• 한국재료학회지
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• 제9권12호
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• pp.1205-1210
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• 1999

분무건조법으로 용사용 원적외선 세라믹/알루미늄 복합분말을 제조하여 플라즈마 용사법으로 알루미늄 모재에 용사한 후, 미세구조, 결정상, 열충격저항성 그리고 분광복사율을 조사하였다. 분무건조된 복합분말의 입형은 구형으로 34~105${\mu}m $. 영역에서 높은 복사율을 보였다. 그러나 알루미늄 첨가량이 증가할수록 원적외선 방사특성은 감소하였다. 결과적으로 용사법으로 원적외선 방사특성의 큰 손실 없이 방사체를 제조하기 위해서는 20~30%wt%Al를 첨가하여 복합분말을 제조하는 것이 가장 효율적이라고 판단된다.

• 한국지구과학회지
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• 제38권4호
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• pp.269-282
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• 2017

이 연구에서는 Earth Observing System Terra 위성에 탑재된 Moderate Resolution Imaging Spectroradiometer (MODIS) 협대역 방출율(채널 29, 30, 31) 자료와 다중선형회귀모형을 이용하여 지표면 광대역 방출율을 추정하였다. 다중선형회귀모형 도출 및 검증을 위한 분광 방출율 자료는 MODIS University of California, Santa Barbara와 Advanced Spaceborne Thermal Emission and Reflection Radiometer spectral library의 307종(토양 123종, 식생 32종, 물 19종, 인위적 재료 43종, 바위 90종)을 사용하였다. 도출된 다중선형회귀모형의 결정계수($R^2$)는 0.95 (p<.001)로 높게 나타났고 또한 이 모형 결과와 이론적 광대역 방출율 값의 평균제곱근오차(Root Mean Square Error)는 0.0070이었다. 그리고 이 연구 결과에 따라 계산된 지표면 광대역 방출율을 선행 연구 Wang et al. (2005)의 결과와 비교하였다. 그 결과 아시아, 아프리카, 오세아니아 지역에서 이 연구와 Wang et al. (2005)의 결과에 대한 1월 평균 지표면 광대역방출율의 평균제곱근오차는 0.0054이었고 최소와 최대 편차는 각각 0.0027과 0.0067이었으며 이러한 통계 값은 8월에도 유사하였다. 이 연구에서 다중선형회귀모형에 의하여 계산한 지표면 광대역 방출율은 Wang et al. (2005)의 값과 큰 차이가 없이 비교적 정확하게 산출되었으나 산출 정확성 향상을 위해서는 토지피복특성에 따른 차별화된 회귀모형 적용 필요성이 제기된다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2044-2049
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• 2007

In order to predict the thermal radiation induced from alumina particle cloud in the plume of solid propellant motor, view factor method is applied to space shuttle SRB and the result is compared with that of monte carlo method. For this purpose, radiative characteristics, such as particle cloud temperature distribution, effective emissivity or emissive power of particle cloud are studied. In the case of effective emissivity, inverse wavelength method is applied and plume reduction characteristic length is used for emissive power distribution. As a result, thermal radiation using view factor method gives more conservative results than that using monte carlo method. So it can be used for preliminary design of thermal protection system.

• 환경영향평가
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• 제18권4호
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• pp.219-227
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• 2009

Because of urban development and changed land cover types, It is very important to acquire pixel unit of land surface temperature(LST) information when the heat island effect(HIE) of regional area are investigated. The brightness temperature observed by satellite is very useful for assessing the pixel unit of LST distributions for the analysis of thermal environment problems of urban areas. Also, satellite land cover data are very useful to our understanding of surface conditions of study areas. In this study, brightness temperature information of Landsat TM thermal channel was analyzed and compared with land cover information of Jeon-ju city. The atmospheric correction of TM thermal channel carried out to explain for compared LST long term monitoring errors. However, simple estimation and evaluation methods to find a physical relationship between LST from satellite images and in-situ data are compared with reference channel emissivity.

