• 제목/요약/키워드: Emission Report

검색결과 458건 처리시간 0.031초

Search for broadband extended gravitational-wave emission bursts in LIGO S6 in 350-2000 Hz by GPU acceleration

  • van Putten, Maurice H.P.M.
    • 천문학회보
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    • 제42권1호
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    • pp.37.3-37.3
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    • 2017
  • We present a novel GPU accelerated search algorithm for broadband extended gravitational-wave emission (BEGE) with better than real-time analyis of H1-L1 LIGO S6 data. It performs matched filtering with over 8 million one-second duration chirps. Parseval's Theorem is used to predict the standard deviation ${\sigma}$ of filter output, taking advantage of near-Gaussian LIGO (H1,L1)-data in the high frequency range of 350-2000 Hz. A multiple of ${\sigma}$ serves as a threshold to filter output back to the central processing unit. This algorithm attains 80% efficiency, normalized to the Fast Fourier Transform (FFT). We apply it to a blind, all-sky search for BEGE in LIGO data, such as may be produced by long gamma-ray bursts and superluminous supernovae. We report on mysterious features, that are excluded by exact simultaneous occurrance. Our results are consistent with no events within a radius of about 20 Mpc.

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Observing the central engine of GRB170817A

  • van Putten, Maurice H.P.M.
    • 천문학회보
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    • 제43권1호
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    • pp.39.2-39.2
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    • 2018
  • GW170817/GRB170817A establishes a double neutron star merger as the progenitor of a short gamma-ray burst, starting 1.7 s post-coalescence. GRB170817A represents prompt or continuous emission from a newly formed hyper-massive neutron star or black hole. We report on a deep search for broadband extended gravitational-wave emission in spectrograms up to 700 Hz of LIGO O2 data covering this event produced by butterfly filtering comprising a bank of templates of 0.5 s. A detailed discussion is given of signal-to-noise ratios in image analysis of spectrograms and confidence levels of candidate features. This new pipeline is realized by heterogeneous computing with modern graphics processor units (GPUs). (Based on van Putten, M.H.PM., 2017, PTEP, 093F01.)

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New red light-emitting copolymer based on polyfluorene

  • Cho, Nam-Sung;Hwang, Do-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.721-723
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    • 2002
  • We report a new red light emitting fluorene-based copolymer, poly{9,9-bis(2'-ethylhexyl)fluorene-2,7-diyl-co-2, 5-bis(2-thienyl-1-cyanovinyl}-1-(2'-ethylhexyloxy)-4methoxybenzene-5",5'''-diyl} (PFTCVB). The synthesized copolymers showed the absorption maxima at about 380 nm and the absorption between 425 and 600 nm increased as the fraction of the thiophene-containing monomer (BTCVB) increased. In PL, the emission maxima of the copolymers were red-shifted as the fraction of BTCVB increased, despite the similar absorption characteristics were shown in the UV-visible spectra. The copolymer containing 15 mol% of BTCVB showed a maximum PL and EL emission at 620 and 630 nm.

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Color tunable electroluminescence with polymer blends composed of PVK and copolymer containing SiPh-PPV and MEH-PPV unit

  • Oh, Gwang-Chae;Yun, Je-Jung;Park, Su-Mi;Son, Sung-Hee;Han, Eun-Mi;Jin, Sung-Ho;Gu, Hal-Bon;Choi, Hyun-Chual
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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    • pp.736-739
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    • 2002
  • We report on white light emission from a light emitting diode(LED) prepared by blending a red emitting copolymer, m-SiPh PPV-co-MEH PPV, and a blue emitting polyvinylcarbazole (PVK). White light emission was realized when the weight ratio of the m-SiPh PPV-co-MEH PPV : PVK equals to 1 : 30, in which the commission Internationale de L'Eclairage coordinates were x=0.3266 and y=0.3438.

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Fabrication of Beta-phase Poly(9,9-dioctylfluorene) Nanowire Arrays for Polymer Light-Emitting Diode Using Direct Printing Method

  • 백장미;이기석;성명모
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.560-560
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    • 2012
  • We report a one-step fabrication method of Poly(9,9-dioctylfluorene) (PFO) nanowire array with pronounced ${\beta}$-Phase. We use liquid-bridge-mediated nanotransfer molding (LB-nTM) which is a new direct nano-patterning method based on the direct transfer of various materials from a mold to a substrate via liquid layer. The formation of the ${\beta}$-phase morphology in the resulting PFO nanowire array was evidenced by the presence of an absorption peak at 435nm. With the collection polarizer oriented parallel to the wire long axis, the PL emission was most intense and an emission dichroic ratio, DRE, of 3.7 was determined. The nanowire array have been investigated by scanning electron microscopy (SEM). Also, we simply fabricated structure of device of ITO/PFO nanowire arrays/Al and the electroluminescence spectra were recorded at various applied voltage.

