• Title/Summary/Keyword: Physical Experiments

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The Effect of Muscle Strength, Endurance & Flexibility on Taping and Concentric Exercise of Trunk (테이핑과 체간의 구심성 운동이 근력, 지구력 및 유연성에 미치는 영향)

  • Cho, Nam-Jung;Choi, Won-Jye;Park, Sun-Ha;Park, Hyun-Ju;Oh, Sang-Bu;Oh, Han-Suk;Ham, Jeong-Dae;Yoo, Byung-Kook;Lee, Sam-Cheol;Son, Kyung-Hyun
    • Journal of Korean Physical Therapy Science
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    • v.16 no.3
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    • pp.35-42
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    • 2009
  • Background: The purpose of this study is to measure the amount of influence of taping and a whole body balance upon muscle strength, endurance, and flexibility. Experiments were conducted by two different groups, specially designed for this study. The choice of exercise methods for each group depends on its own idiosyncratic characteristics (or Each group employs its own idiosyncratic exercise method). Methods: The first group, with taping applied, undertook exercises three times a week; second group just took exercises three times a week. These experiments show the following outcomes. Results: The first group showed a considerable amount of difference in terms of muscle strength, endurance, and flexibility. Second group also showed similar outcome. Both the first group and the second group revealed a considerable difference. But the first group showed a bigger difference than the second group. Conclusion: Thus, the result of these experiments strongly indicates that exercise, with taping applied, turns out the most effective in promoting muscle strength, endurance, and flexibility.

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Studies on the Physical Properties and Application of EPDM-Polymer Blends. Part 2. Physical Properties for EPDM-SBR Blends (EPDM과 각종(各種) Polymer의 Blend에 의(依)한 성능변화(性能變化) 및 그 응용(應用)에 관(關)한 연구(硏究) (제2보(第2報)) EPDM과 Butadiene-Styrene Rubber의 Blend에 대(對)하여)

  • Kim, Joon-Soo
    • Elastomers and Composites
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    • v.6 no.2
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    • pp.73-79
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    • 1971
  • As a series of the studies of EPDM-Polymer blends, the experiments are concentrated to the investigation of the physical properties of the EPDM-SBR blends. The results are shown as follows: 1. Tensile strength decreased with increase in EPDM contents and the decreasing value was good results than NR blending. 2. It was found that the aging were much improved after blending and experiments data was good results than NR blending.

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The comparison of muscle activity according to various conditions during smartphone use in healthy adults

  • Kim, You Lim;Yoo, Jaehyun;Kang, Sinwoo;Kim, Taerim;Kim, Namyeol;Hong, Sojeong;Hwang, Wonjeong;Lee, Suk Min
    • Physical Therapy Rehabilitation Science
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    • v.5 no.1
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    • pp.15-21
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    • 2016
  • Objective: The purpose of this study was to see the changes in muscle activity of the upper limb in persons using a smartphone. Design: Cross-sectional study. Methods: An experiment was conducted to target 15 right-handed university students. Experiments were carried out for students using cell phones for more than a year. In this study, experiments were carried out with one-handed and both handed operation of smartphone use in a sitting position, the same parameters with smartphone use in a standing position. The experiments were carried out by having the subjects write a text message in Korean on the smartphone for 3 minutes repeated 3 times with a rest period of 10 seconds given between each 3 minute period. Electromyography (EMG) was used to record the muscle activity of the upper trapezius (UT), extensor carpi radialis (ECR), and abductor pollicis (AP) during phone operation. Results: The muscle activity of the AP and ECR were significantly higher during single handed compared to double handed in both sitting and standing position (p<0.05). The muscle activity of the ECR was significantly higher in standing position compared to sitting position with double handed use of the smartphone (p<0.05). UT muscle activity of the right has been activated more than twice compared to the left UT in a sitting position (p<0.05). And UT muscle activity on the right has been activated more than five times compared to the left in a standing position (p<0.05). Conclusions: Using smartphone with double hand is useful for the prevention of musculoskeletal disorders.

