• 제목/요약/키워드: Kinematical

검색결과 219건 처리시간 0.022초

플라잉디스크 포핸드 및 백핸드 던지기 동작의 운동학적 특성 비교 (A comparative analysis of the kinematical characteristics of Forehand & Backhand Flying Disc Throwing)

  • 김미향;박종철;변경석
    • 디지털융복합연구
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    • 제17권12호
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    • pp.555-563
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    • 2019
  • 본 연구는 플라잉디스크의 포핸드와 백핸드 던지기 동작에 대한 정량적 기초자료를 제공하기 위해 수행하였으며 이를 위해 3차원 동작분석 기법을 활용하여 운동학적 변인을 산출하였다. 연구 변인을 종합하여 분석한 결과 플라잉디스크는 멀리 던지는 것뿐만 아니라 정확하게 던지는 것이 중요하므로 P2와 P3에서는 전방으로의 이동을 제어하고 관절의 회전 운동에 집중해야하는 것으로 나타났다. 또한 효율적인 회전 운동을 위해 골반에서 몸통으로 회전력 전이가 중요한 것으로 판단된다. 포핸드는 상지 관절의 움직임을 주로 활용하여 던지기 동작을 수행하는 반면 백핸드 던지기는 비교적 몸통 및 골반의 회전을 주로 활용하여 던지는 것으로 나타났다. 본 연구의 정량적 자료를 바탕으로 플라잉디스크 현장 교육을 위한 기초자료로 활용될 수 있기를 기대한다.

태권도 옆차기 동작의 운동학적 분석 (A Kinematical Analysis of Side Kick Motion in Taekwondo)

  • 박광동
    • 한국운동역학회지
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    • 제13권2호
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    • pp.49-63
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    • 2003
  • For this study, four male university Taekwondo players were randomly chosen, between the weight categories of 60Kg and 80Kg. Their side kicks (yeop chagi), which are part of foot techniques, were kinematically analyzed in terms of the time, angle, and angular velocity factors involved with the kicks through the three-dimensional imaging. The results of the analysis are as fellows. 1. Time factor The first phase(preparation) was 0.48sec on average, accounting for 60% of the entire time spent; the second phase(the minimum angle of the knee joint) was 0.21sec on average, taking up 26% of the whole time spent; and the third phase(hitting) was 0.11sec on average, representing 14% of the entire time spent. 2. Angle factor In the first phase(preparation), rotating their bodies along the long axis, the players bended their hip and knee joints a lot, by moving fast in the vertical and horizontal directions, in the second phase(the minimum angle of the knee joint), the players continued to extend their bodies along the vertical axis, while pronating their lower legs and bending their hip and knee joints a lot to reduce the radius of gyration, and in the third phase(hitting), they extended their knee joints greatly so that the angle movements of their lower bodies shifted to circle movements. 3. Angular velocity factor In the first phase(preparation), the angular velocity of the hip and knee joints increased. while moving horizontally and rotating the body along the long axis; in the second phase(the minimum angle of the knee joint), the angular velocity increased by bending the hip and knee joints fast to reduce the rotation radios; and in the third phase(hitting), the angular velocity was found to have increased, by rotating the body along the long axis to increase the angular velocity and shifting the angular momentum of the pronated knee joint to the circular momentum.

인라인 스케이트 활주속력에 따른 T-Stop의 운동학적 분석 (Kinematic Analysis of T-Stop Motion by Inline Skate Rolling Speed)

  • 한제희;우병훈;김정구;김태완;김성섭;김의환
    • 한국운동역학회지
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    • 제20권4호
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    • pp.355-364
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    • 2010
  • The purpose of this study was to investigate the kinematical analysis of T-stop motion by inline skate rolling speed. Six subjects were participated in the experiment(age: $35.0{\pm}3.3$ yrs, weight: $72.70{\pm}5.1\;kg$, height: $176.30{\pm}3.1\;cm$, career: $10.00{\pm}2.5$ yrs). The study method adopted 3-dimensional analysis and 2 cameras for filming to analyze the required displacement of center of mass, displacement of right and left hip joint, displacement of right and left knee joint, displacement of trunk tilt using by APAS. The results were as follows; In anterior-posterior displacement of COM, the faster rolling speed, the longer displacement at phase 2. In vertical displacement of COM, the faster rolling speed, the lower displacement. In medial-lateral displacement of COM, there was no significant on rolling speed. In angular displacement of right thigh segment, the faster rolling speed, the bigger displacement in X and Z axis. In angular displacement of left thigh segment, the faster rolling speed, the lower displacement in X axis. In angular displacement of right shank segment, the faster rolling speed, the bigger displacement in Z axis. In angular displacement of left shank segment, the faster rolling speed, the bigger displacement in X and Y axis. In angular displacement of trunk segment, the faster rolling speed, the bigger displacement in Z axis.

