• International Journal of Highway Engineering
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• v.18 no.4
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• pp.37-45
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• 2016

PURPOSES : The objective of this study was to develop an impact resonance (IR) test procedure for thin disk-shaped specimens in order to determine the ${\mid}E^*{\mid}$ and phase angle values of various asphalt mixtures. METHODS : An IR test procedure was developed for evaluating thin disk-shaped specimens, in order to determine the dynamic modulus (${\mid}E^*{\mid}$) of various asphalt mixtures. The IR test method that was developed to determine the elastic modulus values of Portland cement concrete was evaluated, which method uses axisymmetric flexural vibration proposed by Leming et al. (1996). The IR tests were performed on three different mixtures of New York with varying nominal maximum aggregate sizes (NY9.5, NY19, and NY25) at six different temperatures ($10-60^{\circ}C$). The ${\mid}E^*{\mid}$ values obtained from the IR tests were compared with those determined by the commonly used AASHTO T342-11 test. RESULTS AND CONCLUSIONS : The IR test method was employed to determine the ${\mid}E^*{\mid}$ values of thin-disk-shaped specimens of various asphalt mixtures. It was found that the IR test method when used with thin disk-like specimens is a simple, practical, and cheap tool for determining the ${\mid}E^*{\mid}$ values of field cores. Further, it was found the ${\mid}E^*{\mid}$ values obtained from the IR tests using thin disk-like specimens were almost similar to those obtained using the AASHTO T342-11 test.

• Korean Journal of Optics and Photonics
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• v.30 no.4
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• pp.154-158
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• 2019

We have used a mid-IR (mid-infrared) continuous-wave (cw) optical parametric oscillator (OPO), developed previously and described in Ref. 12, to build a performance-evaluation setup for a mid-IR spectrometer. The used CW OPO had a wavelength tuning range of $ 2.5-3.6{\mu}m$ using a pump laser with a wavelength of 1064 nm and a fan-out MgO-doped periodically poled lithium niobate (MgO:PPLN) nonlinear crystal in a concentric cavity design. The OPO was combined with a near-IR integrating sphere and a Fourier-transform IR optical spectrum analyzer to build a performance-evaluation setup for mid-IR spectrometers. We applied this performance-evaluation setup to evaluating a mid-IR spectrometer developed domestically, and demonstrated the capability of evaluating the performance, such as spectral resolution, signal-to-noise ratio, spectral stray light, and so on, based on this setup.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.72.3-72.3
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• 2015

We present the mid-infrared (MIR) luminosity function (LF) of local (z < 0.3) star forming (SF) galaxies based on the AKARI's NEP-Wide Survey data. We utilized a combination of the NEP-Wide point source catalogue containing a large number (114,000) of infrared (IR) sources distributed over the wide (5.4 sq. deg) field and spectroscopic redshift (z) data for 1790 selected targets obtained by optical follow-up surveys with MMT/Hectospec and WIYN/Hydra. The AKARI's continuous $2{\sim}24{\mu}m$ wavelength coverage and the spectroscopic redshifts for sample galaxies enable us to derive accurate spectral energy distributions (SEDs) in the mid-infrared. We carried out SED-fit analysis and employed 1/Vmax method to derive the mid-IR (e.g., $8{\mu}m$, $12{\mu}m$, and $15{\mu}m$ rest-frame) luminosity functions. Our results for local galaxies from the NEP region generally consistent with various previous works for other fields over wide luminosity ranges. The comparison with the results of the NEP-Deep data implies the luminosity evolution from higher redshifts towards the present epoch. We attempted to fit our derived LFs to the double power-laws and present the resulting power indices. We also examined the correlation between mid-IR luminosity and total IR luminosity.

• Spatial Information Research
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• v.19 no.5
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• pp.37-46
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• 2011

In recent years, utilizations of satellite imagery have been extensively conducted in order to obtain accurate information on drought detection in spring season. This research also carried out utilization of satellite imagery through the various vegetation indices such as NDVI(Normalized Difference Vegeation Index), MSI(Moisture Stress Index), MidIR Index, II(Infrared Index) to find better methodology to detect drought phenomena, especially occurring in spring season. For this purpose, Landsat TM(Thematic Mapper) images were used and applied on the Yeong-cheon city. In this study, the characteristics of DN(Digital Number) for each vegetation index is analyzed, and the correlation analysis between indices and DN according to the number of days with no rain is performed. The results shows high correlation between NDVI and MSI and II with positive correlation on MSI, and negative correlation on II. This indicates the possibility for practical use of MSI, II indices with NDVI to obtain better credibility for detecting spring droughts.

