Vorträge
Vorträge 1 bis 663 von 663  Seitenweise Ansicht 
Datum  Zeit  Ort  Vortrag 

18.12.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Towards a multigrid transformer model for highresolution spatial (climate) data* Max Witte, Deutsches Klimarechenzentrum Transformers have been a major breakthrough in Natural Language Processing (NLP) due to their ability to capture longrange dependencies through selfattention. However, the (self)attention mechanism suffers from massive memory consumption, especially for tasks with large context windows and high resolution data, such as climate data. Zoomlink: 
30.10.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Parallelintime methods for atmosphere simulation using time diagonalisation* Colin Cotter, Imperial College London The goal of parallelintime methods is to employ parallelism in the time direction in addition to the space direction, in the hope of obtaining further parallel speedups at the limits of what is possible due to spatial parallelism with domain decomposition alone. Recently diagonalisation techniques have emerged as a way of solving the coupled system for the solution of a differential equation at several timesteps simultaneously. One approach, sometimes referred to as “ParaDiag II” involves preconditioning this “allatonce” system obtained from time discretisation of a linear constant coefficient ODE (perhaps obtained as the space discretisation of a time dependent PDE) with a nearby system that can be diagonalised in time, allowing the solution of independent blocks in parallel. For nonlinear PDEs this approach can form the basis of a preconditioner within a NewtonKrylov method for the allatonce system after time averaging the (now generally time dependent) Jacobian system. After some preliminary description of the ParaDiag II approach, I will present results from our investigation of ParaDiag II applied to some testcases from the hierarchy of models used in the development of dry dynamical cores for atmosphere models, including performance benchmarks. Using these results I will identify the key challenges in obtaining further speedups and identify some directions to address these. Zoomlink: 
23.10.24  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Effizientes Lernen von Mischungen zweier Gaußscher Verteilungen (Bachelorarbeit) Rinor Balaj 
16.10.24  14:00  Zoom 
A Particle Tracking Framework for HighFidelity Trajectory Extraction* Erdi Kara, Spelman College We present a deep learningbased object tracking framework designed to accurately extract particle trajectories in diverse experimental settings. This framework, which leverages the stateoftheart object detection model YOLO and the Hungarian Algorithm, is particularly effective for scenarios where objects remain within the scene without coalescence. Our simple approach, requiring minimal initial human input, enables efficient, fast, and accurate extraction of observables of interest across various experimental configurations. The result is highfidelity data ideally suited for datadriven modeling applications.. Zoomlink: 
17.09.24  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Polynomial decay of semigroups Mark Veraar, TU Delft In this talk I will present some recent results on polynomial decay rates for C0semigroups, assuming that the resolvent grows polynomially at infinity in the complex right halfplane. Unlike many of the recent developments in the literature our results do not require the semigroup to be uniformly bounded. The talk is based on joint work with Chenxi Deng and Jan Rozendaal. 
17.09.24  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Randbedingungen für PhysicsInformed Neural Operators Niklas Göschel 
04.09.24  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Faktorisierung von Projektionsverfahren [Bachelorarbeit] Thorge Seefeld 
04.09.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Multidimensional function space summationbyparts operators with application to radial basis functions* Joshua Lampert Entropy stability is the foundation of numerical methods for hyperbolic conservation laws, thereby ensuring the stability and reliability of the resulting numerical solutions. Summationbyparts (SBP) operators provide a general framework to systematically develop entropystable schemes by mimicking continuous properties on a discrete level. They have proven to be a powerful tool to provide stable and highorder accurate numerical solutions. Classically, they are developed in order to differentiate polynomials up to a certain degree exactly. However, in many cases alternative function spaces are more appropriate to approximate the underlying solution space. Especially in multidimensional problems with potentially complex domains radial basis functions are known to possess very good approximation properties. The theory of radial basis function approximation provides us with stability and convergence results for scattered data approximation in a meshfree setting. Zoomlink: 
29.07.24  11:00  3D.aero, Billhorner Deich 96, 20539 Hamburg 
Automated EdgeSealing Inspection using Sparse StereoVision [Forschungsprojektarbeit] RazvanAndrei Draghici 
23.07.24  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Statistical Analysis of Racing Data [Bachelorarbeit] Wassim Alkhalil 
12.07.24  09:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Surrogate Models for Wing Flap Deformation Based on SINDy with Control Parameter [Bachelorarbeit] Nils Haufe 
10.07.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
ZeroShot SuperResolution with Neural Operators [Bachelorarbeit] Melanie Gruschka 
04.07.24  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Large components of random graphs Matthias Lienau Inhomogeneous random graphs are a prominent tool for modeling realworld complex networks as they manage to capture key concepts such as the scalefree property. In this talk we will focus on two particular inhomogeneous random graph models, the NorrosReittu model and the random connection model. The NorrosReittu model uses a deterministic vertex set and can be seen as a generalisation of the famous Erdős–Rényi graph. The random connection model on the other hand yields a spatial random graph, which leads to natural clustering effects. Our main goal is to determine the asymptotic behaviour of the size of the largest component as the number of vertices or the size of the observation window, respectively, goes to infinity. For the NorrosReittu model we also study asymptotics of other counting statistics. 
04.07.24  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Lower variance bounds and normal approximation of Poisson functionals with applications to stochastic geometry Vanessa Trapp Lower bounds for variances are often needed to derive central limit theorems. In this talk, a generalised reverse Poincaré inequality is established, which provides a lower variance bound for Poisson functionals that depends on the difference operator of some fixed order. 
02.07.24  16:15  Geomatikum, Besstraße 55, 20146 Hamburg, Hörsaal H5 
Random vertex detection and the size of typical cells Mathias Sonnleitner, Universität Münster 
19.06.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Towards Hybrid SpaceTime Finite Element/Deep Neural Network Methods Nils Margenberg Accurate flow simulations remain a challenging task. In this talk we discuss the use of deep neural networks for augmenting classical finite element simulations in fluiddynamics. Zoomlink: 
17.06.24  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Applications of Gaussian Processes in Machine Learning [Bachelorarbeit] Konstantin Zörner 
07.06.24  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Eine PythonC++ Kopplung für die Dyssol Software für Prozesssimulationen Sarra Daknou 
05.06.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Smaller Stencil Preconditioners for RBFFD discretized problems Michael Koch Radial basis function finite difference (RBFFD) discretization has recently emerged as an al Zoomlink: 
22.05.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Numerical solution of singularly perturbed differential equations using Haar wavelet* Vamika Rathi I will be introducing myself formally and presenting my master's thesis, which concerns the study of numerical schemes for solving singularly perturbed differential equations, focusing on the Haar wavelet method. Zoomlink: 
08.05.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Ethics in Computational Mathematics Prof. Max Kiener, Institute for Ethics in Technology This talk focuses on the mathematical models underlying reinforcement learning in artificial intelligence, particularly the reward functions in Markov Decision Processes. I argue that ethical principles related to wellbeing, safety, and equality are inherently reflected in these mathematical models. Building on this foundation, I then demonstrate how ethics can inform computational mathematics, while also addressing the challenges one encounters in this domain. Specifically, I discuss how the mathematical models behind reinforcement learning may rely on a distorted representation of ethics with respect to the determinacy and commensurability of ethical values. Zoomlink: 
30.04.24  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Multilevel Solvers for Radial Basis Function Finite Difference Discretized Differential Equations (Bachelorarbeit) Lasse Rippa 
03.04.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Applying SDC methods to the nextgeneration of weather forecasting models* Alex Brown, Met Office UK In Numerical Weather Prediction and Climate modelling, computational efficiency and numerical accuracy are paramount. This work aims to implement timeparallel Spectral Deferred Correction (SDC) methods in LFRicAtmosphere, the Met Office’s nextgeneration atmospheric model, designed to exploit the new supercomputers with improved scalability; the use of a quasiuniform cubedsphere mesh is integral to this, as is the underlying lowestorder compatible finite element spatial discretisation. LFRicAtmosphere has an iterative semiimplicit time stepping structure with a Method of Lines finitetransport scheme using an explicit RungeKutta time discretisation. Time parallel SDC offers increased temporal accuracy with small computation cost, this could be utilised over the whole time discretisation, or to target a specific time discretised component. Zoomlink: 
22.03.24  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Masterarbeit: Parameteridentifizierung mit Methoden des Maschinellen Lernens Sahra Naser 
06.03.24  12:00  Am SchwarzenbergCampus 3, Raum H03 und Zoom 
Efficient numerical methods for the MaxeyRiley equations with Basset history term Julio Urizarna The MaxeyRiley Equation (MRE) models the motion of a finitesized, spherical particle moving in a fluid. Applications using the MRE are, for example, the study of the spread of Coronavirus particles in a room, the formation of clouds and the socalled marine snow. The MRE is a secondorder, implicit integrodifferential equation with a singular kernel at initial time. For over 35 years, researchers used approximations and numerical schemes with high storage requirements or ignored the integral term, although its impact can be relevant. A major breakthrough was reached in 2019, when Prasath et al. mapped the MRE to a timedependent Robintype boundary condition of the 1D Heat equation, thus removing the requirement to store the full history. They provided an implicit integral form of the solution by using the socalled Fokas method that could be later solved with a numerical scheme and a nonlinear solver. While Prasath et al.’s method can deliver numerical solutions accurately, the need to evaluate nested integrals makes it computationally costly and it becomes impractical for computing trajectories of a large number of particles. In this talk, we present a new fourth order finite differences scheme and compare its accuracy and performance with Prasath et al’s method as well as other existing schemes. We then apply our method for the calculation of Lagrangian Coherent Structures, a large scale fluid structure, and point out for which cases, the approximations on the MRE have a considerable influence on these structures and the use of the full MRE models is relevant. Zoomlink: 
27.02.24  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Hawkes processes and their scaling limits for asset pricing models [Bachelorarbeit] Niklas Jona Lohmann 
23.02.24  09:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Surrogatmodelle für Lastsimulationen von Flügelklappen Ana Vidya Moreno Molina 
14.02.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Training Large Language Models on HighPerformance Computing Systems Chelsea John, Forschungszentrum Jülich This presentation explores the intricacies of training large language models (LLM) on HighPerformance Computing (HPC) systems, unveiling the key components, challenges, and optimizations involved in handling the computational demands of stateoftheart language models. Delving into the nuances of model architecture, data preprocessing, and hyperparameter tuning, a comprehensive understanding of parallelization strategies, scalability challenges, and resource allocation will be given. Additionally, the talk touches on the implications for research, highlighting potential progress and future applications of LLMs. Zoomlink: 
02.02.24  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Dimension estimation [Studienarbeit] Michel Krispin 
24.01.24  13:00  TUHH, Am SchwarzenbergCampus 3 (E), Raum 3.074 
Sampling Theorems in Positive Definite Reproducing Kernel Hilbert Spaces [Bachelorarbeit] Lennart Ohlsen, Studiengang TM, Betreuer und Erstprüfer: Armin Iske 
24.01.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Lowsynchronization techniques for communication reduction in Krylov subspace methods* Kathryn Lund, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg With exascalecapable supercomputers already on the horizon, reducing communication operations in orthogonalization kernels like QR factorization has become even more imperative. Lowsynchronization GramSchmidt methods, first introduced in Swirydowicz et al. (Numer. Lin. Alg. Appl. 28(2):e2343, 2020), have been shown to improve the scalability of the Arnoldi method in highperformance, distributed computing. Block versions of lowsynchronization GramSchmidt show further potential for speeding up algorithms, as columnbatching allows for maximizing cache usage with matrixmatrix operations. We will examine how lowsynchronization block GramSchmidt variants can be transformed into block Arnoldi variants for use in standard Krylov subspace methods like block generalized minimal residual methods (BGMRES). We also demonstrate how an adaptive restarting heuristic can handle instabilities that arise with the increasing condition number of the Krylov basis. The performance, accuracy, and stability of these methods are assessed via a flexible comparison tool written in MATLAB. Zoomlink: 
15.01.24  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Development of a Conversational Interface Based on InstitutionSpecific Documentation through LLM Finetuning [Projektarbeit] Philip Suskin Zoomlink: 
10.01.24  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
A scalar inverse problem with Neural Galerkin Scheme* Djahou Norbert Tognon, Sorbonne Universite Neural networks trained with machine learning techniques are currently attracting great attention as nonlinear approximation methods to solve forward and inverse problems involving highdimensional partial differential equations (PDEs). In a recent paper, Neural Galerkin scheme has been proposed to solve PDEs by means of deep learning. In this approach, the deep learning process generates the training data samples with an active learning process for the numerical approximation. We apply this approach in this talk to tackle a parameter estimation problem and propose an algorithm based on Neural Galerkin scheme to estimate a scalar coefficient involved in a nonlinear PDE problem. We provide numerical results with Kortewegde Vries (KdV) equation in one dimension. Zoomlink: 
09.01.24  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
DataDriven Approaches for the MaxeyRiley Equation [Masterarbeit] Niklas Dieckow 
08.01.24  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Approximation methods in sequence spaces Riko Ukena, E10, Am SchwarzenbergCampus 3 (E), Raum 3.074 We discuss approximation methods for linear equations in sequence spaces. When cutting out a finite matrix from an infinite dimensional operator, a choice of boundary conditions has to be made. Choosing zero boundary conditions leads to the classical finite section method, for which conditions for the applicability are known. We derive similar conditions for the applicability for the choice of periodic boundary conditions. 
21.12.23  17:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Kürzeste Pfadlänge in KNearestNeighborGraphen [Bachelorarbeit] Ali Maznouk 
20.12.23  17:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Gaussian upper heat kernel bounds on graphs Christian Rose, Universität Potsdam tba 
20.12.23  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Almost everywhere convergence for noncommutative spaces Christian Budde, University of the Free State, Bloemfontein, Südafrika Almost everywhere convergence is an essential part of classical measure theory. However, when passing to the quantum setting of noncommutative spaces, the absence of an explicit measure space makes it very difficult to give expression to notions like almost everywhere convergence. There is a rich literature devoted to different ways of circumventing this challenge, positing various notions of “measure theoretic” convergence in the noncommutative case. However, not many of these seem to be suited to dealing with Haagerup spaces. In this talk we review several noncommutative notions of convergence before proposing versions of these notions which have been recast in terms of spectral projections. The harmony of exisiting notions with these revised notions is then investigated in the semifinite setting, at which point we also demonstrate the efficacy of the “new” approach by establishing a matching noncommutative monotone convergence theorem. On the basis of the theory achieved in the semifinite setting, we then show how this “reshaped” theory may be lifted to the setting of Haagerup spaces. In closing we show that even here a monotone convergence theorem based on these notions is valid. This is joint work with L. Labuschagne and C. Steyn. 
20.12.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Approximation of Evolution Equations with Random Data Katharina Klioba, Technische Universität Hamburg Evolution equations are a class of partial differential equations arising frequently in physical applications, such as heat or wave equations. To account for unknown material parameters or measurement inaccuracies, they can be considered with random coefficients or a noise term. However, analytical solutions are often out of reach and a numerical solution is required. Several questions arise regarding the influence of the random terms on the discretisation. In this talk, I will give an overview of convergence rates that can be obtained in the random setting. 
07.12.23  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Time Optimal Control in Reflexive Banach Spaces Johannes Stojanow Time optimal controllability of abstract differential equations refers to reaching a desired target state within a minimal transition time. Further imposing a bound on control functions representing the energy available for control leads to the interesting BangBang property, i.e. the timeoptimal control function attains full norm on the transition time interval. Building upon investigations in Fattorini (SIAM J. Control Ser. A, 2(1): 5459, 1964) and later Wang & Zhang (SIAM J. Control Optim., 55(3): 18621886, 2017), we generalize results on existence, BangBang property and uniqueness of time optimal controls to reflexive Banach spaces. An example in heat diffusion will illuminate the relation of the BangBang property with observability inequalities. Zoomlink: 
06.12.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Solving Nonlinear Finite Element Problems in Elasticity* Lina Fesefeldt Finite element methods (FEM) for displacement problems in elasticity lead to systems of nonlinear equations. These equations are usually solved with Newton's method or a related method. Based on a benchmark problem in highorder FEM, we explore traditional solution techniques for the nonlinear equation system such as step width selection and QuasiNewton methods. We also consider algorithms specifically designed for displacement problems in nonlinear structural analysis like load step and arclength methods. We extend traditional load step methods to a new approach exploiting the hierarchical structure of the problem and saving about 50% of computation time (vs. benchmark). In an outlook, we discuss new developments in nonlinear preconditioning and their applicability to displacement problems in nonlinear FEM. Zoomlink: 
20.11.23  16:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Compound Poisson approximation of Ustatistics in stochastic geometry Bernhard Hafer, Universität Osnabrück 
15.11.23  14:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Inequalities between Neumann and Dirichlet Laplacian eigenvalues on planar domains Jonathan Rohleder, Stockholms universitet We generalize a classical inequality between the eigenvalues of the Laplacians with Neumann and Dirichlet boundary conditions on bounded, planar domains: in 1955, Payne proved that below the kth eigenvalue of the Dirichlet Laplacian there exist at least k+2 eigenvalues of the Neumann Laplacian, provided the domain is convex. It has, however, been conjectured that this should hold for any domain. Here we show that the statement indeed remains true for all simply connected planar Lipschitz domains. The proof relies on a novel variational principle. 
13.11.23  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Normalizing Flows for Linear Inverse Problems Paul Büchler 
08.11.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
ParallelInTime Integration with Applications to Real World Problems from Electrical Engineering* Prof. Sebastian Schöps, TUDarmstadt Timedomain simulation of largescale problems becomes computationally prohibitive if spaceparallelization saturates. This is particularly challenging if long time periods are considered, e.g., if the startup of an electrical machine until steady state is simulated. In this contribution, several parallelintime methods are discussed for initialboundaryvalue problems and for timeperiodic boundary value problems. All those methods are based on a subdivision of the time interval into as many subintervals as computing cores are available. For example, the wellknown parareal method works similarly to multiple shooting methods; it solves two types of problems iteratively until convergence is reached: a cheap problem defined on coarse grids is solved sequentially on the whole timeinterval to propagate initial conditions (and approximate derivatives) and secondly, highfidelity problems are solved on the subintervals in parallel. We also discuss Paraexp and Waveform Relaxation methods in the context of real world engineering problems from electrical engineering. Zoomlink: 
02.11.23  16:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
BA Verteidigung: Strukturen mit wenig Farbwechseln in gefärbten Netzwerken Carina Möller 
01.11.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Physics Informed Neural Networks for the Lorentz Equations* Finn Sommer Physics Informed Neural Networks (PINNs) are becoming increasingly important in solving initial and boundary value problems. In contrast to conventional neural networks, they do not require labelled data for training and can thus be assigned to the field of unsupervised learning [3]. In this work, a PINN is to be trained to learn the equation of motion of a charged particle in an electromagnetic field. It turns out that networks trained using the LBFGS opimisation algorithm show better convergence behaviour than those trained using the Adam optimisation algorithm commonly used in deep learning. In addition, it turns out that pretraining neural networks on the solution of a numerical method such as the CrankNicolson method can significantly speed up the training of PINNS. Zoomlink: 
26.10.23  13:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
BA Verteidigung: Hamiltonkreise in Subgraphen des Hyperwürfels Janne Hackbart 
25.10.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Parareal with a physics informed neural network as coarse propagator* Abdul Qadir Ibrahim Parallelintime algorithms provide an additional layer of concurrency for the numerical integration of models based on timedependent differential equations. Methods like Parareal, which parallelize across multiple time steps, rely on a computationally cheap and coarse integrator to propagate information forward in time, while a parallelizable expensive fine propagator provides accuracy. Typically, the coarse method is a numerical integrator using lower resolution, reduced order or a simplified model. Our reasearch proposes to use a physicsinformed neural network (PINN) instead. We demonstrate for the BlackScholes equation, a partial differential equation from computational finance, that Parareal with a PINN coarse propagator provides better speedup than a numerical coarse propagator. Training and evaluating a neural network are both tasks whose computing patterns are well suited for GPUs. By contrast, meshbased algorithms with their low computational intensity struggle to perform well. We show that moving the coarse propagator PINN to a GPU while running the numerical fine propagator on the CPU further improves Parareal's singlenode performance. This suggests that integrating machine learning techniques into parallelintime integration methods and exploiting their differences in computing patterns might offer a way to better utilize heterogeneous architectures. Zoomlink: 
17.10.23  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Ein auf maschinellem Lernen basierter Ansatz für "nudging" für "superresolution" Benjamin Riedemann 
10.10.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
PhysicsConstrained Deep Learning for Downscaling and Emulation* Paula Harder, Fraunhofer ITWM The availability of reliable, highresolution climate and weather data is important to inform longterm decisions on climate adaptation and mitigation and to guide rapid responses to extreme events. Forecasting models are limited by computational costs and, therefore, often generate coarseresolution predictions. Two common ways to decrease computational efforts with DL are downscaling, the increase of the resolution directly on the predicted climate variables, and emulation, the replacement of model parts to achieve faster runs initially. Here, we look at several downscaling tasks and an aerosol emulation problem. While deep learning shows promising results it may not obey simple physical constraints, such as mass conservation or mass positivity. We tackle this by investigating both soft and hard constraining methodologies in different setups, showing that incorporating hard constraints can be beneficial for both downscaling and emulation problems. Zoomlink: 
05.10.23  11:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Initial and Boundary Values for Evolutionary Equations Andreas Buchinger, Institut für Angewandte Analysis, TU Bergakademie Feriberg The theory of evolutionary equations, afforded by Rainer Picard (Dresden) et al., provides a wellposedness theorem applicable to a vast amount of linear PDEs including heat, wave and Maxwell's equations as well as equations including fractional derivatives and integrals. In this talk, I will discuss this wellposedness theorem in the autonomous case. I will show how to impose initial and boundary conditions on such evolutionary equations, and I will present a possible evolutionary approach to control theory for PDEs. 
