58,127 research outputs found
Non-blind Image Restoration Based on Convolutional Neural Network
Blind image restoration processors based on convolutional neural network
(CNN) are intensively researched because of their high performance. However,
they are too sensitive to the perturbation of the degradation model. They
easily fail to restore the image whose degradation model is slightly different
from the trained degradation model. In this paper, we propose a non-blind
CNN-based image restoration processor, aiming to be robust against a
perturbation of the degradation model compared to the blind restoration
processor. Experimental comparisons demonstrate that the proposed non-blind
CNN-based image restoration processor can robustly restore images compared to
existing blind CNN-based image restoration processors.Comment: Accepted by IEEE 7th Global Conference on Consumer Electronics, 201
Jet-cloud interations and the brightening of the narrow line region in Seyfert galaxies
We study the kinematical and brightness evolution of emission line clouds in
the narrow line region (NLR) of Seyfert galaxies during the passage of a jet.
We derive a critical density above which a cloud remains radiative after
compression by the jet cocoon. The critical density depends mainly on the
cocoon pressure. Super-critical clouds increase in emission line brightness,
while sub-critical clouds generally are highly overheated reducing their
luminosity below that of the inter-cloud medium. Due to the pressure
stratification in the bow-shock of the jet, a cylindrical structure of nested
shells develops around the jet. The most compact and brightest compressed
clouds surround the cloud-free channel of the radio jet. To support our
analytical model we present a numerical simulation of a supersonic jet
propagating into a clumpy NLR. The position-velocity diagram of the simulated
H_alpha emission shows total line widths of the order of 500 km/s with
large-scale variations in the radial velocities of the clouds due to the
stratified pressure in the bow-shock region of the jet. Most of the luminosity
is concentrated in a few dense clouds surrounding the jet. These morphological
and kinematic signatures are all found in the well observed NLR of NGC1068 and
other Seyfert galaxies.Comment: 11 pages, 3 figures, accepted for publication in The Astrophysical
Journal Letter
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