• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.237-254
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• 2005

The vast mechanical systems could be classified as closed loop system, open loop system and open & closed (switching) system. In the closed loop system, the kinematics and dynamics of 3-D mechanisms will be reviewed and closed form solutions using the direction cosine matrix method and reflection transformation method will be introduced. In the open loop system, kinematic & dynamic analysis methods regarding the redundant system which has more degrees of freedom in joint space than those of task space are reviewed and discussed. Finally, switching system which changes its phase between closed and open loop motion is investigated with the principle of dynamical balance. Among switching systems, the human gait in biomechanics and humanoid in robotics are presented.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.119-122
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• 2009

본 연구는 뇌졸중으로 인한 편마비 환자 20명을 대상으로 총 8주간 시지각 운동 과제를 적용하여 자세 균형, 보행 양상에 미치는 효과를 검증하고자 시행하였다. 실험군(n=10)과 대조군(n=10) 모두 보존적인 물리치료를 실시하였고 실험군에는 시지각 운동 과제 프로그램을 더하여 실시하였다. 본 연구의 결과는 실험군의 되먹임 측정을 통한 자세 균형 검사에서 편평한 지면 위에서 눈을 뜨고 감은 상태의 안정성 지수는 유의한 감소를 보였으며, pillow 위에서 눈을 뜨고 감은 상태의 안정성 지수도 유의하게 감소하였다. 체중분포지수는 편평한 지면에서 눈을 뜨고, 감은 상태와 pillow 위에서 눈을 뜨고 감은 상태 모두에서 유의하게 감소하였다. 실험군에서 10m 보행 속도는 대조군과 달리 유의하게 증가하였다. 본 연구에서의 시지각적 운동과제 프로그램은 편마비 환자의 신체기능과 관련된 자세균형 및 보행을 증진시키는 효과가 있었고 이에 보다 효과적인 운동방법으로 제시할 수 있다.

• Journal of Information Processing Systems
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• 제15권4호
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• pp.785-796
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• 2019

Due to the view point, illumination, personal gait and other background situation, person re-identification across cameras has been a challenging task in video surveillance area. In order to address the problem, a novel method called Joint Bayesian across different cameras for person re-identification (JBR) is proposed. Motivated by the superior measurement ability of Joint Bayesian, a set of Joint Bayesian matrices is obtained by learning with different camera pairs. With the global Joint Bayesian matrix, the proposed method combines the characteristics of multi-camera shooting and person re-identification. Then this method can improve the calculation precision of the similarity between two individuals by learning the transition between two cameras. For investigating the proposed method, it is implemented on two compare large-scale re-ID datasets, the Market-1501 and DukeMTMC-reID. The RANK-1 accuracy significantly increases about 3% and 4%, and the maximum a posterior (MAP) improves about 1% and 4%, respectively.

• 한국운동역학회지
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• 제24권3호
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• pp.287-293
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• 2014

The purpose of this study was to investigate the effects of Hoehn-Yahr scale on the activation of lower-extremity muscles during walking. Electromyography (EMG) analysis was carried out on 36 patients with Parkinson's disease in the off phase of the medication cycle. We recorded EMG signals of the tibialis anterior (TA), medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), rectus femoris (RF), vastus lateralis (VL), semitendinosus (ST) and biceps femoris (BF) using Noraxon 16 channels EMG system during walking at preferred speed. Rectified EMG signals were normalized to reference voluntary contractions (RVC) over a gait cycle at the preferred speed, allowing for an assessment of how the activity was distributed over the gait cycle. Compared to the H & Y Scale 1, H & Y Scale 3 exhibited greater activation of the vastus lateralis during mid-stance and greater activation of the medial gastrocnemius during terminal swing. Compared to the H & Y Scale 1, H & Y Scale 2 and 3 exhibited less activation of the tibialis anterior during initial swing. We conclude that the more Hoen & Yahr Scale increase, the more abnormal lower-extremity muscles activation.

• 한국산학기술학회논문지
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• 제11권11호
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• pp.4374-4381
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• 2010

본 연구는 복합운동프로그램이 뇌졸중 환자의 상지 기능 및 균형 능력에 미치는 효과를 알아보는 것이었다. 연구 대상자는 뇌졸중으로 인한 좌측 편마비 증상을 보이는 68세 여성이며, 연구 기간은 2005년 4월 17일부터 2007년 8월 30일까지였다. 복합운동프로그램은 관절가동범위운동, 근력강화운동 및 반복적인 과제-지향적 활동 등으로 구성되었으며, 대상자는 주 3회, 매 회기 1시간씩 복합운동프로그램을 수행하였다. 대상자의 상지 기능은 브론스트롬 손회복 및 상지 회복 단계, Fugl-Meyer Assessment of Motor Function, 뇌졸중 상지기능검사로 측정하였고, 균형 능력은 Tinetti Gait & Balance Scale과 One Leg Standing Test로 평가하였다. 연구 결과 대상자의 상지 기능 검사의 점수가 향상되었고, 균형 능력 검사 점수는 유지 및 향상되는 것으로 나타나, 복합운동프로그램이 뇌졸중 환자의 상지 기능과 균형 능령을 증진시키는 것으로 나타났다.

