• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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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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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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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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• 제59권1호
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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.

• 한국운동역학회지
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• 제32권3호
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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.

• 산업경영시스템학회지
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• 제5권6호
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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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.

• 대한통합의학회지
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• 제6권3호
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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.

• 한국전기전자재료학회논문지
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• 제21권4호
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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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• 제24권4호
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• pp.793-802
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• 2013

현재의 스포츠영재를 선발하는 방법에는 검사 지원자의 양과 질적인 면에서 문제가 많기 때문에 선수자원의 수급이 어려운 상황이다. 전국 초등학생 5-6학년을 대상으로 시행되고 있는 국가 차원의 건강체력종합 평가시스템인 학생건강체력평가 자료는 학생들의 스포츠 잠재력을 평가할 수 있는 검사항목을 포함하고 있으므로 스포츠영재 선발하는 기초자료로 활용할 수 있다. 본 연구는 학생건강체력평가의 측정자료를 이용하여 교사가 스포츠영재 선발을 일차적으로 스크리닝하는 방법을 제안한다. 전국 모든 초등학생을 대상으로 재측정할 필요가 없으므로 시간과 비용적인 측면에서 효율적이다. 그리고 스포츠 잠재력지수를 개발하여 효율적인 스포츠영재 선발방법을 개선한다.

• Journal of Biosystems Engineering
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• 제34권5호
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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.