• Journal of Astronomy and Space Sciences
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• v.21 no.3
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• pp.167-180
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• 2004

We present HST NIC3 photometry of metal-rich globular clusters Palomar 6, Liller 1 and 47 Tuc (NGC 104). We discuss the interstellar reddening law for the HST NICMOS F110W/F160W photometric system which depends on the temperature of the source. The distance moduli and interstellar reddening values for Palomar 6 and Liller 1 are estimated by comparing the magnitudes and colors of RHB stars in the clusters with those of 47 Tuc. We obtain $(m-M)_0=14.48$mag and E(B-V)=1.34mag for Palomar 6 and $(m-M)_0=15.17$mag and E(B-V)=2.50 mag for Liller 1.

• Journal of the Korean Mathematical Society
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• v.54 no.2
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• pp.381-397
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• 2017

In this paper, we study surfaces in 3-dimensional Minkowski space in terms of certain type of their Gauss map. We give several results on these surfaces whose Gauss map G satisfies ${\square}G=f(G+C)$ for a smooth function f and a constant vector C, where ${\square}$ denotes the ChengYau operator. In particular, we obtain classification theorems on the rotational surfaces in ${\mathbb{E}}^3_1$ with space-like axis of rotation in terms of type of their Gauss map concerning the Cheng-Yau operator.

• Korean Journal of Crystallography
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• v.13 no.2
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• pp.86-90
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• 2002

The structure of N-(Diphenylmethylene)aminomethylphosphonate has been determined by X-ray diffraction methods. The crystal system is triclinic, space group P(equation omitted), unit cell constants, a＝8.967(2) (equation omitted), b＝9.309(2) (equation omitted), c＝ 10.981(2) (equation omitted), α＝101.42(2)°, β＝92.22(2)°, γ＝92.23(2)°, V=896.8(3) (equation omitted), T＝296 K, Z＝2, D/sub c/＝1.227 Mgm/sup -3/. The intensity data were collected on an Enraf-Nonius CAD-4 Diffractometer with graphite monochromated MoKα radiation (λ＝0.7107(equation omitted)). The molecular structure was solved by direct methods and refined by full-matrix least-squares to a final R＝7.3% for 979 unique observed F/sub o/>4σ(F/sub o/) refections and 209 parameters.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.62.2-62.2
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• 2019

The ADF-S (AKARI Deep Field - South) toward South Ecliptic Pole is one of the deep survey fields designed for the study of Extragalactic Background Light (EBL). The deep extragalactic survey was initiated by AKARI far-infrared deep observations. Other space missions (e.g., Euclid, NISS, SPHEREx) will perform the deep observations in the ADF-S. Based upon the recent optical survey with KMTNet, we can identify the optical counterparts for dusty star-forming galaxies such as ULIRG, DOG, SMG. Among them, the Dust-Obscured Galaxies (hereafter DOGs with f(24um)/f(R) > 1,000) in the heavily obscured system are expected to play an important role in the formation of most massive galaxies. We have newly discovered ~100 DOGs in ~12 sq. deg. of the ADF-S from our optical survey with KMTNet. We also confirmed that some of DOGs host the most luminous AGN for their black hole masses through the near-infrared spectroscopic follow-ups. Here, we report the properties of high-z hyperluminous DOGs in the ADF-S.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.78.1-78.1
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• 2019

Using a method to correct redshift space distortion (RSD) for individual galaxies, we mapped the real space distributions of galaxies in the Sloan Digital Sky Survey (SDSS) Data Release 7(DR7). We use an ensemble of mock catalogs to demonstrate the reliability of this extension, showing that it allows for an accurate recovery of the real-space correlation functions and galaxy biases. We also demonstrate that, using an iterative method applied to intermediate scale clustering data, we can obtain an unbiased estimate of the growth rate of structure $f\sigma_8$, which is related to the clustering amplitude of matter, to an accuracy of $\sim 10\%$. Applying this method to the Sloan Digital Sky Survey (SDSS) Data Release 7 (DR7), we construct a real-space galaxy catalog spanning the redshift range $0.01 \leq z \leq 0.2$, which contains 584,473 galaxies in the North Galactic Cap (NGC). Using this data we, infer $0.376 \pm 0.038$ at a median redshift z=0.1, which is consistent with the WMAP9 cosmology at $1\sigma$ level. By combining this measurement with the real-space clustering of galaxies and with galaxy-galaxy weak lensing measurements for the same sets of galaxies, we are able to break the degeneracy between $f$, $\sigma_8$ and $b$. From the SDSS DR7 data alone, we obtain the following cosmological constraints at redshift $z=0.1$ for galaxies.

