Speaker
Description
In this talk, I will present iDARR, a scalable iterative Data-Adaptive RKHS Regularization method for solving ill-posed linear inverse problems. This method searches for solutions in subspaces where the true solution can be identified, with the data-adaptive reproducing kernel Hilbert space (RKHS) penalizing the spaces of small singular values. At the core of the method is a new generalized Golub-Kahan bidiagonalization procedure that recursively constructs orthonormal bases for a sequence of RKHS-restricted Krylov subspaces. The method is scalable, with a complexity of O(kmn) for m-by-n matrices, where k denotes the number of iterations. Numerical tests on the Fredholm integral equation and 2D image deblurring demonstrate that it outperforms the widely used L^2 and l^2 norms, consistently producing stable and accurate solutions that converge when the noise level decreases.