• Journal of the Korea Convergence Society
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• v.8 no.1
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• pp.245-256
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• 2017

The purpose of this study was to determined the converge effects of combined exercise rehabilitation on lower limb muscular function and cytokines in taekwondo player with patellofemoral pain syndrome. In this study, combined exercise rehabilitation(aquatic exercise 3 times a week, resistance exercise 2 times a week) was performed and 20 collegiate taekwondo player with patellofemoral pain syndrome(control group: n=10, combined exercise rehabilitation group: n=10) were participated for 8 weeks. Statistical significance verification was carried out by a two - way ANOVA repeated measures design as a mixture using the SPSS 18.0 program. The statistically significant level was set at 0.05. The results of this study were as following. Peak torque was higher significantly in extensor(p<.001) and flexor(p<.01) at $60^{\circ}/sec$ in the combined exercise rehabilitation group than the control group over combined exercise treatment period. Average power was higher significantly in extensor muscles at $180^{\circ}/sec$ in the combined exercise rehabilitation group than the control group over combined exercise treatment period.(p<.01). The variable of TNF-a was higher significantly in the combined exercise rehabilitation group than the control group as over combined exercise treatment period. Therefore, it can be concluded that a combined exercise rehabilitation program is effective in improving the lower limb muscular function and TNF-a in Patellofemoral Pain Syndrome patient.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.3
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• pp.463-470
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• 2016

A vane shear test (VST) is a simple testing method for determining an undrained shear strength of cohesive soils by minimizing soil disturbance. In this study, the VST was used to determine a shear strength of sand. Dry Nakdong River sand was prepared for loose and dense conditions in a cell and then pressurized with 25, 50, 75 or 100 kPa from the surface of sand. A vane (5 cm in diameter and 10 cm in height) was rotated and a torque was measured within sand. When a torque moment by vane and friction resistance moment by sand is assumed to be equalized, a friction angle can be obtained. When a vane rotates within clay, a uniform undrained shear strength is assumed to be acting on cylindrical failure surface. On the other hand, when it is applied for sand, the failure shape can be assumed to be an octagonal or square column. The relationship between measured torque and resistant force along assumed failure shapes due to friction of sand was derived and the internal friction angle of sand was determined for loose and dense conditions. For the same soil condition, a series of direct shear test was carried out and compared with VST result. The friction angle from VST was between 24-42 degrees for loose sand and 33-53 degrees for dense sand. This is similar to those of direct shear tests.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.6
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• pp.1029-1044
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• 2017

The Discrete Element Method (DEM) is one of the useful numerical methods to analyze the behavior of the ground formation by computing the motion and interaction using particles. The DEM has not been applied in civil engineering but also a wide range of industrial fields, such as chemical engineering, pharmacy, material science, food engineering, etc. In this study, to review a performance of the spoke-type earth pressure balance (EPB) shield TBM (Tunnel Boring Machine), the commercial software based on the DEM technology was used. An analysis of the TBM during excavation was conducted according to two pre-defined excavation conditions with the different rotation speed of a cutterhead. During the analysis, the resistant torque at the face of the cutterhead, the compressive force at the cutterhead and shield surface, the muck discharge at the screw auger were measured and compared. Upon the two kinds of excavation conditions, the applicability of the DEM analysis was reviewed as a modelling method for the TBM.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.3
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• pp.361-366
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• 2012

This paper presents speed control of an electric motorcycle using a fuzzy controller. The electric motorcycle required to meet not only fast throttle response but also stability, when it is on a cruise. However, a 1.5KW (50cc) electric motorcycles selling in the current market are difficult to cruise under the following conditions which are occupant's weight, load weight, wind resistance and road conditions (dirt roads, asphalt road). Because of these reasons, the rapid speed changing occurs in uphill and downhill road. To solve these problems, The input value for Improved fuzzy controller use the speed error and error variance. The output value for improved fuzzy controller uses Q-axis of the motor controlled variable. The D-axis of the motor output for improved fuzzy control uses D-axis controlled variable in proportional to Q-axis controlled variable. Improved fuzzy controller drives the electric motorcycle equipped with IPMSM. The control subject used in this paper is a 1.5KW electric motorcycle equipped with improved fuzzy controller that was used to control the motor speed. To control IPMSM Type of motor torque, D, Q-axis current controller was used. The Fuzzy controller using the proposed algorithm is demonstrated by experimental hardware simulator.

