• The Journal of Korean Physical Therapy
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• v.11 no.1
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• pp.111-119
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• 1999

The object of study who healthufl thirty persons have been enforced Isokinetic exercise of non-dominant muscular strength. The next same that each dominant muscular strength and non-dominant strength, peak torque and total work have been comparative analysis 1, Shoulder muscles comparion increase peak torque at low speed from pretraining Isokinetic exercise of non-dominant strength side to ten week of post-training.. Flexor and extensor come out high and statistically significant 6, 8, 10 week than pretraining. Adductor and abductor come out high and statistically significant 4, 6, 8. 10 week then pre-training, Internal rotator and external rotator come out statistically significant 2, 4, 6, 8, 10 week then pre-ttraining. 2. Shoulder muscles comparion increase peak torque at high speed from pre-training Isokinetic execise of non-dominant strenght side to ten week of post-training. Flexor and extensor come out high and statistically significant 4, 6, 8, 10 week then pie-training. Adductor and abductor come out high and statistically significant 2, 4, 6, 8, 10 week than pre-training. Futernal rotator and external rotator come out statistically significant 4. 6, 8, 10 week than pre-training.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.735-749
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• 2001

The purpose of this study was to compare the flexibility and isokinetic differences between normal dancers and dancers with chronically sprained ankle. For the experiment Eversion/Inversion testing was performed by a Cybex 770 isokinetic dynamometer at the a speeds of 30$^{\circ}$ /sec and 120$^{\circ}$ /sec on each 7 subject group. The results were; 1) No differences were found between the two groups in ROM of ankle, but ROM of eversion has 2.8$^{\circ}$ higher in the injury group than the normal group. 2) Differences were found between the two groups in peak torque. average power, total work at the evertor and invertor in injury side.(30$^{\circ}$ /sec) 3) Differences were found between the two groups in peak torque at the evertor and invertor in normal side.(30$^{\circ}$ /sec) 4) Differences were found between the two groups in total work at the evertor in normal side. (30$^{\circ}$ /sec) 5) Differences were found between the two groups in peak torque, total work at the evertor and invertor in injury side. (120$^{\circ}$ /sec)

• The Journal of Korean Physical Therapy
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• v.12 no.1
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• pp.9-13
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• 2000

The purpose of this study was to determine the overflow effect and cross training effect of isometric quadriceps training that performed in specific angle of unilateral let. Ten healthy students with an average age of 24 years$(24.1\pm1.3)$, were participated in this study. Then 5 subjects in each group were chosen at random to train using only right quadriceps muscle two time per day(group 2), five times a week and the other 5 subjects(group 1) were chosen to train one times per day, five times a week for 2 weeks at only 50 degrees (contract 6 seconds, rest 10 seconds, 3 sets). Before and after the training, isometric quadriceps muscle testing of the both leg was Performed at three different angles, 60, 50 and 40 degrees respectively by BHN-COM (isokinetic dynamometer) in sitting position. The data was analyzed with paired t-test to determine significant difference between before and after training. In this study, we have found that the isometric quadriceps muscle training on specific angle of right side produced overflow effect In healthy subjects. However, increasing the peak torque of specific angle(training angle) of trained limb did not have an effect on increasing the peak torque of contralateral limb. These results demonstrate that the cross training effect did nut found in this study but a alight increase of peak torque of the untrained limb would recognized the possibility of cross training effect.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.1
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• pp.11-24
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• 2017

The present work focuses multi-objective optimization of blade sweep for a Wells turbine. The blade-sweep parameters at the mid and the tip sections are selected as design variables. The peak-torque coefficient and the corresponding efficiency are the objective functions, which are maximized. The numerical analysis has been carried out by solving 3D RANS equations based on k-w SST turbulence model. Nine design points are selected within a design space and the simulations are run. Based on the computational results, surrogate-based weighted average models are constructed and the population based multi-objective evolutionary algorithm gave Pareto optimal solutions. The peak-torque coefficient and the corresponding efficiency are enhanced, and the results are analysed using CFD simulations. Two extreme designs in the Pareto solutions show that the peak-torque-coefficient is increased by 28.28% and the corresponding efficiency is decreased by 13.5%. A detailed flow analysis shows the separation phenomena change the turbine performance.

• Journal of Power Electronics
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• v.14 no.2
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• pp.341-350
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• 2014

The torque ripple of switched reluctance motors (SRMs) is the main disadvantage that limits the industrial application of these motors. Although several methods for smooth-toque operation (STO) have been proposed, STO works well only within a certain torque and speed range because of the constraints of the supply voltage and peak current. Based on previous work that sought to expand the STO range, a scheme is developed in this study to determine the maximum smooth torque range at each speed. The relationship between the maximum smooth torque and speed is defined as the smooth torque speed characteristics (STSC), a concept similar to torque speed characteristics (TSC). STSC can be utilized to evaluate torque utilization by comparing it with TSC. Thus, the concept benefits the special design of SRMs, especially for the generation of smooth torque. Furthermore, the torque sharing function (TSF) derived from the proposed method can be applied to STO, which produces a higher smooth torque over a wider speed range in contrast to four typical TSFs. TSimulation and experimental results verify the proposed method.

