2,674 research outputs found
Constrained low-tubal-rank tensor recovery for hyperspectral images mixed noise removal by bilateral random projections
In this paper, we propose a novel low-tubal-rank tensor recovery model, which
directly constrains the tubal rank prior for effectively removing the mixed
Gaussian and sparse noise in hyperspectral images. The constraints of
tubal-rank and sparsity can govern the solution of the denoised tensor in the
recovery procedure. To solve the constrained low-tubal-rank model, we develop
an iterative algorithm based on bilateral random projections to efficiently
solve the proposed model. The advantage of random projections is that the
approximation of the low-tubal-rank tensor can be obtained quite accurately in
an inexpensive manner. Experimental examples for hyperspectral image denoising
are presented to demonstrate the effectiveness and efficiency of the proposed
method.Comment: Accepted by IGARSS 201
2-tert-Butyl 4-methyl 3,5-dimethyl-1H-pyrrole-2,4-dicarboxylÂate
In the title molÂecule, C13H19NO4, except for two C atoms of the tert-butyl group, the non-H atoms are almost coplanar (r.m.s. deviation = 0.2542 Å). In the crystal, molÂecules are linked into centrosymmetric dimers by two interÂmolecular N—H⋯O hydrogen bonds, forming an R
2
2(10) ring motif
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MAP3Kinase-dependent SnRK2-kinase activation is required for abscisic acid signal transduction and rapid osmotic stress response.
Abiotic stresses, including drought and salinity, trigger a complex osmotic-stress and abscisic acid (ABA) signal transduction network. The core ABA signalling components are snf1-related protein kinase2s (SnRK2s), which are activated by ABA-triggered inhibition of type-2C protein-phosphatases (PP2Cs). SnRK2 kinases are also activated by a rapid, largely unknown, ABA-independent osmotic-stress signalling pathway. Here, through a combination of a redundancy-circumventing genetic screen and biochemical analyses, we have identified functionally-redundant MAPKK-kinases (M3Ks) that are necessary for activation of SnRK2 kinases. These M3Ks phosphorylate a specific SnRK2/OST1 site, which is indispensable for ABA-induced reactivation of PP2C-dephosphorylated SnRK2 kinases. ABA-triggered SnRK2 activation, transcription factor phosphorylation and SLAC1 activation require these M3Ks in vitro and in plants. M3K triple knock-out plants show reduced ABA sensitivity and strongly impaired rapid osmotic-stress-induced SnRK2 activation. These findings demonstrate that this M3K clade is required for ABA- and osmotic-stress-activation of SnRK2 kinases, enabling robust ABA and osmotic stress signal transduction
(E,E)-3,3′-Dimethyl-1,1′-diphenyl-4,4′-{[3-azaÂpentane-1,5-diylbis(azaÂnediÂyl)]bisÂ(phenylÂmethylÂidyne)}di-1H-pyrazol-5(4H)-one
The asymmetric unit of the title compound, C38H37N7O2, contains one half-molÂecule, situated on a twofold rotational axis, in which one amino group is involved in intraÂmolecular N—H⋯O hydrogen bond and the two phenyl rings are twisted from the plane of pyrazolone ring by 26.69 (10) and 79.64 (8)°. The crystal packing exhibits no classical interÂmolecular contacts
SVCNet: Scribble-based Video Colorization Network with Temporal Aggregation
In this paper, we propose a scribble-based video colorization network with
temporal aggregation called SVCNet. It can colorize monochrome videos based on
different user-given color scribbles. It addresses three common issues in the
scribble-based video colorization area: colorization vividness, temporal
consistency, and color bleeding. To improve the colorization quality and
strengthen the temporal consistency, we adopt two sequential sub-networks in
SVCNet for precise colorization and temporal smoothing, respectively. The first
stage includes a pyramid feature encoder to incorporate color scribbles with a
grayscale frame, and a semantic feature encoder to extract semantics. The
second stage finetunes the output from the first stage by aggregating the
information of neighboring colorized frames (as short-range connections) and
the first colorized frame (as a long-range connection). To alleviate the color
bleeding artifacts, we learn video colorization and segmentation
simultaneously. Furthermore, we set the majority of operations on a fixed small
image resolution and use a Super-resolution Module at the tail of SVCNet to
recover original sizes. It allows the SVCNet to fit different image resolutions
at the inference. Finally, we evaluate the proposed SVCNet on DAVIS and Videvo
benchmarks. The experimental results demonstrate that SVCNet produces both
higher-quality and more temporally consistent videos than other well-known
video colorization approaches. The codes and models can be found at
https://github.com/zhaoyuzhi/SVCNet.Comment: accepted by IEEE Transactions on Image Processing (TIP
VCGAN: Video Colorization with Hybrid Generative Adversarial Network
We propose a hybrid recurrent Video Colorization with Hybrid Generative
Adversarial Network (VCGAN), an improved approach to video colorization using
end-to-end learning. The VCGAN addresses two prevalent issues in the video
colorization domain: Temporal consistency and unification of colorization
network and refinement network into a single architecture. To enhance
colorization quality and spatiotemporal consistency, the mainstream of
generator in VCGAN is assisted by two additional networks, i.e., global feature
extractor and placeholder feature extractor, respectively. The global feature
extractor encodes the global semantics of grayscale input to enhance
colorization quality, whereas the placeholder feature extractor acts as a
feedback connection to encode the semantics of the previous colorized frame in
order to maintain spatiotemporal consistency. If changing the input for
placeholder feature extractor as grayscale input, the hybrid VCGAN also has the
potential to perform image colorization. To improve the consistency of far
frames, we propose a dense long-term loss that smooths the temporal disparity
of every two remote frames. Trained with colorization and temporal losses
jointly, VCGAN strikes a good balance between color vividness and video
continuity. Experimental results demonstrate that VCGAN produces higher-quality
and temporally more consistent colorful videos than existing approaches.Comment: Submitted Major Revision Manuscript of IEEE Transactions on
Multimedia (TMM
Ethyl 5-{[(E)-2-(isonicotinoyl)hydrazinylÂidene]methyl}-3,4-dimethyl-1H-pyrrole-2-carboxylÂate dihydrate
In the title compound, C16H18N4O3·2H2O, the dihedral angle between the pyrrole and pyridine rings in the hydrazone molÂecule is 7.12 (3)°. In the crystal structure, interÂmolecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds link the hydrazone and water molÂecules into double layers parallel to (101). The crystal packing exhibits weak π–π interÂactions between the pyrrole and pyridine rings of neighbouring hydrazone molÂecules [centroid–centroid distance = 3.777 (3) Å]. The crystal studied was a non-merohedral twin, the refined ratio of twin domains being 0.73 (3):0.27 (3)
Quantum chemistry calculation aided design of chiral ionic liquid-based extraction system for amlodipine separation
Amlodipine is a widely used medication in treating hypertension, which is also
known as a chiral compound. So far efforts have been made to obtain optically pure
(S)-amlodipine because (R)-amlodipine has poor efficacy and is related to undesirable side
effects. However, the available separation methods for amlodipine are still unsatisfactory.
Recently, chiral separation has become a promising application of chiral ionic liquids (CILs),
because the structural designability enables them adjustable separation efficiency for specific
tasks. In this work, a high-efficient CIL-based liquid-liquid extraction system was developed
for racemic amlodipine separation with the assistance of quantum chemistry calculations.
Enantioselectivity up to 1.35 achieved by the novel system at 298.15 K is significantly higher
than other available extraction systems. Moreover, the recycling of CIL can be easily realized
by backward extraction of amlodipine, which is important for the industrial application of
CILs
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