Crouching Start 시 스타팅 블록 유형에 따른 운동학적 분석 (A Kinematical Comparative Study on Crouching Starts According to the Position Blocks in Race)

  • 최수남;오정환
    • 한국운동역학회지
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    • 제18권3호
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    • pp.93-105
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    • 2008
  • 본 연구는 스타팅 블록 유형에 따른 운동학적 변인을 분석하기 위하여 남자 단거리 선수 8명을 대상으로 스타팅 블록간의 거리를 세 가지(25cm, 40cm, 35cm)유형으로 구분하여 분석하였다. 본 연구에 참여한 평균 신장 180cm의 선수들에게는 출발선과 앞 블록의 거리 45cm, 블록간의 거리 40cm의 출발 유형이 100m 기록 단축을 위해서 유리한 스타팅 블록의 유형이라 할 수 있다. 이상의 결론을 종합해보면 100m 출발은 정지 상태에서 짧은 시간에 가능한 큰 추진력을 얻는 데 있으며, 중요한 기술적 요점은 출발 신호에 재빠르게 반응하고, 강한 킥에 의해 큰 추진력을 얻어 전경각과 중력을 잘 이용하여 빠른 시간 내에 최고의 속도에 도달하는데 있다. 본 연구에서는 B유형의 출발법이 기록 향상을 위해 효과적인 분석 결과를 보여주고 있다.

Kinematical Aspects Gliding Technique in 500-m Speed Skaters: From Start to Seven Strokes

  • Ryu, Jae Kyun;Kim, Young Suk;Hong, Sung Hong
    • 한국운동역학회지
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    • 제26권4호
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    • pp.333-341
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    • 2016
  • Objective: The purpose of this study was to assess the consistency of the gliding and push-off motion for single leg skating from the first to fourteenth steps. We hypothesized that: 1) there would be no difference in stroke trajectory, step rate, and cycle rate between the left and right steps of gliding; and 2) there would be a difference in the resultant velocity of toe push-off and the horizontal velocity of the center of mass after six step push-offs. Method: The study included five male 500-m speed skaters (mean height, $1.80{\pm}0.02m$; mean weight, $76.8{\pm}3.96kg$; record, $35.83{\pm}0.30sec$; 100-m record, <9.97 sec). Data were collected from the first to fourteenth steps (40 m) and recorded using five digital JVC GR-HD1KR video cameras (Victor Co., Japan) operating at a sampling frequency of 60 fields/sec and shutter speed of 1/500 sec. For each film frame, the joint positions were digitized using the KWON3D motion analyzer. Position data were filtered with low-pass Butterworth $4^{th}$ order at the cut-off frequency of 7.4 Hz. Results: The right toe of the skating trajectories at $2^{nd}$, $5^{th}$, and $7^{th}$ strokes differed from those of the left toe. The angles of the right and left knee demonstrated unbalanced patterns from the flexion and extension legs. The step and cycle rates of the right and left leg differed from the start until 20 m. The resultant velocities of the toe at the push-off phase and of the body mass center diverged before the six push-offs. Conclusion: This study's findings indicate that the toe of skating trajectory on left and right sliding after push-off should maintain a symmetrical trajectory. The resultant velocity of toe push-off and horizontal velocity from the center of body need to be separated after about six step push-offs.

국내 철봉 선수들의 Kovacs의 흔들기 및 체공 동작에 대한 평가 (The Evaluation of the Swing and Aerial Motion of Kovacs on Horizontal Bar)

  • Lim, Kyu-Chan
    • 한국운동역학회지
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    • 제30권4호
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    • pp.293-299
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    • 2020
  • Objective: The aim of this study was to investigate the swing and aerial motion of Kovacs, and evaluate the skill level of Kovacs by Korean adult players on horizontal bar. Method: The subjects for this study were 6 male top athletes participated in the 46th National Gymnastics against Cities and Provinces. After the motions of Kovacs were filmed by digital highspeed camcorder setting in 90 frames/s, kinematical data were calculated through DLT method. The variables were computed in the lapse time, the joint angle, the position·velocity of body COG, the inferred tension force of bar, and body COG path were simulated according to skill level of Kovacs. Results: Firstly, it was revealed that the lapse time was 1.19±0.03 s in the swing phase, and 0.83±0.03 s in the aerial phase. Secondly, it was revealed that the shoulder·hip joint motions of S1 and S2 were better than the other subjects in the swing phase, and the knee joint motions of S1 and S2 were better than the other subjects in the aerial phase. Thirdly, it was revealed that the horizontal·vertical velocity of body COG were -1.40±0.03 m/s, 3.80±0.07 m/s respectively, and the vertical positions of S1 and S2 were higher a little than the other subjects. Lastly, the skill level of Kovacs of this subjects was evaluated into 3 steps; excellent, advanced, normal. They need to train the swing motion including a giant circle, and body motions in the air. Conclusion: It would be suggested that Korean domestic players should improve to increase the vertical velocity at release instant and train to control the limbs elaborately in the air.