• Applied Chemistry for Engineering
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• v.9 no.3
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• pp.372-376
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• 1998

Supported Pd($Pd/AlF_3$, $Pd/{\gamma}-Al_2O_3$) catalysts and solid-acid catalysts(${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$, $AlF_3$) were used to perform dechlorination of HCFC-142b(1-chloro-1,1-difluoroethane) in the presence of excess hydrogen. In the reactions the effects of reaction temperature, the mole ratio(r) of $H_2$ to HCFC-142b and the amount of supported Pd on dechlorination of HCFC-142b into HFC-143a(1,1,1-trifluoroethane) or HFC-152a(1,1-difluoroethane) were investigated. The experimental results showed that the conversion of HCFC-142b to product gases were 60% and 92%, respectively, and the selectivity to HFC-143a in the product gases were 58% and 64% for $Pd/AlF_3$ and $Pd/{\gamma}-Al_2O_3$ catalysts, respectively. On these catalysts an optimum reaction condition was found at $200^{\circ}C$ with the space time of reactant gases as 1.05 second and the mole ratio of $H_2$ to HCFC-142b as 3. Solid-acid catalysts were also tested at the same reaction condition. The results showed that the conversions of HCFC-142b to product gases were 12%, 8% and 7%, and the selectivities to HFC-152a were 94%, 92% and 90% for ${\gamma}-Al_2O_3$, ${\alpha}-Al_2O_3$ and $AlF_3$ catalysts, respectively.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.37.1-37.1
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• 2008

Space Science and Technology Laboratory at Kyung Hee University developed an 80cm Nasmyth telescope with the joint work of Space & Astronomy, Inc. It was set up at Muju county public astronomical observatory in Jeonlabuk-Do. Nasmyth focus system was selected for the telescope to use two focal points by a rotatable tertiary mirror. Focal ratios of the telescope are f10, f5 respectively. Support of the main mirror is made with Lasalle-system. This system uses 24-points in the back side of the mirror that are all resting on small counter-weights and side support is 10-points Boll link Flexible type with 2 Lasalle type. The mount is wheel & disk type Alt-Azimuth design using DC-servo motors. External high accuracy encoder has 47,600 sine-waves/rot. These encoders are used to make real-time corrections on all gearing errors.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.21-38
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• 1992

The present study was carried out to investigate morphologic changes in the corpus luteum of the pregnant rat by electron microscope after administration of prostaglandin F2$\alpha$(PGF2$\alpha$). Pregnant rates were treated with PGF2$\alpha$(1,500$\mu\textrm{g}$/rat) and their corpura lutea were observed morphologically. The results obtained in this study were summarized as follows ; 1. The weight of the ovaries and corpura lutea were decreased slightly at 8~24 hours after PGF2$\alpha$ administratin but no significant differences were observed. 2. The number of corpora lutea and luteal cells decreased slightly at 12~48 hours and 18~24 hours after PGF2$\alpha$ tretment but there were no signifciant differences between control and treatment. 3. The weight of uterus and the unmber of embryo decreased slightly at 96 hours and at 18~96 hours after PGF2$\alpha$ administration but no significant differences were obtained. 4. In the electron microscopic observatons, lipid droplets which are electron dense and appear in the cytoplasm moderately increased in number after PGF2$\alpha$ treatment. The lipid droplets were surrounded by mitochodria and appeared in the autophagic vacuoles. 5. Moderated and high electron dense mitochondria which are round or elongated in shape showed pleomorphism from 3 hours after PGF2$\alpha$ treatment. Destruction of tubular of vesicular cristae was observed at 6 hours after the treatment. Dense body and myelin figures in matrix of mitochondria were also appeared. 6. Well-developed smooth endoplasmic reticulum(sER) showed tubular or vesicular cisternae. A number of whorl membranes containing ribosomes, mitochondria and lipid droplets were observed at 1.5 hour after treatment. sER was abundant in luteal cells at 12 hours were treatment. 7. Well-developed Golgi pparatus appeared obviously 6 hours and more prominently at 12 hours. Those Golgi vesicles were remarkably dilated. 8. Generally, a few rough endoplasmic reticulum (rER) were appeared after treatment and cisternae showed slight dilatation. No differences among the treatments were observed. However, slight dilation of cisternae was observed at 1.5 hours after treatment. 9. Ribosomes composed of free and polyribosomes were abundant before treatment but polyribosomes were appeared at 12 to 24 hours after treatment. 10. Intercellular space were slightly extended at 3 hours and markedly extended at 12 hours. Numerous microvillous protrusions were observed at these times. Membranous multivesicular structures and autophagic vacuoles were also appeared in the intercellular space. 11. At 3 hours after the treatment, autophagic vacuoles appeared in the cytoplasm of the cell. They increased in number with time and were observed to transfer to the intercellular space. Lysosomal dense body appeared in the cytoplasm and the inclusion body was also observed in nucleus at 12 to 24 hours after treatment.

