• The Journal of Korean Physical Therapy
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• v.16 no.1
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• pp.14-31
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• 2004

The Purpose of this study was to investigate the change of lumbar extensor strength according to lumbosacral angle on chronic lumbar back pain patients. For this investigation lumbar extensor strength was administered to 60 patients who were diagnosed chronic lumbar back pain The subjects was to investigate lumbosacral angle in standing position and it were calculated lumbar extensor strength by using Medex. The result of this study summarized are as follows ; 1. Total experimental group exhibited significantly higher difference than control group in lumbar extensor strength among all degree lumbosacral angle. 2. In the relationship between experimental group and control group in lumbar extensor strength among lumbosacral angle, all degree difference was revealed II, I, III order. 3. In the relationship between experimental group and control group in lumbar extensor strength among lumbosacral angle, I group difference was did not. 4. In the relationship between experimental group and control group in lumbar extensor strength among lumbosacral angle, all degree among II group was noted significantly difference except 24, 72 angle. 5. In the relationship between experimental group and control group in lumbar extensor strength among lumbosacral angle, control group was revealed higher muscle strength 48, 60, 72 angle, however no significantly difference was noted 0, 12, 24 angle. The study was objected difference of other group in both of experimental and control group. Because lumbar extensor weakness with bad position was gradually increased back pain, to Maintain normal lumbosacral angle befor exercising lumbar extensor strength was most important.

• Korean Journal of Applied Biomechanics
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• v.24 no.3
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• pp.309-315
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• 2014

The aim of the present study was to investigate the effects of 6-week wrist resistance training on wrist torque control. Nineteen subjects were randomly assigned to either the wrist training group (n=9) or the control group (n=10). The training group performed wrist exercises for six directions (flexion, extension, pronation, supination, radial deviation, and ulnar deviation) while the control group did not. Testing for the isometric torque control error, one-repetition maximum (1-RM) strength, and isokinetic maximum torque (angular velocity of $60^{\circ}/s$ wrist movements) were conducted before and after six weeks of resistance training and after every two-week interval of training. The wrist training group showed significant decreases in isometric torque control error in all six directions after the 2-week resistance training, while the control group did not show significant increase or decrease. The training group showed significant increases in the maximum strength in all six directions assessed by 1-RM strength and isokinetic strength tests after the 4-week resistance training, while the control group did not show any statistically significant changes. This study shows that motor control ability significantly improves within the first two weeks of resistance training, while the wrist strength significantly improves within the first four weeks of resistance training in wrist training group compared to the control.

• Child Health Nursing Research
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• v.25 no.3
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• pp.245-254
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• 2019

Purpose: The purpose of this study was to obtain research-based evidence on the relationships among general characteristics, family strength, self-control, and happiness among late school-aged children using a correlational research design. Methods: The participants were 172 fifth- and sixth-grade students from two public elementary schools. Data were collected by employing structured questionnaires, including the Korean Family Strengths Scale for Strengthening Family II, a self-control scale, and a happiness scale. Data analysis was conducted using SPSS version 23.0. Results: The level of happiness of late school-aged students showed significant correlations with family strength (r=.78, p<.001), and self-control (r=.59, p<.001). Family strength had a significant positive correlation with self-control (r=.55, p<.001). The factors with a significant impact on participants' happiness were family strength (${\beta}=.63$, p<.001), self-control (${\beta}=.21$, p<.001), exercise frequency, and self-perceived health. The total explanatory power of the model was 69%, and the explanatory power of family strength for the level of happiness was 61%, showing that the family strength was the most important factor that promoted happiness in late school-aged students. Conclusion: These findings imply that improving family strength is an important aspect of promoting happiness among late school-aged children. Interventions to strengthen late school-aged children's self-control are also necessary.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.287-290
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• 2000

Nowadays, strength control is performed by test of compressive strength of concrete which is taken in construction filed. But because it is possible to confirm only compressive strength of concrete by that way, it is difficult to performing strength control pr process plan, So, if we can predict compressive strength of concrete, we can decide when shores and forms can be removed safety, plan process efficiently. This study intends to propose basic data for strength control as determination the time of forwoak removal through investigating propriety of strength prediction using Freiesleben function.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.255-298
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• 2003

