• 대한기계학회논문집 C: 기술과 교육
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• 제1권2호
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• pp.193-198
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• 2013

승마 시뮬레이터는 승마동작을 모사하여 실내에서 신체활동을 수행하기 위한 운동기구이다. 본 연구는 승마 시뮬레이터를 이용한 운동 시 소모되는 에너지 추정에 관한 연구이다. 실험은 총 9개의 동작으로 구분된 승마 동작에 대해 운동부하를 1분 단위로 변화시켜 총 25분 동안 운동을 수행하도록 설계하였으며, 호흡가스측정을 통해 에너지소모량을 수집하였다. 그 결과 신체조건에 따라 각 동작별 에너지소모량에 유의한 차이가 있음을 확인하였다. 이를 통해 사용자의 생체정보 측정 없이 신체정보만을 활용한 승마운동의 에너지소모량 추정방법을 개발하였다. 연구결과는 승마 시뮬레이터를 이용한 운동시 동작의 변화와 주행시간, 성별, 연령을 이용하여 실시간 에너지소모량의 계산이 가능해질 것이다.

• 한국운동역학회지
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• 제13권1호
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• pp.73-94
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• 2003

The purpose of this investigation was to analyze A kinematic analysis of the Kuzushi-arm motion when performing Morote-Seoinage in judo who was 5 females university representative judokas of light weight category in judo, and filmed on video cameras(60field/s). The data of this study digitizied by KWON3D 2.1 program computed the average and standard deviation calculated individual 5 trials with Programing Lab view 6i. From the data analysis & discussion, the following conclusions were drawn : 1) distance variable of attacking hand arm in kuzushi motion Left right(X direction) displacement variable was all of A, B, C pattern with moving left to right and leaning. Strip of displacement variable was ordo. to C(55.6cm), A(53.3cm), B(43.9cm) pattern, C pattern largely leaned to left Front Rear(Y direction) displacement variable was different A($131.3cm{\pm}3.1cm$), B($128.7{\pm}4.0cm$) and C(111.0cm) on ready position, 3 pattern leaned to rear direction. Strip of displacement was order to B(43.4cm), A(41.1cm) and C pattern(28.3cm). Up down(Z direction) displacement variable was all of A, B, C pattern leaned to up in the Kuzushi-phase and leaned to down in the Kake-phase. Strip of displacement was order to A(83.9cm), B(80.4cm), C pattern(71.9cm). 2) Shoulder joint angle variable Flexion and extension Ready position' angle was A($138.3{\pm}4.9^{\circ}$), B($142.9{\pm}3.7^{\circ}$) and C($164.5^{\circ}$) pattern, strip of flexion extension was order to C($80.9^{\circ}$), A($79.9^{\circ}$) and B($39.0^{\circ}$) pattern, greatly C pattern had largely angle change. Adduction and abduction : B and C pattern's angle change were adduction and abduction in the Kuzushi-phase after adduction in the Kake phase, A pattern's angle change was abduction in the Kuzushi-phase after adduction in the Kake phase. internal and external rotation : 3 pattern were internal rotation in the Tsukuri phase and external rotation in the Kake phase. After B and C pattern were external rotation and A pattern was internal rotation. 3) Elbow joint angle variable Flexion and extension 3 pattern's ready position angle were A($142.0{\pm}4.4^{\circ}$), B($123.5{\pm}5.5^{\circ}$) and C($105.5^{\circ}$) and flexion. Strip of flexion extension were order to A($57.9^{\circ}$), C($34.6^{\circ}$) and B($25.2^{\circ}$) pattern.

