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This paper presents a novel Bayesian approach for hyperspectral image unmixing. The observed pixels are modeled by a linear combination of material signatures weighted by their corresponding abundances. A spike-and-slab abundance prior is…

Applications · Statistics 2022-05-04 Zeng Li , Yoann Altmann , Jie Chen , Stephen Mclaughlin , Susanto Rahardja

This work proposes a method to identify and isolate the physical mechanisms that are responsible for linear energy amplification in fluid flows. This is achieved by applying a sparsity-promoting methodology to the resolvent form of the…

Fluid Dynamics · Physics 2025-04-17 Scott T. M. Dawson , Jaime Prado Zayas , Barbara Lopez-Doriga

The numerically stable evaluation of scattering matrix elements near the infrared limit of gauge theories is of great importance for the success of collider physics experiments. We present a novel algorithm that utilizes double precision…

High Energy Physics - Phenomenology · Physics 2024-10-04 Enrico Bothmann , John M. Campbell , Stefan Höche , Max Knobbe

This work deals with a regularization method enforcing solution sparsity of linear ill-posed problems by appropriate discretization in the image space. Namely, we formulate the so called least error method in an $\ell^1$ setting and perform…

Numerical Analysis · Mathematics 2016-08-03 Kristian Bredies , Barbara Kaltenbacher , Elena Resmerita

We apply adaptive sensing techniques to the problem of locating sparse metallic scatterers using high-resolution, frequency modulated continuous wave W-band RADAR. Using a single detector, a frequency stepped source, and a lateral…

Consider the scattering of a time-harmonic plane wave by heterogeneous media consisting of linear or nonlinear point scatterers and extended obstacles. A generalized Foldy-Lax formulation is developed to take fully into account of the…

Numerical Analysis · Mathematics 2017-06-22 Jun Lai , Ming Li , Peijun Li , Wei Li

We study detection and imaging of small reflectors in heavy clutter, using an array of transducers that emits and receives sound waves. Heavy clutter means that multiple scattering of the waves in the heterogeneous host medium is strong and…

Computational Physics · Physics 2018-06-27 Liliana Borcea , George Papanicolaou , Chrysoula Tsogka

Wave propagation and acoustic scattering problems require vast computational resources to be solved accurately at high frequencies. Asymptotic methods can make this cost potentially frequency independent by explicitly extracting the…

Numerical Analysis · Mathematics 2018-01-16 Daan Huybrechs , Peter Opsomer

We present a quantitative study of coherent array imaging of remote sources in randomly perturbed waveguides with bounded cross-section. We study how long range cumulative scattering by perturbations of the boundary and the medium impedes…

Numerical Analysis · Mathematics 2013-06-10 Liliana Borcea , Josselin Garnier , Chrysoula Tsogka

We propose a methodology that exploits large and diverse data sets to accurately estimate the ambient medium's Green's functions in strongly scattering media. Given these estimates, obtained with and without the use of neural networks,…

Machine Learning · Computer Science 2024-12-05 Alexander Christie , Matan Leibovich , Miguel Moscoso , Alexei Novikov , George Papanicolaou , Chrysoula Tsogka

Thomson scattering of laser light is one of the most fundamental diagnostics of plasma density, temperature and magnetic fields. It relies on the assumption that the properties in the probed volume are homogeneous and constant during the…

Plasma Physics · Physics 2016-04-29 P. M. Kozlowski , B. J. B. Crowley , D. O. Gericke , S. P. Regan , G. Gregori

Many optical measurement techniques, such as light scattering from wavelength-scale particles or detecting motion from a surface with an optical lever, encode information in a complex radiation pattern. Extracting all available information…

Quantum Physics · Physics 2025-12-22 Youssef Tawfik , Shan Hao , Thomas P. Purdy

Accurate subsurface scattering solutions require the integration of optical material properties along many complicated light paths. We present a method that learns a simple geometric approximation of random paths in a homogeneous volume of…

Graphics · Computer Science 2020-11-09 Ludwig Leonard , Kevin Hoehlein , Ruediger Westermann

This paper treats the problem of minimizing a general continuously differentiable function subject to sparsity constraints. We present and analyze several different optimality criteria which are based on the notions of stationarity and…

Information Theory · Computer Science 2012-03-22 Amir Beck , Yonina C. Eldar

The study of the scattering of electromagnetic waves by a linear isotropic medium with planar symmetry can be reduced to that of their TE and TM modes. For situations where the medium consists of parallel homogeneous slabs, one may use the…

Quantum Physics · Physics 2025-03-25 Farhang Loran , Ali Mostafazadeh

In this paper, we address the problem of detecting multiple Noise-Like Jammers (NLJs) through a radar system equipped with an array of sensors. To this end, we develop an elegant and systematic framework wherein two architectures are…

Signal Processing · Electrical Eng. & Systems 2020-04-28 Linjie Yan , Pia Addabbo , Yuxuan Zhang , Chengpeng Hao , Jun Liu , Jian Li , Danilo Orlando

Optical interferometers provide multiple wavelength measurements. In order to fully exploit the spectral and spatial resolution of these instruments, new algorithms for image reconstruction have to be developed. Early attempts to deal with…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Éric Thiébaut , Ferréol Soulez , Loïc Denis

We address combinatorial problems that can be formulated as minimization of a partially separable function of discrete variables (energy minimization in graphical models, weighted constraint satisfaction, pseudo-Boolean optimization, 0-1…

Computer Vision and Pattern Recognition · Computer Science 2015-05-05 Alexander Shekhovtsov

In statistical machine learning, kernel methods allow to consider infinite dimensional feature spaces with a computational cost that only depends on the number of observations. This is usually done by solving an optimization problem…

Optimization and Control · Mathematics 2019-01-17 Guillaume Garrigos , Lorenzo Rosasco , Silvia Villa

We present a novel algorithm that allows us to gain detailed insight into the effects of sparsity in linear and nonlinear optimization, which is of great importance in many scientific areas such as image and signal processing, medical…

Optimization and Control · Mathematics 2021-09-23 Katharina Bieker , Bennet Gebken , Sebastian Peitz