• Communications of the Korean Mathematical Society
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• v.32 no.1
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• pp.55-64
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• 2017

For -2 < ${\alpha}$ < ${\infty}$ and 0 < p < ${\infty}$, the $\mathcal{Q}_K$-type space is the space of all analytic functions on the open unit disk ${\mathbb{D}}$ satisfying $$_{{\sup} \atop a{\in}{\mathbb{D}}}{\large \int_{\mathbb{D}}}{{\mid}f^{\prime}(z){\mid}}^p(1-{{\mid}z{\mid}^2})^{\alpha}K(g(z,a))dA(z)<{\infty}$$, where $g(z,a)=log\frac{1}{{\mid}{\sigma}_a(z){\mid}}$ is the Green's function on ${\mathbb{D}}$ and K : [0, ${\infty}$) [0, ${\infty}$), is a right-continuous and non-decreasing function. For 0 < s < ${\infty}$, the space $\mathcal{Q}_s$ consists of all analytic functions on ${\mathbb{D}}$ for which $$_{sup \atop a{\in}{\mathbb{D}}}{\large \int_{\mathbb{D}}}{{\mid}f^{\prime}(z){\mid}}^2(g(z,a))^sdA(z)<{\infty}$$. Boundedness and compactness of composition operators $C_{\varphi}$ acting on $\mathcal{Q}_K$-type spaces and $\mathcal{Q}_s$ spaces is characterized in terms of the norms of ${\varphi}^n$. Thus the author announces a solution to the problem raised by Wulan, Zheng and Zhou.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.3
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• pp.375-388
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• 2019

Accurate evaluation of sea-to-air $CO_2$ flux and its variability is crucial information to the understanding of global carbon cycle and the prediction of atmospheric $CO_2$ concentration. $fCO_2$ observations are sparse in space and time in the East Sea. In this study, we derived high resolution time series of surface $fCO_2$ values in the southwest East Sea, by feeding sea surface temperature (SST), salinity (SSS), chlorophyll-a (CHL), and mixed layer depth (MLD) values, from either satellite-observations or numerical model outputs, to three machine learning models. The root mean square error of the best performing model, a Random Forest (RF) model, was $7.1{\mu}atm$. Important parameters in predicting $fCO_2$ in the RF model were SST and SSS along with time information; CHL and MLD were much less important than the other parameters. The net $CO_2$ flux in the southwest East Sea, calculated from the $fCO_2$ predicted by the RF model, was $-0.76{\pm}1.15mol\;m^{-2}yr^{-1}$, close to the lower bound of the previous estimates in the range of $-0.66{\sim}-2.47mol\;m^{-2}yr^{-1}$. The time series of $fCO_2$ predicted by the RF model showed a significant variation even in a short time interval of a week. For accurate evaluation of the $CO_2$ flux in the Ulleung Basin, it is necessary to conduct high resolution in situ observations in spring when $fCO_2$ changes rapidly.