• 천문학회보
• /
• 제41권2호
• /
• pp.29.5-30
• /
• 2016

(1) The correlation between the mass of supermassive black holes (SMBHs) and the properties of their host galaxies suggests that SMBHs and host galaxies are closely linked in their formation and evolution. While the exact origin of their relationship is still under debate, theoretical models often invoke feedback from active galactic nuclei as a crucial mechanism for establishing the BH-host correlation. In the first part of my talk, I will present our efforts to find observational sign of the AGN feedback in young luminous AGNs. (2) While intermediate-mass black hole (IMBH) is thought be cosmologically important class to understand the link between stellar mass black holes and SMBHs, it is extremely rare in the present-day Universe. In the second part of this talk, I will report a Gemini/GMOS-N IFU study of an ultraluminous X-ray source in NGC 5252, which is a possible candidate of an off-nuclear non-stellar black hole.

• 천문학회보
• /
• 제37권1호
• /
• pp.51.2-51.2
• /
• 2012

Red Active Galactic Nuclei (AGNs) are suspected to intermediate stage between ULIRG and AGN phase. As well as, red AGNs are suspected to have more than 50% of whole AGN population. For understanding the characteristics of red AGN, Black Hole (BH) mass is a key property and can not be estimated by existed method such as reverberation mapping and single epoch method using 5100A continuum and Balmer lines. Thus we still don't know their characteristics and properties in clearly. To estimate properties of red AGNs without the effect of dust extinction, we obtained Near InfraRed (NIR) spectra of 31 reverberation mapped AGNs and 49 Palomar-Green(PG) Quasi-Stellar Objects (QSOs) by using the infrared camera (IRC) of AKARI space telescope with unique wavelength range 2.5-5.0 ${\mu}m$. Upon this spectra, we measured the FWHM and luminosity of Brackett ${\alpha}$ and ${\beta}$ lines for deriving new BH mass estimators of AGNs.

• 천문학회보
• /
• 제42권1호
• /
• pp.27.4-27.4
• /
• 2017

(1) The correlation between the mass of supermassive black holes (SMBHs) and the properties of their host galaxies suggests that SMBHs and host galaxies are closely linked in their formation and evolution. While the exact origin of their relationship is still under debate, theoretical models often invoke feedback from active galactic nuclei as a crucial mechanism for establishing the BH-host correlation. In the first part of my talk, I will present possible observational biases in the BH-host relation, and methods to overcome these biases. I will also report our efforts to find observational sign of the AGN feedback in high-z young luminous AGNs. (2) While intermediate-mass black hole (IMBH) is thought be cosmologically important class to understand the link between stellar mass black holes and SMBHs, it is extremely rare in the present-day Universe. In the second part of this talk, I will report a Gemini/GMOS-N IFU study of an ultraluminous X-ray source in NGC 5252, which is a possible candidate of an off-nuclear non-stellar black hole.

• 화약ㆍ발파
• /
• 제15권3호
• /
• pp.20-32
• /
• 1997

The pressure-time profile of the explosion gases can be controlled fot the use of cartridge explosives with two techniques Known as Decoupling and Spacing the charges. Decoupling consists in leaving and empty space between the explosive column and wall of the blast hole. Four different decoupling index, 1.4, 1.8, 2.34, 3.0 are selected in this field study. The level of ground vibrations with each decoupling index are measured and the empirical particle vibrations with each decoupling index are measured and the empirical particle velocity equation from these data was obtained. The condition of new cracks at blast hole are also examined. As the decoupling index in increased, the level of the blast vibration is decreased,. But the cracks in rock masses are efficiently formed to remove the broken rock. The vibration constant associated with a given site $K=1564.5(D.I)^{-1.3233}$ in terms of D.I(decopling index).

• 대한전기학회논문지
• /
• 제37권3호
• /
• pp.163-170
• /
• 1988

In order to investigate the mechanism of pyroelectricity on polyvinylidene fluoride film, the observations were carried out on the characteristics of infrared spectra, thermally stimulated current and pyroelectric current. As the results obtained from the study, it was concluded that the origin for thermally stimulated current exhibited above room temperature can be attributed to hole injected from anode during poling process. Futhermore it is clarified also that the origin of pyroelectricity observed on the specimen concerned is to spontaneous polarization of CF dipole attached to molecular chain segment, however, the fraction of spontaneous polarization is largely influenced by the amount of hole injected from anode.

• 천문학논총
• /
• 제4권1호
• /
• pp.1-15
• /
• 1989

A jet plasmoid model for 3C.449 has been constructed by introducing a plasma.ejecting black hole orbiting around the center of its parent cD galaxy. We examined the characteristics of the jet trajectory by varying the values of (1) orbiting radius and velocity of the black hole, (2) plasma ejection velocity, (3) size, mass and space velocity of the parent galaxy, (4) size of the galactic core and (5) the density of the intergalactic medium. In our model calculation the effect of the gravity by the parent galaxy and the ram pressure by the intergalactic medium have been taken in account. It is found that our dynamical model accounts reasonably well for the observed structure of 3C449. Our proposed model suggests that the buoyancy force near the galactic center plays an important role in the formation of the curved structure of the radio jet.

• 천문학논총
• /
• 제30권2호
• /
• pp.475-476
• /
• 2015

We analyze the host galaxy of the tidal disruption object, Swift J1644+57, based on long-term optical to NIR data obtained with CQUEAN and UKIRT WFCAM observations. We decompose the bulge component using high resolution HST WFC3 images. We conclude that the host galaxy is bulge dominant. We investigate optical to NIR light curves and estimate the multi-band fluxes of the host galaxy. We fit spectral energy distribution (SED) models in order to determine the stellar mass. Finally, we estimate the mass of the black hole in the center of the host galaxy based on several scale relations.

• 한국정보통신학회:학술대회논문집
• /
• 한국해양정보통신학회 2010년도 춘계학술대회
• /
• pp.728-729
• /
• 2010

Opportunistic spectrum access (OSA) allows unlicensed users to share licensed spectrum in space and time with no or little interference to primary users, with bring new research challenges in MAC design. We propose a cognitive MAC protocol using statistical channel utilization information and selecting appropriate spectrum hole for multi-channel data transmission. The protocol based on the CSMA/CA, exploits statistics of spectrum usage for decision making on channel access.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
• /
• pp.508-509
• /
• 2005

In case of ITO/MEH-PPV/Al structure, the quantity of charge carriers flowing through the organic material was few and the density of them is fixed. The electric field inside of the device almost didn't change with the position. On the other hands, in case of Au/MEH-PPV/Au structure, the hole density increased rapidly nearby the anode but decreased nearby the cathode. The space charge phenomenon followed sufficient hole injection resulted in the change of the electric field with the position inside of the device. We verified that the result of the current-voltage simulation corresponded with experimental result.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2008년도 춘계학술대회 논문집
• /
• pp.469-472
• /
• 2008

This research suggest one-body type scrapped styrofoam crusher with sprayed air (or water), which at present separately composed of dust eliminator, air supplier and crusher. Air (or water) that supplied from compressor injected to rotating twin roller through axis hole, and sprayed out of fine hole on the surface. The crusher that manufactured with sprayed air (or water) can make high-quality primary styrofoam removed pollution and dust. In case of mixed sprayed air and water, clean degree of crushed styrofoam was higher than single sprayed air. This could be contributed to reduce environmental pollution, cost and space in standpoint of recycling scrapped styrofoam.