개별요소법을 이용한 핵석층의 물성 산정 : 화강암질 편마암 지역에 분포하는 핵석층의 예

  • Yu, Seung-Hak;Park, Yeong-Do;Kim, Gi-Seok;Park, Hyeon-Ik;Seo, Yeong-Ho;Park, Yeon-Jun
    • Proceedings of the Korean Society for Rock Mechanics Conference
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    • 2007.03a
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    • pp.130-139
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    • 2007
  • We have carried out numerical compression experiments to estimate the mechanical properties (Mohr-Coulomb and elastic) of corestone-bearing saprolites in Beolgyo area. The studied saprolite, consisting of mechanically much stronger corestone and weaker matrix, is a weathering product of the Precambrian granitic gneiss in the Youngnam massif. Since the saprolite consists of larger corestones with diameter up to 2m, it is impossible to directly measure the mechanical properties by physical experiments. We have measured the mechanical properties of corestone and matrix from naturally occurring saprolite and have used them as a reference for our numerical model. Then, we mixed each material and carried out biaxial compression tests while varying the volume percentage of corestones from 0 to 57%. We found that both cohesion and internal friction angle increase with the volume percentage of corestones while elastic modulus remains constant. We found the results from numerical experiments are in contradiction to what is known from physical experiments using artificial saprolites. This may be due to a possibility that the sharp and discrete nature of interface between corestone and matrix in physical experiments differs from the gradual interfacial nature in numerical modelling and natural saprolites.

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Evaluation of reactor pulse experiments

  • I. Svajger;D. Calic;A. Pungercic;A. Trkov;L. Snoj
    • Nuclear Engineering and Technology
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    • v.56 no.4
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    • pp.1165-1203
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    • 2024
  • In the paper we validate theoretical models of the pulse against experimental data from the Jozef Stefan Institute TRIGA Mark II research reactor. Data from all pulse experiments since 1991 have been collected, analysed and are publicly available. This paper summarizes the validation study, which is focused on the comparison between experimental values, theoretical predictions (Fuchs-Hansen and Nordheim-Fuchs models) and calculation using computational program Improved Pulse Model. The results show that the theoretical models predicts higher maximum power but lower total released energy, full width at half maximum and the time when the maximum power is reached is shorter, compared to Improved Pulse Model. We evaluate the uncertainties in pulse physical parameters (maximum power, total released energy and full width at half maximum) due to uncertainties in reactor physical parameters (inserted reactivity, delayed neutron fraction, prompt neutron lifetime and effective temperature reactivity coefficient of fuel). It is found that taking into account overestimated correlation of reactor physical parameters does not significantly affect the estimated uncertainties of pulse physical parameters. The relative uncertainties of pulse physical parameters decrease with increasing inserted reactivity. If all reactor physical parameters feature an uncorrelated uncertainty of 10 % the estimated total uncertainty in peak pulse power at 3 $ inserted reactivity is 59 %, where significant contributions come from uncertainties in prompt neutron lifetime and effective temperature reactivity coefficient of fuel. In addition we analyse contribution of two physical mechanisms (Doppler broadening of resonances and neutron spectrum shift) that contribute to the temperature reactivity coefficient of fuel. The Doppler effect contributes around 30 %-15 % while the rest is due to the thermal spectrum hardening for a temperature range between 300 K and 800 K.

The Effects of Weight-Bearing Exercise on Upper Extremity Activities Performance in the Female Stroke Patients

  • Lee, SungEun;Cho, SungHyoun;Kim, Kyoung
    • International Journal of Contents
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    • v.9 no.1
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    • pp.65-70
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    • 2013
  • The purpose in the present study was to examine the effects of weight-bearing exercises on stroke patients' ability to perform upper extremity activities. Experiments were conducted with 24 female stroke patients who were randomly assigned to either a control group (CG) that performed general exercise or an experimental group that performed weight-bearing exercise (WBG). The experiments were conducted for 30 minutes per time, three times per week for six weeks. The upper extremity functions, grasping power, and the ability to manipulate the fingers were measured for both groups before the experiments and again six weeks after the beginning of the experiments. Although the scores for upper extremity functions relating to raising the arms that correspond to proximal upper extremity functions increased in both groups, the WBG showed more significant improvement. The WBG showed significant changes in grasping power compared to the CG. Based on these results, weight-bearing exercise can be effective in improving the ability to perform upper extremity movements and grasping power and thus can be used in stroke rehabilitation.

