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One of the main computational drawbacks in the application of 3-D iterative inversion techniques is the requirement of solving the field quantities for the updated contrast in every iteration. In this paper, the 3-D electromagnetic inverse…

Signal Processing · Electrical Eng. & Systems 2019-06-27 Shilong Sun , Bert Jan Kooij , Alexander G. Yarovoy

We introduce and analyze a fast iterative method based on sequential Bregman projections for nonlinear inverse problems in Banach spaces. The key idea, in contrast to the standard Landweber method, is to use multiple search directions per…

Numerical Analysis · Mathematics 2018-08-01 Anne Wald

We develop theoretical results that establish a connection across various regression methods such as the non-negative least squares, bounded variable least squares, simplex constrained least squares, and lasso. In particular, we show in…

Computation · Statistics 2024-10-29 James Yang , Trevor Hastie

A new non-linear optimization approach is proposed for the sparse reconstruction of log-conductivities in current density impedance imaging. This framework comprises of minimizing an objective functional involving a least squares fit of the…

Optimization and Control · Mathematics 2020-06-30 Madhu Gupta , Rohit Kumar Mishra , Souvik Roy

This work has been submitted to the IEEE for possible publication. Copyright may be transferred without notice, after which this version may no longer be accessible. Computational imaging, especially non-line-of-sight (NLOS) imaging, the…

Computer Vision and Pattern Recognition · Computer Science 2026-04-01 Lianfang Wang , Kuilin Qin , Xueying Liu , Huibin Chang , Yong Wang , Yuping Duan

We consider the problem of finding a sparse solution for an underdetermined linear system of equations when the known parameters on both sides of the system are subject to perturbation. This problem is particularly relevant to…

Systems and Control · Computer Science 2016-06-16 Reza Arablouei

Many imaging science tasks can be modeled as a discrete linear inverse problem. Solving linear inverse problems is often challenging, with ill-conditioned operators and potentially non-unique solutions. Embedding prior knowledge, such as…

Numerical Analysis · Mathematics 2023-12-07 Elizabeth Newman , Jack Michael Solomon , Matthias Chung

This paper presents a new algorithmic framework for computing sparse solutions to large-scale linear discrete ill-posed problems. The approach is motivated by recent perspectives on iteratively reweighted norm schemes, viewed through the…

Numerical Analysis · Mathematics 2025-02-05 Lucas Onisk , Malena Sabaté Landman

Microwave imaging is commonly based on the solution of linearized inverse scattering problems by matched filtering algorithms, i.e., by applying the adjoint of the forward scattering operator to the observation data. A more rigorous…

Image and Video Processing · Electrical Eng. & Systems 2024-12-23 Matthias M. Saurer , Han Na , Marius Brinkmann , Thomas F. Eibert

The nonlinear Schr\"odinger equation (NLSE) is a fundamental model for wave dynamics in nonlinear media ranging from optical fibers to Bose-Einstein condensates. Accurately estimating its parameters, which are often strongly correlated,…

Quantum Physics · Physics 2025-09-24 Louis Rossignol , Tangui Aladjidi , Myrann Baker-Rasooli , Quentin Glorieux

We consider parameter identification problems in parametrized partial differential equations (PDE). This leads to nonlinear ill-posed inverse problems. One way to solve them are iterative regularization methods, which typically require…

Numerical Analysis · Mathematics 2018-05-07 Dominik Garmatter , Bernard Haasdonk , Bastian Harrach

Inverse imaging problems that are ill-posed can be encountered across multiple domains of science and technology, ranging from medical diagnosis to astronomical studies. To reconstruct images from incomplete and distorted data, it is…

Image and Video Processing · Electrical Eng. & Systems 2023-11-30 Cesar F. Caiafa , Ramiro M. Irastorza

Image reconstruction of EIT mathematically is a typical nonlinear and severely ill-posed inverse problem. Appropriate priors or penalties are required to enable the reconstruction. The commonly used L2-norm can enforce the stability to…

Numerical Analysis · Mathematics 2018-03-13 Jing Wang , Bo Han , Wei Wang

In image denoising (IDN) processing, the low-rank property is usually considered as an important image prior. As a convex relaxation approximation of low rank, nuclear norm based algorithms and their variants have attracted significant…

Image and Video Processing · Electrical Eng. & Systems 2020-04-03 Yanwei Zhao , Ping Yang , Qiu Guan , Jianwei Zheng , Wanliang Wang

We introduce a novel optimization algorithm for image recovery under learned sparse and low-rank constraints, which we parameterize as weighted extensions of the $\ell_p^p$-vector and $\mathcal S_p^p$ Schatten-matrix quasi-norms for…

Computer Vision and Pattern Recognition · Computer Science 2023-04-21 Stamatios Lefkimmiatis , Iaroslav Koshelev

We investigate the ill-posed inverse problem of recovering unknown spatially dependent parameters in nonlinear evolution PDEs. We propose a bi-level Landweber scheme, where the upper-level parameter reconstruction embeds a lower-level state…

Numerical Analysis · Mathematics 2024-03-07 Tram Thi Ngoc Nguyen

The idea of unfolding iterative algorithms as deep neural networks has been widely applied in solving sparse coding problems, providing both solid theoretical analysis in convergence rate and superior empirical performance. However, for…

Machine Learning · Computer Science 2020-10-27 Yuhai Song , Zhong Cao , Kailun Wu , Ziang Yan , Changshui Zhang

Non-linear least squares solvers are used across a broad range of offline and real-time model fitting problems. Most improvements of the basic Gauss-Newton algorithm tackle convergence guarantees or leverage the sparsity of the underlying…

Computer Vision and Pattern Recognition · Computer Science 2020-10-22 Huu Le , Christopher Zach , Edward Rosten , Oliver J. Woodford

We study the problem of recovering the underlining sparse signals from clean or noisy phaseless measurements. Due to the sparse prior of signals, we adopt an L0regularized variational model to ensure only a small number of nonzero elements…

Optimization and Control · Mathematics 2016-12-09 Yuping Duan , Chunlin Wu , Zhi-Feng Pang , Huibin Chang

We consider the inverse scattering problem for sparse scatterers. An image reconstruction algorithm is proposed that is based on a nonlinear generalization of iterative hard thresholding. The convergence and error of the method was analyzed…

Numerical Analysis · Mathematics 2019-03-27 Anna C. Gilbert , Howard W. Levinson , John C. Schotland
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