• Journal of Information Processing Systems
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• 제15권1호
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• pp.189-202
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• 2019

During thermal power coal-fired boiler operation, it is very important to detect the pulverized coal concentration in the air pipeline for the boiler combustion stability and economic security. Because the current measurement methods used by power plants are often involved with large measurement errors and unable to monitor the pulverized coal concentration in real-time, a new method is needed. In this paper, a new method based on microwave circular waveguide is presented. High Frequency Electromagnetic Simulation (HFSS) software was used to construct a simulation model for measuring pulverized coal concentration in power plant pipeline. Theoretical analysis and simulation experiments were done to find the effective microwave emission frequency, installation angle, the type of antenna probe, antenna installation distance and other important parameters. Finally, field experiment in Jilin Thermal Power Plant proved that with selected parameters, the measuring device accurately reflected the changes in the concentration of pulverized coal.

• 한국안전학회지
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• 제15권2호
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• pp.92-96
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• 2000

In this experiment, we studied about concentration characteristics of $NO_x$ and generation of ozone in the reactor of corona discharge type by using mixed gas of $NO/N_2$ and $N_2/O_2$. In the case of the initial NO concentration increased, decrease rate of NO concentration was weakened and discharge input power of minimum NO concentration became high. When NO concentration was high, NO decomposition limit was appeared. And NO reduction rate was decreased, when initial NO concentration and discharge input power increased. When discharge input power was 5W, we could know the most proper energy value for treatment of NO. When the concentration of initial NO increased, generation of ozone decreased and in the case of same concentration of NO, according to discharge input power increase, generation of ozone increased.

• 한국전기전자재료학회논문지
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• 제29권4호
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• pp.199-204
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• 2016

This paper was proposed floating island power MOSFET for lowering on state resistance and the proposed device was maintained 600 V breakdown voltage. The electrical field distribution of floating island power MOSFET was dispersed to floating island between P-base and N-drift. Therefore, we designed higher doping concentration of drift region than doping concentration of planar type power MOSFET. And so we obtain the lower on resistance than on resistance of planar type power MOSFET. We needed the higher doping concentration of floating island than doping concentration of drift region and needed width and depth of floating island for formation of floating island region. We obtained the optimal parameters. The depth of floating island was $32{\mu}m$. The doping concentration of floating island was $5{\times}1,012cm^2$. And the width of floating island was $3{\mu}m$. As a result of designing the floating island power MOSFET, we obtained 723 V breakdown voltage and $0.108{\Omega}cm^2$ on resistance. When we compared to planar power MOSFET, the on resistance was lowered 24.5% than its of planar power MOSFET. The proposed device will be used to electrical vehicle and renewable industry.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.39-40
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• 2005

Photovoltaic Power Generation system occupies an important position as an alternative energy source, converting directly sunlight into electricity,using a photovoltaic cell. The Purpose of this research is to present and confirm the effectiveness of concentration and tracking of sun in photovoltaic power generation. Comparative experiments were carried outwith two rating 75 watt solar modules in $25^{\circ}$ under condition of various times concentration, tracking and plain normal measuring generated voltages, currents and temperatures of back sheet of modules by internet monitoring system to find out which is best in economic sense. The experiments show that output power of concentration and tracking photovoltaic power generation is over 180% more then that of plain normal system.

• 대한물리치료과학회지
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• 제19권3호
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• pp.17-22
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• 2012

Background : The purpose of this study was to investigate the relationship between an agility and a concentration, an auditory reaction time and a muscle power. Methods : Twenty one healthy female college students who were 20-21 years participated in the experiment; after being introduced to the methods, they voluntarily signed a consent form. And they received several test related with this study; side step test for an agility, Harris & Harris test for a concentration, brain auditory evoked potential test for an auditory reaction time and vertical jump test for a muscle power. Result : There was no relationship between the agility and the concentration and the auditory reaction time. However, the muscle power related with the agility significantly. Conclusion : In conclusion, these findings suggest that a muscle power training is a good way to promote an agility. So, we can find out that, in an player who requires an agility, a muscle power training is the most important way for promoting an agility than a concentration training or an auditory reaction time training.

• 한국식품과학회지
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• 제35권2호
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• pp.222-228
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• 2003

팽이버섯 추출물의 수율 및 전자공여작용, 총폴리페놀함량, tyrosinase 저해작용, 갈색도, 아질산염 소거작용에 대하여 반응표면분석에 의해 추출조건을 최적화 하였다. 팽이버섯 추출물의 수율변화는 에탄올 농도에 가장 큰 영향을 받았으며, 갈변도는 microwave power 보다는 에탄올 농도에 크게 영향을 받는 것으로 나타났으며, 아질산염 소거작용의 경우 에탄올 농도가 증가할수록, microwave power가 감소할수록 증가하는 경향을 나타내었다. 전자공여작용의 경우 에탄올 농도가 증가할수록 증가폭이 컸고, microwave가 증가할수록 조금씩 증가하는 경향을 보였다. 총 폴리페놀 함량의 경우 에탄올 농도가 증가할수록, microwave power가 클수록 추출물의 생리활성이 우수한 것으로 나타나 에탄올 농도가 추출시 중요한 공정인자임을 확인 할 수 있었다. 한편, tyrosinase 저해 작용의 경우 에탄올 농도보다는 microwave power에 영향을 받았는데 power가 작을수록 그 값은 크게 측정되었다. 따라서 팽이버섯의 최적 추출조건 범위는 microwave power $47.21{\sim}76.05$ watt, ethanol 농도 $10.25{\sim}43.56%$, 추출시간 5.72분으로 예측되었다.