27.09.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Harnessing the Power of GPUs: A Path to Efficiency and Excellence* Prof. Sohan Lal, Massively Parallel Systems Group Graphics Processing Units (GPUs), initially designed as accelerators for graphics applications, have revolutionized the computing landscape with their unparalleled computational prowess. Today, GPUaccelerated systems are present everywhere – for example, in our smartphones, cars, and supercomputers. GPUaccelerated systems are transforming the world in many ways, and several exciting possibilities, such as digital twins and precision medicine are on the horizon. While GPUaccelerated systems are desirable, their optimal utilization is crucial; otherwise, they can be very expensive in terms of power and energy consumption, which is not good as we aspire to reduce our carbon footprint. A single GPU can draw up to 700 watts, while GPUpowered supercomputers scale to the energyhungry range of 1 to 10 megawatts. Zoomlink: 
19.09.23  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: SuperResolution für die Flachwassergleichungen Larissa Schaumburg 
14.09.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Spectra of aperiodic Schrödinger operators [Masterarbeit] Yasmeen Mai Hack, JMIM 
14.09.23  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Niveaumengen der Resolventennorm [Bachelorarbeit] Daniel Wolf, TM 
28.08.23  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Erkennen von Botnetzen in Netzwerken [Bachelorarbeit] Constantin Witt 
11.08.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Mondrian forests for classification [Bachelorarbeit] Mohamed Yassine Daghfous 
09.08.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Random polytopes in polytopes Matthias Reitzner, Universität Osnabrück 
25.07.23  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Upper bound on Parareal with spatialcoarsening* Ausra Pogozelskyte, University of Geneva Parareal is the most studied ParallelinTime method; by introducing parallelism in the time dimension, it allows to relieve communication bottlenecks that appear when parallelism is used only in the spatial dimension. Zoomlink: 
12.07.23  16:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Erkennung von Clustern in zufälligen Graphen mit Hilfe von Dichten von Teilgraphen [Bachelorarbeit] Antonia Gustke 
10.07.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
DirichletEigenwerte des zufälligen $q$ZuständePartikels [Bachelorarbeit] Mattes Wittig, TM 
07.07.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Extraktion strukturierter Daten aus deutschen Personalausweisen [Projektarbeit] Anton Majboroda 
05.07.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Efficient and robust numerical methods based on adaptivity and structure preservation* Prof. Hendrik Ranocha, AM – Angewandte Mathematik, Universität Hamburg We present some recent developments for the numerical simulation of 
26.06.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Directed random geometric graphs [Bachelorarbeit] Nour Abdennebi 
21.06.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
On the MicroMacro Parareal Algorithm Applied to FESOM2 Benedict Philippi We applied the ParallelInTime algorithm Parareal to the oceancirculation model FESOM2 to demonstrate its applicability to complex problems in climate research. The talk is intended to give an overview of the technical challenges that can be expected when attempting to parallelize stateoftheart simulation software in time. With the convergence results presented the talk concludes with a discussion of whether and how an efficient application of Parareal could be achieved. 
20.06.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Vergleich verschiedener Verfahren der Dimensionsreduktion [Projektarbeit] Tom Ahlgrimm 
16.06.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Algorithmen für die Burning Number von Zufallsgraphen [Bachelorarbeit] Jan Lucian Haßinger 
14.06.23  13:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Numerical Treatment of Laplacian Edge Sharpening [Bachelorarbeit] Phan Hoang Minh Nguyen, Studiengang TM 
12.06.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Ein alternativer Ansatz zu bilateralen Filtern [Masterarbeit] Michael Koch, Studiengang TM 
08.06.23  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Concentration of measure via moment inequalities Holger Sambale, RuhrUniversität Bochum We study the interplay between moment and tail inequalities in the concentration of measure phenomenon. A motivating example are socalled higher order concentration bounds, where functions are addressed which have unbounded first order derivatives (or differences) but whose derivatives of some higher order are bounded. A variety of different situations is considered like (classical) Euclidean spaces, discrete situations, functions of independent random variables and the Poisson space. A special emphasis is put on pointing out the parallels and common ground throughout all these cases. 
07.06.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Machine Learning the Trajectories of the MaxeyRiley Equation Leon Schlegel Since we now have implemented an efficient solver for the MaxeyRiley equation, we can generate a lot of trajectory data. This data could be used to train a neural network, which can predict the trajectories given a starting postion. Because the dynamics are governed by an integrodifferential equation, the future path of a trajectory depends on the whole past. This characteristic could be handled using recurrent neural networks. 
24.05.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Challenges and Opportunities in Medical Image Reconstruction Tobias Knopp Tomographic imaging is an essential tool in medical diagnostics, allowing diseases to be detected much earlier 
17.05.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Hierarchical Block Structures for the Preconditioning of Saddle Point Problems with HMatrix Decompositions Jonas Grams Fluid flow problems can be modelled by the NavierStokes, or Oseen equations. Their discretization results in saddle point problems. These systems of equations are typically very large and need to be solved iteratively. Standard (block) preconditioning techniques for saddle point problems rely on an approximation of the Schur complement. Such an approximation can be obtained by a hierarchical matrix (HMatrix) LUdecomposition for which the Schur complement is computed explicitly. The computational complexity of this computation depends, among other things, on the hierarchical block structure of the involved matrices. However, widely used techniques do not consider the connection between the discretization grids for the velocity field and the pressure, respectively. Thus, a problem dependent hierarchical block structure for the FEM discretization of the gradient operator is presented. The block structure of the corresponding saddle point matrix block is improved by considering the connection between the two involved grids.Numerical results will show that the improved block structure allows for a faster computation of the Schur complement, the bottleneck for the setup of the HMatrix LUdecomposition. 
10.05.23  13:15  Am SchwarzenbergCampus 4 (D), Raum 1.025 
Extension of Linear Functions Onto Multivectors Using Geometric Algebra [Bachelorarbeit] Alexander Busch 
10.05.23  12:00  D 1.025 
A mathematical introduction to quantum computing Professor Martin Kliesch, Institute for QuantumInspired and Quantum Optimization The first part of the presentation provides an introduction to quantum mechanics and quantum algorithms. In the second part, I will present an overview of the research at the new TUHH institute on the topic (see www.tuhh.de/quantum) and explain the mathematical aspects of it. 
02.05.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Image Registration with Flownet [Masterarbeit] Raghuram Satish 
26.04.23  12:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
A lowrank correction for relaxed Schur complement preconditioners Rebekka Beddig The numerical solution of saddlepoint systems arising in computational fluid dynamics with iterative solvers 
19.04.23  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: OneClass Support Vector Machines Viet Hung Vu 
18.04.23  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Image Inpainting with Partial Convolutions Lukas Mührke 
17.04.23  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Discretetime TASEP with holdback Vsevolod Shneer, HeriotWatt University, Edinburgh 
29.03.23  13:00  Am SchwarzenbergCampus 1 (A), Raum A1.19 
Flächeninterpolation und Punktoptimierung bei NCDaten (Bachelorarbeit) Leon Greve 
01.03.23  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Normal Approximation of Poisson Functionals via Generalized $p$Poincaré Inequalities Tara Trauthwein, Universität Luxemburg In this talk, we present new explicit bounds on the Gaussian approximation of Poisson functionals, based on novel estimates of moments of Skorohod integrals. Combining these with the MalliavinStein method, we derived bounds in the Wasserstein and Kolmogorov distances whose application requires minimal moment assumptions on addone cost operators — thereby extending the results from (Last, Peccati and Schulte, 2016). Our main application is a CLT for the Online Nearest Neighbour graph, whose validity was conjectured in (Wade, 2009; Penrose and Wade, 2009). We also applied our techniques to derive quantitative CLTs for edge functionals of the Gilbert graph, of the kNearest Neighbour graph and of the Radial Spanning Tree, both in cases where qualitative CLTs are known and unknown. 
21.02.23  13:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Digital Annealing for the Vehicle Routing Problem with Occasional Drivers Jan Niklas Diercks 
14.02.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Lights Out auf zufälligen Graphen [Bachelorarbeit] Ghislain Nkamdjin Njike 
30.01.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Glimpse into Classical and Modern Control Theory Johannes Stojanow This talk will be devoted to several topics in classical and modern control theory. Classical stabilization techniques for linear and nonlinear control systems as well as modern attempts to linearize nonlinear systems will constitute the core for this presentation. In particular, the first part will consist of a brief summary of my Master's Thesis on the foundations of mathematical control theory in finite dimension. During the second part, we will catch a glimpse into modern control theory involving the Koopman operator focussing on advances and difficulties. The third part will be on my current PhD topic "TimeOptimal Control of Linear Systems in NonReflexive Banach Spaces". The official introduction to my person will also not come too short. 
24.01.23  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Zufälliges Suchen in Graphen mit Hilfe von Sternen Sören Grünhagen 
23.01.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Machine learning for weather and climate modelling* Peter Düben, European Centre for MediumRange Weather Forecasts This talk will start with a highlevel overview on how machine learning can be used to improve weather and climate predictions. Afterwards, the talk will provide more detail on recent developments of machine learned weather forecast models and how they compare to conventional models and numerical methods. 
23.01.23  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Sensorfusion mit einer bewegten Kamera [Masterarbeit] Johannes Bostelmann 
19.01.23  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Relations between variants of stochastic gradient descent and stochastic differential equations [Masterarbeit] Jonathan Hellwig 
19.12.22  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Masterarbeit: Datenkompression zur Reduzierung des Speicherbedarfs von zeitparallelen Algorithmen Ole Räthcke 
14.12.22  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.091 
Fouriertransformation und Anwendungen in der Signalverarbeitung [Bachelorarbeit] Katharina Buchholz 
14.12.22  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.046 
Bachelorarbeit: Bild und Videosegmentierung mittels maschinellem Lernen Monir Taeb Sharifi 
12.12.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 & Zoom 
Numerical homogenization of dispersive Maxwell systems* Philip Freese, Institut für Mathematik, Universität Augsburg We study the propagation of electromagnetic waves in heterogeneous structures. The governing equations for this problem are Maxwell's equations with highly oscillatory parameters. We use an analytic homogenization result, which yields an effective Maxwell system that involves additional dispersive effects. 
05.12.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Error Analysis in Time of Stochastic Evolution Equations Katharina Klioba We consider stochastic PDEs driven by an additive or multiplicative Gaussian noise of the form 
28.11.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 & Zoom 
Introductory talk Sophie Externbrink In my introductory talk I will introduce myself and present the results of my master thesis. 
23.11.22  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.047 
Masterarbeit: Development of Optimized Artificial Neural Networks for the Characterization of Wake Vortex Parameters Lars Stietz 
21.11.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 + Zoom 
Lower bounds for variances of Poisson functionals Vanessa Trapp Lower bounds for variances are often needed to derive central limit theorems. In this talk, we establish a specific lower bound for the variance of a Poisson functional that uses the difference operator of Malliavin calculus. 
14.11.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 + Zoom 
Exploiting the Flexibility of Spectral Deferred Correction Methods* Martin Weiser, ZIB Spectral Deferred Correction (SDC) methods are iterative solvers for collocation discretization of ordinary differential equations, but each iterate can also be interpreted as particular RungeKutta (RK) scheme. In contrast to fixed RK schemes, viewing SDC as a fixed point iteration allows combining them with various kinds of deliberate perturbations resulting from mesh adaptivity or algebraic adaptivity in PDEs, lossy compression in parallelintime solvers, or inexact computations in scaleseparated long time integrations, for improved performance. It also fosters a deeper understanding of SDC approximation error behavior, and the construction of more efficient preconditioners. In the talk, we will touch several of these aspects, and provide a  necessarily incomplete  overview of the astonishing flexibility of SDC methods. 
14.11.22  14:00  Am SchwarzenbergCampus 2 (B), Raum B0.001 
Mündlich Prüfung zur Dissertation: On Observability Estimates for Semigroups in Banach Spaces Dennis Gallaun 
11.11.22  11:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Ein PotenzSchurkomplement Präkonditionierer mit Niedrigrangkorrektur für schwachbesetzte lineare Gleichungssysteme (Bachelorarbeit) David Sattler 
11.11.22  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Pressurerobustness in the context of optimal control* Winnifried Wollner, Universität Hamburg The talk discusses the benefits of pressurerobust discretizations in the scope of optimal control of incompressible flows. 
07.11.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 + Zoom 
On augmenting spectral methods by normalizing flows  Schrödinger equation as an example Yahya Saleh Approximating functions by a linear span of truncated basis sets is a standard procedure for the numerical solution of differential equations. Commonly used concepts of approximation methods are wellposed and convergent, by provable approximation orders. On the down side, however, these methods often suffer from the curse of dimensionality, which limits their approximation behavior. Nonlinear approximation methods, such as neural networks, were shown to be very efficient approximating highdimensional functions. We investigate nonlinear approximation methods that are constructed by composing standard basis sets with normalizing flows. Such models yield richer approximation spaces while maintaining the density properties of the initial basis set, as we show. We investigate such approximation schemes for solving molecular Schrödinger equations and provide linear and nonlinear convergence analysis. 
26.10.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Optimierung der ParityCheckMatrizen von LDPCCodes [Masterarbeit] Jannik Jacobsen 
26.10.22  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Positionsbestimmung von SeefrachtContainern anhand von 3DLiDAR Daten [Bachelorarbeit] Martin Pham, Studiengang CS, mit SICKAG 
25.10.22  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Evaluation of Machine Learning Methods for the Identification of Planar Surfaces [Masterarbeit] Vikram Sachdeva 
24.10.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Modelling of stochastic gradient descent with stochastic differential equations Jonathan Hellwig Stochastic optimization techniques have become an essential tool for training of 
14.10.22  15:00  Zoom (link below) or in Room A  1.16 
On Spectral Theory, Control, and Higher Regularity of Infinitedimensional Operator Equations Fabian Gabel Describing aspects of physical phenomena by forming abstract mathematical models is a common practice in scientific work: the mathematical formalism allows for permeation of the mathematical model as a means of creating insights and knowledge over the described realworld phenomenon. 
10.10.22  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Masterarbeit: TwoComponent Model for Tracer Simulation Sophie Externbrink 
05.10.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Implizitexplizite Zeitschrittverfahren für die MaxeyRiley Gleichungen Leon Schlegel 
22.09.22  11:00  in Zoom 
Entwicklung einer dezentralen Geschwindigkeitsplanung auf einem autonomen LeaderFahrzeug für ein sensorloses Intralogistikfahrzeug [Bachelorarbeit] Selina Meier, Studiengang TM 
12.09.22  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Ultrakleine skalenfreie geometrische Netzwerke (Bachelorarbeit) Nikolaus Rehberg 
18.08.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Zentrale Grenzwertsätze im Random Connection Model Franz Nestmann, Karlsruher Institut für Technologie (KIT), Fakultät für Mathematik, Institut für Stochastik 
29.07.22  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Refinement of Jet simulations usingGenerative Adversarial Networks [Masterarbeit] Shruthi Janardhan At the Large Hadron Collider, the interaction of subatomic particles with matter lead to severalmillions of collisions every second. For each collision, upto thousands of particles are producedfollowing stochastic processes. The accurate description of these particles require thousands ofvariables, which leads to large data sets with high dimensionality. The interaction of particleswith the detectors (like Compact Muon Solenoid) are best simulated with the GEANT4 software.Alternatively, less precise but faster simulations are sometimes preferred to reach higher statisticalprecision. We present recent progresses of refinement of fast simulations with Machine Learningtechniques to enhance the quality of such fast simulations. We demonstrate the use of adversarialnetworks in the context of jet simulation using the Wasserstein distance metric. The architectureconsists of opposing networks, Refiner and Critic. A Refiner refines the distribution of the energyof the jets obtained with the fast simulation. The Critic is used to effectively differentiate betweenthe distributions of refined energy and the distribution obtained by the GEANT4 simulation. Weapply the technique to jet kinematics, when the response is close to Gaussian, first on toy data setsand then on realistic data sets 
14.07.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Skeleta and shapes related to random tessellations Daniel Hug, Karlsruher Institut für Technologie (KIT), Fakultät für Mathematik, Institut für Stochastik 
11.07.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Spectral inequalities and observability with sensor sets of decaying density Albrecht Seelmann, TU Dortmund, Fakultät für Mathematik We discuss spectral inequalities and observability for the harmonic oscillator and more general Schrödinger operators with confinement potentials on the whole space. It turns out that the (super)exponential decay of the corresponding eigenfunctions allows to consider sensor sets with a density that exhibits a certain decay. This, in particular, permits sensors with finite measure. 
07.07.22  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 & Zoom 
Asymptoticpreserving and hybrid finitevolume/MonteCarlo methods for kinetic equations in the plasma edge of a fusion reactor* Giovanni Samaey, KU Leuven Nuclear fusion reactor design crucially depends on numerical simulation. The plasma can usually be modeled using fluid equations (for mass, momentum and energy). However, the reactor also contains neutral (noncharged) particles (which are important in its operation), of which both the position and velocity distribution is important. This leads to a Boltzmanntype transport equation that needs to be discretised with a Monte Carlo method. In highcollisional regimes, the Monte Carlo simulation describing the evolution of neutral particles becomes prohibitively expensive, because each individual collision needs to be tracked. 
07.07.22  10:30  Big Blue Button 
Objektivierung des Fahrkomforts automatisierter Fahrzeuge [Masterarbeit] Nele Thomsen 
04.07.22  11:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Gaussian Kernel Ridge Regression using Matrix Decompositions for Preconditioning (Bachelorarbeit) Ons Gharbia 
01.07.22  09:00  TUHH, Raum B0.001 und in Zoom 
WARTESCHLANGENTHEORIE IN ROBOTISIERTEN LAGERHALTUNGSSYSTEMEN [Habilitationskolloquium] Karsten Kruse Aufgrund des zunehmenden Wachstums im ECommerceSektor haben robotisierte Lagerhaltungs 
27.06.22  15:00  Zoom 
Recent investigations on spectral sets and Crouzeix’s conjecture Felix Schwenninger, via Zoom We discuss recent developments around approaches to Crouzeix's conjecture, the statement that the numerical range is a 2 spectral set for any complex square matrix. This includes spectral constants for specific classes of operators. 
20.06.22  15:00  Zoom 
An efficient numerical method for the MaxeyRiley equation Julio Urizarna Carasa The MaxeyRiley Equation (MRE) models the motion of a finitesized, spherical particle moving in a fluid. Applications using the MRE are, for example, the study of the spread of Coronavirus particles in a room, the formation of clouds and the socalled marine snow. The MRE is a secondorder, implicit integrodifferential equation with a singular kernel at initial time. For over 35 years, researchers used approximations and numerical schemes with high storage requirements or ignored the integral term, although its impact can be relevant. A major breakthrough was reached in 2019, when Prasath et al. mapped the MRE to a timedependent Robintype boundary condition of the 1D Heat equation, thus removing the requirement to store the full history. They provided an implicit integral form of the solution by using the socalled Fokas method that could be later solved with numerical scheme and a nonlinear solver. While Prasath et al.’s method can deliver numerical solutions of very high accuracy, the need to evaluate nested integrals makes it computationally costly and it becomes impractical for computing trajectories of a large number of particles. In the talk, we will present a finite differences approach that it is not only storage efficient but also much faster. We will compare our approach to both Prasath et al.’s method as well as a to the numerical schemes developed by A. Daitche in 2013 for direct integration of the original MaxeyRiley equation with integral term. 
16.06.22  15:00  Online 
Solving the traveling salesman problem via deep reinforcement learning [Masterarbeit] Darius Schaub 
10.06.22  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Planung und Optimierung von Schnittpfaden für dynamisch begrenzte Kinematiken bzgl. Ausschussreduktion [Masterarbeit] Constantin Riß 
30.05.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Spectral deferred correction methods for secondorder problems Ikrom Akramov Spectral deferred corrections (SDC) is an iterative method for the numerical solution of ordinary differential equations. It can be interpreted as a Picard iteration for the collocation problem, preconditioned with a low order method. SDC has been studied for first order problems, using explicit, implicit or implicitexplicit Euler as preconditioner. It has been shown that SDC can achieve arbitrary high order of accuracy and possesses good stability properties. 
23.05.22  15:00  Zoom 
On observability estimates for semigroups in Banach spaces Dennis Gallaun In this talk, I would like to present the main results of my PhD thesis. 
09.05.22  15:00  Zoom 
Resilience in Spectral Deferred Corrections Thomas Baumann, FZ Jülich Advancement in computational speed is nowadays gained by using more processing units rather than faster ones. 
02.05.22  15:00  Zoom 
Robot manipulation in realtime, in the realworld, and under uncertainty.* Wisdom Agboh, University of Leeds Robots have the potential to disrupt many aspects of our lives, from healthcare to manufacturing. To realize this potential, a key challenge is realtime robot manipulation. Given a task, how can a robot quickly generate a motion plan to successfully complete it? How can the robot react in realtime to potential uncertainties in the realworld as it executes its plan? In this talk, we will overview recent developments at the University of Leeds, to realize realtime robot manipulation. These will include parallelintime integration methods that leverage parallel computing to significantly speedup physics predictions for various robot manipulation tasks. It will also include learningbased and optimal controlbased methods for robots to handle realworld uncertainties in object pose estimation and model parameters. We hope these recent advances will help accelerate the next generation of intelligent robots. 
25.04.22  15:00  Zoom 
Component sizes of scalefree inhomogeneous random graphs Matthias Lienau The NorrosReittu model is an inhomogeneous random multigraph that exhibits the socalled scalefree or powerlaw behaviour, which is observed in realworld complex networks. We study the component sizes of the NorrosReittu model in the subcritical regime, i.e. in the abscence of a giant component, and show convergence of the point process of the component sizes to a Poisson process. It is planned to derive similar results for other models such as the random connection model. 
11.04.22  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 & Zoom 
Introductory Talk: Boundary layer enriched Hybrid Discontinuous Galerkin Methods for Convection dominated flow Abdul Qadir Ibrahim The thesis deals with boundary layer enrichment of convection dominated flow problems using the Hybrid Discontinuous Galerkin Method. It aims to introduce an appropriate and computationally efficient Hybrid Discontinuous Galerkin formulation for the most important model problems of incompressible fluid flow, namely the convectiondiffusion equation.The main contribution is the derivation, discussion and analysis of the Enriched Finite elementSpace using nonpolynomial spaces (specifically boundary layer functions) for both the Discontinuous Galerkin Methods and the Hybrid Discontinuous Galerkin Method. We evaluate the robustness (i.e linear stability as well as reasonable linear systems) and accuracy of this method using various analytical and realistic problems and compare the results to those obtained using the standard (H)DG method. Numerical results are provided to contrast the Enriched (H)DG methods with standard (H)DG approaches. 
31.03.22  16:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Understanding Double Descent in Neural Networks [Bachelorarbeit] Marvin Steinmeister 
29.03.22  10:00  Zoom 
Random Walks and Tridiagonal Matrices [Masterarbeit] Luis Weber, TM 
23.02.22  10:30  Zoom 
Untersuchung statistischer Vorhersagealgorithmen für Offshore WetterZeitreihen [Bachelorarbeit] Sebastian Eberle 
22.02.22  15:00  Online 
Forecasting the shipped volume using a neural network model based on a booking data driven pickup approach [Masterarbeit] Gordon Lisch 
15.02.22  13:00  online 
Machine Learning of Gradientbased Optimization Methods [Bachelorarbeit] Leonard Schröter 
14.02.22  15:00  Online 
Training MobileNetV2 on ImageNet with different activation functions [Projektarbeit] Abdul Bostan 
09.02.22  12:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Uniform Turán density Samuel Mohr In the early 1980s, Erd\H{o}s and S\'os initiated the study of the classical Tur\'an problem with a uniformity condition: the uniform Tur\'an density of a hypergraph $H$ is the infimum over all $d$ for which any sufficiently large hypergraph with the property that all its linearsize subhyperghraphs have density at least $d$ contains $H$. In particular, they raise the questions of determining the uniform Tur\'an densities of $K_4^{(3)}$ and $K_4^{(3)}$. The former question was solved only recently in [Israel J. Math. 211 (2016), 349366] and [J. Eur. Math. Soc. 20 (2018), 11391159], while the latter still remains open for almost 40 years. 
