• The Journal of Korean Physical Therapy
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• v.14 no.4
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• pp.260-265
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• 2002

There are many methods for muscle strengthening. Muscle strengthening with eccentric contraction work is the best way by researcher's report. Also, eccentric contraction need proper resistance for muscle strengthening. Combination of isotonic in PNF is a muscle strengthening method with manual resistance. It makes concentric contraction $\rightarrow$ eccentric contraction $\rightarrow$ concentric contraction with continually and without muscle relaxation. Combination isotonic technique use with PNF pattern. Therefore, it will make development and increasing of active control motion, coordination, actual range of motion, strengthen and functional training in eccentric control of movement. Concentric contraction have the 3rd lever system and eccentric contraction have the 2nd lever system with combination of isotonic. Serial concentric contraction $\rightarrow$ eccentric contraction $\rightarrow$ concentric contraction make strong SEC and PEC. It will be increase elasticity of SEC, PEC and contractile components either.

• The Journal of Korean Physical Therapy
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• v.15 no.2
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• pp.168-181
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• 2003

The purpose of this study was to investigate the effects of circuit weight training(CWT) on isokinetic muscle strength and body composition in elderly. The subjects who engaged in this experiment exercised at 40$\%$ of 1-RM, 12 repetitions, followed by 15 sec as the subject moved to the each break training program which was consist of the circuit of 10 stations performed on 3 set a day, circuits 3 days a week during 10 weeks. The assessment of isokinetic factor was in concentric flexors and extensors of right and left knee joint. Tests were performed on the Cybex 770 Isokinetic Dynamometer and body composition were estimated the three parts of chest, abdomen and anterior thigh by using skinfold caliper, calculated the average and followed by Seri and Brozek way. Statistical analysis were performed using analysis of variance paired t-test, accepting level for all significant was above $\alpha$=.05 and $\alpha$=.01. Following is as a result of 10 weeks circuit weight training. 1. At the $60_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly (p < .01). 2. At the $180_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly (p < .01). 3. At the $60_{\circ}$ /sec, the right and left knee isokenetic concentric flexors and extensors average power increased significantly(p < 0.5, p < .01) and at the $180_{\circ}$ /sec, the right extensors didn't show any statistical significant. 4. At the $60_{\circ}$ /sec, the right and left knee Isokinetic concentric flexors and extensors total work increased significantly(p < .05, p < .01) but at the $180_{\circ}$ /su right concentric flexors didn't show any statistical significant. 5. The body composition changed significantly(p < .01). These results suggest that 10 weeks circuit weight training increases the peak torque, average power, total work significantly and decreases the $\%$body fat significantly.

• The Journal of Korean Physical Therapy
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• v.15 no.4
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• pp.398-411
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• 2003

The purpose of this study was to investigate the effects of circuit weight training(CWT) on isokinetic muscle strength and body composition in elderly. The subjects who engaged in this experiment exercised at $40\%$ of 1-RM, 12 repetitions, followed by 15 sec as the subject moved to the each break training program which was consist of the circuit of 10 stations performed on 3 set a day, circuits 3 days a week during 10 weeks. The assessment of isokinetic factor was in concentric flexors and extensors of right and left knee joint. Tests were performed on the Cybex 770 Isokinetic Dynamometer and body composition were estimated the three parts of chest, abdomen and anterior thigh by using skinfold caliper, calculated the average and followed by Seri and Brozek way. Statistical analysis were performed using analysis of variance paired t-test, accepting level for all significant was above ${\alpha}=.05$ and ${\alpha}=.01$. Following is as a result of 10 weeks circuit weight training. 1. At the $60_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly(p<.01). 2. At the $180_{\circ}$ /sec, the right and left knee isokinetic concentric flexors and extensors peak torque increased significantly(p<.01). 3. At the $60_{\circ}$ /sec, the right and left knee isokenetic concentric flexors and extensors average power increased significantly(p<.05, p<.01) and at the $180_{\circ}$ /sec, the right extensors didn't show any statistical significant. 4. At the $60_{\circ}$ /sec, the right and left knee Isokinetic concentric flexors and extensors total work increased significantly(p<.05, p<.01) but at the $180_{\circ}$ /sec right concentric flexors didn't show any statistical significant. 5. The body composition changed significantly(p<.01). These results suggest that 10 weeks circuit weight training increases the peak torque, average power, total work significantly and decreases the $\%$body fat significantly.