Testing delayed AGN feedback using star formation rate measurements by SED fitting with JCMT/SCUBA-2 data

  • Kim, Changseok;Jadhav, Yashashree;Woo, Jong-Hak;Chung, Aeree;Baek, Junhyun;Lee, Jeong Ae;Shin, Jaejin;Hwang, Ho Seong;Luo, Rongxin;Son, Donghoon;Kim, Hyungi;Woo, Hyuk
    • 천문학회보
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    • 제46권2호
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    • pp.40.2-40.2
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    • 2021
  • The impact of AGN on star formation is one of the main questions in AGN-galaxy coevolution studies. However, direct evidence of AGN feedback is still rare. One of the main obstacles is that various star formation rate (SFR) indicators are contaminated by AGN contribution. We present IR-based SFR measurements of a sample of 52 local (z<0.3) AGNs, which were selected based on kinematical properties of ionized gas outflows, using SED analysis with JCMT/SCUBA-2 data. First, we will compare IR-based SFR with other SFR indicators to check the reliability of the SFR indicators. Second, we will discuss the contribution of Mid-IR emission from hot dust of AGN torus by comparing SED fitting results with and without including AGN dust component. Finally, we will report the correlation between specific SFR (sSFR) and AGN activity (e.g., outflow strength or Eddington ratio) as evidence of no instantaneous feedback and discuss the implications of these results

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창던지기 동작의 kinematic적 특성분석 (Kinematical Analysis of Woman Javelin Throwing)

  • 이종훈
    • 한국운동역학회지
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    • 제12권2호
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    • pp.345-359
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    • 2002
  • 투창동작시 투창의 투사속도, 투사높이, 투사각도, 공기의 저항 등은 창의 수평거리와 궤적 등에 영향을 미치는 주요 요인으로, 본 연구에서는 투창의 던지기 동작시 선수들의 움직임을 정량적으로 분석하여 선수지도에 기초자료를 제공하고자 하는데 그 목적을 두었다. 이를 위해 제65회 전국육상경기 선수권대회 및 2002년 아시아게임 선발전경기의 상위 입상자 3명을 대상으로 힘발이 지면에 착지하는 순간부터 지지발이 지면에 착지하는 순간과 창이 손으로부터 릴리즈 되는 순간까지를 3차원 분석을 통하여 운동학적 변인을 분석하여 다음과 같은 결론을 얻었다. 선수들은 창을 뒤로 젖히고 크로스 스텝하는 동안 수평속도가 떨어지지 않도록 해야 할 것으로 사료되며, 릴리즈시 투사요인의 투사높이는 평균 $84{\pm}3.3%$, 투사각도는 평균 $38.7{\pm}1.9$도를 투사속도는 $15.6{\pm}3.4m/s$를 나타내었으며, 우수한 기록을 보인 S2는 투사높이는 가장 크게 나타났으나, 투사속도는 다른 선수에 비해 작은 것으로 나타났다. 또한 릴리즈시의 전경각에서 S2는 85도로 적절한 자세를 취하고 있으나, S1은 72.4도로 너무 자세를 낮추어 창의 릴리즈 속도 증가를 방해하는 것으로 사료되며, 투사순간의 신체분절속도에서 S2의 경우 타선수에 비해 신체중심과 상완, 전완의 속도가 빠르게 나타났으나, S1과 S3는 투사속도와 직접관련이 있는 전완의 속도를 좀더 증가시켜야 할 것으로 사료되며, 동작 수행시간에서 S2는 0.30초로 다른 선수에 비해 소요시간이 가장 빠르게 나타나 있고, 전체적으로 투사구간의 소요시간이 짧을수록 투사거리가 증가하는 것으로 나타났다. S1과 S3는 투사시간을 단축하여야 할 것으로 사료된다. 이상의 결론에 의하면, 앞으로 투창 동작시 선수 및 지도자들은 크로스 오버하여 지지발을 축으로 하여 투창이 투사될 때까지 적절한 상체각도, 고관절각도, 무릎각도 유지 및 투사시 창의 투사각도와 투사높이, 투사속도를 적절히 조절하는데 초점을 두어야 할 것으로 사료된다.

