• The Journal of the Acoustical Society of Korea
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• v.29 no.6
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• pp.355-364
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• 2010

Considering biological safety, it is very important to measure acoustic power from ultrasonic array probe for diagnostic ultrasound imaging applications. In this paper, to measure acoustic power from each element on array probe for ultrasonic diagnostic equipment, we reconstruct and automate the acoustic power measurement system. The acoustic power from linear, phased and curved array were measured and analyzed. As a result of measurement, the effects caused by directivity of sound beam from curved array were founded. To remove these effects, we developed and applied the correction model. The proposed system is useful to evaluate characteristics of the acoustical output power of array probe.

• Journal of The Korean Society of Agricultural Engineers
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• v.62 no.6
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• pp.63-72
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• 2020

With the implementation of integrated water management policies, the need for information sharing with respect to agricultural water use has increased, necessitating the quantification of irrigation water supply using monitoring data. This study aims to estimate the irrigation water supply amount based on the relationship between the water level and irrigation canal discharge, and evaluate the reliability of monitoring data for irrigation water supply in terms of hydrology. We conducted a flow survey in a canal and reviewed the applicability of the rating curve based on the exponential and parabolic curves. We evaluated the reliability of the monitoring data using a reservoir water balance analysis and compared the calculated results of the supply quantity in terms of the reservoir water reduction rate. We secured 26 readings of measurement data by varying the water levels within 80% of the canal height through water level control. The exponential rating curve in the irrigation canal was found to be more suitable than the parabolic curve. The irrigation water supplied was less than 9.3-28% of the net irrigation water from 2017 to 2019. Analysis of the reservoir water balance by applying the irrigation water monitoring data revealed that the estimation of the irrigation water supply was reliable. The results of this study are expected to be used in establishing an evaluation process for quantifying the irrigation water supply by using measurement information from irrigation canals in agricultural reservoirs.

• Journal of Korean Physical Therapy Science
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• v.26 no.3
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• pp.70-75
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• 2019

Purpose: The purpose of this study was to investigate the changes of static and dynamic balance control ability according to the stability of shoes in elderly woman and female university student. Design: Cross-sectional study. Methods: Six elderly women and seven female university students were recruited for this study. The subject's static and dynamic balance were evaluated while wearing two different types of shoes (comfortable running shoe and masai walking shoe). The BT4 system was used to measure the static (postural sway area and velocity) and dynamic balance (limit of stability on forward, backward and left and right side). The measurement of static and dynamic balance control ability was performed in standing posture wearing comfortable running shoes and masai walking shoes. Results: In the static balance control ability, both female university students and elderly women showed significant increase in postural sway area and velocity when wearing unstable shoes (p<0.05) In addition, in the dynamic balance control ability, both female university students and elderly women showed significant decrease in limit of stability on forward and backward when wearing unstable shoes (p<0.05). Conclusion: In selecting shoes for the elderly, the stability of shoe should be considered for prevention of falls.

• Journal of the Korea Convergence Society
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• v.9 no.10
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• pp.141-147
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• 2018

The purpose of this study was to investigate the effects of taping, stretching and ultrasound on convergent balance ability with induced ankle muscle fatigue. Thirty-nine healthy adults participated voluntarily in this study. After the induction of their's ankle muscle fatigue, they were randomly assigned as taping, static stretching, or ultrasound group. And the intervention corresponding to each group was applied. Before and after induced ankle fatigue and after intervention, balance ability was measured using Space Balance 3D. Balance ability was no significant difference among groups (p>.05), but significantly increased within all three groups (p<.001). Therefore, the taping, static stretching, and ultrasound on ankle muscle fatigue are effective in convergent balance ability. In future studies, it is necessary to prove the therapeutic effect by applying various measurement variables and therapeutic intervention.

• Physical Therapy Rehabilitation Science
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• v.9 no.4
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• pp.275-280
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• 2020

Objective: Compression wear is an external aid which promotes performance and recovery, diminishes muscular microtrauma, reduces muscle fiber recruitment, improves neuromechanics, enhances coordinative activities, and reduces the perceived exertion. The purpose of this study was to investigate the relationship between athletic taping and compression wear on dynamic postural balance in healthy young men. The hypothesis was that the athletic taping and compression wear would affect dynamic postural balance, with athletic taping having a different effect on dynamic postural balance in healthy young adults. Design: Cross-sectional study. Methods: Thirty-seven healthy young men participated in this study. To examine the association between athletic taping and compression wear, 3 clinical measurement tools, including 5 times sit-to-stand (5xSTS), one-leg standing (OLS) test, and Y-balance test (YBT) in 5 different conditions, namely (1) non-supporting, and support with (2) athletic taping, (3) regular compression wear, (4) silicon compression wear, and (5) double-fiber compression wear were used. Results: The distance of the Y-balance test (YBT) on both the dominant and non-dominant sides showed a statistically difference among the 5 supporting conditions (p<0.05). The distance measured via the YBT in the non-support condition was significantly different than that in the other four supporting conditions (p<0.05). However, 5xSTS and OLS were not significantly different in these supporting conditions. Conclusions: The results of this study suggest that athletic taping, silicon compression wear, and double-fiber compression wear were more effective for dynamic balance than non-supporting and regular compression wear.