07.02.22  15:00  Zoom 
Observability for the (anisotropic) Hermite semigroup from finite volume or decaying sensor sets* Ivan Veselic, TU Dortmund, Fakultät für Mathematik, Lehrstuhl LSIX We study the observability and null control problem for 
04.02.22  13:30  Zoom (same as coffee chat) 
Second Order Information in Neural Network Training Lina Fesefeldt Since I am new to our institute, I will start by introducing myself and presenting the results of my master thesis on second order information in 
28.01.22  13:30  Zoom 
Discontinuous Galerkin Spectral Element Methods  SpaceTime Formulations and Efficient Solvers Lea Miko Versbach We are interested in constructing cheap and efficient implicit high order 
27.01.22  13:00  Zoom 
Reinforcement Learning von Parametern für RungeKutta Methode [Bachelorarbeit] Finn Sommer https://tuhh.zoom.us/j/82516486683?pwd=RnV4ZEcvREhXeDYyZXdiUE1kUmh1QT09 
25.01.22  17:00  Zoom 
Schleifen und Mehrfachkanten im Konfigurationsmodell [Bachelorarbeit] Happy Khairunnisa Sariyanto 
24.01.22  15:00  zoom 
A new approach to the hot spots conjecture Dr. Jonathan Rohleder, Stockholm University, Sweden It is a conjecture going back to J. Rauch (1974) that the hottest and coldest spots in an insulated homogeneous medium such as an insulated plate of metal should converge to the boundary, for "most" initial heat distributions, as time tends to infinity. This socalled hot spots conjecture can be phrased alternatively as follows: the eigenfunction(s) corresponding to the first nonzero eigenvalue of the Neumann Laplacian on a Euclidean domain should take its maximum and minimum on the boundary only. This has been proven to be false for certain domains with holes, but it was shown to hold for several classes of simply connected or convex planar domains. One of the most recent advances is the proof for all triangles given by Judge and Mondal (Annals of Math. 2020). The conjecture remains open in general for simply connected or at least convex domains. In this talk we provide a new approach to the conjecture. It is based on a nonstandard variational principle for the eigenvalues of the Neumann and Dirichlet Laplacians. 
17.01.22  15:00  Zoom 
Solution of the vibrational Schrödinger equation using neural networks [Masterarbeit] Jannik Eggers 
07.01.22  13:30  zoom 
Behavior of Nonlinear Water Waves in the Presence of Random Wind Forcing Leo Dostal Specific solutions of the nonlinear Schrödinger equation, such as the Peregrine breather, are considered to be prototypes of extreme or freak waves in the oceans. An important question is whether these solutions also exist in the presence of gusty wind. Using the method of multiple scales, a nonlinear Schrödinger equation is obtained for the case of windforced weakly nonlinear deep water waves. Thereby, the wind forcing is modeled as a stochastic process. This leads to a stochastic nonlinear Schrödinger equation, which is calculated for different wind regimes. For the case of wind forcing which is either random in time or random in space, it is shown that breathertype solutions such as the Peregrine breather occur even in strong gusty wind conditions. 
06.01.22  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bachelorarbeit: Taskbasierte Implementierung von Parareal mittels torcpy Florentine Meerjanssen, Institut für Mathematik 
17.12.21  13:30  Zoom 
LowRank Updates for Schur Complement Preconditioners Rebekka Beddig Atmospheric dynamics can be described by the Boussinesq approximation which models bouyancydriven fluid flows. Its simulation involves the repeated solution of the NavierStokes equations. This requires numerical solution methods for the dense Schur complement. In this talk, we will be concerned with Schur complement preconditioners. Furthermore, we will discuss a lowrank update for the Schur complement preconditioners. The update method is based on the error between the preconditioned Schur complement and the identity. It will be illustrated with some numerical results. 
10.12.21  13:30  Zoom 
A Block Householder Based Algorithm for the QR Decomposition of Hierarchical Matrices Vincent Griem Hierarchical Matrices are dense but datasparse matrices that use lowrank factorisations of suitable submatrices to allow for storage with linearpolylogarithmic complexity. Furthermore, efficient approximations of matrix operations like matrixvector and matrixmatrix multiplication, matrix inversion and LU decomposition are available. There are several approaches for the computation of QR factorisations in the hierarchical matrix format, however, they suffer from numerical drawbacks that limit their use in many applications. In this talk, I will present a new approach based on block Householder transformations that improves upon some of those problems. To prevent unnecessary high ranks in the resulting factors and increase speed as well as accuracy the algorithm meticulously tracks for which intermediate results lowrank factorisations are available. 
30.11.21  17:15  Online via Zoom 
Statistische Analyse von Fehlern in Schachpartien [Bachelorarbeit] Paul Roth 
29.11.21  15:00  Online & E3.074 (talk via zoom) 
Local pressurecorrection for flow problems Malte Braack, ChristianAlbrechtsUniversität zu Kiel We present a novel local pressure correction method for incompressible fluid flows. Pressure correction methods 
22.11.21  15:00  E3.074 & zoom (talk via zoom) 
A Hybrid Approach for Databased Models Using a Leastsquares Regression* Malin Lachmann An increased use of renewable energy could significantly contribute to decelerate climate change but cannot be realized easily since most renewable energy sources underlie volatile availability. Using of storage devices and scheduling consumers to times when energy is available can increase the amount of renewable energy that is used. For this purpose, adequate models that forecast the energy generation and consumption as well as the behavior of storage devices are essential. We present a computationally efficient modeling approach based on a leastsquares problem that is extended by a hybrid model approach based on kmeans clustering and evaluate it on realworld data at the examples of modeling the state of charge of a battery storage and the temperature inside a milk cooling tank. The experiments indicate that the hybrid approach leads to better forecasting results, especially if the devices show a more complicated behavior. Furthermore, we investigate whether the behavior of the models is qualitatively realistic and find that the battery model fulfills this requirement and is thus suitable for the application in a smart energy management system. Even though forecasts for the hybrid milk cooling model have low error values, further steps need to be taken to avoid undesired effects when using this model in such a sophisticated system. 
19.11.21  13:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 + Zoom 
Shearletbased Approach to Dynamic Computed Tomography Thorben Abel I will introduce myself and present the topic of my master thesis. 
11.11.21  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Informationen zweiter Ordnung im Training neuronaler Netze [Masterarbeit] Eva Lina Fesefeldt 
08.11.21  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 & Zoom 
How Stein met Malliavin in Paris and what happened next: nonlinear approximation, limit theorems, chaos and the first four moments Simon Campese Back in 2009, both Stein's method  a probabilistic technique to derive quantitative limit theorems  and Malliavin calculus  a stochastic version of the calculus of variations  had already established themselves as standard tools in their respective domain, even though both were discovered quite recently in 1972 and 1978, respectively. Then they started an innocent liaison in Paris which quickly developed into a very strong bond (despite numerous affairs), leading to fame and success both in and outside the probabilistic community. This bond is today known as the MalliavinStein approach. 
08.11.21  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Physicsinformed neural networks for reconstructing flow velocity fields [Bachelorarbeit] Michel Krispin 
05.11.21  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 + Zoom 
Coupling Methods in Probability Theory Hermann Thorisson, Department of Mathematics, University of Iceland Coupling means the joint construction of two or more random variables, processes, or any random objects. The aim of the construction could be to deduce properties of the individual objects, or to gain insight into distributional relations between them, or to simulate a particular object. It has been called The Probabilistic Method since it is not based on methods from other fields of mathematics. 
01.11.21  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Approximating Evolution Equations with Random Coefficients Katharina Klioba Solving evolution equations with random coefficients numerically requires discretizing in space, time and of random parameters. As numerical methods for all three discretisations are wellknown, it is natural to ask under which conditions they can be combined. In this talk, we discuss this question with a special emphasis on preservation of strong convergence rates. 
25.10.21  15:00  Raum 3.074 & Zoom (same link as coffee chat) 
A Parareal Algorithm for Shallow Water Equations Judith Angel The trend towards massively parallel highperformance computers requires the development of parallel algorithms to employ their computational power. 
21.10.21  15:00  Zoom (see below for link) 
The quest for the cortical algorithm* Dr. Helmut Linde, Merck KGaA, Darmstadt, Germany How will the next generation of Artificial Intelligence (AI) look like? Comparing today's AI algorithms with biological intelligence, one of the most remarkable differences is the ability of the human brain to somehow understand the 'essence' of things: A small child can easily identify any type of object after having seen only a few examples or recognize a song even when played on different instruments or in a different key. In other words: Brains are able to create abstract concepts of realworld entities  and today's algorithms are not. 
21.10.21  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 und Zoom 
Nonautonomous DeschSchappacher perturbations Christian Budde, NorthWest University, Potchefstroom, South Africa For many processes in sciences, the coefficients of the partial differential equation describing a dynamical system as well as the boundary conditions of it may vary with time. In such cases one speaks of nonautonomous (or timevarying) evolution equations. From an operator theoretical point of view one considers families of Banach space operators which depend on the time parameter and studies the associated nonautonomous abstract Cauchy problem. We consider timedependent DeschSchappacher perturbations of nonautonomous abstract Cauchy problems and apply our result to nonautonomous uniformly strongly elliptic differential operators on Lp spaces. This is joint work with Christian Seifert (TUHH). 
18.10.21  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 & Zoom 
Methods in Quantum Optimal Transport Dennis Schmeckpeper I will introduce myself and present the topic of my master thesis. 
30.09.21  16:00  TUHH, Gebäude D, 1.021 und Zoom 
MakerBreaker Spiele über mehrere Runden [Bachelorarbeit TM] Juri Barkey 
30.09.21  15:00  Zoom 
Varianten von ToucherIsolator Spielen auf Graphen [Bachelorarbeit TM] Leon Speidel 
30.09.21  14:00  Zoom 
Über die ErdösHajnalVermutung [Bachelorarbeit TM] Luis Fernando Fernandez Salvador 
30.09.21  11:00  Online 
Trainierbare Aktivierungsfunktionen in neuronalen Netzen [Projektarbeit] Firaz Khokhar 
24.09.21  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 and via Zoom 
Boundedness and Compactness of Toeplitz+Hankel Operators Raffael Hagger, University of Reading / ChristianAlbrechtsUniversität zu Kiel Suppose that $A$ is a bounded linear operator on the Hardy space $H^p$ that satisfies 
21.09.21  11:00  Zoom (Zugangsdaten im Einladungstext) 
New Combinatorial Proofs for Enumeration Problems and Random Anchored Structures Alexander Haupt Hallo liebe Institutsmitarbeiter*innen, 
21.09.21  10:00  Zoom (URL kommt per Email) 
Der QuarterLaplace als schneller Filter zur kantenerhaltenden Glättung in Bildern Leif Jensen, [Bachelorarbeit TM] 
19.08.21  14:00  Zoom 
Preferential Placement  ein neuer Ansatz für zufällige Graphen (Bachelorarbeit) Nils Koch 
16.08.21  15:00  Zoom 
Anwendungsbezogene automatisierte Optimierung von Parametern einer digitalen Industriekamera [Masterarbeit] Jonas Eckhoff 
16.08.21  14:00  Zoom 
Bilaterale Filter [Masterarbeit] Thanh Hung Le 
26.07.21  13:00  Zoom 
Gesichterkennung und Tensorenfaktorisierung (Bachelorarbeit) Moritz Pirk 
23.07.21  11:00  Zoom & Am SchwarzenbergCampus 3 (E), Raum 3.074 
Modifizierte BlockGramSchmidt Orthogonalisierung (Bachelorarbeit) Finn Heck 
20.07.21  10:00  Zoom 
Numerical Methods for the Rotating Shallow Water Equations with Bathymetry (Bachelor Arbeit) Joshua Lampert 
12.07.21  15:00  zoom 
L^{p}extrapolation of nonlocal operators Patrick Tolksdorf, Institut für Mathematik an der Johannes GutenbergUniversität Mainz In this talk, we discuss nonlocal operators like elliptic integrodifferential operators of fractional type 
05.07.21  15:00  Zoom (same as Coffee Chat) 
Integral inputtostate stability of unbounded bilinear control systems René Hosfeld We study integral inputtostate stability of bilinear systems with 
28.06.21  15:00  Zoom 
Some peculiar (and not very well known) aspects of Gauss quadrature rules* Thibaut Lunet, Université de Genève Gauss quadrature rules are nowadays not only a powerful tool to compute integrals in many scientific applications, but also a numerical method that most people in the scientific community at least heard of at some point in there life. 
21.06.21  15:00  Zoom 
Can Spectral Deferred Correction methods improve Numerical Weather Prediction? Joscha Fregin Atmospheric motion covers a broad range of time and spatial scales. Low and high pressure systems can influence us for days or even weeks and they extend up to hundreds of kilometers. In contrast, sound waves pass by in seconds with wavelengths of centimeters to meters. Implicitexplicit (IMEX) time stepping methods can help to avoid drastic limitations on the time step induced by the variety of scales without requiring computationally expensive fully nonlinear implicit solves. I will introduce Spectral Deferred Correction (SDC) methods as a strong competitor to currently used schemes. They allow an easy construction of high order schemes in contrast to e.g IMEX RungeKutta methods which require a growing number of coupling conditions with increasing order. 
14.06.21  15:00  Zoom (Same as Coffee Chat) 
(A)periodic Schrödinger Operators Riko Ukena Discrete Schrödinger operators are used to describe systems in theoretical solidstate physics. 
11.06.21  15:00  Zoom (same as Coffee Chat) 
On convergence rates of forminduced semigroup approximation Katharina Klioba Solving evolution equations numerically requires discretizing both in time and in space. However, these two problems can be treated seperately. A common approach to spatial discretization relies on solving the weak formulation on finitedimensional subspaces. On a semigroup level, this corresponds to approximating a semigroup by semigroups on finitedimensional subspaces. For practical applications, quantifying the convergence speed is essential. This can be achieved by the quantified version of the TrotterKato theorem presented in this talk. Rates of strong convergence are obtained on dense subspaces under a joint condition on properties of both the form and the approximating spaces. An outlook to evolution equations with random coefficients and their polynomial chaos approximation will be given as well as a generalization allowing to treat the DirichlettoNeumann operator. 
10.06.21  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Algorithmische Ansätze für kürzeste Wege mit wenigen Farbwechseln im Hyperwürfel (Bachelorarbeit) Tim Meyer Zoom Link folgt. 
31.05.21  15:00  Zoom(Same as Coffee Chat) 
Preconditioning of saddle point problems Jonas Grams In many problems, like the discretized Stokes or NavierStokes equation, linear systems of saddle point type arise. Since the condition number for such problems can grow unbounded, as the number of unknowns grows, good preconditioners are key for solving such problems fast. 
26.05.21  15:00  Zoom 
Coupling Conditions for the BGK Equation and Associated Macroscopic Equations on Networks. Ikrom Akramov In this talk, we examine linearized kinetic BGK equation in 1D velocity dimension. It is closely related to the MaxwellBoltzmann equation for gas dynamics. The equation that we are interested is obtained by linearization of the equation around Maxwellian. We discuss the kinetic and macroscopic equations and the boundary and coupling conditions for this equation. 
17.05.21  15:00  Zoom: 
Image reconstruction from scattered Radon data by weighted kernel functions Kristof Albrecht Positive definite kernel functions are powerful tools, which can be used to solve a variety of mathematical problems. One possible application of kernelbased methods is the reconstruction of images from scattered Radon data, which is described in [1]. More precisely, the authors introduced weighted kernel functions to solve the reconstruction problem via generalized interpolation. Although the reconstruction method was quite competitive in comparison to standard Fourierbased methods, a detailed discussion on wellposedness and stability was mainly missing. 
05.05.21  15:00  BBB 
Training of YOLO with altered activation function [Bachelorarbeitsvortrag] Minh An Pham 
03.05.21  15:00  Zoom 
Hypothesis tests in regression models with longrange dependence Matthias Lienau, Institute of Mathematics, Chair of Stochastics In my inaugural talk I would like to introduce myself and present the topic of my master thesis. To this end, I will first provide a brief introduction to empirical processes and longrange dependence. Afterwards, we consider the problem of testing the equality of two nonparametric regression functions. Finally, we provide a goodness of fit test for the error distribution. 
26.04.21  15:00  Zoom 
Inertial Particles in a viscous fluid: The MaxeyRiley equation. Julio Urizarna The characterisation of the dynamics of a small inertial particle in a viscous fluid is a problem that dates to Stokes[1], back in 1851. Since his first attempt, many have tried and several formulas have been obtained for different types of flows, as well 
12.04.21  15:00  Zoom 
Malliavin calculus and MalliavinStein method Vanessa Trapp In this talk, I would like to introduce myself and the topic of my master thesis "Malliavin calculus and MalliavinStein method". 
30.03.21  13:00  BBB 
Banachs HyperebenenProblem (Bachelorarbeitsvortrag) Max Levermann 
16.03.21  16:00  Online 
Einfluss von BatchNormalisierung für verschiedene Aktivierungsfunktionen [Bachelorarbeitsvortrag] Moritz Seefeldt 
16.03.21  15:00  Online 
Relation between Activation Function and Weight Initialization in Neural Networks [Bachelorarbeitsvortrag] Erich Doclaf 
15.03.21  15:00  Zoom meeting 
A semiimplicit meshfree/particle scheme for the shallow water equations* Dr. Adeleke Bankole, Institute of Mathematics, Hamburg University This presentation introduces the semiimplicit Smoothed Particle Hydrodynamics (SPH) 
25.02.21  09:00  BBB 
Mündliche Prüfung zur Dissertation: Fractional Powers of Linear Operators in Locally Convex Vector Spaces Jan Meichsner 
24.02.21  14:00  Online 
Neuronale Netzwerke mit (approximativ) orthonormalen Gewichtsmatrizen [Bachelorarbeitsvortrag] Marco Zabel 
18.02.21  13:00  Zoom 
Habilitationskolloquium: „Polynomial Chaos Expansion“ Christian Seifert MeetingID: 820 3979 6993 
15.02.21  15:00  Zoom, Link per Mail 
Verified solution of ODEs by Taylor models implemented in MATLAB/INTLAB Dr Florian Bünger, Institute for Reliable Computing Solving differential equations rigorously is a main and vigorous topic in the 
11.02.21  15:00  Online 
Domänentransfer von Gesichtsbildern aus Passdokumenten mit Generative Adversarial Networks [Projektarbeitsvortrag] Dominic Hinz 
25.01.21  15:00  Zoom 
The Kortewegde Vries equation on graphs Christian Seifert 
12.01.21  09:00  Online (Zoom). Zugangsdaten in der Einladung. 
"New Algorithms for BlockStructured Integer Programming: Theory and Practice" (Bachelorarbeit) Vanessa Oetjen, E10 / E11 (Prof. Mnich) https://tuhh.zoom.us/j/87535538628?pwd=RTJ0ZGp0ZWc1NVk3RGp5NTBQYjhVdz09 
11.01.21  15:00  Zoom 
Stabilization of Control Systems in Banach Spaces Dennis Gallaun 
04.01.21  15:00  Zoom 
Something with ... wait for it ... networks and robots* Sonja Otten Production processes are usually investigated using models and methods from queueing theory (queue = line where people wait for goods or services). Control of warehouses and their optimization rely on models and methods from inventory theory. Both theories are fields of Operations Research, but they comprise quite different methodologies and techniques. In classical Operations Research these theories are considered as disjoint research areas. Today's emergence of complex supply chains (=productioninventory networks) calls for integrated productioninventory models, which are focus of my research. We have developed Markov process models for several productioninventory systems and derived the steady state distribution of the global system. For most of the productioninventory systems the obtained steady state is of product form. This enables us to analyse the long term average costs with the aim to find the optimal inventory size. 
07.12.20  15:00  Zoom 
Vectorvalued holomorphic functions in several variables Karsten Kruse 
30.11.20  15:00  Zoom 
rcross tintersecting families via necessary intersection points Yannick Mogge 
23.11.20  15:00  Zoom 
About myself, my master thesis and current/future research Judith Angel An overview about the master thesis will be given, treating numerical methods for solving a PDEconstrained optimization problem. Afterwards, an outlook on advanced numerical methods for PDEs and modelling of tsunamis will be presented. 
16.11.20  16:15  Online (Zoom Link folgt) 
"Geodesics with few colour changes in the hypercube" (Bachelorarbeit) Branko Schaub 
16.11.20  15:00  Zoom 
From Stein's Method to Stochastic Geometry Matthias Schulte Stein's method is a powerful technique to establish convergence in distribution of a sequence of random variables to a standard Gaussian random variable. After an introduction to this approach, its application to several problems from stochastic geometry is discussed. 
13.10.20  16:00  Zoom 
Overview on Axon and Myelin Segmentation of Microscopy Data Using Convolutional Neural Networks [Forschungsprojektarbeit] Ruhullah Najafi 
23.09.20  10:00  Zoom 
Verbesserung eines Segmentieralgorithmus für flache Fingerabdrücke auf Basis einer vergleichenden Analyse [Bachelorarbeit] Thomas Plotz 
11.09.20  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 / OnlineStream 
Rationale Aktivierungsfunktionen in neuronalen Netzen (Bachelorarbeitsvortrag) Fabian Bahr 
10.09.20  15:30  (Zoom Link wird am 09.09. per EMail angekündigt) 
Bildsegmentierung durch Deep Learning mit UNet und dem MumfordShahFunktional [Bachelorarbeit] Jannik Jacobsen 
26.08.20  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074/75 
Fast Strategies for WaiterClient and ClientWaiter Games [Bachelorarbeit] Sophie Externbrink, E10 
24.08.20  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 / OnlineStream 
Neuronale Netze basierend auf RadialeBasisFunktionen (Bachelorarbeitsvortrag) Marcel Franz 
10.08.20  15:30  Zoom 
On the Axioms of Quantum Mechanics Dennis Schmeckpeper This will be an introductory talk on how the fundamental assumptions of quantum mechanics are modeled and how this relies on the spectral theory of unbounded selfadjoint operators on separable Hilbert spaces. 
03.08.20  15:30  Zoom 
$\mathcal{H}_2 \otimes \mathcal{L}_\infty$Optimal Model Order Reduction Rebekka Beddig I will introduce myself and present the topic of my master thesis. 
27.07.20  15:00  Zoom 
Timeparallel flow estimation Sebastian Götschel Deformable image registration is a key technology in medical imaging; there the goal is to compute a meaningful spatial correspondence between two or more images of the same scene. One approach is to use an optimal control formulation to compute a stationary velocity field that parameterize the deformation map. The same methods can be used to estimate the motion of contrast agents from 3d ultrasound images. 
23.07.20  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
PDEConstrained Optimization of Parabolic Problems [Masterarbeit] Judith Angel 
21.07.20  16:00  Zoom Vortrag (Zoom Link wird am 21.07. per EMail angekündigt) 
Geometric Deep Learning in Medical Image Segmentation and Comparisons with UNET (Masterarbeit) Björn Przybyla 
20.07.20  15:30  Zoom 
Noncommutative geometry, Ktheory and other interesting stuff Julian Großmann An overview talk about interesting topics in mathematical physics I used over the last years. It should be accessible for a broader audience. 
13.07.20  15:30  Zoom 
Evolution Equations Christian Seifert This will be an overview talk on Evolution Equations (and a bit on Evolutionary Equations). 
