Iterative Tikhonov regularization of tensor equations based on the Arnoldi process and some of its generalizations

Autor: Lothar Reichel, Fatemeh Panjeh Ali Beik, Mehdi Najafi–Kalyani
Rok vydání: 2020
Předmět:
Zdroj: Applied Numerical Mathematics. 151:425-447
ISSN: 0168-9274
DOI: 10.1016/j.apnum.2020.01.011
Popis: We consider the solution of linear discrete ill-posed systems of equations with a certain tensor product structure. Two aspects of this kind of problems are investigated: They are transformed to large linear systems of equations and the conditioning of the matrix of the latter system is analyzed. Also, the distance of this matrix to symmetry and skew-symmetry is investigated. The aim of our analysis is to shed light on properties of linear discrete ill-posed problems and to study the feasibility of using Krylov subspace iterative methods in conjunction with Tikhonov regularization to solve Sylvester tensor equations with severely ill-conditioned coefficient matrices. The performance of several proposed algorithms is studied numerically. Applications include color image restoration and the solution of a 3D radiative transfer equation that is discretized by a Chebyshev collocation spectral method.
Databáze: OpenAIRE