• Korean Journal of Applied Biomechanics
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• v.23 no.2
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• pp.159-167
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• 2013

The purpose of this study was to evaluate the gender differences on gait pattern and the kinetics on lower extremities according to the different gait speed. Ten collegiate male students (age : $23.80{\pm}2.94$ yrs, height : $179.40{\pm}5.04$ cm, weight : $66.57{\pm}5.64$ kg) and ten female students (age : $23.40{\pm}2.91$ yrs, height : $166.06{\pm}5.61$ cm, weight : $53.76{\pm}2.75$ kg) participated in this study. To investigate the role, the ratio of the use, and the effectiveness of each joint during gait, we examined the joint work and the contribution to total work. The results of this study were as follows: First, gait pattern was not differ between male and female, hip joint ROM increased with the increase of gait speed both male and female. Second, the eccentric work of the ankle joint decreased with the increase of the gait speed both male and female, on the other hand increased on the knee joint. Third, in the result of the contribution to total eccentric work, male in both the two gait speed was the biggest on the hips joint. However, female in normal gait speed was the greatest on the ankle joint, was the most on the knee joint in the fast gait speed. Forth, the concentric work on the ankle and hip joint increased with the increase of gait speed both male and female. Fifth, in the result of the contribution to total concentric work, there is no difference in the male both the two gait speed, however decreased in the female on the knee joint with the increase of the gait speed, on the other hand increased on the ankle joint.

• Physical Therapy Korea
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• v.12 no.3
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• pp.94-100
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• 2005

Eccentric muscle contraction is more effective than concentric and iosmetric muscle contraction in increasing muscle strength. Also, eccentric or concentric-eccentric training has greater effective in neural activation and muscle hypertrophy than concentric training. In some study, eccentric exercises have been shown to reduce pain and improve function on Achilles tendinopathy. The purpose of this study was to evaluate the effect of eccentric isokinetic exercise in a patient with dislocation of the tarsometatarsal joint by traffic accident. After eccentric isokinetic training, peak torque, average work, and average power were increased. Also, the patient was fully weightbearing with a pain free normal gait thus making good recovery.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.379-382
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• 2001

In the muffler industry, the main purpose of the research works is to determine a way to increase the TL (Transmission Loss) properties of the muffler, without deteriorating the back pressure influence. In order to obtain better results, several works have been done by changing the geometrical characteristics of the muffler or the type of the muffler. This work will focus on the perforated muffler components with concentric chamber, to investigate the effect of a non-uniform porosity along the inner perforated tube of the muffler on the TL. It is noted that varying the perforation ratio affects the peaks frequencies of the TL, especially fer $2\pi < kL < 4\pi$ (in the case of L : 200mm for the concentric resonator). The magnitudes of the TL, for this range of frequencies, vary noticeably by changing the porosity distribution.