06.07.20  15:30  Zoom 
Uniqueness of solutions to the CaffarelliSilvestre Problem Jan Meichsner We consider the CaffarelliSilvestre problem in a Banach space $X$ which is finding a solution $u$ to the problem 
29.06.20  15:00  Zoom 
A new approach to the QR decomposition of hierarchical matrices Vincent Griem All existing QR decompositions for hierarchical matrices suffer from numerical drawbacks that limit their use in many applications. In this talk, I will present a new method based on the recursive WYbased QR decomposition by Elmroth and Gustavson. It is an extension of an already existing method for a subclass of hierarchical methods developed by Kressner and Susnjara. 
22.06.20  15:30  Zoom 
Analysis of the discretization error in the RBFFD method Willi Leinen Partial differential equations can be solved numerically by the radial basis functiongenerated finite difference (RBFFD) method, which can be viewed as a generalization of the finite difference method to unstructured point sets. 
15.06.20  15:30  Zoom 
Approximate nullcontrollability of heatlike equations in $L_1(\mathbb{R}^d)$ Dennis Gallaun 
25.05.20  15:30  Zoom 
On periodic Finite Sections Riko Ukena, E10 I will introduce myself and talk about my master thesis. 
18.05.20  15:30  Zoom 
ManyBody Localization: A Spectral Theoretic Investigation of Spin Chains Katharina Klioba, E10 Since most of you couldn't attend my master thesis defense due to the university closure, I would like to use this talk to present you some results of my master thesis "Manybody localization: A spectral theoretic investigation of spin chains". Spin chains are a class of quantummechanical models wellsuited to study manybody localization (MBL) phenomena due to their onedimensional structure. After a brief introduction to oneparticle (Anderson) localization and spectral properties of infinitedimensional operators, we will see possible definitions and manifestations of MBL. The proofs of MBL for two specific spin chains will be sketched, illustrating how oneparticle and manybody techniques can be combined. Furthermore, I would like to use this talk to properly present myself in case you wondered who that person in the guest office was. 
11.05.20  15:30  Zoom 
$\mathcal{H}$Matrix Approximation of Finite Element Problems Jonas Grams Since I am new to the institute, I want to use this talk to introduce myself to you, and talk a little bit about my master thesis. 
06.05.20  10:00  Online 
Development of SolidState LIDAR Configuration Tool and Optimization of SPAD Detection Performance [Master thesis] Puja Dutta, student of Microelectronics and Microsystems Engineering supervision by Prof. Ernst Brinkmeyer (retired 2013, hence not hosted by him) 
05.05.20  10:00  Videokonferenz 
Numerical Treatment of Hyperbolic Equations [Bachelorarbeit] Triani Nur Zahra 
04.05.20  15:30  Online 
On the observability of nonautonomous systems Fabian Gabel 
27.04.20  15:30  Online 
Lattice Index of Coupled Cell Networks Haibo Ruan For a regular coupled cell network, we define an index of integer tuples for its associated lattice of synchrony subspaces, and use this index for identifying equivalent synchrony subspaces to be merged to each other. Based on this equivalence, the initial lattice of synchrony subspaces can be reduced to a lattice of synchrony subspaces which corresponds to a simple eigenvalue case discussed in previous work. The result is a reduced lattice of synchrony subspaces, which affords a welldefined nonnegative integer index that can be used for bifurcation analysis in regular coupled cell networks. 
22.04.20  11:00  per Videokonferenz 
Error analysis of radial basis functions finite difference discretization (Bachelorarbeit) Paul Jürß 
20.04.20  15:30  Online 
SISDC for NWP, geometric constraints in Rossby wave interactions and a little about me Joscha Fregin After only two weeks of being able to get to know you in person, I will use this talk to introduce myself and talk about present and past work. My presentation will be divided into three parts. After shortly introducing myself (1), I'll cover the following topics related to my masters thesis (2) and my PhD research (3). 
16.04.20  11:00  VideoOnline 
Multiscale Hierarchical Convolutional Neural Networks  Implementations and Applications (Projekarbeit) Ernst Nathanael Winter 
07.04.20  10:00  per Videokonferenz (Zugangsdaten kommen per Email) 
Graphen und spektraltheoretische Interpretation des Bilateralen Filters [Bachelorarbeit TM] Lars Stietz 
06.04.20  15:30  Zoom 
Introduction to different functional calculi with applications Jan Meichsner, TUHH, Institut für Mathematik, Lehrstuhl für angewandte Analysis, TUHH, Institut für Mathematik (E10), Am SchwarzenbergCampus 3, Gebäude E, 21073 Hamburg The presentations aims to give a rather short nontechnical introduction in the general concept of a functional calculus including several examples and applications. 
24.03.20  14:00  per Videokonferenz 
Verbesserung der Ansteuerung von TimeofFlight Tiefenbildsensoren [Bachelorarbeit TM, Kooperation mit der Basler AG] Johannes Bostelmann 
24.03.20  11:00  per Videokonferenz 
Über periodisierte "finite sections" [Masterarbeit TM] Riko Ukena 
18.03.20  13:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
ManyBody Localization: A Spectral Theoretic Investigation of Spin Chains [Masterarbeit] Katharina Klioba 
28.02.20  10:00  TUHH, M 0.571 
Entwicklung, Modellierung und Simulation eines neuartigen, kostengunstigen und zuverlässigen Wellenenergiewandlers [Bachelorarbeit TM, gemeinsam mit Institut M13] Leonard Paul Schulz 
27.02.20  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
A short presentation about myself Don Julio Urizarna Carasa Quite often, we wonder about the people around us but we are too shy to actually ask. On Thursday 27.02.2020, the Institute für Mathematik has organised a presentation about the one that is – up to the current date and not for very long – its latest “outstanding” acquisition. 
20.02.20  13:15  Raum H  SBC5  H0.03 
Novel SpaceTime Finite Element Discretizations* Prof. Dr. Marek Behr, Chair for Computational Analysis of Technical Systems (CATS), RWTH Aachen University Movingboundary flow simulations are an important design and analysis tool in many areas, including civil and biomedical engineering, as well as production engineering. Interfacecapturing offers flexibility for complex freesurface motion, while interfacetracking is very attractive due to its mass conservation properties at low resolution. We focus on these alternatives in the context of flow simulations based on stabilized finite element discretizations of NavierStokes equations, including spacetime formulations that allow extra flexibility concerning grid design at the interface. 
19.02.20  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Comparison of Unsupervised Dimensionality Reduction Techniques (Bachelorarbeit) Lior Polak 
11.02.20  14:00  Am SchwarzenbergCampus 5 (H), Raum H0.02 
Solving nonlinear nonautonomous equations Hendrik Vogt, Fachbereich 3  Mathematik, Universität Bremen, Postfach 330 440, Bibliothekstraße 5, 28359 Bremen We show the existence of solutions of nonlinear nonautonomous Cauchy problems 
10.02.20  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Das Verhalten von IDRVerfahren unter Einfluss von Rundungsfehlern (Bachelorarbeit) Henning Schwarz 
30.01.20  14:00  Raum H  SBC5  H0.04 
Fractional derivatives and integrals as application of different functional calculi Jan Meichsner, Institut für Mathematik (E10), Lehrstuhl Angewandte Analysis The question of possible generalisations of the operation of differentiation towards fractional powers can be traced back to a letter from L'Hospital to Leibniz in 1695 ([1]). 
23.01.20  14:45  Eißendorfer Straße 40 (N), Raum 0007 
Einblicke in die Modellierung des Materialverhaltens von Elastomerwerkstoffen Nils Hendrik Kröger, Deutsches Institut für Kautschuktechnologie e.V., Hannover, Eupener Straße 33, 30519 Hannover, Deutschland Im Maschinen und Automobilbau werden für mechanisch extrem beanspruchte, temperatur und chemikalienbeständige Bauteile Elastomerwerkstoffe benötigt. Typische Beispiele sind Reifen, Zahn und Keilriemen, Motor und Aggregatelager, Luftfedern und Fahrwerkbuchsen sowie statisch und dynamisch beanspruchte Dichtungen. Die Anforderungen bezüglich Zuverlässigkeit und Leistungsdichte sind speziell in Verbindung mit den hochsensiblen, sicherheitsrelevanten Funktionen der Bauteile besonders hoch. 
16.01.20  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Greedy methods in kernel based approximation Kristof Albrecht Positive Kernels provide methods to solve multivariate interpolation problems, but standard kernel methods usually lead to illconditioned linear systems. Therefore, a suitable choice of interpolation centers and basis functions reqiures particular care. 
09.01.20  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
A tractable approach for 1bit compressed sensing on manifolds Sara KrauseSolberg, Institut für Mathematik (E10), Lehrstuhl Angewandte Analysis Compressed Sensing deals with reconstructing some unknown vector from few linear measurements in high dimension by additionally assuming sparsity, i.e. many entries are zero. Recent results guaranteed recovery even when just signs of the measurements are available (onebit CS). A natural generalization of classical CS replaces sparse vectors by vectors lying on manifolds having low intrinsic dimension. In this talk I introduce the onebit problem and proposes a tractable strategy to solve onebit CS problems for data lying on manifolds. This is based on joint work with Johannes Maly and Mark Iwen. 
19.12.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
ParallelinTime PDEconstrained Optimization* Dr. Sebastian Götschel, Zuse Institut Berlin (ZIB) Largescale optimization problems governed by partial differential equations (PDEs) occur in a multitude of applications, for example in inverse problems for nondestructive testing of materials and structures, or in individualized medicine. Algorithms for the numerical solution of such PDEconstrained optimization problems are computationally extremely demanding, as they require multiple PDE solves during the iterative optimization process. This is especially challenging for transient problems, where methods working on the reduced objective functional are often employed to avoid a full spatiotemporal discretization of the associated optimality system. The evaluation of the reduced gradient then requires one solve of the state equation forward in time, and one backwardintime solve of the adjoint equation. In order to tackle reallife applications, it is not only essential to devise efficient discretization schemes, but also to use advanced techniques to exploit computer architectures and decrease the timetosolution, which otherwise is prohibitively long. 
16.12.19  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Präkonditionierer für lineare Systeme aus RBFFD diskretisierten partiellen Differentialgleichungen (Bachelorarbeit) Henrik Wyschka 
12.12.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
MolecularContinuum Flow Simulation with MaMiCo: Where HPC and Data Analytics Meet Prof. Dr. Philipp Neumann, HelmutSchmidtUniversität Molecularcontinuum methods, as referred to in my talk, employ a domain decomposition and compute fluid flow either by means of molecular dynamics (MD) or computational fluid dynamics (CFD) in the subdomains. This enables multiscale investigations of nano and microflows beyond the limits of validity of classical CFD. 
05.12.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
A new approach to the QR decomposition of hierarchical matrices Vincent Griem All existing QR decompositions for hierarchical matrices suffer from numerical drawbacks that limit their use in many applications. In this talk, I will present a new method based on the recursive WYbased QR decomposition by Elmroth and Gustavson. It is an extension of an already existing method for a subclass of hierarchical methods developed by Kressner and Susnjara. 
26.11.19  17:00  Am SchwarzenbergCampus 5 (H), Raum H0.10 
Twoscale convergence for evolutionary equations Marcus Moppi Waurick, Department of Mathematics and Statistics, University of Strathclyde, Livingstone Tower, 26 Richmond Street, Glasgow G1 1XH, Scotland, Room number: LT1007 In the talk, we shall develop a general framework for the treatment of both deterministic and stochastic homogenisation problems for evolutionary equations. The versatility of the methods allow the unified treatment of static, dynamic as well as mixed type problems. 
21.11.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Parallelintime integration with PFASST: from prototyping to applications Robert Speck, Jülich Supercomputing Centre, Forschungszentrum Jülich GmbH, WilhelmJohnenStraße, 52428 Jülich The efficient use of modern supercomputers has become one of the key challenges in computational science. New mathematical concepts are needed to fully exploit massively parallel architectures. For the numerical solution of timedependent processes, timeparallel methods have opened new ways to overcome scaling limits. With the "parallel full approximation scheme in space and time" (PFASST), multiple timesteps can be integrated simultaneously. Based on spectral deferred corrections (SDC) methods and nonlinear multigrid ideas, PFASST uses a spacetime hierarchy with various coarsening strategies to maximize parallel efficiency. In numerous studies, this approach has been used on up to 448K cores and coupled to spaceparallel solvers with finite differences, spectral methods or even articles for discretization in space. Yet, since the integration of SDC or PFASST into an existing application code is not straightforward and the potential gain is typically uncertain, we will present in this talk our Python prototyping framework pySDC. It allows to rapidly test new ideas and to implement first toy problems more easily. We will also discuss the transition from pySDC to applicationspecific implementations and show recent use cases. 
18.11.19  14:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Das verbesserte Produkt Hierarchischer Matrizen durch Verwendung von erweiterten SummenAusdrücken (Masterarbeit) Max Gandyra 
14.11.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Where are my ions? A new algorithms to track fast ions in the magnetic field of a fusion reactor Daniel Ruprecht, TUHH, Institut für Mathematik, Lehrstuhl für Computational Mathematics, Am SchwarzenbergCampus 3, Gebäude E, 21073 Hamburg The plasma in a fusion reactor is heated by neutral beam injection: injecting high energy neutrons which quickly ionize and swirl around in the reactor's magnetic fiel. Modelling this process requires solving the Lorentz equations numerically over long times (up to a second) with very small time steps (order of nanoseconds), which means very many time steps and thus long simulation times (from days up to a week). The talk will introduce GMRESBorisSDC (GBSDC), a new time stepping algorithm that can reduce computational cost compared to the currently used Boris method. The method is a potpourri of various numerical techniques, including the GMRES linear solver, spectral deferred corrections, the velocity Verlet scheme and the Boris trick. I will describe the algorithm and show examples of its performance for benchmarks with varying degree of realism. 
12.11.19  15:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Project presentations of Canadian interns Josiah Vandewetering and Braeden Syrnyk During their workterm at TUHH the two Canadian students worked on projects relating to current research in the institute. 
05.11.19  16:30  Am SchwarzenbergCampus 3 (E), Raum 3.091 
Kempe Chains and Rooted Minors Samuel Mohr, Technische Universität Ilmenau 
24.10.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Observability Estimates in Banach Spaces and Applications Dennis Gallaun In this talk we study sufficient conditions for obserability of systems in Banach spaces. In an abstract Banach space setting we show that an uncertainty relation together with a dissipation estimate implies an observability estimate with explicit dependence on the model parameters. Our approach unifies and generalizes the respective advantages from earlier results obtained in the context of Hilbert spaces. As an application we consider elliptic operators on Lp spaces. Combined with the wellknown relation between observability and controllability we derive sufficient conditions for nullcontrollability and bounds on the control cost. 
17.10.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Extension of vectorvalued functions and weakstrong principles Karsten Kruse We give a unified approach to handle the problem of extending functions with values in a locally convex Hausdorff space $E$ over the field $\mathbb{K}=\mathbb{R}$ or $\mathbb{C}$, which have weak extensions in a space $\mathcal{F}(\Omega,\mathbb{K})$ of scalarvalued functions on a set $\Omega$, to functions in a vectorvalued counterpart $\mathcal{F}(\Omega,E)$ of $\mathcal{F}(\Omega,\mathbb{K})$. The main tool is the representation of vectorvalued functions as linear continuous operators. 
25.09.19  10:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Stabilität gewöhnlicher Differentialgleichungen (Bachelorarbeit) Patrizia Hermann 
23.09.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Erkennung und Vorhersage von Meinungsbildern anhand neuronaler Netze (Bachelorarbeit) Nesrine Zarrouki 
09.09.19  15:00  Raum H0.03 
Application of Hierarchical Matrices to Scattered Data Interpolation [Promotionsvortrag] Michael Wende 
30.08.19  15:00  Raum H 0.07 
Inexact Iterative Projection Methods for Linear and Nonlinear Eigenvalue Problems Nicolai Rehbein 
15.08.19  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Bildbasierte Verarbeitung von Pulverbett und Schmelzbadaufnahmen der additiven Fertigung von Ti6Al4V [Masterarbeit] Julia Schawaller, Studiengang TM, jetzt Airbus 
11.07.19  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Factorization and Symmetrization of stabilized Gaussian RBFs* Sabine Le Borne, Technische Universität Hamburg, Institut für Mathematik, Lehrstuhl Numerische Mathematik, Am SchwarzenbergCampus 3, Gebäude E, 21073 Hamburg 
09.07.19  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Segmentierung von Fischröntgenbildern mittels Machine Learning [Masterarbeit] Stefan Dübel 
04.07.19  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Analysis of the discretization error in the RBFFD method Willi Leinen 
27.06.19  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Inexakte iterative Projektionsverfahren für lineare und nichtlineare Eigenwertprobleme Nicolai Rehbein, Institut für Mathematik, TUHH Ich präsentiere einen allgemeinen Ansatz für das JacobiDavidsonVerfahren basierend auf einem beliebigen iterativen Verfahren zum Lösen eines linearen oder nichtlinearen Eigenwertproblems. Die Auswirkung eines inexakten Lösens der Korrekturgleichung wird betrachtet und hieraus kann lineare Konvergenz für drei Fälle von verschiedene Vorbedingungen bewiesen werden. 
21.06.19  13:45  Am SchwarzenbergCampus 3 (D), Raum D1.021 
Recent Applications of Deep Learning, Wavelet Theory and Persistent Homology Mijail Guillemard We give an overview or recent developments on Deep Learning, its relations to wavelet 
06.06.19  16:00  D1.021 
On differentialalgebraic equations in infinite dimensions Sascha Trostorff, CAU Kiel, Arbeitsbereich Analysis, LudewigMeynStraße 4, 24098 Kiel We consider differentialalgebraic equations on (possibly) infinite dimensional Hilbert spaces, that is, we consider equations of the form 
24.05.19  13:45  D1.021 
Schneiden, Kleben, Glattbügeln  Spektraltheorie für Heimwerker Marko Lindner, TUHH, Institut fuer Mathematik, Lehrstuhl fuer angewandte Analysis Es geht um eine Fortführung des Vortrages von Anfang Februar: 
21.05.19  17:30  Am SchwarzenbergCampus 3 (E), Raum 3.091 
A coset enumeration approach to CSP refutation (Masterarbeit) Joshua Stock 
17.05.19  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Radiale Basisfunktionen – ein Crashkurs JensPeter M. Zemke, Institut für Mathematik, Lehrstuhl für numerische Mathematik Radiale Basisfunktionen (RBF) dienen der Interpolation und Approximation mehrdimensionaler verteilter Daten. In diesem Vortrag werden RBF motiviert, die positive Definitheit und damit eindeutige Lösbarkeit der Interpolationsaufgabe einiger RBF hergeleitet, sowie Erweiterungen, wie bedingt definite RBF und flache RBF, vorgestellt. Der Fokus liegt hierbei auf den Beweistechniken und den Ideen hinter RBF. 
10.05.19  13:45  D1.021 
A Model for the Description of Fluid Flow Fabian Gabel Based on 6 + 2 assumptions, we will derive a model (a system of PDEs) with the purpose to describe the movement of a fluid. Ideally, at the end of the talk, we will have arrived at the incompressible NavierStokes equations. 
03.05.19  13:45  H0.09 
Mathematical basics of general relativity II Jan Meichsner, TUHH, Institut fuer Mathematik, Lehrstuhl fuer angewandte Analysis Part II of the presentation on general relativity. In this part we will talk about the basic equations and how physical quantities are described in terms of mathematical objects. 
26.04.19  13:45  H0.07 
Mathematical basics of general relativity I Jan Meichsner, TUHH, Institut fuer Mathematik, Lehrstuhl fuer angewandte Analysis I am not an expert on the field but during my studies I spent some time on understanding the mathematical basics of the general theory of relativity. I would present them in two parts. In the first part on the 26th of April I would concentrate on basics of differential geometry which are needed to describe the mathematics of the theory. In a second part on the 3rd of May I would explain how the before introduced structures are used to create a mathematical model of general relativity. 
25.04.19  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Kernschätzung bei Aggregationsproblemen mit radialen Basisfunktionen (Masterarbeit, TM) Torben Jentzsch 
24.04.19  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
A Riesz Decomposition Theorem for Schrödinger Operators on Graphs Florian Fischer, Universität Potsdam, Institut für Mathematik In the classical potential theory on the Euclidean space and in the potential theory of transient Markov chains a unique decomposition of superharmonic functions into a harmonic and a potential part is wellknown. In this talk the basic concepts and ideas to gain such a decomposition for Schrödinger operators on graphs will be shown. The talk will show results of my master's thesis supervised by Matthias Keller. 
12.04.19  13:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Monotonie von Spektren für metrische Graphen Christian Seifert Wie verändert sich das Spektrum des LaplaceOperators (oder allgemeiner von SchrödingerOperatoren) auf metrischen Graphen unter Variation der Graphenparameter? Einige Antworten auf die Frage gibt es im Vortrag. 
26.03.19  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Morphologische Operationen in der Bildverarbeitung [Bachelorarbeit] Jasper Reese, TMStudent 
22.03.19  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Solitonen der KdVGleichung in Netzwerken [Bachelorarbeit] Mitja Roeder 
22.03.19  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Neuronale Netze und die Aktivierung von Neuronen [Bachelorarbeit] Cornelia Hofsäß 
28.02.19  15:30  Am SchwarzenbergCampus 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 SchwarzenbergCampus 3 (E), Raum 3.074 
Accessibility Assistance for the Interactive Navigation of Texts [Masterarbeit] Imad Hamoumi 
06.02.19  13:30  Am SchwarzenbergCampus 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.) 
28.01.19  13:15  H0.08 
Extrapolation spaces and DeschSchappacher perturbations of bicontinuous semigroups* Christian Budde, Bergische Universität Wuppertal, Arbeitsgruppe Funktionalanalysis We construct extrapolation spaces for nondensely defined (weak) HilleYosida operators. In particular, we discuss extrapolation of bicontinuous semigroups. As an application we present a DeschSchappacher 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, ChristianAlbrechtsUniversität 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 Bairetype 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), 1924). 
17.01.19  14:00  Am SchwarzenbergCampus 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. 
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 SchwarzenbergCampus 3 (E), Raum 3.074 
Knochendetektion in Röntgenbildern mittels Deep Learning [Forschungsprojektarbeit] Stefan Dübel 
13.12.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Solving PDEs by the RBFFD approach Willi Leinen I will present an introduction of the RBFFD method and properties of the arising linear systems. 
06.12.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Challenges for driftdiffusion simulations of semiconductors: A comparative study of different discretization philosophies Dirk Peschka, WeierstraßInstitut, 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, finiteelement as well as Voronoi finitevolume discretization schemes for the driftdiffusion equations describing charge transport in bulk semiconductor devices, i.e., the van Roosbroeck system. 
06.12.18  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Hot spots of quantum graphs Jonathan Rohleder, Matematiska institutionen, Stockholms universitet The Hot Spots Conjecture of J. Rauch asserts that the hottest and coldest points of an insulated body should move towards its boundary for large times, if the insulation is perfect. Via the semigroup associated with the Neumann Laplacian this reduces to proving that maximum and minimum of the eigenfunction(s) associated with the smallest positive eigenvalue are located on the boundary. This conjecture is not true in full generality but is currently open, for example, for convex domains. 
