• 한국전문물리치료학회지
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• 제11권2호
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• pp.1-8
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• 2004

Motor skill learning can be acquired implicitly without consciousness of what is being learned. The purpose of this study was to examine the characteristics of implicit motor learning in young and elderly people using a perceptual-motor task. Forty normal young and elderly subjects participated. A modified version of the Serial Reaction Time Task (SRTT) using six blocks of twelve perceptual motor sequences was administered. The paradigm consisted of the first random sequence block followed by the four patterned blocks and another random block. In each block, the go signal consisted of an asterisk displayed in the one of the four parallel arrayed boxes in the middle of the screen. Subjects were instructed to push the corresponding response buttons as quickly as possible. Young subjects demonstrated shorter reaction times during the consecutive patterned blocks reflecting appropriate learning accomplished. Elderly subjects were able to learn a perceptual-motor task with implicit knowledge, but the performance was lower than that of the young persons. These results indicated that implicit sequence learning is still preserved in elderly adults, but the rate of learning is slower.

• 제어로봇시스템학회논문지
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• 제3권6호
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• pp.555-562
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• 1997

With only the classical PID controller applied to control of a DC motor, good (target) performance characteristic of the controller can be obtained if all the model parameters of DC motor and operating conditions such as external load torque, disturbance, etc. are known exactly. However, in case when some of system parameters or operating conditions are uncertain or unknown, the fixed PID controller does not guarantee good performance, which is assumed with precisely known system parameters and operating conditions. In view of this and the robustness enhancement of DC motor control system, we propose a PID learning controller which consists of a set of learning rules for PID gain tuning and learning of an auxiliary input. The proposed PID learning controller is shown to drive the state of uncertain DC motor system with unknown system parameters and external load torque to the desired one world wide asymptotically. Computer simulation and experimental results are given to demonstrate the effectiveness of the proposed PID learning controller, thereby showing its superiority to the conventional fixed PID controller.

• The Journal of Korean Physical Therapy
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• 제20권3호
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• pp.1-7
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• 2008

Purpose: Implicit motor learning is the capacity to acquire skill through physical practice without conscious awareness of what elements of performance improved. This study investigated whether subacute stroke patients can implicitly learn a perceptual-motor task. Methods: We recruited 12 patients with subacute stroke and 12 age-matched controls. All participants performed a perceptual-motor task that involved pressing a button corresponding with colored circles (blue, green, yellow, red) on a computer screen. The task consists of 7 blocks composed of 10 repetitions for a repeating 12-element sequence (total 120 responses). Results: Both groups demonstrated significant improvement in acquisition performance. Reaction times deceased in both groups at similar rate within the sequential block trials (2-5 blocks), and reaction times increased at a similar rate when the task paradigm was transferred from the sequential block trial to the random block trial (5-6-7 blocks). Conclusion: The results of this study suggest that patients with sub-actue stroke can implicitly learn a perceptual motor skill. Although explicit instructions should be used to focus the learner's attention rather than provide information about the task, the application of implicit motor learning strategies in the rehabilitation setting may be beneficial.

• 한국전자통신학회논문지
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• 제10권3호
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• pp.327-332
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• 2015

교육용 로봇은 과학의 기초 원리를 배우고 과학적 창의성을 키우는 것에 효과적인 교육 도구로 소개되면서 방과 후 학습에 적용되어 과학 교육을 위한 교육용 키트의 구성이 바뀌고 있다. 중소기업을 중심으로 과학적 창의성을 키우는 도구로서 다양한 교육용 로봇 기술과 학생들을 위한 다양한 범주의 게임로봇기술이 개발되고 있고, 기존의 mp3 음악이나 e-Learning 콘텐츠의 제공과 같이 로봇용 전문콘텐츠를 다운받아 학습에 활용하는 기술을 개발 중에 있으나 아직 전문 커뮤니티 형성이 미흡한 편이다. 현재는 사용자가 손쉽게 제어가 가능한 인터페이스 모듈용 모터가 개발이 되어있지 않아 1포인트 드래그 연동 스마트터치 제어용 다이나믹 모터 개발이 필요하다.

• 국제물리치료학회지
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• 제1권2호
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• pp.91-98
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• 2010

This study is intended to examine the motor skill learning and treadmill exercise on motor performance and synaptic plasticity in the cerebellar injured rats by harmaline. Experiment groups were divided into four groups and assigned 15 rats to each group. Group I was a normal control group(induced by saline); Group II was a experimental control group(cerebellar injured by harmaline); Group III was a group of motor skill learning after cerebellar injured by harmaline; Group IV was a group of treadmill exercise after cerebellar injured by harmaline. In motor performance test, the outcome of group II was significantly lower than the group III, IV(especially group III)(p<.001). In histological finding, the experimental groups were destroy of dendrities and nucleus of cerebellar neurons. Group III, IV were decreased in degeneration of cerebellar neurons(especially group III). In immunohistochemistric response of synaptophysin in cerebellar cortex, experimental groups were decreased than group I. Group III's expression of synaptophysin was more increased than group II, IV. In electron microscopy finding, the experimental groups were degenerated of Purkinje cell. These result suggest that improved motor performance by motor skill learning after harmaline induced is associated with dynamically altered expression of synaptophysin in cerebellar cortex and that is related with synaptic plasticity.

