• The Bulletin of The Korean Astronomical Society
• /
• v.20
• /
• pp.34.1-34.1
• /
• 1995

• The Bulletin of The Korean Astronomical Society
• /
• v.16
• /
• pp.19.3-20
• /
• 1991

• The Bulletin of The Korean Astronomical Society
• /
• v.40 no.1
• /
• pp.78.4-79
• /
• 2015

We present the spatially resolved kinematics of ionized gas and stars along the major axis of 9 pseudo bulge galaxies. Using the high quality long-slit spectra obtained with the FOCAS at the Subaru telescope, we measured the flux, velocity, and velocity dispersion of the [OIII] and $H{\beta}$ lines to determine the size of the narrow-line region, rotation curve, and the radial profile of velocity dispersions. We compare ionized gas kinematics and stellar kinematics to investigate whether ionized gas shows any signs of outflows and whether stars and ionized gas show the same sigma-dip feature (i.e., decrease of velocity dispersion) at the very center.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2001.10a
• /
• pp.58-61
• /
• 2001

An implicit finite element formulation for axisymmetric tube hydroforming is investigated. In order to describe normal anisotropy of the tube, Hill's non-quadratic yield function is employed. The frictional contact between die and tube and frictionless contact between tube and fluid are considered using the mesh-normal vector computed from finite element mesh of the tube. In order to verify the validity of the developed finite element formulation, the axisymmetric tube bulge test is simulated and simulation results are compared with experimental measurements. In the axisymmetric tube hydroforming process, an optimal hydraulic curve is pursued by performing the simulation with various internal pressures and axial forces.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2003.04a
• /
• pp.63-66
• /
• 2003

Thermoforming of fiber reinforced thermoplastic (FRTP) braided tubes was studied as a new forming technique. FRTP braided tubes with four plies are fabricated by the pressure bonding method are used in thermoforming. Bulge forming, bending process, pipe fittings and FE analysis are carried out in this study. In bulge forming the composite tube can be expanded up to about two times initial diameter. The suggested bending process can be obtained bent products with various bending radii. In pipe fitting it is possible to fabricate T-shape fitting, cross fitting and two-branch fitting. These results exhibit developed forming processes become useful processes for textile composite tubes.

• Journal of The Korean Astronomical Society
• /
• v.32 no.2
• /
• pp.83-89
• /
• 1999

We have conducted a V, I, J, and H surface photometry of a barred galaxy NGC 4314 to analyze the morphology and luminosity distribution of the galaxy. By applying a semi two-dimensional profile decomposition method, we derived the luminosity fractions and the scale lengths of the three distinct components, bulge, disk, and bar: $L_b {\approx}0.35,\;L_d{\approx}0.35,\;L_{bar}{\approx}0.30,\;r_e{\approx}22",\;r_o {\approx} 50"$, and a $\approx$ 60". The bulge of NGC 4314 seems to be triaxial due to the isophotal twists but its luminosity distribution is well approximated by the $r^{1/4}$-law.

• Journal of The Korean Astronomical Society
• /
• v.47 no.4
• /
• pp.153-158
• /
• 2014

I show that the standard microlensing technique to measure the angular radius of a star using color/surface-brightness relations can be inverted, via late-time proper motion measurements, to calibrate these relations. The method is especially useful for very metal-rich stars because such stars are in short supply in the solar neighborhood where other methods are most effective, but very abundant in Galactic bulge microlensing fields. I provide a list of eight spectroscopically identified high-metallicity bulge stars with the requisite finite-source effects, seven of which will be suitable calibrators when the Giant Magellan Telescope comes on line. Many more such sources can be extracted from current and future microlensing surveys.

• The Bulletin of The Korean Astronomical Society
• /
• v.38 no.2
• /
• pp.70.1-70.1
• /
• 2013

We present long-term optical to NIR data of the tidal disruption object, Swift J1644+57. The data were obtained with CQUEAN, UKIRT WFCAM observations. We analyze the morphology of the host galaxy of this object and decompose the bulge component using high resolution HST WFC3 images. We conclude that the host galaxy is bulge dominant. We also estimate the multi-band fluxes of the host galaxy through the light curves based on the long-term observational data. We fit the SED models to the multi-band fluxes of the host galaxy and determine its stellar mass. Finally, we estimate the mass of the central super massive black hole which is thought to be the main role of the tidal disruption event. The estimated stellar mass and black hole mass are $10^{9.1}M_{\odot}$, $10^{6.8}M_{\odot}$ respectively. We compare our results to other results that have studied before.

• Journal of the Korean Society of Safety
• /
• v.12 no.3
• /
• pp.52-59
• /
• 1997

Hill's anisotropy theory and isotropy theory under the deformed profile assumed two separate cases(that is circular and ellipitical) are applied to predict the plastic deformation characteristics of bulge, the strain and polar height under instability condition, using thin square diaphragms of stainless steel, mild steel, brass, copper and aluminum. In this study it was found that the pressure-polar height curves, and the polar height-the polar radius of curvature curve, under anisotropy theory and isotropy theory, assuming a circle profile, agree well with the experimental results, and the equivalent strains of the instability condition under anisotropy theory are better good agreement with the experimental results than those of the instability condition under isotropy theory. Beside, FLCo(plane Strain Intercept) obtained by Bethlehem FLC method and standard FLC method (modified) agree well with the experimental result.

• Journal of the Korean Magnetic Resonance Society
• /
• v.7 no.2
• /
• pp.89-97
• /
• 2003

Foot-and-mouth disease virus (FMDV) belongs to the aphthovirus genus within the picornavirus which has a single copy of a positive sense RNA. The translation initiation process of FMDV occurs by a cap-independent mechanism directed by a highly structured element (∼435 nt) termed an internal ribosome entry site (IRES). We have designed and prepared FMDV 4-2 RNA (28nt) by in vitro transcription. The 2D NMR data revealed that FMDV 4-2 IRES domain RNA has a flexible loop and bulge conformation. In further study, we need to make an isotope labeled RNA sample and conduct 3D NMR experiments to completely determine the 3D structure. This study may establish a new drug design strategy to treat foot-and mouth disease.