When simulating a mechanism from science or engineering, or an industrial process, one is frequently required to construct a mathematical model, and then resolve this model …
Our times can be characterized by, among many other attributes, the seemingly increasing speed of everything. Within science, it has led to the publication explosion, which reflects the …
The solution of quadratic or locally quadratic extremum problems subject to linear (ized) constraints gives rise to linear systems in saddle point form. This is true whether in the …
T Gergelits, KA Mardal, BF Nielsen, Z Strakos - SIAM Journal on Numerical …, 2019 - SIAM
In IMA J. Numer. Anal., 29 (2009), pp. 24--42, Nielsen, Tveito, and Hackbusch study the operator generated by using the inverse of the Laplacian as the preconditioner for second …
Computationally solving an optimisation problem on Hilbert spaces requires discretisation and the application of an optimisation method to the resulting finite-dimensional problem. In …
T Gergelits, Z Strakoš - Numerical Algorithms, 2014 - Springer
The conjugate gradient method (CG) for solving linear systems of algebraic equations represents a highly nonlinear finite process. Since the original paper of Hestenes and Stiefel …
We propose and analyze two strategies for preconditioning linear operator equations that arise in PDE constrained optimal control in the framework of conjugate gradient methods …
A Boquet-Pujadas… - IEEE Transactions on …, 2022 - ieeexplore.ieee.org
From meteorology to medical imaging and cell mechanics, many scientific domains use inverse problems (IPs) to extract physical measurements from image movement. To this end …
KA Mardal, BF Nielsen, M Nordaas - BIT Numerical Mathematics, 2017 - Springer
Regularization robust preconditioners for PDE-constrained optimization problems have been successfully developed. These methods, however, typically assume observation data …