평행봉 Belle 기술동작의 운동학적 분석 (A Kinematical Analysis of Belle Motion on Parallel Bars)

  • 공태웅
    • 한국운동역학회지
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    • 제15권4호
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    • pp.43-53
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    • 2005
  • This study is to define how the difference of athletic change influence on the last regrasp after somersault in Belle movement of parallel bars. For his study, the following conclusion was produced by analysis of athletic change by means of three dimensional visual image in three athlete of nation. 1. As the picture of S1, there are total used time(2.01 sec), S3(2.17 sec) and S2(2.19 sec). In case of a short needed time, it is difficult for them to perform the remaining movement of the vertical elevating flight easily and comfortably, it is judged as performing the small movement with restrict swing. 2 In the change of body center sped by each event, it is calculated as $-89.1^{\circ}$ the narrowest in S1, $-81.96^{\circ}$ the widest and then $86.34^{\circ}$ in S3. In E3 event, average compound speed is 4.07m/s, S2 showed the fastest speed of 4.14m/s whereas S1 the narrowest angle of 3.95m/s. 3. A shoulder joint and coxa are the period of mention in E3. In E4 which was pointed out the longest vertical distance, S2 that is indicated the highest vertical height as the period of detach in parallel bars. showed -3.91m. This is regarded as a preparatory movement for dynamic performance after using effectively elastic movement of shoulder joint and coxa while easily going up with turning back movement. In the 5th phrase, long airborne time and vertical change position is showed as the start while regrasping securely air flight movement from high position. 4. In E5, a long flight time and a long vertical displacement were shown as the regrasp after somersault efficiently in high position with stability from the point of the highest peak of the center of the body. Especially, S2 is marked as a little bit long position, while S1 is reversely indicated as performing somersault and unstable motion in a low position. 5. In E3, at the point of the largest extension of the shoulder joint and hip joint the shoulder joint is largely marked in $182^{\circ}$ and the hip point $182^{\circ}$ in S2. The shoulder joint is marked at the smallest angle in $177^{\circ}$ and the hip point $176^{\circ}$ in S1. And S1 is being judged by its performance of the less self - confident motion with lessening a breath of swing. S2 makes the most use of flexion and extension of the shoulder joint and the hip joint effectively. It was performed greatly with swinging and dropping the rotary movement and the rotary inertia naturally. 6. In E6, as the point of regrasp of the upper arm in parallel bars it is recognized by the that of components of vertical and horizontal velocity stably. During this study, the insufficient thing and the study on the parallel bars at a real game later are more activated than now. If it is really used as the basic materials by means of Belle Picked Study of Super E level after Bell movement, you may perceive the technique movement previously and perform without difficulty. Especially, such technique as crucifix is quite advantageous for oriental people thanks to small body shape condition. In conclusion we will nicely prepare for our suitable environment to gradually lessen trials and errors by analyzing and studying kinematically this movement.

우수 골퍼의 아이언 클럽 스윙동작에 대한 운동학적 분석 (Kinematical Analysis of Swing Motion with Golf Iron Clubs Used by Elite Golfers)

  • 김갑선
    • 한국운동역학회지
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    • 제18권2호
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    • pp.85-94
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    • 2008
  • 본 연구의 목적은 3명의 우수 골프선수를 대상으로 아이언 클럽(3, 6, 9번)의 스윙 동작을 3차원적으로 비교 분석하고, 이의 분석에 따른 요인들을 정량적으로 제시하여 선수 및 일반 골퍼들이 바람직한 아이언 스윙 동작을 배우는데 기초자료를 제공하는데 있다. 3차원 영상분석을 실시하여 다음과 같은 결론을 도출하였다. 1. 각 클럽별로 전체 스윙 시간에는 큰 차이를 보이지 않았으며, 각 국면별 시간도 거의 유사하게 나타났다. 2. 각 클럽별로 어드레스와 임팩트시 머리위치 변화는 차이가 없었다. 3. 클럽의 길이에 따른 차이를 제외하면 각 클럽별로 오른 무릎관절 각도변화는 유사하게 나타났다. 4. 각 클럽별로 고관절의 회전각도 변화는 약간의 차이가 나타났다. 5. 각 클럽별로 어드레스와 임팩트 동작시 어깨관절의 회전각도와 동일하게 만들어 주어 스윙의 정확도를 높이고, 탑스윙시 어깨회전 각도를 $90^{\circ}$이상 유지하여 스윙의 회전력을 높이는 것으로 나타났다. 6. 클럽이 짧을수록 상체전경 각도가 약간의 차이로 커지는 것으로 나타났으며 어드레스와 탑스윙, 임팩트 동작시상체전경 각도가 $30-36^{\circ}$의 형태를 유지하면서 스윙을 하였다.