• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.111.1-111.1
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• 2011

We present near-IR imaging polarimetry of the observed $5{\times}9$ fields (${\sim}39'{\times}69'$) in the Large Magellanic Cloud (LMC), using the InfraRed Survey Facility (IRSF). We obtained polarimetry data in J, H, and Ks bands using the JHKs-simultaneous imaging polarimeter SIRPOL. We measured Stokes parameters of point-like sources to derive the degree of polarization and the polarization position angle. We show a polarization vector map in the reduced 45 fields and the statistical distribution of the polarization degrees and angles. This poster presents the preliminary results to show the physical properties of the magnetic field in the observed LMC regions.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.163-167
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• 2015

We have carried out integral field unit (IFU) spectroscopy of $H{\alpha}$, [$N{\small{II}}$] and [$O{\small{III}}$] emission lines for a sample of Galactic planetary nebulae (PNe) with Wolf-Rayet (WR) stars and weak emission-line stars (wels). Comparing their spatially-resolved kinematic observations with morpho-kinematic models allowed us to disentangle their three-dimensional gaseous structures. Our results indicate that these PNe have axisymmetric morphologies, either bipolar or elliptical. In many cases the associated kinematic maps for the PNe around hot central stars also reveal the presence of so-called fast low-ionization emission regions.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.58.3-59
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• 2018

We investigate velocity oscillations in a solar quiet region by using the spectral data of the $H{\alpha}$ and Ca II $8542{\AA}$ lines. The data were acquired by the Fast Imaging Solar Spectrograph installed at the 1.6 m Goode Solar Telescope of Big Bear Solar Observatory. According to Chae & Litvinenko (2018)'s theoretical work, there is a correlation between dominant period of the oscillations and the temperature of the temperature minimum region in a non-isothermal atmosphere. In our study, we measure the temporal variations of the intensity and the line of sight Doppler velocity, and find out the relations between the intensity and dominant period of the oscillations. In addition, we investigate oscillations in a few distinct regions and discuss regional characteristics of the oscillations.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.52.3-53
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• 2018

We compare vertical profiles of the extraplanar $H{\alpha}$ emission to those of the UV emission for 38 nearby edge-on late-type galaxies. It is found that detection of the "diffuse" extraplanar dust (eDust), traced by the vertically extended, scattered UV starlight, always coincides with the presence of the extraplanar $H{\alpha}$ emission. A strong correlation between the scale heights of the extraplanar $H{\alpha}$ and UV emissions is also found; the scale height at $H{\alpha}$ is found to be ~0.74 of the scale height at FUV. Our results may indicate the multiphase nature of the diffuse ionized gas and dust in the galactic halos. The existence of eDust in galaxies where the extraplanar $H{\alpha}$ emission is detected suggests that a larger portion of the extraplanar $H{\alpha}$ emission than that predicted in previous studies may be caused by $H{\alpha}$ photons that originate from H II regions in the galactic plane and are subsequently scattered by the eDust. This possibility raise an advantage in studying the extraplanar diffuse ionized gas. We also find that the scale heights of the extraplanar emissions normalized to the galaxy size correlate well with the star formation rate surface density of the galaxies. The properties of eDust in our galaxies is on a continuation line of that found through previous observations of the extraplanar polycyclic aromatic hydrocarbons emission in more active galaxies known to have galactic winds.

• Journal of Korean Society for Atmospheric Environment
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• v.32 no.5
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• pp.485-500
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• 2016

We examined acidity state of inorganic aerosol and oxidation state of organic aerosol by High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) at Baengnyeong Super site from Jan 2012 to Dec 2013. Additionally, we carried out the analysis for the aerosol component group of organic matter ($C_xH_y$, $C_xH_yO_1$, $C_xH_yO_z$, $C_xH_yO_zN_p$) and elemental composition to calculate H/C, O/C, N/C, OM/OC and identify the oxidation state. The aerosol chemical composition in this study is dominated by sulfate ($SO_4{^{2-}}$), nitrate ($NO_3{^-}$) plays a smaller role in aerosol acidity. Ammonium ($NH_4{^+}$) was found in a formation of $(NH_4)_3H(SO_4)_2$. However, the binding formations of $NH_4NO_3$ and $NH_4Cl$ increase in the winter. $C_xH_yO_1$ indicating the oxidized state of $PM_{1.0}$ has the highest ratio of 41% while $C_xH_y$ indicating the non-oxidized state has a lower ratio of 36%, meaning that the oxidation level of $PM_{1.0}$ in Baengnyeong Island is high. The ratio between H/C and O/C was 1.33 and 0.78 respectively, showing the characteristic of LV-OOA (Low volatility-Oxygenated Organic Aerosol). Acidic and oxidized aerosols sampled during this field study were largely anthropogenic in origin from Chinese continent and photochemically aged.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.37.4-38
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• 2016

