68 citations · 177 across the 14 of their papers we have counts for
6 papers · 1 filter
Controllability of ensembles of linear dynamical systems
Michael Schönlein, Uwe Helmke
We investigate the task of controlling ensembles of initial and terminal state vectors of parameter-dependent linear systems by applying parameter-independent open loop controls. N…
A Lie-Group Approach to Rigid Image Registration
Martin Schröter, Uwe Helmke, Otto Sauer
The task of image restration is to find the spatial correspondence of two or more given images. In this paper we assume that the correspondence is given either by an Euclidean, or…
Riemannian optimization on tensor products of Grassmann manifolds: Applications to generalized Rayleigh-quotients
O. Curtef, G. Dirr, U. Helmke
We introduce a generalized Rayleigh-quotient on the tensor product of Grassmannians enabling a unified approach to well-known optimization tasks from different areas of numerical l…
Newton's method on Graßmann manifolds
Uwe Helmke, Knut Hüper, Jochen Trumpf
A general class of Newton algorithms on Graßmann and Lagrange-Graßmann manifolds is introduced, that depends on an arbitrary pair of local coordinates. Local quadratic convergence…
Output Feedback Pole Assignment for Transfer Functions with Symmetries
Uwe Helmke, Joachim Rosenthal, Alex Wang
This paper studies the problem of pole assignment for symmetric and Hamiltonian transfer functions. A necessary and sufficient condition for pole assignment by complex symmetric ou…
Output Feedback Invariants
M. S. Ravi, Joachim Rosenthal, Uwe Helmke
The paper is concerned with the problem of determining a complete set of invariants for output feedback. Using tools from geometric invariant theory it is shown that there exists a…