English
Related papers

Related papers: Sampling the flow of a bandlimited function

200 papers

In this paper we consider the problem of recovering the conformal factor in a conformal class of Riemannian metrics from the boundary measurement of one wave field. More precisely, using boundary control operators, we derive an explicit…

Analysis of PDEs · Mathematics 2015-03-30 Sebastian Acosta

In this paper, we investigate frames for $L_2[-\pi,\pi]^d$ consisting of exponential functions in connection to oversampling and nonuniform sampling of bandlimited functions. We derive a multidimensional nonuniform oversampling formula for…

Numerical Analysis · Mathematics 2010-09-13 Benjamin Aaron Bailey

Perturbed plane Couette flow containing a thin spanwise-oriented ribbon undergoes a subcritical bifurcation at Re = 230 to a steady 3D state containing streamwise vortices. This bifurcation is followed by several others giving rise to a…

Fluid Dynamics · Physics 2009-11-10 Laurette S. Tuckerman , Dwight Barkley

Plasmoid-mediated reconnection plays a fundamental role in different solar atmospheric phenomena. Numerical reproduction of this process is therefore essential for developing robust solar models. Our goal is to assess plasmoid-mediated…

Solar and Stellar Astrophysics · Physics 2024-03-13 Øystein Håvard Færder , Daniel Nóbrega-Siverio , Mats Carlsson

Four different applications of spectral proper orthogonal decomposition (SPOD): low-rank reconstruction, denoising, frequency-time analysis, and prewhitening are demonstrated on large-eddy simulation data of a turbulent jet. SPOD-based…

Fluid Dynamics · Physics 2021-09-22 Akhil Nekkanti , Oliver T. Schmidt

Ground-to-space astronomical super-resolution requires recovering space-quality images from ground-based observations that are simultaneously limited by pixel sampling resolution and atmospheric seeing, which imposes a stochastic, spatially…

Computer Vision and Pattern Recognition · Computer Science 2026-05-08 Shuhong Liu , Xining Ge , Ziteng Cui , Liuzhuozheng Li , Gengjia Chang , Jun Liu , Ziying Gu , Dong Li , Xuangeng Chu , Lin Gu , Tatsuya Harada

We investigate the statistical recovery of missing physics and turbulent phenomena in fluid flows using generative machine learning. Here we develop a two-stage super-resolution method using spectral filtering to restore the high-wavenumber…

Phase retrieval refers to the problem of recovering some signal (which is often modelled as an element of a Hilbert space) from phaseless measurements. It has been shown that in the deterministic setting phase retrieval from frame…

Numerical Analysis · Mathematics 2021-11-11 Rima Alaifari , Matthias Wellershoff

In this work, we study an inverse problem of recovering a space-time dependent diffusion coefficient in the subdiffusion model from the distributed observation, where the mathematical model involves a Djrbashian-Caputo fractional derivative…

Numerical Analysis · Mathematics 2022-09-23 Bangti Jin , Zhi Zhou

The Wiener Filter (WF) technique enables the reconstruction of density and velocity fields from observed radial peculiar velocities. This paper aims at identifying the optimal design of peculiar velocity surveys within the WF framework. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-19 Jenny G. Sorce , Yehuda Hoffman , Stefan Gottlöber

We experimentally demonstrate that highly structured distributions of work emerge during even the simple task of erasing a single bit. These are signatures of a refined suite of time-reversal symmetries in distinct functional classes of…

Some metrological means, such as Shack-Hartmann, deflectometry sensors or fringe projection profilometry, measure the shape of an optical surface indirectly from slope measurements. Zonal shape reconstruction, a method to reconstruct shape…

In this paper, we present a novel reconstruction method for diffuse optical spectroscopic imaging with a commonly used tissue model of optical absorption and scattering. It is based on linearization and group sparsity, which allows…

Numerical Analysis · Mathematics 2019-03-06 Habib Ammari , Bangti Jin , Wenlong Zhang

We add a time-dependent potential to the inhomogeneous wave equation and consider the task of reconstructing this potential from measurements of the wave field. This dynamic inverse problem becomes more involved compared to static…

Numerical Analysis · Mathematics 2017-08-24 Thies Gerken , Armin Lechleiter

This paper considers the reconstruction problem in Acousto-Electrical Tomography, i.e., the problem of estimating a spatially varying conductivity in a bounded domain from measurements of the internal power densities resulting from…

Numerical Analysis · Mathematics 2020-01-13 Simon Hubmer , Kim Knudsen , Changyou Li , Ekaterina Sherina

4D Flow MRI is the state of the art technique for measuring blood flow, and it provides valuable information for inverse problems in the cardiovascular system. However, 4D Flow MRI has a very long acquisition time, straining healthcare…

Numerical Analysis · Mathematics 2025-12-09 Miriam Löcke , Pim van Ooij , Cristóbal Bertoglio

We consider a wireless sensor network, sampling a bandlimited field, described by a limited number of harmonics. Sensor nodes are irregularly deployed over the area of interest or subject to random motion; in addition sensors measurements…

Other Computer Science · Computer Science 2009-11-13 A. Nordio , C. -F. Chiasserini , E. Viterbo

We propose a novel method to reconstruct volumetric flows from sparse views via a global transport formulation. Instead of obtaining the space-time function of the observations, we reconstruct its motion based on a single initial state. In…

Computer Vision and Pattern Recognition · Computer Science 2025-03-20 Aleksandra Franz , Barbara Solenthaler , Nils Thuerey

We investigate the problem of reconstructing a 2D piecewise smooth function from its bandlimited Fourier measurements. This is a well known and well studied problem with many real world implications, in particular in medical imaging. While…

Numerical Analysis · Mathematics 2025-03-05 Michael Levinov , Yosef Yomdin , Dmitry Batenkov

In ultrasound nondestructive testing, a widespread approach is to take synthetic aperture measurements from the surface of a specimen to detect and locate defects within it. Based on these measurements, imaging is usually performed using…

Signal Processing · Electrical Eng. & Systems 2020-12-09 Jan Kirchhof , Sebastian Semper , Christoph W. Wagner , Eduardo Pérez , Florian Römer , Giovanni Del Galdo