Publications related to Parallel filtering in global gyrokinetic simulations

Simulating background shear flow in local gyrokinetic simulations

Stephan Brunner, Justin Richard Ball, Ben McMillan

Local gyrokinetic simulations solve the gyrokinetic equations with homogeneous background gradients, typically using a doubly periodic domain in the (x, y) plane (i.e. perpendicular to the field line). Spatial Fourier representations are almost universal i ...

2019

Stable Manifold for the Critical Non-Linear Wave Equation: A Fourier Theory Approach

Gérôme Graf

I will try to explain, without going into too much detail, how one can consider a non-linear wave equation as a dynamical system and what it brings to the study of its solutions. We begin by considering our model case, the non-linear Klein-Gordon equation ...

EPFL2019

A non-stationary stochastic ensemble generator for radar rainfall fields based on the short-space Fourier transform

Nikola Besic, Urs Martin Germann, Daniele Nerini

In this paper we present a non-stationary stochastic generator for radar rainfall fields based on the short-space Fourier transform (SSFT). The statistical properties of rainfall fields often exhibit significant spatial heterogeneity due to variability in ...

Copernicus GmbH2017

An Adaptive Sublinear-Time Block Sparse Fourier Transform

Volkan Cevher, Mikhail Kapralov, Jonathan Mark Scarlett, Amir Zandieh

The problem of approximately computing the

k

dominant Fourier coefficients of a vector

X

quickly, and using few samples in time domain, is known as the Sparse Fourier Transform (sparse FFT) problem. A long line of work on the sparse FFT has resulted in ...

2017

On Short Sums Of Trace Functions

Philippe Michel, Chandra Sekhar Raju

We consider sums of oscillating functions on intervals in cyclic groups of size close to the square root of the size of the group. We first prove non-trivial estimates for intervals of length slightly larger than this square root (bridging the "Polya-Vinog ...

Annales Inst Fourier2017

A sparse reconstruction framework for Fourier-based plane wave imaging

Jean-Philippe Thiran, Yves Wiaux, Rafael Eduardo Carrillo Rangel, Adrien Georges Jean Besson, Olivier Bernard

Ultrafast imaging based on plane-wave (PW) insonification is an active area of research due to its capability of reaching high frame rates. Among PW imaging methods, Fourier-based approaches have demonstrated to be competitive compared to traditional delay ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Effective a posteriori Co-Phasing of Interferometric Fringe Data

Ferréol Arnaud Marie Soulez

We have recently shown that a posteriori co-phasing of multi-spectral interferograms was possible.(1) In this contribution, we extend our approach so that it can be applied to actual data as provided by AMBER(2) or MATISSE instruments. The main advantage o ...

SPIE2016

Flexibeam: Analytic Spatial Filtering By Beamforming

Paul Hurley, Matthieu Martin Jean-André Simeoni

We propose a new, general, method for spatial filtering by beam-forming. The desired filter, specified analytically on an n-dimensional sphere, is extended to n+1-dimensional Euclidean space. A continuous beamforming function is then obtained by the n+1-di ...

Ieee2016

Divergence-Free Wavelet Frames

Michaël Unser, Emrah Bostan, John Paul Ward

We propose an efficient construction of wavelet frames in any number of dimensions that are divergence-free. Our approach is based on applying the Leray projector, which is scale-invariant, to a standard wavelet frame. We prove that the projected wavelets ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Superresolution Reconstruction for Magnetic Resonance Spectroscopic Imaging Exploiting Low-Rank Spatio-Spectral Structure

Magnetic resonance spectroscopic imaging (MRSI) is a rapidly developing medical imaging modality, capable of conferring both spatial and spectral information content, and has become a powerful clinical tool. The ability to non-invasively observe spatial ma ...

EPFL2015

Parallel filtering in global gyrokinetic simulations

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Simulating background shear flow in local gyrokinetic simulations

Stable Manifold for the Critical Non-Linear Wave Equation: A Fourier Theory Approach

A non-stationary stochastic ensemble generator for radar rainfall fields based on the short-space Fourier transform

An Adaptive Sublinear-Time Block Sparse Fourier Transform

On Short Sums Of Trace Functions

A sparse reconstruction framework for Fourier-based plane wave imaging

Effective a posteriori Co-Phasing of Interferometric Fringe Data

Flexibeam: Analytic Spatial Filtering By Beamforming

Divergence-Free Wavelet Frames

Superresolution Reconstruction for Magnetic Resonance Spectroscopic Imaging Exploiting Low-Rank Spatio-Spectral Structure

Simulating background shear flow in local gyrokinetic simulations

A non-stationary stochastic ensemble generator for radar rainfall fields based on the short-space Fourier transform

On Short Sums Of Trace Functions

A sparse reconstruction framework for Fourier-based plane wave imaging

Superresolution Reconstruction for Magnetic Resonance Spectroscopic Imaging Exploiting Low-Rank Spatio-Spectral Structure

Divergence-Free Wavelet Frames

Flexibeam: Analytic Spatial Filtering By Beamforming

Stable Manifold for the Critical Non-Linear Wave Equation: A Fourier Theory Approach

An Adaptive Sublinear-Time Block Sparse Fourier Transform

Effective a posteriori Co-Phasing of Interferometric Fringe Data