CE Seminar

Together with the Computational Engineering Research Center of the TU Darmstadt a joint seminar with interesting talks in the field of CE is organized in every semester. If you are interested in these seminars and would like to receive invitations please subscribe for the corresponding mailing list.

Forthcoming Talks


Approaching the 50th birthday of the PEEC method: from the early formulation to its current relevance for challenging engineering electromagnetic problems

Prof. Piergiorgio Alotto, PhD, Università di Padova, Italy

3 Feb 2020, 16:15–17:45; Location: S2|17-103

The main focus of this talk is to demonstate how recent developments have extended the applicability and improved the accuracy of the Unstructured Partial Element Equivalent Circuit (PEEC) method. The interest on this subject is spurred by the growing need for fast and efficient numerical methods, which may help engineers during the design and other stages ... [more] »

Category: CE Seminar

Previous Talks


Multigrid methods for structured grids on large-scale supercomputers

Prof. Dr. Matthias Bolten, Bergische Universität Wuppertal

2 Dec 2019, 16:15–17:45; Location: S2|17-103

In many applications in computational science and engineering the solution of a partial differential equation is sought for, often these applications demand a huge amount of compute power or memory, thus requiring the use of supercomputers. For many problems multigrid methods are optimal solvers. By optimality we mean that the convergence rate is bounded ... [more] »

Category: CE Seminar


Multilevel Monte Carlo Methods for the Robust Optimization of Systems Described by Partial Differential Equations

Prof. Stefan Vandewalle, PhD, KU Leuven, Belgium

18 Oct 2019, 13:30–15:00; Location: S2|02-C110

We consider PDE-constrained optimization problems, where the partial differential equation has uncertain coefficients modelled by means of random variables or random fields. The goal of the optimization is to determine an optimum that is satisfactory in a broad parameter range, and as insensitive as possible to parameter uncertainties. First, an overview is ... [more] »

Category: CE Seminar


Towards Flexible Antenna Measurements and Field Transformations in Arbitrary Environments

Prof. Dr. Thomas Eibert, Technical University of Munich, Germany

26 Sep 2019, 14:00–15:30; Location: S2|17-103

Due to the continuously increasing use of electromagnetic services for communications and sensor functionalities, the accurate and reliable characterization of antennas by measurements becomes increasingly important. Traditionally, antenna measurements have been performed in very specialized measurement chambers, which are very expensive and not very ... [more] »

Category: CE Seminar


On high Reynolds number flows, pressure-robustness and high-order methods

Dr. Alexander Linke, WIAS, Berlin

28 Aug 2019, 16:15–17:45; Location: S4|10-1

An improved understanding of the divergence-free constraint for the incompressible Navier-Stokes equations leads to the observation that a semi-norm and corresponding equivalence classes of forces are fundamental for their nonlinear dynamics. The recent concept of pressure-robustness allows to distinguish between space discretisations that discretise these ... [more] »

Category: CE Seminar


Are your scientific applications ready for evolving HPC systems?

Prof. Sunita Chandrasekaran, Ph.D., University of Delaware, Newark, USA

25 Jun 2019, 15:30–17:00; Location: S4|10-1

This talk will present interdisciplinary research that entails the applicability of computer science tools and techniques on real-world scientific applications spanning nuclear physics, molecular dynamics, next-generation sequencing and magnetohydrodynamics (the study of the Sun). As architectures evolve, it is only becoming increasingly challenging for ... [more] »

Category: CE Seminar


Isogeometric Design Optimization of Nonlinear 3D Beam Structures for Multi-material 3D Printing

Prof. Dr. Oliver Weeger, TU Darmstadt

18 Jun 2019, 17:00–18:30; Location: S4|10-1

With the capability to locally control the material composition of a structure, multi-material and multi-method 3D printing technologies provide a new level of design freedom beyond the sole realization of complex topologies. However, the precise design and optimization of spatially varying material compositions within a structure is beyond the capabilities ... [more] »

Category: CE Seminar


From Amdahl’s Law to Memory-Wall: How do we utilize memory systems in the big data era?

Prof. Dr. Xian-He Sun, Illinois Institute of Technology, Chicago, USA

14 Jun 2019, 15:30–17:00; Location: S4|10-1

Amdahl’s law states that parallel processing gain will diminish quickly if problem size does not increase with the computing power. Memory-wall problem clams that data access is the performance bottleneck for data intensive applications; whereas big data applications are all data-centric applications. Data access becomes THE performance concern of ... [more] »

Category: CE Seminar


Similar Size of Slum – An Eigenvalue independent of City, Country and Culture

Prof. Dr.-Ing. Peter Pelz, TU Darmstadt

6 Jun 2019, 17:00–18:30; Location: S4|10-1

In a joint project with DLR, we recently demonstrated that the size of a slum is independent of city, country and culture. The question arises as to why this is so. Natural borders such as coastlines, mountains, rivers or motorways do not serve as reasons. Size must be inherent in migration dynamics. We see migration as a reaction diffusion system by ... [more] »

Category: CE Seminar


Linearization of the nonlinear eigenvalue problem

Prof. Dr. Karl Meerbergen, KU Leuven

27 May 2019, 16:15–17:45; Location: S2|17-103

Everybody is familiar with the concept of eigenvalues of an n times n matrix. In this talk, we consider the nonlinear eigenvalue problem. These are problems for which the eigenvalue parameter appears in a nonlinear way in the equation. The last decade, the number of applications is increasing. In physics, the ... [more] »

Category: CE Seminar


MSO for steel production and manufacturing

Prof. Dr. Dietmar Hömberg, TU Berlin

16 May 2019, 16:15–17:45; Location: S2|17-103

In my presentation I will discuss some results from the European Industrial Doctorate project "MIMESIS – Mathematics and Materials Science for steel production and manufacturing”. The last fifteen years have seen the development of ever more refined high-strength and multiphase steels with purpose designed chemical compositions allowing for ... [more] »

Category: CE Seminar


Unconventional numerical frameworks for the simulation of coupled bulk-interface problems

Prof. Dr. Luca Heltai, SISSA - International School for Advanced Studies, Trieste

6 May 2019, 16:15–17:45; Location: S2|17-103

Fluid-structure interaction problems, interface problems, and partial differential equations with interfaces and/or defects often require the solution of coupled bulk-interface problems. In this talk, I will discuss and analyse some of the techniques that can be used to tackle this class of problems, combining Finite Element Methods, Boundary Element ... [more] »

Category: CE Seminar


Large-Scale Sparse Inverse Covariance Matrix Estimation

Prof. Dr. Matthias Bollhöfer, TU Braunschweig

3 Apr 2019, 10:00–11:30; Location: S4|10-1

The estimation of large sparse inverse covariance matrices is an ubiquitous statistical problem in many application areas such as mathematical finance or geology or many others. Numerical approaches typically rely on the maximum likelihood estimation or its negative log-likelihood function. When the Gaussian mean random field is expected to be sparse, ... [more] »

Category: CE Seminar


High Performance Block Incomplete LU Factorization

Prof. Dr. Matthias Bollhöfer, TU Braunschweig

1 Apr 2019, 16:00–17:30; Location: S4|10-1

Many application problems that lead to solving linear systems make use of preconditioned Krylov subspace solvers to compute their solution. Among the most popular preconditioning approaches are incomplete factorization methods either as single-level approaches or within a multilevel framework. We will present a block incomplete triangular factorization that ... [more] »

Category: CE Seminar


Continuous and Discontinuous Galerkin methods in fluid dynamics with moving geometries

Prof. Dr. Sabine Roller, University of Siegen

5 Feb 2019, 17:00–18:30; Location: S4|10-1

Interaction between structures and the flow around them requires a correct treatment of both of them. If the computational requirements are high, the methods need to be efficient on modern supercomputers that offer a high number of compute nodes and cores. In structural mechanics, often Finite Element (FE) methods are used, while fluid dynamics (especially ... [more] »

Category: CE Seminar


Particle Methods in Bounded Domains

Dr. Matthias Kirchhart, RWTH Aachen

17 Jan 2019, 17:00–18:30; Location: S4|10-314

Particle methods like vortex methods or smoothed particle hydrodynamics are numerical schemes that are ideally suited for convection dominated flow problems. Unlike other mesh-based flow solvers, these methods do not suffer from numerical diffusion and have excellent conservation properties. One of the reasons why particle methods are so rarely used in ... [more] »

Category: CE Seminar


Uncertainty quantification for partial differential equations on random domains

Prof. Dr. Michael Multerer, ICS Institute of Computational Science, Lugano

14 Jan 2019, 16:15–17:45; Location: S2|17-103

The numerical simulation of physical phenomena is very well understood given that the input data are given exactly. However, in practice, the collection of these data is usually subjected to measurement errors. The goal of uncertainty quantification is to assess those errors and their possible impact on simulation results. In this talk, we address different ... [more] »

Category: CE Seminar


A systems guy's view of quantum computing

Prof. Dr. Torsten Hoefler, ETH Zürich

8 Jan 2019, 17:00–18:30; Location: S2|02-C110 (Piloty building)

Abstract: I will provide an introduction to the general concepts of quantum computation and a brief discussion of its strengths and weaknesses from a high-performance computing perspective. The talk is tailored to a computer science audience with basic (popular-science) or no background in quantum mechanics and will focus on the computational aspects. I ... [more] »

Category: CE Seminar


Model Predictive Control for DAEs from an ODE perspective

Jun.-Prof. Dr. Karl Worthmann, TU Ilmenau

26 Nov 2018, 16:15–17:45; Location: S2|17-103

Differential Algebraic Equations (DAEs) combine Ordinary Differential Equations (ODEs) with algebraic constraints. Hence, even for linear systems both the initial condition and the control input cannot be arbitrarily chosen. We present a framework for linear regular systems, which allows to characterise the space of consistent initial conditions and the set ... [more] »

Category: CE Seminar


Exploring Emerging Memory Technologies in Extreme Scale High Performance Computing

Jeffrey S. Vetter, Ph.D., Oak Ridge National Laboratory, USA

6 Nov 2018, 17:00–18:30; Location: S2|02-C205

Abstract: Concerns about energy-efficiency and cost are forcing our community to reexamine system architectures, and, specifically, the memory and storage hierarchy. While memory and storage technologies have remained relatively stable for nearly two decades, new architectural features, such as deep memory hierarchies, non-volatile memory (NVM), and ... [more] »

Category: CE Seminar


Eigenvalue problems for the curl operator, 3D geometric inverse problems and 7D analogies

Dr. Robert Kotiuga, Boston University, USA

29 Oct 2018, 16:15–17:45; Location: S2|17-103

Decades ago, the author obsessed with articulating why topological aspects of 3D finite element (FE) meshes could be deceptively unintuitive, while 2D was so obvious. For EEs, this dichotomy didn’t originate with FE meshes, but is implicit in how nonplanar electronic circuits are communicated. In FE for electromagnetics, the ease with which homology ... [more] »

Category: CE Seminar


On the role of entropy in mathematical modeling, computation and uncertainty quantification

Prof. Dr. Martin Frank, K.I.T. Karlsruhe

25 Oct 2018, 17:00–18:30; Location: S4|10-314

This talk discusses entropy structures for partial differential equations, and how they can be used for efficient HPC computations, and uncertainty quantification. Especially, we recall the entropy-entropy flux structure of hyperbolic conservation laws describing macroscopic flows, and how this structure is inherited from underlying mesoscopic models for ... [more] »

Category: CE Seminar


Asymptotic stability of autonomous (P)DAEs with network structure

Prof. Dr. Caren Tischendorf, Humboldt-Universität zu Berlin

24 Oct 2018, 13:00–14:30; Location: S4|10-314

We analyze autonomous differential algebraic equations (DAEs) with the following particular structure: \[\begin{aligned} x'_1 & = \frac{\text{d}}{\text{d}t} f_1 (y_1) + g_1 (y_1) + r_1,\\ y'_2 & = \frac{\text{d}}{\text{d}t} f_2 (x_2) + g_2 (x_2) + r_2,\\ x_1 & = A_1^\top z,\\ x_2 & = A_2^\top z,\\ 0 & = A_1 y_1 + A_2 y_2, \end{aligned}\] where (\(A_1\), ... [more] »

Category: CE Seminar


Galerkin boundary element methods for electromagnetic resonance problems

Dr. Gerhard Unger, Graz University of Technology

5 Sep 2018, 10:00–11:30; Location: S4|10-314

We consider Galerkin boundary element methods for the approximation of different kinds of electromagnetic resonance problems. Examples are the cavity resonance problem, the scattering resonance problem and the plasmonic resonance problem. An analysis of the used boundary integral formulations and their numerical approximations ispresented in the framework ... [more] »

Category: CE Seminar


Solving Maxwell's equations in time: from Yee splitting to Krylov exponential methods

Mike Botchev, PhD, Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, Moscow

2 Aug 2018, 10:00–11:30; Location: S2|17-103

Solving Maxwell's equations in time domain efficiently is a nontrivial task and represents a fascinating research area. This talk will consist of two parts. In the first part a brief introduction to time integration methods for Maxwell's equations will be given. In particular, we will discuss (1) why the celebrated Yee scheme (often used in Finite ... [more] »

Category: CE Seminar


Modeling the impact of stenting of aortic coarctations upon left ventricular load

Dr. Elias Karabelas, University of Graz

28 Jun 2018, 17:00–18:30; Location: S4|10-314

Hemodynamic models of blood flow in the left ventricle (LV) and aorta are important tools for analyzing the mechanistic links between myocardial deformation and flow patterns in human hearts. Typically, computational fluid dynamics (CFD) models driven by image-based kinematic models are employed aiming to predict the acute response to an intervention. While ... [more] »

Category: CE Seminar


Quasi-Newton – A Universal Approach for Coupled Problems and Optimization

Prof. Dr. Miriam Mehl, University of Stuttgart

20 Jun 2018, 17:00–18:30; Location: S4|10-314

Quasi-Newton methods are used in many fields to solve non-linear equations without explicitly known derivatives. This is the case, e.g., in coupled multi-physics applications such as fluid-structure interactions where we combine several independent solvers in a partitioned approach coupled simulation environment. To do so, we have to solve a (in general ... [more] »

Category: CE Seminar


Spatially dispersive metals for nanophotonics-about DGTD, model calibration and experimental evidence

M.Sc. Nikolai Schmitt, INRIA Sophia Antipolis, France

18 Jun 2018, 16:15–17:45; Location: S2|17-103

In nanoplasmonics, most metal devices are sub wavelength. This leads to geometrical sizes comparable to the skin-depth of electromagnetic waves at optical frequencies. Appropriate material models of the metallic bulk are hence indispensable. Additionally, if the effective wavelength of the plasmon (a wave that relies on oscillations of the free electrons ... [more] »

