미식축구의 필드골(Field Goal) 킥(Kick)에 대한 운동학적 분석

안찬규,김기형,최승방 한국운동역학회 2003 한국운동역학회지 Vol.13 No.1

Ahn, C-G · Kim , K-H · Chol, S-B. A three-dimensional kinematic analysis of the field goal kicking motion in American football. Korean Journal of Sport Biomechanics, Vol. 13,No. 1, pp. 139-153. The purpose of the study was to present technical guidance about the field goal motion of two skilled players and two unskilled players was corried out. The following conclusions were made: 1. In comparison on the total elapsed time of the kicking, there no significant differences between two groups. The progressing time from BP event to impact among experts group, however, took 0.141 second less than that of novices group. 2. The experts group showed right hip rotatier horizontally toward the targeted ball fixing left hip as the axis. On the other hand, the novices group didn't use the left hip as the axis in the kicking motion. 3. At the impact of kicking the ball, regarding with the distance of the ball and the supporting leg, the right and left distance of experts was 3.45cm longer than that of novices, the front and the rear distance of experts was 5.14cm shorter than novices. 4. At the impact, experts' initial velocity of the targeted ball was 5.27% faster than novices', besides experts' incidence angular displacement was 3.78˚ larger than novices'. 5. After BP event, experts showed a stable movement maintaining flexion and extension at left hip joint and knee joint. On the other hand, for novices, the angle of the left lower extremities became larger. 6. Experts showed the efficient flexion and extension of the hip joint and the knee joint during following procedure in the whole event of the kicking motion. At the BP event, the right knee joint angle of novices was 11.46˚ larger than that of experts. However, the duration of the impact event and FT event among, novices had less extension of knee joint than experts. 7. At the 2nd phase, for both of the groups, the angular velocity of the knee joint drastically increased as the angular velocity of hip joint decreased. However, only novices showed the largest negative angular velocity at the impact.

메타 물질 기법을 이용한 전방향성 복사 패턴을 갖는 평면형 S-DMB 안테나 설계 및 구현

안찬규(Chan Kyu An),유주봉(Ju Bong Yu),전준호(Jun Ho Jeon),김우찬(Woo Chan Kim),양운근(Woon Geun Yang),나병구(Byung Ku Nah),이재호(Jae Ho Lee) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.12

본 논문에서는 metamaterial CRLH(Composite Right- and Left-Handed) 구조 기반의 새로운 패치 안테나를 설계제작하여 측정하였다. 일반 마이크로스트립 패치 구조의 기본 공진 모드인 반파장 공진이나 반파장 공진의 양의 정수배와 달리 제안된 안테나는 구조 전체에 전계가 같은 위상을 갖게 한다. 본 논문에서 제안하는 안테나는 요구되는, λ/4 모노폴 안테나의 전형적인 특성인 전방향 패턴을 갖는 동시에 low-profile의 장점을 가진다. 제안된 안테나의 전산 모의 실험에는 Ansoft사의 FEM(Finite Element Method) 방식의 HFSS(High Frequency Structure Simulator)를 사용하였다. 제안된 안테나는 두께 1.6 ㎜, 유전율 4.4의 FR-4 기판을 사용하여 제작하였다. 구현된 안테나는 S-DMB(Satellite-Digital Multimedia Broadcasting) 서비스에서 사용되는 2.63~2.655 ㎓에서 VSWR(Voltage Standarding Wave Ratio)≤2임을 만족하며, 측정된 최대 이득과 효율은 각각 2.65 ㏈i와 81.14 %이다. In this paper, a novel patch antenna based on the metamaterial CRLH(Composite Right- and Left-Handed) structure is designed, implemented, and measured. Contrary to the standard microstrip patch's fundamental resonance mode of half-wavelength or its positive multiple, the proposed antenna shows the in-phase electric field over the entire antenna. The proposed antenna has a desired omni-directional field pattern which is typical characteristic of λ/4 monopole antenna, and also shows the merit of low profile. HFSS(High Frequency Structure Simulator) of Ansoft which is based on the FEM(Finite Element Method) is used to simulate the proposed antenna. FR-4 substrate of thickness 1.6 ㎜ and relative permitivity 4.4 is used for the proposed antenna implementation. The implemented antenna showed VSWR (Voltage Standarding Wave Ratio)≤2 for the frequency band from 2.63㎓ to 2.655 ㎓ which is used for S-DMB (Satellite-Digital Multimedia Broadcasting) service. And measured peak gain and efficiency are 2.65 ㏈i and 81.14 %, respectively.