• Journal of The Korean Society of Integrative Medicine
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• v.11 no.1
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• pp.121-130
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• 2023

Purpose : This study aimed to investigate the effect of blood flow restriction exercise on ankle muscle strength and balance ability to achieve maximum efficiency with the same exercise intensity and time. Methods : Twenty-six adults are randomly assigned to experimental group (n=13) and comparison group (n=13). The experimental group performed ankle joint strength exercises with blood flow restriction applied while the comparison group performed ankle joint strength exercises without blood flow restriction applied three times a week for four weeks. The digital muscle measurement, Y-balance test, and Cumberland ankle instability tool were used to evaluate the subject's muscle strength, dynamic balance, and ankle instability index before and after the intervention. Results : In within-group comparison muscle strength, all the two groups showed significant improvements post intervention (p<.05). In between-group comparison, there was significant difference in the change of dorsiflexion, eversion strength pre and post intervention (p<.05). but plantarflexion was no significant difference between pre and post intervention in the group comparison (p>.05). In within-group comparison dynamic balance, all the two groups showed significant improvements post intervention (p<.05). In between-group comparison, there was no significant difference in the change of Y-balance score pre and post intervention (p>.05). In within-group comparison ankle instability index, all the two groups showed significant improvements post intervention (p<.05). In between-group comparison, there was no significant difference in the change of CAIT score pre and post intervention (p>.05). Conclusion : The results of this study show that ankle joint strength exercise improved the strength and balance ability of those complaining of chronic ankle instability, and ankle joint strength exercise applied with blood flow restriction was more effective in dorsiflexion and eversion strength exercise than ankle joint strength exercise without blood flow restriction.

• Journal of the Korean Society of Physical Medicine
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• v.11 no.1
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• pp.11-21
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• 2016

PURPOSE: This study was examined the effects of aerobic exercise using a step box and lower extremity strengthening exercise with an elastic band on the balance ability and lower extremity muscular strength in elderly subjects. METHODS: Forty-one healthy adults were randomly divided into experimental group 1 (Exp 1, n=14), experimental group 2 (Exp 2, n=14), and a control group (n=13). The Exp 1 conducted lower limb strengthening exercise using an elastic band and the Exp 2 performed aerobic exercise with a step box 50 minutes per day, twice per week, for eight weeks. RESULTS: There was significant increase in the Exp 1 and Exp 2 in comparison of the change of lower limb muscle strength according to measurement time (p<.05). But there was no significant difference according to intervention methods. In one-leg standing test change among the three groups after the intervention, the Exp 1 and Exp 2 saw significant improvement compared to the control group (p<.05) but there was no significant difference according to intervention methods. The change of the functional reaching test results, the Exp 1 and Exp 2 saw significant improvement according to the time of measurement. In the change of the Timed Up and Go test, there was significant improvement in the Exp 1 and Exp 2 compared to the control group (p<.01), but there was no significant difference according to intervention methods. CONCLUSION: Exercise to lower extremity strengthening program accompanied with aerobic exercise is considered more effective in dynamical balance and ability to walk.

• Journal of information and communication convergence engineering
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• v.16 no.1
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• pp.38-42
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• 2018

In this paper, we consider measurement allocation problem in a spatially correlated sensor field. Our goal is to determine the probability of each sensor's being measured based on its contribution to the estimation reliability; it is desirable that a sensor improving the estimation reliability is measured more frequently. We consider a spatial correlation model of a sensor field reflecting transmission power limit, noise in measurement and transmission channel, and channel attenuation. Then the estimation reliability is defined distortion error between event source and its estimation at sink. Motivated by the correlation nature, we model the measurement allocation problem into a cooperative game, and then quantify each sensor's contribution using Shapley value. Against the intractability in the computation of exact Shapley value, we deploy a randomized method that enables to compute the approximate Shapley value within a reasonable time. Besides, we envisage a measurement scheduling achieving the balance between network lifetime and estimation reliability.

• The Korean Journal of Coaching Psychology
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• v.7 no.1
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• pp.33-57
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• 2023

This study conducted an e-mail survey of office workers working in large companies in Seoul and Gyeonggi-do to verify the structural relationship between meaning in work, work-life balance, life satisfaction, and depression. The study participants were 329 male and 176 female workers, and a total of 505 ($\bar{M}=38.0$ yrs, $\bar{SD}=8.1$ yrs), and the measurement tools used the Korean version of work meaning scale, work-life balance scale, Korean version of life satisfaction scale, and shortened CES-D. After establishing a research model on the structural relationship between major variables, the measurement model and structural model were verified using the collected data, and the applicability of the model was reviewed through comparison according to group classification by gender and age group. As a result of the analysis, it was found that the work-life balance had a partial mediating effect on the effect of the meaning in work on the life satisfaction and depression of office workers. As a result of analyzing the multi-group structural model by age group, the mediating effect of work-life balance did not differ by age in the effect of meaning in work on life satisfaction, but the mediating effect of work-life balance on meaning in work on depression was different by age. These results suggest that the emphasis needs to vary depending on the target group in the practice of individual and group coaching and counseling.

• Journal of Power Electronics
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• v.12 no.1
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• pp.88-97
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• 2012

This paper presents a method for the digital control of a high power factor AC/DC converter employing the power balance control technique to achieve a fast response of the output voltage control. To avoid the effects of an output voltage ripple in the voltage control loop, the average output voltage is sampled and used as a feedback signal for the output voltage controller. The proposed control technique was verified by simulations using MATLAB/Simulink and its implementation was realized by a dsPIC30F4011 digital signal processor to control a CUK topology AC/DC converter with a 48V output voltage and a 250 W output power. The experimental results agree with the simulation results. The proposed control technique achieves a fast transient response with a lower line current distortion than is achieved when using a conventional proportional-integral controller and the power balance control technique with the conventional sampling method.