Category: CE Seminar


Massively Parallel Mixed Integer Programs (MIP) Solving: Towards Harnessing over a Million CPU Cores to Solve a Single MIP on Supercomputers

Dr. Yuji Shinano, Zuse-Institute Berlin

14 Jun 2018, 17:00–18:30; Location: S4|10-314

Mixed integer programming (MIP) problem is a general form to model combinatorial optimization problems and has many industrial applications. The performance of MIP solvers, software packages to solve MIPs, has improved tremendously in the last two decades and these solvers have been used to solve many real-word problems. However, against the backdrop of ... [more] »

Category: CE Seminar


An introduction to energy-based modeling of lumped- and distributed-parameter coupled problems

M.Sc. Michal Maciejewski, CERN, Switzerland

11 Jun 2018, 16:15–17:45; Location: S2|17-103

Power-conservation is a fundamental property of mathematical models describing physical phenomena. The modeling consistency can be ensured if each subsystem fulfills this requirement. Next step in modeling is to ensure, that the combination of these subsystems still maintains this property. To this end, we employ bond graph and port-Hamiltonian modeling. ... [more] »

Category: CE Seminar


Nonsmooth Optimization via Successive Abs-Linearization

Prof. Andreas Griewank, Yachaytech University, Ecuador

4 Jun 2018, 17:00–18:30; Location: S4|10-314

In finite dimensions abs-linearization of a function defined by smooth elementals  and abs, min, and max yields a piecewise linear continuous approximation function  at a given development point. The error between this local model and the underlying piecewise smooth function is uniformly of second order in the distance to the development ... [more] »

Category: CE Seminar


Network of elastic rods in relation to elastic plate and shell models

MSc Matko Ljulj, University of Zagreb, Kroatia

17 May 2018, 17:00–18:30; Location: S4|10-314

In this talk the linear elastic rod (1D) model and linear elastic shell (2D) model will be shown. Since numerical solving of 3D linear elasticity PDE on thin domains is challenging and gives incorrect results due to using dense meshes, low-dimensional models show great advantage. After that, we will show applications of those concepts in modelling ... [more] »

Category: CE Seminar


Multiscale simulation of slow-fast high-dimensional stochastic processes: methods and applications

Prof. Dr. Giovanni Samaey, KU Leuven, Belgium

14 May 2018, 16:15–17:45; Location: S2|17-103

We present a framework for the design, analysis and application of computational multiscale methods for slow-fast high-dimensional stochastic processes. We call these processes "microscopic'', and assume existence of an approximate "macroscopic'' model that captures the slow behaviour of a selected set of macroscopic state variables. The ... [more] »

Category: CE Seminar


Application of the ACA to problems in electromagnetic scattering

Dr. Lucy Weggler, Biotronik SE & Co KG, Berlin

7 May 2018, 16:15–17:45; Location: S2|17-103

Because of quadratic memory requirements classical boundary element realisations are applicable only for a rather moderate number N of boundary elements. A possible solution to this problem is to take advantage of the good approximation properties of the boundary element matrices. One established approximation scheme is called the adaptive cross ... [more] »

Category: CE Seminar


Asymptotic modeling of the wave-propagation over acoustic liners

Dr. Adrien Semin, TU Berlin/ BTU Cottbus

3 May 2018, 17:00–18:30; Location: S4|10-314

We will consider the acoustic wave propagation in a channel separated from a chamber by a thin periodic layer. This model stand for microperforated absorbers which are used to supress reflections from walls. Due to the smallness of the periodicity a direct numerical simulation, e.g. with the finite element method (FEM), is only possible for very large ... [more] »

Category: CE Seminar


HPC Programming Models and Tools: Programmer’s Expectations

Dr. Christian Terboven, RWTH Aachen University

18 Apr 2018, 16:30–18:00; Location: S1|22-403

Parallel programming for HPC systems is a challenging task, and will remain so. Although we have found that certain programming models and development approaches are more productive than others, there is no single best tool for the job. In this talk, I will present our performance analysis and engineering workflow and and our findings on the programming ... [more] »

Category: CE Seminar


A High Order Method for the Approximation of Integrals over Implicitly Defined Hypersurfaces

Dr. Holger Heumann, CASTOR, INRIA, Sophia Antipolis, France

15 Mar 2018, 17:00–18:30; Location: S4|10-1

We present a novel method to compute approximations of integrals over implicitly defined hypersurfaces. Control applications for thermonuclear fusion reactors, such as the upcoming ITER tokamak, are the initial motivation of this research work. The new method is based on a weak formulation that uses the coarea formula to circumvent an explicit integration ... [more] »

Category: CE Seminar


Quasistatic Field Models and Recent Developments in their Numerical Simulation Methods

Prof. Dr. Markus Clemens, Bergische Universität Wuppertal

5 Feb 2018, 16:15–17:45; Location: S2|17-103

Quasistatic electromagnetic field models are considered for situations, where the shortest wave length of a problem exceeds the spatial dimensions of the problem by at least one order of magnitude. A taxonomy of such quasistatic field models distinguishes between the electro-quasistatic, the magneto-quasistic and the so-called Darwin field models. These ... [more] »

Category: CE Seminar


Sparse optimal control of PDEs with uncertain coefficients

Prof. Dr. Georg Stadler, New York University

16 Jan 2018, 17:00–18:30; Location: S4|10-1

We study sparse solutions of optimal control problems governed by elliptic PDEs with uncertain coefficients. Sparsity of controls is achieved by incorporating the \(L^1\)-norm of the mean of the pointwise squared controls in the objective.  Two optimal control formulations are proposed, one where the solution is a deterministic control that optimizes ... [more] »

Category: CE Seminar


Waveform Relaxation on Circuit Differential-Algebraic Equations: A Topological Convergence Criterion

Jonas Pade, M.Sc., Humboldt-University of Berlin

18 Dec 2017, 16:15–17:45; Location: S2|17-103

While waveform relaxation methods converge for coupled ODE systems, they may suffer from instabilities for coupled differential-algebraic equations (DAEs). Whereas several convergence criteria are known for index-1 DAEs, we present here a convergence criterion for quasilinear index-2 DAEs for the first time. It applies to systems of coupled ODE/circuit ... [more] »

Category: CE Seminar


Mobile technology for production-ready high-performance computing systems: The path of the Mont-Blanc project

Filipo Mantovani, Barcelona Supercomputing Center

23 Oct 2017, 16:30–18:00; Location: S2|02-C110

Since 2011 the EU Mont-Blanc project pushes the development of ARM-based compute platforms, following the vision of leveraging the fast growing market of mobile technology for performing scientific computation. The process started almost 5 years ago with the development of prototypes based on Android dev-kits and is now evolving beyond the research project, ... [more] »

Category: CE Seminar


Coupled Simulations of Electric Arcs for Switching Devices with MpCCI and ANSYS

Pascal Bayrasy, Fraunhofer-Institute for Algorithms and Scientific Computing SCAI, St. Augustin, Germany

6 Oct 2017, 14:00–15:30; Location: S2|17-103

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Category: CE Seminar


Bunch trains in the Linac Coherent Light Source

Dr. Karl Bane, SLAC National Accelerator Laboratory, USA

11 Sep 2017, 16:30–18:00; Location: S2|17-103

The Linac Coherent Light Source is a linac-based, X-ray free electron laser (FEL) at the SLAC National Accelerator Laboratory. It accelerates single bunches up to 4­--13 GeV before sending them to the undulator for lasing. A project is underway to run the LCLS bunches in trains, with up to initially four and later eight bunches in a train. Bunch trains will ... [more] »

Category: CE Seminar


Towards pressure-robust mixed methods for the incompressible Navier-Stokes equations

Dr. Alexander Linke, Weierstrass Institute for Applied Analysis and Stochastics, Berlin

20 Jul 2017, 17:00–18:30; Location: S4|10-1

For more than thirty years it was thought that the efficient construction of pressure-robust mixed methods for the incompressible Navier-Stokes equations, whose velocity error is pressure-independent, was practically impossible. However, a novel, quite universal construction approach shows that it is indeed rather easy to construct pressure-robust mixed ... [more] »

Category: CE Seminar


Efficient calculation of spectral bounds for Hessian matrices on hyperrectangles

Prof. Dr.-Ing. Martin Mönnigmann, Ruhr-Universität Bochum

18 Jul 2017, 17:00–18:30; Location: S4|10-1

The presentation summarizes progress made over the past few years in the calculation of spectral bounds of interval Hessian matrices. Spectral bounds of this type play an important role in global optimization algorithms. They can be used, for example, to detect if a given optimization problem is convex, or to generate a convex relaxation in case it is not. ... [more] »

Category: CE Seminar


Bayesian subset simulation

Prof. Julien Bect, CentraleSupélec, France

17 Jul 2017, 16:15–17:45; Location: S2|17-103

The numerical computation of small probabilities of failure for a system is a notoriously difficult problem, and the Subset Simulation algorithm of Au & Beck (Prob. Eng . Mech., 2001) has become one of the most popular method to solve it. Subset simulation has been shown to provide significant savings in the number of evaluations of the performance ... [more] »

Category: CE Seminar


Tools and methods to support the correctness of parallel programs

Prof. Dr. Matthias S. Müller, RWTH Aachen University

10 Jul 2017, 16:30–18:00; Location: S2|02-C110

Parallel programming for large scale computer architectures is a complex and error-prone task. Automatic tools can assist application developers in the detection and removal of such errors. This talk will present the scalable runtime tool MUST, the methods behind the tool (graph analysis, push down automaton) and the limitations that ... [more] »

Category: CE Seminar


Sensitivity-Based Topology and Shape Optimization with Application to Electrical Machines

Dr. Peter Gangl, RICAM, Johann Radon Institute for Computational and Applied Mathematics, Linz

3 Jul 2017, 16:15–17:45; Location: S2|17-103

We investigate methods of topology and shape optimization for an optimal design problem from electrical engineering which is constrained by the quasilinear PDE of two-dimensional magnetostatics. We derive the topological derivative of the objective function, i.e., its sensitivity with respect to a topological perturbation of the domain, and compare it to ... [more] »

Category: CE Seminar


Integer Programming for Layout Problems

Prof. Dr. Peter Wonka, KAUST, Thuwal (Saudi Arabia​)

30 Jun 2017, 10:00–11:30; Location: S3|05-074 (Fraunhofer IGD)

In this talk, we will give an introduction to Integer Programming (IP) and show how we used IP in recent research projects. The projects range from problem formulations in visualization to urban modeling. The talk will focus mainly on the modeling side of integer programming, i.e. how to formulate a given problem as integer ... [more] »

Category: CE Seminar


Logic & Proofs for Cyber-Physical Systems

Prof. Dr. André Platzer, Carnegie Mellon University, Pittsburgh, PA (USA)

26 Jun 2017, 15:00–16:15; Location: S2|02-B002 (Piloty building)

Cyber-physical systems (CPS) combine cyber aspects such as communication and computer control with physical aspects such as movement in space, which arise frequently in many safety-critical application domains, including aviation, automotive, railway, and robotics. But how can we ensure that these systems are guaranteed to meet their design goals, e.g., ... [more] »

Category: CE Seminar


The inclusion of adaptivity concepts in the context of POD model order reduction

Carmen Gräßle, University of Hamburg

8 Jun 2017, 17:00–18:30; Location: S4|10-1

The basic idea of model order reduction utilizing proper orthogonal decomposition (POD-MOR) consists in replacing a high-dimensional problem by a low-dimensional POD approximation with the aim to save computational times and storage capacity while preserving a good approximation quality. Following the idea of Sirovich (1987), the POD surrogate models are ... [more] »

Category: CE Seminar


Numerical Solution of Reactive Transport Equations by Discontinuous Galerkin Method

Prof. Dr. Bülent Karasözen, Middle East Technical University, Ankara (Turkey)

1 Jun 2017, 17:00–18:30; Location: S4|10-1

Protection and sustainable management of water resources is one of the key problems in environmental engineering. In this aspect, accurate modeling and simulating coupled ground and surface water flows is a necessity. Chemically reactive components such as dissolved minerals, colloids, or contaminants are transported by advection and diffusion over long ... [more] »

Category: CE Seminar


Through the Looking-Glass: From Performance Observation to Dynamic Adaptation

Prof. Dr. Allen Malony, University of Oregon, Eugene, OR (USA)

29 May 2017, 14:00–15:30; Location: S4|14-5.3.01

Since the beginning of "high-performance" parallel computing, observing and analyzing performance for purposes of finding bottlenecks and identifying opportunities for improvement has been at the heart of delivering the performance potential of next-generation scalable systems. Interestingly, it is the ever-changing parallel computing landscape ... [more] »

Category: CE Seminar


Optical and Electronic Properties of Nanohelices

Prof. Dr. Vojislav Krstić, Friedrich-Alexander-Universität Erlangen-Nürnberg

22 May 2017, 16:15–17:45; Location: S2|17-103

Nanohelices with pitch and diameter as characteristic dimensions of the order of 100 nm are formidable systems to investigate optical and electronic properties of matter on the nanoscale. Their unique helical structure on the nanoscale is the source of a range of unconventional properties. In the present work, first the production process of the ... [more] »

Category: CE Seminar


Non-overlapping domain decomposition formulations for the wave equation

Dr. Clemens Pechstein, CST AG

24 Apr 2017, 16:15–17:45; Location: S2|17-103

To date, there is a large literature on non-overlapping domain decomposition (DD) methods for acoustic and electromagnetic wave problems. For some of these methods, the domain decomposition is tightly coupled to the formulation and makes it difficult to understand. In this talk (based on joint work with Timo Euler, CST AG), we develop a unified DD ... [more] »

Category: CE Seminar


Numerical approximation of charged particle motion in magnetic quadrupoles

Abele Simona and Prof. Luca Bonaventura, Politecnico di Milano

13 Mar 2017, 16:15–17:45; Location: S2|17-103

We present some attempts at improving the accuracy and efficiency of the reference numerical methods presently employed to model charged particle motion in magnetic quadrupoles. We first introduce the standard technique used to reconstruct the quadrupole magnetic vector potential, based on general solutions of the Laplace equation in cylindric coordinates. ... [more] »

Category: CE Seminar


A Study of Dynamic Loop Scheduling Algorithms on Modern Manycore Architectures

Prof. Dr. Florina Ciorba, Universität Basel

20 Feb 2017, 16:30–18:00; Location: S2|02-C110

High performance computing (HPC) systems are nowadays large, consist of diverse components, and exhibit massive parallelism. Exploiting the available hardware parallelism is notoriously challenging, in part due to difficulty in exposing and expressing parallelism in the computational applications. Loops are considered the main source of parallelism in most ... [more] »

Category: CE Seminar


NVM and HPC – Is there a use case?

