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Winter Term 2014/15, Doctoral School Events
2014-11-14 Doctoral School Seminar (Inst. Mathematik, Heinrichstr. 36, Seminarraum 11.33, 13:00—16:00, KFU)
Daniel Kraft (KFU, advisor W. Ring): Gradient Descent and Gradient Flow Methods in the Context of Shape Optimisation

Abstract: We present a toy model for image segmentation and describe a gradient descent method for level-set based shape optimisation with that model. We point out why this method is inefficient, in particular when sharp edges are present in the considered image.
To increase performance, we propose a new method that corresponds to a gradient flow. This method does not need derivatives of the image data, which makes it potentially more stable than alternatives. This novel approach works very well in practice and has a (partial) theoretical justification. It can also be used in a hybrid method combining domain evolution methods with topological derivatives. [hide abstract]

Philip Trautmann (KFU, advisor K. Kunisch): Measure valued optimal control problems governed by the linear wave equation [show abstract]
Florian Greinecker (TU, advisor P. Grabner): On the 2-abelian complexity of Thue-Morse subwords [show abstract]
Christoph Koch (TU, advisor M. Kang): Boostrap percolation on random hypergraphs [show abstract]
2014-12-12 Doctoral School Seminar (Seminarraum 2 des Instituts für Geometrie, Kopernikusgasse 24, 10:30—13:00, TU)
Johannes Cuno (TU, advisor W. Woess): Random Walks on Baumslag-Solitar Groups [show abstract]
Bumrungsak Phuenaree (KFU, advisor F. Kappel): Traditional Sensitivity Functions in Nonlinear Maximum Likelihood Problems [show abstract]
Roswitha Rissner (TU, advisor S. Frisch): Null ideal of a matrix [show abstract]
Martin Kanitsar (KFU, advisor M. Hintermüller): Shape optimization in fluid dynamics [show abstract]
2015-01-30 Doctoral School Seminar (Seminarraum 2 des Instituts für Geometrie, Kopernikusgasse 24, 13:00—14:00, TU)
Dexter Jane Indong (KFU, advisor F. Kappel): Sensitivity analysis and parameter identifiability of a within-host malaria transmission model [show abstract]
Stefan Rosenberger (KFU, advisor K. Fellner): Optimization of AEgIS [show abstract]