• Structural Engineering and Mechanics
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• v.61 no.2
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• pp.231-244
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• 2017

The aim of this study is to develop a semi-analytical method to investigate fluid-structure coupling of concentric double shells with different lengths and elastic behaviours. Co-axial shells constitute a cylindrical circular container and a baffle submerged inside the stored fluid. The container shell is made of functionally graded materials with mechanical properties changing through its thickness continuously. The baffle made of steel is fixed along its top edge and submerged inside fluid such that its lower edge freely moves. The developed approach is verified using a commercial finite element computer code. Although the model is presented for a specific case in the present work, it can be generalized to investigate coupling of shell-plate structures via fluid. It is shown that the coupling between concentric shells occurs only when they vibrate in a same circumferential mode number, n. It is also revealed that the normalized vibration amplitude of the inner shell is about the same as that of the outer shell, for narrower radial gaps. Moreover, the natural frequencies of the fluid-coupled system gradually decrease and converge to the certain values as the gradient index increases.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.3
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• pp.97-104
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• 2000

Studies on the principle of traditional moulding techniques of architecture or structure are very important in the point of the work could accomplish succession to modern design. As an attempt of these work, this study tried to examine traditional moulding techniques applied in planes of ancient architecture and structure closely. The major findings of this study are summarized as follows; It was verified that planes of ancient Korean architectures and structures analyzed in this study was moulded by its multiple partitions with the six or eight partitions of circumference as the fundamental form. The well unearthed in kyong-bok palace recently was moulded by a concentric circle assumed form of 4 circle which was extended with equal interval and divided into multiple of 8 partition of circumference. Chon-duk-jung in chang-duk palace also was moulded by a concentric circle assumed form of 3 circle extended with equal interval, but circle were divide by 6 partitions. It was also found that 6$^{\circ}$§8 partitions of circumference(or its multiple partition) was applied to not only above structures but also the moulding planes of ancient architecture, and as a results, figures revealed in architectures analyzed is classified into three classes. And, this study analyzed arrangements of two temples. As a results, it is discovered that the Grid used in moulding planes of each building fixed the arrangement of buildings. Therefore, moulding by equal partition of circumference decided the form of each building and the relation of element at the same time.

• Advances in concrete construction
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• v.16 no.1
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• pp.21-34
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• 2023

This work presents a complete optimal model for trapezoidal combined footings that support a concentric load and moments around of the "X" and "Y" axes in each column to obtain the minimum area and the minimum cost. The model presented in this article considers a pressure diagram that has a linear variation (real pressure) and the equations are not limited to some cases. The classic model takes into account a concentric load and the moment around of the "X" axis (transverse axis) that is applied due to each column, i.e., the resultant force is located at the geometric center of the footing on the "Y" axis (longitudinal axis), and when the concentric load and moments around of the "X" and "Y" axes act on the footing is considered the uniform pressure applied on the contact surface of the footing, and it is the maximum pressure. Four numerical problems are presented to find the optimal design of a trapezoidal combined footing under a concentric load and moments around of the "X" and "Y" axes due to the columns: Case 1 not limited in the direction of the Y axis; Case 2 limited in the direction of the Y axis in column 1; Case 3 limited in the direction of the Y axis in column 2; Case 4 limited in the direction of the Y axis in columns 1 an 2. The complete optimal design in terms of cost optimization for the trapezoidal combined footings can be used for the rectangular combined footings considering the uniform width of the footing in the transversal direction, and also for different reinforced concrete design codes, simply by modifying the resisting capacity equations for moment, for bending shear, and for the punching shear, according to each of the codes.

• Journal of the korean Society of Automotive Engineers
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• v.14 no.3
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• pp.109-114
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• 1992

The purpose of this study is to experimentally research the effects of polymer additives on turbulent transition of Couette flow between concentric cylinders when outer one is rotating and inner one is at rest; the diameter ratio being 0.2. Aqueous polymer solution generate the degradation phenomena in machine forming work, but this is not effected in about 10 minute at 5ppm. aqueous polymer solution testing. The Reynolds number, referred to the gap distance and rotation velocity of the outer cylinder, of turbulent transition is about 20000 for water flow. In the laminer region, the torque value is as same as theoretical one in the region of low Reynolds number, but becomes high with an increase in the Reynolds number. The polymer additives reduce the Reynolds number for turbulent transtition. In the turbulent region, the torque is remarkably reduced by the polymer additives, soluble polymer take down effect of turbulent transition boundary torque.