Prof. Dr. André Brinkmann, Johannes Gutenberg Universität Mainz

13 Feb 2017, 16:30–18:00; Location: S2|02-C120

Parallel file systems (PFS) have been developed to support typical HPC applications, where most file system operations include reading or writing huge chunks of data, which can be easily striped over the storage backend. New data-intensive applications will change these patterns and small random I/Os will occur more frequently in HPC, missing the sweet-spot ... [more] »

Category: CE Seminar


Parallel-in-Time Integration with PFASST

Dr. Robert Speck, Forschungszentrum Juelich GmbH

30 Jan 2017, 16:15–17:45; Location: S2|17-103

For time-dependent partial differential equations, parallel-in-time integration using the "parallel full approximation scheme in space and time" (PFASST) is a promising way to accelerate existing space-parallel approaches beyond their scaling limits. Inspired by the classical Parareal method and non-linear multigrid ideas, PFASST allows to integrate ... [more] »

Category: CE Seminar


Numerical Simulations of Insect Flight in Heavy Turbulence

Thomas Engels, Ph.D., TU Berlin / École Normale Supérieure Paris

12 Jan 2017, 17:00–18:30; Location: S4|10-1

The aerodynamics of flying insects is a field of research currently receiving much attention from a broad, interdisciplinary community of researchers. Their motivation ranges from the design of bio-inspired robots to fundamental questions in biology and fluid mechanics. Insects are known to produce a surprising amount of force, using comparatively small ... [more] »

Category: CE Seminar


Partial differential-algebraic equations from a systems theoretic perspective

Prof. Dr. Timo Reis, University of Hamburg

14 Nov 2016, 16:15–17:45; Location: S2|17-103

We consider linear and time-invariant partial differential-algebraic equations and show that these can be represented as differential-algebraic equations on infinite-dimensional Banach spaces. We will discuss solution theory, decoupling and control by means of several examples in flow and electric circuit theory. [more] »

Category: CE Seminar


Modeling and Simulation of Generalized Stefan Problems with Applications in Planetary Exploration

Dr. Julia Kowalski, RWTH Aachen

8 Nov 2016, 17:00–18:30; Location: S4|10-1

We will discuss the modelling and simulation of generalized Stefan problems to describe phase-change processes in water ice. An idealized mathematical system for the classical Stefan problem consists of two free-boundary second-order partial differential equations for both the solid, and the liquid phase. The system is closed by assuming local energy ... [more] »

Category: CE Seminar


Amorphous Data-parallelism

Prof. Keshav Pingali, University of Texas, Austin

22 Sep 2016, 10:00–11:00; Location: S2|02-C110

Although data-parallelism is ubiquitous in high-performance computing (HPC) algorithms, many algorithms in other areas such as graph analytics, machine learning, and VLSI placement and routing exhibit a more complex kind of parallelism that called "amorphous data-parallelism." In this talk, I describe a simple programming model called the ... [more] »

Category: CE Seminar


Demonstration of Energy-Chirp Control in Relativistic Electron Bunches at LCLS Using a Corrugated Structure

Dr. Karl Bane, SLAC National Accelerator Laboratory (CA, USA)

12 Sep 2016, 16:15–17:45; Location: S2|17-103

Abstract: An experimental study is presented that uses a corrugated structure as a passive “dechirper”— i.e. as a device for removing energy chirp — in a high energy (4.4 ‐ 13.3 GeV) electron beam at the Linac Coherent Light Source (LCLS) at SLAC. Time‐resolved measurements of both longitudinal and transverse wakefields of the device are presented and ... [more] »

Category: CE Seminar


Simulation of electrical machines – A FEM-BEM coupling scheme

Dr. Lars Kielhorn, TailSiT GmbH, Graz (Austria)

25 Jul 2016, 16:15–17:45; Location: S4|10-314

Electrical machines commonly consist of moving and stationary parts, e.g., an electric motor features a rotor and a stator. If volume based numerical schemes such as the Finite Element Method (FEM) are applied the electromagnetic simulation of such devices is a challenging task since the variation of the geometrical configuration needs to be incorporated ... [more] »

Category: CE Seminar


Scientific Benchmarking of Parallel Computing Systems

Prof. Dr. Torsten Hoefler, ETH Zurich

12 Jul 2016, 16:00–17:30; Location: S4|10-1

Measuring and reporting performance of parallel computers constitutes the basis for scientific advancement of high-performance computing (HPC). Most scientific reports show performance improvements of new techniques and are thus obliged to ensure reproducibility or at least interpretability. Our investigation of a stratified sample of 120 papers across ... [more] »

Category: CE Seminar


Simulation of wave propagation problems for automated characterization of material parameters and defects

Steven Vanderkerckhove, KU Leuven

11 Jul 2016, 16:15–17:45; Location: S2|17-103

Non-destructive testing and evaluation (NDT&E) by ultrasonic (or electromagnetic) waves is important for the identification of material parameters, for quality assurance and life-time control. Many NDT&E techniques and procedures are available, but generally rely on a considerable amount of a priori knowledge and expertise which are often expensive ... [more] »

Category: CE Seminar


A new implementation of the MMPDE moving mesh method and applications

Prof. Weizhang Huang, Ph.D., University of Kansas, Lawrence (USA)

11 Jul 2016, 14:00–15:30; Location: S4|10-314

The MMPDE moving mesh method is a dynamic mesh adaptation method for use in the numerical solution of partial differential equations. It employs a partial differential equation (MMPDE) to move the mesh nodes continuously in time and orderly in space while adapting to evolving features in the solution of the underlying problem. The MMPDE is formulated as the ... [more] »

Category: CE Seminar


Oscillation in a posteriori error estimation

Prof. Dr. Andreas Veeser, Università degli Studi di Milano

7 Jul 2016, 17:00–18:30; Location: S4|10-314

The goal of an a posteriori error analysis for an approximate PDE solution is to establish the equivalence of error and a posteriori estimator. Unfortunately, this equivalence is often only up to so- called oscillation terms. In this talk we shall clarify the reasons for the presence of oscillation and point out shortcomings of common oscillation terms. ... [more] »

Category: CE Seminar


Advances in Massively Parallel Electromagnetic Simulation Suite ACE3P

Dr. Oleksiy Kononenko, SLAC National Accelerator Laboratory/Stanford University

1 Jul 2016, 10:00–11:30; Location: S2|17-114

ACE3P is a 3D massively parallel electromagnetic simulation suite that has been developed at SLAC National Accelerator Laboratory for the past decades. This set of codes is based on the finite-element method so that geometries of complex structures can be represented with high fidelity through conformal grids, and high solution accuracies can be obtained ... [more] »

Category: CE Seminar


Nanoelectronic coupled problem solutions: methods and applications

Dr. E. Jan W. ter Maten, Bergische Universität Wuppertal

27 Jun 2016, 16:15–17:45; Location: S2|17-103

The project nanoCOPS is a collaborative research project within the FP7-ICT research program funded by the European Union. The consortium comprises experts in mathematics and electrical engineering from six universities (BU Wuppertal, HU Berlin, Brno UT, TU Darmstadt, FH Oberösterreich Hagenberg im Mühlkreis, EMAU Greifswald), a research institute ... [more] »

Category: CE Seminar


Do You Know What Your I/O is Doing?

Prof. William Gropp, University of Illinois, Urbana-Champaign (USA)

24 Jun 2016, 10:30–12:00; Location: S2|02-C120

Even though supercomputers are typically described in terms of their floating point performance, science applications also need significant I/O performance for all parts of the science workflow. This ranges from reading input data, to writing simulation output, to conducting analysis across years of simulation data. This talk presents recent data on the use ... [more] »

Category: CE Seminar


Finite Element Method on uniform and adaptive polygonal and polyhedral meshes

Prof. Dr. Sergej Rjasanow, Universität des Saarlandes

30 May 2016, 16:15–17:45; Location: S2|17-103

In the development of numerical methods to solve boundary value problems the requirement of flexible mesh handling gains more and more importance. The BEM-based finite element method [1] is one of the new promising strategies which yield conforming approximations on polygonal and polyhedral meshes, respectively. This flexibility is obtained by special ... [more] »

Category: CE Seminar


Multi-Trace Boundary Element Methods for Scattering

Prof. Dr. Ralf Hiptmaier, ETH Zurich

9 May 2016, 16:15–17:45; Location: S2|17-103

We consider the scattering of acoustic or electromagnetic waves at a penetrable object composed of different homogeneous materials, that is, the material coefficients are supposed to be piecewise constant in sub-domains. This makes possible to recast the problem into boundary integral equations posed on the interfaces. Those can be discretized by means of ... [more] »

Category: CE Seminar


Sweeping Preconditioning, Source Transfer and optimized Schwarz Methods

Dr. Martin Gander, Université de Genève

2 May 2016, 16:15–17:45; Location: S2|17-103

Absorbing boundary conditions and perfectly matched layers are not only useful for the truncation of computational domains, they can also be very effectively used to obtain preconditioners. This was first realized in the context of Schwarz methods about 20 years ago, in the research group around Frederic Nataf and Laurence Halpern, and led to the class of ... [more] »

Category: CE Seminar


Numerical models of the subsurface – applications and challenges

Prof. Dr. Andreas Henk, TU Darmstadt

26 Apr 2016, 17:00–18:30; Location: S4|10-1

The subsurface holds numerous resources ranging from groundwater and minerals to energy (e.g., geothermal, hydrocarbons), but it can also act as storage site for CO2 and nuclear waste. Any optimal and safe utilization of the deep subsurface requires a thorough ... [more] »

Category: CE Seminar


Microstructural Aspects of Flow Simulation in Biomedical and Production Engineering Applications

Prof. Marek Behr, Ph.D., RWTH Aachen University

21 Apr 2016, 10:30–12:00; Location: S4|10-314

Many incompressible flows of engineering interest involve fluids that are governed by complex constitutive relations. For viscoelastic fluids in particular, the advective nature of the constitutive equation requires numerical stabilization. Moreover, the use of three distinct variable fields means that two separate compatibility conditions must be ... [more] »

Category: CE Seminar


An isogeometric boundary element method for electromagnetic analysis

Dr. Robert Simpson, University of Glasgow

19 Apr 2016, 10:00–11:30; Location: S2|17-103

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Category: CE Seminar


An asynchronous One-shot method for HPC

Dr. Torsten Bosse, Argonne National Laboratory, U.S.A.

31 Mar 2016, 17:00–18:30; Location: S4|10-1

The One-shot method for design optimization problems has been successfully implemented for various physical applications. To this end, a slowly convergent primal fixed-point iteration of the underlying state equation is augmented by an adjoint iteration and a corresponding preconditioned design update. Besides a suitable choice for the ... [more] »

Category: CE Seminar


Thread and Data Mapping in Shared Memory Architectures

Matthias Diener, PhD, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre (Brazil)

25 Feb 2016, 17:00–18:30; Location: S4|10-1

Modern parallel architectures have a complex memory hierarchy, which consists of several cache levels and multiple memory controllers per system. In such architectures, the performance of memory accesses from a thread depends highly on which core the thread is executing and on which cache/memory controller the data is located. Therefore, ... [more] »

Category: CE Seminar


Asynchronous numerical scheme for modeling microwave/plasma couplings

Dr. Ronan Perrussel, Université de Toulouse

15 Feb 2016, 16:15–17:45; Location: S2|17-103

We present an asynchronous method for the explicit integration of multiscale partial differential equations with a particular focus on microwave-plasma interactions. This method is restricted by a local CFL condition rather than the traditional global CFL condition. Moreover, contrary to other local time-stepping (LTS) methods, the asynchronous algorithm ... [more] »

Category: CE Seminar


Computational topology and hybrid high order methods for computational electromagnetics

Prof. Dr. Ruben Specogna, Università di Udine

8 Feb 2016, 16:15–17:45; Location: S2|17-103

The efficient numerical solution of eddy current problems, whether formulated with differential or integral techniques, requires some topological pre-processing. Kotiuga, in his pioneering papers in the eighties, showed that computational topology is something that one should get familiar with when bumps into problems related with the design of ... [more] »

Category: CE Seminar


Finite element error estimates for elliptic Dirichlet-boundary control problems with pointwise state constraints

Prof. Dr. Ira Neitzel, University of Bonn

21 Jan 2016, 17:30–19:00; Location: S4|10-1

PDE constrained optimal control problems with pointwise state constraints are known to cause certain theoretical and numerical difficulties. In this talk, we are concerned with an elliptic Dirichlet boundary control problem with low regularity of the state variable. After discussing first order optimality conditions in KKT-form, we will focus on presenting ... [more] »

Category: CE Seminar


Efficient strategies to reduce the memory footprint and CPU usage in parallel Large Eddy Simulations of turbulent combustion with large flamelet-based chemistry tables

Prof. Dr. Christian Hasse, Technische Universität Bergakademie Freiberg

15 Dec 2015, 17:00–18:30; Location: S4|10-1

Fast chemical reactions in combustion take place in thin layers, which are usually called flamelets. The flamelet regime is the most prominent one in technical applications. Thus, flamelet-based models have been used very successfully and are actively developed for the simulation of turbulent combustion by the scientific community. ... [more] »

Category: CE Seminar


Hierarchische Matrizen: ein universelles Konzept zur Behandlung elektromagnetischer Probleme

Prof. Dr. Mario Bebendorf, University of Bayreuth

27 Nov 2015, 15:30–17:00; Location: S2|17-103

Der Vortrag behandelt die schnelle numerische Lösung elliptischer Randwertprobleme mittels hierarchischer Matrizen. Im ersten Teil des Vortrags werden nicht-lokale Operatoren, die beispielsweise durch Diskretisierung von Integraloperatoren entstehen, untersucht. Die auftretenden Systemmatrizen sind vollbesetzt, so dass bereits ihre Generierung eine ... [more] »

Category: CE Seminar


Adjoint Methods for Efficient Optimization and Control in CFD and CAA

Prof. Dr. Nicolas Gauger, TU Kaiserslautern

5 Nov 2015, 17:00–18:30; Location: S4|10-1

For efficient detailed aerodynamic or aeroacoustic designs as well as optimal active flow control, the use of adjoint approaches is an essential ingredient. Using adjoint methods, one is able to compute the gradients needed for sensitivity-based optimization and control methods, with a numerical effort independent from the number of ... [more] »

Category: CE Seminar


Model-Order Reduction for Nonlinear Eddy Current Problems via Quadratic-Bilinear Modeling

