• Korean Journal of Microbiology
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• v.52 no.3
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• pp.383-387
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• 2016

In fission yeast, Schizosaccharomyces pombe, the cdc31 gene encodes a member of the conserved $Ca^{2+}$-binding centrin/CDC31 family, which is a component of spindle pole body. Here, we demonstrate that the S. pombe cdc31p is also a component of TREX-2 complex, which influences mRNA export from the nucleus to the cytoplasm. Repression of the cdc31 gene expression caused growth defect with accumulation of $poly(A)^+$ RNA in the nucleus. On the other hand, over-expression of cdc31 exhibited no defects of both growth and bulk mRNA export, but showed somewhat longer cell morphology. Yeast two-hybrid analysis showed that Cdc31 interacted with Sac3 and Pci2, the subunits of TREX-2 complex. These results suggest that S. pombe Cdc31 is also involved in mRNA export as a component of TREX-2 complex.

• Journal of The Korean Astronomical Society
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• v.33 no.2
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• pp.97-110
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• 2000

Planetary nebulae provide a direct way to probe elemental abundances, their distributions and their gradients in populations in nearby galaxies. We investigate bulge planetary nebulae in M 31 and M 32 using the strong emission lines, H$\alpha$, He I, [O III], [N II], [S II] and [Ne III]. From the [O III] 4363/5007 line ratio and the [O II] 3727/3729, we determine the electron temperatures and number densities. With a standard modeling procedure (Hyung, 1994), we fit the line intensities and diagnostic temperatures, and as a result, we derive the chemical abundances of individual planetary nebulae in M 31 and M 32. The derived chemical abundances are compared with those of the well-known Galactic planetary nebulae or the Sun. The chemical abundances of M 32 appear to be less enhanced compared to the Galaxy or M 31.

• Journal of The Korean Astronomical Society
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• v.34 no.2
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• pp.67-80
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• 2001

Chemical evolution of galaxies can be understood by studying the spatial distribution of heavy elements. We selected two nearby galaxies, M31 and M33 and investigated spectrum of their HII regions: a) the elec-tron densities have been derived from the [S II] 6717/6731 ratio along with the most recent atomic constants (Hyung & Aller 1996); b) the electron temperatures were determinated from the Pagel's empirical method. Nebula Model (Hyung 1994) has been employed to predict the spectral line intensities which gives the proper chemical abundances. The model would predict the line intensities correctly only when various input parameters such as the effective central star temperatures, gravity log g, model atmosphere as well as the geometry and the nebula physical condition are appropriate. Thus, the determination of chemical abundances of O, S, N of the two nearby galaxies M31 and M33 has been done, which shows a radial dependance of O/H and N/H: decrease with the distance, or increasing electron temperature due to the elemental deficiency. Abundances of M31 appear to be enhanced than those of M33.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.04b
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• pp.51-55
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• 2004

$CdS_{0.69}Se_{0.31}$ single crystal grown by sublimation method. Hall effect measurement were carried out by the Van der Pauw method. The measurement values under the temperature were found to be carrier density $n=1.95{\times}10^{23}m^{-3}$, Hall coeffcient $RH=3.21{\times}10^{-5}m^3/c$, conductivity ${\sigma}=362.41{\Omega}^{-1}m^{-1}$, and Hall mobility ${\mu}=1.16{\times}10^{-2}m^2/v.s.$ Heterojunction solar cells of $n-CdS_{0.69}Se_{0.31}/p-Cu_{2-x}S_{0.69}Se_{0.31}$ were fabricated by the substitution reaction. The open-circuit voltage, short-circuit currint density, fill factor and power conversion efficiency of $n-CdS_{0.69}Se_{0.31}/p-Cu_{2-x}S_{0.69}Se_{0.31}$ heterojunction solar cell under $80mW/cm^2$ illumination were found to be 0.41V, $19.5mA/cm^2$, 0.75 and 9.99%, respectivity.

• The Bulletin of The Korean Astronomical Society
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• v.26 no.1
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• pp.31.1-31.1
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• 2001

• Journal of the Korean institute of surface engineering
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• v.55 no.4
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• pp.196-201
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• 2022

This paper deals with anodic oxidation behavior of AZ31 Mg alloy in aqueous solutions containing various NaF concentrations from 0.01 M to 1 M. Three different voltage-time curves and anodic oxide formation behaviors appeared with concentration of NaF in deionized water. When NaF concentration is lower than 0.02 M, the voltage of AZ31 Mg alloy increased linearly and then reached a steady-state value more than 200 V, and large size pits and thin oxide layer were formed. When NaF concentration is between 0.05 M and 0.1 M, the voltage of AZ31 Mg alloy showed large periodic fluctuations of about 30 ~ 50 V around more than 200 V and large number of small particles were observed. If NaF concentration is higher than 0.2 M, PEO films can be formed without visible arcs under solution pH 6.5 ~ 7.5 by F^- ions without help of OH^- ions.

• Honam Mathematical Journal
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• v.31 no.2
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• pp.239-245
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• 2009

In this paper, we introduce the notions of m-semiopen sets and M-semicontinuous functions on spaces with minimal structures and study some properties of such notions. In particular, we investigate characterizations for the M-semicontinuous function and the relationship between M-continuity and M-semicontinuity.

• Journal of The Korean Astronomical Society
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• v.14 no.1
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• pp.1-11
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• 1981

Photoelectric drift scans of nearby galaxies, M106, M31 and M33 have been made at diurnal rate with the 61cm Cassegrain Reflector at Sobacksan Observing Station. Luminosity profiles of M106 and M31 show the asymmetries between east and west sides of the galaxies and the near side of each galaxy exhibits a larger B-V color than the far side. B-V color distribution in the central part of MI06 shows somewhat unusual feature of a blue center with red surrounding regions, and this is an opposite trend to the ordinary color distribution of most of external galaxies. B-V color of M31 is nearly constant in the central part of the galaxy while U-B color decreases as the distance from the center increases.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.41.2-41.2
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• 2014

Hierarchical merging scenario indicates that galaxies go through major and minor merger events during their formation and evolution. As a result of the merging, substructural features of remnants such as stellar stream are shown around a current galaxy system. To find evidence of stellar substructures on M31 system, we used the near-infrared images of JHK filters obtained from the Wide Field Camera (WFCAM) at UKIRT 3.8m. A total sky coverage is an area of about$ 4.5^{\circ}{\times}6^{\circ}$ around M31. Indeed, M31 system which consists of several satellite systems contains stellar substructures such as giant stellar stream, loops, and spurs. By analysing stellar populations on the near-infrared color-magnitude diagrams, we selected member star candidates of each stellar substructure, from which we map out spatial distribution of stars in the vicinity of M31 system. Here, we present spatial density distribution maps of stars on each substructure over the entire field of M31 system. Also, we discuss the possible origin of the substructures and the implications on the galaxy assembly process.

• Journal of The Korean Astronomical Society
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• v.37 no.4
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• pp.269-272
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• 2004

We present the first results of a wide field survey for planetary nebulae throughout M31 undertaken at the KPNO 0.9m telescope with the Mosaic camera. So far, images in [O III]$\lambda$5007 and its continuum filter have been analyzed. Our survey appears to be at least $90\%$ complete to about 2 mag below the peak of the planetary nebula luminosity function. Over 900 planetary nebulae candidates have been found within a 12 square degree area.