• 한국표면공학회지
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• 제35권5호
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• pp.295-304
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• 2002

In this study, the effect of the diameter and the number of barrel hole on the total area of barrel hole were calculated and analyzed. And the effects of applied current density, rotational speed of the barrel, size and number of barrel hole, and the volume of plating materials on the distribution of plating thickness were experimented and discussed by the barrel electroplating of the tube type brass specimens in a sulfamate nickel barrel solution. The effect of barrel hole size and barrel hole area on the throwing power was also discussed.

• Clinics in Shoulder and Elbow
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• 제5권2호
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• pp.81-87
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• 2002

• 대한정형외과스포츠의학회:학술대회논문집
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• 대한정형외과스포츠의학회 2003년도 제14차 학술대회
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• pp.132-146
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• 2003

• 한국운동역학회지
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• 제21권5호
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• pp.639-644
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• 2011

The purpose of this study was to provide quantified data on the throwing skills of world-class athletes and to analyze the kinematic variables for women shot-putters at the IAAF World Championships Daegu 2011. Three-dimensional motion analyses of the eight players who qualified for the final round were carried out to obtain the data. The Kwon3D XP program was used for image analysis of the kinematic data, which included the configurations of each joint. The following conclusions were arrived at. The throwing distance increased with an increase in the release speed, and a significant correlation (p <. 01) was observed between the throwing distance and release speed. It was also shown that players using the spin technique increased their release speed with a fast shoulder-rotation-angle speed. The release height varied with their height and showed a significant difference with the record. This showed that the release angle did not greatly influence the record for the game, but varied with their technical and physical characteristics. Therefore, an increase in release speed is required to improve the record.

• 한국운동역학회지
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• 제20권4호
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• pp.429-436
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• 2010

The purpose of this study was to analyze the kinematic factors and throwing variables for the 3-turn and 4-turn techniques and for release as well as to provide technical advice for improving athletic performance in hammer throwing. Data analysis led to the following conclusions: To increase the rotation speed for the 3-turn and 4-turn techniques, the time elapsed during the 1-foot support period should be decreased the distance between the rotating foot and the rotation axis should be small and the height of the hip joint should be increased at the times of release The throwing angle at the moment of release should be more than 40 degrees, and the throwing position should be taken vertically high at the shoulder joints. To accelerate the motion of the hammer, the speed should not be reduced during the 1-foot support period but should be increased during the 2-foot support period for much greater acceleration. In the 3-turn technique, the angles of the shoulder axis and hummer string should be dragged angle at the maximum point and lead angle at the minimum point, and dragged angle at the maximum and minimum points in the 4-turn at the time of relase The upper body should be quickly bent backward, the knee angle should be extended, and the angles of the shoulder axis and hammer string should be dragged angle close to 90 degrees.

• Clinics in Orthopedic Surgery
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• 제10권4호
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• pp.468-478
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• 2018

Background: The restriction of wrist motion results in limited hand function, and the evaluation of the range of wrist motion is related to the evaluation of wrist function. To analyze and compare the wrist motion during four selected tasks, we developed a new desktop motion analysis system using the motion controller for a home video game console. Methods: Eighteen healthy, right-handed subjects performed 15 trials of selective tasks (dart throwing, hammering, circumduction, and winding thread on a reel) with both wrists. The signals of light-emitting diode markers attached to the hand and forearm were detected by the optic receptor in the motion controller. We compared the results between both wrists and between motions with similar motion paths. Results: The parameters (range of motion, offset, coupling, and orientations of the oblique plane) for wrist motion were not significantly different between both wrists, except for radioulnar deviation for hammering and the orientation for thread winding. In each wrist, the ranges for hammering were larger than those for dart throwing. The offsets and the orientations of the oblique plane were not significantly different between circumduction and thread winding. Conclusions: The results for the parameters of dart throwing, hammering, and circumduction of our motion analysis system using the motion controller were considerably similar to those of the previous studies with three-dimensional reconstruction with computed tomography, electrogoniometer, and motion capture system. Therefore, our system may be a cost-effective and simple method for wrist motion analysis.