• Elastomers and Composites
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• v.38 no.3
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• pp.227-234
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• 2003

Silicone composites for high voltage insulator (HVI SC) were prepared by adding aluminum trihydrate(ATH) treated by surface treatment agent to base silicone compound at the ratio oi 100:20, 100:40, 100:60, 100:80, and 100:100, respectively And also, ATH was treated by various surface treatment agents, such as stearic arid, acryl silane, and vinyl silane under compounding process. Mechanical properties and electrical properties were investigated for the various contents of ATH and surface-treatment agents. Mechanical properties such as tensile strength, elongation, and tear strength decreased as the load of ATH increased. Volume resistivity, AC break down strength, and tracking resistance for HVI SC containing ATH treated by vinyl silane were better than those for HVI SC containing ATH treated by other surface treatment agents, such as stearic acid and acryl silane. Polymer-filler interaction of silicone composites according to surface treatment agents was studied by measuring bound rubber contend(BR). From the experimental results, BR of silicone composite containing ATH treated with vinyl silane was higher than that of the others. The degree of rule for silicone composite was investigated using Rheometer. Maximum torque of silicone composites contaning ATH treated with vinyl silane was higher than that of silicone composite contaning ATH treated with other surface agents.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.78-86
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• 2019

This paper describes the stiffness optimization of the torsion spring hinge of the large SAR antenna considering the deployment performance. A large SAR antenna is folded in a launch environment and then unfolded when performing a mission in orbit. Under these conditions, it is very important to find the proper stiffness of the torsion spring hinge so that the antenna panels can be deployed with minimal impact in a given time. If the torsion spring stiffness is high, a large impact load at the time of full deployment damages the structure. If it is weak, it cannot guarantee full deployment due to the deployment resistance. A multi-body dynamics analysis model was developed to solve this problem using RecurDyn and the development performance were predicted in terms of: development time, latching force, and torque margin through deployment analysis. In order to find the optimum torsion spring stiffness, the deployment performance was approximated by the response surface method (RSM) and the optimal design was performed to derive the appropriate stiffness value of the rotating springs.

• Journal of Aquaculture
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• v.19 no.4
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• pp.247-253
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• 2006

This study was conducted to investigate the effects of dietary supplementation of ${\beta}-1,3$ glucan on growth and immune responses in juvenile olive flounder, Paralichthys olivaceus fed the white fish meal based diets for 6 weeks. Five experimental diets supplemented with ${\beta}-1,3$ glucan at 0, 0.01, 0.025, 0.05, 0.1 % (Control, $G_{0.01},\;G_{0.025},\;G_{0.05}\;and\;G_{0.1}$, respectively) of diet on a dry-matter basis. Five experimental diets were formulated to be isonitrogenous and isocaloric to contain 50.0% crude protein and 16.7 kJ available energy $g^{-1}$. Fish averaging $3.2{\pm}0.1\;g\;(mean{\pm}SD)$ were randomly distributed in each aquarium as triplicate groups of 15 fish. Weight gain (WG, %), specific growth rate (SGR, %), and feed efficiency (FE, %) of fish fed $G_{0.1}$ diet were found significantly higher than those of fish fed Control, $G_{0.01},\;G_{0.025}\;and\;G_{0.05}$ diets (P<0.05). However, there was no significant difference among the fish fed control, $G_{0.01},\;G_{0.025}$. Chemiluminescent responses (CL) of fish fed $G_{0.1}$ diet were significantly higher than those of fish fed the other diets. Serum lysozyme activities of fish fed $G_{0.05}$ and $G_{0.1}$ diets were higher than those of fish fed control, $G_{0.025}$ and $G_{0.05}$ diets. Fish fed $G_{0.1}$ diet showed a significantly lower cumulative mortality than did fish fed control diet throughout the challenge test (P<0.05). These results suggested that based on growth rate, feed efficiency, non-specific immunity and protection against microbial infections the optimum dietary ${\beta}-1,3$ gulcan could be greater than 0.05% but less than 1.0% in juvenile olive flounder, Paralichthys oilvaceus.

