• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.559-570
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• 2008

This paper proposes an improved particle swarm optimization named PSO with Controllable Random Exploration Velocity (PSO-CREV) behaving an additional exploration behavior. Different from other improvements on PSO, the updating principle of PSO-CREV is constructed in terms of stochastic approximation diagram. Hence a stochastic velocity independent on cognitive and social components of PSO can be added to the updating principle, so that particles have strong exploration ability than those of conventional PSO. The conditions and main behaviors of PSO-CREV are described. Two properties in terms of "divergence before convergence" and "controllable exploration behavior" are presented, which promote the performance of PSO-CREV. An experimental method based on a complex test function is proposed by which the proper parameters of PSO-CREV used in practice are figured out, which guarantees the high exploration ability, as well as the convergence rate is concerned. The benchmarks and applications on FCRNN training verify the improvements brought by PSO-CREV.

• 한국전문물리치료학회지
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• 제15권4호
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• pp.10-17
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• 2008

The purpose of this study was to determine the therapeutic effect of slope changes of the treadmill with body weight-supported training on gait characteristics in patients with hemiplegia. The volunteered subjects were divided into 3 groups based upon slope changes: control group ($0^{\circ}$ incline), $7^{\circ}$ group ($7^{\circ}$ incline), $12^{\circ}$ group ($12^{\circ}$ incline), They were trained the body weight-supported treadmill training (BWSTT) for 8 weeks. All subjects were supported up to 40% of their body weight on the treadmill training and the support was gradually decreased to 0~10% as the subjects were adapted to the training. There were significant improvements of walking velocity, step length of the affected side, the asymmetry ratio of step length in $7^{\circ}$ group (57.80 cm/s, 67.25 cm, .14), $12^{\circ}$ group (71.00 cm/s, 71.00 cm, .11) than control group (40.62 cm/s, 55.00 cm, .74) (p<.05): there were no differences between $7^{\circ}$ group and $12^{\circ}$ group in the all outcomes (p>.05). Both $7^{\circ}$ group and $12^{\circ}$ group scored higher than the control group in those outcomes and finally the effects of slopes changes of the treadmill were effective on gait characteristics of patients. But it s till remains undetermined what degree on the treadmill might be better to train the hemipareric patients. Therefore, more studies are required to look into minutely the changes of slopes of the treadmill influencing on gait characteristics.

• Advances in aircraft and spacecraft science
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• 제7권4호
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• pp.353-369
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• 2020

This paper presents the flutter analysis and optimum design of axially functionally graded box beam cantilever wing section by considering various geometric and material parameters. The coupled dynamic equations of the continuous model of wing system in terms of material and cross-sectional properties are formulated based on extended Hamilton's principle. By expressing the lift and pitching moment in terms of plunge and pitch displacements, the resultant two continuous equations are simplified using Galerkin's reduced order model. The flutter velocity is predicted from the solution of resultant damped eigenvalue problem. Parametric studies are conducted to know the effects of geometric factors such as taper ratio, thickness, sweep angle as well as material volume fractions and functional grading index on the flutter velocity. A generalized surrogate model is constructed by training the radial basis function network with the parametric data. The optimized material and geometric parameters of the section are predicted by solving the constrained optimal problem using firefly metaheuristics algorithm that employs the developed surrogate model for the function evaluations. The trapezoidal hollow box beam section design with axial functional grading concept is illustrated with combination of aluminium alloy and aluminium with silicon carbide particulates. A good improvement in flutter velocity is noticed by the optimization.

• 한국운동역학회지
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• 제14권1호
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• pp.1-12
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• 2004

The purpose of this study is to provide training materials for practical use by investigating the kinematical variables of the successful landing by the type of the salto backward such as Tuck, Pike. For this study, the subjects are 4 male national gymnasts using 3-dimensional cinematographic method. Based on the results of this study, the conclusions are drawn as follows. 1. In flight phase, Tuck and Pike show fast extension after completing minimum angle of hip joint passing through the peak. It is very important factor to control body with gaining time before landing while decreasing the velocity of flight rotaion. 2. In Landing phase, the angles of each joint for successful landing are shown as $92deg{\sim}100deg$ for knee angle, $52deg{\sim}57deg$ for hip angle, and $56deg{\sim}70deg$ for shoulder angle. 3. Tuck and Pike dramatically decrease the height of COG, and horizontal/vertical velocity of COG from TD to LD. Also, it is shown that the knee angle, the hip angle and the shoulder angle decrease drastically. On the other hand, the angular velocity of trunk rotation shows negative direction and due to this, the angle of trunk rotation is shown as re-flexion.

