• 한국운동역학회지
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• 제18권1호
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• pp.1-10
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• 2008

본 연구는 축구 인스텝 킥에서 지지 다리의 후족각과 차는 다리의 해부학적 회전 운동의 자료들을 분석해서 다음과 같은 결론을 얻었다. 발목 관절에서의 외반각은 지지발의 접지 이전에 최대 피크에 도달했으며, 저측 굴곡은 그룹 간 최대 피크의 타이밍에서 약간의 차이가 나타났다. 지지발의 접지 시 후족의 굴곡각은 그룹 간 통계적으로 유의한 차이가 났으며, 지지발의 접지 시 하퇴의 운동은 그룹 간 유의한 차이가 없었다. 접지 이전에 이미 하퇴를 후방으로 많이 기울였으며, 임팩트 순간 하퇴의 좌우 기울기는 22도였다. 차는 다리 고관절의 굴곡/신전은 지지발의 접지 시 최대 피크에 이르렀으며, 이 순간 고관절의 최대 신전각은 30도 이상으로 나타났다. 차는 다리 무릎 관절의 굴곡각은 접지와 임팩트의 사이에 최대로 굽혔으며, 족관절의 최대 저측 굴곡각과 최대 외번각은 그룹 간 유의한 차이는 나지 않은 반면, 최대 외측 회전각은 유의한 차이가 났다.

• 한국운동역학회지
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• 제16권3호
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• pp.43-51
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• 2006

The purpose of this study was to analyze kinematic variables during turing back kick motion of Taekwondo. The subjects of this study were the 4 skilled and 4 unskilled of male university player in respectively. The experiment of this study was used two 16mm high speed cameras and its speed 125 frames/s. Analysis of this data was three dimensional cinematography using KWON3D program package. The results were as following; 1. In the elapsed time, there was no significance difference statically between a skilled and unskilled group. But skilled group was more fast during the motion of I phase. And unskilled group was more fast during the motion of II phase so called force production section, which had an influence on Diechagi's velocity. 2. In the center of gravity of human body, the changing of it was $1.10{\pm}0.04m$, $1.12{\pm}0.03m$ of LFM(left foot movement) and $1.36{\pm}0.08m$, $1.39{\pm}0.09m$ of RKF(right knee flection), and $1.44{\pm}0.08m$, $1.42{\pm}0.09m$ of RFI(right foot impact). There was no significance difference statically between the two groups. 3. The velocity of heel on impact was 1.13m/s in the skilled group and 1.23m/s in the unskilled group, when each angle of knee was $110.4{\pm}10.9deg/s$, $114.8{\pm}28.4deg/s$. The maximum velocity of each performance was reached before the RKF, and the velocity and angle at impact along by two groups did not show any significant difference statically. 4. In the angular velocity of just RKF of lower leg, there was significance difference statically between the two groups(p<.05).

• 항공우주기술
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• 제1권1호
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• pp.153-162
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• 2002

킥모터용 노즐목에 사용되는 공간적으로 보강된 탄소/ 탄소 복합재료의 기계적 물성치를 예측하고, 전체 노즐의 기계적 거동해석을 수행하였다. 이러한 3차원 등가물성치는 노즐의 기계적 거동해석에 필요한 3차원 물성치로 이용된다. 노즐목에 사용되어지는 공간적으로 보강된 복합재료는 그 구조에 따라서 물성치분포가 달라지므로 물성치 예측 프로그램을 개발하였다. 지금 개발되고 있는 킥모터용 노즐은 노즐목의 graphite 또는 공간적으로 보강된 탄소/ 탄소 복합재료, 노즐머리부분과 확장부의 carbon/ phenol, 그리고 확장부 외피의 강철로 구성되어있다. 추력에 가장 큰 영향을 미치는 노즐목의 변형형상은 4-D 탄소/ 탄소 복합 재료가 가장 균일하고, 작은 변형형상을 나타내었다. 이러한 해석 결과에 더하여 4D 탄소/ 탄소 복합재료 노즐목과 그라파이트 노즐목을 가진 모타 시험이 수행되었다.

