• 한국기후변화학회지
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• 제7권4호
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• pp.433-442
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• 2016

In this study, we examine future changes in surface radiation associated with cloud amount and aerosol emission over East Asia. Data in this study is HadGEM2-CC (Hadley Centre Global Environmental Model version 2, Carbon Cycle) simulations of the Representative Concentration Pathways (RCPs) 2.6/4.5/8.5. Results show that temperature and precipitation increase with rising of the atmosphere $CO_2$. At the end of $21^{st}$ century (2070~2099) relative to the end of $20^{st}$ century (1981~2005), changes in temperature and precipitation rate are expected to increase by $+1.85^{\circ}C/+6.6%$ for RCP2.6, $+3.09^{\circ}C/+8.5%$ for RCP4.5, $+5.49^{\circ}C/10%$ for RCP8.5. The warming results from increasing Net Down Surface Long Wave Radiation Flux (LW) and Net Down Surface Short Wave Radiation Flux (SW) as well. SW change increases mainly from reduced total Aerosol Optical Depth (AOD) and low-level cloud amount. LW change is associated with increasing of atmospheric $CO_2$ and total cloud amount, since increasing cloud amounts are related to absorb LW radiation and remit the energy toward the surface. The enhancement of precipitation is attributed by increasing of high-level cloud amount. Such climate conditions are favorable for vegetation growth and extension. Expansion of C3 grass and shrub is distinct over East Asia, inducing large latent heat flux increment.

• Journal of Astronomy and Space Sciences
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• 제11권1호
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• pp.131-145
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• 1994

Cosmic Ray Experiment (CRE)는 KITSAT-1 의 여 러 module 중 하나로 Total D Dose Experiment (TDE) 와 Cosmic Particle Experiment (CPE) 두개의 sub-system 으로 구성되어 있다. CRE 의 목적은 KITSAT-1 궤도에서의 우주 환경을 조사하는 것이다. KITSAT-1 의 궤도는 inner Van Allen belt에 위치하며, 이 지역 에셔는 고에너지 proton들이 많이 분포하고 있어 위성체에 단기적인 또는 장기적인 radiation 효과를 미치고 있다. 1년여의 설험 결과로부터 Van Allen belt가 무척 안정되어 있고 태양의 활동이 CPE,TDE 및 SEU (Single Event Upset) rate 에 영향을 줌을 알 수 있었다. 또한 CREME code 에 의해 예상됐던 것보다 많은 고에너지 입자 flux가 관찰되었다.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.517-523
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• 2003

방사선장 하에서의 탈기막 재질의 물성에 미치는 방사선의 영향에 관한 연구를 수행하였다. PP에 미치는 방사선속을 계산하기 위해 MCNP4A Code를 이용하였으며 MCNP4A Code를 이용한 광자선속을 계산하기 위하여 탈기장치와 PP 막을 봉 구조로 규격화하였다. 양단차폐 계통에 사용되는 탈기막 재질인 PP의 변형은 계통수의 방사능이 매우 낮기 때문에 거의 없을 것으로 평가되었으며 작업자의 피폭도 무시할 정도인 것으로 판단되었다. 검토결과, 원자력발전소의 원자로 계통수 처리를 위해 방사선장하에서 노출되는 폴리프로필렌 탈기막의 재질은 건전성이 그대로 유지될 수 있음을 평가하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.422-426
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• 2005

This experimental study represents the results of an analysis on the characteristics of flux density distribution in the focal region of solar concentrator. The characteristics of flux density distributions are investigated to optimally design and position a cavity receiver. This was deemed very useful to find and correct various errors associated with a dish concentrator. We estimated the flux density distribution on the target placed along with focal lengths from the dish vertex to experimentally determine the focal length. It is observed that the actual focal point exists when the focal length is 2.17m. The total integrated power and percent power was 2467W and $85.8\%$, respectively, in the case of small dish, and also 2095W and $79\%$, respectively, in the case of KIERDISH II. As a result of the percent power within radius, approximately $90\%$ of the incident radiation is intercepted by about 0.06 m radius. The minimum radius of receiver in KIERDISH II is found to be 0.15m and approximately $90\%$ of the incident radiation is intercepted by receiver aperture.

• 한국환경과학회지
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• 제15권7호
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• pp.653-657
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• 2006

Based on the monthly weather report of Korea Meteorological Administration (KMA) and daily sea surface temperature (SST) data from National Fisheries Research and Development Institute (NFRDI) (1995-2004), mean heat fluxes were estimated at the port of Yeosu. Net heat flux was transported from the air to the sea surface during February to September, and it amounts to $205 Wm^{-2}$ in daily average value in May. During October to January, the transfer of net heat flux was conversed from the sea surface to the air with $-70 Wm^{-2}$ in minimum of daily average value in December. Short wave radiation was ranged from $167 Wm^{-2}$ in December to $300 Wm^{-2}$ in April. Long wave radiation (Sensible heat) was ranged from $27 (-14) Wm^{-2}$ in July to $90 (79) Wm^{-2}$ in December. Latent heat showed $42 Wm^{-2}$ with its minimum in July and $104 Wm^{-2}$ with its maximum in October in daily average value.

