• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.962-967
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• 1991

A counter balance valve is used as one part of hydraulic motor brake system. The function of this valve is to protect over-run or free falling of inertia load. But occasionally the brake system with counter balance valve makes some undesirable problems such as pressure surges or vibrations. In this study, for the purpose of easy estimation about dynamic characteristics of hydraulic system including counter balance valve, precise formulation describing fluid dynamics and valve dynamics under various boundary conditions were made. Dynamic characteristics were analysed by numerical integration using Runge-Kutta method, because the equations in this circuit with counter balance valve contain various nonlinear terms. Propriety of this analysis method is verified by experiment. For the purpose of obtaining fundamental data for preventing instability, this study experimented the effects of the spool taper, spring constant, cylindrical choke. And we developed double acting brake system integrated counter balance valve.

• Physical Therapy Korea
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• v.10 no.1
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• pp.29-35
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• 2003

Body weight support treadmill training is a new and promising therapy in gait rehabilitation of patients with hemiplegia. The purpose of this study was to identify the effects of body weight support treadmill training on gait and standing balance in patients with hemiplegia. Eighteen patients with hemiplegia participated in the study. A 10 m-timed walk test, measurements of step length and standing balance score were administered. Intervention consisted of body weight support treadmill training five times a week for 2 weeks. The data were analyzed by paired t-test. Body weight support treadmill training scoring of standing balance, step length and 10 m-timed walk test showed a definite improvement. Body weight support treadmill training offers the advantages of task-oriented training with numerous repetitions of a supervised gait pattern. The outcomes suggest that patients with hemiplegia can improve their gait ability and standing balance through body weight support treadmill training.

• Journal of the Korea Society of Computer and Information
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• v.20 no.11
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• pp.89-95
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• 2015

In this paper, we propose the method and development of custom-made golf insole recommender system to optimize the foot balance during golf swing. This system development procedures are as follows : (1) Using the measured data of the golf swing, the analysis of the individual golf hitting and balance will be done. (2) Based on the analysis results, the system will recommend the golf custom-made insole to optimize the individual balance using recommender algorithm. (3) After the golf custom-made insole is recommended, the modeling and design of the recommended insole is processed. Golf custom-made insole will be possible to reduce the excessive shaking and increase the lower-body supporting force. Therefore, we have expected that the recommended insole will improve the swing results through the optimization of golf swing balance. In the future, it is necessary to secure the higher validity and reliability through the more diverse experiments and research.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.347-361
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• 2023

Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.

• Journal of The Korean Society of Integrative Medicine
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• v.7 no.1
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• pp.1-8
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• 2019

Purpose : The purpose of this study was to examine the correlation between static and dynamic balance according to the virtual reality-based squat and conventional squat exercise. Methods : Twenty four participants were randomly assigned to the virtual reality-based squat (VRS) group (n=12) or conventional squat (CS) group (n=12). The static balance (C90 area, C90 angle, trace length, sway average velocity) and dynamic balance (forward, rearward, leftward, rightward) were measured using a force plate by BT4. The VRS group used the virtual reality system during 4 weeks, while the CS group underwent classical squat training. Independent t-test was used to test the homogeneity of the general characteristics of the subjects. The collected data was analyzed using the paired t-test for static and dynamic balance comparisons before and after exercise in both groups and Pearson's test for the correlation between static and dynamic balance according to the measured time. The significance level was set to 0.05. Results : There was no significant correlation between group and static and dynamic balance related variables (p>.05). There was a significant correlation between measurement time and static and dynamic balance related variables (p<.05). According to the measurement time, the static balance parameter C90 area in the VRS group after exercise was significantly decreased (p<.05). The values of forward, leftward and rightward in the VRS group were significantly increased after exercise (p<.05). Conclusion : It is suggested that 20 normal healthy adult men and women who have normal balance ability can improve their ability to control their posture by improving the balance ability when applying virtual reality-based squat exercise.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.41-50
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• 2007