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사이클로트론 구성부품별 고장통계분석 (Analysis on Failure Statistics of Cyclotron Component)

  • 조준호;정재은;정홍문;원도연
    • 대한디지털의료영상학회논문지
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    • 제16권1호
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    • pp.61-67
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    • 2014
  • The demand of cyclotron for PET (positron emission tomography) has rapidly grown as the more use of PET or PET-CT equipment requires the increased amount of radioactive isotopes for clinical positron emission. While research on failure statistics of medical equipment used in medical centers has continued to be done, the analysis and study on failure statistics of cyclotron have rarely been conducted. However, the growing demand shows the urgency of systematical management guideline and countermeasures for device failure to minimize any supply delay of radiopharmaceuticals occurred by such failure and complains from waiting patients for PET-CT diagnosis. Therefore, this study aims to analyze the failure report from Minitrace equipped in cyclotron which is owned by the department of nuclear medicine at Yeungnam University Medical Center and draws on the data to build effective management system for cyclotron.

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Detection of a Large Amount of Diffuse Extraplanar Dust in NGC 891

  • 선광일
    • 천문학회보
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    • 제36권2호
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    • pp.71.1-71.1
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    • 2011
  • Significant discrepancies have been found between the dust masses of edge-on spiral galaxies derived from various tracers (optical/near-infrared, far-infrared/sub-millimeter observations, and the variation of dust attenuation with viewing angle). Here we report the first detection of a vertically extended far-ultraviolet (FUV) and near-UV (NUV) emission in an edge-on spiral galaxy NGC 891. The vertically extended emission is interpreted as the dust-scattered light due to a extraplanar dust layer in NGC 891 that contains about the same mass as the standard thin dust disk. This new dust component completely encloses the stellar disk and bulge, and solves the puzzle of dust mass.

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철도 궤도시스템의 LCCO2에 관한 소고 (Some Thoughts on LCCO2 of the Railway Track System)

  • 전민녀;이우철;최상현;임남형
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2009년도 춘계학술대회 논문집
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    • pp.548-551
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    • 2009
  • The report of the intergovernment panel on climate change(IPCC) concluded that the global warning due to Green-house Gas(GHGs) will be accelerated in the 21th century. The railroad construction sector consumes a great deal of natural resources and energy in construction. maintenance, and demolition stage. In order to establish and perform reducing plan of GHGs of railway track system for effective corresponding the Climate Change Agreement, the evaluation method of the lifecycle CO2 emission if needed. In this research, it was investigates that the research trend for the LCCO2 and the method to estimate the lifecycle carbon dioxide emission amount of the railway track system as quantitative.

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C IV Emission-line Detection of the Supernova Remnant RCW 114

  • Kim, Il-Joong;Min, Kyoung-Wook;Seon, Kwang-Il;Han, Won-Young;Edelstein, Jerry
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.33.3-33.3
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    • 2009
  • We report the detection of the C IV $\lambda\lambda1548$, 1551 emission line in the region of the RCW 114 nebula using the FIMS/SPEAR data. The observed C IV line intensity indicates that RCW 114 is much closer to us than HD 156385, a Wolf-Rayet star that was thought to be associated with RCW 114 in some of the previous studies. We also found the existence of a small H I bubble centered on HD 156385, with a different LSR velocity range from that of the large H I bubble which was identified previously as related to RCW 114. These findings imply that the RCW 114 nebula is an old supernova remnant which is not associated with the Wolf-Rayet star, HD 156385. Additionally, the global morphology of the C IV and $H{\alpha}$ emissions shows that RCW 114 has evolved in a non-uniform interstellar medium.

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Visible Wavelength Photonic Insulator for Enhancing LED Light Emission

  • Ryoo, Kwangki;Lee, Jeong Bong
    • Journal of information and communication convergence engineering
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    • 제13권1호
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    • pp.50-55
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    • 2015
  • We report design and simulation of a two-dimensional (2D) silicon-based nanophotonic crystal as an optical insulator to enhance the light emission efficiency of light-emitting diodes (LEDs). The device was designed in a manner that a triangular array silicon photonic crystal light insulator has a square trench in the middle where LED can be placed. By varying the normalized radius in the range of 0.3-0.5 using plane wave expansion method (PWEM), we found that the normalized radius of 0.45 creates a large band gap for transverse electric (TE) polarization. Subsequently a series of light propagation simulation were carried out using 2D and three-dimensional (3D) finite-difference time-domain (FDTD). The designed silicon-based light insulator device shows optical characteristics of a region in which light propagation was forbidden in the horizontal plane for TE light with most of the visible light spectrum in the wavelength range of 450 nm to 600 nm.