• PNF and Movement
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• v.9 no.3
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• pp.31-39
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• 2011

Purpose : The purpose of this study was to evaluate the criterion-related validity of the Berg balance test between fallers and non-fallers in individuals with Parkinson's disease. Methods : Thirty-one patients were recruited for this study. Their initial diagnosis had been made on average $30.1{\pm}10.1$ years earlier. Score of Berg balance test showed significant correlations with indicators of motor functioning and daily living capacity. Berg balance test score was inversely associated with the unified Parkinson's disease rating scale-motor score, and Schwab and England activities of daily living rating scale. Results : In all 3 correlations, lower scores on the Berg balance test correlated with higher unified Parkinson's disease rating scale-motor scores. Results support the criterion-related validity of the Berg balance test. Conclusion : Our research results agree with other published research in suggesting that the Berg balance test may be used as a screening tool and ongoing assessment tool for patients with Parkinson's disease.

• Journal of Digital Convergence
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• v.17 no.6
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• pp.389-399
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• 2019

The purpose of this study was to investigate the effects of muscle asymmetry of knee joint among elite cyclists on anaerobic pedaling power related capacity. In another word, based on isokinetic strength of Non-Dominant, ND and Dominant, D, side, high, moderate and low ratio of ND to D were classified as High Symmetry Group, Moderate Symmetry Group and Asymmetry Group, respectively. Analysis of muscle asymmetry of extensor's ND and D side might not lead to any difference between the three groups. Based on muscle strength analysis of the flexor's ND and D, there was statistical difference between the groups in ND flexor and in the muscle balance index of the flexor muscle. This result also leads to significant difference in pedaling power functionality, but this effects might not lead to any negative pedaling power. Therefore, among even cyclists who may show almost the same recruitment pattern of ND and D side during pedaling stroke muscle asymmetry could exist but this phenomena might not negatively contribute to the pedaling capacity.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.111-124
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• 2021

Purpose : The purpose of this study is to evaluate whether physical ability is improved by body stabilization, develop training methods to improve physical fitness factors suitable for body conditions, and provide future management and exercise materials to improve Taekwondo athletes' performance, after conducting the Body stabilization exercise (BSE) program on 22 elementary school Taekwondo athletes for 10 weeks to strengthen core muscles and evaluating Visual response speed test (VRST), Functional movement screen (FMS), Y-Balance test (YBT) and Vital capacity (VC). Methods : In order to examine the impact of the BSE program on Taekwondo athletes' VRST, FMS, YBT and VC this study conducted individual evaluations on all subjects, including VRST, FMS, YBT and VC before applying the programs, and compared exercise effects before and after the program, before and after exercise by a certain period. Results : After exercising, strength and quickness were improved significantly and reaction time was significantly shortened (p<.001). The total score of FMS was improved from 10.86±1.17 before to 11.68±0.99 after exercising, was statistically significant (p=.014). YBT was significantly improved from 91.11±4.84 before to 95.68±5.15 after exercising (p<.001). VC improved was statistically significant (p<.001). Conclusion : In conclusion, the BSE athletic program is expected to help Taekwondo athletes perform well by preventing and reducing injuries through the improvement of muscular strength, strength, speed, agility, step, kick, balance, flexibility, full body endurance and the combination of technical abilities.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1556-1566
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• 2020

The purpose of this study was to investigate the effect of Nurida-Ball exercise on isokinetic muscle function, spinal alignment, and dynamic balance capacity in middle-aged men. All middle-aged men(n=16) were divided into 2 groups: Ball exercise(BE, n=8) and control(CON, n=8) group. BE group performed the Nurida-Ball exercise(30 min/day, 3 days/week, 8 weeks) and isokinetic knee and trunk muscle function, spinal alignment, and dynamic balance capacity were measured. All of the measured variables calculated the mean and standard deviation and verified normality using the Shapiro-Wilk test. The independent t-test method and the Paired t-test method were then analyzed to identify differences between groups. This study found that isokinetic knee and trunk muscle function was significantly strengthened in the BE compared with CON group by increasing peak torque(PT) of right and left knee extension(60°/sec, p<0.01, respectively), average power(AP) of right and left knee extension(60°/sec, p<0.05, p<0.01, respectively), and PT of right knee flexion(180°/sec, p<0.05) and AP of right knee extension(180°/sec, p<0.05). In the change of isokinetic trunk muscle function, only PT of trunk extension(180°/sec) was increased in the BE compared with the CON group(p<0.05). In addition, Nurida-ball exercise can improve the spinal alignment by reducing the trunk inclination(p<0.05) in the BE compared with the CON group. Finally, dynamic balance capacity was also enhanced in the BE compared with the CON group by decreasing the score of overall balance index(OBI, p<0.01) and Antero-posterior balance index(p<0.05) in the Stage-6, and OBI(p<0.05) in the Stage-1. This result demonstrated that Nurida-ball exercise may improve spinal alignment, dynamic balance capacity, and isokinetic muscle function, which might be an effective way for the improvement of health-related fitness in middle-aged men.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.9
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• pp.753-760
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• 2006