29.11.18  14:00  D1.024 
Approximation techniques for passive mechanical control systems* Ines Dorschky, Fachbereich Mathematik, Universität Hamburg In this talk we study approximation techniques for inputoutput systems, which appear in the modeling process of mechanical systems. So, the focus will be on linear dynamical systems with a second derivative term. 
27.11.18  16:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Fast winning strategies in biased Maker{Breaker graph games Mirjana Mikalacki, University of Novi Sad, Faculty of Sciences, Department of Mathematics and Informatics Abstract 
22.11.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Chernoff approximation of operator semigroups Yana Kinderknecht, Universität des Saarlandes, Fb. Mathematik In this talk we outline classical connections between such mathematical objects as operator semigroups, evolution equations and Markov processes. Further, we present a method to approximate operator semigroups with the help of the Chernoff theorem. Many \emph{Chernoff approximations} lead to representations of solutions of (corresponding) evolution equations in the form of limits of $n$fold iterated integrals of elementary functions when $n$ tends to infinity. Such representations are called \emph{Feynman formulae}. They can be used for direct computations, modelling of the related dynamics, simulation of underlying stochastic processes. 
21.11.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Domino towers (Including: How to count stuff using generating functions) Alexander Haupt The original problem of counting domino towers was first studied by G. Viennot in 1985, see also D. Zeilberger (The Amazing 3^n Theorem). We analyse a generalisation of domino towers that was proposed by T. M. Brown (J. Integer Seq. 20.3 (2017), Art. 17.3.1), which we call Somino towers. After establishing an equation that the generating function must satisfy and applying the Lagrange Inversion Formula, we find a closed formula for the number of towers. 
15.11.18  14:00  D1.024 
Observability for Systems in Banach spaces  Part II* Christian Seifert This talk is divided into two parts. The first part will be given on Thursday 08.11.18 by Dennis Gallaun. 
08.11.18  13:30  D1.024 
Observability for Systems in Banach spaces  Part I* Dennis Gallaun This talk is divided into two parts. The second part will be given on Thursday 15.11.18 by Christian Seifert. 
02.11.18  11:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Analyzing MRI Data using Geometric Deep Learning (Bachelor Thesis) Daniel Klisch 
01.11.18  14:15 
On a Numerical Solution Algorithm for the NavierStokes Equations and the Stokes Resolvent Problem in L^p Fabian Gabel My talk will consist of three short, independent parts, the first one being a quick introduction of myself. In the second and the third part, I will give an ''easytodigest'' survey of my graduate theses [1,2]. 

18.10.18  13:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Series representations in spaces of vectorvalued functions* Karsten Kruse It is a classical result that every $\mathbb{C}$valued holomorphic function has a local power series representation. 
11.10.18  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Konstruktion aufspannender Strukturen in WalkerBreakerSpielen Jonas Eckhoff BAVortrag 
11.10.18  14:00  D1.024 
Existence and Uniqueness of the Harmonic Extension Approach to Fractional Powers of Linear Operators* Jan Meichsner, Institut fuer Mathematik, Lehrstuhl angewandte Analysis, TUHH This talk will be an extended version of the talk I gave on the SOTA 2018 in Poland. 
26.09.18  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Verschiedene Ansätze zur Bildzerlegung Malte Seemann 
26.09.18  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Eindimensionale Quasikristalle, endliche Abschnitte und Invertierbarkeit [Bachelorarbeit] Luis Weber 
26.09.18  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Quasiperiodische Schrödingeroperatoren und Konditionszahlen [Bachelorarbeit] Jonas Sattler 
25.09.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
On the Game of Lazy Cops and Robbers on Graphs (MasterVortrag) Fabian Hamann 
25.09.18  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Ein Randwertproblem für die MaxwellGleichungen auf Mannigfaltigkeiten (Bachelorvortrag) Dennis Schmeckpeper 
13.09.18  10:00  Raum 3.008 in Gebäude L / DE17 
Eine körpergebundene integrale Methode zur Simulation von strömungsinduziertem Schall nach FfowcsWilliamsHawkings (BachelorVortrag) Konrad Scheffler 
06.09.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Utilizing Geometry of SmoothnessIncreasingAccuracyConserving (SIAC) filters for reduced errors Prof. Dr. Jennifer Ryan, Mathematics, University of East Anglia SmoothnessIncreasing AccuracyConserving (SIAC) filters for Discontinuous Galerkin (DG) methods are designed to increase the smoothness and improve the convergence rate of the DG solution form p+1 to 2p+1 through postprocessing. However, introducing these filters can be challenging for multidimensional data since a tensor product filter grows in support size as the field dimension increases [(3p+2)*h]^d, where p + the polynomial order and d is the dimension. This becomes computationally prohibitive as the dimension increases. An alternative approach is to utilize a onedimensional univariate filter. In this talk we introduce the Line SIAC filter and explore how the orientation, structure and filter size affect the order of accuracy and global errors. We show how line filtering preserves the properties of traditional tensor product filtering, including smoothness and improvement in the convergence rate, given an appropriate rotation. Furthermore, numerical experiments are included, exhibiting how these filters achieve the same accuracy at significantly lower computational costs. 
09.08.18  15:45  H0.09 
A glimpse on interpolation theory and interpolation with mixed boundary conditions* Sebastian Bechtel, Arbeitsgruppe Analysis, TU Darmstadt, Schlossgartenstrasse 7, 64289 Darmstadt First, we give a short introduction to abstraction interpolation theory and 
25.07.18  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Iterative Löser für RBF Kollokation zur Lösung von partiellen Differentialgleichungen (Bachelorarbeit) Felix Kieckhäfer, Mathematik 
19.07.18  15:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Quantitative unique continuation principles and application to control theory for the heat equation Martin Tautenhahn, TU Chemnitz, Fakultät für Mathematik This talk is divided into two. In the first part we discuss a socalled scalefree and quantitative unique continuation principle for spectral projectors of Schr\''odinger operators. 
17.07.18  11:00  H  SBC5 / H0.06 
Maximum number of cliquefree edge coloring in graphs Hiep Han, Universidad de Santiago de Chile 
17.07.18  10:00  H  SBC5 / H0.06 
Gallai's Conjecture for regular graphs and planar graphs Andrea Jimenez, Universidad de Valparaíso 
12.07.18  15:45  tba 
Sparse Frequency Estimation* Benedikt Diederichs, Fachbereich Mathematik, Universität Hamburg Prony's problem  estimating the frequencies of an exponential sum  and its higher dimensional 
04.07.18  13:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Image segmentation methods and an application to brain images. Christoph Nicolai 
28.06.18  15:45  Am SchwarzenbergCampus (D), Raum D1.021 
A minimax principle in spectral gaps* Albrecht Seelmann, Fakultät für Mathematik  Technische Universität Dortmund In [Doc. Math. 4 (1999),275283], Griesemer, Lewis, and Siedentop devised an abstract minimax principle for eigenvalues in spectral gaps of perturbed selfadjoint operators. We show that this minimax principle can be adapted to the particular situation of bounded additive perturbations with hypotheses that are easier to check in this case. The latter is demonstrated in the framework of the DavisKahan sin(2\Theta) theorem. 
27.06.18  13:00  Am SchwarzenbergCampus 1 (A), Raum A 0.14 
Tiling edgecoloured complete graphs with few pieces Jan Corsten, London School of Economics, Department of Mathematics 
21.06.18  15:30  Am SchwarzenbergCampus 5 (H), Raum H0.05 
Poisson local eigenvalue statistics for continuum random Schrödinger operators Adrian Dietlein, LMU München, Mathematisches Institut I'll start with a short recap of the lattice Anderson 
07.06.18  15:45  tba 
SilvestreCaffarelli approach to Fractional Powers of Linear Operators* Jan Meichsner We are going to discuss (again) the approach of describing fractional powers of linear operators on 
28.05.18  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Predicting Companies Mentioned in News Articles, a Comparison of Two Approaches: Latent Dirichlet Allocation with kNearest Neighbor versus Bag of Words with kNearest Neighbor [Projektarbeit] Max Lübbering 
17.05.18  16:30  TUHH, Gebäude A, Raum A0.19 
On the stability of Prony's method* Stefan Kunis, Institut für Mathematik, Uni Osnabrück 
16.05.18  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Kantenerhaltendes Entrauschen mittels bilateraler Filter [Bachelorarbeit] Leon Haag, Studiengang TM 
14.05.18  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
A Comparison of Distance Metrics in Collaborative Recommender Systems [Projektarbeit] Imad Hamoumi 
02.05.18  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Random Walks On Graphs [Bachelorarbeit] Scott Huntington, Studiengang CS 
26.04.18  15:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Polynomial chaos: applications in electrical engineering and bounds Eduard Frick The study of electromagnetic fields in 2D circuits often leads to resonances. We use a polynomial chaos expansion (due to uncertain circuit parameters), which is analytically and numerically troublesome near the resonance frequencies. As a toy model for the convergence of the polynomial chaos expansion, we look at the parallel RLC circuit with uncertain capacitance and give $L^2$ error bounds depending on the degree of the expansion, the random distribution, the distance to resonance and the socalled quality factor of the circuit (which is a measure for the damping). 
25.04.18  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Nichtparametrische Methoden der Bildregistrierung [Masterarbeit] Max Ansorge, TMStudent 
24.04.18  16:15  Geomatikum (Bundesstraße 55), Raum 1240 
Strukturierte Pseudospektren in der Systemtheorie Dennis Gallaun, Institut für Mathematik Im Rahmen des LotharCollatzSeminars spreche ich am Geomatikum (Uni Hamburg) über strukturierte Pseudospektren in der Systemtheorie. 
22.03.18  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Lanczos' Algorithm in Finite Precision and Quantum Mechanics JensPeter M. Zemke 
21.03.18  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Algebraische Präkonditionierer für Interpolationsaufgaben mit radialen Basisfunktionen Michael Wende Interpolationsaufgaben mit radialen Basisfunktionen fuehren auf vollbesetzte Sattelpunktprobleme, deren iterative Loesung eine Praekonditionierung erfordert. Die Systemmatrizen koennen als HMatrizen approximiert und fuer die Konstruktion algebraischer Praekonditionierer verwendet werden. Als Praekonditionierer verwenden wir die Nullraummethode sowie ein Gebietszerlegungsverfahren. Mittels der Nullraummethode kann die Loesung des indefiniten Systems im Wesentlichen auf die Loesung eines positiv definiten Systems geringfügig kleinerer Groesse zurueckgefuehrt werden. Die positiv definiten Systeme koennen mit einer approximativen CholeskyZerlegung in der Arithmetik hierarchischer Matrizen praekonditioniert werden. Kleinere Probleme werden auf diese Art zufriedenstellend geloest, aber fuer groessere Punktzahlen nimmt die Effektivität der CholeskyPraekonditionierung ab. 
19.03.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Physikalisch motivierte Untersuchungen der Kondition von ScharfetterGummel Matrizen [Bachelorarbeit] Judith Angel 
19.03.18  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Polynomielles Chaos: Abschätzungen und Anwendungen in der Elektrotechnik [Bachelorarbeit] Katharina Klioba, Studiengang TM 
09.03.18  11:00  Am SchwarzenbergCampus 4 (D), Raum 1.021 
Spectral asymptotics of Robin Laplacians on polygonal domains Magda Khalile, Université ParisSud Let \Omgea\subseteq\R^2 be a curvilinear polygon and Q_\Omega^\gamma be the Laplacian in L_2(\Omega) with the Robin boundary condition \partial_\nu \psi = \gamma \psi, where \partial_\nu is the outer normal derivative and \gamma>0. We are interested in the behavior of the eigenvalues of Q_\Omega^\gamma as \gamma becomes large. We prove that there exists N_\Omega \in\N such that the asymptotics of the N_\Omega first eigenvalues of Q_\Omega^\gamma is determined at the leading order by those of model operators associated with the vertices: the Robin Laplacians acting on the tangent sectors associated with \partial\Omega. In the particular case of a polygon with straight edges the N_\Omega first eigenpairs are exponentially close to those of the model operators. Moreover, if the polygon admits only nonresonant or concave corners, we prove that, for any fixed j\in\N, the N_\Omega+j eigenvalue E_{N_\Omega+j}(Q_\Omega^\gamma) behaves as E_{N_\Omega+j}(Q_\Omega^\gamma) = \gamma^2+\mu_j^D+o(1) as \gamma\to\infty, where \mu_j^D stands for the jth eigenvalue of the operator D_1\oplus\ldots\oplus D_M and Dn denotes the onedimensional Laplacian on (0,l_n), where l_n is the length of the nth side of \Omega, with the Dirichlet boundary condition. Finally, we prove a Weyl asymptotics for the eigenvalue 
01.02.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Multivariate PopulationsbilanzSysteme Robin Ahrens, E10 PopulationsBilanzen und ihre Simulation spielen in vielen Prozessen der Chemie, Pharmazie und Biotechnolgie eine zunehmend wichtige Rolle. Partikel werden dabei anhand bestimmter Eigenschaften wie Masse oder Volumen gezählt. Ein wichtiger Teil dieser Simulationen ist die Aggregation. 
25.01.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Korrektur der chromatischen Aberration von Objektiven [Bachelorarbeit] Christopher Göthel, Studiengang TM Kooperation mit der Basler AG 
11.01.18  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Image Outliers Detection and GUI Automation [Projektarbeit] Intsar Saeed 
21.12.17  14:00  Am SchwarzenbergCampus 4 (D), Raum 1.023 
Lineare Relationen und Randtripel Dr. Christian Kühn, TUHH, Am SchwarzenbergCampus 3 Teil 2 des Vortrags über lineare Relationen und Randtripel. 
20.12.17  14:00  Am SchwarzenbergCampus 5 (H), Raum H0.06 
Packing nearly optimal Ramsey R(3,t) graphs Prof. Lutz Warnke, Georgia Institute of Technology Auf Homepage hochgeladen. 
14.12.17  14:30  Am SchwarzenbergCampus 4 (D), Raum 1.021 
Lineare Relationen und Randtripel Christian Kühn Ist S ein symmetrischer Operator in einem Hilbertraum, so stellt sich oft die Frage, welche selbstadjungierten Erweiterungen der Operator S hat und ob sich Aussagen über die Spektren (beispielsweise über die Eigenwerte) dieser Erweiterungen machen lassen. Ein mathematisches Konzept, welches hierbei hilfreich sein kann, ist das Konzept der Randtripel. Dabei stellt es sich als hilfreich heraus, nicht nur Operatoren sondern auch lineare Relationen (''mehrwertige Operatoren'') zu betrachten. 
23.11.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Strukturierte Pseudospektren in der Systemtheorie Dennis Gallaun In diesem Vortrag stelle ich mich und meine Masterarbeit kurz vor. 
16.11.17  14:00  D  SBC4, D1.021 
A bound on the averaged spectral shift function and a lower bound on the density of states for random Schrödinger operators on R^d Martin Gebert, King's College London We prove a locally uniform lower bound on the density of states of continuum random Schrödinger operators in the localised regime. The main technical ingredient is a new bound on the expectation of the spectral shift function for random Schrödinger operators in the localised regime, corresponding to a change from Dirichlet to Neumann boundary conditions along the boundary of a finite volume. The bound scales with the surface area. (Joint with Adrian Dietlein, Abel Klein, Peter Hislop, Peter Müller) 
09.11.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Gewichtete positiv definite Kernel / Simulation des Kühlvorgangs eines Fluidgefüllten Behälters mit OpenFOAM Vincent Griem Willi Leinen Wir beiden stellen uns und unsere Masterarbeiten jeweils kurz vor. 
12.10.17  13:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Acceration of Path Computations for Electrical Harnesses in Aircrafts [Bachelorarbeit] Julia Schawaller 
26.09.17  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Approximation einer Randintegralgleichung [Bachelorarbeit] Riko Ukena, Studiengang TM 
26.09.17  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Strukturierte Pseudospektren in der Systemtheorie [Masterarbeit] Dennis Gallaun, Studiengang TM (erster ''eigener'' Absolvent), bald WiMi @ E10 Strukturierte Pseudospektren sind ein wichtiges graphisches Werkzeug in der Stabilitätstheorie endlichdimensionaler linearer Systeme mit ungenauen Parametern. In diesem Vortrag beschäftigen wir uns mit der Verallgemeinerung strukturierter Pseudospektren auf unendlichdimensionale Systeme und gehen auf den Bezug zur Stabilität stark stetiger Halbgruppen ein. 
22.09.17  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Verhalten und Anwendbarkeit von künstlichen neuronalen Netzen für kleine Datenmengen [Projekarbeit] Marcel Bengs, Student Theoretische Maschinebau 
30.08.17  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Simulation der Wärmeleitungsgleichung in zufälligen Medien [Bachelorarbeit] Björn Przybyla 
25.08.17  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Application of Convolutional Neural Networks for Pitch Detection [Masterarbeit] Carl Henning Cabos 
13.07.17  14:15  Am SchwarzenbergCampus 1 (A), Raum A0.10 
Allowing nonsymmetric gauge bodies helps simplifying the theory of radii functionals Dr. René Brandenberg, Zentrum Mathematik, Technische Universität München We all know that sometimes problems get easier by generalizing them. In this talk we want to present several recent results on radii functionals of convex bodies. This results were possible allowing nonsymmetric gauge bodies, where in the past only 
21.06.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Construction of Traces of Dirichlet forms Ali BenAmor, Department of Mathematics, Faculty of Sciences of Gabes, University of Gabes, Tunisia 
15.06.17  14:45  Raum H  SBC5 H0.03 (noch unbestaetigt) 
Bistetige Halbgruppen* Jan Meichsner, Institut fuer Mathematik, Lehrstuhl angewandte Analysis, TUHH In dem Vortrag wird es um bistetige Halbgruppen gehen. Das Konzept geht auf die Dissertation 
11.05.17  15:45  Am SchwarzenbergCampus (H), Raum H0.04 
Oszillationstheorie für JacobiOperatoren mit unendlichdimensionalen Fasern Julian Großmann Die Sturm’sche Oszillationstheorie stammt von CharlesFrançois Sturm um 1830, und bezieht sich meistens auf sogenannte SturmLiouvilleProbleme, d.h. Eigenwertprobleme für gewisse Differentialgleichungen. Im Vortrag wird das diskrete Analogon davon betrachtet und in Verbindung mit dem spektralen Fluss in vonNeumannAlgebren gebracht. 
03.05.17  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Verbesserung der Bildqualität bei Diffusionsgewichtetem MRT mit Hilfe von Inpainting [Masterarbeit] Joshua Engels 
27.04.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Schrödinger operators and singular infinite rank perturbations Christian Kühn In dem Vortrag werde ich ein abstraktes Konzept vorstellen, um selbstadjungierte Operatoren mit singulären Störungen zu untersuchen und dieses anschließend auf Schrödingeroperatoren mit DeltaInteraktionen anwenden. 
21.04.17  09:00  H 0.06 
Approximation of Spectra and Pseudospectra on a Hilbert Space [Promotionsvortrag] Torge Schmidt 
03.04.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Using neural networks to classify paths in twodimensional environments [Bachelorarbeit] Kieron Kretschmar, TMStudent 
31.03.17  14:00  H0.03 
Efficient and Accurate Evaluation of Aggregation Integrals in Population Balance Equations (Promotionsvortrag) Lusine Shahmuradyan 
27.03.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Numerische Simulation eines Modells einer Heißwasserhydrolyse (Bachelorarbeit) Thorben Abel 
28.02.17  10:00  H 0.08 
Minimierung des kleinsten Eigenwerts für LaplaceOperatoren auf metrischen Graphen [Bachelorarbeit] Yannick Jean Paul Lucien Saive, TMStudent 
15.02.17  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Präkonditionierer basierend auf filternden MatrixZerlegungen (Bachelorvortrag) Rasmus Wormstädt 
06.02.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Solving PDEs Numerically: RBF Collocation and Finite Volume Methods for Semiconductor Problems Dr. Patricio Farrell, Weierstrass Institut, Berlin Partial differential equations model a wide range of physical phenomena. 
26.01.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
The need for linear system solvers in dispersive wave modeling* Jörn Behrens, UHH Tsunami modeling is  to first (and very accurate) approximation  performed with the help of shallow water theory and equations. This is still the method of choice for many applications, including forecasting, hazard assessment and inundation modeling. However, for long propagation distances as well as highly nonuniform topographies dispersive effects become important. While truly dispersive model equations are fully threedimensional and therefore expensive with respect to computational requirements, a common approach to dispersive modeling comprises a nonhydrostatic correction of shallow water equations. In order to derive this correction term, a linear system of equations needs to be solved in each time step  even when the timestepping scheme is explicit. 
19.01.17  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Convergence of positive operator semigroups Moritz Gerlach, Universität Potsdam We give new conditions for strong convergence of positive operator 
15.12.16  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Optimierung von Pasteurisierungsprozessen Lea Versbach Ich werde in einem ca. 45 minütigen Vortrag meine Masterarbeit, die ich im Juni 2016 an der Uni Lund verteidigt habe, vorstellen. 
13.12.16  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
The essential spectrum of Toeplitz operators on the unit disk Raffael Hagger, Leibniz Universität Hannover Consider the usual function space L^2(D) on the unit disk D and 
12.12.16  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Nuklearität und Tensorprodukte* Karsten Kruse Im Vortrag wird es darum gehen, wie man eine vektorwertige Gleichung löst, wenn man die entsprechende Gleichung schon einmal skalarwertig gelöst hat. Typische Beispiele hierfür sind elliptische Differentialgleichungen. Hierbei geht es dann weniger darum, den Differentialoperator selbst zu untersuchen, sondern die Eigenschaften der Räume, auf denen er lebt. 
24.11.16  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Fractional Powers of Linear Operators* Jan Meichsner Im wesentlichen ein 60 bis 90 minütiger Arbeitsstandbericht. Es werden grundlagen der Theorie fraktionaler Operatoren erläutert und danach auf die Problematik der Einführung durch harmonische Erweiterung eingegangen. 