• 한국재료학회지
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• 제11권10호
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• pp.820-832
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• 2001

In order to obtain the basic data on the optimum conditions of electroforming process for fabricating the micro wiring pattern for plate type micro- motor core, characteristics of plating bath and properties of deposits were studied with various copper plating baths which contain sulfate, fluoborate, pyrophosphate and cyanide salt, respectively. Cathodic polarization, throwing power, internal stress, texture and surface morphology of deposits were observed. Throwing power of plating solution is deeply related to the polarization curves and the values are in the range of +20∼20%. The order of values ate as follows- pyrophosphate, cyanide, sulfate and fluoborate bath. Internal stresses of deposits are tensile in all of the copper plating bath. Thickness of the deposits plated at the center of holes has the highest value in the pyrophosphate bath and K factor, ratio of height and width of deposit, is 1.44. It was confirmed that the pyrophosphate bath was the best one for the electroforming of wire pattern.

• 한국운동역학회지
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• 제30권2호
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• pp.165-172
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• 2020

Objective: The purpose of this study was to provide quantitative and objective data of throwing movement in baseball catcher through biomechanical analysis. Method: Eight high school baseball catchers (age: 17.3±0.7 yrs, height: 175.3±4.5 cm, weight: 82.5±9.0 kg, Career: 7.4±2.1 yrs) participated and 3-dimentional motion capture system and electromyography (EMG) were used in this study. Results: The maximum center of mass position displacement was observed in forward direction. The linear velocity magnitude of the upper extremity segments were showed as "wrist>elbow>shoulder" which is indicative of kinematic chain. For kinetic EMG data, we also observed the greater muscle activation in the left brachioradial and erector spine muscles muscle that during throwing movement. Conclusion: We expect that biomechanical data from this study will provide important training implications to baseball coaches and trainers in order to effectively train their baseball catchers.

• 한국운동역학회지
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• 제18권2호
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• pp.125-139
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• 2008

본 연구는 선천적 시각장애인과 후천적 시각장애인 그리고 정안 인을 대상으로 운동학적 특징을 비교 분석해보아, 시각장애인들의 운동지도와 운동능력의 향상 그리고 부상방지를 목적으로 한다. 비디오카메라는 3대를 사용하여 촬영속도는 60field/sec로 하였으며 가장 멀리 던진 자세를 선택하여 Kwon 3D ver. 3.1프로그램으로 자료를 분석 하였다. 실험의 결과는 1. 릴리스 시의 공의 속도는 정안 인이 가장 빠르고 후천 맹, 선천 맹의 순서로 나타났다. 2. 정안 인은 손목관절을 잘 이용하고 몸의 회전범위가 크며 서로 비슷한 동작 패턴을 보이고 있으나 선천 맹 은 전혀 그렇지 못했다. 3. 정안 인은 제2국면(P2)에서 허리가 어깨를 리드하며 공을 던지고 있으나, 선천 맹 과 후천 맹의 일부는 허리가 어깨를 리드하지 못했다. 4.정안 인들은 공이 날아 갈 방향을 쳐다보며 공을 던지나, 시각장애인들은 공이 날아 갈 방향을 쳐다보지 못했다. 5. 정안 인이 비교적 비슷한 패턴을 보이며 던지는데 비해, 후천 맹은 정안 인과 일부 비슷한 패턴을 보이고 있고, 선천 맹 은 각기 전혀 다른 패턴을 보이고 있다. 6. 정안 인의 체중이동이 잘되고 있는데 비해, 후천 맹 은 정안 인보다 좋지 못하고 선천 맹은 체중이동이 안 되고 있다. 이상을 종합해 보면 실명 시기가 던지기 동작에 많은 영향을 미친 다는 것을 알 수 있다.

• 대한정형외과스포츠의학회:학술대회논문집
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• 대한정형외과스포츠의학회 2003년도 제14차 학술대회
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• pp.120-131
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• 2003