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This paper develops a convex approach for sparse one-dimensional deconvolution that improves upon L1-norm regularization, the standard convex approach. We propose a sparsity-inducing non-separable non-convex bivariate penalty function for…

Optimization and Control · Mathematics 2016-04-19 Ivan W. Selesnick , Iker Bayram

We study the Tikhonov regularization for ill-posed non-linear operator equations in Hilbert scales. Our focus is on the interplay between the smoothness-promoting properties of the penalty and the smoothness inherent in the solution. The…

Numerical Analysis · Mathematics 2018-01-17 Bernd Hofmann , Peter Mathé

How can we compute the pseudoinverse of a sparse feature matrix efficiently and accurately for solving optimization problems? A pseudoinverse is a generalization of a matrix inverse, which has been extensively utilized as a fundamental…

Machine Learning · Computer Science 2020-11-10 Jinhong Jung , Lee Sael

For approximately solving linear ill-posed problems in Hilbert spaces, we investigate the regularization properties of the aggregation method and the RatCG method. These recent algorithms use previously calculated solutions of Tikhonov…

Numerical Analysis · Mathematics 2026-01-16 Stefan Kindermann

The least-square regression problems or inverse problems have been widely studied in many fields such as compressive sensing, signal processing, and image processing. To solve this kind of ill-posed problems, a regularization term (i.e.,…

Numerical Analysis · Mathematics 2014-05-12 Gang Liu , Ting-Zhu Huang , Xiao-Guang Lv , Jun Liu

Total least squares (TLS) is an effective method for solving linear equations with the situations, when noise is not just in observation matrices but also in mapping matrices. Moreover, the Tikhonov regularization is widely used in plenty…

Numerical Analysis · Mathematics 2022-11-14 F. Han , Y. Wei , P. Xie

In this paper, we introduce a novel, data-driven approach for solving high-dimensional Bayesian inverse problems based on partial differential equations (PDEs), called Weak Neural Variational Inference (WNVI). The method complements real…

Machine Learning · Statistics 2024-07-31 Vincent C. Scholz , Yaohua Zang , Phaedon-Stelios Koutsourelakis

We have shown that the vector of the point spread function (PSF) lexicographical presentation belongs to the left side conjugated null space (NS) of the autoregression (AR) matrix operator on condition the AR parameters are common for…

Computer Vision and Pattern Recognition · Computer Science 2015-03-02 Yuriy A. Bunyak , Roman N. Kvetnyy , Olga Yu. Sofina

This paper introduces new solvers for efficiently computing solutions to large-scale inverse problems with group sparsity regularization, including both non-overlapping and overlapping groups. Group sparsity regularization refers to a type…

Numerical Analysis · Mathematics 2023-06-16 Julianne Chung , Malena Sabaté Landman

This paper discusses weighted tensor Golub-Kahan-type bidiagonalization processes using the t-product. This product was introduced in [M. E. Kilmer and C. D. Martin, Factorization strategies for third order tensors, Linear Algebra Appl.,…

Numerical Analysis · Mathematics 2021-09-10 Lothar Reichel , Ugochukwu O Ugwu

The L1 norm regularized least squares method is often used for finding sparse approximate solutions and is widely used in 1-D signal restoration. Basis pursuit denoising (BPD) performs noise reduction in this way. However, the shortcoming…

Computer Vision and Pattern Recognition · Computer Science 2020-01-30 Nantheera Anantrasirichai , Rencheng Zheng , Ivan Selesnick , Alin Achim

We consider the problem of estimating the slope function in a functional regression with a scalar response and a functional covariate. This central problem of functional data analysis is well known to be ill-posed, thus requiring a…

Methodology · Statistics 2016-10-05 Anirvan Chakraborty , Victor M. Panaretos

There is extensive mathematical literature on the inverse problem of deautoconvolution for a function with support in the unit interval $[0,1] \subset \mathbb R$, but little is known about the multidimensional situation. This article tries…

Numerical Analysis · Mathematics 2022-10-26 Yu Deng , Bernd Hofmann , Frank Werner

In this paper, we are interested to an inverse Cauchy problem governed by the Stokes equation, called the data completion problem. It consists in determining the unspecified fluid velocity, or one of its components over a part of its…

Numerical Analysis · Mathematics 2021-12-30 A. Chakib , A. Nachaoui , M. Nachaoui , H. Ouaissa

We consider the efficient minimization of a nonlinear, strictly convex functional with $\ell_1$-penalty term. Such minimization problems appear in a wide range of applications like Tikhonov regularization of (non)linear inverse problems…

Optimization and Control · Mathematics 2016-04-12 Esther Hans , Thorsten Raasch

We study inexact fixed-point proximity algorithms for solving a class of sparse regularization problems involving the $\ell_0$ norm. Specifically, the $\ell_0$ model has an objective function that is the sum of a convex fidelity term and a…

Optimization and Control · Mathematics 2024-04-30 Ronglong Fang , Yuesheng Xu , Mingsong Yan

We study sparse solutions of optimal control problems governed by PDEs with uncertain coefficients. We propose two formulations, one where the solution is a deterministic control optimizing the mean objective, and a formulation aiming at…

Numerical Analysis · Mathematics 2018-11-20 Chen Li , Georg Stadler

This paper introduces a weighted generalized inverse framework for Fourier extensions, designed to suppress spurious oscillations in the extended region while maintaining high approximation accuracy on the original interval. By formulating…

Numerical Analysis · Mathematics 2026-01-13 Zhenyu Zhao , Yanfei Wang , Anatoly G. Yagola , Xusheng Li

The robust low-rank tensor completion problem addresses the challenge of recovering corrupted high-dimensional tensor data with missing entries, outliers, and sparse noise commonly found in real-world applications. Existing methodologies…

Machine Learning · Statistics 2026-04-16 Biswarup Karmakar , Ratikanta Behera

We provide a modified augmented Lagrange method coupled with a Tikhonov regularization for solving ill-posed state-constrained elliptic optimal control problems with sparse controls. We consider a linear quadratic optimal control problem…

Optimization and Control · Mathematics 2017-08-14 Veronika Karl , Frank Pörner