• Journal of Photoscience
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• v.4 no.3
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• pp.121-125
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• 1997

The 77 K emission and excitation, and room-temperature visible spectra of cis[Cr(cyclam)Br$_2$]Br (cyclam=1,4,8,11-tetraazacyclotetradecane) are reported. The mid- and far-infrared spectra at room-temperature are also measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. It is found that nitrogen atoms of the cyclam ligand have strong $\sigma$-donor characters, but bromide ligand has weak $\sigma$- and $\pi$-donor properties toward chromium(III) ion. The zerophonon line in the excitation spectrum splits into two components by 172 cm$^{2-}$, and the large $^2E_g$ splitting can be reproduced by the ligand field theory.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.159-161
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• 2015

We have carried out optical spectroscopic measurements of emission lines for a sample of Galactic planetary nebulae with Wolf-Rayet (WR) stars and weak emission-line stars (wels). The plasma diagnostics and elemental abundance analysis have been done using both collisionally excited lines (CELs) and optical recombination lines (ORLs). It was found that the abundance discrepancy factors ($ADF{\equiv}ORL/CEL$) are closely correlated with the difference between temperatures derived from forbidden lines and those from $He\;{\small{I}}$ recombination lines, implying the existence of H-deficient materials embedded in the nebula. The $H{\beta}$ surface brightness correlations suggest that they might be also related to the nebular evolution.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.145-148
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• 2015

Young Galactic supernova remnants (SNRs) are where we can observe closely supernova (SN) ejecta and their interaction with the circumstellar/interstellar medium. They also provide an opportunity to explore the explosion and the final stage of the evolution of massive stars. Near-infrared (NIR) emission lines in SNRs mostly originate from shocked dense material. In shocked SN ejecta, forbidden lines from heavy ions are prominent, while in shocked circumstellar/interstellar medium, [Fe II] and $H_2$ lines are prominent. [Fe II] lines are strong in both media, and therefore [Fe II] line images provide a good starting point for the NIR study of SNRs. There are about twenty SNRs detected in [Fe II] lines, some of which have been studied in NIR spectroscopy. We will review the NIR [Fe II] observations of SNRs and introduce our recent NIR spectroscopic study of the young core-collapse SNR Cas A where we detected strong [P II] lines.

• Bulletin of the Korean Chemical Society
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• v.14 no.1
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• pp.118-122
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• 1993

The 77 K luminescence and excitation spectra, room-temperature FT-infrared and visible absorption spectra of a newly prepared complex cis-[Cr(cyclam)(pn)]$(ClO_4)_3$, where cyclam and pn represent 1,4,8,11-tetraazacyclotetradecane and 1,2-propanediamine respectively, have been measured. Absorption maximum of the first spin-allowed transition in the electronic absorption spectra of cis-[Cr(cyclam)(pn)]$^{3+}$ and cis-[Cr(cyclam)(en)]$^{3+}$ appears at nearly the same position. The two spin-allowed and six spin-forbidden electronic transitions are assigned from the visible absorption and excitation spectra. It is also shown that the zero phonon line in the excitation spectrum splits into two components by 50 cm$^{-1}$.

• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.81-84
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• 1999

The emission and excitation spectra of [Cr(NH3)5(imH)](ClO4)3·H2O (imH=imidazole) taken at 77 K are reported. The 298 K visible and far-infrared spectra are also measured. The vibrational intervals of the electronic ground state are extracted from the far-infrared and emission spectra. The ten electronic bands due to spin-allowed and spin-forbidden transitions are assigned. Using the observed transitions, a ligand field analysis has been performed to determine the bonding properties of coordinated imidazole in the title chromium(Ⅲ) complex. It is confirmed that nitrogen atom of the imidazole ligand has a medium it-acceptor property toward chromium(Ⅲ) ion. The zero-phonon line in the excitation spectrum splits into two components by 181 cm-1, and the large 2Eg splitting can be reproduced by the ligand field theory.

