Results 21 to 30 of about 18,020 (238)

Regularity and blow up for active scalars [PDF]

, 2010
We review some recent results for a class of fluid mechanics equations called active scalars, with fractional dissipation. Our main examples are the surface quasi-geostrophic equation, the Burgers equation, and the Cordoba-Cordoba-Fontelos model.
Kiselev, Alexander
core   +2 more sources

Low-Light Enhancement Model in Natural Scenes Based on Generative Adversarial Network [PDF]

Jisuanji gongcheng
In the most current low-light image enhancement models, both illumination enhancement and original image feature preservation are difficult to achieve and hard to adapt to a variety of different low-light conditions in natural scenes.To address these ...
Ruijun YANG, Jinjing QIN, Yan CHENG
doaj   +1 more source

No interactions for a collection of Weyl gravitons intermediated by a scalar field [PDF]

, 2006
The cross-couplings among several Weyl gravitons (described in the free limit by a sum of linearized Weyl actions) in the presence of a scalar field are studied with the help of the deformation theory based on local BRST cohomology.
A. C. LUNGU, C. BIZDADEA, E. M. CIOROIANU, Henneaux M.   +3 more
core   +2 more sources

Discrete mechanics and optimal control: An analysis [PDF]

, 2009
The optimal control of a mechanical system is of crucial importance in many application areas. Typical examples are the determination of a time-minimal path in vehicle dynamics, a minimal energy trajectory in space mission design, or optimal motion ...
Junge, Oliver, Marsden, Jerrold E., Ober-Blöbaum, Sina   +2 more
core   +3 more sources

A Novel Euler's Elastica based Segmentation Approach for Noisy Images via using the Progressive Hedging Algorithm [PDF]

, 2019
Euler's Elastica based unsupervised segmentation models have strong capability of completing the missing boundaries for existing objects in a clean image, but they are not working well for noisy images.
Li, Ling, Liu, Wanquan, Sun, Jie, Tan, Lu, Zhang, Min   +4 more
core   +2 more sources

Approximation by Symmetrized and Perturbed Hyperbolic Tangent Activated Convolution-Type Operators

Mathematics
In this article, for the first time, the univariate symmetrized and perturbed hyperbolic tangent activated convolution-type operators of three kinds are introduced.
George A. Anastassiou
doaj   +1 more source

Area preservation in computational fluid dynamics

, 1999
Incompressible two-dimensional flows such as the advection (Liouville) equation and the Euler equations have a large family of conservation laws related to conservation of area.
Arakawa, Lax, Marsden, Robert I. McLachlan, Scovel, Zeitlin   +5 more
core   +2 more sources

Direct model fitting to combine dithered ACS images [PDF]

, 2013
The information lost in images of undersampled CCD cameras can be recovered with the technique of `dithering'. A number of subexposures is taken with sub-pixel shifts in order to record structures on scales smaller than a pixel.
Mahmoudian, Haniyeh, Wucknitz, Olaf
core   +2 more sources

Global smoothness preservation by bivariate interpolation operators

Analysis in Theory and Applications, 2003
The authors extend some interesting results proved earlier by themselves in the univariate case to the bivariate one. They also remark that the results can easily be extended for \(m\) \((> 2)\) variables, too. More precisely they prove that the bivariate interpolation polynomials of Hermite-Fejér based on the Chebyshev nodes of the first kind, those ...
Gal, S. G., Szabados, J.
openaire   +2 more sources

Multivariate Approximation Using Symmetrized and Perturbed Hyperbolic Tangent-Activated Multidimensional Convolution-Type Operators

Axioms
In this article, we introduce, for the first time, multivariate symmetrized and perturbed hyperbolic tangent-activated convolution-type operators in three forms.
George A. Anastassiou
doaj   +1 more source