• 한국의류학회지
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• 제28권6호
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• pp.854-861
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• 2004

To estimate dispersion stability of particles in anionic and nonionic surfactant mixed solution, suspending power was examined as functions of duration time of suspension, ionic and nonionic surfactant mixed ratio, surfactant concentration, kinds of electrolyte, ionic strength and mole numbers of oxyethylene additions to nonionic surfactant using $\alpha$-Fe$_2$O$_3$ particle as the model of particulate soil. The suspending power of anionic and nonionic surfactant mixed solution was relatively higher than that of anionic and nonionic surfactant single solution regardless of solution concentration. The suspending power was gradually decreased with increasing duration time of suspension. In the absence of electrolyte, the effect of surfactant concentration on suspending power was small but in solution with electrolyte, suspending power was lowest at 1 ％ surfactant concentration. With 1${\times}$10$^{-3}$ ionic strength and polyanionic electrolyte in solution, the suspending power was high but effects of oxyethylene mole number to nonionic surfactant on suspending power was small. Generally the suspending power was gradually increased with decreasing the particle size. Hence the suspending power was inversely related to the particle size.

• The Journal of Korean Physical Therapy
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• 제14권2호
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• pp.172-180
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• 2002

The purpose of this paper was to make an analysis of anaerobic power in professional female basketball players using the Wingate Test Method with bicycle ergometer. Twenty-three subjects(age $21.6\pm2.8years$, body height $178.0\pm7.4cm$, body weight $70.3\pm7.4kg$) were selected from professional female basketball team whose careers were over 10years and participated in this investigation. Each subject peformed a Wingate anaerobic power test to determine total work, peak power, mean power, fatigue index and blood lactate concentration. The following were obtained from result data analysis; 1. The Total Work of athletes was a $1128.7\pm120.6watt$ 2. The Peak Power of athletes was a $449.5\pm53.1watt$ 3. The Mean Power of athletes was a $369.1\pm39.4watt$ 4. The Fatigue Index of athletes was a $33.5\pm6.9\%$ 5. The blood lactate concentration was $1.85\pm0.85mM/L$ at the normal state and $3.16\pm1.53mM/L$ at the after Wingate test. The blood lactate concentration was $6.96\pm0.81mM/L$ after 3 minute and $6.95\pm1.05mM/L$ after 5 minutes.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2003년도 춘계 학술발표회 논문집
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• pp.431-435
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• 2003

Because the Tissue Bound Tritium of food irradiates the organic tissues of a man during a longer time than the Tissue Free Water Tritium, we found the ratio of labile and bound hydrogen, which is the direct source of TBT concentration, in grain such as rice and barley. Tissue free water was extracted from rice and barley sampled, adjacent to Wolsung nuclear power plants of CANDU type, by freeze-drying. Tissue bound water was taken from some of the dried samples by high-pressure combustion. The other of the samples was washed by tritium-free water for 2-3 hours, and dried again by freeze-drying. Tissue bound water was taken again from some of the second dried samples by the combustion. The extracted tissue free and bound waters were distilled and TFWT and TBT concentrations of them were counted by a liquid scintillation counter. Through alternating washing, drying and combustion until the concentration of TBT would be constant, the tritium concentration existing as bound hydrogen was found. The ratios of labile and bound hydrogen of rice and barley were determined by TR concentration, initial TBT concentration and bound tritium concentration. The ratios of bound hydrogen of rice and barley were 0.55, 0.60 relatively.

• Corrosion Science and Technology
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• 제10권4호
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• pp.151-155
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• 2011

The iron oxide particles could be resulted from the corrosion of the circulating water system of a power plant. Because it may be one of the trouble materials which affect the power generation efficiency due to the deposition on steam generator tube and turbine blade, the continuous observation of its concentration is very important. The laser induced break-down detection (LIBD) technology was applied to monitor continuously the concentration of corrosion products with the detection limit of ppb level. The measurement system consists of a Nd:YAG pulsed laser, a polarizing beam splitter, a flow-type sample cell, an acoustic emission sensor, a high speed data acquisition board, a personal computer, etc.. The performance test results confirmed that this technology can be effective to monitor the corrosion product concentration of the circulating water system of a power plant.