TUHH / Institut für Mathematik / Vorträge

# Vorträge

Vorträge 1 bis 10 von 380 | Gesamtansicht

Datum Zeit Ort Vortrag
28.02.19 15:00 Am Schwarzenberg-Campus 3 (E), Raum 3.074 Bicentric Polygons
Yannick Mogge

I will give a short summary of my master thesis as well as a quick introduction of myself.
07.02.19 15:00 Am Schwarzenberg-Campus 3 (E), Raum 3.074 Accessibility Assistance for the Interactive Navigation of Texts [Masterarbeit]
06.02.19 13:30 Am Schwarzenberg-Campus 3 (E), Raum 3.074 Endliche Ausschnitte und Resolventen
Marko Lindner

Was wird aus (Pseudo-)Eigenwerten und -vektoren beim Abschneiden einer unendlichen Matrix? (Sie bleiben welche.)
Gibt es auch Aussagen in die umgekehrte Richtung?
Wie gut lassen sich diese Aussagen quantifizieren?
28.01.19 13:15 H0.08 Extrapolation spaces and Desch-Schappacher perturbations of bi-continuous semigroups*
Christian Budde, Bergische Universität Wuppertal, Arbeitsgruppe Funktionalanalysis

We construct extrapolation spaces for non-densely defined (weak) Hille--Yosida operators. In particular, we discuss extrapolation of bi-continuous semigroups. As an application we present a Desch--Schappacher type perturbation result for this kind of semigroups. This talk is based on joint work with B. Farkas.
24.01.19 13:30 D1.024 On eventual regularity properties of operator valued functions*
Marco Peruzzetto, Christian-Albrechts-Universität zu Kiel, Arbeitsbereich Analysis

For two Banach spaces $X,Y$ let $u:\mathbb{R}_{\geq 0}\rightarrow \mathcal{L}(X;Y)$ be an operator valued function and $\mathtt{P}$ a regularity property. Assume that each orbit $t\mapsto u(t)x$ has the regularity property $\mathtt{P}$ on some interval $(t_x,\infty)$ in general depending on $x\in X$. In this paper we prove a Baire-type theorem, which allows to remove the dependency of $x$ in certain situations. Afterwards, we provide some applications which are of interest in semigroup theory. In particular, we generalize and explain the result obtained by Bárta in his article \emph{Two notes on eventually differentiable families of operators}'' (Comment. Math. Univ. Carolin. 51,1 (2010), 19-24).
17.01.19 14:00 Am Schwarzenberg-Campus 3 (E), Raum 3.074 RBF Approximation with hierarchical matrices
Vincent Griem

In this presentation we will talk about the application of hierarchical matrices to solve the least squares problem arising in the RBF Approximation of scattered data.

We will shortly introduce hierarchical matrices as well as some central aspects of the RBF approach to scattered data. The main part will be about different ideas regarding the QR decomposition of hierarchical matrices.
18.12.18 15:00 H0.05 Predicting Stock Prices Based on Press Release Sentiment: A Comparison of Naïve Bayes Classifiers and Support Vector Machines [Masterarbeitsvortrag]
Max Lübbering
18.12.18 11:30 Am Schwarzenberg-Campus 3 (E), Raum 3.074 Knochendetektion in Röntgenbildern mittels Deep Learning [Forschungsprojektarbeit]
Stefan Dübel
13.12.18 14:00 Am Schwarzenberg-Campus 3 (E), Raum 3.074 Solving PDEs by the RBF-FD approach
Willi Leinen

I will present an introduction of the RBF-FD method and properties of the arising linear systems.
06.12.18 14:00 Am Schwarzenberg-Campus 3 (E), Raum 3.074 Challenges for drift-diffusion simulations of semiconductors: A comparative study of different discretization philosophies*
Dirk Peschka, Weierstraß-Institut, Berlin

In this talk we present results of a comparative study, where we analyze and benchmark the error and the convergence order of finite difference, finite-element as well as Voronoi finite-volume discretization schemes for the drift-diffusion equations describing charge transport in bulk semiconductor devices, i.e., the van Roosbroeck system.

The relation between the quasi-Fermi levels and the densities of electrons and holes is given by the equation of state. Three common challenges, that can corrupt the precision of numerical solutions of the van Roosbroeck system, will be discussed: boundary layers of the quasi-Fermi potentials at Ohmic contacts, discontinuties in the doping profile, and corner singularities in L-shaped domains. The influence on the order of convergence is assessed for each computational challenge and the different discretization schemes. Additionally, we provide an analysis of the inner boundary layer asymptotics near Ohmic contacts to support our observations.

* Vortrag im Rahmen des Kolloquiums für Angewandte Mathematik