• Earthquakes and Structures
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• v.4 no.2
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• pp.219-239
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• 2013

The present paper aims at studying the seismic response of structures equipped with viscoelastic dampers (VED). The performance of such a passive control system is here analyzed using the energy balance concept, which leads to an optimal design process. The methodology is based on an energy index (EDI) whose maximization permits determination of the optimal mechanical characteristics of VED. On the basis of a single degree of freedom model, it is shown that the maximum value of EDI corresponds to a simultaneous optimization of the significant kinematic and static response quantities, independently of the input. By using the proposed procedure, the optimal design of new and existing structures equipped with VED, inserted in traditional bracing systems, are here analyzed and discussed.

• Korean Journal of Social Welfare
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• v.61 no.2
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• pp.349-370
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• 2009

This study examines the perceptions on work-family balance and compares the differences of diverse groups in Korea. The success of work-family policies depends on employees' perceptions of both the tangible and intangible aspects of work-family supportiveness. A survey was conducted to produce a instrument that could measure the perceptions of work-family balance. The survey is a conducted random sample, with random selection of respondents who are working and over the age of 25 in Seoul and the metropolitan area. The research design employed ANOVA to compare the perceptions on work-family policies for supporting work-life balance in society. There was a difference in spillover levels between workers in different groups such as gender, employment status, age, the number of children, family type by employment status, company size, and industry. The findings will inform policy-makers as they continue to develop policies that positively affect working people.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.222-229
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• 2020

Objective: The purpose of this study was to investigate the effect of treadmill exercise on the posture and walking speed of chronic stroke survivors with an ankle-foot orthosis. Design: Randomized controlled trial. Methods: Twenty-four chronic persons with chronic stroke admitted to Bobath Memorial Hospital in Seongnam city were divided into two groups by random blind method. Treadmill exercise with an elastic ankle-foot orthosis was performed in the experimental group and treadmill exercise was performed in the control group. The experiment was carried out for 6 weeks, and the experiment was carried out three times a week for 20 minutes per session. To measure the effect, static balance was measured using the MTD system before and after training, and the Berg Balance Scale (BBS) was used to measure functional balance. Results: There was a statistically significant difference between the 2 groups in the BBS measurement results for confirming the functional balance (p<0.05). Also, there was a significant difference between the 2 groups in single limb support time, step time and step length (p<0.05). Conclusions: In this study, it was found that treadmill exercise with an elastic ankle-foot orthosis in persons with chronic stroke was effective in maintaining functional balance, walking ability, step length, and step time. Therefore, it is necessary to use a flexible ankle-foot orthosis with proper treadmill exercise as a method of improving balance and walking speed of chronic stroke survivors.

• Physical Therapy Rehabilitation Science
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• v.3 no.1
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• pp.7-12
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• 2014

Objective: The purpose of this study was to investigate the effects of a three dimensional balance trainer in combination with a video-game system and visual feedback on balance recovery and gait function in subacute stroke patients. Design: Randomized controlled trial. Methods: Twenty-three subacute stroke patients were assigned to either an experimental (n=12) or a control group (n=11) using a random permuted block design and sealed envelopes. The experimental group received additional 3-dimensional balance training combined with visual feedback and a game program for 30 min/day, 5 days/week for 4 weeks. Both groups received 30-min of conservative physical therapy sessions based on neurodevelopmental therapy. Before and after the 20 sessions, walking abilities were evaluated by the the GaitRite system and balances were evaluated using the Berg Balance Scale (BBS). The Trunk Impairment Scale (TIS) was used to assess trunk muscle performances. Results: After the 4-week intervention, BBS and TIS scores were significantly increased in both groups (p<0.05), and increases in these scores were significantly greater in the experimental group (p<0.05). After the 4-week intervention, gait speed and cadence were significantly increased in both groups (p<0.05), and as was observed for BBS and TIS scores, changes of gait speed and cadence were significantly greater in the experimental group (p<0.05). Conclusions: The study shows that the 3-dimensional balance trainer combined with visual biofeedback and a video-game system provides a therapeutic means for improving balance and gait ability in subacute stroke patients.

• Journal of The Korean Society of Integrative Medicine
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• v.1 no.3
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• pp.63-78
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• 2013

PURPOSE : This study aims to investigate the positive correlation in pre-post test design between squat exercise on different baseform and the static/dynamic balance ability enhancement in adults. METHOD : This clinical study was designed into three different random-sampling adult groups (flat, balanced, vibration exercise device) and performed squat exercise. The static/dynamic balance ability was measured prior to the intervention and vice-versa. Balance was examined using the balance master 7.0 version systems. RESULT : 1) After the intervention, the controlled mat group in mCTSIB has showned the minimal mean value and the variation regards as acceptable by statistic value. 2) After the intervention, The mean value of LOS shows the minimal average variation in Randomised Trials, but the other two trials shows the maximal fluctuation. The difference variation regards as acceptable statistic value. 3)After the intervention, the mean value of mat group measrued as the maximal results, the difference variation regards as acceptable statistic value. 4)The striking correlation difference at mCTSIB has found in the vibration device exercise group, but LOS and Rhythmic W-S showed the correaltion in Mat group. CONCLUSION : The study found the positive correlation that enhanced balance ability on the different dynamic baseform squat exercise than static baseform environment. The significant difference found the balance pad squat effects on developing balance ability and the correlationship regards as statistically significant value.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.2
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• pp.1-11
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• 2023