• Journal of Animal Science and Technology
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• v.52 no.4
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• pp.337-346
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• 2010

We report non-specific immune responses and disease resistance against Vibrio anguillarum, Streptococcus iniae and Edwardsiella tarda by dietary supplementation of fermented garlic powder (FGP) in olive flounder for the first time. Four isonitrogenous (45% crude protein) and isocaloric (17.1 MJ/kg) diets were formulated to have 0%, 0.5%, 1% and 2% of the FGP (G-0, G-0.5, G-1 and G-2). The experimental diets were fed to juvenile olive flounder averaging 23.4 g in triplicate groups (90 fish/group) in a flow-through system. After a five-week feeding trial, healthy fish with similar sizes from each tank were selected and injected with 1 ml of three bacteria each to evaluate disease resistance of the fish. During the 5-week feeding trial, the weight gain, specific growth rate, feed conversion ratio, protein efficiency ratio, and survival of the fish were not significantly affected by the experimental diets. However, feed intake was significantly lower (P<0.05) in the fish fed the G-2 diet compared with the control group. Hemoglobin, myeloperoxidase activity, cholesterol and HDL-cholesterol were not different between the dietary groups. However, hematocrit, nitroblue tetrazolium (NBT) activity, and lysozyme activity were increased (P<0.05) with an increment of dietary FGP. Plasma triglyceride of the fish fed the G-0.5 diet was significantly lower than that of fish fed the control diet. The cumulative mortality was lower in the fish fed diets containing FGP compared with the control group in the challenge test except for the bacteria Edwardsiella tarda. The results in this study indicate that dietary supplementation of FGP can enhance the non-specific immune responses and disease resistance of olive flounder against V. anguillarum and S. iniae.

• Journal of Aquaculture
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• v.17 no.1
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• pp.39-45
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• 2004

Three experiments were conducted to determine utilization of Song-Gang(equation omitted) stone as the dietary additive for growth and immune stimulant in juvenile olive flounder. In the feeding trial, four diets were formulated to contain 0, 0.5, 1.0 and 2.0% Song-Gang(equation omitted) stone per kg diet (SGS$_{0}$ , SGS$_{0.5}$, SGS$_{1.0}$ , SGS$_{2.0}$ ). Fish averaging 5.0$\pm$0.04 g (mean$\pm$SD) were fed one of four experimental diets in triplicate groups for 8 weeks. There were no significant differences in weight gain, feed efficiency, protein efficiency ratio, hematosomatic index, condition factor and survival among fish fed all the diets. In chanlenge test, fish were infected by intraperitoneal injection of 0.1 $m\ell$ bacterial suspension with Edwardsielia tarda per fish after the feeding trial. Fish fed SGS$_{0.5}$ diet have a significantly higher cumulative survival rate than did fish fed the other diets (P<0.05). In the anti-mold test, Asprrgiilus niger, Penicillium pinophiltfm, Chaeromium globosum were inoculated with Song-Gang(equation omitted) stone using ASTM G-21 method. The amount of Α. niger, Ρ. pinuphiium. C. globosum didn't increase in Song-Gang(equation omitted) stone for 4 weeks for the test period. Therefore, these results indicate that 0.5% Song-Gang(equation omitted) stone per kg diet could increase immune resistance in juvenile olive flounder and Song-Gang(equation omitted) stone could be used as the anti-mold additive in fish feed.

• The korean journal of orthodontics
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• v.34 no.5 s.106
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• pp.417-428
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• 2004

The purpose of this study was to evaluate the stress distributions at the periodontal ligament (PDL) and displacements of the maxillary first molar when mesially directed force was applied under various molar angulations and rotations. A three dimensional finite element model of the maxiilary first molar and its periodontal ligament was made Upright position, mesially angulated position by $20^{\circ}$ and distally angulated position of the same degree were simulated to investigate the effect of molar angulation. An anteriorly directed force of 200g countertipping moment of 1,800gm-mm (9:1 moment/force ratio) and counterrotation moment of 1,000gm-mm (5:1 moment/force ratio) were applied in each situation. To evaluate the effect of molar rotation on the stress distribution, mesial-in rotation by $20^{\circ}$ and the same amount of distal-in rotation were simulated. The same force and moments were applied in each situation. The results were as follows: In all situations, there was no significant difference in mesially directed tooth displacement Also, any differences in stress distributions could not be found, in other words. there were no different mesial movements. Stress distributions and tooth displacement of the $20^{\circ}$ mesially angulated situation were very similar with those of the $20^{\circ}$ distal-in rotated situation. The same phenomenon was obserned between the $20^{\circ}$ distally angulated situation and $20^{\circ}$ mesial-in rotated situation. When the tooth was mesially angulated, or distal-in rotated, mesially directed force made the tooth rotate in the coronal plane. with its roots moving buccally, and its crown moving lingually. When the tooth was distally angulated, or mesial-in rotated, mesially directed force made the tooth rotate in the coronal plane, with its roots moving lingually and its crown moving buccally. When force is applied to au angulated or rotated molar, the orthodontist should understand that additional torque control is needed to prevent unwanted tooth rotation in the coronal plane.