• Title/Summary/Keyword: Infrared(IR)

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RETRIEVAL OF LOCAL INTERPLANETARY DUST EMISSIVITY BY ASTRO-F

  • HONG S. S.;KWON S. M.;PYO J.;UENO M.;ISHIGURO M.;USUI F.;WEINBERG J. L.
    • Journal of The Korean Astronomical Society
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    • v.37 no.4
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    • pp.159-169
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    • 2004
  • This is a proposal to probe local part of the interplanetary dust (IPD) cloud complex and retrieve mean volume emissivity of the local IPDs at mid-infrared wavelengths. This will be done by monitoring, with Infrared Camera (IRC) aboard the ASTRO-F, the annual modulation of the zodiacal emission. In pointing mode of the ASTRO-F mission the spacecraft can make attitude maneuvering over approximately ${\pm}1^{\circ}$ range centered at solar elongation $90^{\circ}$ in the ecliptic plane. The attitude maneuvering combined with high sensitivity of the IRC will provide us with a unique opportunity observationally to take derivatives of the zodiacal emission brightness with respect to the solar elongation. From the resulting differential of the brightness over the ${\pm}1^{\circ}$ range, one can directly determine the mean volume emissivity of the local IPDs with a sufficient accuracy to de-modulate the annual emissivity variations due to the Earth's elliptical motion and the dis-alignment of the maximum IPD density plane with respect to the ecliptic. The non-zero eccentricity ($e_{\oplus}$= 0.0167) of the Earth's orbit combined with the sensitive temperature dependence of the Planck function would bring modulations of amplitude at least $3.34\%$ to the zodiacal emission brightness at mid-infrared wavelengths, with which one may determine the IPD temperature T(r) and mean number density n(r) as functions of heliocentric distance r. This will in turn fix the power-law exponent $\delta$ in the relation $T(r) = T_o(r/r_o)^{-\delta}$ for the dust temperature and v in $n(r) = n_o(r/r_o)^-v$ for the density. We discuss how one may de-couple the notorious degeneracy of cross-section, density, reference temperature $T_o$ and exponent $\delta$.

Large scale interactive display system for touch interaction in stereopsis (입체 영상에서 터치 인터랙션을 위한 대규모 인터랙티브 디스플레이 시스템)

  • Kang, Maeng-Kwan;Kim, Jung-Hoon;Jo, Sung-Hyun;Joo, Woo-Suck;Yoon, Tae-Soo;Lee, Dong-Hoon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2010.10a
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    • pp.252-255
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    • 2010
  • In this thesis, it suggests large scale interactive display system which is able to various touch interaction and bases on infrared LED BAR and using 3D. Interaction layer formed on space from screen which is able to feel 3D using suggested IR LED BAR. It gets the image in real time what is composed in interaction section using infrared camera with band pass filter. The image finds touch interaction coordinate through image processing module and saves as packet. It send packet to server through network data communication. It analyze packet by metaphor analysis module and save as metaphor event and send it to contents. On contents, it practices to metaphor event result in real time so it makes use touch interaction in stereopsis. According to this process, it does not need touch the screen at firsthand but it is possible system and touch interaction so touch interaction is possible while use 3D.

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Development of IR Thermal Camera Detector based on Smartphone Interlocking for Hidden Camera Crime Prevention (몰래카메라 범죄방지를 위한 스마트폰 연동 기반의 IR 열카메라 탐지기 개발)

  • Kang, Young-Gil;Cho, Pil-Gu;Kim, Young-Gon
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.6
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    • pp.1-8
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    • 2021
  • The performance of hidden camera cameras is improving day by day due to miniaturization and advanced technology integration according to the speed of technological development of smartphones. As this external networking computing environment is advanced and diversified, exposure to hidden cameras in addition to general safety cameras is also increasing. On the other hand, the technology for detecting and preventing hidden cameras is not keeping up with the development and speed of these hidden cameras. Therefore, in this study, the heat of the hidden camera was detected using infrared thermal detection technology based on general image and thermal image synthesis technology, and the reflectance of each wavelength according to the difference in ambient temperature was analyzed to reduce the false positive rate.

