• 한국운동역학회지
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• 제13권1호
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• pp.63-72
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• 2003

This study is examine and analysis of the most flying and run distance during swing three times with six balls between two amateurs and pro-golfers in golf field in Sungnam airport. During down swing, kinetics variances are velocity of club-head and balls, vertical angular velocity. this scientic data present amateur golfers with recognition of long flying distances for golf balls. Through this study, the conclusions are as follows. 1. Before impact the balls, The club-head velocity of amateur golfers and pro-golfers show 33.34 - 39.53m/s, 39.04 - 42.82m/s respectively during the down swing. But The club-head velocity, flight and Run distances comparative $K_1$ amateur golfer with the pro-golfer are similar. 2. After impact the balls, The balls velocity if amateur golfers show 53.04 - 61.57m/s, The pro-golfers show 62.32 - 63.4m/s respectively during the down swing. In case of $K_3$,$K_4$, After the impact balls velocity comparative The RA brand with other brand are similar, Flight and Run distance are difference. 3. After impact the balls, The balls velocity are difference to other brand but The long flight and Run distance arrange RA, BIG, TITL. 4. In the vertical flight angle of the ball after impact, amateur golfer showed 16.75 - $18.73^{\circ}$. The pro-golfer showed 15.03 - $16.04^{\circ}$. In the vertical flight angle of the balls ideal $12-13^{\circ}$, The long flight and Run distance approach In the vertical flight angle the balls $12-13^{\circ}$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.477-482
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• 2001

To realize higher track density of HDD, the servo bandwidth should be higher, however, is limited by the mechanical resonances of the arm, coil of the VCM and ball bearing pivot. The dual-stage actuator systems have been suggested as a possible solution. For the dual-stage actuator systems based on the suspension, the suspension resonance frequencies in the radial access direction are important factors to increase a servo bandwidth, however the improvement of these frequencies may affect the shock resistance performance and spring constant. The slider's flying stability can be deteriorated by the change of a vertical stiffness. In this work, we have investigated a suspension design scheme possessing a milliactuator for dual-stage actuator systems and also achieved higher mechanical characteristics. Design parameters are deduced by finite element analysis with sensitivity function. It is confirmed that the proposed suspension with the milliactuator has the capability of fine tracking motion, due to its hinge structure on the spring region, and achieves higher mechanical resonance frequencies in the radial access direction with a high-shock resistance and a low-spring constant.

• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 2부
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• pp.810-814
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• 2006

그 동안 개발된 시뮬레이터들은 주로 단안 정보에 기초한 것들이 대부분이었고, 양안 정보를 제공하더라도 사용자의 움직임을 반영하지 못하였다. 양안정보를 제공하지 못하는 시뮬레이터는 게임으로써는 재미에 한계가 있고, 훈련 도구로써 실제 수행에 도움을 주기 어렵다. 본 연구는 사용자의 움직임을 고려한 양안 정보를 제공하는 외야수 뜬 공 잡기 가상 현실 시뮬레이터를 개발하여 이러한 문제점들을 해결할 수 있는 토대를 마련하였다. 그리고 양안 정보 제공의 중요성과 개발된 시뮬레이터의 타당성 및 유용성을 검증하기 위해 본 시뮬레이터를 이용하여 공의 위치 판단 과제를 실시하였다. 양안 시차가 주어진 조건과 주어지지 않은 조건 각각에 두 집단 구성원들을 무선적으로 배치하여 정답률과 반응 시간을 측정하였다. 숙련자들은 양안시차가 주어진 조건에서 더 좋은 수행을 보인 반면, 일반인들은 양안시차가 주어지지 않은 조건에서 더 좋은 수행을 보였다. 이는 뜬 공 잡기 상황에서 양안정보가 숙련자들에게는 유용하지만 비숙련자들에게는 그렇지 않았음을 보여준다. 또한 숙련자들이 정답률과 반응 시간 모두에서 일반인들보다 더 좋은 수행을 보였고 이는 통계적으로 유의미하였다. 이와 같은 가상 현실 시뮬레이터는 양안 정보를 제공함으로써 이전의 시뮬레이터들보다 게임이나 훈련 도구로 사용함에 있어 더 효과적이다. 또한 인간의 운동 수행에 관련된 연구를 하는데 유용하게 사용될 수 있다.