• 대한물리의학회지
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• 제11권3호
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• pp.133-139
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• 2016

PURPOSE: The purpose of this study is to examine the impact of balance training on a three-dimensional balance trainer that provides the up-and-down vertical movement of the knee joint and left-and-right horizontal movement, along with visual feedback on the functional ability of children with spastic cerebral palsy (CPs). METHODS: 8 CPs participated in this study. The experiment was implemented for 40 minutes, three times a week for a total of six weeks. The subjects received general physiotherapy for 15 minutes in each session focused on balance and walking, as based on the neuro-developmental treatment theory. Balance training was performed for 20 minutes on a three-dimensional balance trainer where knee joint movement providing visual feedback is applied. The evaluations were conducted before and after the test, and posture sway was measured using 10 Meter Walking Test (10MWT), Timed Up & Go Test (TUG), and the Good Balance System to evaluate the functional ability and balance of the subjects RESULTS: 10MWT was not statistically significant (p>.05). On the contrary, TUG and postural sway indicate static balance showed a statistically significant decrease (p<.05). In a static balance test using the Good Balance System, the average moving speed statistically significantly decreased in the AP and ML directions (p<.05), and the mean velocity moment also significantly decreased (p<.05). CONCLUSION: These findings suggested that balance training using the three-dimensional balance trainer, with the features of visual feedback and up-and-down knee joint movement effects on increasing dynamic and static balance.

• PNF and Movement
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• 제5권2호
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• pp.47-54
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• 2007

Purpose : The purpose of this study were to determine the effect of a Elastic Theraband Exercise Based of PNF L/E pattern on the gait of the chronic Hemiplegic Patients. Methods : We selected the 20 chronic Hemiplegic Patients not given treatment now and divided them into two groups of both 10 Elastic Theraband group and 10 Self Exercise. The first group went through a Elastic Theraband Exercise Based of PNF L/E pattern 30 minutes a day, 5 times a week, for 6 weeks. Exercise used to blue elastic band which 2 patterns of PNF by 1) hip extension - abduction - internal rotation with knee extension. 2) hip flexion - adduction - external rotation with knee flexion. The latter group experienced Self Exercise, 30 minutes a day, 5 times a week, for 6 weeks. Firstly, we measured the absolute improvement of gait velocity(m/s), cadence(steps/min) among walking characters. Secondly, we measured the functional walking ability such as Functional Ambulatory Category(FAC, score out of 5), Modified Motor Assesment Scale(MMAS, score out of 6). Data analysis was performed with using SPSS 12.0 win program. The descriptive analysis was used to obtain average and standard deviation. The independent t-test and the paired t-test were used to compare both the groups about pre and post training test. Treatment effects were established by pre and post assessment. Subjects tolerated the training well without side-effects. Therefore, the results of this study were as follows; Results : 1. There was a more significant improvement of Gait velocity(0.12m/s) Elastic Theraband group(p<.05). 2. There was a more significant improvement of cadence(9.40steps/min) Elastic Theraband group(p<.05). Conclusion : As we can see from above, the findings suggest that Elastic Theraband may be more effective than the Self Exercise for improving some gait parameters such as Gait velocity and Cadency. This conclusion also suggest that Elstic Theraband is more effective for the improvement of gait of chronic Hemiplegic Patients.

• 지구물리와물리탐사
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• 제26권2호
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• pp.84-93
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• 2023

지도 학습 기반 딥러닝 탄성파 역산은 소규모 영역을 대상으로 하는 합성 자료 예제에서 성공적인 역산 성능을 보여주었다. 지도 학습 기반 딥러닝 탄성파 역산은 시간 영역 파동장을 입력, 지하 속도 모델을 출력으로 사용하는데, 시간 영역 파동장은 다양한 파동 정보를 포함하고 있어 자료의 크기가 상당히 크다. 따라서 대량의 데이터로 훈련하는 지도 학습 기반 딥러닝 탄성파 역산을 현장 규모의 자료에 적용하는 연구는 아직까지 수행되지 못하고 있다. 본 연구에서는 지도 학습 기반 딥러닝 탄성파 역산 기법을 현장 규모의 자료에 적용하기 위해 시간 영역 파동장 대신 라플라스 영역 파동장을 입력으로 사용하여 지하 속도 모델을 예측하였다. 시간 영역 파동장 대신 라플라스 영역 파동장을 사용하면 결과의 해상도는 다소 떨어지지만 입력 자료의 크기가 크게 감소하여 신경망 훈련이 빨라지게 된다. 또한, 큰 격자 간격을 사용할 수 있어 현장 자료 크기의 속도 모델을 효율적으로 예측할 수 있으며 이를 통해 얻은 결과는 후속 역산의 초기 모델로 사용될 수 있다. 신경망 훈련을 위해 현장 자료 크기를 가지는 대량의 합성 속도 모델과 라플라스 영역 파동장을 생성한 후 인공 합성 자료만으로 신경망을 훈련시켰다. 또한, 해양 탄성파 탐사를 시뮬레이션하기 위해 견인 스트리머 취득 조건을 채택하였다. 테스트 자료와 벤치마크 모델을 이용한 수치 예제에서 훈련된 신경망을 테스트한 결과, 적절한 배경 속도 모델들을 얻을 수 있었다.

