English
Related papers

Related papers: A regularization operator for source identificatio…

200 papers

In this contribution we show sufficient conditions for simultaneous unique identification of unknown spacewise coefficients and heat source in a parabolic partial differential equation given additional final time measurements. Our approach…

Numerical Analysis · Mathematics 2012-10-30 Adriano De Cezaro , Fabiana Travessini De Cezaro

We consider the linear second order PDO's $$ \mathscr{L} = \mathscr{L}_0 - \partial_t : = \sum_{i,j =1}^N \partial_{x_i}(a_{i,j} \partial_{x_j} ) - \sum_{j=i}^N b_j \partial_{x_j} - \partial _t,$$and assume that $\mathscr{L}_0$ has…

Analysis of PDEs · Mathematics 2019-03-21 Alessia E. Kogoj

This paper is concerned with the introduction of Tikhonov regularization into least squares approximation scheme on $[-1,1]$ by orthonormal polynomials, in order to handle noisy data. This scheme includes interpolation and…

Numerical Analysis · Mathematics 2021-08-31 Congpei An , Hao-Ning Wu

The present paper establishes a certain duality between the Dirichlet and Regularity problems for elliptic operators with $t$-independent complex bounded measurable coefficients ($t$ being the transversal direction to the boundary). To be…

Analysis of PDEs · Mathematics 2014-07-01 Steve Hofmann , Carlos Kenig , Svitlana Mayboroda , Jill Pipher

In this paper we investigate the problem of recovering the source term in an elliptic system from a measurement of the state on a part of the boundary. For the particular interest in reconstructing probably discontinuous sources, we use the…

Numerical Analysis · Mathematics 2020-01-08 Michael Hinze , Tran Nhan Tam Quyen

The purpose of this work is the study of solution techniques for problems involving fractional powers of symmetric coercive elliptic operators in a bounded domain with Dirichlet boundary conditions. These operators can be realized as the…

Numerical Analysis · Mathematics 2013-02-05 Ricardo H. Nochetto , Enrique Otarola , Abner J. Salgado

Accurate determination of the regularization parameter in inverse problems still represents an analytical challenge, owing mainly to the considerable difficulty to separate the unknown noise from the signal. We present a new approach for…

Numerical Analysis · Mathematics 2019-07-24 Eitan Levin , Alexander Y. Meltzer

This paper focuses on the analysis of conforming virtual element methods for general second-order linear elliptic problems with rough source terms and applies it to a Poisson inverse source problem with rough measurements. For the forward…

Numerical Analysis · Mathematics 2023-02-20 Rekha Khot , Neela Nataraj , Nitesh Verma

An adaptive regularization strategy for stabilizing Newton-like iterations on a coarse mesh is developed in the context of adaptive finite element methods for nonlinear PDE. Existence, uniqueness and approximation properties are known for…

Numerical Analysis · Mathematics 2015-01-27 Sara Pollock

We study an infinite-dimensional optimization problem that aims to identify the Nemytskii operator in the nonlinear part of a prototypical semilinear elliptic partial differential equation (PDE) which minimizes the distance between the…

Optimization and Control · Mathematics 2024-02-05 Constantin Christof , Julia Kowalczyk

Regularizing neural networks is important for anticipating model behavior in regions of the data space that are not well represented. In this work, we propose a regularization technique for enforcing a level of smoothness in the mapping…

Machine Learning · Computer Science 2025-03-05 Ali Hasan , Haoming Yang , Yuting Ng , Vahid Tarokh

We present a new inner-outer iterative algorithm for edge enhancement in imaging problems. At each outer iteration, we formulate a Tikhonov-regularized problem where the penalization is expressed in the 2-norm and involves a regularization…

Numerical Analysis · Mathematics 2020-12-30 Silvia Gazzola , Misha E. Kilmer , James G. Nagy , Oguz Semerici , Eric L. Miller

Tikhonov regularization is a common technique used when solving poorly behaved optimization problems. Often, and with good reason, this technique is applied by practitioners in an ad hoc fashion. In this note, we systematically illustrate…

Optimization and Control · Mathematics 2022-12-16 J. Adriazola

A number of regularization methods for discrete inverse problems consist in considering weighted versions of the usual least square solution. However, these so-called filter methods are generally restricted to monotonic transformations,…

Statistics Theory · Mathematics 2011-05-05 Paul Rochet

Overdetermined systems of first kind integral equations appear in many applications. When the right-hand side is discretized, the resulting finite-data problem is ill-posed and admits infinitely many solutions. We propose a numerical method…

Numerical Analysis · Mathematics 2023-07-26 Patricia Díaz de Alba , Luisa Fermo , Federica Pes , Giuseppe Rodriguez

This paper introduces a new strategy for setting the regularization parameter when solving large-scale discrete ill-posed linear problems by means of the Arnoldi-Tikhonov method. This new rule is essentially based on the discrepancy…

Numerical Analysis · Mathematics 2013-07-02 Silvia Gazzola , Paolo Novati , Maria Rosaria Russo

A space-time interface-fitted approximation of an inverse source problem for the advection-diffusion equation with moving subdomains is investigated. The problem is reformulated as an optimization problem using Tikhonov regularization. A…

Numerical Analysis · Mathematics 2025-02-11 Thi Thanh Mai Ta , Quang Huy Nguyen , Dinh Nho Hào

Regularizing a linear ill-posed operator equation can be achieved by manipulating the spectrum of the operator's pseudo-inverse. Tikhonov regularization and spectral cutoff are well-known techniques within this category. This paper…

Numerical Analysis · Mathematics 2026-02-11 Martin Sæbye Carøe , Mirza Karamehmedović , Pierre Maréchal

In this paper, we study the stochastic convergence of regularized solutions for backward heat conduction problems. These problems are recognized as ill-posed due to the exponential decay of eigenvalues associated with the forward problems.…

Numerical Analysis · Mathematics 2023-11-08 Zhongjian Wang , Wenlong Zhang , Zhiwen Zhang

In this paper, we deal with nonlinear ill-posed problems involving monotone operators and consider Lavrentiev's regularization method. This approach, in contrast to Tikhonov's regularization method, does not make use of the adjoint of the…

Numerical Analysis · Mathematics 2016-04-20 Bernd Hofmann , Barbara Kaltenbacher , Elena Resmerita