• 대한물리의학회지
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• 제13권4호
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• pp.59-65
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• 2018

PURPOSE: The purpose of the present study is to investigate the changes in the cognitive function of elderly dementia patients residing in a residential care facility, following six weeks of brain-computer interface (BCI)-based cognitive training and to determine whether BCI-based cognitive training effectively improves their cognitive functions. METHODS: Thirty subjects diagnosed with dementia were randomly assigned to either the experimental or control group. Pre- and post-test cognitive function assessments were conducted using the mini mental state examination-Korean (MMSE-K) and Korean-dementia rating scale (K-DRS). The experimental group received BCI-based cognitive training, which consisted of games such as flying a ball and exploding a bomb, while the control group participated in music listening activities and National Health Gymnastics. Both groups engaged in a total of 18 sessions (3 times per week for 6 weeks, for 40 minutes per session). RESULTS: After 6 weeks of intervention, the experimental group had significantly increased MMSE-K scores ($19.53{\pm}1.30$ to $22.20{\pm}1.15$; p<.0011) and total K-DRS scores ($87.20{\pm}4.16$ to $99.33{\pm}1.15$; p<.0011). In addition, the experimental group showed greater cognitive improvements than the control group. CONCLUSION: The results of this study suggest that BCI-based cognitive training is a positive intervention tool for improving the cognitive function of dementia patients.

• 한국운동역학회지
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• 제15권1호
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• pp.29-44
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• 2005

The purpose of this study is to reveal the effects of two different kicks, the drop kick and the punt kick, into the kicking motion, through the kinetic comparative analysis of the kicking motion, which is conducted when one kicks a soccer goal. To grasp kinetic changing factors, which is performed by individual's each body segment, I connected kicking motions, which were analyzed by a two dimension co-ordination, into the personal computer to concrete the digits of it and smoothed by 10Hz. Using the smoothed data, I found a needed kinematical data by inputting an analytical program into the computer. The result of comparative analysis of two kicking motions can be summarized as below. 1. There was not a big difference between the time of the loading phase and the time of the swing phase, which can affect the exact impact and the angle of balls aviation direction. 2. The two kicks were not affected the timing and the velocity of the kicking leg's segment. 3. In the goal kick motion, the maximum velocity timing of the kicking leg's lower segment showed the following orders: the thigh(-0.06sec), the lower leg(-0.05sec), the foot(-0.018sec) in the drop kick, and the thigh(-0.06sec), the lower leg(-0.05sec), the foot(-0.015sec) in the punt kick. It showed that whipping motion increases the velocity of the foot at the time of impact. 4. At the time of impact, there was not a significant difference in the supporting leg's knee and ankle. When one does the punt kick, the subject spreads out his hip joint more at the time of impact. 5. When the impact performed, kicking leg's every segment was similar. Because the height of the ball is higher in the punt kick than in the drop kick, the subject has to stretch the knees more when he kicks a ball, so there is a significant affect on the angle and the distance of the ball's flying. 6. When one performs the drop kick, the stride is 0.02m shorter than the punt kick, and the ratio of height of the drop kick is 0.05 smaller than the punt kick. This difference greatly affects the center of the ball, the supporting leg's location, and the location of the center of gravity with the center of the ball at the time of impact. 7. Right before the moment of the impact, the center of gravity was located from the center of the ball, the height of the drop kick was 0.67m ratio of height was 0.37, and the height of the punt kick was 0.65m ratio of height was 0.36. The drop kick was located more to the back 0.21m ratio of height was 0.12, the punt kick was located more to the back 0.28m ratio of height was 0.16. 8. There was not a significant difference in the absolute angle of incidence and the maximum distance, but the absolute velocity of incidence showed a significant difference. This difference is caused from that whether players have the time to perform of not; the drop kick is used when the players have time to perform, and punt kick is used when the players launch a shifting attack. 9. The surface reaction force of the supporting leg had some relation with the approaching angle. Vertical reaction force (Fz) showed some differences in the two movements(p<0.05). The maximum force of the right and left surface reaction force (Fx) didn't have much differences (p<0.05), but it showed the tendency that the maximum force occurs before the peak force of the front and back surface (Fy) occurs.

• Journal of Sport and Applied Science
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• 제5권2호
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• pp.23-29
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• 2021

Purpose: The purpose of the study is to review the current states of new sports imported from foreign countries and to discuss strategic insights for promoting new sports which has been invented in Korea. Research design, data, and methodology: This study employed the qualitative approach, in which reviewed a related literature. First, the study selected flying disc, sports stacking, and T-ball as sample cases. This is because these new sports were recognized the prominent sports frequently played in physical education classes in Korea. Second, the study reviewed prior studies in the field of distribution and marketing in order to determine the criteria of analysis and variables that frequently examined in distribution and marketing studies. Finally, the study confirmed such terminologies as research variables including new sport name, organization name, background of the invented sports, distributional channel, promotional activities and so forth. To collect data, the study search literature via academic search engine including DBpia, KISS, RISS, ScienceDirect, SAGE Journals, SpringerLink, and Taylor & Francis. Results: It was found that all of the imported new sports organized association and its nationwide branches to deliver their sprots to local schools and recreational markets. second, they targeted schools and sought to broaden their markets to recreational communities. Conclusions: In order to promote new sport invented in Korea, associations need to be systematically organized and mission should be clearly stated. In addition, creative methods for promotion need to be developed. Future directions were discussed.