클럽 샤프트(Club Shaft) 특성에 따른 골프 스윙(Golf Swing)동작 분석

김성일,김기형,김형수,이현섭,김진욱,안찬규,김희진 한국운동역학회 2002 한국운동역학회지 Vol.12 No.2

본 연구는 클럽 샤프트의 대표적인 재질인 그라파이트(graphite)의 유연한(flexible) 클럽 샤프트(club shaft)의 특성에 따라 피험자가 운동학적(kinematics) 요인이 되는 관절의 각변위, 각속도, 각가속도, 클럽헤드의 속도와 가속도와 같은 변인들이 어떻게 적응하는지 비교 분석하여 보다 효율적인 드라이버 선택에 도움을 주며 샤프트 특성에 따른 신체관절의 움직임에 대한 자료를 제시하고자 하였다. 고속 카메라 2대의 속도는 500fps로 하였고 각 regylar,stiff, x-stiff, 자신의 클럽을 포함 각 4개의 클럽을 사용하여 각 클럽당 3번씩 촬영하였으며 목표방향에서 20m이상 벗어나는 경우의 촬영은 다시 촬영하였다. 본 연구에서는 디지타이징(digitizing)을 신체 9개 마커는 강체로 가정된 클럽과 신체분절 모델로 정의하였으며 2 대의 카메라(500fps)로부터 얻은 avi화일을 컴퓨터에 저장하고 자료로부터 Butterworth 6th order recursive digital filter를 사용하여 1차 자료를 smoothing 하고 DLT를 이용하여 3차원 좌표를 구성하도록 한다. 좌표값을 얻기 위하여 kwon3d v3.0을 이용하였다. 본 실험은 피험자 스스로 클럽의 특성에 따라 스윙의 속도를 달리 하기 때문에 스윙의 시간이 달라지며 어느 정도 클럽이 강성에 따라 스윙시간이 빨라지는 결과로 나타났다. 이것은 피험자가 샤프트가 강성(stiffness)에 따라 스윙 속도를 빨리 하게 되는 원인이 되는 것으로 생각된다. 어깨의 각변위는 클럽이 regular의 경우 임팩트에서 각속도를 계속 유지하고 있으며 stiff, x-stiff의 경우에는 어깨의 움직임이 임팩트에서 급격하게 감소되는 것을 알 수 있다. 이것은 팔의 동작과 클럽의 힘을 크게 하기 위한 동작으로 생각된다. 어깨 각속도는 클럽이 stiff할수록 각속도가 큰 감속하는 것으로 나타났다. 손목속도는 regular 클럽의 경우 손목의 감속이 늦게 되고 임팩트에서 손목의 감속이 적게 하는 것으로 나타났으며 stiff와 x-stiff의 클럽에서 임팩트 시에 순간적인 감가속으로 인해 클럽의 속도를 증가시키고 있다. 임팩트 시에 손목의 감가속은 클럽헤드의 임팩트 시 속도를 증가시키는 결과를 보였다. 클럽헤드는 regular 클럽이 임팩트전에는 속도 증가가 커지는 결과와 일치된 결과를 보이고 있다. The purpose of this study was to find the rational method to analyze golf swing with specific property of club shaft. Three subjects were filmed by two high speed digital cameras with 500fps. The phase analyzed was downswing of each subject. The three-dimensional coordinates of the anatomical landmarks were obtained with motion analysis system Kwon3d 3.0 version and smoothed by lowpass digital filter with cutoff frequency 6Hz. From these data, kinematic and kinetic variables were calculated using Matlab(ver 5.0) The variables for this study were angular velocity and accelerations, which were calculated and following conclusions have been made : 1) Golf swing time of stiff club is faster than that of regular club. 2) In shoulder joint motion of swing with the stiff club, x-stiff showed mort rapid negative acceleration than that of regular club. 3) In regular club, the velocity of club head would be more effective velocity, which was increasing, than those of other clubs before impact. 4) In wrist joint motion of swing with stiff club, x-stiff club showed faster than regular club in the downswing and impact more rapid negative acceleration.

검도의 머리치기 동작에 관한 운동학적 분석

김기형(Ki Hyung Kim),김형수(Hyung Soo Kim),이현섭(Hyun Sub Lee),안찬규(Chan Gyu Ahn),윤완영(Wan Yung Yoon),김의환(Ui Hwan Kim) 한국사회체육학회 2001 한국사회체육학회지 Vol.16 No.-

The purpose of this study is to present descriptions of head hitting motion of Kumdo. In this study, We carried out kinematic analysis on head hitting motion of three Kumdo players for establishing the technique guidance to novice. After calculating angles of lower and upper extremities, angular velocities and angular accelerations, following results could be made. 1. The total elapsed time of head hitting motion was 0.67±0.12 seconds, the elapsed time of RP↔BS phase was 0.37±0.03 seconds and BS↔IP phase was 0.29±0.09 seconds. Therefore, the progressing time of RP↔BS phase took more than those of the other phase. 2. In RP phase, the angle of left elbow joint was 147.14±4.30, and left shoulder joint was flexion. In BS phase, the angle of left wrist joint was 81.10±5.74˚, that of left shoulder joint was 111.36±16.16˚. At the impact, the left wrist joint showed the highest extension. Furthermore, the angle of right trunk joint showed the highest flexion during BS phase. In the knee angle, it was 145.24±24.76˚ in BS phase and was 128.43±19.17° in IP phase. In the vertical displacement of the right foot, it was 13.8±2.75cm, which is the highest value in BS↔IP phase. so it was concluded that a effective stroke was by fast moving of a lower joint, flexion and extension in the upper joint. 3. In the angle velocity of the expert, it is occurred that the shoulder joint was 7.76±1.19 rad/s in BS phase, the elbow joint was 6.30±2.19 rad/s in BS↔IP phase and wrist joint was 18.15±0.46 rad/s in IP phase. Also, The knee joint angular velocity was -8.49±0.18 rad/s, which was the lowest velocity in BS phase and increased up to 4.28 ± 1.05 rad/s in IP phase. In the angular acceleration, it is occured that the left wrist joint was 365.21±114.31 rad/s^2, which was the highest angular acceleration in BS↔IP phase but was slow down in IP phase. At the impact, the left shoulder joint showed the highest angular acceleration.

