English
Related papers

Related papers: Array imaging of localized objects in homogeneous …

200 papers

As light travels through a disordered medium such as biological tissues, it undergoes multiple scattering events. This phenomenon is detrimental to in-depth optical microscopy, as it causes a drastic degradation of contrast, resolution and…

Direct imaging methods recover the presence, position, and shape of the unknown obstacles in time-harmonic inverse scattering without a priori knowledge of either the physical properties or the number of disconnected components of the…

Analysis of PDEs · Mathematics 2023-11-29 General Ozochiawaeze

We develop a new computational tool and framework for characterizing the scattering of photons by energy-nonconserving Hamiltonians into unidirectional (chiral) waveguides, for example, with coherent pulsed excitation. The temporal…

Quantum Physics · Physics 2018-05-30 Kevin A. Fischer , Rahul Trivedi , Vinay Ramasesh , Irfan Siddiqi , Jelena Vučković

The problem studied in this paper is ultrasound image reconstruction from frequency-domain measurements of the scattered field from an object with contrast in attenuation and sound speed. The case where the object has uniform but unknown…

Computer Vision and Pattern Recognition · Computer Science 2015-03-19 H. Emre Guven , Eric L. Miller , Robin O. Cleveland

Image reconstruction under multiple light scattering is crucial in a number of applications such as diffraction tomography. The reconstruction problem is often formulated as a nonconvex optimization, where a nonlinear measurement model is…

Computer Vision and Pattern Recognition · Computer Science 2018-07-04 Yu Sun , Zhihao Xia , Ulugbek S. Kamilov

We propose a speed-up method for the in-focus plane detection in digital holographic microscopy that can be applied to a broad class of autofocusing algorithms that involve repetitive propagation of an object wave to various axial locations…

Quantitative Methods · Quantitative Biology 2023-05-19 Julianna Winnik , Damian Suski , Piotr Zdańkowski , Luiza Stanaszek , Vicente Micó , Maciej Trusiak

Homogenization of a thin micro-structure yields effective jump conditions that incorporate the geometrical features of the scatterers. These jump conditions apply across a thin but nonzero thickness interface whose interior is disregarded.…

Computational Physics · Physics 2017-03-08 Bruno Lombard , Agnes Maurel , Jean-Jacques Marigo

We present a novel algorithm for high resolution coherent imaging of sound sources in random scattering media using time resolved measurements of the acoustic pressure at an array of receivers. The sound waves travel a long distance between…

Numerical Analysis · Mathematics 2017-12-15 Liliana Borcea , Ilker Kocyigit

Modeling the propagation of light through disordered media is central to understanding and controlling wave transport in diverse optical and mesoscopic applications. Here, we present a random matrix simulation framework for modeling the…

Optics · Physics 2026-02-24 Niall Byrnes , Sulagna Dutta , Matthew R. Foreman

The presence of a scattering medium in the imaging path between an object and an observer is known to severely limit the visual acuity of the imaging system. We present an approach to circumvent the deleterious effects of scattering, by…

We consider the distribution of the transmission coefficients, i.e. the singular values of the modal transmission matrix, for 2D random media with periodic boundary conditions composed of a large number of point-like non-absorbing…

Disordered Systems and Neural Networks · Physics 2015-04-15 Curtis Jin , Raj Rao Nadakuditi , Eric Michielssen

A simple stochastic formulation of the multiple scattering representation solution of the classical linear incoherent trapping problem is presented for a broad audience. A clear connection with the alternative Holstein's solution ansatz is…

Physics Education · Physics 2007-05-23 E. J. Nunes-Pereira , A. R. Alves-Pereira , J. M. G. Martinho , M. N. Berberan-Santos

We present a theoretical and experimental study of light transport in disordered media with strongly heterogeneous distribution of scatterers formed via non-scattering regions. Step correlations induced by quenched disorder are found to…

Disordered Systems and Neural Networks · Physics 2014-03-05 Tomas Svensson , Kevin Vynck , Erik Adolfsson , Andrea Farina , Antonio Pifferi , Diederik S. Wiersma

Sparse signal restoration is usually formulated as the minimization of a quadratic cost function $\|y-Ax\|_2^2$, where A is a dictionary and x is an unknown sparse vector. It is well-known that imposing an $\ell_0$ constraint leads to an…

Numerical Analysis · Computer Science 2015-05-29 Charles Soussen , Jérôme Idier , Junbo Duan , David Brie

In this paper, we discuss application of iterative Stochastic Optimization routines to the problem of sparse signal recovery from noisy observation. Using Stochastic Mirror Descent algorithm as a building block, we develop a multistage…

Machine Learning · Statistics 2022-03-31 Anatoli Juditsky , Andrei Kulunchakov , Hlib Tsyntseus

This paper investigates a fully unsupervised statistical method for edge preserving image restoration and compression using a spatial decomposition scheme. Smoothed maximum likelihood is used for local estimation of edge pixels from mixture…

Methodology · Statistics 2016-11-26 Kinjal Basu , Debapriya Sengupta

We consider a discrete optimization formulation for learning sparse classifiers, where the outcome depends upon a linear combination of a small subset of features. Recent work has shown that mixed integer programming (MIP) can be used to…

Machine Learning · Statistics 2021-06-08 Antoine Dedieu , Hussein Hazimeh , Rahul Mazumder

In this paper, we study robust stability of sparse LTI systems using the stability radius (SR) as a robustness measure. We consider real perturbations with an arbitrary and pre-specified sparsity pattern of the system matrix and measure…

Systems and Control · Computer Science 2018-10-26 Vaibhav Katewa , Fabio Pasqualetti

We present a physically intuitive matrix approach for wave imaging and characterization in scattering media. The experimental proof-of-concept is performed with ultrasonic waves, but this approach can be applied to any field of wave physics…

Applied Physics · Physics 2020-07-01 William Lambert , Laura A. Cobus , Mathieu Couade , Mathias Fink , Alexandre Aubry

Finding a sparse representation of a possibly noisy signal can be modeled as a variational minimization with l_q-sparsity constraints for q less than one. Especially for real-time, on-line, or iterative applications, in which problems of…

Numerical Analysis · Mathematics 2017-09-04 Martin Ehler