PURPOSE: This study examined the immediate effects of applying ankle eversion taping using kinesiology tape in chronic stroke patients-design: a randomized cross-over trial. METHODS: Seventeen stroke patients underwent three interventions in random order. The subjects were initially assigned randomly to an ankle eversion taping, placebo taping, or no taping for each intervention. Ankle eversion taping was used for mechanical correction and was involved in ankle dorsiflexion and eversion. The tape was stretched by 30-40%. Placebo tapping was applied in the same form as eversion tapping but was not stretched. The balance ability was assessed using the Y-balance test. The gait ability was assessed by maximum foot pressure and time of stance phase, and gait speed was assessed using a 10 m walk test (10MWT). All measurements were performed immediately after the intervention. RESULTS: The results showed that the dynamic balance and stance phase time in chronic stroke patients was improved after ankle eversion taping. The ankle eversion taping conditions increased significantly (p < .05) compared to the placebo and no taping conditions. CONCLUSION: The application of ankle eversion taping that uses kinesiology tape instantly increased the gait ability of chronic stroke patients. On the other hand, more research will be needed to identify the long-term effects of ankle eversion taping.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.1
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• pp.22-28
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• 2010

Approximate analysis for a building installed with a friction damper is performed to get insight of its dynamic behavior. Energy balance equation is used to have a closed analytical form solution of dynamic magnification factor(DMF). It is found out that DMF is dependent on friction force ratio and resonance frequency. Approximation of DMF and equivalent damping ratio of a friction damper is proposed with such assumption that the building with a friction damper shows harmonic steady-state response and narrow banded response behavior near resonance frequency. Linear transfer function from input external force to output building displacement is suggested from the simplified DMF equation. Root mean square of a building displacement is derived under earthquake-like random excitation. Finally, design procedure of a friction damper is proposed by finding friction force corresponding to target control ratio. Numerical analysis is carried out to verify the proposed design procedure.

• Physical Therapy Rehabilitation Science
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• v.12 no.2
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• pp.167-176
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• 2023

Objective: The purpose of this study was to investigate the effects of anon-contact complex exercise program on muscle strength, fall efficacy, quality of life, and balance ability in older over 65 years of age. Design: A randomized controlled trial Methods: A total of 37 people in older over 65 years of age participated in the study. Random program was conducted and assigned to the experimental group (n=19) and the control group (n=18). Both groups performed the older people welfare center program. In addition, in the experimental group, a non-contact complex exercise program for muscle and balance exercise was performed. All interventions were performed 2 times a week, for a total of 6 weeks. chair stand test (CST), fall efficacy scale (FES), Euro quality of life 5 dimension (EQ-5D), Berg balance scale (BBS), timed up and go test (TUG), Fullerton advanced balance scale (FAB) were measured before and after the intervention to compare their effectiveness. Results: Both groups showed significant differences in CST, FES, EQ-5D, BBS, and TUG before and after intervention (p<0.05). FAB showed significant differences before and after intervention in all items except for FAB 8 and 9 items in the experimental group. In addition, the experimental group showed significant differences in CST, FES, BBS, TUG, FAB (except 1, 7, 8, 9) compared to the control group (p<0.05). Conclusions: The non-contact complex exercise program is an effective intervention method that has clinical significance in improving muscle strength, fall efficacy and static and dynamic balance abilities for the older over 65 years of age.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.850-854
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• 2009

Approximate analysis for a building installed with a friction damper is revisited to get insight of its dynamic behavior. Energy balance equation is used to have a closed analytical form solution of dynamic magnification factor (DMF) for the building with combined viscous and friction damping. It is found out that DMF is dependent on friction force ratio and resonance frequency. Linear transfer function from input external force to output building displacement is obtained by simplifying DMF equation. Root mean square of building displacement is derived under earthquake-like random excitation. Finally, design of friction damper is proposed by processing target control ratio, damping ratio factor, and friction force in sequence.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.1
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• pp.127-134
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• 2019

In terms of deep Reinforcement Learning (RL), exploration can be worked stochastically in the action of a state space. On the other hands, exploitation can be done the proportion of well generalization behaviors. The balance of exploration and exploitation is extremely important for better results. The randomly selected action with ε-greedy for exploration has been regarded as a de facto method. There is an alternative method to add noise parameters into a neural network for richer exploration. However, it is not easy to predict or detect over-fitting with the stochastically exploration in the perturbed neural network. Moreover, the well-trained agents in RL do not necessarily prevent or detect over-fitting in the neural network. Therefore, we suggest a novel design of a deep RL by the balance of the exploration with drop-out to reduce over-fitting in the perturbed neural networks.