| Projection methods based on wavelet functions combine optimal convergence rates with algorithmic eeciency. The proofs in this paper utilize the approximation properties of wavelets and results from the general theory of regularization methods. Moreover, adaptive strategies can be incorporated still leading to optimal convergence rates for the resulting algorithms. The so-called wavelet-vaguel...

In this paper we reduce a free boundary problem from heat transfer to a weakly Singular Volterra  integral equation of the first kind. Since the first kind integral equation is ill posed, and an appropriate method for such ill posed problems is based on wavelets, then we apply the Chebyshev wavelets to solve the integral equation. Numerical implementation of the method is illustrated by two ben...

Recently, the metrics of Ky Fan and Prokhorov were introduced as a tool for studying convergence in stochastic ill-posed problems. In this work, we show that the Bayesian approach to linear inverse problems can be examined in the new framework as well. We consider the finitedimensional case where the measurements are disturbed by an additive normal noise and the prior distribution is normal. Co...

To assess the quality of solutions in stochastic inverse problems, a proper measure for the distance of random variables is essential. The aim of this note is the comparison of the metrics of Ky Fan and Prokhorov with other concepts such as expected values, probability estimates and almost sure convergence. In ill-posed problems one aims to find an appropriate solution x† to an equation of the ...

The paper is concerned with the solution of nonlinear ill-posed problems by methods that utilise the second derivative. A general predictor{corrector approach is developed; one which avoids solving quadratic equations during the iteration process. Combining regularisation of each iteration step with an adequate stopping condition leads to a general regularisation scheme for nonlinear equations....

The inverse problem we consider in this tutorial is to determine the shape of an obstacle from the knowledge of the far field pattern for scattering of time-harmonic plane waves. In the first part we will concentrate on the issue of uniqueness, i.e., we will investigate under what conditions an obstacle and its boundary condition can be identified from a knowledge of its far field pattern for i...

A new approach to solving linear ill-posed problems is proposed. The approach consists of solving a Cauchy problem for a linear operator equation and proving that this problem has a global solution whose limit at infinity solves the original linear equation.

Ill-posed inverse problems are widely en countered in computer vision, examples include shape from shading, surface reconstruction from sparse data and optic flow. Unique sol utions to these problems are conventionally found by minimizing an objective function regu larized by a smoothness constraint. However, objective functions of this form often contain many local minima, making it difficult ...