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The APEX Method in Image Sharpening and the Use of Low Exponent Lévy Stable Laws

Alfred S. Carasso
2003 SIAM Journal on Applied Mathematics  
The discussion includes a documented example of nonuniqueness, in which distinct point spread functions produce high-quality restorations of the same blurred image.  ...  Not all images can be enhanced with the APEX method.  ...  That class includes problems ranging from analytic continuation in the unit disc to the time-reversed Navier-Stokes equations.  ... 
doi:10.1137/s0036139901389318 fatcat:ez2e2sbmlndn7nub2nwau2z36a

Neural Operator: Learning Maps Between Function Spaces [article]

Nikola Kovachki, Zongyi Li, Burigede Liu, Kamyar Azizzadenesheli, Kaushik Bhattacharya, Andrew Stuart, Anima Anandkumar
2021 arXiv   pre-print
Numerically, the proposed models show superior performance compared to existing machine learning based methodologies on Burgers' equation, Darcy flow, and the Navier-Stokes equation, while being several  ...  We formulate the approximation of operators by composition of a class of linear integral operators and nonlinear activation functions, so that the composed operator can approximate complex nonlinear operators  ...  The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, of the Army Research Laboratory  ... 
arXiv:2108.08481v3 fatcat:fpvpnbkogvas5fl36apcia7rnq

Active Cell Divisions Generate Exotic Fourfold Orientationally Ordered Phase in Living Tissue [article]

Dillon J Cislo, Haodong Qin, Fengshuo Yang, Mark J Bowick, Sebastian J Streichan
2021 bioRxiv   pre-print
The result is a robust, active mechanism for generating global orientational order in a non-equilibrium system that sets the stage for the subsequent development of shape and form.  ...  Morphogenesis, the process through which genes generate form, establishes tissue scale order as a template for constructing the complex shapes of the body plan.  ...  In particular, we choose to model the division as a circular Eshelby inclusion of radius a and eigenstrain * αβ = (M/2) δ αβ + q (2n α nβ − δ αβ ), where δ αβ is the Kronecker delta and n is a unit vector  ... 
doi:10.1101/2021.07.28.453899 fatcat:aldpsfx4jndhjk6jv4fqtnw4jy

Interstellar turbulent velocity fields: Scaling properties, synthesis and effects on chemistry

N. Décamp, J. Le Bourlot
2002 Astronomy and Astrophysics  
Turbulence is thought to play a key role in the dynamics of interstellar clouds.  ...  We propose to use this method with the same propagator to derive quantitative information on the structure of a turbulent field.  ...  Arnéodo for discussions during a one week post-graduate course in Bordeaux, and E. Falgarone and the referee for numerous useful comments.  ... 
doi:10.1051/0004-6361:20020613 fatcat:xwkzfkmcqnaldonrsahlguviye

Lattice Boltzmann Methods for Turbulent Flows – Application to Coriolis Mass Flowmeter

Marc Haussmann
Diese lassen sich auf Grund der hervorragenden Parallelisierbarkeit der LBM mit Large-eddy Simulationen an Stelle von Reynolds-gemittelten Navier--Stokes Modellen, die im industriellen Umfeld üblich sind  ...  Acknowledgments This work was performed on the computational resource ForHLR II funded by the Ministry of Science, Research and the Arts Baden-Württemberg and DFG (\Deutsche Forschungsgemeinschaft").  ...  Acknowledgement This study was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) -422374351  ... 
doi:10.5445/ir/1000124435 fatcat:6hpr2qtkxjgfrk4xfrxvmjuzji

Inverse Problems and Experiments: a Fruitful Symbiosis

Stephane Andrieux
This paper offers a partial overview of some techniques and results emanating from inverse problems or signal processing with application to the development or enhancement of the exploitation of data obtained  ...  The first part deals with linear problems encountered in various problems of signal processing, whereas the second one addresses two specific image-based identification techniques.  ...  and enhancing performances through the use of model reduction techniques.  ... 
doi:10.12762/2016.al12-01 fatcat:ranw4rxd4fab3apur75tpzh7ly

Casting a New Light on Radiative Transfer in Solar Flare Models: Synthesis and Inversion

Christopher Osborne, Lyndsay Fletcher, Declan Diver
2021 Zenodo  
In this thesis we focus on techniques for modelling optical spectral lines in solar flare conditions, including a reassessment of previous assumptions, the radiative influence of a flare on neighbouri  ...  A two-pronged approach is therefore required to develop our understanding of this region and its reaction to flares: detailed observations, and a theoretical framework derived from complex modelling by  ...  These terms are also added to the right-hand side of the equations of ( . ), and together with the e ects of viscosity, these describe the Navier-Stokes equations. . .  ... 
doi:10.5281/zenodo.6382792 fatcat:f6zahzvooncotnxclmx6me3nki

Thermal Lattice Boltzmann Methods for the Simulation of Turbulent Flows with Conjugate Heat Transfer – Application to Refrigerated Vehicles

