• 로봇학회논문지
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• 제1권2호
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• pp.188-196
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• 2006

During the communication and interaction with a human using motions or gestures, a humanoid robot needs not only to look like a human but also to behave like a human to make sure the meanings of the motions or gestures. Among various human-like behaviors, arm motions of the humanoid robot are essential for the communication with people through motions. In this work, a mathematical representation for characterizing human arm motions is first proposed. The human arm motions are characterized by the elbow elevation angle which is determined using the position and orientation of human hands. That representation is mathematically obtained using an approximation tool, Response Surface Method (RSM). Then a method to generate human-like arm motions in real time using the proposed representation is presented. The proposed method was evaluated to generate human-like arm motions when the humanoid robot was asked to move its arms from a point to another point including the rotation of its hand. The example motion was performed using the KIST humanoid robot, MAHRU.

• PNF and Movement
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• 제12권3호
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• pp.173-179
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• 2014

Purpose: The purpose of this study is to analyze the effect of arm leg flexion patterns of proprioceptive neuromuscular facilitation on the muscle activation of the contralateral lower extremity. Methods: In this study, Electromyogram MP150(Biopac system, USA) was applied to 20 healthy male subjects. Unilateral arm flexion- abduction- external rotation pattern and Unilateral leg flexion- adduction- external rotation with knee flexion pattern were applied within mid range of the supine position for measurement. The muscle activation of vastus lateralis, biceps femoris, tibialis anterior and gastrocnemius(medialis) muscle of the contralateral lower extremity were compared and analyzed during the applications. Results: The results of this study were summarized as follows: There was a statistically significant difference in the muscle activation of vastus lateralis and biceps femoris between the arm and leg patterns(P<0.05). There was a statistically significant difference in the muscle activation of gastrocnemius and tibialis anterior between the arm and leg patterns(P<0.05). Conclusion: contralateral vastus lateralis, biceps femoris, gastrocnemius and tibialis anterior muscles show the higher muscle activation in the leg pattern than one in the arm pattern.

• Clinics in Shoulder and Elbow
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• 제3권2호
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• pp.95-101
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• 2000

Purpose : The purpose of this study was to evaluate the efficacy of oblique coronal MR images, oblique axial images of neutral, internal rotation and external rotation positions in the diagnosis of SLAP Ⅱ lesion. Materials and Methods: MR arthrography of the glenohumeral joint was evaluated retrospectively in 16 patients(16 shoulders) who underwent arthroscopic surgery(mean age; 38 years old, Male; 13, Female; 3). Oblique coronal fat-suppressed Tl-weighted spin echo images were performed with each shoulder in the neutral position of the arm and oblique axial images were performed in neutral, internal and external rotations of the arm respectively. The preoperative findings of MR were classified as definite tear, possible tear and no tear. Arthroscopic findings were correlated with MR findings of several different position of the arm. Results: Arthroscopic surgery revealed 8 SLAP Ⅱ lesion, 2 SLAP I lesion, and 6 normal superior labrum respectively. The accuracy of diagnosis in the 8 SLAP Ⅱ lesion were high on oblique axial image in external rotation which were interpreted as 8 definite tear, to compare with oblique axial images in neutral position which were interpreted as 4 definite tear, 3 possible tear, 1 no tear. The 6 normal superior labrum lesion were interpreted as no tear in all three position. The 2 SLAP I lesion were interpreted as 1 definite tear, 1 no tear on oblique axial image in neutral position and 1 definite tear, 1 possible tear on oblique axial image in external rotation. Conclusion: This study showed that axial MR images in external rotation of the arm combined with oblique coronal images have proved to be effective to detect SLAP Ⅱ lesion, and should be considered in imaging protocol for MR arthrography of the SLAP Ⅱ lesion.

• Clinics in Shoulder and Elbow
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• 제25권4호
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• pp.255-256
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• 2022

• 한국콘텐츠학회논문지
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• 제20권6호
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• pp.99-113
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• 2020

미래에는 일상생활에서 우리 삶을 편의를 위한 로봇이나 드론들이 증가할 것이다. 그리고 이것을 제어하기 위한 방법으로 현재 리모컨이나 사람의 음성에 의한 방법이 가장 보편적으로 사용되고 있다. 하지만 리모컨은 사람이 찾아서 일일이 조작해야하며 음성의 경우에는 주변 노이즈를 무시할 수 없다. 그래서 본 논문에서는 팔의 자세정보만으로 무선으로 간편하게 주변 드론이나 로봇들을 제어 할 수 있다는 전제하에 실시간으로 정확하게 팔의 자세정보를 획득하기 위한 경제적인 자세정보 획득방법에 대하여 연구하였다. 이를 위해서 확장 칼만필터를 이용하여 팔의 자세정보에 대한 노이즈를 제거하였으며 팔의 움직임을 감지하기 위하여 저가의 MEMS 타입의 센서를 적용하여 장치의 경제성을 확보하였으며 팔의 착용성을 증대시키기 위하여 FPGA를 활용하여 최대한 칩 하나에 모든 기능을 집적화시켜 소형 경량의 자세정보 획득장치를 개발하였다. 그 결과 1 ms의 실시간성을 확보하였고 확장칼만필터를 적용하여 노이즈가 제거된 정확한 팔의 자세정보를 획득하고 실시간으로 팔의 자세정보를 전시하였다. 이를 통해서 팔의 실시간 자세정보를 이용하여 명령을 생성할 수 있는 기초가 마련되었다.