CPW 급전 방식을 이용한 UWB 모노폴 안테나 설계 및 구현

유주봉(Ju Bong Yu),전준호(Jun Ho Jeon),안찬규(Chan Kyu An),김우찬(Woo Chan Kim),양운근(Woon Geun Yang) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.2

본 논문에서는 UWB(Ultra Wide Band) 통신 시스템에서 사용할 수 있는 CPW(Coplanar Waveguide) 급전 방식을 이용한 새로운 UWB 안테나를 설계 제작하여 측정하였다. CPW-fed 평면 슬롯 안테나는 광대역, 저비용과 무선 주파수 프론트 엔드 회로와 함께 간단히 집적화 시킬 수 있는 이점들을 가지고 있다. 제안된 안테나의 전산 모의실험에는 Ansoft사의 FEM(Finite Element Method) 방식의 HFSS(High Frequency Structure Simulator)를 사용하였다. 두께 1.6 ㎜, 유전율 4.4의 FR-4 기판을 사용하여 제작하였다. 제안된 안테나는 UWB 통신 시스템에서 사용되는 3.1~10.6 ㎓에서 VSWR(Voltage Standarding Wave Ratio)≤2임을 만족하였다. 측정된 최대 이득은 3 ㎓에서 2.61 ㏈i, 6 ㎓에서 4.95 ㏈i, 8 ㎓에서 2.89 ㏈i, 11 ㎓에서 7.35 ㏈i이다. In this paper, a novel CPW(Coplanar Waveguide)-fed UWB(Ultra Wide Band) antenna is designed, implemented, and measured for UWB communications. CPW-fed planar antenna has advantages of wide-bandwidth, low-cost and easy interaction with radio frequency front end circuitry. We have used HFSS(High Frequency Structure Simulator) of Ansoft which is based on the FEM(Finite Element Method) to simulate the proposed antenna. FR-4 substrate of thickness 1.6 ㎜ and relative permitivity 4.4 is used for implementation. The proposed antenna showed VSWR(Voltage Standarding Wave Ratio)≤2 for the frequency band from 3.1 ㎓ to 10.6 ㎓ which is used for ultra wide band communication. Measured peak gains are 2.61, 4.95, 2.89, 7.35 ㏈i at 3, 6, 8, 11 ㎓, respectively.

검도 초보자와 숙련자의 손목치기 동작의 좌측 상지관절에 대한 운동학적 분석

윤완영(Wan Yung Yoon),김성일(Seong Il Kim),안찬규(Chan Gyu Ahn) 한국사회체육학회 2001 한국사회체육학회지 Vol.16 No.-

The purpose of this study is to analysis and present descriptions of Wrist hitting motion of Gumdo. This study was carried out three dimentional kinematic analysis on wrist hitting motion of the two skilled and unskilled for instructing to novice. 1. There was no difference in AP or RFT during hitting wrist between the skilled and the unskilled, but the difference in the angle of the left wrist during impact between the skilled and the unskilled was significant(skilled; 152.64±1.32 and unskilled; 131.46±6.82). Therefore, it shows not only that the intensity and speed of hitting is better in the skilled than those in the unskilled but also the skilled reached at maximum angle of the left wrist while the unskilled didn`t. 2. Significant difference was not found in the algle of the left elbow at the event of AP, RFT and IP between the skilled and the unskilled(skilled; AP; 146.76±3.74, RFT; 114.66±2.31, IP; 163.11±5.62 and unskilled; AP; 137.97±0.70, RFT; 113.73±6.74, IP; 148.78±1.22). 3. There was difference in the angle of the left shoulder joint with the right foot taking off between the skilled and the unskilled(skilled; 123.67 ˚ and unskilled; 100.89 ˚). It shows that the skilled`s hitting was more efficient than that of the unskilled. 4. Significant difference was not found in the torque of the left wrist joint at the event of AP and RFT between the skilled and the unskilled. However, the torque of the left wrist joint was different significantly between the skilled and the unskilled(skilled; 31.06radian/sec and unskilled; 13.86 radian/sec). 5. In the IP, Despite of using the wrist joint, the unskilled was didn`t therefore, the unskilled was unefficient 6. There was difference in the torque of the left shoulder joint at the position of RFT between the skilled and the unskilled(skilled; -10,1±0.75 and unskilled;-6.57±6.29).