• The Journal of Korean Physical Therapy
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• 제21권1호
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• pp.81-87
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• 2009

Purpose: Human brain was lateralized to dominant or non-dominant hemisphere, and could be reorganized by the processing of the motor learning. We reported four cases which showed the changes of the cortical activation patterns resulting from two weeks of training with the serial reaction time task. Methods: Four right-handed healthy subjects were recruited, who was equally divided to two training conditions (right hand training or left hand training). They were assigned to train the serial reaction time task for two weeks, which should press the corresponding four colored buttons as fast as accurately as possible when visual stimulus was presented. Before and after two weeks of training, reaction time and function magnetic resonance image (fMRI) was acquired during the performance of the same serial reaction time task as the training. Results: The reaction time was significantly decreased in all of subjects after training. Our fMRI result showed that widespread bilateral activation at the pre scanning was shifted toward the focused activation on the contralateral hemisphere with progressive motor learning. However, the bilateral activation was still remained during the performance of the non-dominant hand. Conclusion: These findings showed that the repetitive practice of the serial reaction time task led to increase the movement speed and accuracy, as described by motor learning. Such motor learning induced to change the cortical activation pattern. And, the changed pattern of the cortical activation resulting from motor learning was different each other in accordance with the hand dominance.

• The Journal of Korean Physical Therapy
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• 제22권5호
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• pp.109-115
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• 2010

Purpose: This study was to delineate the structural change of neural pathway after sequential motor learning using diffusion tensor imaging (DTI). Methods: The participants were 16 healthy subjects, which were divided by training (n=8) and control (n=8) group. The task for the training was the Serial Reaction Time Task (SRTT) which was designed by Superlab program. When the 'asterisk' shows up in the 4 partition spaces on the monitor, the subject presses the correct response button as soon as possible. The training group participated in the training program of motor learning with SRTT composed of 24 digits pattern in one hour per daily through 10 days during 2 weeks. Results: In the behavioral results the training group showed significant changes in the increase of response number and the reduction of response time than those of the control group. There was significant difference in the left inferior frontal area in the fractional anisotropy (FA) map of the training group in DTI analysis. Conclusion: Motor sequential learning as like SRTT may be needed to the learning of language and visuospatial processing and may be induced for the experience-dependent structural plasticity during short period.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.331-333
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• 1994

A learning method for induction motor trajectory using neuro-fuzzy networks (NFN) based on fusion of fuzzy logic theory and neural networks is proposed. The premise and consequent parameters of the NFN affecting the controllers performances are modified during the learning stages by the proposed learning method to implement an optimal controller only with pre-determined target trajectory and the least amount of knowledge about an induction motor. The induction motor position control system is simulated to verify the effectiveness of the learned NF controller(NFC). The simulation results shows that the proposed learning method has good dynamic performance and small steady state error.

• 한국인공지능학회지
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• 제11권4호
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• pp.15-20
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• 2023

Machine learning is comprised of supervised learning, unsupervised learning and reinforcement learning as the type of data and processing mechanism. In this paper, as input and output are unclear and it is difficult to apply the concrete modeling mathematically, reinforcement learning method are applied for crawling robot in this paper. Especially, Q-Learning is the most effective learning technique in model free reinforcement learning. This paper presents a method to implement a crawling robot that is operated by finding the most optimal crawling method through trial and error in a dynamic environment using a Q-learning algorithm. The goal is to perform reinforcement learning to find the optimal two motor angle for the best performance, and finally to maintain the most mature and stable motion about EV3 Crawling robot. In this paper, for the production of the crawling robot, it was produced using Lego Mindstorms with two motors, an ultrasonic sensor, a brick and switches, and EV3 Classroom SW are used for this implementation. By repeating 3 times learning, total 60 data are acquired, and two motor angles vs. crawling distance graph are plotted for the more understanding. Applying the Q-learning reinforcement learning algorithm, it was confirmed that the crawling robot found the optimal motor angle and operated with trained learning, and learn to know the direction for the future research.

• The Journal of Korean Physical Therapy
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• 제23권2호
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• pp.85-90
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• 2011

Purpose: The contribution of the supplementary motor area (SMA) to the control of voluntary movement has been revealed. We investigated the changesin the SMA for motor learning of the reaching movement in stroke patient using functional MRI. Methods: The subject was a right-handed 55 year-old woman with left hemiparesis due to an intracerebral hemorrhage. She performed reaching movement during fMRI scanning before and after reaching training in four weeks. The motor assessment scale and surface EMG were used to evaluate the paretic upper limb function and muscle activation. Results: In the fMRI result, contralateral primary sensorimotor cortex (SM1) was activated before and after training. SMA was only activated after training. In addition, muscle activation of the paretic upper limb was similar to that of the unaffected upper limb after training. Conclusion: These findings suggest SMA is related to the execution of a novel movement pattern resulting in motor learning in stroke patients.