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This paper is concerned with inverse scattering of plane waves by a locally perturbed infinite plane (which is called a locally rough surface) with the modulus of the total-field data (also called the phaseless near-field data) at a fixed…

Numerical Analysis · Mathematics 2018-08-28 Xiaoxu Xu , Bo Zhang , Haiwen Zhang

Multipole expansion of an incident radiation field - that is, representation of the fields as sums of vector spherical wavefunctions - is essential for theoretical light scattering methods such as the T-matrix method and generalised…

Optics · Physics 2007-05-23 T. A. Nieminen , H. Rubinsztein-Dunlop , N. R. Heckenberg

Fractional diffusion equations (FDEs) are a mathematical tool used for describing some special diffusion phenomena arising in many different applications like porous media and computational finance. In this paper, we focus on a…

Numerical Analysis · Mathematics 2017-10-11 Hamid Moghaderi , Mehdi Dehghan , Marco Donatelli , Mariarosa Mazza

Using the traditional surface integral methods, the computation of scattering from a dielectric object requires two equivalent current densities on the boundary of the dielectric. In this paper, we present an approach that requires only a…

Computational Engineering, Finance, and Science · Computer Science 2017-08-02 Utkarsh R. Patel , Piero Triverio , Sean V. Hum

We present a progressive image decomposition method based on a novel non-linear filter named Sub-window Variance filter. Our method is specifically designed for image detail enhancement purpose; this application requires extraction of image…

Computer Vision and Pattern Recognition · Computer Science 2021-07-23 Kin-Ming Wong

In this paper, we develop a high order numerical method for the numerical solutions of scattering problems with slightly perturbed periodic surfaces in two dimensional spaces. Based on the regularity property introduced in Part I, the…

Numerical Analysis · Mathematics 2018-09-27 Ruming Zhang

The multipole expansion method (MEM) is a spatial discretization technique that is widely used in applications that feature scattering of waves from circular cylinders. Moreover, it also serves as a key component in several other numerical…

Numerical Analysis · Mathematics 2021-06-04 Brian Fitzpatrick , Enzo De Sena , Toon van Waterschoot

The instantaneous two-dimensional wall shear rate is assessed through an inverse problem using mass transfer data from a three-segment electrodiffusion probe. The method is validated numerically in complex flow conditions involving (i) high…

Fluid Dynamics · Physics 2018-12-19 Marc-Étienne Lamarche-Gagnon , Jérôme Vétel

We present a PDE-based approach for the multidimensional extrapolation of smooth scalar quantities across interfaces with kinks and regions of high curvature. Unlike the commonly used method of [2] in which normal derivatives are…

Numerical Analysis · Mathematics 2023-09-26 Daniil Bochkov , Frederic Gibou

The use of orthonormal wavelet basis functions for solving singular integral scattering equations is investigated. It is shown that these basis functions lead to sparse matrix equations which can be solved by iterative techniques. The…

Nuclear Theory · Physics 2009-11-10 B. M. Kessler , G. L. Payne , W. N. Polyzou

This paper presents high-order integral equation methods for evaluation of electromagnetic wave scattering by dielectric bumps and dielectric cavities on perfectly conducting or dielectric half-planes. In detail, the algorithms introduced…

Computational Physics · Physics 2015-06-19 Carlos Pérez-Arancibia , Oscar P. Bruno

We study the problem of space and time efficient evaluation of a nonparametric estimator that approximates an unknown density. In the regime where consistent estimation is possible, we use a piecewise multivariate polynomial interpolation…

Statistics Theory · Mathematics 2020-11-11 Paxton Turner , Jingbo Liu , Philippe Rigollet

An integral equation-based numerical method for scattering from multi-dielectric cylinders is presented. Electromagnetic fields are represented via layer potentials in terms of surface densities with physical interpretations. The existence…

Computational Physics · Physics 2019-05-01 Johan Helsing , Anders Karlsson

Scattering of time-harmonic plane wave by two parallel semi-infinite rows, but with staggered edges, is considered on square lattice. The condition imposed on the semi-infinite rows is a discrete analogue of Neumann boundary condition. A…

Mathematical Physics · Physics 2019-09-04 Gaurav Maurya , Basant Lal Sharma

As the use of spectral/$hp$ element methods, and high-order finite element methods in general, continues to spread, community efforts to create efficient, optimized algorithms associated with fundamental high-order operations have grown.…

Numerical Analysis · Mathematics 2022-01-11 Edward Laughton , Vidhi Zala , Akil Narayan , Robert M. Kirby , David Moxey

We present a new methodology, based on the WKB approximation and Fast Fourier Transforms, for the evaluation of wave propagation through inhomogeneous media. This method can accurately resolve fields containing caustics, while still…

Computational Physics · Physics 2024-03-05 Oscar P. Bruno , Martin D. Maas

Kernel density estimation and kernel regression are powerful but computationally expensive techniques: a direct evaluation of kernel density estimates at $M$ evaluation points given $N$ input sample points requires a quadratic…

Computation · Statistics 2020-02-18 Nicolas Langrené , Xavier Warin

In this paper, we study the inverse electromagnetic medium scattering problem of estimating the support and shape of medium scatterers from scattered electric or magnetic near-field data. We shall develop a novel direct sampling method…

Numerical Analysis · Mathematics 2015-06-12 Kazufumi Ito , Bangti Jin , Jun Zou

This paper is concerned with the inverse scattering problem by an unbounded rough surface. A direct imaging method is proposed to reconstruct the rough surface from the scattered near-field Cauchy data generating by point sources and…

Numerical Analysis · Mathematics 2018-05-01 Xiaoli Liu , Bo Zhang , Haiwen Zhang

We consider wave propagation problems over 2-dimensional domains with piecewise-linear boundaries, possibly including scatterers. We assume that the wave speed is constant, and that the initial conditions and forcing terms are radially…

Numerical Analysis · Mathematics 2025-03-14 Davide Pradovera , Monica Nonino , Ilaria Perugia
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