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The purpose of this note is to present a proof of the existence of Gabor frames in general linear position in all finite dimensions. The tools developed in this note are also helpful towards an explicit construction of such a frame, which…

Rings and Algebras · Mathematics 2020-05-04 Romanos-Diogenes Malikiosis

We solve acoustic scattering problems by means of the isogeometric boundary integral equation method. In order to avoid spurious modes, we apply the combined field integral equations for either sound-hard scatterers or sound-soft…

Numerical Analysis · Mathematics 2023-06-21 Jürgen Dölz , Helmut Harbrecht , Michael Multerer

In this paper, given a linear system of equations A x = b, we are finding locations in the plane to place objects such that sending waves from the source points and gathering them at the receiving points solves that linear system of…

Numerical Analysis · Mathematics 2021-02-16 Kthim Imeri

We consider the two-dimensional high-frequency plane wave scattering problem in the exterior of a finite collection of disjoint, compact, smooth, strictly convex obstacles with Neumann boundary conditions. Using integral equation…

Numerical Analysis · Mathematics 2022-08-15 Yassine Boubendir , Fatih Ecevit

Nonstationary Gabor frames were recently introduced in adaptive signal analysis. They represent a natural generalization of classical Gabor frames by allowing for adaptivity of windows and lattice in either time or frequency. In this paper…

Functional Analysis · Mathematics 2012-07-19 Monika Dörfler , Ewa Matusiak

So far there has not been paid attention to frames that are balanced, i.e. those frames which sum is zero. In this paper we consider balanced frames, and in particular balanced unit norm tight frames, in finite dimensional Hilbert spaces.…

Functional Analysis · Mathematics 2020-09-28 Sigrid B. Heineken , Patricia M. Morillas , Pablo Tarazaga

In this paper, we apply star-Digital Gabor Transform in analysis Compressed Sensing and speech denoising. Based on assumptions on the ambient dimension, we produce a window vector that generates a spark deficient Gabor frame with many…

Numerical Analysis · Mathematics 2021-10-19 Vasiliki Kouni , Holger Rauhut

The frame set of a function $g\in L^2(\mathbb{R})$ is the subset of all parameters $(a, b)\in \mathbb{R}^2_+$ for which the time-frequency shifts of $g$ along $a\mathbb{Z}\times b\mathbb{Z}$ form a Gabor frame for $L^2(\mathbb{R}).$ In this…

Functional Analysis · Mathematics 2018-06-05 A. Ganiou D. Atindehou , Yebeni B. Kouagou , Kasso A. Okoudjou

We consider an inner problem for whispering gallery high-frequency asymptotic mode's scattering by a boundary inflection. The related boundary-value problem for a Schr\"{o}dinger equation on a half-line with a potential linear in both space…

Analysis of PDEs · Mathematics 2021-03-09 V. P. Smyshlyaev , I. V. Kamotski

Based on a unique waveform with strong exponential localization property, an exact mathematical method for solving problems in signal analysis in time-frequency domain is presented. An analogue of the Gabor frame exposes the non-commutative…

Mathematical Physics · Physics 2012-06-12 Aramazd H. Muzhikyan , Gagik T. Avanesyan

In this paper, exact solutions to the problem of acoustic scattering by elastic spherical symmetric scatterers are developed. The scatterer may consist of an arbitrary number of fluid and solid layers, and scattering with single Neumann…

Mathematical Physics · Physics 2022-04-21 Jon Vegard Venås , Trond Jenserud

The model problem of scattering of a sound wave by an infinite plane structure formed by a semi-infinite acoustically hard screen and a semi-infinite sandwich panel perforated from one side and covered by a membrane from the other is…

Mathematical Physics · Physics 2023-04-11 Y. A. Antipov

In this paper we examine iterative methods for solving the forward ($A{\bf x}={\bf b}$) and adjoint ($A^{T}{\bf y}={\bf g}$) systems of linear equations used to approximate the scattering amplitude, defined by ${\bf g}^{T}{\bf x}={\bf…

Numerical Analysis · Mathematics 2015-03-24 Amber S. Robertson , James V. Lambers

In this paper a mathematical model is given for the scattering of an incident wave from a surface covered with microscopic small Helmholtz resonators, which are cavities with small openings. More precisely, the surface is built upon a…

Numerical Analysis · Mathematics 2020-02-03 Habib Ammari , Kthim Imeri

We discuss the concepts of pseudo-dual frames and approximately dual frames, and illuminate their relationship to classical frames. Approximately dual frames are easier to construct than the classical dual frames, and might be tailored to…

Classical Analysis and ODEs · Mathematics 2008-11-24 Ole Christensen , Richard S. Laugesen

Consider the scattering of an acoustic plane wave by a bounded elastic obstacle which is immersed in an open space filled with a homogeneous medium. This paper concerns the mathematical analysis of the coupled two- and three-dimensional…

Analysis of PDEs · Mathematics 2018-12-03 Peijun Li , Lei Zhang

A method for detecting and approximating fault lines or surfaces, respectively, or decision curves in two and three dimensions with guaranteed accuracy is presented. Reformulated as a classification problem, our method starts from a set of…

Numerical Analysis · Mathematics 2023-02-17 Matthias Grajewski , Andreas Kleefeld

We construct frames adapted to a given cover of the time-frequency or time-scale plane. The main feature is that we allow for quite general and possibly irregular covers. The frame members are obtained by maximizing their concentration in…

Functional Analysis · Mathematics 2015-04-27 Monika Dörfler , José Luis Romero

We analyze actual methods that generate smooth frame fields both in 2D and in 3D. We formalize the 2D problem by representing frames as functions (as it was done in 3D), and show that the derived optimization problem is the one that…

Graphics · Computer Science 2015-07-14 Nicolas Ray , Dmitry Sokolov

Gabor functions have wide-spread applications in image processing and computer vision. In this paper, we prove that 2D Gabor functions are translation-invariant positive-definite kernels and propose a novel formulation for the problem of…

Computer Vision and Pattern Recognition · Computer Science 2017-12-11 Kamaledin Ghiasi-Shirazi