• The Journal of the Acoustical Society of Korea
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• v.16 no.1E
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• pp.64-74
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• 1997

In many decision making systems, rule-based approaches are used to solve complex problems in the areas of pattern analysis and computer vision. In this paper, we present methods for generating fuzzy IF-THEN rules automatically from training data for pattern classification and high-level computer vision. The rules are generated by construction minimal approximate fuzzy aggregation networks and then training the networks using gradient descent methods. The training data that represent features are treated as linguistic variables that appear in the antecedent clauses of the rules. Methods to generate the corresponding linguistic labels(values) and their membership functions are presented. In addition, an inference procedure is employed to deduce conclusions from information presented to our rule-base. Two experimental results involving synthetic and real are given.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.321-329
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• 2002

Artificial neural network has been used for damage assessment by many researchers, but there are still some barriers that must be overcome to improve its accuracy and efficiency. The major problems with the conventional neural network are the necessity of many training patterns for neural network teaming process and ambiguity in the relationship of neural network structure to the convergence of solution. In this paper, the PNN is used as a pattern classifier to detect the damages of the railway bridge using dynamic response. The comparison between the mode shape and the natural frequency of structure as training pattern is investigated for approriate selection of the training pattern in the damage detection of railway bridge using the PNN.

• Physical Therapy Korea
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• v.10 no.3
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• pp.81-90
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• 2003

This study was conducted to assess the effects of the gait training method in incomplete spinal cord injured persons using an auto-walking machine. Persons with incomplete spinal cord injury level C or D on the American Spinal Injury Association impairment scale participated for eight weeks in an auto-walking training program. The gait training program was carried out for 15 minutes, three times per day for 8 weeks with an auto-walking machine. The foot rests of the auto-walking machine can be moved forward, downward, backward and upward to make the gait pattern with fixed on crank. The patient's body weight is supported by a harness during waking training. We evaluated the gait speed, physiologic cost index, motor score of lower extremities and the WISCI (walking index for spinal cord injury) level before the training and after the forth and eighth week of walking training. 1. The mean gait speed was significantly increased from .22 m/s at pre-training to .28 m/s after 4 weeks of training and .31 m/s after 8 weeks of training (p=.004). 2. The mean physiologic cost index was decreased from 4.6 beats/min at pre-training to 3.0 beats/min after 4 weeks and 2.0 beats/min after 8 weeks of training, but it was not statistically significant (p=.140). 3. The mean motor score of lower extrernities was significantly increased from 29.8 to 35.8 after 8 weeks of training (p=.043). 4. The mean WISCI level was significantly increased from level 10 to level 19 after 8 weeks of training (p=.007). The results of this study suggest that the gait training program using the auto-walking machine increased the gait speed, muscle strength and galt pattern (WISCI level) in persons with incomplete spinal cord injury. A large, controlled study of this technique is warranted.

• The Journal of Korea Robotics Society
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• v.14 no.3
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• pp.211-220
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• 2019

Surface electromyogram (sEMG), which is a bio-electrical signal originated from action potentials of nerves and muscle fibers activated by motor neurons, has been widely used for recognizing motion intention of robotic prosthesis for amputees because it enables a device to be operated intuitively by users without any artificial and additional work. In this paper, we propose a training-free unsupervised sEMG pattern recognition algorithm. It is useful for the gesture recognition for the amputees from whom we cannot achieve motion labels for the previous supervised pattern recognition algorithms. Using the proposed algorithm, we can classify the sEMG signals for gesture recognition and the calculated threshold probability value can be used as a sensitivity parameter for pattern registration. The proposed algorithm was verified by a case study of a patient with partial-hand amputation.

• Physical Therapy Korea
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• v.15 no.4
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• pp.50-58
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• 2008

The purpose of this study was to investigate the effects of the task-oriented training according to the application time with the change of motor and cognition function. Focal ischemic brain injury was produced in Sprague-Dawley rats (20 rats, $250{\pm}50$ g) through middle cerebral artery occlusion (MCAo). Before MCAo induction, all rats were trained in treadmill training and Morris water maze training for 1 week. Then they were randomly divided into groups: Group I : MCAo induction ($n_1$=5), Grop II: the application for simple treadmill task training after. MCAo induction ($n_2$=5). Group III: the application for Morris water maze cognitive task training after MCAo induction ($n_3$=5). Group IV: the application for progressive treadmill task training and Morris water maze cognitive task training after MCAo induction ($n_4$=5). Modified limb placing tests (MLPTs) and motor tests (MTs) were performed to test motor function and then Morris water maze acquisition test (MWMAT) and Morris water maze retention test (MWMRT) were performed to test cognitive function. For MTs, there were significant interactions among the groups with the time (p<.001). Group IV showed the steeper increasing pattern than those in other Groups on the 7th and 14th day. For MLPTs, there were significant interactions among the groups with the time (p<.001). The scores in Group III. IV had showed the more decreasing pattern than those in Group I, II since the 7th day and 14th day. For MWMAT, there were significant interactions among the groups with the time (p<.001). Group II found the Quadrant circular platform showed the steeper decreasing pattern than that in Group I on the 9th, 10th, 11th and 12th day. Group III. IV found the quadrant circular platform showed the slower decreasing pattern than that in Group I, II, For MWMRT, there were significant differences among the four groups (p<.001). The time to dwell on quadrant circular platform in Group IV on the 13th day was the longest compared with other groups. These results suggested that the combined task training was very effective to improve the motor and cognition function for the rats affected on their focal ischemic brain injury.