Dipl.-Ing. Daniel Klis, Universität des Saarlandes

2 Nov 2015, 16:15–17:45; Location: S2|17-103

The finite-element time-domain simulation of nonlinear systems requires the iterative solution of a large, sparse system of equations at every time-step. Model-order reduction is a powerful tool for reducing the computational effort for this task. State-of-the-art methods compute an affine approximation to the nonlinearity. In contrast, the ... [more] »

Category: CE Seminar


Performance Analysis for the Exascale Era: From Measurements to Insights

Dr. Martin Schulz, Lawrence Livermore National Laboratory, USA

17 Jul 2015, 14:00–15:30; Location: S4|10-1

Abstract With rising system and application complexity, performance analysis is more important, but also more difficult than ever. Traditional performance are capable of measuring large volumes of performance data that can help with this process, but the interpretation of this data is becoming more and more the bottleneck. Simply comparing ... [more] »

Category: CE Seminar


Development of a discontinuous Galerkin method for variable viscosity Stokes problems: Applications in geodynamics

Dominic E. Charrier, ETH Zurich

16 Jul 2015, 10:00–11:30; Location: S4|10-314

Traditionally in the geodynamics community, staggered grid finite difference schemes and mixed Finite Elements (FE) have been utilised to discretize the variable viscosity Stokes problem. While these methods are considered to be sufficiently robust and accurate for a wide range of variable viscosity problems they tend to have inf-sup constants which are ... [more] »

Category: CE Seminar


Software-Defined & High-Fidelity Visualization

Dr. Johannes Guenther, Intel

15 Jul 2015, 14:00–15:30; Location: S4|10-1

Abstract Supercomputers help to analyze huge data sets and to simulate complex theories in different science domains. Today, the results of these analyses and simulations are visualized using GPUs in workstations or small, dedicated visualization clusters. However, visualization on GPUs becomes harder and harder due to the ever increasing data size ... [more] »

Category: CE Seminar


A Plane Wave Virtual Element Method for the Helmholtz Problem

Prof. Ilaria Perugia, University of Vienna

6 Jul 2015, 17:00–18:30; Location: S4|10-1

The Virtual Element Method (VEM) is a generalisation of the finite element method recently introduced by Beirao da Veiga, Brezzi, Cangiani, Manzini, Marini and Russo in 2013, which takes inspiration from modern mimetic finite difference schemes, and allows to use very general polygonal/polyhedral meshes.  This talk is concerned with a new method based ... [more] »

Category: CE Seminar


High Performance Scientific Computing @cs.pub.ro

Prof. Emil Slusanschi, University Politehnica of Bucharest, Bucharest

24 Jun 2015, 17:00–18:30; Location: S4|10-314

In this talk we will give an overview of the High Performance Scientific Computing activities that are currently taking place at the Computer Science and Engineering of the University Politehnica of Bucharest, Romania. In particular, we will present applications from the areas of: meteorology, aerospace, ... [more] »

Category: CE Seminar


Problem-suited numerical methods for some complex flows

Prof. Dr. Maria Lukacova, University of Mainz

23 Jun 2015, 13:00–14:30; Location: L1|01-K328

In this talk we will present efficient numerical schemes for two classes of complex flows: i) Fluid-Structure interaction problems with application in hemodynamics and ii) Singular limit flows with application in meteorology. We derive problem-suited finite volume and/or Discontinous Galerkin approximations and analyse the scheme with respect to ... [more] »

Category: CE Seminar


ADiJaC – Automatic Differentiation of Java Classfiles

Prof. Emil Slusanschi, University Politehnica of Bucharest, Bucharest

15 Jun 2015, 17:00–18:30; Location: S4|10-314

In this talk we discuss the current design and implementation of ADiJaC, an automatic differentiation tool for Java classfiles. ADiJaC uses source code transformation to generate derivative codes in both the forward and the reverse modes of automatic differentiation. We describe the overall architecture of the tool, and ... [more] »

Category: CE Seminar


H-matrix accelerated second moment analysis for potentials with rough correlation

Jürgen Dölz, University of Basel

2 Jun 2015, 17:00–18:30; Location: S4|10-1

After a brief introduction to the boundary element method and H-matrices we consider the efficient solution of strongly elliptic potential problems with stochastic Dirichlet data. The computation of the solution’s two-point correlation is well understood if the two-point correlation of the Dirichlet data is known and sufficiently smooth. Unfortunately, the ... [more] »

Category: CE Seminar


Energy stable integration of Allen-Cahn and Cahn-Hilliard equations

Prof. Dr. Bülent Karasözen, Middle East Technical University, Ankara (Turkey)

23 Apr 2015, 16:00–17:30; Location: S4|10-314

We consider Allen-Cahn and Cahn-Hilliard equations as phase fi eld models with constant and variable mobility. Both equations are discretized in space using symmetric interior penalty discontinuous Galerkin (SIPG) fi nite elements. Time discretization is performed by the energy stable average vector field (AVF) method for gradient systems like Allen-Cahn ... [more] »

Category: CE Seminar


Fast Galerkin Methods for Parabolic Boundary Integral Equations

Prof. Johannes Tausch, Southern Methodist University Dallas, Texas (USA)

9 Mar 2015, 17:00–18:30; Location: S4|10-1

The boundary element method is a widely used technique for solving problems governed by elliptic PDEs. On the other hand, the application of integral equation methods to time dependent problems is much less developed and a topic of current research. Time dependence is reflected in the fact that boundary integral operators involve integrals over time in ... [more] »

Category: CE Seminar


Non-Uniform Rational B-Splines in Fluid Flow Simulations

Dr.-Ing. Stefanie Elgeti, RWTH Aachen

9 Feb 2015, 16:15–17:45; Location: S2|17-103

Two important influences on the accuracy of simulation results are the approximation properties of the numerical scheme with respect to, on the one hand, the unknown solution, and on the other hand, the geometry representation. The latter aspect poses a particular challenge in the context of deforming computational domains. These deformations can either be ... [more] »

Category: CE Seminar


Multirate Simulation by the MPDE technique for Radio Frequency Circuits

FH-Prof. Dr.-Ing. habil. Hans Georg Brachtendorf, Upper Austria University of Applied Sciences (FHO), Hagenberg

12 Jan 2015, 16:15–17:45; Location: S2|17-103

In this talk we give an overview of the FHO activities in the fp-7 research projects ICESTARS, nanoCOPS, the ENIAC project ARTEMOS, and the Austrian basic research project "Spline/wavelet based methods in circuit simulation". In Radio Frequency (RF) circuits one observes slowly varying envelope or baseband signals modulated by a carrier signal at ... [more] »

Category: CE Seminar


Towards Non-Smooth Efficient Modeling of Large Data

Prof. Hamid Krim, North Carolina State University, Raleigh (U.S.A.)

2 Dec 2014, 14:30–15:30; Location: S3|06-257

High dimensional data exhibit distinct properties compared to its low dimensional counterpart; this causes a common performance decrease and a formidable computational cost increase of traditional approaches. Novel methodologies are therefore needed to characterize data in high dimensional spaces. Considering the parsimonious degrees of freedom of ... [more] »

Category: CE Seminar


The Use of Nonlinear Structures for Augmented Performance in Smart Material Systems

Andres F. Arrieta, PhD, ETH Zurich

2 Dec 2014, 14:00–15:30; Location: S4|10-414

Physical phenomena in most engineering fields and applications are inherently nonlinear. Yet, most established engineering design tools have been developed for idealised linear systems. In particular, structural nonlinearity in engineering design has been traditionally associated with problems and loss of functionality, often at the expense of overdesign ... [more] »

Category: CE Seminar


Electromagnetic fields, Lorentz force effects and fast current surges in microelectronic protection devices

Dr. Wim Schoenmaker, Magwel NV (Leuven, Belgium)

1 Dec 2014, 16:15–17:45; Location: S2|17-103

Electrostatic discharge (ESD) is a serious design concern in microelectronic device fabrication and usage. Current spikes of the order of amperes active over a time lap of a nanosec need to be screened off from the core circuits by ESD protection devices. On-chip silicon controlled rectifiers are used for this purpose. The fast transient effect lead to ... [more] »

Category: CE Seminar


Equivalent polynomial quadrature for XFEM - like enriched formulations

Prof. Giulio Ventura, Politecnico di Torino, Italy

30 Oct 2014, 17:00–18:30; Location: S4|10-1

The powerful properties of formulations enriched with discontinuous or singular functions like XFEM, GFEM and SDA is the ability to represent features independently of the mesh structure. However, a problematic point in their practical implementation is given by the quadrature to compute the element stiffness. In fact, especially in 3D, the element are ... [more] »

Category: CE Seminar


Exploiting Sparsity in Derivative Computations

Prof. Dr. H. Martin Bücker, Friedrich Schiller University Jena

28 Oct 2014, 17:00–18:30; Location: S4|10-1

Derivatives of mathematical functions are needed in various areas of computational engineering. Examples include the solution of nonlinear systems of equations and inverse problems. When the function is given in the form of a computer program, automatic differentiation (AD) enters the picture. In this set of powerful techniques, ... [more] »

Category: CE Seminar


Block preconditioners for problems in magma dynamics

Dr. Garth Wells, Cambridge University

25 Sep 2014, 16:30–18:00; Location: S4|10-1

Simulations of realistic Earth science problems are characterised by massive scale and coupled sets of equations. In the case of problems such as subduction zones, geometric effects are central. These features demand numerical methods and software libraries that are flexible and high performance, and the deployment of scalable linear solvers. In working ... [more] »

Category: CE Seminar


On Stability of Stationary Points in MPCCs

Michal Červinka, Ph.D., Charles University, Prague

1 Sep 2014, 16:15–18:00; Location: S4|10-1

We consider parameterized mathematical programs with constraints governed by the generalized nonlinear complementarity problem and with additional non-equilibrial constraints. We study a local behavior of stationarity maps that assign the respective C- or M-stationarity points of the problem to the parameter. We provide criteria for the isolated calmness ... [more] »

Category: CE Seminar


Reduced Basis Methods for Parametric Problems

Jun.-Prof. Bernard Haasdonk, University of Stuttgart

28 Jul 2014, 16:15–17:45; Location: S2|17-103

In this presentation we will address different aspects concerning Reduced Basis (RB) methods for parametric partial differential equations (PDEs). This class of model reduction techniques enables rapid solution of parametric problems in the real-time or many-query context and has gained quite some interest and wide development over the last decade After ... [more] »

Category: CE Seminar


Accelerated Observers in Electrodynamics - What can they do for you?

Prof. Stefan Kurz, Robert Bosch GmbH and Tampere University of Technology

21 Jul 2014, 16:15–17:45; Location: S2|17-103

We introduce a relativistic splitting structure as a means to map fields and equations of electromagnetism from curved four-dimensional spacetime to three-dimensional observer's space. We focus on a minimal set of mathematical structures that are directly motivated by the language of the physical theory. Space-time, world-lines, time translation, space ... [more] »

Category: CE Seminar


Exploitation of Structure and Parallelism in ADOL-C

Prof. Andrea Walther, University of Paderborn

16 Jul 2014, 17:00–18:30; Location: S4|10-314

For numerous applications the exploitation of structure and/or parallelism  is indispensable for the efficient computation of derivatives and also for the design of new solution approaches. We discuss  recent developments integrated in the software package ADOL-C for the algorithmic differentiation of C and C++ codes to utilize ... [more] »

Category: CE Seminar


Domain decomposition techniques for highfrequency harmonic wave problems

Prof. Christophe Geuzaine, University of Liège

14 Jul 2014, 16:15–17:45; Location: S2|17-103

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Category: CE Seminar


Fast Moment Method for Beam Line Simulations

Dr. Toon Roggen, CERN

7 Jul 2014, 16:15–17:45; Location: S2|17-103

Particle accelerators are among the most complicated contemporary devices and consist of a large number of components, each with a specific function. All components need to be tuned with respect to each other to achieve the prescribed particle beam characteristics. Seemingly small deviations from an individual component's design specifications may induce ... [more] »

Category: CE Seminar


The Power of Trefftz Methods: Difference Schemes, Absorbing Conditions and Metamaterials

Prof. Igor Tsukerman, The University of Akron, U.S.A.

4 Jul 2014, 11:00–12:30; Location: S4|10-314

In mathematical physics and engineering, Trefftz approximations by definition involve functions that satisfy the underlying differential equation of the problem (as well as the interface boundary conditions). Examples include harmonic polynomials for the Laplace equation; plane waves, cylindrical or spherical harmonics for wave problems; exponential ... [more] »

Category: CE Seminar


A multigrid approach to optimal control of obstacle problems

Dr. Michelle Vallejos, TU Chemnitz

3 Jul 2014, 17:00–18:30; Location: S4|10-1

An optimal control problem governed by an elliptic variational inequality is considered. We focus on the optimal control of the obstacle problem, which is a prototypical example of variational inequalities of the first kind. A robust multigrid strategy for solving obstacle problems will be presented. This algorithm is then extended in order to apply ... [more] »

Category: CE Seminar


High-performance Computing for Flows in Porous Media

Prof. Peter Bastian, Ruprecht-Karls-Universität Heidelberg, Interdisziplinäres Zentrum für Wissenschaftliches Rechnen

26 Jun 2014, 16:30–18:00; Location: S4|10-1

Simulation of flow and transport processes in porous media provides a formidable challenge and application field for high-performance computing. Relevant continuum-scale models include partial differential equations of elliptic, parabolic and hyperbolic type which are coupled through highly nonlinear coefficient functions. The multi-scale character and ... [more] »

Category: CE Seminar


Automation of Industrial Design Processes by Using Optimization and Process Integration

Prof. Dr. Dieter Bestle, Brandenburgische Technische Universität Cottbus

22 May 2014, 15:30–17:00; Location: S4|10-314

In industrial product development, design decisions are mostly based on intensive parameter studies combined with expert knowledge, where in case of complex technical systems like aero engines typically several experts from different departments have to be involved. However, typically each department uses its own analysis programs with its own data ... [more] »

Category: CE Seminar


Applications in Computational Design & Analysis

Dr. Jason Wu, The Boeing Company, Seattle, U.S.A.