Based on the $850{\mu}m$ dust continuum data from James Clerk Maxwell Telescope (JCMT)/SCUBA-2, we compare overall properties of Planck Galactic Cold Clumps (PGCCs) in the ${\lambda}$ Orionis cloud with PGCCs in other molecular clouds, Orion A and Orion B. The Orion A and Orion B clouds are well known active star-forming region, while, ${\lambda}$ Orionis cloud has a different environment associating with prominent OB associations and a giant H II region. PGCCs in the ${\lambda}$ Orionis cloud have higher dust temperatures (Td~16.08 K) and lower values of dust emissivity (${\beta}{\sim}1.65$) than Orion A and Orion B clouds. In addition, we found the lowest detection rate (16 %, 8 out of 50) of PGCCs at $850{\mu}m$ in the ${\lambda}$ Orionis cloud while among three regions; Orion A and Orion B clouds show much higher detection rates of ~ 76 % (23 out of 30) and 56 % (9 out of 16), respectively. The detected 8 PGCCs in the ${\lambda}$ Orionis cloud have substructures and we identified 15 cores. The cores also show much lower median values of size (~0.08 pc), column density (~ ), number density (~ ), and mass (~ ) compared with other cores in the Orion A and Orion B clouds. These core properties in the ${\lambda}$ Orionis cloud can be attributed to the compression and external heating by the nearby H II region, which may prevent the PGCCs from forming gravitationally bound structures and eventually disperse them. These results well present the negative stellar feedback to core formation.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1633-1637
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• 2006

We demonstrate a selective vapor-phase deposition of conductive poly(3,4-ethylenedioxythiophene) (PEDOT) thin films on patterned $FeCl_3$. The PEDOT thin films were grown on various substrates by using the vapor-phase polymerization of ethylenedioxythiophene (EDOT) with $FeCl_3$ catalytic layers at 325 K. The selective deposition of the PEDOT thin films using vapor-phase polymerization was accomplished with patterned $FeCl_3$ layers as templates. Microcontact printing was done to prepare patterned $FeCl_3$ on polyethyleneterephthalate (PET) substrates. The selective vapor-phase deposition is based on the fact that the PEDOT thin films are selectively deposited only on the regions exposing $FeCl_3$ of the PET substrates, because the EDOT monomer can be polymerized only in the presence of oxidants, such as $FeCl_3$, Fe($CIO_4$), and iron(II) salts of organic acids/inorganic acids containing organic radicals.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.171-176
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• 1985

The structure of natural vegetation and soil condition in bog area of Woopo, Changnyeung, South Korea were observed. The vegetations in the investigated area could be classified into two groups; a typical bog vegetation with dominant species of Eleocharis mamillats, Acorus calamus and Persicaria hostatosagittata and the transitional vegetation of three neighboring areas. Interspecific correlation in the investigated area was very close. In the typical bog vegetatiion regions (region II, III, V, VI, VII, VIII and X) soil pH, field moisture capacity, available P content and exchangeable K were moderate. But, In the transitiional area I, with the highest humus content, field moisture capacity and exchangeable K Salix gracilistyla was dominant. In the region IV with the lowest humus and a ailable P content and with high soil pH Geophyta was a major component species. Also Acorus region IX with the lowest content of exchangeable K Therophyta was dominant and plant species was diverse due to weak water influence. The vegetation structure of the region IX was most different from that of the whole vegetation.

• Journal of the Korean Chemical Society
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• v.37 no.2
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• pp.237-243
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• 1993

The primary and secondary structure of the 5S rRNA isolated from Xanthomonas celebensis were determined by enzymatic and chemical degradation methods. It consists of 119 nucleotides and contains no modified nucleosides. As with the 5S rRNAs of X. maltophilia and X. citri, it contains an additional uridine residue on the 5'-terminus. Its secondary structure was almost identical to the models previously proposed by us for the 5S rRNA of two Xanthomonas species. Its secondary structure consists of five helices, five loops and two bulges. The tertiary interactions in the 5S rRNA molecule were analyzed by Fe(II)-EDTA treatment and hybridization method using deoxyhexamer. From the fact that some adenine residues in loop M, region $I_1-C$, loop $H_1$, and loop $H_2$ become susceptible to diethylpyrocarbonate when the 5S rRNA was hybridized with deoxyhexamer complementary to the sequence $U_{35}CCCAU_{40}$ and that some nucleotide residues in loop M, loop $H_1$ and region $D-I_2$ become resistant Fe(II)-EDTA cleavage in the presence of $Mg^{2+}$, it is presumed that loops $H_1$ and $H_2$ interact with loop M in some way. In the tertiary interaction, the regions $I_1-C$ and $D-I_2$ seem to act as hinges in folding the stems $B-I_1-C$ and $D-I_2-E.$ It was found that loop $H_1$ changes into a smaller loop of three bases by forming noncanonical A : C base-pairs ih acidic environment.

• Journal of Radiation Protection and Research
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• v.30 no.3
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• pp.121-130
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• 2005

Geographical Information System(GIS) was established to display the calculation results which show the concentration change with time and regions in case of an accidental release of radionuclides from Kori Nuclear Power Plants. GIS included the commercial program, ArcView(ESRI), and a basic digital map of 1:5000 scale lot 20km by 20km around Kori area. The object for the presentation was $^{131}I$ concentration in rice which is one of staple foodstuffs. Provided by deposited $^{131}I$ concentrations, ECOREA-II code computed the $^{131}I$ concentration of the soil and the plant in the area divided by In unit cells in total, in which the concentrations also varied with time. The results were introduced into the attributed data of previously designed polygon cells in ArcView. In order to display the concentration change with time by monotonic color, the RGB value for ArcView color lamp was controlled. This display definitely helped the concentration change around Kori area be acceptable to public.