• 한국운동역학회지
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• 제13권3호
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• pp.81-98
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• 2003

The purpose of this study is to closely examine kinematic characteristics by jump phase of Li Xiaopeng motion in horse vaulting and provide the training data. In doing so, as a result of analyzing kinematic variables through 3-dimensional cinematographic using the high-speed video camera to Li Xiaopeng motion first performed at the men's vault competition at the 14th Busan Asian Games, the following conclusion was obtained. 1. It was indicated that at the post-flight, the increase of flight time and height and twisting rotational velocity has a decisive effect on the increase of twist displacement. And Li Xiaopeng motion showed longer flight time and higher flight height than Ropez motion with the same twist displacement of entire movement. Also the rotational displacement of the trunk at peak of COG was much short of $360^{\circ}$(one rotation) but twist displacement showed $606^{\circ}$. Likewise, Li Xiaopeng motion was indicated to concentrate on twist movement in the early flight. 2. It was indicated that at the landing, Li Xiaopeng motion gets the hip to move back, the trunk to stand up and the horizontal velocity of COG to slow down. This is thought to be the performance of sufficient landing, resulting from large security of rotational displacement of airborne and twist displacement. 3. It was indicated that at the board contact, Li Xiaopeng motion made a rapid rotation uprighting the trunk to recover slowing velocity caused by jumping with the horse in the back, and has already twisted the trunk nearly close to $40^{\circ}$ at board contact. Under the premise that elasticity is generated without the change of the feet contacting the board, it will give an aid to the rotation and twist of pre-flight. Thus, in the round-oH phase, the tap of waist according to the fraction and extension of hip joint and arm push is thought to be very important. 4. It was indicated that at the pre-flight, Li Xiaopeng motion showed bigger movement than the techniques of precedented studies rushing to the horse, and overcomes the concern of relatively low power of jump through the rapid rotation of the trunk. Li Xiaopeng motion secured much twist distance, increased rotational distance with the trunk bent forward, resulting in the effect of rushing to the horse. 5. At horse contact, Li Xiaopeng motion makes a short-time contact, and maintains horse take-off angle close to vertical, contributing to the increase of post-flight time and height. This is thought to be resulted from rapid move toward movement direction along with the rotational velocity of trunk rapidly earned prior to horse contact, and little shave of rotation axis according to twist motion because of effective twist in the same direction.

• 대한기계학회논문집A
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• 제24권4호
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• pp.848-857
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• 2000

A pick-and-place operation in 3-dimensional environment is basic operation for human and multi-purpose manipulators. However, there may be a difficult problem for such manipulators. Especially, if the object cannot be moved with a single grasp, regrasping, which can be a time-consuming process, should be carried out. Regrasping, given initial and final pose of the target object, is a construction of sequential transition of object poses that are compatible with two poses in the point of grasp configuration. This paper presents a novel approach for solving regrasp problem. The approach consists of a preprocessing and a planning stage. Preprocessing, which is done only once for a given robot, generates a look-up table which has information of kinematically feasible task space of end-effector through all the workspace. Then, using the table planning automatically determines possible intermediate location, pose and regrasp sequence leading from the pick-up to put-down grasp. Experiments show that the presented is complete in the total workspace. The regrasp planner was combined with existing path.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제35회 추계학술대회논문집
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• pp.672-675
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• 2010

본 연구에서는 저주파영역의 가진분무에 대하여 추가적인 내부가진을 수행함으로써 변조분사되는 분무특성에 대한 연구를 수행하였다. 회전식 가진장치를 사용하여 1차 가진을 생성한 후 2차 가진원인 마그네틱 밸브를 사용하여 변조하였다. 변조분무의 FFT결과와 분무패턴의 가시화를 통하여 관찰한 결과, 2차 가진 제어가 있는 변조분사의 경우 1차 가진만 있는 분사보다 분무의 상하 운동 진폭이 작으며 분무 하단류의 침투깊이가 증가하는 경향성이 발견되었다.

• 로봇학회논문지
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• 제14권1호
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• pp.50-57
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• 2019

This work presents a design and control method for a flexible robot arm operated by a wire drive that follows human gestures. When moving the robot arm to a desired position, the necessary wire moving length is calculated and the motors are rotated accordingly to the length. A robotic arm is composed of a total of two module-formed mechanism similar to real human motion. Two wires are used as a closed loop in one module, and universal joints are attached to each disk to create up, down, left, and right movements. In order to control the motor, the anti-windup PID was applied to limit the sudden change usually caused by accumulated error in the integral control term. In addition, master/slave communication protocol and operation program for linking 6 motors to MYO sensor and IMU sensor output were developed at the same time. This makes it possible to receive the image information of the camera attached to the robot arm and simultaneously send the control command to the robot at high speed.

