• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.123-125
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• 2013

우리는 흔히 골프 클럽의 휘둘러 골프공이 맞아 나가는 것을 보게 된다. 본 논문에서는 골프채 헤드가 골프공을 일정속도로 움직여 치고 난 후 골프채의 헤드는 같은 방향으로 일정 속도로 움직일 때 골프공을 치고 날아가는 골프공의 속도를 구한다. 골프공을 치기 전의 속도가 각각 다를 경우의 골프공의 속도를 각각 구한다. 골프를 칠 때 헤드의 속도, 골프공의 질량, 임팩트, 임팩트 후의 날아가는 속도, 그리고 임팩트 후의 이동 방향 등을 쉽게 알아보도록 하는 것이 본 논문의 목적이다.

• Journal of the Korea Society of Computer and Information
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• v.11 no.5 s.43
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• pp.53-58
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• 2006

In this paper, I propose an image based feature extraction method for an automatic golf swing analysis. While most swing analysis systems require an expert like teaching professional, the proposed method enables an automatic swing analysis without a professional. The extracted features for swing analysis include not only key frames such as addressing, backward swing, top, forward swing, impact, and follow-through swing but also important positions of golfer's body parts such as hands, shoulders, club head, feet, knee. To see the effectiveness of the proposed method. I tested it for several swing pictures. Experimental results show that the proposed method is effective for extracting important swing features. Further research is under going to develop an automatic swing analysis system using the proposed features.

• Korean Journal of Applied Biomechanics
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• v.24 no.4
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• pp.339-347
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• 2014

The purpose of this study was to investigate joint torques of lower body segments on professional golfers. Three dimensional swing analysis was conducted on the seven subjects. Each subject was asked to swing with 45 inches of Callaway driver, where two force plates (9286AA, Kistler, Switzerland) were built, with his normal speed and tempo. The resultant joint moments of the lower extremities were computed using the kinematic variables of the segments, anthropometric measures and the ground reaction force data by inverse dynamics method. Based on the results of this study, the following conclusions were drawn; It was found that the left ankle joint torque at 3rd phase was increased toward extension on the X-axis and abduction on the Y-axis. The left knee joint torque was alternated from flexion to extension direction in order to lower down the body weight at the beginning of the downswing. The lumbar joint torque was alternated from flexion to extension in order to speed up the upper body rotation which could increase the club head speed ultimately.

• Korean Journal of Applied Biomechanics
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• v.15 no.3
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• pp.71-78
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• 2005

The purpose of this research was to conduct an analysis on the factors that determine the distance at the time of target swing based on the use of late hitting of outstanding college golfers to verify the difference between late hitting and the distance that target increases in regular swing and the distance. Then, this research conducts an analysis on the correlation between club head velocity, ball velocity, launch angle, back spin, meet ratio and distance that become kinematics variables at the time of target swing. To attain the above mentioned purpose, 25 outstanding college players with average experience and handicap of 6 years and 5, respectively, were targeted Comparative analysis on two swing that target increase in regular and the distance was conducted by used driver. When it pertained to two types of swing. analysis system comprised of an analytical software called the Science Eye of the Bridgestone and peripheries was used to define the relationship between variables of club head velocity, ball velocity, launch angle, back spin, meet ratio that become kinematics variables. As for the method of processing data pertaining to the factors that determine the distance, differences of distance by the type of swing was verified by using independent T-test that leveraged SPSS 120 statistics program. Moreover, level of correlation between variables that contribute to the increase in distance through relation of correlation, and analysis of tendencies was conducted to analyze tendency of non-distance to increase in accordance to the increase of each variable. Key results produced through this experiment are as follows: 1. Artificial late hitting for increased non-distance that targets skilled players had effect on increased the distance(p<. 05). 2 The drive distance is correlated with each measured variable that is positive correlation to ball velocity, club head velocity, meet ratio and relation of back spin and launch angle are negative correlation. ball velocity and club head velocity are very high correlated with drive distance(p<.01), back spin and distance are negative correlation(p<.01). 3. Among each measured variable increasing the club velocity is the most contribution, and ball velocity and meet ratio and the increasing launch angle and back spin is negative effect for increasing distance.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.598-603
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• 2016

현대의 스포츠는 과학기술의 발전과 함께 성장하고 있고 골프종목 역시 재료역학적, 공기역학적 발전에 따라 비거리를 점점 늘려가고 있다. 하지만 현재까지의 비거리에 대한 연구는 골프공과 골프채의 재료의 변화와 딤플이 있는 골프공의 공기역학적 연구에 집중해 있었고 요즘에 들어서야 클럽헤드의 공기역학적 형상에 대한 연구가 활발히 진행되고 있다. 본 연구에서는 골프 경기 중 가장 먼 비거리를 만들어 내는 골프채인 드라이버의 단순화된 2차원 클럽헤드 형상을 설정하고 항력을 줄일 여러 가지 방법을 적용하여 최소의 항력을 갖는 헤드 형상을 찾아보았다. 연구결과 $10.2^{\circ}$의 로프트를 갖는 클럽헤드는 chord 길이가 face 높이의 3.2배이고, trailing edge가 face의 중심보다 전체 face높이의 10% 아래에 있을 때 가장 적은 항력을 얻을 수 있었다. 결과적으로 이 형상과 기존형상의 스윙 속도 차는 약 2mph로 5yard의 비거리 차이를 가져온다.

