29 citations · 37 across the 19 of their papers we have counts for
19 papers · 1 filter
Numerical solution of elliptic distributed optimal control problems with boundary value tracking
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We consider some boundary value tracking optimal control problem constrained by a Neumann boundary value problem for some elliptic partial differential equation where the control a…
State-based approach to the numerical solution of Dirichlet boundary optimal control problems for the Laplace equation
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We investigate the Dirichlet boundary control of the Laplace equation, considering the control in , which is the natural space for Dirichlet data when the stat…
State-based nested iteration solution of optimal control problems with PDE constraints
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We consider an abstract framework for the numerical solution of optimal control problems (OCPs) subject to partial differential equations (PDEs). Examples include not only the dist…
Robust finite element solvers for distributed hyperbolic optimal control problems
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We propose, analyze, and test new robust iterative solvers for systems of linear algebraic equations arising from the space-time finite element discretization of reduced optimality…
Parallel iterative solvers for discretized reduced optimality systems
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We propose, analyze, and test new iterative solvers for large-scale systems of linear algebraic equations arising from the finite element discretization of reduced optimality syste…
Mass-lumping discretization and solvers for distributed elliptic optimal control problems
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
The purpose of this paper is to investigate the effects of the use of mass-lumping in the finite element discretization of the reduced first-order optimality system arising from a…
An adaptive finite element method for distributed elliptic optimal control problems with variable energy regularization
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We analyze the finite element discretization of distributed elliptic optimal control problems with variable energy regularization, where the usual norm regularization term…
Robust finite element discretization and solvers for distributed elliptic optimal control problems
Ulrich Langer, Richard Löscher, Olaf Steinbach +1
We consider standard tracking-type, distributed elliptic optimal control problems with regularization, and their finite element discretization. We are investigating the …
Robust space-time finite element error estimates for parabolic distributed optimal control problems with energy regularization
Ulrich Langer, Olaf Steinbach, Huidong Yang
We consider space-time tracking optimal control problems for linear para\-bo\-lic initial boundary value problems that are given in the space-time cylinder , and…
Space-time finite element methods for the initial temperature reconstruction
Ulrich Langer, Olaf Steinbach, Fredi Tröltzsch +1
This work is devoted to the reconstruction of the initial temperature in the backward heat equation using the space-time finite element method on fully unstructured space-time simp…
Robust discretization and solvers for elliptic optimal control problems with energy regularization
Ulrich Langer, Olaf Steinbach, Huidong Yang
We consider the finite element discretization and the iterative solution of singularly perturbed elliptic reaction-diffusion equations in three-dimensional computational domains. T…
Unstructured space-time finite element methods for optimal control of parabolic equations
Ulrich Langer, Olaf Steinbach, Fredi Tröltzsch +1
This work presents and analyzes space-time finite element methods on fully unstructured simplicial space-time meshes for the numerical solution of parabolic optimal control problem…
Unstructured Space-Time Finite Element Methods for Optimal Sparse Control of Parabolic Equations
Ulrich Langer, Olaf Steinbach, Fredi Tröltzsch +1
We consider a space-time finite element method on fully unstructured simplicial meshes for optimal sparse control of semilinear parabolic equations. The objective is a combination…
BDDC preconditioners for a space-time finite element discretization of parabolic problems
Ulrich Langer, Huidong Yang
This paper deals with balanced domain decomposition by constraints (BDDC) method for solving large-scale linear systems of algebraic equations arising from the space-time finite el…
Numerical simulation of parabolic moving and growing interface problems using small mesh deformation
Ulrich Langer, Huidong Yang
In this work, we develop a cutting method for solving problems with moving and growing interfaces in 3D. This new method is able to resolve large displacement or deformation of imm…
An algebraic multigrid method for quadratic finite element equations of elliptic and saddle point systems in 3D
Huidong Yang
In this work, we propose a robust and easily implemented algebraic multigrid method as a stand-alone solver or a preconditioner in Krylov subspace methods for solving either symmet…
A note on robust preconditioners for monolithic fluid-structure interaction systems of finite element equations
U. Langer, H. Yang
In this note, we consider preconditioned Krylov subspace methods for discrete fluid-structure interaction problems with a nonlinear hyperelastic material model and covering a large…
Numerical Simulation of Fluid-Structure Interaction Problems with Hyperelastic Models: A Monolithic Approach
Ulrich Langer, Huidong Yang
In this paper, we consider a monolithic approach to handle coupled fluid-structure interaction problems with different hyperelastic models in an all-at-once manner. We apply Newton…
Numerical Simulation of Fluid-Structure Interaction Problems with Hyperelastic Models I: A Partitioned Approach
Ulrich Langer, Huidong Yang
In this work, we consider fluid-structure interaction simulation with nonlinear hyperelastic models in the solid part. We use a partitioned approach to deal with the coupled nonlin…