15.11.16  16:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Endliche Abschnitte des FibonacciHamiltonOperators [Bachelorarbeit] Hagen Söding, Studiengang TM 
10.11.16  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
KrylovraumVerfahren für Sequenzen linearer Gleichungssysteme (Masterarbeitsvortrag) Robin C. Ahrens 
02.11.16  13:30  TUHH, Gebäude A, Raum A0.19 
Vier konkrete Anwendungen von Toeplitzoperatoren* Albrecht Böttcher, TU Chemnitz Vier konkrete Anwendungen von Toeplitzoperatoren 
27.10.16  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Verschiedene Methoden der Bildrestauration [Bachelorarbeit] Franziska Sommer, Studiengang TM 
17.10.16  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Variationsmethoden in der Bildregistrierung [Bachelorarbeit] Björn Ludwig, Studiengang TM 
13.10.16  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Mehrgitterverfahren zur Lösung der Helmholtzgleichung (Bachelorarbeit) Clemens Oszkinat 
12.10.16  12:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Iterative Lösung von dünnbesetzten Systemen aus Interpolationsaufgaben mit radialen Basisfunktionen (Bachelorarbeit) Torben Jentzsch 
12.10.16  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Präkonditionierung von indefiniten Problemen in Optimierungsaufgaben im Katastrophenmanagement (Bachelorarbeit) Jannick Meyer 
22.09.16  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
LaplaceTransformation für Hyperfunktionen [Bachelorarbeit] Lars Poppe, Studiengang TM 
12.09.16  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Das IsingModell: Asymptotik von Toeplitzdeterminanten [Bachelorarbeit] Louisa Granzow, Studiengang TM 
07.09.16  16:30  Am SchwarzenbergCampus 1 (A), Raum 0.019 
3Farben RamseyZahl für pfadähnliche Graphen (Abschlussvortrag Bachelorarbeit) Charlotte Knierim, Studiengang CS 
25.08.16  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
The effect of the choice of time discretization on the accuracy of the computed population density function (Bachelorvortrag) Selma Warnecke 
21.07.16  11:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Unvollständige LRZerlegung der MatrixInversen (Bachelorvortrag) Marten Hollm 
20.07.16  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Efficient and Accurate Evaluation of Aggregation Integrals in Population Balance Equations Lusine Shahmuradyan The behaviour of particulate flow is mathematically modelled by population balance equations. The various terms of the equation model phenomena including particle transport, nucleation, growth, and aggregation. Their efficient numerical simulation requires sophisticated techniques, and various approaches proposed in the literature vary not only in computational complexity but also in the accuracy of the computed solutions. We will focus on the numerical treatment of aggregation integrals, the terms that model the aggregation process and which oftentimes dominate the overall simulation time. Within such a process, particles are characterized by a property coordinate x, e.g. the particle mass, the particle area, or the chemical composition, to mention only a few, and their distribution is quantified by a density distribution function f(x,t), which describes the property distribution of the particles at a given time t. 
20.07.16  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Leaky conical surfaces: spectral asymptotics, isoperimetric properties, and beyond Dr. Vladimir Lotoreichik, Nuclear Physics Institute, Czech Academy of Sciences, Rez near Prague 
13.07.16  13:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
HMatrix Approximation for Scattered Data Interpolation Michael Wende Scattered data interpolation refers to an interpolation problem where the data sites are distributed irregularly within some domain. An interpolant may be constructed as a linear combination of radial basis functions centered at the data sites. Finding the coefficients in this representation leads to linear equations where the system matrices are large, dense, indefinite and illconditioned. These matrices can be approximated using the framework of hierarchical matrices. We will compare different approximation methods and discuss how to construct algebraic preconditioners. 
07.07.16  14:15  Am SchwarzenbergCampus 3 (E), Raum 3.074 
IDR und Deflation Stefan Möller Es werden große dünnbesetzte Sattelpunktprobleme betrachtet, wie sie z.B. in der Strömungsmechanik auftreten. Diese i.A. unsymmetrischen und indefiniten Systeme können mittels iterativer KrylovraumVerfahren, inkl. geeigneter Präkonditionierer, gelöst werden. Insbesondere werden sogenannte induzierte DimensionsReduktionsMethoden (IDR), im Speziellen QMRIDR(s), verwendet, welche zusätzlich mit einem Deflationsansatz gepaart werden. Dabei werden Informationen aus früheren Durchläufen derart recycelt, sodass es möglich ist, Sequenzen von linearen Systemen effektiv zu lösen. Als Beispiel werden die diskretisierten OseenGleichungen betrachtet; weitere Anwendung kann dies darüber hinaus z.B. bei inneren PunkteVerfahren in der linearen Optimierung finden. 
04.07.16  16:15  Am SchwarzenbergCampus 3 (A), Raum A 1.19.1 
Oscillation in a posteriori error estimation Andreas Veeser, Dipartimento di Matematica, Universita degli Studi di Milano The goal of an a posteriori error analysis for an approximate PDE 
27.06.16  12:00  Raum H0.04 
Die Eigenwerte eines LaplaceOperators mit Robinschen Randbedingungen Dr. Konstantin Pankrashkin, Université ParisSud 
24.06.16  10:30  Am SchwarzenbergCampus 3 Building A Raum A.1.19.1 
Trefftz discontinuous Galerkin methods for wave problems Dr Andrea Moiola, University of Reading We present a spacetime discontinuous Galerkin (DG) method for linear 
26.05.16  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Iterative Gleichungslöser für Markovketten (Bachelorarbeit) JuliaSophie Jürgensen 
13.05.16  09:45  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Numerische Konvergenzanalyse für FEM auf nichtkonvexen polygonalen Gebieten Ali Azarinejat Projektarbeit 
26.04.16  16:15  Am SchwarzenbergCampus 3, Gebäude A, Raum A.0.01 und A.3.31 
Solving the Vlasov equation in lowrank tensor format* Dr. Katharina Kormann, Technische Universität München, Zentrum Mathematik  M16, Boltzmannstraße 3, 85747 Garching, Germany The evolution of a plasma in external and selfconsistent fields is modelled by the Vlasov equation for the distribution function in six dimensional phase space. Due to the high dimensionality and the development of small structures the numerical solution is very challenging. Gridbased methods 
30.03.16  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Optimale Steuerung einer Laufkatze (Bachelorarbeit) Max Ansorge 
28.01.16  15:30  Am SchwarzenbergCampus 1 (A), A1.20 
Auxiliary Space Methods for Variational Problems in H{curl)* Ralf Hiptmair, ETH Zürich Auxiliary space preconditioning targets elliptic boundary value problems discetized by means of finite elements. The idea is to use a related discrete boundary value problem, for which efficient solvers are available, as a preconditioner. The connection between both problems is established by means of a suitable prolongation operator. 
25.01.16  11:00  SBC 1, Gebäude A, Raum A3.35.1 
Interpolationsbasierte ReduzierteBasisModellierung von Lösungskurven mit Umkehrpunkten (Promotionsvortrag) Hagen Eichel 
13.11.15  09:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Optimierung von NCDaten anhand von NURBSOriginaldaten (Masterarbeit) Sven Schwermer 
05.11.15  15:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Hierarchical matrix preconditioners for linear systems in multivariate interpolation with radial basis functions (Masterarbeit) Inga Drewel 
30.10.15  11:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
PCE Erweiterung der Randintegralmethode für 2D Platinen (Bachelorarbeit) Mostafa Nawabi 
30.10.15  10:30  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Darstellung von Regelflächen als NURBS (Bachelorarbeit) Atchcharan Skandarupan 
30.09.15  09:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Zum Spektrum des Fibonacci Hamilton Operators [Bachelorarbeit] Dennis Gallaun, Studiengang TM Die Untersuchung des Elektronen und Quantentransports von Quasikristallen führt auf das Spektrum des Fibonacci Hamilton Operators. Auch mathematisch ist das Spektrum interessant: Es ist eine CantorMenge mit LebesgueMaß Null. 
28.09.15  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Theorie und Anwendung symmetrisierender Präkonditionierer für elliptische PDEs (Bachelorarbeit) Moritz Boehme Einige iterative Lösungsverfahren für lineare Gleichungssysteme sind auf die Anwendung auf symmetrisch (positiv definite) Systeme beschränkt. Wir werden theoretische Ansätze aus der Literatur diskutieren, wie nichtsymmetrische Gleichungssysteme symmetrisiert werden können, Möglichkeiten der Realisierung ausarbeiten und diese auf ihre Rechenzeit testen. Motiviert durch diese Ansätze und deren Resultate werden wir im Rahmen dieser Arbeit eine Modifizierung bzw. Kombination der Ansätze vornehmen und vergleichende Tests durchführen. 
18.09.15  14:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Rational Arnoldi methods* Prof. Lothar Reichel, Department of Mathematical Sciences, Kent State University, Ohio, USA The standard Arnoldi method is one of the most popular schemes for reducing a large matrix A to a small one. The method requires the evaluation of matrixvector products with A. Rational Arnoldi methods reduce the matrix A by both evaluating matrixvector products and solving linear systems of equations with A. Rational Arnoldi methods are attractive to use when A has a structure that allows efficient solution linear systems of equations with A. They are commonly applied to the computation of an invariant subspace of A and to the approximation of matrix functions. We discuss implementations of rational Arnoldi methods and compares their properties. 
03.09.15  10:00  Am SchwarzenbergCampus 3 (E), Raum 3.074 
Interpolationsbasierte ReduzierteBasisModellierung von Lösungskurven mit Umkehrpunkten* Hagen Eichel, Eröffnung des Promotionsverfahrens Bei der numerischen Simulation physikalischer Prozesse treten häufig große parameterabhängige nichtlineare Gleichungssysteme auf. Zur Verringerung des Rechenaufwands werden oft ReduzierteBasisMethoden verwendet, die sich in lokale und globale Methoden unterscheiden lassen, wobei letztere Umkehrpunkte bezüglich des Parameters gewöhnlich nicht zulassen. In dieser Arbeit wird ein globaler, interpolationsbasierter Ansatz für Probleme mit Umkehrpunkten entwickelt und es werden die Vorteile und Grenzen dieser Methode aufgezeigt. 
19.08.15  13:00  Am SchwarzenbergCampus 3, Raum 3.074 
Variationsmethoden in der Bildverarbeitung: Die HuberFunktion im Regularisierungsterm [Bachelorarbeit] Christoph Nicolai, Studiengang TM Viele Variationsmethoden in der mathematischen Bildverarbeitung nutzen die 1Norm des Gradienten, die sogenannte Totalvariation, als Regularisierungsterm. Diese Totalvariation hat die Eigenschaft, Kanten im Bild zuzulassen und zu erhalten. Sie kann aber auch zur Entstehung von unerwünschten Kanten beitragen, dem sogenannten StaircasingEffekt. Diese Arbeit soll die HuberFunktion, eine Kombination zweier Normen, als mögliche Alternative vorstellen. 
17.08.15  12:30  Am SchwarzenbergCampus 3, Raum 3.074 
tba Hendrik Vogt, Universität Bremen 
24.06.15  14:30  Am SchwarzenbergCampus 3, Raum 3.074 
Erstellen einer NurbsToolbox Hogir Akan BachelorVortrag 
08.06.15  13:00  Am SchwarzenbergCampus 3, Raum 3.074 
FormMethoden zur Lösung von partiellen Differentialgleichungen Karsten Poddig Bachelorvortrag 
12.05.15  13:00  Am SchwarzenbergCampus 3, Raum 3.074 
QD und LRAlgorithmen für rangstrukturierte Eigenwertaufgaben (Masterarbeitsvortrag) Michael Wende 
08.05.15  10:00  Schwarzenbergstrasse 95E, Raum 3.074 
On functional calculus estimates for TadmorRitt operators Felix Schwenninger, Twente A linear operator $T$ on a Banach space is called TadmorRitt if its spectrum is contained in the closed unit disc and the resolvent satisfies $C(T)=\sup_{z>1} \(z1)R(z,T)\<\infty$. Such operators can be seen as discrete analog for sectorial operators. 
22.04.15  15:00  Raum 0.14 in Gebäude A, Am Schwarzenberg Campus 1 
Universality results in G(n,p) Peter Allen, London School of Economics, UK We say a graph $G$ is universal for a set of graphs $\mathcal{H}$ if for each $H\in\mathcal{H}$ we have $H\subset G$. There are several results stating that the random graph $G(n,p)$ is universal for various classes of graphs $\mathcal{H}$, for appropriate functions $p=p(n)$. In order for $p$ not to be very close to one, we need the graphs in $\mathcal{H}$ to be quite sparse. There are then (at least) three natural graph classes one could consider: trees, graphs with bounded degree, and graphs with bounded degeneracy. I will outline the current state of knowledge (mainly due to other people) and sketch one or two proofs 
17.04.15  10:30  Schwarzenbergstrasse 95E, Raum 3.074 
SQPMethoden zur Strukturoptimierung von Fachwerken Eike Schröder BachelorVortrag 
09.04.15  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
On the spectrum of certain random operators: A link to Julia sets Raffael Hagger After the introduction of random matrices to nuclear physics by Eugene Wigner in 1955, random quantum systems have grown in popularity. Wigner's idea was to consider families of Hamiltonians that underlie a certain probability distribution to describe overly complicated systems. Of particular interest are, of course, the spectra of these Hamiltonians. In this talk we consider random, in general nonselfadjoint, tridiagonal operators on the Hilbert space of squaresummable sequences. To model randomness, we use an approach by Davies that eliminates all probabilistic arguments. 
19.03.15  15:00  Schwarzenbergstrasse 95E, Raum 3.074 
Orthogonalization with a nonstandard inner product and approximate inverse preconditioning* Miro Rozložník, Institute of Computer Science, Academy of Sciences of the Czech Republic, Prague, Czech Republic One of the most important and frequently used preconditioning techniques for solving symmetric positive definite systems is based on computing the approximate inverse factorizations. It is also a wellknown fact that such factors can be computed columnwise by the orthogonalization process applied to the unit basis vectors provided that we use a nonstandard inner product induced by the positive definite system matrix A. In this contribution we consider the classical GramSchmidt algorithm (CGS), the modified GramSchmidt algorithm (MGS) and also yet another variant of sequential orthogonalization, which is motivated originally by the AINV preconditioner and which uses oblique projections. 
29.01.15  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
SonneveldMethoden und ihre strukturierten Büschel (III) JensPeter M. Zemke Die von Peter Sonneveld erdachten Methoden, allen voran die neueste, IDR(s), können zur approximativen Eigenwertberechnung linearer Operatoren herangezogen werden. Im Gegensatz zu klassischen Krylovraumverfahren, welche Tridiagonal oder Hessenbergmatrizen berechnen, berechnen SonneveldMethoden Büschel aus einer BandHessenbergmatrix und einer oberen BandDreiecksmatrix, von denen einige Eigenwerte bekannt sind. Basierend auf einer trivialen Beobachtung präsentieren wir Wege, die anderen Eigenwerte stabil zu berechnen. 
29.01.15  12:00  Schwarzenbergstrasse 95E, Raum 3.074 
Decompositions of highly connected graphs into paths of length five PhD Guilherme Mota, Departamento de Ciência da Computação, Instituto de Matemática e Estatística  IME, USP, Brasil Abstract: 
22.01.15  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
SonneveldMethoden und ihre strukturierten Büschel (II) JensPeter M. Zemke Die von Peter Sonneveld erdachten Methoden, allen voran die neueste, IDR(s), können zur approximativen Eigenwertberechnung linearer Operatoren herangezogen werden. Im Gegensatz zu klassischen Krylovraumverfahren, welche Tridiagonal oder Hessenbergmatrizen berechnen, berechnen SonneveldMethoden Büschel aus einer BandHessenbergmatrix und einer oberen BandDreiecksmatrix, von denen einige Eigenwerte bekannt sind. Basierend auf einer trivialen Beobachtung präsentieren wir Wege, die anderen Eigenwerte stabil zu berechnen. 
08.01.15  12:00  Schwarzenbergstrasse 95E, Raum 3.074 
The smallestweight multiway cut problem for trees Peter Heinig, Uni HH, FSP Diskrete Mathematik, Bundesstr. 55 (Geomatikum) 20146 Hamburg Abstract: 
18.12.14  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
SonneveldMethoden und ihre strukturierten Büschel JensPeter M. Zemke Die von Peter Sonneveld erdachten Methoden, allen voran die neueste, IDR(s), können zur approximativen Eigenwertberechnung linearer Operatoren herangezogen werden. Im Gegensatz zu klassischen Krylovraumverfahren, welche Tridiagonal oder Hessenbergmatrizen berechnen, berechnen SonneveldMethoden Büschel aus einer BandHessenbergmatrix und einer oberen BandDreiecksmatrix, von denen einige Eigenwerte bekannt sind. Basierend auf einer trivialen Beobachtung präsentieren wir Wege, die anderen Eigenwerte stabil zu berechnen. 
05.12.14  14:00  Schwarzenbergstrasse 95E, Raum 3.074 
H²matrix methods for boundary integral equations* Steffen Börm, ChristianAlbrechtsUniversität Kiel Boundary integral equations are an important tool for analyzing elliptic partial differential equations arising, e.g., in structural mechanics or the simulation of acoustic or electromagnetic fields. Standard discretization techniques lead to large and densely populated matrices that require special algorithms. 
20.11.14  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
TBA Marco Frego 
13.11.14  15:30  Schwarzenbergstrasse 93, Raum A1.20 
Recursive LowRank Truncation* Wolfgang Hackbusch, MaxPlanckInstitut für Mathematik in den Naturwissenschaften The best approximation of a matrix by a lowrank matrix can be obtained by the singular value decomposition. For largesized matrices this approach is too costly. Instead one may use a block decomposition. Approximating the smaller 
10.11.14  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
Homogenization meets OperatorTheory Marcus Waurick, TU Dresden Homogenization theory comprises the study of heterogeneous 
21.10.14  15:00  Schwarzenbergstrasse 95E, Raum 3.074 
TopologieOptimierung von Fachwerkstrukturen Ali Azarinejat BachelorVortrag 
08.10.14  16:30  Schwarzenbergstrasse 95E, Raum 3.074 
Modeling and Optimization of Raw Material Blending Processes Abschlussvortrag Mas Ayca Cangel, Mathematik, Diskrete Mathematik 
22.09.14  14:00  Schwarzenbergstrasse 95E, Raum 3.074 
Implementierung der Konturintegralmethode auf ebenen Bauteilen Joshua Engels BachelorVortrag 
27.08.14  10:15  Schwarzenbergstrasse 95E, Raum 3.023/24(!) 
Direkte und inverse Spektralprobleme am Beispiel des LaplaceOperators  Was verrät das Spektrum einer Trommel über ihre Gestalt? [Bachelorarbeitsvortrag] Lennart Bargsten 
22.08.14  10:30  Schwarzenbergstrasse 95E, Raum 3.074 
Anwendung von Pseudospektren in der Regelungstechnik [Bachelorarbeitsvortrag] Moritz Wolter 
04.08.14  11:00  Schwarzenbergstrasse 95E, Raum 3.074 
Directed cycle double covers and cutobstacles Andrea Jiménez, Instituto de Matemática e Estatística da Universidade de São Paulo, Atlanta and Sao Paulo In this talk, we discuss our recent progress on the famous directed cycle double cover conjecture of Jaeger. We define the class of trigraphs and prove that a graph connections conjecture formulated on trigraphs implies general Jaeger's conjecture. In addition, we give supporting evidence for our conjecture. This is joint work with Martin Loebl. 
04.08.14  09:00  Schwarzenbergstrasse 95E, Raum 3.074 
Searching for defective subsets using queries of fixed size Dominik Vu, University of Memphis Given an $n$element set which contains a known number $d$ of unknown special elements, we are allowed to use an oracle which accepts queries of size $k$ and responds positively if at least one of the elements of the queried set is in our set of unknowns. The case of a single unknown element has been studied and solved in the past by Rényi (1961), Katona (1966) and more recently by Hosszu, Tapolcai and Wiener (2013). We generalise their results in both the adaptive (online) and nonadaptive (parallelised) case for general d. Our approach provides new links between separability and (hyper)graph girth, as well as new bounds for the problem. 
08.07.14  15:30  Schwarzenbergstrasse 95E, Raum 3.074 
TBA Helena Jenderek 
01.07.14  15:45  Schwarzenbergstrasse 95E, Raum 3.074 
Immer wieder Hurwitz Neues über unendliche, total nichtnegative Matrizen und eine alte Bemerkung B.Riemanns Dr. Prashant Batra, Institut für Rechnertechnologie, Schwarzenbergstrasse 95E, Raum 3.074 In Zusammenhang mit der Nullstellenlage von Polynomen welche ausschließlich nichtnegative Koeffizienten aufweisen wurden von Holtz und Tyaglov (SIAM Review, 2012) speziell strukturierte, unendliche Matrizen betrachtet, deren Minoren sämtlich nichtnegativ sind genau dann, wenn das Polynom nur negative Nullstellen besitzt. 
30.06.14  15:00  Schwarzenbergstrasse 95E, Raum 3.074 
Domain Decomposition for elliptic PDE eigenvalue problems* Lars Grasedyck, RWTH Aachen We consider the solution of a rather simple class of eigenvalue problems $Ax=\lambda{Mx}$ for symmetric positive definite matrices $A$,$M$ that stem, e.g., from the discretisation of a PDE eigenvalue problem. Thus, the problem is in principle simple, but the matrices $A$ and $M$ are largescale and we would like to compute all relevant eigenvalues, where relevant is to be understood in the sense that all eigenvalues should be computed that can be captured by the discretisation of the continuous PDE eigenvalue problem. 
24.06.14  15:30  Schwarzenbergstrasse 95E, Raum 3.074 
A connection between coupled and penalty projection timestepping schemes with FE spatial discretization for the NavierStokes equations* Leo Rebholz We prove that in finite element settings where the divergencefree subspace of the velocity space has optimal approximation properties, the solution of Chorin/Temam projection methods for NavierStokes equations equipped with graddiv stabilization with parameter $\gamma$, converge to the associated coupled method solution with rate $\gamma^{1}$ as $\gamma\rightarrow \infty$. We prove this first for backward Euler schemes, and then extend the results to BDF2 schemes, and finally to schemes with outflow boundary conditions. Several numerical experiments are given which verify the convergence rate, and show how using projection methods in this setting with large graddiv stabilization parameters can dramatically improve accuracy. 
20.06.14  11:15  Firma Röders, Soltau 
Formwahrende Interpolation von NCDaten [Masterarbeitsvortrag] Michael Seeck 
03.06.14  14:30  Schwarzenbergstrasse 95E, Raum 3.074 
Evaluation of Coalescence Integrals in PBE on equidistant grids Lusine Shahmuradyan 
28.05.14  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
Where is the main diagonal of my biinfinite matrix? Marko Lindner Sometimes it is convenient to have a biinfinite enumeration of the basis elements in the domain and image spaces of an operator A  leading to a representation of A by a biinfinite matrix. 
13.05.14  15:30  Schwarzenbergstrasse 95E, Raum 3.074 
tba Torge Schmidt 
08.05.14  14:00  Schwarzenbergstrasse 95E, Raum 3.074 
Applications of Tutte's tree decomposition in the enumeration of bipartite graph families Prof. Juanjo Rue Perna, FU Berlin We adapt the grammar introduced by Chapuy, Fusy, Kang and Shoilekova to study bipartite graph families which are defined by their 3connected components. More precisely, in this talk I will explain how to get the counting formulas for bipartite seriesparallel graphs (and more generally of the Ising model over this family of graphs), as well as asymptotic estimates for the number of such graphs with a fixed size. This talk is based in a work in progress joint with Kerstin Weller. 
06.05.14  15:30  Schwarzenbergstrasse 95E, Raum 3.074 
TBA Karsten Kruse 
29.04.14  15:30  Schwarzenbergstrasse 95E, Raum 3.074 
Numerical Ranges and Random Operators Raffael Hagger 
24.04.14  16:00  Schwarzenbergstrasse 95E, Raum 3.074 
Preconditioners for timedependent PDEconstrained optimization* Martin Stoll, MPI Magdeburg 
17.04.14  11:00  Schwarzenbergstrasse 95E, Raum 3.074 
Störung positiver Halbgruppen, und Kernabschätzungen Christian Seifert ... ist vielleicht nur für die Analytiker interessant. 
