of the upper arm, the forearm, the hand and then the racquet, which are more distal segments than the shoulder.