• The Journal of Korean Physical Therapy
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• v.21 no.1
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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 Academy of Orthopedic Manual Physical Therapy
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• v.27 no.1
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• pp.63-73
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• 2021

Background: This study was conducted to investigate the effects of pressure belt during proprioceptive neuromuscular facilitation sprinter pattern training using a Thera-band on leg muscle strength and gait in stroke patients with stroke. Methods: Nine patients with stroke underwent training five times a week for four weeks, and changes in the muscle strength and walking ability of the paralyzed leg before and after training were measured. Muscle strength was measured using a Digital muscle tester, and walking ability was measured using a G-WAKER and the timed up and go (TUG) test. Results: Results showed that the quadriceps, hamstring, tibialis anterior, gastrocnemius, cadence, stride length, and stance phase significantly increased (p<.05). The swing phase, gait cycle duration, and TUG test results significantly decreased (p<.05). Conclusion: This study demonstrated that a pressure belt is a very useful tool for improving muscle strength and walking ability in patients with stroke.

• PNF and Movement
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• v.17 no.1
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• pp.1-9
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• 2019

Purpose: This study investigates the effects of task-oriented training for a left trunk flexion pattern using real-time ultrasound imaging in a stroke patient with unilateral neglect symptoms. Methods: This study used the ABA experimental design, which is a single-subject research method among individual case research methods. For the ABA experimental design, changes in the degree of unilateral neglect, balance ability, and the thickness of the lateral abdominal muscle were visually analyzed during the baseline process, in the intervention period, and after the intervention. The experiments were performed 24 times in total for 8 times in each of the 3 periods. The unilateral neglect was measured using the Albert test, balance ability was measured using the Berg balance test, and the thickness of the lateral abdominal muscle was measured using ultrasound imaging. The subject was a 50-year-old male patient with unilateral neglect caused by right cerebral hemorrhage. He performed task-oriented training for a voluntary left trunk flexion pattern using real-time ultrasound imaging during the intervention period. Results: The result of comparing the data collected during the intervention period with the data point average of the baseline process showed that balance ability improved and the tendency line was above the baseline. The tendency line of unilateral neglect was below the baseline and showed a decreasing tendency. The thickness of the lateral abdominal muscle showed an increasing trend and the tendency line was above the baseline. Conclusion: The results of this study suggest that the task-oriented training for left trunk flexion pattern using real-time ultrasound imaging has a beneficial effect on balance ability, the degree of unilateral neglect, and the strength of the lateral abdominal muscle in unilateral neglect patients.

• Journal of Korean Institute of Industrial Engineers
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• v.28 no.1
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• pp.112-127
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• 2002

A useful pattern is a pattern that contributes much to learning. For a classification problem those patterns near the class boundary surfaces carry more information to the classifier. For a regression problem the ones near the estimated surface carry more information. In both cases, the usefulness is defined only for those patterns either without error or with negligible error. Using only the useful patterns gives several benefits. First, computational complexity in memory and time for learning is decreased. Second, overfitting is avoided even when the learner is over-sized. Third, learning results in more stable learners. In this paper, we propose a pattern 'utility index' that measures the utility of an individual pattern. The utility index is based on the bias and variance of a pattern trained by a network ensemble. In classification, the pattern with a low bias and a high variance gets a high score. In regression, on the other hand, the one with a low bias and a low variance gets a high score. Based on the distribution of the utility index, the original training set is divided into a high-score group and a low-score group. Only the high-score group is then used for training. The proposed method is tested on synthetic and real-world benchmark datasets. The proposed approach gives a better or at least similar performance.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.30 no.2
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• pp.7-13
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• 2022

As the demand for simulated flight training and interest in new technology training increase, this study analyzed the performance of flight simulator training and actual flight training subjects to confirm efficient flight simulator training curriculum. Summarizing the results of the study, found that flight simulator training had a significant positive effect on the actual flight training performance and in particular had a relatively large effect on the air maneuver, traffic pattern, cross country flight subjects. As a result of analyzing theoretical major classes that affect flight simulator training to verify the correlation, found that principle of air navigation, air traffic service, and helicopter flight theory were affected in order. The significance of this study was to identify the curriculum and ground lesson that should be focused on effectively performing flight simulator training in the helicopter private pilot course.