• 대한물리의학회지
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• 제9권3호
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• pp.315-324
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• 2014

PURPOSE: This study aimed to determine the correlation of weight bearing ability at the affected side with balance and gait abilities for the development of pressure biofeedback based equipment to stroke patients. METHODS: This study included 35 patients with stroke patient. The tests were conducted to determine the weight bearing ratio while pushing a step forward the affected side, static balance ability using the total length of COP(Center of pressure), sway velocity of COP, COP velocity at the X and Y axis. Functional reaching test (FRT), berg balance scale (BBS) were used to assess the dynamic balance ability and timed up and go test (TUG), 10m walk test (10mWT) were used assess the gait ability respectively. In order to determine the correlation between measured variables, bivariate correlation analysis was conducted. RESULTS: A significant correlation of the weight bearing ratio were shown with COP total length and velocity(r=-.34), Y-axis velocity(r=-.39), FRT(r=.42), BBS(r=.54), TUG (r=-.39), and 10m walking test (r=-.42). CONCLUSION: This study result showed that as patients with stroke had more weight bearing ratio at the affected side, not only their static and dynamic balance abilities increased more but also functional gait ability improved more. These results mean that, to improve stroke patients' static, dynamic balance ability and gait ability, weight bearing training with the affected side foot placed one step forward necessary for gaits are important.

• 한국운동역학회지
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• 제33권4호
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• pp.175-184
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• 2023

Objective: The purpose of this study is to investigate the effects of human motion and javelin kinematics during the energy transfer in javelin throwing on records, and to provide evidence-based training insights for athletes and coaches to enhance records. Method: Three javelin throw athletes (age: 22.67 ± 0.58 years, height: 178.33 ± 7.37 cm, weight: 83.67 ± 1.15 kg) were recruited for this study. Each athlete attempted ten maximum record trials, and the kinematic data from each performance were analyzed to determine their influence on the records. The Theia3d Markerless system was used for motion analysis. Results: Key factors were modeled and identified at each moment. In E1, main variables were COM Y (𝛽 8.162, p<.05) and COM velocity Z (𝛽 -72.489, p<.05); in E2, COM X (𝛽 -17.604, p<.05); in E3, COM X (𝛽 -18.606, p<.05), COM velocity Y (𝛽 38.694, p<.05), and COM velocity X (𝛽 66.323, p<.05). For the javelin throw dynamics in E3, key determinants were Attitude angle and Javelin velocity in the Y-axis. Conclusion: The study reveals that controlled vertical movement, center of mass management during braking, and enhanced pelvic rotation significantly improve javelin throw performance. These kinematic strategies are critical for record enhancement in javelin throwing.

• 한국지반공학회논문집
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• 제40권4호
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• pp.127-135
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• 2024

해당 논문의 목적은 deep neural network(DNN) 알고리즘을 이용하여 불포화토 지반의 압축파 속도와 간극률 간의 관계를 도출하는 것이다. 입력 인자는 error norm 방법으로 각각의 값이 간극률에 미치는 영향을 조사하였으며, 결론적으로 압축파 속도가 간극률 산정에 제일 큰 영향을 주는 것으로 나타났다. 압축파 속도와 간극률은 현장 및 실내 실험을 통해 도출하였으며, 총 266개의 수치 데이터를 이용하였다. DNN 적용 결과는 매 횟수마다 계산된 MSE 손실로 표현하였으며, 초반의 계산 횟수 단계에서 거의 0에 수렴하는 결과를 도출하였다. 예측된 간극률은 train과 validation으로 구분하여 분석하였으며, 실제 데이터와 비교하였을 경우 결정계수는 각각 0.97과 0.98로 나타나 높은 신뢰성을 보여준다. 해당 연구에서는 error norm 분석을 통해 민감도가 작은 인자는 배제하고 영향성이 높은 인자를 통해 종속 변수를 예측하는 방법론을 제시하였다.