• 전자공학회논문지 IE
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• 제43권4호
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• pp.28-36
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• 2006

본 연구에서는, 팔의 4가지 운동을 구별할 수 있는 계측 시스템과, 구별된 팔의 운동 위치를 추정할 수 있는 제어 알고리즘에 관하여 기술한다. 먼저 4가지(굽히기와 펴기, 내전과 외전) 운동을 구별하기 위해 굽혀진 정도를 측정할 수 있는 전기 저항 형태의 굽힘 센서를 사용한다. 이 센서를 왼팔의 상완 이두근과 오구완근에 1개씩 부착한다. 부착된 두 개의 센서로부터 출력되는 신호는 증폭기와 필터 등으로 구성된 계측 시스템을 통과한다. 이 시스템에서는 상완이두근에 부착된 센서 신호는 굽히기와 펴기 운동 중에서만 On/OFF 작동을 하도록 하고, 오구완근에 부착된 센서 신호는 모든 운동에 작동하도록 설계하였다. 이렇게 출력된 신호들로부터 4가지 운동은 구별하여 출력하고, 출력된 신호들로부터 팔의 운동 위치를 측정한다. 마지막으로, 제안된 알고리즘의 효용성을 입증하기 위해 RC 서보 모터와 포텐션미터로 구성된 2자유도의 인공팔을 제작하여 실험한다. 실험을 통해 인공 팔의 위치는 모터의 회전 관성, 센서의 노이즈 등으로 실제 팔의 위치와 차이가 발생하였다 이 오차를 감소하기 위해 오차값과 오차의 변화값에 근거한 퍼지 PID 제어기를 사용하였고, 이로써 오차가 5도 이내로 감소되었다.

• 한국전문물리치료학회지
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• 제8권1호
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• pp.76-88
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• 2001

Back extension exercises have been used for rehabilitation of the injured low back, prevention of injury, and fitness training programs. However, excessive loading on low back can exacerbate existing structural weakness. The purpose of this study was to compare muscle activity of low back muscles during back extension exercises. Twenty healthy male subject s were evaluated. Electromyographic (EMG) activities of low back muscles at L1 and L5 level were recorded during seven different back extension exercises and two reference tasks by surface EMG and saved for data analysis. Reference tasks of lifting 20% and 40% of their body weight were included for comparison. The result were as follows: 1) Single-arm extension and single-leg extension exercises on quadruped position appeared to constitute a low-risk exercise for initial extensor strengthening. 2) When arm extension was combined with contralateral leg extension on quadruped position, EMG activities of low back muscles were increased. 3) EMG activity of low back muscles was highest during the trunk extension exercises on prone position. 4) EMG activities of low back muscles during arm and leg extension exercises on quadruped position were less than those of reference task of lifting 40% of their body weight. These result s have important implications for progressive back extensor muscle strengthening exercises in patients with back pain.

• Journal of electromagnetic engineering and science
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• 제19권2호
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• pp.115-121
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• 2019

This paper presents the effects of the position of the split of a split-ring resonator (SRR) on the performance of a composite broadband printed dipole antenna. The antenna is made of two printed dipole arms enclosed by two rectangular and identically printed SRRs. One dipole arm and the SRR are printed on the top side of the substrate, while the other dipole arm and SRR are printed on the bottom side of the same substrate. By changing the position of the split on the SRR, different antenna characteristic values are obtained, namely, for impedance bandwidth and radiation patterns. The split position is thus a critical parameter in antenna design, because it influences the antenna's major performance immensely. Different split positions and their consequences for antenna performance are demonstrated and discussed. The antenna generates linearly polarized radiations, and it is computationally characterized for broadband characteristics. The optimized compact antenna has overall dimensions of 9.6 mm × 74.4 mm × 0.508 mm (0.06λ × 0.469λ × 0.0032λ at 1.895 GHz) with a measured fractional bandwidth of 60.31% (1.32 to 2.46 GHz for |S₁₁| <-10 dB) and a radiation efficiency of >88%.

• 한국운동역학회지
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• 제24권1호
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• pp.43-50
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• 2014

The purpose of this study was to analyze of the GRF (ground reaction force) parameters according to the change of positions and weights of bag during downward stairs between dominant and non-dominant in upper & lower limbs. To perform this study, participants were selected 9 healthy women (age: $21.40{\pm}0.94yrs$, height: $166.50{\pm}2.68cm$, body mass: $57.00{\pm}3.61kg$, BMI: $20.53{\pm}1.03kg/m^2$), divided into 2 carrying bag positions (dominant arm/R, non-dominant arm/L) and walked with 3 type of bag weights (0, 3, 5 kg) respectively. One force-plate was used to collect GRF (AMTI OR6-7) data at a sample rate of 1000 Hz. The variables analyzed were consisted of the medial-lateral GRF (Fx), anterior-posterior GRF (Fy), vertical GRF (Fz), impact loading rate and center of pressure (COPx, COPy, COP area, COPy posterior peak time) during downward stairs. 1) The Fx, Fy, Fz, COPx, and COP area of GRF were not statistically significant between dominant leg and non-dominant leg, but non-dominant leg, that is, showed the higher COPy, and showed higher impact loading rate than that dominant leg during downward stairs. 2) In bag wearing to non-dominant arm, Fx, Fz, COPx, COPy, impact loading rate and COP area showed increase tendency according to increase of bag weights. Also, against bag wearing to dominant arm, non-dominant showed different mechanism according to increase of bag weights. The Ground Reaction Force parameters showed different characteristics according to the positions and weights of bag during downward stairs between dominant and non-dominant arm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.799-804
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• 1991

This paper is concerned with the artificial control of prosthetic devices using the electromyographic(EMG) activities of biceps and triceps in human subject during isometric contraction adjustments at the elbow. And it was analysised about recognition of EMG signals and dynamic characteristics at arm movements of human. For this study the error signal of autoregressive(AR) model were used to discriminate arm movement patterns of human. Interaction of dynamic characteristics (Position, Velocity, Acceleration) and EMG of biceps and triceps at arm movements of human was measured.