The purpose of study was to evaluate effects of a trunk muscle strength training on sitting balance of children with spastic cerebral palsy. Five individuals with spastic cerebral palsy(three females. two males; mean aged 6.6) participated three times a week over 6 weeks. Five individuals with spastic cerebral palsy(three females. two males; mean aged 7.0) who did not receive strength training served as control. BPM(Balance Performance Moniter) was used to measured sitting balance and EMG(electromyograph, NORAXON, USA) was used to measured activities of abdominal and erector spine muscle. The obtain result are as follows. 1. The result of this study were following that maximum perturbation area and perturbation velocity were significantly reduced strength training group compared with control group(p<.05). 2. The result of this study were following that maximum perturbation area and perturbation velocity were significantly reduced after strength training compared with pre strength training in strength training group(p<.05). 3. The result of this study were following that maximum perturbation area and perturbation velocity were not significantly reduced at interval of six week in control group(p<.05). 4. The result of this study were following that abdominal muscle activity was significantly increased strength training group compared with control group(p<.05). 5. The result of this study were following that erector spine muscle activity was significantly increased strength training group compared with control group(p<.05). 6. The result of this study were following that abdominal muscle activity and erector spine muscle were significantly increased after strength training compared with pre strength training in strength training group(p<.05). 7. The result of this study were following that abdominal muscle activity and erector spine muscle were not significantly increased at interval of six week in control group(p<.05). In conclusion, the result of this study suggest that improved sitting balance and increased activities of trunk muscle by trunk strength training in spastic cerebral palsy. The result was proposed that therapeutic approach of spastic cerebral palsy with impaired sitting balance should use trunk strength training.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.135-140
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• 2003

As a construction technique is developed recently, the construction space and construction period are considered to important matters. Especially, in case of construction period, several method is proposed for strength control in the construction field. However there are very little strength control models for application of internal condition. The purpose of this study is to develop a strength control model for application of variety internal condition at construction field. The results are as follows ; 1) According to the results of compressive strength of concrete evaluated by logistic curve and proposed curve, proposed curve is applicable of construction field because there is similar relation with logistic curve. 2) It is shown that the construction period is shortened by reduction of the formwork removal time, because a predicted compressive strength of using the new curve is higher than the proposed compressive strength of standard.

• Asia Marketing Journal
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• v.22 no.1
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• pp.27-39
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• 2020

Building on the growing literature on how physical bodily expressions influence psychological processes, the authors propose that exerting physical strength decreases risk perceptions and increases preference for risky options by increasing perceptions of control or agency. The present research is based on the belief of "no pain, no gain", that when an individual exerts physical strength and effort, he believes he can be the agent in bringing about the desired outcome. Because of this automatic association between exerting physical strength and the sense of being in control of the outcome, the authors hypothesize that even in situations where the outcome is determined by chance and luck, individuals exerting effort feel they have more control and thus choose riskier, but more desirable, options. Furthermore, this research clarifies the distinction between physical exertion of strength, high- and low-power poses, and psychological power.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.1
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• pp.58-69
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• 2014

This paper proposes a method for predicting maximum friction coefficients and optimal slip ratios as optimal control parameters for traction control or slip control of autonomous mobile robots on rough terrain. This paper focuses on strength of ground surface which indicates different characteristics depending on material types on surface. Strength of various material types can be estimated by Willoughby sinkage model and by a developed testbed which can measure forces, velocities, and displacements generated by wheel-terrain interaction. Estimated strength is collaborated on building improved Brixius model with friction-slip data from experiments with the testbed over sand and grass material. Improved Brixius model covers widespread material types in outdoor environments on predicting friction-slip characteristics depending on strength of ground surface. Thus, a prediction model for obtaining optimal control parameters is derived by partial differentiation of the improved Brixius model with respect to slip. This prediction model can be applied to autonomous mobile robots and finally gives secure maneuverability on rough terrain. Proposed method is verified by various experiments under similar conditions with the ones for real outdoor robots.

• KIEAE Journal
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• v.7 no.3
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• pp.89-96
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• 2007

The purpose of this experimental study is to investigate the compressive strength, shear strength, bending strength, and crack control by the mixture of the hwang-toh. The size of compressive specimens is $200{\times}200{\times}400(mm)$, and the size of shear, bending specimens is $200{\times}200{\times}600(mm)$. Finally, crack control specimens for comparative comparison is $200{\times}200{\times}15(mm)$. The mixture of the hwang-toh is as follows; Hwangtoh( H)+Water(W), H+W+Sand(S), H+W+S+sTraw(0.5%), H+W+S+sT(1.0%). The actual height, width, and the length are measured at the center of all specimens. The main parameters are mixture ratio of hwang-toh, straw and age of specimens. The test results are as follows. (1) The compressive strength is linearly increased until 15 weeks according to specimen ages. (2) About crack control, the specimen added in 1% straw is the most effective.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.423-428
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• 1994

High strength concrete was placed at the mass concrete slabs, walls, pillars of RC building from August till August. And the construction is going on now. This paper presents mix design, production, quality control and experience with field application of high strength ready-mixed concrete under hot weathered conditions. It is shown to be possible to produce high strength concrete that has 45MPa compressive strength using superplasticizer and cement replaced with 20% fly-ash with appropriate control.