• Korean Journal of Applied Biomechanics
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• v.12 no.1
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• pp.205-219
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• 2002

This research seeks to identify the plantar pressure distribution graph and change in force in connection with effective golf drive strokes and thus to help ordinary golfers have appropriate understanding on the moving of the center of weight and learn desirable drive swing movements. To this end, we conducted surveys on five excellent golfers to analyze the plantar pressure applied when performing golf drive strokes, and suggested dynamic variables quantitatively. 1) Our research presents the desire movements as follows. For the time change in connection with the whole movement, as a golfer raises the club head horizontally low above ground from the address to the top swing, he makes a semicircle using the left elbow joint and shaft and slowly turns his body, thus lengthening the time. And, as the golfer twists the right waist from the middle swing to the impact with the head taking address movement, and does a quick movement, thus shortening the time. 2) For the change in pressure distribution by phase, to strike a strong shot with his weight imposed from the middle swing to the impact, a golfer uses centrifugal force, fixes his left foot, and makes impact. This showed greater pressure distribution on the left sole than on the right sole. 3) For the force distribution graph by phase, the force in the sole from the address to halfway swing movements is distributed to the left foot with 46% and to the right foot with 54%. And, with the starting of down swing, as the weight shifts to the left foot, the force is distributed to the left sole with 58%. Thus, during the impact and follow through movements, it is desirable for a golfer to allow his left foot to take the weight with the right foot balancing the body. 4) The maximum pressure distribution and average of the maximum force in connection with the whole movement changed as the left (foot) and right (foot) supported opposing force, and the maximum pressure distribution also showed much greater on the left sole.

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.217-225
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• 2019

The aim of this study was determine to effect of shaft length and physical condition on golf driving performance(head speed, distance and direction). A range of drivers with length between 44 inch, 45 inch and 46 inch limit imposed by R&A rules limited were assembled and evaluated. Club head speed and drive distance and accuracy were determined three category 27 PGA pro golfer (handicaps 0, and height $170cm{\geq}171-175{\geq}175-180cm$) who golf performance. As a results follow : Head speed was significantly difference with 44, 45 between 46inch(p<.01). Distance was significantly difference with 44 between 46inch(p<.05). And direction was significantly difference with 44, 45inch between 46inch(p<.05). Head speed according to height was general similarity among shaft length in 170cm, 171-175cm. Distance were general similarity among shaft length in 170cm, and significantly difference with 44inch between 46inch in 171-175cm(p<.01), and significantly difference with 45inch between 46inch in 176-180cm(p<.05). Direction were significantly difference with 44inch between 46inch in 170cm(p<.05), but do not significantly difference with 44inch between 46inch in 176-180cm, 176-180cm. These results show that shaft length and height can affect head speed, distance and direction.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.532-542
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• 2021

The purpose of this study was to investigate the body's strategy through kinematic variables of the lower extremities and ground reaction forces to maintain the club-head speed and ball accuracy despite the three stances during the golf swing. Ten male golfers who official handicap two were participate in the experiment. All subjects performed swing after maintaining the address posture according to stance conditions(square; SS, open: OS, closed: CS). Using a 3D motion analysis system and force plateform, the results were calculated with the 7-iron full swing each stance. In result, there was no difference in center of displacement, and left and right hip and knee joint angle displacement. Left ankle joint was largely plantar-flexed in OS, and right ankle joint was largely performed in CS from the address to the downswing. From address to take-back, right foot had a large left direction and the left foot had a right direction were greater in OS than in CS. Therefore, despite various stances, maintaining the same posture at impact is thought to have a positive effect on club head speed and ball direction.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.6
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• pp.29-35
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• 2001

The cutting characteristics of Ti-6Al-4V alloy and total wear when machining Ti-6Al-4V alloy was studied to understand the machining characteristics. This material is one of the strong candidate materials present and future aerospace or met ical applications. Nowadays their usage has already been broaden to commercial applications such as golf club head, finger rings and many decorative items. Anticipating the general use of this material and development of the titanium alloy in domestic facilities, the review and the study of the machining parameters far those alloys are deemed necessary. This study is concentrated to the machining parameters of the Ti-6Al-4V alloy due to their dominant position in the production of tita mum alloys.

• Korean Journal of Applied Biomechanics
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• v.19 no.2
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• pp.323-336
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• 2009

The purpose of the current study was to research scientific basis and necessity of supplementary materials for field lesson out of golf swing teaching methods. As the subject of study, skillful tour pro golfers were chosen to reinterpret field lesson results for driver swing from the viewpoint of kinematics. In addition, through precise analysis, this study developed a case to verify the validity and error of field lesson. As a result, field lesson showed a slight difference among qualitative evaluation of kinematical analysis of techniques, subjects of study, and items. Accordingly, there was a little difference between two methods in view of evaluation of errors that 5 subjects of the study have shown. However, there was a significant difference in compensation to prevent causes of error and errors. Based on instructor's experience most errors could be evaluated. Therefore, feedback for error correction based on instructor's experience showed a significant difference from qualitative evaluation of kinematical analysis of techniques. In conclusion, the following are required for correct golf swing lesson; instant feedback through field lesson and qualitative evaluation of kinematical analysis of techniques to determine fundamental causes correctly.