• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1311-1314
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• 2005

Recently drum washing machines are required to improve not only functions, but also endurance security. The spider is one of the major parts in a drum washing machine as a power transmission device. It is needed estimating for fatigue life because it rotates at high velocity when the drum washing machine works. In this study, we tried to estimate fatigue life of the Spider with CAE and verified the accuracy by comparing the CAE results with the experimental results. The estimation method of fatigue life for the spider with CAE will be applied to raise the efficiency of time and money in the design process of a new drum washing machine.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.355-358
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• 2002

The deformation behavior of the frame for tension mask CRT is investigated by experiments and finite element method. We calculate and measure the stress-strain relation at the stress concentrations. The endurance test at 100$^{\circ}C$ was performed for checking tension decrease with time.

• Journal of Animal Science and Technology
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• v.59 no.1
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• pp.2.1-2.6
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• 2017

Background: This study aimed to analyze the on heart rate, blood lactate concentration, packed cell volume (PCV) and hemoglobin (Hb) response after conducting exercise in endurance horses. Methods: A total of 20 healthy 3-9-years-old Jeju crossbreed mares ($5.95{\pm}2.24$ year) of age and $312.65{\pm}13.59kg$ of weight) currently participating the endurance competition were used. The field tests selected for the experiment was gallop (approximately 8.3 m/s) along the selected 2.5 km course (a natural forest trail, not artificial road; a closed loop course). The horses were divided into three groups according to their age; 3-4 years of age (G1, $3.29{\pm}0.49$ year), 6-7 years of age (G2, $6.42{\pm}0.53$), and 8-9 years of age (G3, $8.50{\pm}0.55$). The measurements times for the heart rate, blood lactate concentration, PCV, and Hb analysis were conducted before exercise (T0), shortly after exercise (T1), 15 min after exercise (T2), and 30 min after exercise (T3), respectively. Data was analyzed using an analysis of covariance (ANCOVA) for repeated measures with times and groups. Results: The results of the comparison depending on the passage of rest time after exercise suggest that the heart rate and blood lactate concentration of three groups at T2 significantly decreased compared to T1 (p < 0.001). PCV of the G2 and G3 groups were significantly decreased at T2 compared to T1 (p < 0.01). Hb values at G2 (p < 0.01) and G3 (p < 0.001) groups were significantly decreased at T2 as compared to T1. However, heart rate, blood lactate concentration, PCV and Hb level at T1 showed no difference in the comparison of horses from different age groups with the exception of G3 group in terms of heart rate. Conclusion: The physiologic and hematological responses of horses during recovery time after 2,500 m exercise with gallop were no significant difference among the groups. These data are useful as a response evaluation method for training of endurance horses.

• Korean Journal of Applied Biomechanics
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• v.32 no.3
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• pp.94-102
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• 2022

Objective: The purpose of this study was to investigate the effect of acute transcranial direct current stimulation (tDCS) on the isokinetic muscular endurance of the lower extremity for young adults. Method: Thirteen young adults performed isokinetic fatigue tasks for two experimental conditions including real tDCS and sham stimulation protocols. Before and after the task, the tensiomyography was used for evaluating muscle contraction characteristics of vastus medialis and semitendinosus. Paired t-test was performed to compare the fatigue index, changes in maximum radial displacement (∆Dm), delay time (∆Tc), and velocity of contraction (∆Vc) between tDCS conditions. Results: We found no significant differences in the fatigue index between real and sham conditions. In addition, the analyses identified no significant different values of ∆Dm, ∆Tc, and ∆Vc in the vastus medialis and semitendinosus between real and sham conditions. Conclusion: These findings suggest that the tDCS protocols may have no acute effect on lower limb muscle endurance for young adults. Future studies should consider the long-term effects of repetitive tDCS sessions, various stimulation positions, exercise tasks, and participant characteristics to more clearly understand the effect of tDCS on muscle endurance of lower extremities.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.5 no.6
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• pp.41-48
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• 1982

This paper analyzed md developed flow - shop sequencing heuristic method. The essence of the heuristic approach is in the application of selective routine that reduce the size of a problem. The advantages of this approach are consistency. Speed, endurance and the ability to cope with more data and larger systems than is humanly possible, In recent years many heuristic procedures have been suggested for the flow - shop sequencing problem. Although limited comparisons of these procedures have been made, a full scale test and evaluation have not been reported previously. The maximum flow - time criterion is selected as the evaluation criterion is selected as the evaluation criterion of flow - shop's efficiency. The author evaluated these 3 heuristic method's performance. By the evaluation of the result, we can see that the modified methods produce a shorter maximum flow - time than the original methods.