Discrimination of Cultivars and Cultivation Origins from the Sepals of Dry Persimmon Using FT-IR Spectroscopy Combined with Multivariate Analysis (FT-IR 스펙트럼 데이터의 다변량 통계분석을 이용한 곶감의 원산지 및 품종 식별)

  • Hur, Suel Hye;Kim, Suk Weon;Min, Byung Whan
    • Korean Journal of Food Science and Technology
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    • v.47 no.1
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    • pp.20-26
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    • 2015
  • This study aimed to establish a rapid system for discriminating the cultivation origins and cultivars of dry persimmons, using metabolite fingerprinting by Fourier transform infrared (FT-IR) spectroscopy combined with multivariate analysis. Whole-cell extracts from the sepals of four Korean cultivars and two different Chinese dry persimmons were subjected to FT-IR spectroscopy. Principle component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) of the FT-IR spectral data successfully discriminated six dry persimmons into two groups depending on their cultivation origins. Principal component loading values showed that the 1750-1420 and $1190-950cm^{-1}$ regions of the FT-IR spectra were significantly important for the discrimination of cultivation origins. The accuracy of prediction of the cultivation origins and cultivars by PLS regression was 100% (p<0.01) and 85.9% (p<0.05), respectively. These results clearly show that metabolic fingerprinting of FT-IR spectra can be applied for rapid discrimination of the cultivation origins and cultivars of commercial dry persimmons.

Analysis of ambers with different origin by IR and py/GC/MS (산지별 호박(amber)의 IR 및 py/GC/MS 특성 분석)

  • Park, Jong-Seo;Lim, Yu-Jin
    • Analytical Science and Technology
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    • v.24 no.4
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    • pp.256-265
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    • 2011
  • Ambers have been used as a gemstone and a religious object since the ancient times and found in several archaeological sites in Korea. To prepare an enhanced conservation measures, we surveyed the chemical and spectroscopic properties of the ambers according to the provenance. Total 14 amber samples were collected from 6 different provenances including Baltic, Chiapas, Colombian, Dominican, Fushun and Madagascar amber. Infrared (IR) spectroscopic analysis was conducted for the non-destructive examination of the amber samples. They were also analyzed with pyrolysis/GC/MS (py/GC/MS) at the pyrolysis temperature of $300^{\circ}C$ with the on-line derivatization to trimethylsilyl ester. Baltic shoulder corresponding to the absorption at $1250cm^{-1}{\sim}1150cm^{-1}$ appeared in the IR spectrum of Baltic amber. IR spectra of the other ambers also showed somewhat distinctive characteristic peaks. In py/GC/MS analysis peaks assignable to succinic acid, dehydroabietic acid and pimaric acid were detected, which are known to be the components of the amber. In the meanwhile, the presence of compounds appearing in certain amber will be applied to differentiate the provenances of amber relics if their fragments are available for the analysis. These results are expected to help the confirmation of archaeological amber relics and archaeometric interpretation of provenances and manufacturing techniques.

Starburst and AGN activity in local infrared luminous galaxies

  • Lee, Jong-Chul
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.55.1-55.1
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    • 2011
  • Luminous infrared galaxies (LIRGs; $L_{IR}$ > ${10^{11}}_{Lsun}$) are the most powerful objects in the local Universe. Previous work suggested that dust re-processing of starburst and/or active galactic nuclei (AGN) activity, triggered by galaxy interactions, is responsible for their enormous infrared emission. To understand the nature of LIRGs, it is essential to determine their spectral types. Optical spectral types of 115 ultraluminous infrared galaxies in the southern sky are presented using CTIO observations. The AGN fraction is on average 50% and increases with infrared luminosity. Near-infrared spectral types of 36 LIRGs are also presented based on AKARI observations. In the sample, 12 optically elusive buried AGNs are found. To investigate the evolutionary sequence of LIRGs, star formation histories of ~6000 LIRGs in the SDSS and IRAS/AKARI matched sample are derived by comparing observed optical spectra and stellar population models. AGN-dominated LIRGs are currently massive relative to starburst-dominated LIRGs, which originates from an enhancement of star formation at intermediate-ages. For ~1100 early-type LIRGs, optical and NIR fundamental planes (FPs) are constructed. The FP of LIRGs is significantly different from that of normal early-type galaxies, but the difference is minimized in low luminous and AGN-like LIRGs. These findings support that the importance of AGN is growing as infrared luminosity increases and that LIRGs follow at least in the high mass regime the standard evolutionary scenario: starburst LIRGs evolve into AGN LIRGs and finally into normal early-type galaxies.

