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Inverse problems are often ill-posed, with solutions that depend sensitively on data. In any numerical approach to the solution of such problems, regularization of some form is needed to counteract the resulting instability. This paper is…

Numerical Analysis · Mathematics 2009-09-14 S. L. Cotter , M. Dashti , A. M. Stuart

Recently, the stochastic asymptotical regularization (SAR) has been developed in (\emph{Inverse Problems}, 39: 015007, 2023) for the uncertainty quantification of the stable approximate solution of linear ill-posed inverse problems. In this…

Numerical Analysis · Mathematics 2024-08-27 Haie Long , Ye Zhang

We consider the problem of localizing the source using range and range-difference measurements. Both the problems are non-convex and non-smooth and are challenging to solve. In this paper, we develop an iterative algorithm - Source…

Signal Processing · Electrical Eng. & Systems 2020-02-10 R. Jyothi , P. Babu

In this paper, we address the problem of approximating solutions of ill-posed problems using mollification. We quickly review existing mollification regularization methods and provide two new approximate solutions to a general ill-posed…

Numerical Analysis · Mathematics 2020-05-05 Walter Cedric Simo Tao Lee

We study the linear ill-posed inverse problem with noisy data in the statistical learning setting. Approximate reconstructions from random noisy data are sought with general regularization schemes in Hilbert scale. We discuss the rates of…

Statistics Theory · Mathematics 2024-04-09 Abhishake Rastogi , Peter Mathé

A wide class of regularization problems in machine learning and statistics employ a regularization term which is obtained by composing a simple convex function \omega with a linear transformation. This setting includes Group Lasso methods,…

Machine Learning · Computer Science 2011-04-11 Andreas Argyriou , Charles A. Micchelli , Massimiliano Pontil , Lixin Shen , Yuesheng Xu

In this paper, we deal with the inverse source problem of determining a source in a time fractional diffusion equation where data are given at a fixed time. This problem is ill-posed, i.e., the solution does not depend continuously on the…

Probability · Mathematics 2016-11-29 Tuan Nguyen Huy , Erkan Nane

Ill-posed linear inverse problems appear frequently in various signal processing applications. It can be very useful to have theoretical characterizations that quantify the level of ill-posedness for a given inverse problem and the degree…

Signal Processing · Electrical Eng. & Systems 2023-04-26 Justin P. Haldar

In this paper we investigate the problem of identifying the source term in an elliptic system from a single noisy measurement couple of the Neumann and Dirichlet data. A variational method of Tikhonov-type regularization with specific…

Analysis of PDEs · Mathematics 2019-03-15 Michael Hinze , Bernd Hofmann , Tran Nhan Tam Quyen

Our focus is on the stable approximate solution of linear operator equations based on noisy data by using $\ell^1$-regularization as a sparsity-enforcing version of Tikhonov regularization. We summarize recent results on situations where…

Functional Analysis · Mathematics 2017-11-27 Daniel Gerth , Bernd Hofmann

Many physical problems can be formulated as operator equations of the form Au = f. If these operator equations are ill-posed, we then resort to finding the approximate solutions numerically. Ill-posed problems can be found in the fields of…

Numerical Analysis · Mathematics 2016-11-11 Suresh B. Srinivasamurthy

Tikhonov regularization is one of the most commonly used methods of regularization of ill-posed problems. In the setting of finite element solutions of elliptic partial differential control problems, Tikhonov regularization amounts to…

Numerical Analysis · Mathematics 2016-09-19 Erik Burman , Peter Hansbo , Mats Larson

This paper addresses the problem of sound-source localization from time-delay estimates using arbitrarily-shaped non-coplanar microphone arrays. A novel geometric formulation is proposed, together with a thorough algebraic analysis and a…

Sound · Computer Science 2014-08-12 Xavier Alameda-Pineda , Radu Horaud

This paper is concerned with a novel regularisation technique for solving linear ill-posed operator equations in Hilbert spaces from data that is corrupted by white noise. We combine convex penalty functionals with extreme-value statistics…

Statistics Theory · Mathematics 2012-04-03 Klaus Frick , Philipp Marnitz , Axel Munk

There are various inverse problems -- including reconstruction problems arising in medical imaging -- where one is often aware of the forward operator that maps variables of interest to the observations. It is therefore natural to ask…

Image and Video Processing · Electrical Eng. & Systems 2020-06-23 Jaweria Amjad , Zhaoyan Lyu , Miguel R. D. Rodrigues

We propose a physics-based regularization technique for function learning, inspired by statistical mechanics. By drawing an analogy between optimizing the parameters of an interpolator and minimizing the energy of a system, we introduce…

Machine Learning · Computer Science 2025-08-20 Abhisek Ganguly , Alessandro Gabbana , Vybhav Rao , Sauro Succi , Santosh Ansumali

We explore the possibility for using boundary data to identify sources in elliptic PDEs. Even though the associated forward operator has a large null space, it turns out that box constraints, combined with weighted sparsity regularization,…

Numerical Analysis · Mathematics 2023-03-06 Ole Løseth Elvetun , Bjørn Fredrik Nielsen

In this manuscript, a purely data driven statistical regularization method is proposed for extracting the information from big data with randomly distributed noise. Since the variance of the noise maybe large, the method can be regarded as…

Numerical Analysis · Mathematics 2021-02-19 Jin Cheng , Jiantang Zhang , Min Zhong

Upon the recent development of the quasi-reversibility method for terminal value parabolic problems in \cite{Nguyen2019}, it is imperative to investigate the convergence analysis of this regularization method in the stochastic setting. In…

Analysis of PDEs · Mathematics 2020-08-13 Nguyen Huy Tuan , Vo Anh Khoa , Phan Thi Khanh Van , Vo Van Au

This paper is concerned with backward problem for nonlinear space fractional diffusion with additive noise on the right-hand side and the final value. To regularize the instable solution, we develop some new regularized method for solving…

Analysis of PDEs · Mathematics 2016-12-19 Erkan Nane , Nguyen Huy Tuan