Physical Experiments and Computer Simulations for Large Deformation Problems (대변형문제의 컴퓨터 시뮬레이션과 실험)

  • Yoo, Wan-Suk;Dmitrochenko, Oleg;Park, Su-Jin;Moon, Sang-Hyuk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.644-647
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    • 2005
  • In this paper, computer simulations with the absolute nodal coordinate formulation for large deformation problems in flexible multibody dynamics are compared to the real experiments. A high speed camera was employed to capture the deformed shapes of a thin beam, a plate, a rotating chain, and a paper strip. The measured data was used to calculate precise values for stiffness and damping ratio of the objects. Also a rotating strip and a helicoseir problem were formulated for computer simulation, and the computational results are also compared to the experiments.

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Measurement and Interpretation of Undergraduate Students' Writing about the Experiments of the Photoelectric Effect

  • Jho, Hunkoog;Ji, Youngrae
    • New Physics: Sae Mulli
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    • v.68 no.11
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    • pp.1231-1239
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    • 2018
  • This study aimed at examining undergraduate students' writing about experiments related to the photoelectric effect and giving some implications for experiment education. Thus, this study analyzed 26 students' reports about three kinds of experiments: measuring Planck's constant, comparing the photocurrent and the photovoltage across the intensity of light, and comparing the photocurrent and the photovoltage across the frequency of light. In the measurements, less than 25% of the students expressed the data to the correct number of significant figures even though two-thirds of the students successfully obtained the data given in the manual. In terms of interpretation, the students were not aware of the physical meanings of the detailed parts in the graphs. Even though over 50% of the students drew a line relating photocurrent to voltage, no students compared the theoretical to the empirical data or made a judgment as to whether of not the background theory really fit the experiment. The research findings showed that insufficient knowledge and skills for physics inquiry may be an obstacle in performing the experiments well.

Effects of Background Depth Information on the Judgment of Two-dimensional Shapes (배경 깊이정보가 이차원 자극의 형태 판단에 미치는 영향)

  • Kim, Young-Geun;Shin, Hyun-Jung
    • Korean Journal of Cognitive Science
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    • v.17 no.4
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    • pp.287-301
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    • 2006
  • Two experiments were performed to investigate effects of background depth information on the judgment of two-dimensional shapes, using the Posner et al.'s(1969) physical match task. In both experiments, the focus was on whether the background depth information affects the decisions of physical shape sameness of two letters or figures presented successively. In Experiment 1, artificially constructed rues of linear perspective and texture gradient were used, whereas cues contained in a real road situation were used in Experiment 2. The results of both experiments showed that the depth cues affect the perception of two-dimensional shapes. That is, when two stimuli of the same physical shape were likely to be perceived differently due to the given depth cues, response accuracies('yet' in this case) decreased and reaction tines of physical match increased. And when two stimuli of the different physical shape were likely to be perceived the same due to the given depth cues, response accuracies('no' in this case) decreased and reaction times of physical match increased likewise. These results wert discussed in terms of some conceptual methodological problems of the previous studies on the shape constancy and the directions of future research.

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The Effects of Hot and Cold Therapy on Vital Sign and Blood Components (${\cdot}$ 냉 적용이 Vital sign 및 혈액 성분에 미치는 영향)

  • Park, Kyu-Hyun;Jun, Kyong-Hee;Park, Rae-Joon
    • The Journal of Korean Physical Therapy
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    • v.13 no.2
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    • pp.313-324
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    • 2001
  • The 15 male students of T-college which is located in Taegu, who don't have any cardiovascular diseases and skin diseases and agreed to the experiment for finding out the effects of hot and cold therapy. They were divided 5 experimental groups, that is hot therapy in blood Pressures, hot therapy group showed significantly difference of systolic blood Pressure. And the hot therapy group and hot and cold therapy showed the distinctive differences in Scheffes' s analysis after the fact. 3. There was no significant difference in pulsation between before and after experiment and there were no differences in each group. 4. The hot therapy group showed significant difference in WBC and didn't show any difference in RBC(p<.05). 5. Timing does not effect to each group in the changes of HGB and HCT. 6. In the comparison between before and after the experiments in the changes of MCV, cold therapy group showed significant measurement. And in the comparison between before and after one hour the experiment in the changes of MCV, cold therapy group showed significant measurement. The experimental group 1 and 3 showed the distinctive differences in Scheffe' s analysis after the fact(p<.05). 7. In the comparison between before and after one hour experiments in MCV changes, the cold therapy group had significant differences(p<.05). 8. There were no significant differences between before and after the experiments in MCHC changes. 9. In the comparison between before and after one hour experiments in PLT changes, cold therapy group had significant changes(p<.05) and there were no differences among three group.

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