20 May 2014, 17:00–18:30; Location: S4|10-1

Wavy plies or wrinkles in carbon fiber reinforced plastic (CFRP) composite structures can result in performance knockdowns. The performance impact of the ply distortion can depend on many factors, but two commonly desired parameters are the wrinkle height and width. An ultrasonic B-scan of the wrinkle can reveal the ply distortion; however, visual ... [more] »

Category: CE Seminar


Innovative compatible discretization techniques for Partial Differential Equations

Prof. Annalisa Buffa, Institute of Applied Mathematics and Information Technology, Pavia

19 May 2014, 10:00–11:30; Location: S4|10-1

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Category: CE Seminar


Coupling of Finite and Boundary element Methods: Applications and Recent Developments

Dr. Günther Of, TU Graz

28 Apr 2014, 17:00–18:30; Location: S4|10-1

The coupling and finite and boundary element methods has been attractive for the numerical solution of boundary value problems of second order partial differential equations for decades. In particular, so-called non-symmetric formulations have been very popular in applications for a long time. Originally, the results on the stability of related ... [more] »

Category: CE Seminar


Mathematical Modeling of Magnetostrictive Materials

Mané Harutyunyan and Bernd Simeon, Felix-Klein-Center for Mathematics, University of Kaiserslautern

28 Apr 2014, 16:15; Location: S2|17/103, Schlossgartenstrasse 8

Magnetostrictive materials belong to the large class of Smart Materials, which change their mechanical behavior and properties in response to the application of an external field, such as temperatur or magnetic field. Particularly magnetostrictive elastomers, composites consisting of ferrous particles dispersed in an elastomeric matrix, can exhibit large ... [more] »

Category: CE Seminar


Software Tool Support for Discrete Adjoint Methods - A Discrete Adjoint Version of OpenFOAM

Uwe Naumann, Software and Tools for Computational Engineering (STCE), RWTH AAchen

28 Apr 2014, 15:30–17:00; Location: S4|10-1

This talk will focus on issues arising in the context of the generation of a discrete adjoint version of OpenFOAM using algorithmic differentiation (AD). The existing discrete adjoint version of OpenFOAM is based on our AD tool dco/c++ (derivate code by overloading in C++). It uses the adjoint MPI (AMPI) library for adjoint message passing. Prototyped at ... [more] »

Category: CE Seminar


Generating performance bounds from source code

Dr. Krishna Narayanan, Mathematics and Computer Science Division, Argonne National Lab, USA

22 Apr 2014, 15:45–17:15; Location: S4|10-1

In this talk he will discuss the source analysis tool PBound, that estimates the upper performance bounds of C and Fortran applications. Built on the ROSE compiler framework, PBound generates parametrized expressions for different types of memory accesses and integer and floating-point computations. Additionally, PBound uses application reuse distance ... [more] »

Category: CE Seminar


Uncertainty quantification in a computationally optimised volume conductor model for deep brain stimulation

Dr.-Ing. Christian Schmidt, University of Rostock

17 Feb 2014, 16:15–17:00; Location: S2|17-103

Deep brain stimulation (DBS) has evolved as a widely employed procedure to treat the symptoms of motor skill disorders such as Parkinson’s disease, essential tremor and dystonia. Although successfully employed across various clinical fields, the fundamental mechanisms of action of DBS remain uncertain. Starting in the last decade, many computational models ... [more] »

Category: CE Seminar


Discrete adjoints for MPI-parallelized C++ models with an application to the NASA/JPL Ice Sheet System Model

Dr. Jean Utke, Argonne National Laboratory, U.S.A.

6 Feb 2014, 17:00–18:30; Location: S4|10-1

Computing discrete adjoints by algorithmic differentiation (AD) enables gradient-based optimization for high-dimensional problems. First, I introduce AD principles and implementation options (i.e. operator overloading) relevant to models written in C++ and parallelized with MPI. Then I present our ongoing work with the Ice Sheet System Model (ISSM), ... [more] »

Category: CE Seminar


Quantification of uncertainties in low frequency computational electromagnetics: from theory to applications: from theory to applications

Prof. Stéphane Clénet, L2EP, Arts et Métiers ParisTech, Lille

27 Jan 2014, 16:15–17:45; Location: S2|17-103

In electrical engineering, the input data (dimensions, material properties, external inputs, etc.) of models are often assumed to be known exactly. The models as well as their outputs are then deterministic. However, in the real world, the input data are often stochastic. The dimensions of any device are known within a given uncertainty (tolerance) due to ... [more] »

Category: CE Seminar


Noise reduction strategies for particle in cell simulations of tokamaks and stellarators

Prof. Dr. Eric Sonnendrücker, Max-Planck-Institut für Plasmaphysik, Garching

13 Jan 2014, 16:15–17:45; Location: S2|17-103

Simulation of micro-turbulence in magnetic fusion plasmas either in stellarators or in tokamaks can be realised efficiently with Particle In Cell methods (PIC) provided some efficient noise reduction is achieved so that noise levels are well below signal levels. This can be achieved using a control variate method using a stochastic process associated with ... [more] »

Category: CE Seminar


Optimal Control of a Free Boundary Problem with Surface Tension Effects

Prof. Harbir Antil, George Mason University, Fairfax (USA)

17 Dec 2013, 11:00–12:30; Location: S4|10-1

We consider a PDE constrained optimization problem governed by a free boundary problem. The state system is based on coupling the Laplace equation in the bulk with a Young-Laplace equation on the free boundary to account for surface tension, as proposed by P. Saavedra and L.R. Scott. This amounts to solving a second order system both in the bulk and on the ... [more] »

Category: CE Seminar


Using Automated Performance Modeling to Find Scalability Bugs in Complex Codes

Prof. Dr. Felix Wolf, FZ Jülich

3 Dec 2013, 10:00–11:30; Location: S4|10-1

Many parallel applications suffer from latent performance limitations that may prevent them from scaling to larger machine sizes. Often, such scalability bugs manifest themselves only when an attempt to scale the code is actually being made - a point where remediation can be difficult. However, creating analytical performance models that would allow such ... [more] »

Category: CE Seminar


Tackling the Software Stack for Heterogeneous Multi-Processors: a balancing act between work-load and memory organisation

Prof. Dr. Sven-Bodo Scholz, Heriot-Watt University, Edinburgh

2 Dec 2013, 14:00–15:30; Location: S4|10-1

In today's economic climate, time to market, or more generally time to solution, is critical. At the same time, mainstream hardware does not only become massively parallel, it also becomes much more diverse: Graphics Processors (GPUs), large vector machines such as Intel's Xeon-Phi, and even programmable hardware in the form of FPGAs find an increasing ... [more] »

Category: CE Seminar


High Productivity Parallel Programming with SAC and S-Net: from Language Design to Compilers and Runtime Systems

Prof. Dr. Clemens Grelck, University of Amsterdam

2 Dec 2013, 10:00–11:30; Location: S4|10-1

Parallel Programming has long closely been tied to high performance computing. Today's ubiquity of multi-core chip architectures radically changes this: parallel programming moves from a niche market into the main stream of computing. At the same time, hardware becomes more and more diverse: varying numbers of cores with complex cache hierarchies, ... [more] »

Category: CE Seminar


Two-scale simulation of electromagnetic devices using harmonic and pulse-width-modulation time-domain basis functions

Prof. Johan Gyselinck, Université libre de Bruxelles

18 Nov 2013, 16:15–17:45; Location: S2|17-103

 [more] »

Category: CE Seminar


Accelerators for Technical Computing?

Dieter an Mey, RWTH Aachen

13 Nov 2013, 16:30–18:00; Location: S4|10-1

“More bang for the buck” is the promise of deploying accelerators attached to commodity host processors for technical computing. Since NVIDIA introduced the CUDA programming model in 2006, more and more programmers started using graphics processors for technical computing. Amazing success stories reported high speed-up rates of applications accelerated by ... [more] »

Category: CE Seminar


IsoGeometric analysis methods for multiphysics problems

Carlo de Falco, Ph.D., Politecnico di Milano CEN Centro di Nano Medicina, Milan

4 Nov 2013, 16:15–17:45; Location: S2|17-103

The concept of Isogeometric Analysis (IGA) was introduced by Hughes with the aim of bridging the gap between computer aided design (CAD) and the finite element method. This aim is pursued by adopting the same Non Uniform Rational B-Spline (NURBS) basis functions to construct both trial and test spaces in the discrete variational formulation of differential ... [more] »

Category: CE Seminar


Firedrake and (adjoint) FEniCS: is automatic parallel simulation a mythical beast?

Dr. David Ham, Imperial College London

1 Nov 2013, 13:00–14:30; Location: S4|10-1

Pushing back the frontiers of simulation technology in science and engineering becomes ever more complex. Better simulations of more realistic systems require greater complexity in both equations and numerics, while the shift from increasing processor speed to massive fine-scale parallelism radically increases the complexity of the software implementation. ... [more] »

Category: CE Seminar


Sound and Vibration from Friction between Soft Materials under Light Loads

Prof. Adnan Akay, BILKENT University, Ankara (Turkey)

24 Oct 2013, 17:00–18:30; Location: S4|10-1

Understanding the properties and consequences of friction under light normal loads is fundamental to further advancing areas such as tactile sensing, haptic systems used in robotic gripping of sensitive objects, and characterization of products that range from the softness of fabrics to effects of surfactants, such as lotions, on skin. In tactile sensing, ... [more] »

Category: CE Seminar


First principles applied to submersible maneuvering

Prof. Dr. Hernani Brinati, University of Sao Paulo, Brazil

22 Oct 2013, 17:00–18:30; Location: S4|10-1

An analytical-numerical model based on first principles for representation of the motions of a submarine in the horizontal and in the vertical plane is presented. The model is implemented through computational algebra, being its parameters expressed as function of the main dimensions and form coefficients of the hull and its appendices, ... [more] »

Category: CE Seminar


Wang Tilings in Synthesis of Microstructure Informed Enrichment Functions With Application in Trefftz Method

Jan Novak, Ph.D., Czech Technical University in Prague

21 Oct 2013, 16:15–17:45; Location: S2|17-103

The sustainable environmental tendencies lead to a highly optimized design of majority of consumer products. In Materials Engineering, this is mirrored by a race towards miniaturization and top product performance. A potential success is seen in a detailed understanding and incorporation of characteristic physical processes taking place at materials ... [more] »

Category: CE Seminar


Performance Modeling for Performance Autotuning

Dr. Paul Hovland, Argonne National Laboratory, U.S.A.

30 Sep 2013, 17:00–18:30; Location: S4|10-1

We describe our efforts in performance modeling in the context of automatic performance tuning.  We consider analytic models constructed through source code analysis, semi-analytic models constructed with a combination of source code analysis and empirical measurement, and fully empirical models.  We describe several uses ... [more] »

Category: CE Seminar


Numerical simulation of Bingham fluids by semismooth Newton methods: a general survey

Prof. Sergio Gonzalez, Ph.D., Escuela Politécnica Nacional Quito (Ecuador)

26 Sep 2013, 17:00–18:30; Location: S4|10-1

In this talk we show a new approach to the numerical simulation of Bingham fluids, based on semismooth Newton methods. From pipe flow to thermally convective flow, we present the challenges and the modeling and numerical tools to overcome such issues. [more] »

Category: CE Seminar


Adaptive Asynchronous Parallel Calculations at Petascale Using Uintah

Prof. Dr. Martin Berzins, University of Utah

17 Sep 2013, 17:00–18:30; Location: S4|10-1

The past, present and future scalability of the Uintah Software framework is considered with the intention of describing a successful approach to large scale parallelism. Uintah allows the solution of large scale fluid-structure interaction problems through the use of fluid flow solvers coupled with particle-finite element based solid methods. In addition ... [more] »

Category: CE Seminar


An Efficient Layerwise Finite Element Model for Active Vibration Control of Piezolaminated Composite Shells considering Strong Electric Field Nonlinearity

Prof. Santosh Kapuria, Indian Institute of Technology Delhi

18 Jul 2013, 17:00–18:30; Location: S4|10-1

In this work, we present a computationally efficient finite element (FE) model for statics, dynamics and vibration control of smart composite and sandwich shallow shells integrated with piezoelectric sensors and actuators, considering their nonlinear characteristics under strong electric field. The nonlinearity is modeled using the rotationally invariant ... [more] »

Category: CE Seminar


Finite Element Based Deformable Object Tracking from a Single Viewpoint

Jochen Lang, Ph.D., University of Ottawa

10 Jul 2013, 14:00–15:30; Location: S3|05-074

In this talk, I will present our recent work on robustly tracking objects that deform due to an external applied force. The geometry of the object is reconstructed over time based on noisy observations from a single viewpoint. A template mesh of the object in its rest-state is fit to observations in a nonlinear optimization. We use a redundant ... [more] »

Category: CE Seminar


MPI + MPI: a new hybrid approach to parallel programming with MPI plus shared memory

Prof. Torsten Höfler, ETH Zurich

9 Jul 2013, 17:00–18:30; Location: S4|10-1

Hybrid parallel programming with the message passing interface (MPI) for internode communication in conjunction with a shared-memory programming model to manage intranode parallelism has become a dominant approach to scalable parallel programming. While this model provides a great deal of flexibility and performance potential, it saddles programmers with ... [more] »

Category: CE Seminar


Modeling flows in complex geometries using volume penalization: analysis of the penalized Stokes operator and applications to the Navier-Stokes equations

Prof. Kai Schneider, University Aix-Marseille

4 Jul 2013, 17:00–18:30; Location: S4|10-1

Penalization approaches are nowadays commonly employed to solve boundary or initial-boundary value problems. They consist in embedding the original, possibly complex spatial domain inside a bigger domain having a simpler geometry, for example a torus, while keeping the boundary conditions approximately enforced thanks to new terms that are added to the ... [more] »

Category: CE Seminar


Unstructured high order discretization schemes: an enabling technology for reliable LES in an industrial context

Dr. Koen Hillewaert, Cenaero - Simulation technologies for Aeronautics, Gosselies (Belgium)

25 Jun 2013, 17:00–18:30; Location: S4|10-1

The simulation of turbulent flows by the Large Eddy Simulation (LES) or Direct Numerical Simulation (DNS) approaches requires extremely low numerical dispersion and dissipation. Finite Element-like high-order methods such as the discontinuous Galerkin (DGM), spectral difference (SDM) and spectral element methods (SEM), ... have attracted considerable ... [more] »

Category: CE Seminar


Emotion Recognition, 3-D Obstacle Detection, and Human Activity Monitoring

Prof. Salim Bouzerdoum, University of Wollongong, Australia

21 Jun 2013, 10:00–11:30; Location: S3|06-257

In this seminar, we will discuss a number of recent advances in visual pattern recognition and image classification. In particular, we will present three applications of visual pattern recognition: to emotion recognition, 3-D vision for assistive navigation, and human activity monitoring using Doppler radar. One of the challenges of visual pattern ... [more] »

Category: CE Seminar


Adaptive Discontinuous Galerkin Methods for nonlinear Diffusion-Convection-Reaction Models

Prof. Dr. Bülent Karasözen, Middle East Technical University, Ankara (Turkey)

20 Jun 2013, 17:00–18:30; Location: S4|10-1

Many engineering problems such as chemical reaction processes, population dynamics, ground water contamination are governed by coupled diffusion-convection-reaction partial differential equations (PDEs) with nonlinear source or sink terms. Nonlinear transport systems are typically convection and/or reaction dominated with characteristic solutions possessing ... [more] »

