• 대한의용생체공학회:의공학회지
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• 제28권2호
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• pp.229-234
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• 2007

Diffuse optical tomography (DOT) is a relatively new medical imaging modality which uses near infrared light to image large-sized tissues noninvasively. We constructed a frequency-domain DOT system to measure the optical properties of optical phantoms and human tissues. The FD-DOT uses the intensity-modulated infrared light source that illuminates the biological tissues. The phase shift and modulation changes at each detector site are separately processed to measure the optical properties. The absorption and scattering coefficients are separately estimated using inverse algorithms.

• 한국의류학회지
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• 제26권10호
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• pp.1436-1442
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• 2002

In this paper, the effect of the loess and mud of an inorganic substance dyed on cotton knitting fabrics have been studied The structure and chemical composition of loess and mud was analyzed. And the Far-Infrared emissivity and emission power, colorfastness, anti-bacterial properties cotton knitting fabrics dyed with loess and mud were also evaluated. The structure and chemical composion of loess and mud was almost identical structure and to be alike main components were SiO$_2$, Al$_2$0$_3$ and Fe$_2$O$_3$. The cotton hitting fabrics dyed with loess and mud have good colorfastness and anti-bacterial properties. when the dyed fabrics was after-treated with diphenyl ether, the anti-bacterial property were improved. Far-Infrared emissivity and emission power cotton knitting fabrics dyed with loess and mud have very good.

• 대한의용생체공학회:의공학회지
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• 제29권2호
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• pp.89-98
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• 2008

NIRS (Near-infrared Spectroscopy) and DOI (Diffuse Optical Imaging) are relatively new, non-invasive, and non-ionizing methods that measure or image optical properties (Scattering and Absorption Coefficient) and physiological properties (Water Fraction, concentration of Oxy-, Deoxy-Hemoglobin, Cytochrome Oxidase, etc) of biological tissues. In this paper, three different types of NIRS systems, mathematical modeling, and reconstruction algorithms are described. Also, recent applications such as functional brain imaging, optical mammography, NIRS based BMI (Brain-Machine Interface), and small animal study are reviewed.

• 천문학회보
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• 제41권2호
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• pp.62.1-62.1
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• 2016

We study the near-infrared photometric properties of red-supergiant stars (RSGs) in three nearby galaxies located within 15 Mpc: NGC 4214, NGC 4736 and NGC 5194 / NGC 5195. The near-infrared (JHK) imaging data were obtained using the WFCAM detector mounted on UKIRT telescope in Hawaii. We used the DAOPHOT/ALLSTAR pacakge to carry out the photometry. We applied MARCS synthetic fluxes to estimate the effective temperatures and luminosities of the RSGs in all the three galaxies. The results were plotted in the Hertzsprung-Russell(H-R) diagram along with the theoretical evolutionary tracks with different masses. We explore the spatial correlation between the RSGs and H II regions by examing the H-R diagram of the RSGs in the dominant H II regions for each of these three galaxies.

• Journal of Astronomy and Space Sciences
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• 제9권2호
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• pp.183-192
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• 1992

We have investigated the properties of dust grains in the envelopes of infrared carbon stars by testing various radiative transfer model spectra with different stellar and enveloped parameters. We have deduced a new opacity pattern for the dust grains reflecting both the experimental data and the model fitting with recent infrared observations. The best pattern we find is very similar to amorphous carbon with a slight modification that could be attributed to some unknown dust grain materials. Unlike oxygen-rich dust grains, the optical properties of carbon grains do not show any reasonable tendency of temperature dependence. We find that the Planck mean values of radiation pressure efficiency factors for the modified amorphous carbon are much larger than those for graphite.

• 천문학회지
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• 제43권6호
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• pp.213-223
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• 2010

Young Stellar Objects (YSOs) in the early evolutionary stages are very embedded, and thus they emit most of their energy at long wavelengths such as far-infrared (FIR) and submillimeter (Submm). Therefore, the FIR observational data are very important to classify the accurate evolutionary stages of these embedded YSOs, and to better constrain their physical parameters in the dust continuum modeling. We selected 28 YSOs, which were detected in the AKARI Far-Infrared Surveyor (FIS), from the Spitzer c2d legacy YSO catalogs to test the effect of FIR fluxes on the classification of their evolutionary stages and on the constraining of envelope properties, internal luminosity, and UV strength of the Interstellar Radiation Field (ISRF). According to our test, one can mis-classify the evolutionary stages of YSOs, especially the very embedded ones if the FIR fluxes are not included. In addition, the total amount of heating of YSOs can be underestimated without the FIR observational data.

• 한국가정과학회지
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• 제5권2호
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• pp.93-99
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• 2002

In this paper, the effect of the mud of an inorganic substance dyed on cotton knitted fabrics have been studied. The structure and chemical composition of mud was analyzed. And the far-infrared emissivity and emission power, colorfastness, anti-bacterial properties cotton knitted fabrics dyed with mud were also evaluated. The structure and chemical composition of mud was almost identical structure and to be alike main components were SiO2, A1203 and Fe203. The cotton knitted fabrics dyed with mud have good components and anti-bacterial properties. when the dyed fabrics was after-treated with diphenyl ether, the anti-bacterial property were improved. Far-infrared emissivity and emission fewer cotton knitted fabrics dyed with mud have very good.

• 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.

• 천문학논총
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• 제32권1호
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• pp.179-183
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• 2017

AKARI and the subsequent Herschel Space Observatory have yielded tremendous advancement in our knowledge of the infrared-submillimeter properties of active galaxies and active galactic nuclei, AGN. This short review describes some highlights. Active galaxies are found to do what they are supposed to do: build up their stellar bodies while building up their central black holes.

• 한국표면공학회지
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• 제35권3호
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• pp.149-157
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• 2002

Spectral emissivity depends on the surface conditions of the materials. The mechanisms that affect the spectral emissivity in anodic oxide films on aluminum were investigated. The aluminum specimens were anodized in a sulfuric acid solution and the thickness of the resulting oxide film formed changed with the anodizing time. FT-IR spectrum analysis identified the anodic oxide film as boehmite ($Al_2$$O_3$.$H_2$O). Both the infrared emisivity and reflectivity of the anodized aluminum were affected by the structure of the anodic oxide film because Al-OH and Al-O-Al have a pronounced absorption band in the infrared region of the spectrum. The presence of an anodic oxide film on aluminum caused a rapid drop in the infrared reflectivity. An aluminum surface in the clean state had an emissivity of approximately 0.2. However, the infrared emissivity rapidly increased to 0.91 as the thickness of the anodic oxide film increased.