The purpose of this study was to examine the effects of Task-oriented training on the balance, lapse time and MVC(Maximum Voluntary Contraction) of CVA(cerebral vascular accident) patients. The active balance equipment was used to measure of the static balance, lapse time and task-oriented training. The EMG technique was used to record muscle activitie of affected side of gluteus medius and vastus medialis. The raw EMG data were filtered with band pass filter (60Hz) to remove artifacts and then low pass filtered (20Hz) to find the linear envelope which resemble muscle tension curve. The experiment had been conducted at the department of physical therapy in J hospital in M city during 8weeks. The thirty patients experienced the stroke were participated: training group (15), control group (15). They were ambulatory with or without an assistive device. They were assessed on central perturbation(mm) in the static balance, lapse time(s) and MVC test(mV). The data were analyzed using repeated measured ANOVA. The results were as follows: After Task-oriented training, central perturbation and lapse time was significantly differences in both groups(p<.001), and MVC in gluteus medius were no significant differences in both groups, but vastus medialis was significant differences in both groups (p<.001).

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.1
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• pp.55-63
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• 2010

Purpose: The purpose of this study was to determine the effects of the BeHaS exercise program on balance and walking ability in middle-aged women with knee osteoarthritis. Method: Participants were 36 patients (experimental group: 18, control group: 18) with knee osteoarthritis. Women with knee osteoarthritis in the experimental group participated in the BeHaS exercise program for 65 to 90 minutes per session twice a week for 12 weeks. Data were collected by a structured interview and measurement tool from September 1, 2005 to March 30, 2006. Descriptive statistics, such as frequency, percentages, means, SD and t-test, Chi square test were used with the SPSS Win 12.0 to analyze the data. Results: There was a significant difference between the two groups for dynamic balance, but differences in balance and walking ability were only partially supported. Conclusion: These findings indicate that the BeHaS exercise program could be a good nursing intervention for health maintenance and promotion of patients with knee osteoarthritis. Further research is needed in order to confirm these findings in elderly people with osteoarthritis.

• Journal of Korean Clinical Nursing Research
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• v.22 no.1
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• pp.10-19
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• 2016

Purpose: This study was to develop a fall prevention program and test the effects of the program on the muscle strength, postural balance and fear of falling for elderly. Methods: This study was conducted using a nonequivalent control group pretest-posttest design. There were 21 participants in the experimental group and 22 in the control group. Data were collected from July to September 2015. Questionnaires were completed three times (at pretest and after 8 and 10 weeks). Data were analyzed using $x^2$ test, Fisher's exact test, t-test, and repeated measure ANOVA. Results: Lower extremity muscle strength and postural balance scores were significantly improved in the experimental group compared to the control group. However, fear of falling was not significantly different between the experimental and control groups. Conclusion: The study results indicate that fall prevention programs for the elderly can be useful to improve muscle strength and postural balance.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.276-279
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• 1997

A simple bio-feedback system was developed to monitor and to analyze patient's postural balance. Two load celIs were used to measure the weight of each side. A specially designed electronic circuit was made to pick up the weight signals and to feed into the data acquisition system. Clinical trials were also made on 20-30 year-old normal subjects and nine hemiplegia patients who had the potential instability in weight bearing. A Microsoft window-based software collected and analyzed the postural balance data. Normal subjects showed only 5% deviations of their body weight. However, hemipegic patients had significant weight shifts toward the healthy limb. With the present system, patients can also exercise their balance and weight bearing. The present system should be of convenience to monitor in real-time and analyze the postural balance control of hemiplegic patients.

• Korean Journal of Community Nutrition
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• v.2 no.4
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• pp.523-529
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• 1997

This study was conducted to obtain accurate data on the intake, digestibility and nitrogen balance of protein in Korean college women. Subjects were 8 female college students, aged from 21 to 23, and maintained their menu and life patterns regular during a 4- week study. The same amount of diet that the subjects had consumed, and feces and urine were collected and measured to extract their nitrogen content by Kjeldahl method. From this data, apparent digestibility and the body nitrogen balance were estimated by determing daily protein intake and excretion. The daily protein intake was 56.9$\pm$1.4g and daily fecal protein loss was 6.3$\pm$0.2g. The apparent digestibility of protein was 89.6$\pm$0.7$\%$. The daily nitrogen intake measured by Kjeldahl method was 9.43$\pm$0.2g. The urinary nitrogen excretion was 7.64$\pm$0.23g and fecal nitrogen excretion was 1.02$\pm$0.03g. The nitrogen balance indicated a positive balance of 0.45$\pm$0.18g. (Korean J Community Nutrition 2(4) : 523-529, 1997)