• 한국운동역학회지
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• 제13권1호
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• pp.155-171
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• 2003

The purpose of this study was to analyze the kinematic variables of over head kick(OHK) in soccer with three dimensional analysis technique and show the kinematic characteristics of it. The 7 subjects were university football player who have been playing football more than 7 years. The OHK was filmed on 16mm video camera(30frame/sec.) kinematic variables were temporal, postures, and COG(center of gravity). The mean values and the standard deviation for each variables were obtained and used as basic factors for examining characteristics of OHK. The results of this analysis were as follows : Temporal variables : The total time elapsed(TE) of OHK was $0.95{\sim}1.14sec$, the 1st phase was 0.35sec., 2nd phase was 0.46sec., and 3rd phase was 0.22sec.. Posture variables : When subjects performed OHK at the impact event, the ankle and knee angle of kicking foot were more extend than supporting foot. but the hip angle of supporting foot were more extend than kirking foot. Moving distance of the center of mass of the both foot. When subject performed OHK at the impact event, the range of distance on mediolateral direction aspect into right left shoulder line, anteroposterior direction aspect was $20.9{\pm}10.5cm$, vertical direction aspect was $92.3{\pm}19.9cm$. Angular velocity : the faster angular velocity of knee ankle on the kicking foot pew form jump position to landing position, the faster velocity of ball became. C. O. G. variables. When subject performed OHK at the impact event, upper part of the body was getting lower, lower part of the body was getting higher.

• 한국지반환경공학회 논문집
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• 제24권1호
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• pp.51-60
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• 2023

수직 시추와 다르게 방향성 시추작업에서 발생하는 드릴스트링(drill string) 변형, 케이싱(casing) 마모, 키 씨팅(key seating) 등의 문제를 방지하기 위해서는 시추 궤도 내에서 발생하는 토크(torque)와 드래그(drag)가 최소화되어야 한다. 토크와 드래그의 크기는 시추 궤도 형태, 이수(mud), 드릴스트링의 종류 그리고 킥오프 지점(KOP, kick-off point)과 같은 매개변수들에 의해 결정되기 때문에 시추 궤도 설계 과정에서 고려하여 설계하여야 한다. 본 연구에서는 가장 일반적인 방향성 시추 궤도인 빌드-홀드(Build-hold) 형태의 시추 궤도에 킥오프 지점이 각기 다른 시추 궤도를 선정하였고, 분포하중 모델(analytical friction model)을 이용하여 각 구간내에서의 분포하중을 계산하여 궤도 전체에 대한 토크와 드래그를 계산하였다. 또한 매개변수에 따른 분석 값을 비교하여 분포하중이 최소로 발생하는 최적의 시추 궤도를 선정하였다. 분석결과 분포 하중을 최소화하기 위해서는 윤활성이 높은 이수를 사용, 궤도 형태에 따른 알맞은 킥오프 지점과 가능한 최소의 도그-래그를 지정하여 설계하는 것이 효과적임을 알 수 있었다. 이러한 결과는 분포하중을 최소화하기 위한 모든 방향성 시추 궤도 설계에 사용된다.

• 한국운동역학회지
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• 제23권4호
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• pp.285-294
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• 2013

The purpose of this study was to provide fundamental information for success factors of techniques through kinematic analysis including coordination of lower extremities and landing stability according to the success and failure of $540^{\circ}$ Dwihuryeochagi in Taekwondo. Twenty Taekwondo athletes: ten success group (S, age: $22.3{\pm}1.8$ yrs, height: $172.1{\pm}5.4$ cm, body mass: $64.4{\pm}4.2$ kg) and ten failure group (F, age: $22.3{\pm}1.8$ yrs, height: $172.1{\pm}5.4$ cm, body mass: $64.4{\pm}4.2$ kg) participated in this study. Three-dimensional motion analysis using a system of 3 video cameras with a sampling of 60 fields/s was performed during the competition of $540^{\circ}$ Dwihuryeochagi. Motions were divided into five events: pivot foot landing (E1), pivot foot toe off (E2), COM max height (E3), kick impact (E4) and landing (E5). At E1, the stride width was greater for S than for F (p<.05) while the time was greater for S than for F during P4 (p<.05). At E4, knee angle was greater for S than for F (p<.05). At E5, hip angle was greater for S than for F (p<.05) while kick distance was greater for S than for F (p<.05). Furthermore, at P3, the time would be related to kicking velocity (p<.05), while at P4, the time, range of hip angle and knee angle would be related to kick distance (p<.05). At P1, COM horizontal velocity would be related to COM vertical velocity of P1 and P2 (p<.05). Based on the findings, success factors of $540^{\circ}\acute{y}$ Dwihuryeochagi were COM horizontal velocity of P1, COM vertical velocity of P2, the time, kick distance, velocity, angle of lower extremities and coordination of P3-P4.