• 한국운동역학회지
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• 제21권1호
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• pp.39-46
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• 2011

The purpose of this study was to examine differences between players who bend the left elbow and those who stretch it during the forward swing from BST to BC in a 2-handed backhand stroke among outstanding high school tennis players, and to assess the detailed 3D rotational kinematic characteristics of the shoulder and the hip. Statistically significant differences were observed between groups in the longitudinal axis rotation angle of the shoulder and the angle between the shoulder and the arm at BST, and in the side to side movement of the shoulder, the up and down movement of the hip, the side tilt angular velocity of the shoulder, the side tilt angular velocity of the hip, and the front tilt angular velocity of the hip at BC. The difference in the longitudinal axis rotation angle of the shoulder between the 2 groups suggests a difference in the flexibility of the joint in the shoulder arm racquet system. The longitudinal axis rotation angular velocity of the shoulder reached its peak at 75 % of the duration of the analyzed segment and then decreased little by little until BC. This time is considered the stage for increasing the angular velocity of the upper arm, the forearm, the hand and then the racquet, which are more distal segments than the shoulder.

• 한국운동역학회지
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• 제17권3호
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• pp.51-60
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• 2007

The purpose of this study was to kinematically analyze the differences between short(2.17 m) and long(10.94 m) putting stroke motions. Thirteen male professional golfers were participated in this study. Experiment was conducted on the artificial grass mat in the gymnasium. Kinematic data were collected by the 60 Hz Kwon3D motion analysis system. Differences were compared by SPSS paired t-test and one-way ANOVA. Duncan was used for post-hoc test and a=.05. The results were as follows: 1. Ground projected trajectory of the putter head were statistically straight during both short and long putts. 2. There was no consistent alignment tendency among shoulder, hip, and stance alignments. However stance alignment was consistent between short and long putts. Thus it is assumed that professional golfers align their body based on their stance alignment. 3. During putting, shoulder rotated not only up and down but also right and left. 4. Left and right elbow distance was maintained during all phases of the putts for both short and long putts. 5. Inter foot distance of long putting was longer than that of short putting.

• 대한정형도수물리치료학회지
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• 제26권2호
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• pp.19-27
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• 2020

Background: The purpose of this study was to examine the effects of a multi-modal exercise program for patients with chronic low back with respect to pain intensity, trunk muscle strength and Oswestry disability index. Methods: Thirty patients with chronic low back pain were recruited and divided equally into two groups. The multi-modal training program comprised a series of exercises such as warm-up, stabilization exercises, stretching, endurance exercises, and cool down whereas the control group performed only stabilization exercises. The both group spent an equal amount of time performing 60 minutes per day, three times per week, for five weeks. Results: The experimental group demonstrated statistically significant improvements in range of motion, trunk muscle strength, the visual analogue scale, and the Oswestry Disability Index (p<.05). Intergroup comparison showed a statistically significant difference in the range of motion of the lumbar spine and the degree of disability in the experimental group. Muscle strength and pain were statistically significant in both groups. Conclusion: The multi-modal exercise program is effective for patients with chronic low back pain, as it reduces lower back pain, increases trunk muscles strength, and decrease the potential for becoming disabled.

• 대한기계학회논문집B
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• 제24권9호
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• pp.1255-1263
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• 2000

In this study, the modification of turbulent boundary layer flow by local wall vibration is investigated. The wall is locally vibrated using a wall deformation actuator, which moves up and down at the frequencies of 100Hz and 50Hz. Simultaneous measurements of the streamwise velocities in the spanwise direction are performed at several wall-normal and streamwise locations using an in-house multi-channel hot wire anemometer and a spanwise hot-wire-probe rake. The mean velocity is reduced in most places due to the wall vibration and its reduced amount becomes small as flow goes downstream. Interestingly, the mean velocity is found to increase very near the wall and near the actuator. This is due to the motion induced by the streamwise vortices which are generated by the downward motion of the actuator. In case of the streamwise velocity fluctuations, their magnitude increases as compared to the unperturbed turbulent boundary layer, and the increased amount becomes small as the flow moves downstream. The modified flow field at the forcing frequency of 50Hz is not much different from that of 100Hz, except the reduced amount of modification.