• 한국세라믹학회지
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• 제31권9호
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• pp.975-980
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• 1994

The thermal properties of cordierite (2MgO.2Al2O3.5SiO2)+30 wt% clay+ Xwt% MnO2 of infrared radiator have been investigated as a function of MnO2 additives (X=0,0.1,0.25,0.5,1.0,1.5,2.0,2.5). The thermal expansion coefficient was decreased with increasing amounts of MnO2 additives. Otherwise, the spectral emissivity was increased in the below 4.5 ${\mu}{\textrm}{m}$ wavelength. Also, the infrared radiator of cordierite system which spectral emissivity was approximately 1.0 can be attainable at from 4.5 ${\mu}{\textrm}{m}$ to 8 ${\mu}{\textrm}{m}$ wavelength. The spectral emissivity was decreased from 8 ${\mu}{\textrm}{m}$ to 14 ${\mu}{\textrm}{m}$ above X=2.5.

• 한국염색가공학회지
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• 제31권4호
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• pp.268-275
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• 2019

In this study, silk fabrics was dyed with sappan wood extracts fermented for 5 and 15 days, respectively, and then the dyeability, durability and the functionality of the dyed silk were investigated. Before dyeing, the silk was pretreated with chitosan-acetic acid solution or chitosan acetic acid and illite blend solution. Thereafter, UV-Visible transmittance, color, fastness, antimicrobial activity, and the FIR emissivity were analyzed. As a result, the K/S value was higher in the samples that were not pre-treated or fermented. Regardless of fermentation, the lightfastness was not significantly different. The color fastness to washing was slightly better when the samples were pretreated with chitosan-acetic acid and illite, and then dyed with extracts fermented 5 days. In addition, all samples showed high antimicrobial activity of 99.9%, regardless of the fermentation. Far-infrared emissivity was confirmed to be slightly increased by the illite and chitosan-acetic acid solution treatment compared to the untreated sample.

• Transactions on Electrical and Electronic Materials
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• 제18권1호
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• pp.13-15
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• 2017

Low emissivity glass for high transparency in the visible range and low emissivity in the IR (infrared) range was fabricated and investigated. The multilayers were have been fabricated, and consisted of two outer oxide layers and a middle layer of Ag as a metal layer. Oxide layers were formed by rf sputtering and metal layers were formed using by an evaporator at room temperature. SiInZnO (SIZO) film was used as an oxide layer. The OMO (oxide-metaloxide) structures of SIZO/Ag/SIZO were analyzed by using transmittance, AFM (atomic force microscopye), and XRD (X-ray diffraction). The OMO multilayer structure was designed to investigate the effect of Ag layer thickness on the optical property of the OMO structure.

• 항공우주기술
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• 제10권1호
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• pp.156-166
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• 2011

천리안위성은 대한민국 최초의 정지궤도 지구관측위성으로써 기상탑재체와 해양탑재체를 이용하여 24시간 지구관측 임무를 수행한다. 위성은 궤도상 시험을 성공적으로 완료하고 2011년 4월부터 정상운영 중이다. 본 논문에서는 천리안위성 기상탑재체의 스캔미러 방사율 보정 알고리즘 및 이의 소프트웨어 구현에 대해서 설명한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1317-1319
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• 1994

The thermal properties of Cordierite$(2MgO.2Al_2O_3.5SiO_2)$ + 30 [wt%]clay + X[wt%]MnO_2$ of infrared radiator have been investigated as a function of $MnO_2$ additives (X=0, 0.1, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5). The thermal expansion coefficient was decreased and the spectral emissivity was increased only in the below $4.5{\mu}m$ wavelength with increasing amaunts(wt%) of $MnO_2$ additives. Also, the infrared radiator of Cordierite system which spectral emissivity was approximately 1.0 can be attainable at from $4.5{\mu}m$ to $8{\mu}m$ wavelength. The spectral emissivity was decreased from $8{\mu}m$ to $14{\mu}m$ at X=2.5.

• Journal of applied mathematics & informatics
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• 제29권5_6호
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• pp.1257-1268
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• 2011

The thermal behavior of wood exposed to the outdoors is influenced by solar absorptivity and longwave emissivity. However, it is difficult to measure that properties directly. Hence we estimate the values of the parameter by using the least-square optimization technique. Finally we report the results for the computation of the values of the parameters.