• The Journal of the Korea Contents Association
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• v.9 no.12
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• pp.113-120
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• 2009

Currently the verbal abuse in text message over on-line game is so serious. However we do not have any effective policy or technical tools yet. Till now in order to cope with this problem, the online game service providers have accumulated a set of forbidden words and applied this list on the textual word used in on-line game, which is called 'Swear filter'. But young on-line game players easily avoid this filtering method by coining another words which is not kept in the list. Especially Korean is very easy to make new variations of a vulgar word. In this paper, we propose one smart filtering algorithm to identify newly coined profanities. Important features of our method include the canonical form transformation of coined profanities, semi-global alignment between in the level of consonant and vowel units. For experiment, we have collected more than 1000 newly coined vulgar words in on-line gaming sites and tested these word against our methods. where our system have successfully filtered more than 90% of those newly coined vulgar words.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.73.2-73.2
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• 2011

We present a new database of absorption and emission-line measurements based on the entire spectral atlas from the Sloan Digital Sky Survey (SDSS) 7th data release of galaxies within a redshift of 0.2. Our work makes use of the publicly available penalized pixel-fitting(pPXF) and gas and absorption line fitting (gandalf) IDL codes, aiming to improve the existing measurements for stellar kinematics, the strength of various absorption-line features, and the flux and width of the emissions from different species of ionized gas. Our fit to the stellar continuum uses both standard stellar population models and empirical templates obtained by combining a large number of stellar spectra in order to fit a subsample of high-quality SDSS spectra for quiescent galaxies. Furthermore, our fit to the nebular spectrum includes an exhaustive list of both recombination and forbidden lines. Foreground Galactic extinction is implicitly treated in our models, whereas reddening in the SDSS galaxies is included in the form of a simple dust screen component affecting the entire spectrum that is accompanied by a second reddening component affecting only the ionised gas emission. Most notable of our work is that, we provide quality of the fit to assess reliability of the measurements. The quality assessment can be highly effective for finding new classes of objects. For example, based on the quality assessment around the Ha and [NII] nebular lines, we found approximately 1% of the SDSS spectra which classified as "galaxies" by the SDSS pipeline are in fact type I Seyfert AGN.

• Journal of the Korean earth science society
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• v.43 no.3
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• pp.351-366
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• 2022

We investigated the kinematic activity of the Type II Seyfert galaxy Mrk 1 based on H𝛽 and [O III] 5007 extracted from the MR 1 grism spectra observed with the OASIS attached to the CFHT 3.6 m telescope. The [O III] forbidden Gaussian line profiles exhibited asymmetric features with an excess of the blue component: (1) strongest at a distance of about 960 pc from the galaxy center, and (2) a wider line width of about ~900 km s^-1 in the NS direction of the center. The velocity distributions in the spectral images showed blue or approaching flow motion in the NE zone, while receding in the SW zone, implying the counter-clockwise rotation. The radial velocity data showed that the center of the AGN region appears to be blocked by gas-dust approaching toward the Earth.

• Journal of the Korean Chemical Society
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• v.39 no.7
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• pp.501-507
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• 1995

The electronic structure of cis-$[Cr(cyclam)Cl_2]Cl$ has been investigated by the emission and excitation spectroscopy at 77K, and infrared and visible spectroscopy at room temperature. The ten electronic transitions due to spin-allowed and spin-forbidden are assigned. The zero-phonon line in the excitation spectrum splits into two components by $139\;cm^{-1}$, and it can be reproduced by modern ligand field theory. According to the results of ligand field analysis, we can confirm that nitrogen atoms of the cyclam ligand have a strong ${\sigma}$-donor character, but chloride ligand has weak ${\sigma}-$ and ${\pi}-$donor properties toward chromium(III) ion.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.261-262
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• 2012

The aim of this research is to reveal the spatial distribution of the star formation activity of nearby galaxies by comparing CO molecular emission lines with the large area observation in far-infrared (FIR) lines. We report the imaging observations of NGC 253 by FIR forbidden lines via FIS-FTS and CO molecular lines from low to high excitation levels with ASTE, which are good tracers of star forming regions or photo-dissociation regions, especially spiral galaxies, in order to derive the information of the physical conditions of the ambient interstellar radiation fields. The combination of spatially resolved FIR and sub-mm data leads to the star formation efficiency within galaxy. The ratio between the FIR luminosity and molecular gas mass, $L_{FIR}/M_{H_2}$, is expected to be proportional to the number of stars formed in the galaxy per unit molecular gas mass and time. Moreover the FIR line ux shows current star formation activity directly. Furthermore these can be systematic and statistical data for star formation history and evolution of spiral galaxies.