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This paper analyzes a time-stepping discontinuous Galerkin method for fractional diffusion-wave problems. This method uses piecewise constant functions in the temporal discretization and continuous piecewise linear functions in the spatial…

Numerical Analysis · Mathematics 2019-08-27 Binjie Li , Tao Wang , Xiaoping Xie

The forward and inverse wavelet transform using the continuous Morlet basis may be symmetrized by using an appropriate normalization factor. The loss of response due to wavelet truncation is addressed through a renormalization of the…

Data Analysis, Statistics and Probability · Physics 2012-02-28 Robert W. Johnson

The inversion of electromagnetic induction data to a conductivity profile is an ill-posed problem. Regularization improves the stability of the inversion and, based on Occam's razor principle, a smoothing constraint is typically used.…

Geophysics · Physics 2021-05-19 Wouter Deleersnyder , Benjamin Maveau , Thomas Hermans , David Dudal

A stochastic inverse heat transfer problem is formulated to infer the transient heat flux, treated as an unknown Neumann boundary condition. Therefore, an Ensemble-based Simultaneous Input and State Filtering as a Data Assimilation…

Numerical Analysis · Mathematics 2024-03-01 Kabir Bakhshaei , Umberto Emil Morelli , Giovanni Stabile , Gianluigi Rozza

Inverse scattering problems of the reconstructions of physical properties of a medium from boundary measurements are substantially challenging ones. This work aims to verify the performance on experimental data of a newly developed…

The rational covariance extension problem to determine a rational spectral density given a finite number of covariance lags can be seen as a matrix completion problem to construct an infinite-dimensional positive-definite Toeplitz matrix…

Optimization and Control · Mathematics 2012-08-31 Anders Lindquist , Giorgio Picci

A high-accuracy time discretization is discussed to numerically solve the nonlinear fractional diffusion equation forced by a space-time white noise. The main purpose of this paper is to improve the temporal convergence rate by modifying…

Numerical Analysis · Mathematics 2021-05-04 Xing Liu

In this paper, we consider an inverse space-dependent source problem for a time-fractional diffusion equation. To deal with the ill-posedness of the problem, we transform the problem into an optimal control problem with total variational…

Optimization and Control · Mathematics 2025-01-15 Bin Fan

We consider a one-dimensional one-phase inverse Stefan problem for the heat equation. It consists in recovering a boundary influx condition from the knowledge of the position of the moving front, and the initial state. We derived a…

Analysis of PDEs · Mathematics 2020-02-24 Chifaa Ghanmi , Saloua Mani-Aouadi , Faouzi Triki

In this article, a finite element model is implemented to analyze hydro-thermal convective flow in a porous medium. The mathematical model encompasses Darcy's law for incompressible fluid behavior, which is coupled with a…

Numerical Analysis · Mathematics 2024-02-27 S. M. Mallikarjunaiah , Dambaru Bhatta

We study a Bayesian approach to recovering the initial condition for the heat equation from noisy observations of the solution at a later time. We consider a class of prior distributions indexed by a parameter quantifying "smoothness" and…

Statistics Theory · Mathematics 2013-03-04 B. T. Knapik , A. W. van der Vaart , J. H. van Zanten

The present paper analyzes a spectral regularization of a time-reversed reaction-diffusion problem with globally and locally Lipschitz nonlinearities. This type of inverse and ill-posed problems arises in a variety of real-world…

Analysis of PDEs · Mathematics 2021-09-08 Vo Anh Khoa

This work deals with the problem of determining a non-homogeneous heat conductivity profile in a steady-state heat conduction boundary-value problem with mixed Dirichlet-Neumann boundary conditions over a bounded domain in $\mathbb{R}^n$,…

Numerical Analysis · Mathematics 2022-08-25 Angel A. Ciarbonetti , Sergio Idelsohn , Ruben D. Spies

In this paper we study the harmonic map heat flow problem for a radially symmetric case. The corresponding partial dfferential equation plays a key role in many analyses of harmonic map heat flow problems. We consider a basic discretization…

Numerical Analysis · Mathematics 2025-07-16 Nam Anh Nguyen , Arnold Reusken

Seismic inversion is a core problem in geophysical exploration, where traditional methods suffer from high computational costs and are susceptible to initial model dependence. In recent years, deep generative model-based seismic inversion…

Machine Learning · Computer Science 2026-03-17 Haofei Xu , Wei Cheng , Sizhe Li , Jie Xiong

We propose the use of $\ell_1$ regularization in a wavelet basis for the solution of linearized seismic tomography problems $Am=d$, allowing for the possibility of sharp discontinuities superimposed on a smoothly varying background. An…

Geophysics · Physics 2009-11-13 Ignace Loris , Guust Nolet , Ingrid Daubechies , F. A. Dahlen

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

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

In this paper we consider a stochastic heavy-ball method for solving linear ill-posed inverse problems. With suitable choices of the step-sizes and the momentum coefficients, we establish the regularization property of the method under {\it…

Numerical Analysis · Mathematics 2024-06-25 Qinian Jin , Yanjun Liu

We consider partitioned time integration for heterogeneous coupled heat equations. First and second order multirate, as well as time-adaptive Dirichlet-Neumann Waveform relaxation (DNWR) methods are derived. In 1D and for implicit Euler…

Numerical Analysis · Mathematics 2021-07-28 Peter Meisrimel , Azahar Monge , Philipp Birken
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