• Current Optics and Photonics
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• v.6 no.1
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• pp.92-103
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• 2022

The development of midinfrared (mid-IR) quantum cascade lasers (QCLs) has enabled rapid high-contrast measurement of the mid-IR spectra of biological tissues. Several studies have compared the differences between the mid-IR spectra of colon cancer and noncancerous colon tissues. Most mid-IR spectrum classification studies have been proposed as machine-learning-based algorithms, but this results in deviations depending on the initial data and threshold values. We aim to develop a process for classifying colon cancer and noncancerous colon tissues through a deep-learning-based convolutional-neural-network (CNN) model. First, we image the midinfrared spectrum for the CNN model, an image-based deep-learning (DL) algorithm. Then, it is trained with the CNN algorithm and the classification ratio is evaluated using the test data. When the tissue microarray (TMA) and routine pathological slide are tested, the ML-based support-vector-machine (SVM) model produces biased results, whereas we confirm that the CNN model classifies colon cancer and noncancerous colon tissues. These results demonstrate that the CNN model using midinfrared-spectrum images is effective at classifying colon cancer tissue and noncancerous colon tissue, and not only submillimeter-sized TMA but also routine colon cancer tissue samples a few tens of millimeters in size.

• Journal of the Mineralogical Society of Korea
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• v.14 no.2
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• pp.119-127
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• 2001

FTIR spectroscopic study was undertaken on dickite and pyrophyllite with Si and Al cations in the far-infrared(Far-IR) and mid-infrared (Mid-IR) regions, respectively. Attempts were made to present bonding information and make assignments on the absorption bands of dickite in the Far-IR region. Dickites contain a small proportions or kaolinite or nacrite layers. FTIR can be used as a potential tool for characterizing the presence of mixed-layer with different polytypes of the kaolin minerals. There is no clear relationship between Hinckley index and crystallinity of dickite. Although pyrophyllite shows a strong OH stretching band at 3673-3676 $cm^{-1}$ / corresponding to an inner hydroxyl group, the weak band at $3645-3648 cm^{-1}$ seems to be due to the symmetric vibration if the symmetry of the structure is not ideal, probably due to the presence of trace Fe or mixture phases of 1Tc and 2M polytypes.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.995-997
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• 2005

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.355-357
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• 2017

For future space IR missions, such as SPICA, it is crucial to establish an experimental method for evaluating the performance of mid-IR detectors. In particular, the wavelength dependence of the sensitivity is important but difficult to be measured properly. We are now preparing a testing system for mid-IR Si:As/Si:Sb detectors on SPICA. We have designed a cryogenic optical system in which IR signal light from a pinhole is collimated, passed through an optical filter, and focused onto a detector. With this system, we can measure the photoresponse of the detector for various IR light using optical filters with different wavelength properties. We have fabricated aluminum mirrors which are adopted to minimize thermal distortion effects and evaluated the surface figure errors. The total wavefront error of the optical system is $1.3{\mu}m$ RMS, which is small enough for the target wavelengths ($20-37{\mu}m$) of SPICA. The point spread function measured at a room temperature is consistent with that predicted by the simulation. We report the optical performance of the system at cryogenic temperatures.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.82.2-82.2
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• 2011

Infra-Red Dark Clouds (IRDCs) seen silhouette against the bright Galactic background in mid-IR are a class of interstellar clouds that are dense and cold with very high column densities. While IRDCs are believed to be the precursors to massive stars and star clusters, individual IRDCs show diverse star forming activities within them. We report a remarkable example of such cloud, the IRDC at ${\Gamma}53.2^{\circ}$, and star formation activity in this cloud. The IRDC was previously identified in part as three separate, arcmin-size clouds in the catalogue of MSX IRDC candidates, but we found that the IRDC is associated with a long, filamentary CO cloud at 2 kpc from the Galactic Ring Survey data of $^{13}CO$ J = 1-0 emission, and that its total extent reaches ~ 30pc. The Spitzer MIPSGAL 24mm data show a number of reddened mid-IR sources distributed along the IRDC which are probably young stellar objects (YSOs), and the UWISH2 $H_2$ data (2.122mm) reveal ubiquitous out flows around them. These observations indicate that the IRDC is a site of active star formation with YSOs in various evolutionary stages. In order to investigate the nature of mid-IR sources, we have performed photometry of MIPSGAL data, and we present a catalogue of YSOs combining other available point source catalogues from optical to IR. We discuss the evolutionary stages and characteristics of YSOs from their IR colors and spectral energy distributions.

• Applied Science and Convergence Technology
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• v.23 no.6
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• pp.371-375
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• 2014

Diffusion coefficient of Fe in polycrystalline host ZnSe as a mid-IR gain medium has been measured in the annealing temperature ranges of 850 to $950^{\circ}C$. The synthesis of the samples was carried out in quartz ampoule in which the Fe thin film deposited by physical vapor evaporation method on the ZnSe. One can realize that the diffusion coefficient strongly depends on the surface active surfactants through the cleaning process and the substrate temperature during the thin film deposition leading to $2.04{\times}10^{-9}cm^2/s$ for $Fe^{2+}:ZnSe$. The Annealing temperature dependence of the Fe ions diffusion in ZnSe was used to evaluate the activation energy, $E_a$=1.39 eV for diffusion and the pre-exponential factor $D_0$ of $13.5cm^2/s$.