• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.2
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• pp.126-131
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• 2003

This study is concerned with the reduction of noise radiation by an industrial fan unit. First, spectral decomposition method is used to decompose the spectrogram obtained in experiments into source function and noise transfer function, and then major noise generation sources are investigated. Among the noise sources involved in the fan unit. this article is focused on the noise source due to vibration of panels of the unit housing. It is shown here that noise radiation associated with the panel vibration can be as significant in some frequency ranges as that associated with other noise sources such as aeroacoustic fan noise.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.192-197
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• 2001

This study is concerned with the reduction of noise radiation by an industrial fan unit. Among the noise sources involved in the fan unit, this article is focused on the noise source due to vibration of panels of the unit housing. It is shown here that noise radiation associated with the panel vibration can be as significant in some frequency ranges as that associated with other noise sources such as aeroacoustic fan noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.656-657
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• 2011

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2_spc
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• pp.327-336
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• 2020

The high-flux advanced neutron application reactor (HANARO) is a research reactor with thermal power of 30 MW applied in various research and development using neutrons generated from uranium fission chain reaction. A degasifier tank is installed in the ancillary facility of HANARO. This facility generates gas pollutants produced owing to internal environmental factors. The degasifier tank is designed to maintain the gas contaminants below acceptable levels and is monitored using an analyzer in the gas sampling panel. If condensate water is generated and flows into the analyzer of the gas sampling panel, corrosion occurs inside the analyzer's measurement chamber, which causes failure. Condensate water is generated because of the temperature difference between the degasifier tank and analyzer when the gas flows into the analyzer. A heating system is installed between the degasifier tank and gas sampling panel to suppress condensate water generation and effectively remove the condensate water inside the system. In this study, we investigated the efficiency of the heating system. In addition, the variations in the pipe temperature and the amount of average condensate water were modeled using a wall condensation model based on the changes in the fluid inlet temperature, outside air temperature, and heating cable-setting temperature.

• Journal of KSNVE
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• v.9 no.4
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• pp.785-794
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• 1999

The panel contribution analysis to reduce interior booming noise of a passenger car is carried out using both experimental method and numerical one. The accelerations of panels are measured on the outer surface of car body during operation. The acoustic characteristic of cavity is represented by two different ways. One is the acoustic transfer function obtained by experiment with reciprocal manner. The other is the boundary element model and numerical results of the model are calculated using SYSNOISE. The results from numerical method show more good agreement with measured sound pressure levels than the experimental one. Contributions of panels for interior noise are ranked and structure of the car is reinforced according to the results, which shows that the panel contribution analysis is a powerful tool to lessen structure-borne noise of passenger vehicle.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.5
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• pp.473-479
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• 2004

In this paper, power density in near field is calculated about analytic object which has comparatively large volume in considering used wavelength such as cellular base station antenna. Panel sector antenna which is used widespreadly in domestic cellular wireless communication system is modeled and electromagnetic field distribution in reactive near field region is calculated by FDTD (Finite Difference Time Domain) method. After that, antenna gain in far field region is obtain by near to far transformation. Power spectral density in radiated near field is calculated in applying to gain-based model with antenna gain in far field. Finally, compliance distance is obtained in considering the result from radiated near field calculation and basic restrictions on occupational and general public exposure limits in ICNIRP guideline. In the center of main radiating position, the result from gain-based model is -14.55 ㏈m and the result from surface scanning method is -15.75 ㏈m. When the losses from cables and connectors used in measurement are considered, the results from gain-based model and surface scanning method are nearly coincident.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.29-29
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• 2007

TFT, LCD, OLED, PDP and FED를 비롯한 많은 디스플레이 장치가 개발, 연구되고 있으며, 이러한 디스플레이 장치에 대한 수 많은 application 연구 또한 진행되고 있다. TFT-LCD는 이미 방사선 검출기로서 연구가 오랜전에 연구되어 상용화가 되었으며, LCD는 XLV로서 적용을 위한 연구가 진행되고 있으며, 그 외 수 많은 디스플레이 장치에 대한 활발한 연구가 진행되고 있는 실정이다. PDP는 대면적, 낮은 제작 비용, 높은 contrast의 이점으로 디스플레이 장치로서 활발한 연구가 진행되고 있다. 본 논문에서는 PDP를 처음으로 방사선 검출기로 적용하기 위한 연구를 수행하였다. 제작된 7 인치 AC-PDP는 다양한 가스종류 및 압력을 가진 300um의 pixel pitch룰 가진 3 전극 구조로서, coplanar readout과 대항형 readout을 통해 신호량을 분석하였다. 결과 50-100Kvp의 진단 영역의 X-ray energy에서 줄은 민감도와 훌륭한 선형성을 보였으며, 가스 종류 및 압력, 신호 검출방식에 따라 각각 다른 특성을 보였다. 이는 PDP 내 X선과의 Interaction, R/O method. Material에 강하게 의존한다.

• Journal of Biomedical Engineering Research
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• v.23 no.2
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• pp.165-170
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• 2002

The aim of this study was to analyze the effect of different sensory information on the motor function which is resulted from visual stimuli. Particularly, it was focused on the effect of complementary color stimuli on reaction time. Twenty volunteers(10 men & 10 women), between the age of 20 and 25 yearn participated in this experiment. Experiments were carried out in a light & sound-attenuated chamber, and the overall system consisted of a PC. interface card. LEDs. key board switch, and display panel. Although many measurements of sensory-motor integration has been studied the quantitative analysis of sensory-motor integration has not been developed well. Quantitative analyses were performed to investigate the effect of the different sensory information on the arm motor system in the point of view sensory-motor integration. The result showed that the reaction time for visual stimuli of complementary colors was faster than that under same color environments : and, in same color environments and the reaction speed was varied inversely with respect to the magnitude of the light wavelength.

• Journal of the Korean Institute of Gas
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• v.24 no.1
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• pp.41-48
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• 2020

This study performed a quantitative risk assessment for hydrogen-CNG complex refueling stations. Individual and societal risks were calculated by deriving accident scenarios that could occur at hydrogen and CNG refueling stations and by considering the frequency of accidents occurring for each scenario. As a result of the risk assessment, societal risk levels were within the acceptable range. However, individual risk has occurred outside the allowable range in some areas. To identify and manage risk components, high risk components were discovered through risk contribution analysis. High risks at the hydrogen-CNG complex refueling station were large leakage from CNG storage containers, compressors, and control panels. The sum of these risks contributed to approximately 88% of the overall risk of the fueling station. Therefore, periodic and intensive safety management should be performed for these high-risk elements.

• Journal of Animal Environmental Science
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• v.15 no.3
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• pp.189-198
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• 2009

This survey was conducted to investigate the situation of housing type in poultry farms in Korea. The number surveyed among the farm size over 30,000 heads was 1,965 farms. Poultry housing types of windowless, open sided, vinyl house type were 19.0, 47.7, 19.8%, respectively. Waterers of nipple, bell, and 8 feet trough used in smaller than 50,000 heads of poultry farm were 40.6, 11.3 and 42.8%, respectively. But the bigger farm in the farm size of over 100,000 heads used more nipple waterer. Feeders of disk, hopper and chain used in poultry farm were 54.5, 16.3, 15.8%, respectively. Manure collecting system of scraper and belt was 29.4, 71.5 %, respectively. Ventilation systems of natural ventilation, natural + mechanical ventilation, mechanical ventilation were 40.5, 39.8, 20.7%, respectively.