18.02.14  15:00  Schwarzenbergstrasse 93, Gebäude A, Raum A0.14 
Tight cycles and regular slices in dense hypergraphs Dr. Peter Allen, London School of Economics, UK We describe a general approach to the strong hypergraph regularity lemma, which we call 'regular slices', which avoids many of the usual technical complications and retains the features one would like to use in extremal hypergraph theory. This talk will avoid painful technical details in so far as that is possible and focus on an application, proving a hypergraph extension of the ErdosGallai theorem. 
18.02.14  14:00  Schwarzenbergstrasse 93, Gebäude A, Raum A0.14 
Sparse blowup lemmas and makerbreaker games Dr. Julia Böttcher, London School of Economics, UK The blowup lemma of Komlós, Sárközy and Szemerédi is an important tool for embedding large graphs H into dense graphs G. We recently obtained versions of this lemma for subgraphs G of sparse random and pseudorandom graphs. This has important applications in extremal graph theory on random graphs, but can also be used for the analysis of certain makerbreaker games. 
31.01.14  14:00  Schwarzenbergstrasse 95E, Raum 3.074 
tba Anton Schiela 
14.01.14  13:30  Schwarzenbergstrasse 95E, Raum 3.074 
Wannier transform for Schrödinger operators with aperiodic potential Siegfried Beckus, FSU Jena 
09.01.14  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
Adaptive Sparse Grids and Applications: Coping with the Curse of Dimensionality Dirk Pflüger, Stuttgart High dimensionalities are a major roadblock for the numerical solution of problems in computational sciences. Straightforward discretizations are severely limited by the curse of dimensionality, the exponential dependency of the overall computational effort on the number of dimensions. It is therefore typically not feasible to treat more than four dimensions. In this talk, I will give a short introduction to Sparse Grids, which provide a versatile way to overcome the curse of dimensionality to a large extent, and show some of their applications. A special focus will be on spatially adaptive refinement, which adapts to the peculiarities of the problem at hand, and on adapted basis functions. Both are crucial whenever only few grid points can be spent, or where realworld problems do not meet the underlying smoothness requirements. The hierarchical basis formulation of the direct Sparse Grid approach conveniently provides a reasonable criterion for spatially adaptive refinement practically for free. This can serve as a starting point to develop suitable and problemadapted modifications. 
19.12.13  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
Diskrete Mathematik an der TUHH Anusch Taraz In this talk we survey the research activities and interests of the discrete maths group at TUHH. 
12.12.13  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
Fast Convolution Lusine Shahmuradyan 
28.11.13  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
IDR Verfahren Stefan Möller 
26.11.13  13:45  Schwarzenbergstrasse 95A, Raum A1.16 
On Additivity and Fixing Numbers of Matrices: Uniqueness in Discrete Tomography Dr. Barbara Langfeld, ChristianAlbrechtsUniversitat zu Kiel This talk gives an overview of some classical and recent uniqueness results in Discrete Tomography. In the first part we will review the concept of Jadditivity and apply it to settle a problem of Kuba on 3dimensional lattice sets and a conjecture of Brunetti and Daurat on planar lattice convex sets. The second part of the talk deals with the computational complexity of finding a smallest set of lattice positions of a given lattice set whose disclosure yields uniqueness w.r.t. some given Xrays. It turns out that this problem is already NPhard in the plane and for the two standard directions. 
21.11.13  15:30  Schwarzenbergstrasse 95E, Raum 3.074 
Methoden zur Verbesserung der Interpolation von NCDaten auf Basis der kubischen Splineinterpolation Tobias Hecht 
31.10.13  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
Studie zur Kompensation von Radialen Spindelverlagerungen bei Werkzeugmaschinen Saman Fröhlich 
18.10.13  10:30  Schwarzenbergstrasse 95A, Raum A1.20 
Preconditioners for twosided eigenvalue problems and applications to model order reduction Melina Freitag, Bath, UK 
17.10.13  14:15  Schwarzenbergstrasse 95E, Raum 3.074 
On the Role of the Helmholtz Decomposition in Mixed Methods for Incompressible Flows and a New Variational Crime* Alexander Linke, WIAS Berlin According to the Helmholtz decomposition, the irrotational parts of the momentum balance equations of the incompressible NavierStokes equations are balanced by the pressure gradient. Unfortunately, nearly all mixed methods for incompressible flows violate this fundamental property, resulting in the wellknown numerical instability of poor mass conservation. The origin of this problem is the lack of L2orthogonality between discretely divergencefree velocities and irrotational vector fields. Therefore, a new variational crime for the nonconforming CrouzeixRaviart element is proposed, where divergencefree, lowestorder RaviartThomas velocity reconstructions reestablish L2orthogonality. This approach allows to construct a cheap flow discretization for general 2d and 3d simplex meshes that possesses the same advantageous robustness properties like divergencefree flow solvers. In the Stokes case, optimal apriori error estimates for the velocity gradients and the pressure are derived. Moreover, the discrete velocity is independent of the continuous pressure. Several detailed linear and nonlinear numerical examples illustrate the theoretical findings. 
08.08.13  14:00  Schwarzenbergstrasse 95E, Raum 3.074 
A Wellbalanced bicharacteristicbased scheme for twolayer shallow water flows including wet/dry fronts Michael Dudzinski 
31.07.13  10:00  Schwarzenbergstrasse 95E, Raum 1.050 
Asymmetrische Galerkinverfahren in der Signalverarbeitung (Bachelorarbeitsvortrag) Djamschid Safi 
04.07.13  14:00  Schwarzenbergstraße 95H, Raum H0.03 
Numerical Treatment of Tensors* Wolfgang Hackbusch, MaxPlanckInstitut für Mathematik in den Naturwissenschaften, Leipzig The numerical treatment of tensors and the use of tensors for various numerical problem has rapidly increased in the last time. It is now applied to many fields in analysis (treatment of pdes, representation of multivariate functions, etc.). The key for an efficient numerical treatment is a suitable format. We discuss the various formats, their properties, and operations with tensors. 
02.07.13  14:15  Big lecture hall at the Biocenter Grindel and Zoological Museum, MartinLutherKingPlatz 3, 20146 H 
Compact course: An introduction to Hmatrices, Part II Prof. Dr. Dr. h.c. Wolfgang Hackbusch 
02.07.13  10:15  Big lecture hall at the Biocenter Grindel and Zoological Museum, MartinLutherKingPlatz 3, 20146 H 
Compact course: An introduction to Hmatrices, Part I Prof. Dr. Dr. h.c. Wolfgang Hackbusch 
27.06.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Basisreduktionsmethoden für lineare und nichtlineare Systeme Hagen Eichel 
20.06.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Von zufälligen dynamischen Systemen zu präkonditionierten iterativen Lösern Helena Jenderek 
13.06.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Inexakte Projektionsverfahren zur Lösung linearer und nichtlinearer Eigenwertaufgaben Nicolai Rehbein 
06.06.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Ohne Annika Eichler 
30.05.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Zufällige Operatoren und Spektraltheorie Raffael Hagger 
29.05.13  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Geometrie und Spektraltheorie von Graphen und Dirichletformen Daniel Lenz 
29.05.13  13:30  Schwarzenbergstrasse 95E, Raum 1.050 
HMatrizen für FiniteDifferenzen Matrizen* Dominik Enseleit, UHH, UHH Die Technik der Hierarchischen Matrizen HMatrizen) ermöglicht die Berechnung einer approximativen HInversen oder HLUZerlegung in fast linearer Komplexität und kann auf diese Weise zur effizienten Lösung linearer Gleichungssysteme eingesetzt werden. Vor der Verwendung der HMatrixTechnik ist zu untersuchen, ob eine HMatrix Approximation der Inversen bzw. der Faktoren der LUZerlegung existiert. 
16.05.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Spaß mit Integraloperatoren Torge Schmidt 
25.04.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Kondensationen Prof. Dr. Wolfgang Mackens 
18.04.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Darstellung und Approximation von Tensoren im Hierarchischen Format Stefan Kühn, MPI, Leipzig Die effiziente Darstellung und Approximation von Tensoren gewinnt in vielen Anwendungsbereichen der Mathematik wie Quantenchemie und physik und auch generell innerhalb der Numerik immer mehr an Bedeutung. In diesem Vortrag werden wir ein neues Format zur Darstellung von hochdimensionalen 
31.01.13  14:00  Schwarzenbergstrasse 95E, Raum 1.050 
Variationelle Charakterisierung von Eigenwerten nichtlinearer Eigenwertaufgaben Heinrich Voß 
30.01.13  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Potentialstörungen akkretiver Operatoren und elliptische Operatoren in Divergenzform Hendrik Vogt 
22.01.13  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
TitchmarshWeyl theory for elliptic differential operators on unbounded domains* Jussi Behrndt, TU Graz, Österreich In this talk we describe the spectral properties of selfadjoint Schrödinger operators on unbounded domains with 
19.12.12  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Wissenswertes über KrylovRaumVerfahren JensPeter M. Zemke 
17.12.12  10:00  Schwarzenbergstrasse 95E, Raum 1.050 
Some relations between discrete and continuous Laplacians, and averaging operators on graphs Dr. rer. nat. Konstantin Pankrashkin 
12.12.12  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Robust successive computation of eigenpairs for nonlinear eigenvalue problems* Cedric Effenberger, École polytechnique fédérale de Lausanne EPFL, Lausanne We consider eigenvalue problems which are nonlinear in the eigenvalue 
05.12.12  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Verschiedene Transporteigenschaften Christian Seifert 
28.11.12  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Invariant pairs for nonlinear eigenvalue problems* Prof. Dr. Daniel Kressner, École polytechnique fédérale de Lausanne EPFL, Lausanne The concept of invariant subspaces is fundamental to linear eigenvalue problems and provides an important theoretical foundation in the design of numerical eigenvalue solvers. It turns out that there is no straightforward extension of this concept to eigenvalue problems that are nonlinear in the eigenvalue parameter. One obstacle is that eigenvectors belonging to different eigenvalues may become linearly dependent in the nonlinear case. Invariant pairs offer an elegant way to avoid this obstacle and appear to be the most natural extension of invariant subspaces. In this talk, we give an overview of the properties of invariant pairs and explain how they can be used in the design of numerical algorithms for nonlinear eigenvalue problems, as they arise for example in band diagram calculations for photonic crystals and fluidstructure interaction problems. 
21.11.12  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Über kleine, große und ganz große Matrizen Marko Lindner 
31.10.12  15:00  Schwarzenbergstrasse 95E, Raum 1.050 
Ein Streifzug durch allerlei Sabine Le Borne 
24.10.12  15:00  Schwarzenbergstrasse 95, Raum 1.050 
SchrödingerOperatoren mit kompakter Resolvente* Peter Stollmann, TU Chemnitz, TU Chemnitz, Fakultät für Mathematik, 09107 Chemnitz Ein klassischer Satz von Friedrichs besagt, dass Schrödingeroperatoren kompakte Resolvente besitzen, wenn das zugrundeliegende Potential bei Unendlich gegen Unendlich geht. In diesem Vortrag werden wir einen einfachen Beweis einer Verallgemeinerung präsentieren, basierend auf einer gemeinsamen Arbeit mit D. Lenz (Jena) und D. Wingert. 
02.10.12  14:00  Schwarzenbergstrasse 95 E, Raum 3.032 
Varianten der Eigenvektorberechnung mittels
Algorithmen basierend auf Induzierter
DimensionsReduktion (IDR) (Bachelorarbeitsvortrag) Nina T. Piontek 
26.09.12  16:00  Schwarzenbergstrasse 95 D, Raum D0013 
Anwendung eines auf Induzierter
DimensionsReduktion basierenden
Eigenwertlösers auf ein FEMModell (Bachelorarbeitsvortrag) Aulikki Wilhelmi genannt Hofmann 
26.09.12  15:00  Schwarzenbergstrasse 95 D, Raum D0013 
Vergleich der drei Hauptklassen von
KrylovRaumVerfahren zur
Eigenwertberechnung an ausgewählten Beispielen
aus der FEMAnalyse (Bachelorarbeitsvortrag) Sarajaddin Rahmani 
05.09.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Contributions to the Optimal Choice of Parameters in Induced Dimension Reduction algorithms (Masterarbeitsvortrag) Olaf Rendel 
22.08.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Vergleich von Lanczos und SonneveldAlgorithmen zur Lösung großer dünnbesetzter linearer Gleichungssysteme über endlichen Körpern an Beispielen aus der Kryptographie (Bachelorarbeitsvortrag) Matthias Marx 
08.08.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Zur optimalen Wahl der Parameter in präkonditioniertem MultiShift QMRIDR am Beispiel der HelmholtzGleichung (Bachelorarbeitsvortrag) Michael Garben 
22.06.12  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Vergleich dreier Klassen von KrylovRaumVerfahren an ausgewählten Beispielen aus der FEMAnalyse (Bachelorarbeitsvortrag) Mehran Majidi 
15.06.12  09:00  Schwarzenbergstrasse 95, Raum 3.053 
Approximation of convergence rates of the Lanczos iteration through potential theory (Bachelorarbeitsvortrag) Dawid Golebiewski 
14.03.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
The Lanczos algorithms and their relations to formal orthogonal polynomials, Padé approximation, continued fractions, and the qd algorithm* Martin Gutknecht, ETH Zurich; Seminar for Applied Mathematics, LEO D3 (Leonhardstrasse 27), 8092 Zurich, Switzerland In their seminal 1952 paper on the conjugate gradient (CG) method Hestenes and Stiefel pointed out that their method, which is applicable to linear systems of equations with symmetric positive definite matrix only, is closely related to certain orthogonal polynomials, the corresponding Gauss quadrature formulas, certain continued fractions, and their convergents (or `partial sums'). The latter can be seen to be Padé approximants of a function that involves the resolvent of the matrix. 
29.02.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Solving large nonsymmetric linear systems with IDR(s) on a geographically separated cluster of parallel computers* Martin van Gijzen, Delft University of Technology; Faculty of Electrical Engineering, Mathematics and Computer Science, Mekelweg 4; 2628 CD Delft; The Netherlands The IDR(s) method is a family of fast algorithms for iteratively solving large nonsymmetric linear systems. In the talk we will discuss an IDR(s) variant that is specifically tuned for parallel and grid computing. In particular in grid computing the inner product is a bottleneck operation. We will discuss three techniques that we have used to alleviate this bottleneck in IDR(s). Firstly, the efficient and stable IDR(s)biortho method is reformulated in such a way that it has a single global synchronisation point per iteration step. Secondly, the socalled test matrix is chosen so that the work, communication, and storage involving this matrix is minimised in multicluster environments. Finally, a methodology is presented for apriori estimation of the optimal value of s using only problem and machinebased parameters. We will also discuss a preconditioned version of IDR(s) that is particularly suited for grid computing. We will illustrate our results with numerical experiments on the DAS3 Grid computer, which consists of five cluster computers located at geographically separated places in the Netherlands. 
15.02.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
An Optimization Problem Corresponding To a Nonlinear Eigenvalue Problem On a Rearrangement Class Abbasali Mohammadi 
01.02.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Inexakte Iterationsverfahren zur Berechnung von Eigenwerten Nicolai Rehbein 
18.01.12  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Studienarbeitsvortrag: Tikhonov Regularization of Large Linear Problems via Lanczos Bidiagonalization Negar Arazm 
15.12.11  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Topology and nonRocal geometry of wallbounded flows Diplomvortrag Moritz Kompenhans 
23.11.11  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Der WiedemannAlgorithmus und andere KrylovRaumVerfahren (Studienarbeitsvortrag) Raphael Elsner 
21.11.11  11:00  Schwarzenbergstrasse 95, Raum 3.053 
Linearisierung von rationalen Eigenwertaufgaben Osman Cakir 
07.09.11  14:30  Schwarzenbergstrasse 95, Raum 3.053 
Eigenwertberechnung mittels IDRStab (Studienarbeitsvortrag) Anisa Rizvanolli 
04.05.11  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Untersuchung zur Festigkeit von Schiffen mit Hilfe der iterativen Lösung linearer Systeme Osman Cakir 
06.04.11  16:15  Schwarzenbergstrasse 95, Raum 3.053 
Die modale Berechnung der Strukturverformung von Schiffen im Seegang Anne Schwenkenberg 
06.04.11  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Adaption reduzierter Basen Uwe Köcher 
06.04.11  14:00  Schwarzenbergstrasse 95, Raum 3.053 
KrylovUnterraumVerfahren für Operatoren (Studienarbeitsvortrag) Abdessalem Helal 
16.03.11  15:00  Schwarzenbergstrasse 95, Raum 3.053 
The Lanczos Algorithm in FinitePrecision Arithmetic* Ivo Panayotov, Mathematical Institute, University of Oxford, 2429 St Giles', Oxford, OX1 3LB, England The Lanczos algorithm was introduced in 1950 as means of solving eigenvalue problems. Despite its apparent elegance, the algorithm was initially neglected by the scientific community because it was observed to depart from its theoretical properties due to the effects of finiteprecision computer arithmetic. The algorithm regained popularity several decades later when it was shown that despite its departure from theory, it nevertheless produces highly accurate eigenvalue estimates. 
21.02.11  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Performance of the Preconditioned IDR(s)based Residual Reduction Method Prof. Seiji Fujino, Research Institute for Information Technology, Kyushu University, Fukuoka, Kyushu, Japan We devised an IDR(s)based SOR method and presented its effectiveness in view of efficiency and robustness by comparison with other iterative methods one year ago. In this talk, we consider the preconditioned IDR(s)based Residual Reduction (R2) method as an extension of the IDR(s)based SOR method in view of robust preconditioning. Moreover, we present numerical experiments that clearly show that our proposed IDR(s)R2 method outperforms other approaches. 
15.12.10  16:15  Schwarzenbergstrasse 95, Raum 3.053 
Inexaktes BiCGStab (Bachelorarbeitsvortrag) Deniz Ataç 
15.12.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
MatlabImplementierung eines QRAlgorithmus mit multiplen Shifts und aggressiver frühzeitiger Deflation (Studienarbeitsvortrag) Berivan Upçin 
08.12.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Singular optimal control, Lur'e equations and even matrix pencils Prof. Dr. Timo Reis, Institut für Numerische Simulation, Technische Universität HamburgHarburg Lur'e equations are a generalization of algebraic Riccati equations and they arise in linearquadratic optimal control with cost functional being singular in the input. 
24.11.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Demands of modal reanalysis techniques in Engineering Design Jiacong Yin, Peking University, China 1. A brief introduction about our group in Peking University 
09.11.10  14:00  Schwarzenbergstrasse 95, Raum 3.053 
SplineAusgleich für die glatte Approximation von NCDaten (Bachelorarbeitsvortrag) Michael Seeck 
20.10.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Entwicklung eines Algorithmus zur effektiven Lösung großer nichtlinearer Gleichungssysteme Fabian Krome 
22.09.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Eine graphische Benutzeroberfläche bei Kurvenverfolgung (Studienarbeitsvortrag) Uwe Köcher 
22.09.10  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Inexakte Inverse Iteration (Diplomarbeitsvortrag) Fatih Berber 
15.09.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Aspects of eigenvalue computations using Induced Dimension Reduction (Bachelorarbeitsvortrag) Olaf Rendel 
16.06.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Inducing dimension reduction for efficientlysolving large linear systems of equations Gerard L.G. Sleijpen, Department of Mathematics, Utrecht University, Utrecht, The Netherlands The Induced Dimension Reduction method was proposed in 1980 by Peter Sonneveld as an iterative method for solving large nonsymmetric linear systems of equations. IDR can be considered as the predecessor of methods like CGS (Conjugate Gradient Squared [Sonneveld '89]) and BiCGSTAB (BiConjugate Gradients STABilized [van der Vorst '92]). All three methods are based on efficient short recurrences. An important similarity between the methods is that they use orthogonalization with respect to a fixed `shadow residual'. Of the three methods, BiCGSTAB has gained the most popularity, and is probably still the most widely used short recurrence method for solving nonsymmetric systems. 
14.04.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Inverse Iteration, NewtonAbschätzungen und Anwendung auf RayleighQuotientenIterationen bei nichtlinearen Eigenwertproblemen Prof. Hubert Schwetlick, TU Dresden, Institut für Numerische Mathematik Bekanntlich liefert ein Schriitt $(u,\theta) \mapsto u_+^{InvIt}$ der Inversen Iteration für das nichtlineare Eigenwertproblem $T(\lambda)x=0$ dieselbe Richtung wie ein Schritt $(u,\theta) \mapsto (u_+^{Newt},\theta_+^{Newt})$ des Newtonverfahrens für das erweiterte System $T(\lambda)x=0,\;w^Hx=1$ mit einem geeigneten Skalierungsvektor $w$, d.h., es gilt $\mbox{span}\,\{u_+^{InvIt}\}=\mbox{span}\,\{u_+^{Newt}\}$. Es liegt daher nahe, zur Abschätzung der Verbesserung der Eigenvektorapproximation $u$ durch die Inverse Iteration NewtonTechniken zu verwenden. Es wird gezeigt, dass dies zu genauen Abschätzungen führt, wenn explizit mit dem Restglied zweiter Ordnung gearbeitet und dessen spezielle Produktstruktur berücksichtigt wird wie das von \textsc{Heinz Unger} [50] erstmalig (und ohne publizierten Beweis) für das lineare Problem $T(\lambda)=A\lambda I$ getan worden ist. 
17.02.10  14:00  Schwarzenbergstrasse 95, Raum 3.053 
wird noch bekannt gegeben Michael Dudzinski 
03.02.10  13:00  Schwarzenbergstrasse 95, Raum 3.053 
On the motion of several rigid bodies in an incompressible nonNewtonian fluid* Prof. Sarka Necasova, Institute of Mathematics of the Academy of Sciences, Praha, Czech Republic The motion of one or several rigid bodies in a viscous fluid occupying a bounded domain $\Omega in R^3$ represents an interesting theoretical problem featuring, among others, possible contacts of two or more solid objects. We consider the motion of several rigid bodies in a nonNewtonian fluid of a powerlaw type. Our main result establishes the existence of globalintime solutions of the associated evolutionary system, when collisions of two or more rigid objects do not appear in a finite time unless they were present initially. 
27.01.10  15:00  Schwarzenbergstrasse 95, Raum 3.053 
A selfsimilar solution for the porous medium equation in a twocomponent domain* Prof. Jan Filo, Comenius University, Bratislava, Slovak Republic We solve a particular system of nonlinear ODEs defined on the two different components of the real line connected by the nonlinear contact condition 
16.12.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Inverse iteration for purely imaginary eigenvalues with application to the detection of Hopf Bifurcations in large scale problems* Prof. Dr. Karl Meerbergen, Katholieke Universiteit, Leuven The detection of a Hopf bifurcation in a large scale dynamical system that depends on a physical parameter often consists of computing the rightmost eigenvalues of a sequence of large sparse eigenvalue problems. Guckenheimer et. al. (SINUM, 34, (1997) pp. 121) proposed a method that computes a value of the parameter that corresponds to a Hopf point without actually computing rightmost eigenvalues. This method utilises a certain sum of Kronecker products and involves the solution of matrices of squared dimension, which is impractical for large scale applications. However, if good starting guesses are available for the parameter and the purely imaginary eigenvalue at the Hopf point, then efficient algorithms are available. In this paper, we propose a method for obtaining such good starting guesses, based on finding purely imaginary eigenvalues of a twoparameter eigenvalue problem (possibly arising after a linearisation process). The problem is formulated as an inexact inverse iteration method that requires the solution of a sequence of Lyapunov equations with low rank right hand sides. It is this last fact that makes the method feasible for large systems. The power of our method is tested on numerical examples. 