Category: CE Seminar


Simulation and Optimal Control of Time-Periodic PDE Problems

Prof. Dr. Ulrich Langer, Johannes Kepler University, Linz

19 Jun 2013, 17:15–18:45; Location: S4|10-1

This talk is provided together with the department of mathematics. [more] »

Category: CE Seminar


Highly accurate impedance boundary conditions for thin conducting sheets

Dr. Kersten Schmidt, TU Berlin

17 Jun 2013, 10:30–12:00; Location: S2|17-103

Shielding sheets are commonly used in the protection of electronic devices. With their large aspect ratios they become a serious issue for the direct application of the finite element method, as many small cells are required to resolve the sheets, as well as the direct application of the boundary element method (BEM) due to the occuring almost singular ... [more] »

Category: CE Seminar


Mathematische Bildverarbeitung mittels Compressed Sensing

Prof. Dr. Gitta Kutyniok, TU Berlin

29 May 2013, 17:15–18:45; Location: S2|14-24

Compressed Sensing is a novel research area, which was introduced in 2006, and since then has already become a key concept in various areas of applied mathematics. It predicts that high-dimensional signals, which allow a sparse representation by a suitable basis/frame, can be recovered from highly incomplete linear measurements by using efficient ... [more] »

Category: CE Seminar


Finite-Element Simulation of Time-Harmonic Electromagnetic Fields

Prof. Dr. Romanus Dyczij-Edlinger, Universität des Saarlandes, Saarbrücken

27 May 2013, 16:15–17:45; Location: S2|17-103

A broad class of structures in electronics and high-frequency engineering exhibits linear time-invariant system properties. It ranges from antennas and filters through wiring structures of integrated circuits to the cavities of linear accelerators and the elementary cells of meta-materials. Such structures constitute distributed-parameter systems of high ... [more] »

Category: CE Seminar


Unveiling some Mysteries of Application Performance on Multi-/Manycore Processors

Prof. Dr. Gerhard Wellein, Friedrich-Alexander-University Erlangen

23 May 2013, 17:00–18:30; Location: S4|10-1

The multicore trend has brought forth a variety of computer architectures suitable for numerical simulation. Nowadays there is no longer a single driving force for numerical performance. To make efficient use of the hardware the programmer must address multiple architectural features at the same time – otherwise he will face a performance ... [more] »

Category: CE Seminar


Particles – bridging the gap between solids and fluids

Prof. Dr. Peter Eberhard, University of Stuttgart

14 May 2013, 17:00–18:30; Location: S4|10-1

First, an overview about the research done at the institute will be given to set the framework why we are interested in the computationally so demanding particle methods. These methods have recently emerged as engineering tools that can be widely used in many different disciplines. Due to their meshless nature, they are especially well suited for problems ... [more] »

Category: CE Seminar


Fast Solvers for Emerging Power Systems

Prof. Dr. Domenico Lahaye, TU Delft

15 Apr 2013, 16:15–17:45; Location: S2|17-103

National power grids are currently evolving from static entities, producing mainly a uni-directional flow from generation to loads, to more dynamic and decentralized structures. These emerging power systems should accommodate the local generation by renewable sources and peak demands of electrical vehicle charging. The cross-border interconnection of power ... [more] »

Category: CE Seminar


Structural optimization of asymmetric brake rotors for the separation of their eigenfrequencies

Andreas Wagner, TU Darmstadt

4 Apr 2013, 17:00; Location: S4|10-1

Suppression of brake squeal has received a lot of attention by engineering researchers in the past. It is widely accepted in the scientific community that the self-excited vibrations induced by the frictional contact between brake disc and brake pad are the main cause of brake squeal. Presently, a variety of methods are being discussed to avoid squealing, ... [more] »

Category: CE Seminar


Efficient method to model the fluid lag in fluid-driven crack simulations

Prof. Yongxing Shen, Universitat Politecnica de Catalunya, Barcelona

7 Feb 2013, 17:00; Location: S4|10-1

We study the fluid-structure interaction encountered in hydraulic fracturing, a technique used by the oil and gas industry. Simulating this process needs to take into account the interaction between a fracturing solid and the fluid flow in the crack. In particular, with the possible presence of a fluid lag, the evolving fluid front inside the crack and the ... [more] »

Category: CE Seminar


Functional A Posteriori Error Estimates for Static Maxwell Type Problems

Prof. Dr. Dirk Pauly, University Duisburg-Essen

6 Dec 2012, 17:00; Location: S4|10-1

This talk is concerned with the derivation of computable and guaranteed upper and lower bounds of the di erence between the exact and the approximate solution of boundary value problems for static Maxwell type equations. Our analysis is based upon purely functional argumentation and does not attract speci c properties of an approximation method. Therefore, ... [more] »

Category: CE Seminar


Nitsche-based finite element methods for the Stokes problem on cut and composite meshes – analysis, implementation and applications

Andre Massing, PhD, Simula Research Laboratory AS, Fornebu (Norway)

22 Nov 2012, 17:00; Location: S4|10-1

Multi-domain and multi-physics problems with moving interfaces and parameter studies with changing geometric domains can be severely limited by the use of conforming meshes when complex geometries in three spatial dimensions are involved. To overcome these limitations, several fixed-grid methods based on XFEM, Nitsche's method and related approaches have ... [more] »

Category: CE Seminar


High-Quality Software Development in Academia: (Un-)Feasible?

Dr.-Ing. Klaus Iglberger, University Erlangen-Nürnberg

8 Nov 2012, 17:00; Location: S4|10-1

Software development in academia is subject to a set of special circumstances that make the development of sustainable, maintainable, and high-quality software particularly difficult. In this talk I address these problems, explain why academia might be facing substantials problems in years to come, but also why the creation of ... [more] »

Category: CE Seminar


Uncertainty Quantification in Flow-Structures Interaction

Prof. Fernando A. Rochinha, Federal University of Rio de Janeiro, Brazil

11 Oct 2012, 17:00; Location: S4|10-1

Consistently replacing prototypes or physical experiments by computations has been pursued within the Engineering and Applied Science community in the last decades, to a large extent due to the impressive computer power available nowadays. But the use of computer simulations as an effective tool still faces conceptual and technical challenges. Chief among ... [more] »

Category: CE Seminar


Fluid-Structure Interactions in Turbines

Prof. Romuald Rzadkowski, PhD, Polish Academy of Sciences, Gdańsk

20 Sep 2012, 17:00; Location: S4|10-1

A three-dimensional nonlinear time-marching method and numerical analysis for aeroelastic behaviour of oscillating blade row has been presented. The approach is based on the solution of the coupled fluid-structure problem in which the aerodynamic and structural  equations are integrated simultaneously in time. Thus providing the correct formulation of ... [more] »

Category: CE Seminar


preCICE - a multiphysics coupling environment for flexible coupling of black-box solvers

M.Sc. Bernhard Gatzhammer, TU München

9 Aug 2012, 10:00; Location: S4|10-1

 [more] »

Category: CE Seminar


Productivity and Performance with Multi-Core Programming

Christian Terboven, Center for Computing and Communication, RWTH Aachen University

4 Jul 2012, 17:00; Location: S4|10-1

The multicore era has led to a renaissance for shared memory parallel programming models. Moreover, the introduction of Task-level parallelization raises the level of abstraction compared to thread-centric expression of parallelism. However, shared memory parallel applications may exhibit poor performance on NUMA systems if  ... [more] »

Category: CE Seminar


Recent Advances in PETSc Scalable Solvers

Dr. Lois Curfman McInnes, Argonne National Laboratory, U.S.A.

2 Jul 2012, 14:00; Location: S4|10-1

We will discuss recent advances in the Portable, Extensible Toolkit for Scientific computing (PETSc) that enable application scientists to develop composable linear, nonlinear, and timestepping solvers for multiphysics and multilevel methods on emerging extreme-scale architectures.  Examples of usage include lithosphere dynamics, ... [more] »

Category: CE Seminar


Autotuning: search, specialization, and multiple objectives

Dr. Paul Hovland, Argonne National Laboratory, U.S.A.

6 Jun 2012, 17:00; Location: S4|10-1

We describe recent and ongoing work in the area of automatic performance tuning. By employing specialization, we can develop tuned variants for the most common usage scenarios in a given application. By posing the empirical search problem as a mathematical optimization problem, we can draw upon the large body of research in derivative free optimization ... [more] »

Category: CE Seminar


The GSI Green-IT Cube, a highly energy efficient data center

Prof. Dr. Volker Lindenstruth, Goethe-Universität, Frankfurt/Main

31 May 2012, 17:00; Location: S4|10-1

At GSI a new data center is being built, which sets new standards in energy efficiency and cost. The computer racks are cooled directly with heat exchangers and mounted on a steel structure much like a high rack warehouse. This architecture enables power densities exceeding 20 kW/m² and floor or 100 kW/m². The entire data center will support computers up to ... [more] »

Category: CE Seminar


Substrate integrated waveguide integration with active components

Farzaneh Taringou, University of Victoria, Kanada

14 May 2012, 09:00; Location: S2|17-114

Substrate integrated waveguide (SIW) technology has been largely explored as a low-cost low-profile transmission line in passive microwave and millimeter circuits and devices. Yet,little research has been done to assess SIW performance in integration with active elements, e.g. Power Amplifier (PA) and Low Noise Amplifier (LNA). The ... [more] »

Category: CE Seminar


Control of fluid flow using electromagnetic body forces

Dr. Thomas Albrecht, Forschungszentrum Dresden Rossendorf

3 May 2012, 17:00; Location: S4|10-1

In many engineering applications, the way natural fluid flows behave leaves some room for improvement. While geometric optimizations, such as streamlined shapes, require no additional energy input, they might not always be possible, feasible, or sufficient.

Another option is active flow control, where a suitable actuator more or less ... [more] »

Category: CE Seminar


Design by Transformation - Application to Dense Linear Algebra Libraries

Prof. Dr. Robert van de Geijn, University of Texas at Austin, U.S.A.

17 Apr 2012, 17:00; Location: S4|10-1

The FLAME project has yielded modern alternatives to LAPACK and related efforts. An attractive feature of this work is the complete vertical integration of the entire software stack, starting with low level kernels that support the BLAS and finishing with a new distributed memory library, Elemental. In between are layers that target a single core, ... [more] »

Category: CE Seminar


Some recent developments of a non-dissipative DGTD method for time-domain electromagnetics

Dr. Stéphane Lanteri, INRIA Sophia Antipolis-Méditerranée

8 Mar 2012, 17:00; Location: S4|10-1

Nowadays, a variety of modeling strategies exist for the computer simulation of electromagnetic wave propagation in the time domain. Despite a lot of advances on numerical methods able to deal accurately and in a flexible way with complex geometries through the use of unstructured (non-uniform) discretization meshes, the FDTD (Finite Difference Time Domain) ... [more] »

Category: CE Seminar


Mechanoenzymatik: Atomistische Simulation biomolekularer Nanomaschinen

Prof. Dr. Helmut Grubmüller, Max-Planck-Institut für biophysikalische Chemie, Göttingen

3 Feb 2012, 17:15; Location: S2|14-024

Proteins are biological nanomachines. Virtually every function in the cell is carried out by proteins - ranging from protein synthesis, ATP synthesis, molecular binding and recognition, selective transport, sensor functions, mechanical stability, and many more. The combined interdisciplinary efforts of the past years have revealed how many of these ... [more] »

Category: CE Seminar


Control of Conservation Laws using a Relaxation Approximation

Dr. Sonja Steffensen, RWTH Aachen

1 Nov 2011, 15:30; Location: S4|10-142

 [more] »

Category: CE Seminar


Optimierung bei Partiellen Differentialgleichungen

Dr. Stephan Schmidt, Universität Trier

31 Oct 2011, 15:30; Location: S4|10-142

 [more] »

Category: CE Seminar


PDE-constrained optimal control problems with pointwise inequality constraints

Dr. Ira Neitzel, TU Berlin

27 Oct 2011, 08:30; Location: S4|10-142

 [more] »

Category: CE Seminar


Optimal control of Maxwell's equations and its applications

Dr. Irwin Yousept, TU Berlin

26 Oct 2011, 08:30; Location: S4|10-142

 [more] »

Category: CE Seminar


A Numerical Algorithm for Advancing Slow Features in Fast-Slow Systems without Scale Separation - A Young Measure Approach

Prof. Edriss Titi, University of California, Irvine & The Weizmann Institute of Science

18 Oct 2011, 14:00; Location: S2|15-51

In the first part of the talk, and in order to set the stage, we will offer a multi-scale and averaging strategy to compute the solution of a singularly perturbed system when the fast dynamics oscillates rapidly; namely, the fast dynamics forms cycle-like limits which advance along with the slow dy- namics. We describe the limit as a Young measure with ... [more] »

Category: CE Seminar


Analysis, Simulation und Mehrskalenansätze zur Feld/Netzwerk-Kopplung

Dr. Sebastian Schöps, Bergische Universität Wuppertal

11 Jul 2011, 14:00; Location: S2|17-103

Trotz zunehmend komplexer werdender elektromagnetischer Probleme machen heute neue Rechnerarchitekturen die numerische Simulation großer gekoppelter Probleme möglich. Die einzelnen Teilprobleme sind oft differential-algebraische Gleichungen, die aus der Ortsdiskretisierung partieller Differentialgleichungen (PDGLn) stammen. In diesem Vortrag werden ... [more] »

Category: CE Seminar


Parametrische Modellordnungsreduktion für die Finite-Elemente-Approximation linearer zeitinvarianter Systeme

Dr.-Ing. Ortwin Farle, Universität des Saarlandes

7 Jul 2011, 14:00; Location: S2|17-114

Die Diskretisierung linearer zeitinvarianter Systeme mittels finiter Elemente (FE) führt auf große, dünnbesetzte lineare Gleichungssysteme, deren Dimension typischerweise in der Größenordnung von Hunderttausend bis einigen Millionen liegt. Während ihre Lösung für eine einzelne Frequenz beim heutigen Stand der Technik kein Problem mehr bereitet, stellt die ... [more] »

Category: CE Seminar


Modelling and Simulation of Electrostimulating Implants in Bio-systems

Prof. Dr. Ursula van Rienen, Universität Rostock

30 Jun 2011, 17:00; Location: S4|10-1

 [more] »