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The effect of Infrared and ultrasound for the formation of collagen fiber in scar tissue of rats (적외선과 초음파의 적용이 흰쥐 반흔 조직 콜라겐 침착에 미치는 영향)

  • Jun Kyoung-hee;Park Rae Joon
    • The Journal of Korean Physical Therapy
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    • v.14 no.2
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    • pp.190-198
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    • 2002
  • This study was investigated the effects of near Infrared St ultrasound for collagen fiber in open wounded of rats skin. Each group was treated under the following conditions; group I was applied near IR , group II was applied 0.5 MHz continue wave US and group III was control group. The results were prominent in observation of scar tissue and of fibroblast infiltration of group I & II.

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Photometry of the long-period eclipsing polar V1309 Ori

  • Kim, Y.;K. Reinsch;Y. B. Jeon
    • Bulletin of the Korean Space Science Society
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    • 2003.10a
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    • pp.24-24
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    • 2003
  • We present preliminary results about the quasi-simultaneous near-infrared light curves of the long-period eclipsing polar V1309 Ori in the J, H, K', and K bands with almost complete orbital phase coverage using the CFHT-IR camera. The optical light curve in the V and R bands, obtained by 1.8m Telescope at BOAO, will be also presented. The shape and the amplitude of the orbital light curve change significantly from optical to near-infrared wavelengths.

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Recovering the Colors of Objects from Multiple Near-IR Images

  • Kim, Ari;Oh, In-Hoo;Kim, Hong-Suk;Park, Seung-Ok;Park, Youngsik
    • Journal of the Optical Society of Korea
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    • v.19 no.1
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    • pp.102-111
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    • 2015
  • This paper proposes an algorithm for recovering the colors of objects from multiple near-infrared (near-IR) images. The International Commission on Illumination (CIE) color coordinates of objects are recovered from a series of gray images captured under multiple spectral near-IR illuminations using polynomial regression. The feasibility of the proposed algorithm is tested experimentally by using 24 color patches of the Color Rendition Chart. The experimental apparatus is composed of a monochrome digital camera without an IR cut-off filter and a custom-designed LED illuminator emitting multiple spectral near-IR illuminations, with peak wavelengths near the red edge of the visible band, namely at 700, 740, 780, and 860 nm. The average color difference between the original and the recovered colors for all 24 patches was found to be 11.1. However, if some particular patches with high value are disregarded, the average color difference is reduced to 4.2, and this value is within the acceptability tolerance for complex image on the display.

MASS-LOSS RATES OF OH/IR STARS

  • Suh, Kyung-Won;Kwon, Young-Joo
    • Journal of The Korean Astronomical Society
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    • v.46 no.6
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    • pp.235-242
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    • 2013
  • We compare mass-loss rates of OH/IR stars obtained from radio observations with those derived from the dust radiative transfer models and IR observations. We collect radio observational data of OH maser and CO line emission sources for a sample of 1533 OH/IR stars listed in Suh & Kwon (2011). For 1259 OH maser, 76 CO(J=1-0), and 55 CO(J=2-1) emission sources, we compile data of the expansion velocity and mass-loss rate. We use a dust radiative transfer model for the dust shell to calculate the mass-loss rate as well as the IR color indices. The observed mass-loss rates are in the range predicted by the theoretical dust shell models corresponding to $\dot{M}=10^{-8}M_{\odot}/yr-10^{-4}M_{\odot}/yr$. We find that the dust model using a simple mixture of amorphous silicate and amorphous $Al_2O_3$ (20% by mass) grains can explain the observations fairly well. The results indicate that the dust radiative transfer models for IR observations generally agree with the radio observations. For high mass-loss rate OH/IR stars, the mass-loss rates obtained from radio observations are underestimated compared to the mass-loss rates derived from the dust shell models. This could be because photon momentum transfer to the gas shell is not possible for the physical condition of high mass-loss rates. Alternative explanations could be the effects of different dust-to-gas ratios and/or a superwind.