04.12.09  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Introduction of IDRbased Jacobi(s), GaussSeidel(s) and SOR(s) methods and its estimation Prof. Seiji Fujino, Research Institute for Information Technology, Kyushu University, Fukuoka, Kyushu, Japan The conventional SOR (Successive OverRelaxation) method originated from the dissertation by D. Young in 1950. After that, the SOR method has been often used for the solution of problems which stem from various applications. The SOR method, however, has many issues on possibility of the solution because of no robustness of convergence of the SOR method. 
16.09.09  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Ein Verfahren zur Regularisierung von vollständigen Ausgleichsproblemen Moritz Augustin 
16.09.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Die Newton Methode und Rayleigh Quotienten Interation für das Totale Least Squares Problem Fatih Berber 
09.09.09  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Über den Einfluss eines inexakten
MatrixVektorProdukts auf Fehlerschätzungen im
Verfahren der konjugierten Gradienten Martin Müller 
02.09.09  16:15  Schwarzenbergstrasse 95, Raum 3.053 
The generalized Riemann problem (GRP) method for compressible fluid flows* Prof. Jiequan Li, School of Mathematics, Capital Normal University, Beijing, China In this talk I will briefly review the generalized Riemann problem (GRP) method for compressible fluid flows. There were originally two versions of this method: 
02.09.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
ON THE CONTROL OF NUMERICAL EFFECTS OF DISPERSION AND DISSIPATION PREVAILING IN FINITE DIFFERENCE SCHEMES* Dr. Bippine Appadu, University of Mauritius, Reduit, Mauritius In CFD, Atmospheric Sciences and Computational Aeroacoustics, many problems involve regions of discontinuity. When used to solve problems involving regions of shocks, dispersive schemes give rise to oscillations while dissipative schemes cause smearing, close to these regions of sharp gradients. 
10.07.09  10:00  Schwarzenbergstrasse 95, Gebäude D, Raum D1025 
Discrete Empirical Interpolation for Nonlinear Model Reduction* Prof. D. C. Sorensen, Rice University, Houston, Texas A dimension reduction method called Discrete Empirical Interpolation (DEIM) will be presented and shown to dramatically reduce the computational complexity of the popular Proper Orthogonal Decomposition (POD) method for constructing reducedorder models for unsteady and/or parametrized nonlinear partial differential equations (PDEs). In the presence of a general nonlinearity, the standard PODGalerkin technique reduces dimension in the sense that far fewer variables are present, but the complexity of evaluating the nonlinear term remains that of the original problem. 
17.06.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
New ideas on IDR(s) JensPeter M. Zemke 
13.05.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
On numerical simulation of flow in timedependent domains Prof. Miloslav Feistauer, KarlsUniversität Prag, Department of Numerical Mathematics The lecture will be concerned with the simulation of inviscid and viscous compressible flow in time dependent domains. The motion of the boundary of the domain occupied by the fluid is taken into account with the aid of the ALE (Arbitrary LagrangianEulerian) formulation of the Euler and NavierStokes equations describing compressible flow. The system of the governing equations is discretized in space by the discontinous Galerkin method. The time discretization is based on a semiimplicit linearized time stepping scheme, which leads to the solution of a linear algebraic system on each time level. As a result we get an efficient and robust numerical process. The applicability of the developed method will be demonstrated by some computational results obtained for flow in a channel with a moving wall and past an oscillating airfoil. 
22.04.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Berechnung erzwungener Schwingungen mittels modaler Superposition für unsymmetriche Systeme Loubna Doubli 
15.04.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
An Implementation for Model Order Reduction using Multilevel Substructuring Nicolai Rehbein 
25.03.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
On the Application of Gaussian Quadrature for the Finite Volume Evolution Galerkin Scheme Andreas Hempel 
25.02.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Multilevel discontinous Galerkin method Florian Prill 
28.01.09  15:00  Schwarzenbergstrasse 95, Raum 3.053 
IDR in variations* Prof. Martin Gutknecht, Seminar for Applied Mathematics, ETH Zurich The Induced Dimension Reduction (IDR) method is a Krylov space method for solving linear systems that was first developed by Sonneveld around 1979 and documented on three and a half pages of a 1980 proceedings paper by Wesseling and Sonneveld. Soon after IDR, Sonneveld introduced his widely applied Conjugate Gradient Squared (CGS) algorithm. Then, in 1990, van der Vorst suggested BiCGSTAB that he claimed to improve both those methods. 
17.12.08  14:30  Schwarzenbergstrasse 95, Raum 3.053 
NonOscillatory Central Schemes  a Powerful BlackBoxSolver for Hyperbolic PDE's Prof. Alexander Kurganow, Tulane University, New Orleans, USA I will first give a brief description of finitevolume, Godunovtype methods for hyperbolic systems of conservation laws. These methods consist of two types of schemes: upwind and central. My lecture will focus on the second type  nonoscillatory central schemes. 
03.12.08  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerical entropy production as a regularity/error indicator Prof. Gabriella Puppo, Dipartimento di Matematica, Politecnico di Torino,Italy Uniqueness for weak solutions of conservation laws is based on the sign of the entropy production across discontinuos solutions. Although the entropy plays a fundamental role in the theory of hyperbolic systems, it is generally not used as a computational tool. 
03.12.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Statistik nichtlinearer Vorgänge im Seegang Alexander von Graefe 
27.11.08  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Systeme gewöhnlicher Differentialgleichungen zur Beschreibung von Fußgängerdynamik Mohcine Chraibi 
20.11.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerical Solution of Conservation Laws over NonUniform, Adaptively Redefined Meshes Dr. Sfakianakis Nikos, University of Heraklion, Greece We start with a brief introduction to Conservation Laws and to their numerical solutions. Then we discuss the construction and manipulation of nonuniform meshes, using geometric properties of the numerical solution under consideration. Next, we examine properties (such as consistency, stability and order of accuracy) of numerical schemes over both uniform and nonuniform meshes. Finally, we combine a proper mesh selection mechanism with Entropy Conservative or oscillatory numerical schemes for the evolution step. 
19.11.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Über Fehlerschätzungen im Verfahren der konjugierten Gradienten Martin Müller 
29.10.08  14:00  Schwarzenbergstrasse 95, Raum 3.053 
PurifyingIteration zur Verbesserung der Approximationsgüte einer Jacobimatrixnäherung in einem QNKontext Tim Steinhoff 
20.08.08  10:00  Schwarzenbergstrasse 95, Raum 3.053 
wird noch bekannt gegeben Nam Le 
09.07.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Some strategies for improving Automated MutiLevel SubStructuring Tobias Hilgert 
11.06.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Diplomarbeit Martin Mohr 
04.06.08  15:30  Schwarzenbergstrasse 95, Raum 3.053 
Über EigenpaarApproximationen mit (quasi)minimalem Residuum JensPeter M. Zemke 
04.06.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Eigenwertprobleme Elektromagnetischer Felder in Unbeschränkten Gebieten Kemal Yildiztekin 
07.05.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Ein Verfahren zur Simulation von dreidimensionalen Strukturverformungen im Seegang mithilfe modaler Reduktion Boris Dilba 
07.05.08  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Auf Eigenlösern basierende Methoden für regularisierte totale Ausgleichsprobleme Heinrich Voss 
23.04.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Auf Eigenlösern basierende Methoden für regularisierte totale Ausgleichsprobleme Heinrich Voss 
02.04.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
On the multiscale rodlike model in polymeric fluids Hui Zhang, School of Mathematical Sciences, Beijing Normal University, Beijing, 100875, P.R. China We will show the new rigid rodlike model in a polymeric fluid. The constitutive relations considered are motivated by the kinetic theory. The micro equation has five spatial freedom variables, two of them are in the configuration domain and the others are in the macro flow domain. It is obtained the local existence of the solution with large initial data and global existence of the solution with small Deborah and Reynolds constants in periodic domains. For the case of no flow we will give the structure of stationary solutions to the micro equation with MaierSaupe potential on the sphere. The stationary solutions are shown to be necessarily a set of axially symmetric functions, and a complete classification of parameters for phase transitions to these stationary solutions is obtained. It is shown that the number of stationary solutions hinges on whether the potential intensity crosses two critical values 6.731393 and 7.5. Furthermore, we present explicit formulas for all stationary solutions. It is first theoretically proven that there is a hysteresis phenomenon when the nondimensional potential intensity among particles changes. In the weak shear flow, we show that there exist many stable dynamic states: flowaligning, tumbling, logrolling and kayaking, which depend on the initial concentrated orientation of liquid crystal particles. Theoretical analysis is reported the first time that the Kayaking state does not circulate around a fixed direction but the asymmetric axis will periodically change. 
25.03.08  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerical Simulation of a Zero Pressure Gradient Boundary Layer Sergio Hoyas 
25.03.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Applications of the integral transforms to engineering problems Jezabel Perez 
07.03.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Stability Analysis of the Newmark Method Applied to Differential Algebraic Equations (DAEs) Nicolai Rehbein 
07.03.08  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Integratoren für Index2 DAEs aus der Mechanik (Betablocking Techniken) Claus Führer 
05.03.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Detecting hyperbolic and extended strongly hyperbolic matrix polynomials Heinrich Voss 
27.02.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
FluidStruktur Interaktion: Reduktionsansätze für den Hydromassenoperator Alexander Menk 
13.02.08  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Nichtlineare Dynamik verankerter OffshoreStrukturen Katrin Ellermann 
06.02.08  13:00  Schwarzenbergstrasse 95, Raum 3.053 
Solving Trust Region Problems via a Sequence of Linear Eigenproblems Jörg Lampe 
19.12.07  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Varianten des JacobiDavidson Verfahrens für nichtlineare Eigenwertaufgaben Alexander von Graefe 
19.12.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
AMLS with Dynamic Substructuring Tobias Hilgert 
28.11.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Das Kummersche Verfahren für nichtlineare Eigenwertaufgaben Gerhard Unger 
21.11.07  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Possible improvement strategies for AMLS Tobias Hilgert 
21.11.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerical modelling of hyperbolic conservation laws with spatially varying flux functions, Part II Marcus Kraft 
14.11.07  16:00  Schwarzenbergstrasse 95, Raum 3.053 
How to solve RLS and RTLS problems via a sequence of linear Eigenproblems Jörg Lampe 
14.11.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerical modelling of hyperbolic conservation laws with spatially varying flux functions, Part I Arun K.R. 
07.11.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Nonlinear problems in analysis of Krylov subspace methods Zdenek Strakos 
31.10.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Lösung linearer Matrixungleichungen mit Hilfe InteriorPointVerfahren Birgit Stender 
26.10.07  13:00  Schwarzenbergstrasse 95, Raum 3.053 
Anwendung direkter Verfahren der Optimalen Steuerung auf Probleme der Robotik Kemal Yildiztekin 
24.10.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Schallabstrahluhg planarer Strukturen mittels Jinc Funktion Le Nam 
17.10.07  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Bestimmung von Periodizitäten Michael Dudzinski 
10.10.07  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Convergence of aggregation/disaggregation methods in the presence of cyclicity Ivo Marek 
10.10.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
A Discrete RankineHugoniot Solver for Hyperbolic Conservation Laws S.V. Raghurama Rao 
05.10.07  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Grundlagen des QuantenComputing Anna Klich 
22.08.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
folgt noch Bastian Ebeling 
08.08.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Approximation der Hydromassen im Schiffbau Alexander Menk 
25.07.07  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Implementierung eines Algorithmus zur Parameteridentifzierung bei gewöhnlichen Differentialgleichungen mithilfe von SQPVerfahren Katja Wiebracht 
25.07.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Modellierung der Koexistenz einer EColi und Dictyostelium discoidumKokultur Peter Ungemach 
22.06.07  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Characterization of lung nodules in CT images using geometric features Hanno Böttcher 
16.05.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Core problems in linear algebraic systems Chen Ma 
02.05.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Stability and Accuracy of Derivatives with Respect to Parameters of RKMethods Tim Steinhoff 
27.04.07  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Iterative methods for largescale illposed problems Lothar Reichel 
04.04.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Discontinuous Galerkin Verfahren in der Aerodynamik: Höhere Ordnung,Fehlerschätzung und adaptive Gitterverfeinerung Ralf Hartmann 
14.03.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
MLS model reduction for secondorder timeinvariant dynamical systems Frank Blömeling 
14.02.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Vorstellung Promotionsthema Duy Nam Le 
07.02.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Global Convergent Algorithms for the RTLSproblem Jörg Lampe 
31.01.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerische Verfahren für SignoriniKontaktprobleme Markus Stammberger 
24.01.07  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Untersuchung eines LQRReglers und eines ModellPrädiktivenReglers für die Steuerung eines Raumfahrzeugs und eines Kampfjets Janina Zachej 
20.12.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Transient motion in modal coordinates Boris Dilba 
20.12.06  13:00  Schwarzenbergstrasse 95, Raum 3.053 
Stabilisierte Bestimmung der Ableitung bei verrauschten Daten Michael Dudzinski 
13.12.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
On Generalized Schur Algorithms JensPeter M. Zemke 
29.11.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Computer aided detection and characterization of lung nodules in CT images using Support Vector Machines Hanno Böttcher 
29.11.06  13:00  Schwarzenbergstrasse 95, Raum 3.053 
AMLS model order reduction: Projection by Krylov subspaces and second order dynamical systems Frank Blömeling 
22.11.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
NavierStokes Equations in a Time Dependent Domain Anka Zauskova 
08.11.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Kinematical conservation laws  ray theory and applications K.R. Arun 
01.11.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Implementation eines ESDIRK Lösers mit zusätzlicher Ableitung der Lösung nach Parametern und Anfangswert mittels Techniken der automatischen Differentiation Hanno Böttcher 
25.10.06  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Evaluation of Krylov Automated MultiLevel Substructuring in Structural Dynamics Tobias Hilgert 
11.10.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
On a quadratic eigenproblem occurring in regularized total least squares Heinrich Voss 
16.08.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Untersuchung verschiedener Skalierungsvarianten im NichtHermiteschen LanczosAlgorithmus Thomas Radtke 
19.07.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Nonlinear eigenvalue problems in energy band calculation of semiconductor quantum dots Marta Betcke 
05.07.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerical modeling of some geophysical flows Marcus Kraft 
28.06.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerische Methoden für nichtklassische Schockwellen: Entropiesteuerung und LevelSet Methoden Christian Rohde 
24.05.06  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Anwendungen der automatischen Differentiation mit ADMAT/ADMIT/ADiMAT und INTLAB in MATLAB Jan Müller 
10.05.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
On the Comparison of the Finite Volume and the Discontinuous Galerkin Methods Katja Baumbach 
15.03.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Hierarchical substructuring combined with SVDbased model reduction methods Frank Blömeling 
22.02.06  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Eine Toolbox zur Automatischen Differentiation Peter Ungemach 
25.01.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
RankOne Updates in Restarted GMRES Jens Zemke 
11.01.06  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Interne Solitärwellen mit eingeschlossenem Kern: Eine numerische Untersuchung in 3D Moriz Scharpenberg 
12.10.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Modellreduktion für sehr große dünn besetzte Systeme 2 Ordnung mit dem ArnoldiVerfahren Jörg Lampe 
07.09.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Modellreduktion mittels Substrukturierung Frank Blömeling 
24.08.05  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerische Simulation von Quantenpunkten Heinrich Voss 
24.08.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Efficient methods for finding transition states in chemical reactions: comparison of improved dimer method and partitioned rational function optimization method Andreas Heyden 
17.08.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Vom verborgenen Sinn Peter Hildebrandt 
29.06.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Vibroakustische Simulation in der AutomobilEntwicklung Frank Ihlenburg 
15.06.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Berechnung der SEAKopplungsverlustfaktoren in StützenPlattenKopplung Duy Nam Le 
04.05.05  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Constrained Transport Method for the Finite Volume Evolution Galerkin Schemes with Application in Astrophysics Katja Baumbach 
27.04.05  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Model Reduction Methods Using Krylov Subspaces For Solving Rational Eigenvalue Problems Frank Blömeling 
15.12.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
PadeApproximation mit Anwendung bei symmetrischen rationalen Eigenwertproblemen Teil 2 Frank Blömeling 
08.12.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
PadeApproximation mit Anwendung bei symmetrischen rationalen Eigenwertproblemen Teil 1 Frank Blömeling 
01.12.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Modelling of nonNewtonian fluids Jan Cerny 
24.11.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Brände in Tunnelnetzwerken Marcus Kraft 
22.09.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Eine a priori Fehlerschranke für das AMLS Verfahren Voss Heinrich 
15.09.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
From elliptic PDEs to complex approximation Timo Betcke 
01.09.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Berechnung der SEAKopplungsverlustfaktoren mittels Vibrationsrechnungen Duy Nam Le 
14.07.04  16:00  Schwarzenbergstrasse 95, Raum 3.053 
A Modal Approach for the Gyroscopic Quadratic Eigenvalue Problem Kolja Elssel 
14.07.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Finite volume method for the shallow water equations with source terms Zdenek Vlk 
21.04.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Polynomial Approximation in the Complex Plane Timo Betcke 
03.03.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Model reduction methods for solving symmetric rational eigenvalue problems Frank Blömeling 
18.02.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Partitionierung beim Automated Multilevel Substructuring Algorithmus Kolja Elßel 
04.02.04  15:00  Schwarzenbergstrasse 95, Raum 3.053s 
Angepasste KrylovRaum Verfahren für normale Matrizen Jens Zemke 
21.01.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Rationale Eigenwertaufgabe Lada Mazurenko 
07.01.04  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Methoden der Modellreduktion zur Lösung symmetrischer rationaler Eigenwertprobleme Frank Blömeling 
17.12.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Eine Normalform für symplektische Matrizen Sabine Knupfer 
03.12.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Die EvenOdd Zerlegung des charakteristischen Polynomes einer RSPDT Matrix Aleksandra Kostic 
06.11.03  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Ein modaler Ansatz für das Quadratische Eigenwertproblem Kolja Elßel 
29.10.03  17:00  Schwarzenbergstrasse 95, Raum 3.053 
Projektionsverfahren für gyroskopische Eigenwertprobleme Marta Markiewicz 
22.10.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Iterative Projektionsverfahren für nichtlineare Eigenwertaufgaben Heinrich Voß 
18.09.03  14:00  Schwarzenbergstrasse 95, Raum 3.053 
Homotopiemethode für nichtsymmetrische nichtlineare Eigenwertaufgaben Frank Blömeling 
18.09.03  13:00  Schwarzenbergstrasse 95, Raum 3.053 
Die Riccati Methode Christian Schröder 
09.07.03  17:00  Schwarzenbergstrasse 95, Raum 3.053 
Betrachtung des LookAhead Lanczos Algorithmus zur Berechnung betragsmäßig kleiner Eigenwerte Tim Steinhoff 
09.07.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Numerische Modellierung von Systemen hyperbolischer Erhaltungsgleichungen Maria LukacovaMedvidova 
02.07.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
FEModellKorrektur anhand modaler Meßdaten Bastian Ebeling 
30.04.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Ein Beitrag zur Verfolgung von Eigenpfaden mit Anwendungen aus der Strukturdynamik Nils Wagner 
24.04.03  16:00  Schwarzenbergstrasse 95, Raum 3.053 
Passivity Preserving Model Reduction via Interpolation of Spectral Zeros Dan Sorensen 
16.04.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Spectrally good approximations for eigenvalue problems on polygons Timo Betcke 
02.04.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Multilevel Erweiterungen der Komponenten Moden Synthese Kolja Elssel 
12.03.03  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Krylov Methods for Nonlinear Eigenvalue Problems Elias Jarlebring 
18.12.02  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Restarts für GMRES Marta Markiewicz 
11.12.02  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Von Arnoldi über das JacobiDavidson zum Riccati Verfahren für große Eigenwertaufgaben Heinrich Voss 
04.12.02  15:00  Schwarzenbergstrasse 95, Raum 3.053 
ARPACK in Theorie und Praxis Christian Schröder 
20.11.02  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Methoden für nichtlineare Eigenwertaufgabe Lada Mazurenko 
13.11.02  15:00  Schwarzenbergstrasse 95, Raum 3.053 
Die Komponenten Moden Synthese Kolja Elßel 
06.11.02  15:00  Schwarzenbergstrasse 95, Raum 3.053 
ArnoldiTschebyscheff Algorithmus zum Lösen dünn besetzter Eigenwertprobleme Frank Blömeling 
21.08.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Effiziente Methoden für nichtlineare Eigenwertaufgaben Timo Betcke 
03.07.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Inverse Iteration für nichtlineare Eigenwertaufgaben Martin Holters 
26.06.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
MinMax Charakterisierung für nichtlineare Eigenwertaufgaben Teil II Heinrich Voss 
12.06.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Strukturerhaltende Methoden zur Berechnung von Eigenwerten von großen dünnbesetzten schiefhamiltonischen/hamiltonischen Pencils Teil II Sabine Knupfer 
29.05.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Strukturerhaltende Methoden zur Berechnung von Eigenwerten von großen dünnbesetzten schiefhamiltonischen/hamiltonischen Pencils Sabine Knupfer 
08.05.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
GebietszerlegungMultigridSchwarzVerfahren und mehr Reinhard Nabben 
10.04.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
MinMax Charakterisierung für nichtlineare Eigenwertaufgaben Heinrich Voß 
20.03.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
MinMax Charakterisierung für Nichtlineare Eigenwertaufgaben Heinrich Voß 
13.03.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Anwendung der KomponentenModenSynthese zur Berechnung des Dynamischen Verhaltens großer Strukturen Timo Betcke 
27.02.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Eigenwert / Eigenvektor  Relationen Jens Zemke 
13.02.02  10:00  Schwarzenbergstrasse 95, Raum 3.053 
Ein Verfahren der Ordnung (1+sqrt(3))zur Bestimmung des kleinsten Eigenwertes einer Toeplitz Matrix Aleksandra Kostic In this article we compare the set of integer points in the homothetic copy ${n\Pi}$ of a lattice polytope ${\Pi\subseteq{{\mathbb R}}^d}$ with the set of all sums${ x_1+\ldots +xn}$ with ${x_1,\ldots,x_n\in \Pi\cap{{\mathbb Z}}^d}$ and ${n\in{{\mathbb N}}}$. We give conditions on the polytope ${\Pi}$ under which these two sets coincide and we discuss two notions of boundary for subsets of${{{\mathbb Z}}^d}$ or, more generally, subsets of a finitely generated discrete group. 
* Vortrag im Rahmen des Kolloquiums für Angewandte Mathematik