Category: CE Seminar


Computational Methods for the Maxwell Eigenvalue Problem at Optical Frequencies

Dr.-Ing. Bastian Bandlow, Universität Paderborn

21 Jun 2011, 14:00; Location: S2|17-114

This talk is about the advancement of grid-based simulation algorithms for modelling electromagnetic wave propagation in photonics. For this purpose, existing algorithms for problems arising from the microwave range are extended for the analysis and the design of linear passive nanostructures at optical frequencies. The focus is put on the calculation of ... [more] »

Category: CE Seminar


Design und Optimierung der Dämpfungsmaßnahmen für strahlinduzierte Felder der CERN-SPL Studie

Dr.-Ing. Carsten Potratz, Universität Rostock

20 Jun 2011, 14:00; Location: S2|17-103

Elektromagnetische Felder, die durch die zu beschleunigenden Ladungsträger im Teilchenbeschleuniger hinterlassen werden, stellen eine wesentliche Limitierung für im Bau befindliche und zukünftige Teilbeschleunigerprojekte dar. Zur Dämpfung dieser als Wakefelder bezeichneten elektromagnetischen Felder werden spezielle Kopplerstrukturen eingesetzt, die den ... [more] »

Category: CE Seminar


From Analytical to Numerical Methods and Back: Trefftz Schemes, Whitney Forms, and Optical Magnets

Prof. Dr. Igor Tsukerman, University of Akron, USA

16 Jun 2011, 17:00; Location: S4|10-1

Several examples of a curious interplay between analytical and numerical methods will be presented. First, accurate local (semi-)analytical Trefftz approximations lead to high-order difference schemes and to singularity-free boundary-difference methods. Second, Whitney-like interpolation, well established in finite element analysis, is now put to a new use ... [more] »

Category: CE Seminar


Isogeometric Finite Elements

Prof. Dr. Bernd Simeon, TU Kaiserslautern

12 May 2011, 17:00; Location: S4|10-1

This talk will discuss the recently introduced class of isogeometric finite elements, which generalize the isoparametric concept to B-splines and NURBS (Non-Uniform Rational B-Splines). The latter are one of the standard descriptions for free form surfaces and various typical engineering shapes in Computer Aided Design (CAD) software. Besides explaining the ... [more] »

Category: CE Seminar


Influence of walls on transport and mixing in two-dimensional turbulence

Dr. Benjamin Kadoch, Laboratoire de Mécanique, Modélisation & Procédés Propres, M2P2-CNRS, Aix–Marseille Université and École Centrale Marseille, France

28 Apr 2011, 17:00; Location: S4|10-1

The influence of walls on the Lagrangian transport and mixing of passive scalars in turbulent two-dimensional flows is investigated. Two distinct geometries are considered by means of direct numerical simulation: a biperiodic domain and a circular domain with no-slip boundary conditions for velocity and zero flux for the scalar. A penalization method allows ... [more] »

Category: CE Seminar


Modeling of Flows with Interfaces

Prof. Dr.-Ing. Nikolaus Adams, TU München

17 Feb 2011, 16:00; Location: S4|10-1

Flows with interfaces exhibit interactions on a large range of scales, resulting in large demands on compute power for simulations. Single-phase flows already can exhibit a large range of strongly coupled scales whose efficient computational modeling poses a challenge by itself. Immersed interfaces add small-scale transport phenomena and can dominate the ... [more] »

Category: CE Seminar


Theory and numerical simulations of wave generation in atomization using the volume of fluid method

Prof. Stéphane Zaleski, Université Pierre et Marie Curie, Paris

10 Feb 2011, 17:00; Location: S4|10-1

We describe computations performed using the Gerris code, an open-source software implementing finite volume solvers on an octree adaptive grid together with a piecewise linear volume of fluid interface tracking method. The parallelisation of Gerris is achieved by domain decomposition into a large number of grains (a "forest of tree" approach) ... [more] »

Category: CE Seminar


Direkte Simulation von kompressiblen Mehrphasenströmungen

Dr. Felix Jägle, Universität Stuttgart

3 Feb 2011, 17:00; Location: S4|10-1

 [more] »

Category: CE Seminar


Parameteridentifikation und optimale Steuerung bei partiellen Differentialgleichungen

Prof. Dr. Arnd Rösch, Universität Duisburg

2 Feb 2011, 17:15; Location: S2|14-24

Bei der Lösung von Optimierungsaufgaben bei partiellen Differentialgleichungen und von Parameteridentifikationsaufgaben werden häufig sehr ähnlich mathematische Probleme untersucht. Dabei haben die mathematischen Gebiete Inverse Probleme und Optimale Steuerung sehr unterschiedliche Herangehensweisen. Ausgehend von der Korrektheitsdefinition von Hadamard ... [more] »

Category: CE Seminar


Konvergenz und Optimalität adaptiver Finite Elemente Verfahren

Prof. Dr. Kunibert Siebert, Universität Duisburg

26 Jan 2011, 17:15; Location: S2|14-24

Adaptive Finite Elemente Verfahren werden seit den 1970er Jahren erfolgreich zur effizienten numerischen Lösung partieller Differenzialgleichungen verwendet. Das übliche adaptive Verfahren ist eine Iteration der Form SOLVE → ESTIMATE → MARK → REFINE. Die meisten Arbeiten zu adaptiven Finiten Elementen befassen sich mit dem Modul ESTIMATE, ... [more] »

Category: CE Seminar


Optimal control of Maxwell's equations with regularized state constraints

Dr. Irwin Yousept, TU Berlin

6 Dec 2010, 17:00; Location: S4|10-1

In this talk, we consider a state--constrained optimal control problem of Maxwell's equations based on a 'vector potential ansatz' for the control. The pointwise state constraints here play an important role to prevent singularities or to achieve certain $L^p$--regularity of the optimal state. Due to the lack of regularity of the control--to--state ... [more] »

Category: CE Seminar


Resource Allocation in Wireless Networks: From Interference Management to Broadcast Property Exploitation

PD Dr.-Ing. Slawomir Stanczak, Fraunhofer Lab for Mobile Communications (FhG-MCI)

3 Dec 2010, 10:00; Location: S3|06-235

 [more] »

Category: CE Seminar


Robots and the Human

Prof. Oussama Khatib, Artificial Intelligence Laboratory, Stanford University

16 Nov 2010, 13:30; Location: Darmstadtium, SIMPAR Conference

Robotics is rapidly expanding into the human environment and vigorously staying engaged in its emerging challenges. From a largely dominant industrial focus, robotics has undergone, by the turn of the new millennium, a major transformation in scope and dimensions. This expansion has been brought about by the maturity of the field and the advances in its ... [more] »

Category: CE Seminar


Multicomponent AM-FM Modelling of Nonstationary Signals

Prof. Francesco Gianfelici, Aalborg University, Denmark

11 Nov 2010, 17:00; Location: S4|10-1

Multicomponent AM-FM models, also known as McAulay-Quatieri models in audio and speech processing, are highly parametric representations of non stationary signals that are able to effectively represent a large class of real phenomena with no limitations in terms of signal kind, applicative domain, and so on. During recent decades, the elegant formulation of ... [more] »

Category: CE Seminar


A Signal Processing Approach to the Analysis and Modeling of Driving Behavior

Prof. Kazuya Takeda, Graduate school of information science, Nagoya University

28 Oct 2010, 17:00; Location: S4|10-1

Since 2004, the driving behavior of more than five hundred drivers has been collected while subjects drove in real traffic, by researchers at Nagoya University in Japan. The main purpose of this data collection is to build corpora (large bodies of representative data) for a new research challenge - human behavior signal processing. Environmental and ... [more] »

Category: CE Seminar


The inverse elastostatic problem

Dr. Mathieu Sellier, University of Canterbury, New Zealand

23 Sep 2010, 17:00; Location: S4|10-1

 [more] »

Category: CE Seminar


Multigrid techniques for thin liquid films and droplets

Dr. Mathieu Sellier, University of Canterbury, New Zealand

21 Sep 2010, 15:00; Location: L1|08-4 and 23

This talk is provided together with the Center of Smart Interfaces (CSI). [more] »

Category: CE Seminar


Advanced Modeling Techniques for 3D Electronic Package Signal Integrity and Power Integrity

Prof. ErPing Li, Institute of High Performance Computing A*STAR, Singapore

13 Sep 2010, 11:30; Location: S4|10-1

Driven by the impressive growth of the communication industry, we see a rapid convergence of digital computing and analog wireless technology. This has become possible due to the progress of, semiconductor technology into the nanometer regime which is going to continue for the next ten to fifteen years. High-level integration with unprecedented ... [more] »

Category: CE Seminar


Structural optimization - Towards a multiscale approach

Prof. Dr. Michael Stingl, Universität Erlangen-Nürnberg

26 Aug 2010, 17:00; Location: S2|14-024

 [more] »

Category: CE Seminar


Adaptive higher-order finite element methods for multiphysics coupled problems

Prof. Dr. Pavel Solin, University of Nevada, Reno/ Institute of Thermomechanics, Prague

22 Jul 2010, 17:00; Location: S4|10-1

In this presentation I will briefly introduce my research group and its goals. I will explain why we are interested in adaptive finite element methods based on computational, as opposed to mathematical/analytical error estimates. Main principles of adaptive higher-order finite elementi methods (hp-FEM) will be explained and demonstrated via live ... [more] »

Category: CE Seminar


Stochastic Polynomial Approximations for Partial Diff erential Equations with Random Input Data

Prof. Dr. Fabio Nobile, Politecnico di Milano

8 Jul 2010, 17:00; Location: S4|10-1

When building a mathematical model to describe the behavior of a physical system, one has often to face a certain level of uncertainty in the proper characterization of the model parameters and input data. An example is given by the study of groundwater flow, where the subsurface permeability is largely unknown and often reconstructed from few available ... [more] »

Category: CE Seminar


Towards Robust Visual Pattern Recognition: from Emotion Recognition to Human Activity Monitoring

Prof. Dr. Salim Bouzerdoum, University of Wollongong, Australia

1 Jul 2010, 17:00; Location: S4|10-1

One of the challenges of visual pattern recognition is robustness to photometric and geometric distortions that occur in uncontrolled natural environments. To this end, we have proposed recently a new paradigm for visual pattern recognition which combines feature extraction and classification in one hierarchical image classification architecture. The ... [more] »

Category: CE Seminar


Non-traditional Finite Difference and Boundary Difference Methods

Prof. Dr. Igor Tsukerman, University of Akron, USA

15 Jun 2010, 17:00; Location: S4|10-1

Traditional finite-difference methods are typically based on Taylor expansions of the differential operator. The generalized finite-difference calculus of Flexible Local Approximation MEthods (FLAME) often dramatically improves the accuracy by replacing these Taylor expansions with Trefftz functions – local solutions of the underlying differential ... [more] »

Category: CE Seminar


Design Principles of Wind Turbine Blades

Prof. Alois Schaffarczyk, FH Kiel

4 Jun 2010, 13:00; Location: L1|08-4 and 23

This talk is provided together with the Center of Smart Interfaces (CSI).  [more] »

Category: CE Seminar


Information Theory meets Biology

Prof. Martin Bossert, University Ulm

21 May 2010, 10:30; Location: S3|06-249

Es wird eine kurze Übersicht über die DFG-Projekte im DFG Schwerpunktprogramm SPP 1395 (InKoMBio) gegeben. Nach einer kurzen Einführung in die elementaren informationstheoretischen Begriffe wird auf die Analyse binärer polynomialer Systeme mittels der Fourier Analyse eingegangen. (Vorstellung des DFG-Projektes: Die Evolutive Anpassung der transkriptionellen ... [more] »

Category: CE Seminar


Impulsbasierte Dynamiksimulation

Prof. Jan Bender, TU Darmstadt

11 May 2010, 16:30; Location: S3|05-074 (IGD)

Die dynamische Simulation ist ein aktueller Forschungsbereich mit vielen Anwendungsgebieten. Dieser Bereich umfasst u.a. die Simulation von Starrkörpern, Textilien und Weichkörpern. Dynamische Simulation ist heutzutage ein wichtiger Bestandteil im Entwicklungsprozess von komplexen Maschinen (wie z.B. in der Robotik), im Forschungsbereich der Medizin, in der ... [more] »

Category: CE Seminar


Variationelle Mehrskalen-Methoden für turbulente Strömungen und Verbrennung

Dr.-Ing. Volker Gravemeier, TU München

7 May 2010, 15:15; Location: L1|01-K 328

Die variationelle Mehrskalen-Methode wurde vor ca. 15 Jahren zum ersten Mal der Fachwelt als theoretisches Rahmenwerk für die Entwicklung numerischer Methoden für Probleme mit sehr breiten Skalenspektren vorgestellt. Als Beispiele für solche Mehrskalen-Probleme kann man u.a. viele Problemstellungen der Materialmodellierung, aber auch z.B. turbulente ... [more] »

Category: CE Seminar


Numerische Feldberechnung in der Anwendung bei Fragestellungen Elektrischer Maschinen

Prof. Dr.-Ing. habil. Dr. h.c. Kay Hameyer, RWTH-Aachen

6 May 2010, 17:00; Location: S2|17-103

 [more] »

Category: CE Seminar


Das Internet der Dinge - eine Bestandsaufnahme

Dr.-Ing. Heinrich Stüttgen, NEC Laboratories Europe

15 Apr 2010, 14:00; Location: S2|17-114

 [more] »

Category: CE Seminar


Examples of Adaptive Filtering in Hearing Aids: Beamforming and Feedback Cancellation

Dr.-Ing. Henning Puder, Siemens Audiologische Technik, Erlangen

23 Mar 2010, 17:15; Location: S2|17-103

 [more] »

Category: CE Seminar


Mensch-Maschine-Interaktion in der industriellen Informationsverarbeitungskette

Dr. Rainer Heiß, HA-WI Kunststoffe, Bad Laasphe

23 Mar 2010, 16:30; Location: S2|17-103

 [more] »

Category: CE Seminar


Measure, Lebesgue Integration, The Dirac Delta, Lebesgue-Stieltjes Integration and Cramer’s Representation

Dr. Roy Howard, Curtin University, Perth, Australia

11 Feb 2010, 17:00; Location: S4|10-1

Part 1: Singularity type functions, such as the Dirac delta, are usually defined assuming that they operate on well defined functions - usually called ‘good functions’. The results that hold for singular- ity functions, and for the good function case, do not hold, in general, for the usual case where non- good functions are to be considered and this has led ... [more] »

Category: CE Seminar


Strömungsablösung in laminar-welligen Rieselfilmen

Dipl.-Ing. Georg Dietze, RWTH Aachen

26 Jan 2010, 12:00; Location: L1|08-4

Rieselfilme (d.h. dünne durch Gravitation getriebene flüssige Filme) spielen in einer Vielzahl technischer Prozesse in der Energie- und Verfahrenstechnik eine Rolle. In Kühltürmen wird z.B. Wasser auf sogenannte Rieseleinbauten gesprüht, wodurch sich ein verdunstender Film ausbildet. Rieselfilme aus flüssigem Lithium werden in der Kernfusionsforschung zur ... [more] »

Category: CE Seminar


Initial Value Problem Formulation of Time Domain BEM and Application to Wake Field Analysis

Prof. Hideki Kawaguchi, Muroran Institute of Technology, Muroran, Japan

18 Jan 2010, 16:00; Location: S2|17-103

Although Boundary Element Method (BEM) requires us heavy calculation cost and large required memory, it givs us some remarkable advantages due to property of surface mesh such as in open bounary problems, moving boundary problems, optimized shape design problems, inverse problems, coupling problems with moving charged particles, and so on. This means that ... [more] »

Category: CE Seminar


Transient Electromagnetic Field Coupling with an Airborne Vehicle in the Presence of its Conducting Exhaust Plume

Dr. Sisir Kumar Nayak, Royal Institute of Technology, Stockholm

14 Dec 2009, 15:30; Location: S2|17-103

Airborne vehicle or and its payload are extremely expensive and their loss as a result of a nearby lightning strike is highly undesirable. Even though one could launch only under ideal weather conditions, the cost involved with long launch delays could be very high. So in this age of all weather usage of airborne launch vehicles, it has become necessary to ... [more] »

Category: CE Seminar


Monaural and binaural beamforming for hearing aids

Dr.-Ing. Henning Puder, Siemens Audiologische Technik

7 Dec 2009, 17:00; Location: S4|10-1

Hearing impaired people suffer from significant problems of understanding speech in noisy environments. The damage of the outer hair cells in the cochlear causes a reduced frequency resolution or higher frequency masking of the auditory perception, respectively. The only possibility to compensate for this effect is to offer people a signal with reduced ... [more] »

Category: CE Seminar


Turbulence transition in shear flows: What can we learn from pipe flow?

