4 papers
An adaptive framework for first-order gradient methods
Xiaozhe Hu, Sara Pollock, Zhongqin Xue +1
Gradient methods are widely used in optimization problems. In practice, while the smoothness parameter can be estimated utilizing techniques such as backtracking, estimating the st…
A unified spatiotemporal formulation with physics-preserving structure for time-dependent convection-diffusion problems
James H. Adler, Xiaozhe Hu, Seulip Lee
We propose a unified four-dimensional (4D) spatiotemporal formulation for time-dependent convection-diffusion problems that preserves underlying physical structures. By treating ti…
Error Estimates for the Arnoldi Approximation of a Matrix Square Root
James H. Adler, Xiaozhe Hu, Wenxiao Pan +1
The Arnoldi process provides an efficient framework for approximating functions of a matrix applied to a vector, i.e., of the form , by repeated matrix-vector multiplic…
Parameter-robust preconditioner for Stokes-Darcy coupled problem with Lagrange multiplier
Xiaozhe Hu, Miroslav Kuchta, Kent-Andre Mardal +1
In this paper, we propose a parameter-robust preconditioner for the coupled Stokes-Darcy problem equipped with various boundary conditions, enforcing the mass conservation at the i…