• Physical Therapy Rehabilitation Science
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• 제9권4호
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• pp.318-323
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• 2020

Objective: Reacquisition of motor functions following stroke depends on interhemispheric neural connections. The intervention highlighted in the present case is an insight for augmenting motor recovery by stimulating the lesioned area and adjacent areas governing the motor behaviour of an individual. The purpose of this study was to determine the changes in the motor and cognitive outcomes through multi target stimulation of cortical areas by application of multichannel transcranial direct current stimulation (M-tDCS) in a stroke survivor. Design: A case report. Methods: The patient was a participant of a trial registered with the clinical trial registry of India (CTRI/2020/01/022998). The patient was intervened with M-tDCS over the left primary motor cortex i.e. C3 point and left dorsolateral prefrontal cortex i.e. F3 point with 0.5-2 mA intensity for the period of 20 minutes. SaeboFlex-assisted task-oriented training, functional electrical stimulation over the lower extremity (LE) to elicit dorsiflexion at the ankle and eversion of the foot, and conventional physiotherapy rehabilitation including a tailored exercise program were performed. Outcome assessment was done using the Fugl-Meyer assessment scale (FMA) for the upper and lower extremity (UE and LE), Montreal Cognitive Assessment (MOCA), Wisconsin Gait Scale (WGS) and the Stroke Specific Quality of Life (SSQOL) measures. Assessment was taken at Day 0, 15 and 30 post intervention. Results: Improvement was observed in all the outcome measures i.e FMA (UE and LE), MOCA, SSQOL and WGS across the span of 4 weeks. Conclusions: M-tDCS induced improvement in motor functions of the UE and LE, gait parameters and cognitive functions of the patient.

• 한국운동역학회지
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• 제31권4호
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• pp.259-269
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• 2021

Objective: The purpose of this systematic review and meta-analysis was to investigate age-related bimanual coordination functions in older adults. Method: Thirteen studies that compared bimanual coordination functions in older adults with those in healthy young adults qualified for this meta-analysis. We additionally categorized 21 total comparisons from the 13 qualified studies into two types of task-related moderator variables: (1) kinematic versus kinetic movements and (2) symmetry versus asymmetry movements. Results: Random effects model meta-analysis found that older adults revealed significant bimanual coordination impairments as compared with young adults (Hedges's g = -0.771; p < .0001; I² = 74.437%). We additionally confirmed specific bimanual coordination deficits using two moderator variables: 1) kinematic (Hedges's g = -0.884; p < .0001; I² = 0.000%) and kinetic (Hedges's g = -0.666; p = .023; I² = 86.170%). 2) symmetry (Hedges's g = -0.712; p = .001; I² = 74.291%) and asymmetry (Hedges's g = -0.817; p < .0001; I² = 76.322%). The moderator variable analysis indicated older adults indicated bimanual coordination deficits in the upper extremities than healthy young adults while performing kinematic bimanual coordination tasks and asymmetry coordination tasks. Conclusion: These findings suggest that developing motor rehabilitation programs based on asymmetric bimanual movement task for enhancing interlimb coordination functions of older adults may be crucial for increasing their independence in everyday activities. Given that elderly revealed the deficits in lower extremities coordination when older adults perform gait, posture, and balance, future studies should estimate lower limb coordination functions in elderly people.

• The Journal of Korean Physical Therapy
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• 제32권5호
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• pp.302-306
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• 2020

Purpose: The purpose of this study was to investigate comparisons of vastus medialis (VMO) and vastus lateralis (VL) muscle activities according to different heights during drop landing in flatfooted adults. Methods: Fifteen subjects with a flat foot arch and 15 subjects with a normal feet arch were participated. Subjects performed a double limb drop landing task from 20, 40, and 60 cm heights. Surface electromyography was used to measure the muscle activities of the VMO and VL during drop landing. Results: There were significant differences of muscle activities in the VMO, VL, and the VMO and VL ratio between groups. The electromyography values of VMO, VL, and the VMO and VL ratio in the normal group were significantly greater than in the flat foot group, and muscle activities and the VMO and VL ratio significantly increased with landing heights in the both groups. Conclusion: Our results indicated that muscle activity patterns of VOM and VL in the flat foot group were lower at heights than in the normal group, so calf tightness was negative effects on balance and gait ability, so assessment of muscle activation patterns in the knee extensors should be considered during exercise and treatment of flat feet.

• 제어로봇시스템학회논문지
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• 제10권4호
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• pp.350-356
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• 2004

This paper presents a farce manipulability analysis of multi-legged walking robots, which calculates force or acceleration workspace attainable from joint torque limits of each leg. Based on the observation that the kinematic structure of the multi-legged walking robots is basically the same as that of multiple cooperating robots, we derive the proposed method of analyzing the force manipulability of walking robot. The force acting on the object in multiple cooperating robot systems is taken as reaction force from ground to each robot foot in multi-legged walking robots, which is converted to the force of the body of walking robot by the nature of the reaction force. Note that each joint torque in multiple cooperating robot systems is transformed to the workspace of force or acceleration of the object manipulated by the robots in task space through the Jacobian matrix and grasp matrix. Assuming the torque limits are given in infinite norm-sense, the resultant dynamic manipulability is derived as a polytope. The validity of proposed method is verified by several examples, and the proposed method is believed to be useful for the optimal posture planning and gait planning of walking robots.

• 한국지능시스템학회논문지
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• 제21권1호
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• pp.132-137
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• 2011

4족 보행로봇은 보행 안정성이 높아서 향후 다양한 분야에 활용이 기대되며, 효율적인 보행을 위한 걸음새의 생성과 제어가 중요하다. 특히, 다양한 로봇 모델들에 대한 수요와 여러 가지 걸음 동작의 필요성으로 인하여 자동적인 걸음새 생성기법이 요구된다. 본 논문에서는 HyperNEAT(Hypercube-based NeuroEvolution of Augmenting Topologies)를 사용하여 지형변화에 적응 가능한 4족 보행로봇의 걸음새를 생성하고, 바이올로이드로 구성된 4족 보행로봇에 대하여 ODE 기반의 Webots 시뮬레이션을 통해서 보행 실험을 수행하고 결과를 분석한다.