• 대한정형도수물리치료학회지
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• 제5권1호
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• pp.75-80
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• 1999

The Taekwondo being a martial sports, there are higher chances for the injury to occur than the non martial sports. Therefore, this study analyze the frequency, the area, the type, and the condition of the injury which are prone to occur in the Taekwondo matches; it is to help the Taekwondo players in prevention of the injury and in treatment. The subjects of this study were the 48 players (male 24, female 24) who participated in the final selection contest of the national team player on March 9 to 12, 1993. The data of the injury were obtained from the medical recoder staff and were analyzed to the frequency of the injury per match, the vulnerable area of the injury, the type of injury, and the condition of the injury with a gender difference. There were 24 matches for the male and 24 matches for the female, total 48 matches. Therefore, the total participation number of the players are the double of the match number. 1. The frequency of the injury per match was 18.3%(11/60) for male and 23.1%(12/52) for women. 2. The areas of the injury were ankle 36.4%(4), foot 18.2%(2), knee 18.2%(2), lower leg 18.2%(2), wrist 9.1%(1) in male; foot 33.4%(4), ankle 16.7%(2), knee 16.7%(2), lower back 16.7%(2), lower leg 8.3%(1), face 8.3%(1) in female. 3. The types of the injury were contusion 45.5%(5), sprain 27.3%(3), abrasion 9.1%(1), laceration 9.1%(1), tendon rupture 9.1%(1) in male; contusion 33.3%(4), sprain 33.3%(4), abrasion 16.7%(2), subcutaneous hemorrhage 8.3%(1), dislocation 8.3%(1) in female. 4. The condition of the injury were the unblocked attack 36.4%(4), attacking kick 27.3%(3), blocking a kick 18.2%(2), attacking punch 9.1%, impact with surface 9.1%(1) in male; attacking kick 33.3%(4), unblocked attack 25%(3), blocking a kick 25%(3), attacking punch 8.3%(1), impact with surface 8.3%(1) in female. This study shows that the injury from the Taekwondo matches occurred most in the lower extremity joints and the foot, and shows that the most of the injury types were contusion and sprain. Therefore, it is believed to be helpful to wear the proper fitting ankle or the knee protector and using other protective equipment to prevent the sports injury in the Taekwondo matches.

• 한국운동역학회지
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• 제17권2호
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• pp.131-143
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• 2007

In this study, we are concluded like this : 5 men who are soccer player of P university in B city measure the Electromyography with an angle of motion according to kinesiotaping's application when practicing in-step kick. When exercising in-step kick, the change of realization of muscle load of lower limbs enhence Gastrocnemius Lateralis and Vastus Medialis in the section of backswing, and improve Tibialis Anterior, Vastus Medialis, Rectus Femoris prior to impact after back-swing. Before impact, it mainly impoved Tibialis Anterior, Vastus Medialis, Rectus Femoris. After impact, it generally improved Gastrocnemius Lateralis, Vastus Medialis. Average integral electromyography value, it was such a small difference(; the difference of the value in Tibialis Anterior, Rectus Femoris, Vastus Medialis) that we can't compare case of after taping than before. In Electromyography, in case of after taping was considerably decreased at Gastrocnemius Lateralis, there was statistically significant difference between before and after. It was a little increased, after taping than before at Knee angle. And degree was a little decreased at Ankle angle. But, It's so delicate difference, there was not statistically significant difference between before and after.

• 항공우주기술
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• 제6권1호
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• pp.114-119
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• 2007

본 연구는 KSLV-I 페이로드 페어링을 제외한 2단 구조부에 대한 모드시험 결과를 기술하고 있다. 2단부는 크게 위성 분리부, 탑재부, 킥모터 지지부, 킥모터로 구성되어 있다. 번지코드를 이용하여 자유경계단 조건을 모사하였고 가진은 대형 가진 망치를 사용하였다. 이러한 모드시험 결과를 통하여 모드변수를 추출할 수 있고, 2단부 구조체의 동특성을 파악할 수 있다. 시험 결과는 TDAS를 사용하여 분석하였고, 100Hz 이하의 모드변수 및 모드형상을 추출하였다.

• 항공우주기술
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• 제11권2호
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• pp.117-121
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• 2012

고공 환경 하에서 작동하는 우주발사체 상단 추진기관의 경우 지상에서 실제 작동 환경에 가까운 조건에서 연소시험을 수행하여 그 성능을 검증하게 된다. KSLV-I 상단 추진기관의 경우 원통형 디퓨저를 이용하여 고공환경 모사시험을 수행하였으며, 디퓨저의 설계 검증 및 시동특성을 확인하기 위해 축소형 디퓨저에 대한 비반응 유동시험 및 연소시험을 수행하였다. 본 논문에서는 축소형과 실물형 디퓨저에 대한 시험 결과를 제시하고 시동특성에 대해 분석하였다.