• Journal of the Korean earth science society
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• v.38 no.1
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• pp.1-10
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• 2017

The symbiotic star AG Peg is a nebulous binary system that consists of giant star (GS) and white dwarf (WD). We investigated the HI Balmer emission lines of the symbiotic nova AG Peg, observed in 1998, 2001, and 2002 at Lick Observatory. The $H{\alpha}$ and $H{\beta}$ line profiles consist of blue-shifted, red-shifted, and broad components of which intensities and width showed notable changes. The HI emission line profiles that represent the kinematics of the gaseous nebula appear to be mainly from an accretion disk in relatively large radius from the WD. Considering the line of an observer's sight, both GS and WD are located at the sky plane side by side during the 1998 observation, while the WD is in front of GS during 2002 but the WD in rear during 2001. Such a relative position and the spectral line intensity variation imply that a fairly constant outflow occurs into WD from GS which caused to maintain the rotating thick accretion disk structure responsible for the observed spectral lines.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.720-725
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• 2004

We proposed new arc-type wheel profiles to improve severe flange wear of conventional wheel profile coned 1:40. We designed many candidate wheel profiles and analyzed the geometric characteristics, dynamic performance and stress at contact points to draw out the final profiles. From the analysis result, we chose two cases of profiles and applied to wheels of test train. Tests carried out in service line to analyze the dynamic performance and verify the wear reduction for two cases of profiles. Test results shows the equal level of dynamic performance and the improvement of wheel flange wear compared with the conventional wheel profile.

• Journal of The Korean Astronomical Society
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• v.53 no.2
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• pp.35-42
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• 2020

We analyze high dispersion emission lines of the symbiotic nova AG Pegasi, observed in 1998, 2001, and 2002. The Hα and Hβ lines show three components, two narrow and one underlying broad line components, but most other lines, such as H_I, He_I, and He_II lines, show two blue- and red-shifted components only. A recent study by Lee & Hyung (2018) suggested that the double Gaussian lines emitted from a bipolar conical shell are likely to form Raman scattering lines observed in 1998. In this study, we show that the bipolar cone with an opening angle of 74°, which expands at a velocity of 70 km s^-1 along the polar axis of the white dwarf, can accommodate the observed double line profiles in 1998, 2001, and 2002. We conclude that the emission zone of the bipolar conical shell, which formed along the bipolar axis of the white dwarf due to the collimation by the accretion disk, is responsible for the double Gaussian profiles.

• Journal of Astronomy and Space Sciences
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• v.14 no.1
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• pp.24-32
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• 1997

We have calculated the velocity distribution of wind driven by Alfven waves. The assumed initial number density of wind can affect the line profiles because it produces the change in the velocity distribution under the mass conservation. Initial density $N_O=5.5{\times}10^{12}/cm^3$ is chosen for a proper initial density from the observation by Schroder(1986). The wind models for $N_O=10^9,10^{10},10^{11},5.5{\times}10^{12}/cm^3$ are calculated at ${phi}$=0.06 and ${phi}$=0.78. The line profiles for lower initial density show the strong emissions and narrow absorptions because of their steeper velocity gradients.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1653-1655
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• 1998

In this paper, measurement and analysis of ELF electric and magnetic fields in the vicinity of 22.9[kV] distribution line have been performed. The height of measuring point from the earth's surface was 1[m], and the distance between the device and the operator was more than 3[m]. The experiments have been carried out by lateral profile, and we have made use of FIELDS program for the sake of comparision the experimental data with the theoretical value. Electric and magnetic fields intensity were strong under a distribution line, and were inversely proportional to lateral distance. The profiles of electric field were M shape and those of magnetic field were $\cap$ shape. Electric and magnetic fields intensity were increased with increasing the measurement height.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.4
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• pp.347-354
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• 2012

Using a single-line pulsed laser beam is well known as a useful noncontact method to generate a directional surface acoustic wave. In this method, different laser beam energy profiles produce different waveforms and frequency characteristics. In this paper, we considered two typical kinds of laser beam energy profiles, Gaussian and square-like, to find out a difference in the frequency characteristics. To achieve this, mathematical models were proposed first for Gaussian laser beam profile and square-like respectively, both of which depended on the laser beam width. To verify the theoretical models, experimental setups with a cylindrical lens and a line-slit mask were respectively designed to produce a line laser beam with Gaussian spatial energy profile and square-like. The frequency responses of the theoretical models showed good agreement with experimental results in terms of the existence of harmonic frequency components and the shift of the first peak frequencies to low.

• Journal of The Korean Astronomical Society
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• v.33 no.2
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• pp.81-88
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• 2000

The international ultraviolet explorer (IUE) spectra of a low dispersion $\~6{\AA}$, have been investigated for two Seyfert 1 galaxies, Mrk 335 and NGC 4051, well known for the line variability. The electron densities of broad line region (BLR) of these variable Seyfert 1 galaxies have been derived, which showed a non-linear abrupt variation from $10^8$ to $10^{10} cm-3$ within a month. We also found the excitation (or temperature) changes in the Mrk 335 BLR from the IUE broad line profiles analysis, but no such evidence in the NGC 4051. The large amount of mass inflow activity through the bar or spiral structure of host galaxies, may trigger the density change in BLR and emission line variability for both objects. Mass of the giant black holes appear to be order of $10^7\;M_{\bigodot}$ for both variable Seyfert l's.

• The Bulletin of The Korean Astronomical Society
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• v.21
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• pp.8.1-8.1
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• 1996

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.129.2-129.2
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• 2009

• The Bulletin of The Korean Astronomical Society
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• v.36 no.2
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• pp.115.1-115.1
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• 2011

We analyzed the line profiles of the planetary nebula (PN) NGC 7009 secured with the Keck I HIES and BOES's spectral data. The 5 positions were taken over the nebular image, 4 points on the bright rim plus 1 point at the central position. The covered spectral wavelength range was $3250{\AA}-8725{\AA}$ in these observations. We decomposed the lines of HI, HeI, HeII, CII, NIII, [ClIII], [NII], [OII], [OIII], [SII], [SIII], [ClIII], and [ArIII] using the IRAF and StarLink/Dipso. After correcting the Earth's movement and the PN's radial velocities, -48.6 & -48.9 km/s, respectively, for the Keck & BOES, we produced the line profiles in a velocity scale. The zero velocity at each line profile clearly indicates which part of the components is approaching or receding, giving a general information of the kinematical structure. Almost all of the low-to-medium excitation lines, such as [NII], [SII], [O III], and [ArIII], secured at the central position and four positions along the major & minor axes, showed 3 components, double peak + a wide wing component, suggesting the fast outflow structures are present. The overall geometry is a prolate shell which also has a fainter outer shell in the halo zone, but there appears to be some peculiar sub-structures inside the main shell. The high excitation He I, HeII, NIII lines which might be formed close to the inner boundary of the shell show unusual features, completely different from the other lines. The HeII and these high excitation lines may be indicative of a relative recent fast outflow from the central star and the permitted lines such as NIII might be affected by the innermost structure. We discuss a possible presence of a jet-like fast outflow structure in an out-flow axis different from the main axis of the spheroid shell.