Prof. Dr. Bruno Eckhardt, Philipps-Universität Marburg

4 Nov 2009, 15:15; Location: S1|10-103

According to textbook wisdom, flow down a pipe becomes turbulent near a Reynolds number of about 2000. This simple statement misses many subtleties of the transition: the absence of a linear stability of the laminar flow, the sensitive dependence on perturbations that sometimes succed and sometimes fail to induce turbulence and the unexpected observation ... [more] »

Category: CE Seminar


Cognition: The Enabler of New Generation of Engineering Systems

Prof. Dr. Simon Haykin, McMaster University, Hamilton, Canada

14 Sep 2009, 16:00; Location: S3|06-249

When we speak of cognition, we usually think of the human brain: A powerful and highly complex information-processing system. So, I set the stage for my lecture by describing the Action-Perception Cycle that is an inherent characteristic of the brain. With the Action-Perception Cycle as the focus of attention throughout the lecture, I will then describe ... [more] »

Category: CE Seminar


Mapping and Exploration for Search and Rescue with Humans and Mobile Robots

Dr. Alexander Kleiner, Albert-Ludwigs-Universität Freiburg

11 Sep 2009, 15:15; Location: S2|02-A102 (Robert-Piloty-Gebäude)

Urban Search And Rescue (USAR) is a time critical task since survivors have to be rescued within the first "golden" 72 hours. One goal in Rescue Robotics is to support emergency response by mixed-initiative teams consisting of humans and robots. Their task is to explore the disaster area rapidly while reporting victim locations and hazardous areas ... [more] »

Category: CE Seminar


Extrahieren verborgener Strukturen aus Daten mit latenten Variablen

Dr. Roland Memisevic, University of Toronto, Canada

11 Sep 2009, 08:45; Location: S2|02-A102 (Robert-Piloty-Gebäude)

Latente Variablen haben eine langjährige Geschichte in der Modellierung komplexer statistischer Zusammenhänge. Indem sie versteckte Strukturen in Daten selbständig aufgreifen und repräsentieren können, ermöglichen sie es, erstaunlich elegante und einfache Modelle einer Vielzahl komplexer Phänomene zu generieren. Klassische Beispiele für Verfahren, die auf ... [more] »

Category: CE Seminar


Scientific Computing on Multi-GPU Systems

Dr. Robert Strzodka, MPI Saarbruecken

29 Jun 2009, 11:40; Location: S3|05-074

The advances in hardware functionality and programmability of graphics processors (GPUs) have greatly increased their appeal as add-on co-processors for scientific computing. However, for large-scale computations a desktop with a single GPU is not sufficient and parallel workstations or even clusters with multiple GPUs must be considered. This talk will ... [more] »

Category: CE Seminar


Interactive Texture-based Flow Visualization

Prof. Charles Hansen, SCI Institute, University of Utah

22 Jun 2009, 15:30; Location: S3|05-074

Flow fields play an important role in a wide range of scientific, engineering, and medical disciplines. Due to the advancements in computing technologies and computational fluid dynamics (CFD), recently we have seen a large number of flow datasets with ever increasing size and complexity from numerical fluid simulations. In order to obtain valuable ... [more] »

Category: CE Seminar


Simulation der Notwasserung von Verkehrsflugzeugen

Prof. Dr.-Ing. Thomas Rung, TU Hamburg-Harburg

17 Jun 2009, 15:15; Location: S1|03-252

Am 15. Januar 2009 gelang dem Piloten einer Maschine vom Typ A320 der US Airways nach dem Ausfall beider Triebwerke eine Notwasserung auf dem Hudson River in New York. Alle 155 Insassen überstanden die Notwasserung nahezu unverletzt. Der Vortrag behandelt einen randständigen Bereich des Flugzeugbaus, der sich mit der Notwasserung und Schwimmfähigkeit von ... [more] »

Category: CE Seminar


Model predictive control of flows

Prof. Dr. Michael Hinze, University of Hamburg

16 Jun 2009, 17:00; Location: S4|10-1

We exploit ideas from model predictive control to construct nonlinear distributed and boundary controllers for flow governed by the instationary Navier Stokes equations or the Boussinesq approximation. We numerically test the performance of the controllers considering as example control of the wake of the circular cylinder in the laminar flow regime, and ... [more] »

Category: CE Seminar


Excitation-Adaptive FDTD Scheme Design by the Method of Undetermined Coefficients for Specified Spectral Orders of Accuracy

Bezalel Finkelstein, Tel-Aviv University

9 Jun 2009, 10:00; Location: S2|17-103

 [more] »

Category: CE Seminar


Some recent results in cooperative wireless relaying

Prof. Dr. Armin Wittneben, Swiss Federal Institute of Technology (ETH), Zurich

4 Jun 2009, 10:00; Location: S3|06-146

Existing wireless networks are designed for coexistance, i.e. essentially for interference avoidance. In contrast cooperative wireless communication intentionally accepts interference to optimize network performance. In this talk we start out with a brief introduction to cooperative wireless communication and in particular wireless relaying. Subsequently ... [more] »

Category: CE Seminar


Implicit LES: Theory and Application

Prof. Dr.-Ing. Nikolaus A. Adams, Technische Universität München

20 May 2009, 15:15; Location: S1|03-252

A systematic framework for implicit LES modeling will be presented. Unlike previous approaches to ILES, where given nonlinearly stable discretizations are employed without a priori analysis of the effect of the truncation error, with the proposed framework ALDM (adaptive local deconvolution model) physically consistent modeling is introduced to ILES. With ... [more] »

Category: CE Seminar


Beiträge zu Spektral-Elemente-Methoden und Anwendungen in der Strömungsmechanik

Dr.-Ing. habil. Jörg Stiller, Technische Universität Dresden

13 May 2009, 15:15; Location: S1|03-252

Spektralelementmethoden (SEM) kombinieren die Genauigkeit von Spektralmethoden mit der Flexibilität von Finite-Elemente-Verfahren. Dieser Anspruch lässt sich In der Praxis nicht immer leicht verwirklichen.
Dieser Vortrag startet mit einigen Erfolgsbeispielen aus dem SFB 609 an der TU Dresden.
Der zweite Teil widmet sich der implementierung von ... [more] »

Category: CE Seminar


A Hybrid Optimization Scheme Combining Pattern Search and Gaussian Process

Genetha Gray, PhD, Sandia National Laboratories, Livermore

5 May 2009, 17:00; Location: S4|10-1

Every optimization technique has inherent strengths and weaknesses. Moreover, some optimization algorithms contain characteristics which make them better suited to solve particular kinds of problems. Hybridization, or the combining of two or more complementary, but distinct methods, allows the user to take advantage of the beneficial elements of multiple ... [more] »

Category: CE Seminar


On the Manifold-Mapping Technique for Optimization Problems with Partial Differential Equation Constraints

Prof. Dr. Domenico Lahaye, TU Delft

27 Apr 2009, 16:00; Location: S2|17-103

Optimization problems with partial differential equations constraints are computationally challenging problems that appear in a wide range of engineering applications. Space-mapping techniques allow to speed their solution procedure by extracting information from approximate models such as for instance analytical and lumped parameter approximations. Early ... [more] »

Category: CE Seminar


Numerical Investigations for an Extension of FDTD on Tetrahedral Grids

Prof. Lorenzo Codecasa, Ph.D., Politecnico di Milano

16 Apr 2009, 16:00; Location: S2|17-114

The Finite Difference Time Domain (FD-TD) algorithm, originally proposed by K. S. Yee, is one of the most common algorithm for the time-domain simulation of electromagnetic problems. This is essentially due to the fact that the FD-TD algorithm is explicit, so that its computationally complexity and memory requirement are low, and to the fact that the limit ... [more] »

Category: CE Seminar


Computability and Computational Complexity of/in Physical Theories

Dr. Martin Ziegler, TU Wien

9 Apr 2009, 14:30; Location: S4|10-1

We combine the classical theories of discrete computation (Turing computability and complexity classes like NP) and real number computation (Recursive Analysis and BSS model) with Theoretical Physics in order to
1. investigate physical foundations of computing (Church-Turing Hypothesis) and
2. devise a complexity theory of computer simulation ... [more] »

Category: CE Seminar


Understanding anisotropic mesh adaptation from the perspective of uniform meshes in a metric space: Theory and applications

Prof. Dr. Weizhang Huang, University of Kansas

12 Mar 2009, 17:00; Location: S1|03-123

Anisotropic mesh adaptation has proven to be a useful tool for enhancing accuracy and efficacy in the numerical solution of partial differential equations, especially those exhibiting anisotropic features in their solutions and/or structures.  On the other hand, the mathematical characterization of anisotropic meshes has not been well understood. In ... [more] »

Category: CE Seminar


Simulation of microelectronic structures using potentialfieldsolving and optimal parameter setting methods

Wim Schoenmaker, CTO, MAGWEL N.V., Leuven (B)

5 Feb 2009, 16:00; Location: S2|17-103

The simulation of electromagnetic phenomena using field solvers for semiconductor structures demands the use of potentials and vector potentials because the local energy, more than the local force, determines the electron and hole distributions. The ideas underlying the finiteintegration method are applied to the potential fields leading to a discretization ... [more] »

Category: CE Seminar


Time Domain Electromagnetic Algorithms and Their Application to Photonics

Prof. Trevor Benson, University of Nottingham

29 Jan 2009, 16:00; Location: S2|17-103

Electromagnetic modelling for photonics shares many common problems with other applications. These include the requirement for: multi-scale modelling, requiring an accurate description of small features that can have significant influence on the performance of a significantly larger system; addressing multi-physics problems operating on timescales; highly ... [more] »

Category: CE Seminar


Discontinuous-Galerkin-Verfahren für instationäre Wellen- und Diffusionsprobleme

Prof. Claus-Dieter Munz, Universität Stuttgart

22 Jan 2009, 17:00; Location: S2|17-103

Der Vortrag gibt eine Übersicht über die Entwicklung von Discontinuous-Galerkin-Verfahren für instationäre Probleme. Durch ihre Flexibilität und die Qualität der Näherungslösungen werden diese Verfahren als eine künftige Möglichkeit gesehen, numerische Simulationen in komplexen Geometrien effizienter zu machen. Das DG-Verfahren kann als eine Kombination von ... [more] »

Category: CE Seminar


Parallel Computing with CUDA

Prof. Dr. Michael Goesele, TU Darmstadt

18 Dec 2008, 17:00; Location: S4|10-1

Modern graphics cards are not only powerful rendering systems but can also be used as massively parallel compute devices. Applications that are well suited for the cards' SIMD architecture can achieve speed ups of more than two orders of magnitude compared to single CPU implementations. In this talk, I will give an introduction to NVIDIA's CUDA ... [more] »

Category: CE Seminar


A Research On Natural Convection Under A Magnetic Field: Numerical Simulation And The Construction Of A Reduced Dynamical Model

Dr. Ersan Güray, Middle East Technical University, Ankara

17 Dec 2008, 11:00; Location: S4|10-1

 [more] »

Category: CE Seminar


Fast and Accurate Solutions of Very Large Electromagnetics Problems with the Parallel Multilevel Fast Multipole Algorithm

Özgür Ergül, Ph.D. Candidate, Bilkent University, Ankara

11 Dec 2008, 17:00; Location: S2|17-103

The multilevel fast multipole algorithm (MLFMA) is a powerful method for the fast and efficient solution of scattering and radiation problems in electromagnetics. Real-life problems formulated with surface integral equations can be solved iteratively, where the required matrix-vector multiplications are performed efficiently by MLFMA. However, many ... [more] »

Category: CE Seminar


Modellierung von Messfehlern mit stochastischen partiellen Differentialgleichungen

Prof. Dr. Wilhelm Stannat, TU Darmstadt

4 Dec 2008, 18:00; Location: S2|17-103

 [more] »

Category: CE Seminar


Simulation stochastischer partieller Differentialgleichungen

Prof. Dr. Klaus Ritter, TU Darmstadt

4 Dec 2008, 17:00; Location: S2|17-103

 [more] »

Category: CE Seminar


Theoretische Elektrotechnik in Bewegung: Dynamische Simulation elektromechanischer Systeme

Prof. Dr.-Ing. Stefan Kurz, Frankfurt

20 Nov 2008, 17:00; Location: S2|17-103

Elektromechanische Systeme werden durch die Maxwellschen Gleichungen in Verbindung mit der Newtonschen Bewegungsgleichung beschrieben. Die physikalischen Gesetze liegen dabei in Form (partieller) Differentialgleichungen vor, die durch Anwendung numerischer Verfahren schrittweise in lineare Gleichungssysteme überführt und auf dem Rechner gelöst werden. ... [more] »

Category: CE Seminar


Technische Universität Darmstadt

Graduate School CE
Dolivostraße 15
D-64293 Darmstadt

Phone+49 6151/16-24401
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