• Journal of Power Electronics
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• v.14 no.2
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• pp.351-361
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• 2014

The discrete torque generation mechanism and inherently nonlinear magnetic characterization of switched reluctance motors lead to unacceptable torque ripples and limit the application of these motors. In this study, a phase current profiling technique and torque sharing function are proposed in consideration of magnetic saturation effects and by minimizing power loss in the commutation area between the adjacent phases. Constant torque trajectories are considered in incoming and outgoing phase current planes based on nonlinear T-i-theta curves obtained from experimental measurements. Optimum points on constant torque trajectories are selected by improving drive efficiency and minimizing copper loss in each rotor position. A novel analytic invertible function is introduced to express phase torque based on rotor position and its corresponding phase current. The optimization problem is solved by the proposed torque function, and optimum torque sharing functions are derived. A modification method is also introduced to enhance the torque ripple-free region based on simple logic rules. Compared with conventional torque sharing functions, the resultant reference current from the proposed method has less peak and effective values and exhibits lower copper loss. Experimental and simulation results from a four-phase 4 KW 8/6 SRM validate the effectiveness of the proposed method.

• The Journal of Korean Physical Therapy
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• v.13 no.3
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• pp.537-549
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• 2001

The isometric torque of the elbow flexor and extensor muscles were measured for 6 seconds at a joint angle of 90$^{\circ}$ , in 10 normal subjects (control group) and 10 hemiplegic subjects(patient group), using the Cybex NORMTM System. The peak torque, the time to peak torque were measured for each exercise. In addition, heart rate and blood pressure were recorded simultaneously at rest and immediately following exercise completion at 1 and 3m mutes. Statistical analysis was performed using SPSS 8.0 for Windows software and mean and standard deviations were calculated. The results are as follows. 1) In the patient involved group. the isometric values for flexors and extensors were significantly lower than in the normal nondominant group(p<.05). 2) The extensor to flexor strength ratio in the isometric mode was 121.0% in the patient involved group compared with 78.7%in the normal nondominant group, a significant difference(p<.05). 3) The mean increment ratio was increased 19.0% for systolic blood pressure and 25.2% for disatolic blood pressure in the patient group. 4) The mean increment ratio was increased 36.0% heart rate in the patient group.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.8
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• pp.389-395
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• 2006

In the single-phase switched reluctance motor (SRM) drive, the required DC source is generally supplied by the circuit consisting of bridge rectifier with diodes and many filter capacitances connected with AC source. Although the peak torque ripple of SRM is small because of large capacity of the capacitance, the charge and discharge time swhich the AC source acts on the capacitance are small and the peak current will pass on the side of source, so power factor and system efficiency decrease. Therefore a novel SRM drive system is presented in this paper, which includes drive circuit realizing reduction of torque ripple and improvement of power factor and switching topology. The proposed drive circuit consists of one switching part and diodes which can separate the output of AC/DC rectifier from the large capacitance and supply power to SRM alternately in order to realize reduction of torque ripple and improvement of power factor through the turn on and turn off of switching part. In addition, the validity of method is tested by simulation and experiment.

• The Journal of Korean Physical Therapy
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• v.13 no.2
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• pp.325-333
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• 2001

The purpose of this study was to find out the effects of hallux valgus on the ankle plantarflexor and dorsiflexor peak torque, on the total work, on the average power, and on the Peak torque of plantarflexor to dorsiflexor ratio values. Isokinetic ankle plantarflexor and dorsiflexor strength was evaluated in 30 women(control: 15, hallux valgus: 15) by Cybex NORM System. Test data was gathered in the right ankle at a speed of 60/sec, 90/sec, 120/sec in the control group and the hallux valgus group. Statistical analysis was performed using SPSS 10.0 for windows software. Mean and standard deviations were measured and calculated for the General characterristic of subjects. A paired t-test was used to examine the differnces in the means for the ankle plantarflexor and dorsiflexor between two groups. Pearson coefficient correlation was used to examine the correlation of the hallux valgus and the peak torque. Analysis of variance indicated that isokinetic values of the control group were greater than the hallux valgus group(p<.05, p<.01).

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.187-198
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• 2003

This study was conducted to investigate the effect of design parameters of modulating valve and hydraulic clutch on the shift quality of a power shuttle transmission using a computer simulation. Computer simulation models of a hydraulic control system and a power shuttle drive train were developed and verified by an experimental power train in a laboratory. The software EASY5 was used for the modeling and simulation of the power shuttle transmission. Results of the study were summarized as follows: For a good shift quality. it is required to reduce the transient torque transmitted to the output shaft of the transmission as much as possible. This may be achieved by reducing the modulating time and clutch pressure. It was found that the design parameters most significantly affecting the modulating time and clutch pressure were the spring constant and displacement of a load piston of the modulating valve, and the spring constant and damping of the clutch piston. The modulating time decreased as the spring constant increased and increased as the displacement of the load piston decreased. The transient torque decreased as the modulating time increased. However their relationships were not always linear. As the damping decreased, both the modulating pressure and time decreased, which also resulted in a decrease in the transient torque. The spring constant of the clutch piston affected the modulating time and the peak transient torque. As the spring constant of the clutch increased, the peak transient torque decreased.