• Proceedings of the KIEE Conference
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• summer
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• pp.788-790
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• 2004

This paper describes the phenomenon of the molten metal bridge theory of the arc discharge at opening contacts. And we analyze the magnetic force and drag force acting on the arc column in the DC magnetic contactor Arc cooling time by the force convection is calculated in the thermal dynamic equation using mean temperature method. Since arc gas lost conduction characteristics below a such temperature, it verify that the process of forming and extinguishing arc is able to analyze in terms of temperature characteristic by simulation and experiments of the 3 types arc extinction unit. It propose the practical simulation method to improve the electrical endurance of dc contactor.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.103-112
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• 2018

Purpose : The purpose of this study was to determined the effects of resistance and aerobic exercise on gait ability, physical fitness and body compositions in older women. Method : The subjects were 24 older women who were randomly divided into two groups (resistance exercise, n=12, and aerobic exercise, n=12). They 65~80 years old. The subjects done the Gym-ball, Togu, and senior dance exercise three times per week-for 70 minutes each time for 16 weeks. Body compositions, physical fitness, and gait ability were measured in this study. Result : There were significantly improved the walk performance after exercise training for 16 weeks. In particular, it was more effective on resistance exercise training in older women. There were significant differences in muscle endurance, flexibility, balance, body weight, percent of body fat, and body mass index (BMI) after the exercise program. Conclusion : It was more effective improved on muscle endurance, flexibility, and balance performance after resistance exercise program than an aerobic exercise program in older women.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.4
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• pp.300-304
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• 2008

A novel characterization method was investigated to estimate the trap generation during the program /erase cycles in nand flash memory cell. Utilizing Fowler-Nordheim tunneling current, floating gate potential and oxide electric field, we established a quantitative model which allows the knowledge of threshold voltage (Vth) as a function of either program or erase operation time. Based on our model, the derived results proved that interface trap density (Nit) term is only included in the program operation equation, while both Nit and oxide trap density (Not) term are included in the erase operation equation. The effectiveness of our model was tested using 50 nm nand flash memory cell with floating gate type. Nit and Not were extracted through the analysis of Program/Erase speed with respect to the endurance cycle. Trap generation and cycle numbers showed the power dependency. Finally, with the measurement of the experiment concerning the variation of cell Vth with respect to program/erase cycles, we obtained the novel quantitative model which shows similar results of relationship between experimental values and extracted ones.

• Journal of the Korean Data and Information Science Society
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• v.24 no.4
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• pp.793-802
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• 2013

There are many problems to single sports talents out of test applicants. The physical activity promotion system has been performed to all elements school students of both 5 and 6 grades in order to evaluate overall health and physical activities since 2009. This system includes some variables which could measure the students' sports latent power, so that the system could be used to single out sports talents. In this work, we propose a primary screening method that element school teachers might evaluate sports talents based on the data of the physical activity promotion system. Two more sports talent indices which are sports flexibility index and sports endurance index are defined. The selection method of sports talents is developed by using sports latent indices including sports power and cardiorespiratory indices. This method is efficient from the view of time and cost aspects, since we do not need to remeasure all elements school students again.

• Journal of Biosystems Engineering
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• v.34 no.5
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• pp.325-330
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• 2009

This study was performed to develop accelerated life test methods for agricultural tractor transmission receiving variable load. To acquire parameters for calculation of accelerated life test, endurance tests were performed under different torque conditions. Test results showed that the shape factor of Weibull distribution was 1.5 and fatigue damage exponent was 5.4. The calculated test time was 5,877 hours under the conditions of average life (MTBF) 3,000 hours and 90% reliability for one test sample. According to the linear cumulative damage rule, test time could be reduced using increased test load. Test time could be reduced by 252 hours when 1.2 times of the rated load compared with 0.67 times of the rated equivalent load calculated by load spectrum of the agricultural tractor. Calculated acceleration coefficient was 23.3.