Maximilian Gaedtke
Wie in dieser Arbeit gezeigt wird, ermöglicht TLBM Large Eddy Simulationen (LES) solcher Probleme im industriellen und technischen Maßstab unter Verwendung eines Smagorinsky-Feinstruktur-Modells und unter  ...  For the case of weakly compressible Navier-Stokes with a truncation at order N = 2 the eddy viscosity assumption (Equation . ) is used, so that R (0) = 0, ( . ) R (1) α = 0, ( . ) R (2) αβ = −2ν turb  ...  By applying this technique to the Navier-Stokes equations -i.e. writing all variables as the sum of the time-averaged value and the fluctuating value -the Reynolds-averaged Navier-Stokes equations ( )  ... 
doi:10.5445/ir/1000126904 fatcat:dks4yecuwjaulkasfod5l4nkn4

On Kinetic Transport in Small System Collectivity and a Measurement of Separated Open Heavy Flavor Production in p+p Collisions at 200 GeV

Javier Orjuela Koop
2018 Zenodo  
This dissertation presents a comprehensive study of collective behavior in small collision systems from the point of view of the kinetic theory and also the experimental measurement of the charm and bottom  ...  ) 32 The equation of motion arising from this first order correction is called the Navier-Stokes equation.  ...  The problem, however, with relativistic Navier-Stokes theory is that the dissipative perturbation propagates instantly, violating causality.  ... 
doi:10.5281/zenodo.4539734 fatcat:xuzkujxvzrhzvg2qxewu4su3ri

OpenLB—Open source lattice Boltzmann code

M. J. Krause, A. Kummerländer, S. J. Avis, H. Kusumaatmaja, D. Dapelo, F. Klemens, M. Gaedtke, N. Hafen, A. Mink, R. Trunk, J. E. Marquardt, M.-L. Maier (+2 others)
The code is publicly available and published under GNU GPLv2, which allows for adaption and implementation of additional models.  ...  This paper summarizes the findings and gives a brief introduction to the underlying concepts as well as the design of the parallel data structure.  ...  Incompressible Navier-Stokes equations The force-free incompressible Navier-Stokes equations (NSE) read { ∂ t u + (u · ∇) u = − 1 ρ ∇p + ν∆u ∇ · u = 0 , (10) where u : X × I → R d is the macroscopic flow  ... 
doi:10.5445/ir/1000120568 fatcat:gt3wze6bbrdi5hcafyvlg35wde

Microscopic dynamics in liquid metals: The experimental point of view

Tullio Scopigno, Giancarlo Ruocco, Francesco Sette
2005 Reviews of Modern Physics  
Inelastic Neutron Scattering played a major role since the development of neutron facilities in the sixties.  ...  Finally, cutting edges issues and open problems, such as the ultimate origin of the anomalous acoustic dispersion or the relevance of transport properties of a conductive systems in ruling the ionic dynamic  ...  Henriquet), of the University of L'Aquila (O. Consorte) and of the University of Rome "La Sapienza" (I. Deen, M. Pallagrossi, C. Piacenti and A. Salvati) is also acknowledged.  ... 
doi:10.1103/revmodphys.77.881 fatcat:oplkmedezrhf3bmgbpw7nzmgey

Issue 1-December 2009-Optical Diagnostics of Flows: an Introduction

Emmanuel Rosencher
The authors thank Eric coustols from Onera in Toulouse for the coordination of wake vortex research at Onera, and frederic Moens from Onera in Meudon for the analysis of the PIv measurements.  ...  Acknowledgements We thank our colleagues of the DMPH and the DEFA for their help and for providing documentation.  ...  Only direct numerical simulation of the Navier-Stokes equations (DNS), which is model-free, could be comparable to this.  ... 

Flame surface density modelling for the large eddy simulation of turbulent premixed flames

Terence Kwai Kin Ma, Berend Van Wachem, Andrew Marquis
A relatively large range of FSDA models are tested under the same operating conditions for the first time, and the LES-FSDT equation is applied to premixed flames that involve a higher level of geometric  ...  For these reasons as well as for the higher computational expense, the effective use of FSDT requires further development, while the application of the FSDA models remains a viable alternative to the FSDT  ...  A brief overview of the three main computational modelling approaches consisting of Direct Numerical Simulations (DNS), Reynolds Averaged Navier Stokes (RANS) and Large Eddy Simulation (LES) are also described  ... 
doi:10.25560/14645 fatcat:yy3jp62v2vfsvolf6bbe5qnpcy

Progress towards a source of cold, slow molecules for tests of fundamental physics

James Bumby, Mike Tarbutt, Edward Hinds, Engineering And Physical Sciences Research Council
By integrating over all bleached molecules, we measured the number of YbF molecules with a given velocity.  ...  We optically bleached population from a target hyperfine level of certain Doppler classes within the molecular beam.  ...  You kept me focused and motivated when things were at their most difficult, and would always make time for my questions and dilemmas at the drop of a hat. Thank you all.  ... 
doi:10.25560/44971 fatcat:gk4nth6ajvhtpljptyezvh4qt4


Branislav Čadjenović, Radmila Marković, Aleksandra Milosavljević, Radmila Marković, Bernd Friedrich, Jasmina Stevanović, Bore, Jegdić
For better understanding the electrochemical behavior of recycled anodes, the corrosive behavior of anodes was studied in a three arrangement cell.  ...  The possibility of nickel separation and production from this solution in a form of salts using chemical method or pure metal form of electrochemical deposition is feasible according to concentration increasing  ...  ADSORPTION OF ARSENIC COMPONENTS ON LAYERED DOUBLE HYDROXIDES AND MIXED OXIDES FOR WATER PURIFICATION Acknowledgment This research was supported by the Economic Competitiveness Operational Programme "Development  ... 
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