The purpose of the present work is to investigate the influence of the refrigerant adulteration by LiBr solution on the cooling capacity and COP for three different types of abso게tion chillers: a single-effect type, a series-flow double-effect type and a parallel-flow with double-effect type. A simulation program has been prepared for the cyclic analysis of absorption chillers. With some assumptions, the calculations have been performed by solving the mass balance equation, energy balance equation and the state equation simultaneously. The range of the LiBr concentration of refrigerant was 0% to 20% in the present study. For the single-effect absorption chiller, the maximum decrease in the cooling capacity was 10% at the 20% of LiBr concentration. For the double-effect chiller, the capacity was decreased by 11.1% for the parallel-flow type and the series-flow type. Also, the COP was reduced by 3.0% in single-effect, 2.8% in series-flow type (SR=0.4) and 2.3% in parallel-flow type.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.9
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• pp.424-430
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• 2001

A multi-level optimal power flow(OPF) algorithm has been evolved from a simple two stage optimal Power flow algorithm for constrained power economic dispatch control. In the proposed algorithm, we consider various constraints such as ower balance, generation capacity, transmission line capacity, transmission losses, security equality, and security inequality constraints. The proposed algorithm consists of four stages. At the first stage, we solve the aggregated problem that is the crude classical economic dispatch problem without considering transmission losses. An initial solution is obtained by the aggregation concept in which the solution satisfies the power balance equations and generation capacity constraints. Then, after load flow analysis, the transmission losses of an initial generation setting are matched by the slack bus generator that produces power with the cheapest cost. At the second stage we consider transmission losses. Formulation of the second stage becomes classical economic dispatch problem involving the transmission losses, which are distributed to all generators. Once a feasible solution is obtained from the second stage, transmission capacity and other violations are checked and corrected locally and quickly at the third stage. The fourth stage fine tunes the solution of the third stage to reach a real minimum. The proposed approach speeds up the two stage optimization method to an average gain of 2.99 for IEEE 30, 57, and 118 bus systems and EPRI Scenario systems A through D testings.

• Proceedings of the KIEE Conference
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• 1998.07c
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• pp.926-928
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• 1998

A fast optimization algorithm has been evolved from a simple two stage optimal power flow(OPF) algorithm for constrained power economic dispatch. In the proposed algorithm, we consider various constraints such as power balance, generation capacity, transmission line capacity, transmission losses, security equality, and security inequality constraints. The proposed algorithm consists of four stages. At the first stage, we solve the aggregated problem that is the crude classical economic dispatch problem without considering transmission losses. An initial solution is obtained by the aggregation concept in which the solution satisfies the power balance equations and generation capacity constraints. Then, after load flow analysis, the transmission losses of an initial generation setting are matched by the slack bus generator that produces power with the cheapest cost. At the second stage we consider transmission losses. Formulation of the second stage becomes classical economic dispatch problem involving the transmission losses, which are distributed to all generators. Once a feasible solution is obtained from the second stage, transmission capacity and other violations are checked and corrected locally and quickly at the third stage. The fourth stage fine tunes the solution of the third stage to reach a real minimum. The proposed approach speeds up the coupled LP based OPF method to an average gain of 53.13 for IEEE 30, 57, and 118 bus systems and EPRI Scenario systems A through D testings.

• Proceedings of the SAREK Conference
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• 2006.06a
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• pp.953-958
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• 2006

Perimeter zone has been reinforced by active systems, such as fan-coil units, because it causes an increase in heating and cooling loads, dew condensation in winter, or discomfort with cold-draft to residents in buildings, through poor insulation by light-weighed skin due to progressing multi-storied buildings and skyscrapers. However, because these active systems raise Its capacity so that fossil fuel is used as much as they are added, and ultimately, greenhouse effect is urged, we proposed BIPV system functioned as solar collector which can substitute active system. As an early stage, heat balance equation in steady-state by Fortran was used not only for pre-heating effect and electric power capacity during the day in winter, but also for electric power capacity during day in slimmer and sky radiation effect during night in summer. Especially, we should have considered shading on PV, since even a little bit of it makes the efficiency too low for the PV to work. Still, when the flux of pre-heated air was increased to make air-barrier, its temperature was not enough to make it because the speed of heat exchange was too fast to warm up the air, thus the capacity to meet the condition was evaluated, and electric power from PV was made used for it.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.257-262
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• 2001

A numerical analysis is undertaken to show tile influence of bearing design parameters on tile load capacity of air lubricated spiral grooved thrust bearing. The governing equation derived from the mass balance is solved by the finite difference method. Optimal values for various design parameters are obtained to maximize the load capacity. The design parameters are the groove angle, the groove width ratio, the groove height ratio, arid the seal ratio.

• Korean Journal of Applied Biomechanics
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• v.23 no.1
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• pp.37-43
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• 2013

The purpose of this study was to analyze the 12-week horse riding exercise effect on the locomotion of a body and bilateral balance and flexion/extension of trunk during the sit-to-stand(STS) in elementary and middle school students. One-hundred eleven participants were divided into three groups. Each group was subject to a different horse riding exercise: control group(n = 36), 1 time/week group(n=37), and 3 times/week group(n=38). Two-way repeated ANOVA was used to compare weight transfer time(WTT), trunk flexion velocity(TFV), trunk extension velocity(TEV), mean rising index(MRI), mean weight asymmetry( MWA) among the groups, and STS changes in before and after 12 weeks. There was a group interaction in WTT, TFV, TEV, MRI, and MWA with different responses to horse riding exercise participation. There was a significant increase in 1 time/week group and 3 times/week group of WTT, TFV, TEV, and MRI. Additionally, MWA(an index of a capacity for bilateral balance) in lower extremity was decreased in 3 times/week group. It seems that horse riding exercise positively affected musculoskeletal function of the trunk and lower extremity by accelerating locomotion and bilateral balance.