• 한국환경과학회지
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• 제5권5호
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• pp.657-662
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• 1996

여름과 겨울철에 준건조 유역들 (Lucky Hills and Kendall)로부터 측정되어진 기상학적 그리고 flux data를 이용하여 증발산 산정을 위한 변수들의 민감도를 연구하였다. 상대적 민감도 분석을 이용하여 Pen농an의 잠재증발산 산정에 필요한 네 가지 기상학적 그리고 flux변수(순방사, 풍속, 공기온도 그리고 상대습도)들의 중요도가 검증되어졌다. 두 다른 유역으로부터의 연구 결과에 의하면, 여름철에 Pen-mim의 잠재증발산략의 변화는 공기 온도와 순방사에 의해서 지배되어지고, 겨울철에는 상대습도와 공기온도에 의해서 지배되어지는 것으로 나타났다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.68-71
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• 2008

Our goal is to obtain a better scientific understanding how to define the nature and role of remotely sensed land surface parameters and energy fluxes in the heat island phenomena, and local and regional weather and climate. By using the MODIS visible and thermal imagery data and analyzing the surface energy flux images associated with the change of the landcover and landuse in study area, we will estimate and present how significant is the magnitude of the heat island heat effect and its relation with the surface parameters and the energy fluxes in Taiwan. To achieve our objective, we used the energy budget components such as net radiation, soil heat flux, sensible heat flux, and latent heat flux in the study area of interest derived form remotely sensed data to understand the island heat effect. The result shows that the water is the most important component to decrease the temperature, and the more the consumed net radiation to latent heat, the lower urban surface temperature.

• 한국화재소방학회논문지
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• 제21권3호
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• pp.78-83
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• 2007

석유류 중에서도 차량, 선박, 보일러 등에 많이 사용되고 있는 디젤유는 휘발유나 등유보다도 연소시에 발열량이 높기 때문에, 화재 발생시에 큰 피해를 초래한다. 따라서 본 연구는 시중에 판매중인 디젤유을 이용하여 액면화재 실험을 하였으며, 연소시에 화염의 내부온도와 화염으로부터 발생되는 복사열에 대해서 측정하였다. 디젤유의 순간 최대화염온도는 $900^{\circ}C$ 이상되는 것으로 나타났으며, 평균 최대화염온도는 $800^{\circ}C$ 이상으로 나타났다. 또한 최대화염온도는 가연성 액체의 표면으로부터 5 H/D에서 나타났으며, 이 거리 보다 멀어질 수로 화염의 온도는 낮아졌다. 복사열의 경우 저장용기의 크기와 시료의 량에 따라서 크게 달라지는 것을 알 수 있었으며, 실험 용기의 크기가 0.5 m이고, 시료량이 13 mm와 20 mm에서는 각각 92.29 kW와 117.43 kW로 나타났으며, 크기가 1.0 m의 용기에서는 각각 364.35 kW와 405.88 kW로 나타났다.

• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1324-1329
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• 2018

This study presents a practical application of complementary safety indicators, which can be applied in a safety assessment of a radioactive waste repository by excluding a biosphere simulation and comparing the artificial radiation originating from the repository with the background natural radiation. Complementary safety indicators (radiotoxicity flux from geosphere and radiotoxicity concentration in seawater) were applied in the safety assessment of a rock-cavern type low and intermediate level radioactive waste (LILW) repository in the Republic of Korea. The natural radionuclide ($^{40}K$, $^{226,228}Ra$, $^{232}Th$, and $^{234,235,238}U$) concentrations in the groundwater and seawater at the Gyeongju LILW repository site were measured. Based on the analyzed concentrations of natural radionuclides, the levels of natural radiation were determined to be $8.6{\times}10^{-5}$ - $8.0{\times}10^{-4}Sv/m^2/yr$ and $6.95{\times}10^{-5}Sv/m^3$ for radiotoxicity flux from the geosphere and radiotoxicity concentration in seawater, respectively. From simulation results obtained using a Goldsim-based safety assessment model, it was determined that the radiotoxicity of radionuclides released from the repository is lower than that of the natural radionuclides inherently present in the natural waters. The applicability of the complementary safety indicators to the safety case was discussed with regard to reduction of the uncertainty associated with biosphere simulations, and communication with the public.

• 한국태양에너지학회 논문집
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• 제35권3호
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• pp.65-71
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• 2015

A solar thermal simulator is suitable for indoor experiments of solar receivers and reactors when solar insolation and weather conditions are not favorable. Moreover, due to the easy control of electric power input, the solar thermal simulator allows the adjustment of power input incident on solar receivers and reactors and thus the implementation of accurate experiments. We manufactured a solar simulator, which is comprised of three sets of a xenon lamp and an elliptical reflector. In order to serve as a test facility, optical characterization of the solar simulator via radiation heat flux measurement is a critical prerequisite. We applied the flux mapping method to measuring the heat flux distribution of the three lamps. We presented the measurement results in terms of the heat flux distribution, the peak heat flux, the power distribution, the maximum power, and the efficiency for electric power conversion into radiation power. Characterization results show that our solar simulator provides the peak heat flux of $3,019kW/m^2$, the maximum power of 16.9 kW, and the conversion efficiency of 45%, additionally with a 10% operation margin for output increase.