TY  - JOUR
A1  - Bernardi, Rafael L.
A1  - Berdja, Amokrane
A1  - Dani Guzman, Christian
A1  - Torres-Torriti, Miguel
A1  - Roth, Martin M.
T1  - Restoration of images with a spatially varying PSF of the T80-S telescope optical model using neural networks
JF  - Monthly notices of the Royal Astronomical Society
N2  - Most image restoration methods in astronomy rely upon probabilistic tools that infer the best solution for a deconvolution problem. They achieve good performances when the point spread function (PSF) is spatially invariant in the image plane. 

However, this condition is not always satisfied in real optical systems. We propose a new method for the restoration of images affected by static and anisotropic aberrations using Deep Neural Networks that can be directly applied to sky images. 
The network is trained using simulated sky images corresponding to the T80-S Telescope optical model, a 80-cm survey imager at Cerro Tololo (Chile), which are synthesized using a Zernike polynomial representation of the optical system. 

Once trained, the network can be used directly on sky images, outputting a corrected version of the image that has a constant and known PSF across its field of view. The method is to be tested on the T80-S Telescope. 
We present the method and results on synthetic data.
KW  - methods: statistical
KW  - techniques: image processing
Y1  - 2021
U6  - https://doi.org/10.1093/mnras/stab3400
SN  - 0035-8711
SN  - 1365-2966
VL  - 510
IS  - 3
SP  - 4284
EP  - 4294
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Zhong, Qi
A1  - Mi, Lei
A1  - Metwalli, Ezzeldin
A1  - Biessmann, Lorenz
A1  - Philipp, Martine
A1  - Miasnikova, Anna
A1  - Laschewsky, Andre
A1  - Papadakis, Christine M.
A1  - Cubitt, Robert
A1  - Schwartzkopf, Matthias
A1  - Roth, Stephan V.
A1  - Wang, Jiping
A1  - Müller-Buschbaum, Peter
T1  - Effect of chain architecture on the swelling and thermal response of star-shaped thermo-responsive (poly(methoxy diethylene glycol acrylate)-block-polystyrene)(3) block copolymer films
JF  - Soft matter
N2  - The effect of chain architecture on the swelling and thermal response of thin films obtained from an amphiphilic three-arm star-shaped thermo-responsive block copolymer poly(methoxy diethylene glycol acrylate)-block-polystyrene ((PMDEGA-b-PS)(3)) is investigated by in situ neutron reflectivity (NR) measurements. The PMDEGA and PS blocks are micro-phase separated with randomly distributed PS nanodomains. The (PMDEGA-b-PS)(3) films show a transition temperature (TT) at 33 degrees C in white light interferometry. The swelling capability of the (PMDEGA-b-PS)(3) films in a D2O vapor atmosphere is better than that of films from linear PS-b-PMDEGA-b-PS triblock copolymers, which can be attributed to the hydrophilic end groups and limited size of the PS blocks in (PMDEGA-b-PS)(3). However, the swelling kinetics of the as-prepared (PMDEGA-b-PS)(3) films and the response of the swollen film to a temperature change above the TT are significantly slower than that in the PS-b-PMDEGA-b-PS films, which may be related to the conformation restriction by the star-shape. Unlike in the PS-b-PMDEGA-b-PS films, the amount of residual D2O in the collapsed (PMDEGA-b-PS)(3) films depends on the final temperature. It decreases from (9.7 +/- 0.3)% to (7.0 +/- 0.3)% or (6.0 +/- 0.3)% when the final temperatures are set to 35 degrees C, 45 degrees C and 50 degrees C, respectively. This temperature-dependent reduction of embedded D2O originates from the hindrance of chain conformation from the star-shaped chain architecture.
Y1  - 2018
U6  - https://doi.org/10.1039/c8sm00965a
SN  - 1744-683X
SN  - 1744-6848
VL  - 14
IS  - 31
SP  - 6582
EP  - 6594
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  -