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Related papers: Methods of Solving Ill-Posed Problems

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For solving linear ill-posed problems regularization methods are required when the right hand side is with some noise. In the present paper regularized solutions are obtained by implicit iteration methods in Hilbert scales. % By exploiting…

Numerical Analysis · Mathematics 2015-05-20 Qinian Jin , Ulrich Tautenhahn

Linear inverse problems are ubiquitous. Often the measurements do not follow a Gaussian distribution. Additionally, a model matrix with a large condition number can complicate the problem further by making it ill-posed. In this case, the…

We shall investigate randomized algorithms for solving large-scale linear inverse problems with general regularizations. We first present some techniques to transform inverse problems of general form into the ones of standard form, then…

Numerical Analysis · Mathematics 2014-12-30 Hua Xiang , Jun Zou

The paper is devoted to well-posedness analysis and the numerical solution of a family of general elliptic mixed variational-hemivariational inequalities. Various mixed variational equations, mixed variational inequalities and mixed…

Numerical Analysis · Mathematics 2026-02-03 Weimin Han , Jianguo Huang , Yuan Yao

A characterization of a semilinear elliptic partial differential equation (PDE) on a bounded domain in $\mathbb{R}^n$ is given in terms of an infinite-dimensional dynamical system. The dynamical system is on the space of boundary data for…

Analysis of PDEs · Mathematics 2020-07-15 Margaret Beck , Graham Cox , Christopher Jones , Yuri Latushkin , Alim Sukhtayev

The aim of this paper is to investigate the use of an entropic projection method for the iterative regularization of linear ill-posed problems. We derive a closed form solution for the iterates and analyze their convergence behaviour both…

Optimization and Control · Mathematics 2020-01-29 Martin Burger , Elena Resmerita , Martin Benning

This paper establishes the local-in-time well-posedness of solutions to an approximating system constructed by mildly regularizing the dynamical sea-ice model of {\it W.D. Hibler, Journal of Physical Oceanography, 1979}. Our choice of…

Analysis of PDEs · Mathematics 2022-06-08 Xin Liu , Marita Thomas , Edriss S. Titi

The focus of this book is on the analysis of regularization methods for solving \emph{nonlinear inverse problems}. Specifically, we place a strong emphasis on techniques that incorporate supervised or unsupervised data derived from prior…

Optimization and Control · Mathematics 2025-06-24 Clemens Kirisits , Bochra Mejri , Sergei Pereverzev , Otmar Scherzer , Cong Shi

This paper discusses the error and cost aspects of ill-posed integral equations when given discrete noisy point evaluations on a fine grid. Standard solution methods usually employ discretization schemes that are directly induced by the…

Numerical Analysis · Mathematics 2025-04-04 Michael Griebel , Tim Jahn

Subspace recycling techniques have been used quite successfully for the acceleration of iterative methods for solving large-scale linear systems. These methods often work by augmenting a solution subspace generated iteratively by a known…

Numerical Analysis · Mathematics 2021-05-18 Ronny Ramlau , Kirk M. Soodhalter , Victoria Hutterer

In this paper, we establish an initial theory regarding the Second Order Asymptotical Regularization (SOAR) method for the stable approximate solution of ill-posed linear operator equations in Hilbert spaces, which are models for linear…

Numerical Analysis · Mathematics 2018-08-28 Ye Zhang , Bernd Hofmann

An unsteady problem is considered for a space-fractional equation in a bounded domain. A first-order evolutionary equation involves the square root of an elliptic operator of second order. Finite element approximation in space is employed.…

Numerical Analysis · Mathematics 2015-10-29 Petr N. Vabishchevich

A version of the Dynamical Systems Method (DSM) for solving ill-conditioned linear algebraic systems is studied in this paper. An {\it a priori} and {\it a posteriori} stopping rules are justified. An iterative scheme is constructed for…

Numerical Analysis · Mathematics 2008-03-31 N. S. Hoang , A. G. Ramm

In this paper, the concept of matrix splitting is introduced to solve a large sparse ill-posed linear system via Tikhonov's regularization. In the regularization process, we convert the ill-posed system to a well-posed system. The…

Numerical Analysis · Mathematics 2020-04-15 Ashish Kumar Nandi , Jajati Keshari Sahoo

Most of the literature on the solution of linear ill-posed operator equations, or their discretization, focuses only on the infinite-dimensional setting or only on the solution of the algebraic linear system of equations obtained by…

Numerical Analysis · Mathematics 2018-12-05 Ronny Ramlau , Lothar Reichel

Many inverse problems are concerned with the estimation of non-negative parameter functions. In this paper, in order to obtain non-negative stable approximate solutions to ill-posed linear operator equations in a Hilbert space setting, we…

Numerical Analysis · Mathematics 2020-02-21 Ye Zhang , Bernd Hofmann

A version of the Dynamical Systems Method (DSM) for solving ill-posed nonlinear equations with monotone operators in a Hilbert space is studied in this paper. An a posteriori stopping rule, based on a discrepancy-type principle is proposed…

Numerical Analysis · Mathematics 2015-05-13 N. S. Hoang , A. G. Ramm

A review of the authors's results is given. Several methods are discussed for solving nonlinear equations $F(u)=f$, where $F$ is a monotone operator in a Hilbert space, and noisy data are given in place of the exact data. A discrepancy…

Numerical Analysis · Mathematics 2009-01-29 N. S. Hoang , A. G. Ramm

We introduce subgradient-based Lavrentiev regularisation of the form \begin{equation*} \mathcal{A}(u) + \alpha \partial \mathcal{R}(u) \ni f^\delta \end{equation*} for linear and nonlinear ill-posed problems with monotone operators…

Optimization and Control · Mathematics 2024-10-01 Markus Grasmair , Fredrik Hildrum

Despite the strong focus of regularization on ill-posed problems, the general construction of such methods has not been fully explored. Moreover, many previous studies cannot be clearly adapted to handle more complex scenarios, albeit the…

Analysis of PDEs · Mathematics 2016-10-20 Nguyen Huy Tuan , Vo Anh Khoa , Vo Van Au