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Archive 2014

Date / Time Speaker Title Location
26 February 2014
16:15-17:15 		Prof. Dr. Peng Chen
EPFL Lausanne
Event Details
Speaker invited by Christoph Schwab
Abstract Several computational challenges, including high-dimensionality, low-regularity, arbitrary probability distribution, expensive deterministic solver, are commonly faced for the solution of some typical uncertainty quantification problems. In this talk, I will present an accurate and efficient reduced basis method to tackle these challenges, with particular applications to statistical moments evaluation, risk analysis and stochastic optimal control problems.
Reduced basis method for uncertainty quantification problems
HG D 1.2
10 March 2014
16:15-17:15 		Dr. Oliver Sander
RWTH Aachen
Event Details
Speaker invited by Philipp Grohs
Abstract Geodesic finite elements are a novel way to discretize problems involving functions with values on a Riemannian manifold. Examples for such problems include Cosserat materials and liquid crystals. The basic idea is to rewrite Lagrangian interpolation as a minimization problem, which can be generalized to nonlinear spaces. Geodesic finite elements of any order can be constructed, and are conforming in the sense that they are first-order Sobolev functions. The construction is equivariant under isometries of the value manifold, which implies that frame-indifference in mechanics is preserved. Optimal discretization error bounds have been shown analytically, and can be observed in numerical experiments. We present the theory of geodesic finite elements and give a few example applications.
Geodesic Finite Elements
HG E 1.2
12 March 2014
16:15-17:15 		Prof. Dr. Remi Abgrall
Universität Zürich
Event Details
Speaker invited by Siddhartha Mishra
Abstract In this talk, we first review the so-called Residual distribution scheme, a variant of non linear finite element methods for solving hyperbolic problems, and show how to extend the construction to advection-diffusion problems using conformal meshes. Second and third order methods will be detailed, the extension to higher order is straightforward. The problems considered range from pure diffusion to pure advection. The approximation of the solution is obtained using standard Lagrangian finite elements and the total residual of the problem is constructed taking into account both the advective and the diffusive terms in order to discretize with the same scheme both parts of the governing equation. To cope with the fact that the normal component of the gradient of the numerical solution is discontinuous across the faces of the elements, the gradient of the numerical solution is reconstructed at each degree of freedom of the grid and then interpolated with the same shape functions used for the solution. Linear and non-linear schemes are constructed and their accuracy is tested with the discretization of advection-diffusion and anisotropic diffusion problems. We end the talk by an extension to the Navier Stokes equations with 3D examples. This is a joint work with Dante de Santis (INRIA).
High-order preserving residual distribution schemes for advection-diffusion scalar problems on arbitrary grids
HG E 1.2
19 March 2014
16:15-17:15 		Prof. Dr. Helge Holden
NTNU Trondheim
Event Details
Speaker invited by Siddhartha Mishra
Abstract The Camassa--Holm (CH) equation reads $u_t-u_{txx}+\kappa u_x+3uu_x-2u_xu_{xx}-uu_{xxx}=0$ where $kappa$ is a real parameter. We are interested in the Cauchy problem on the line with initial data in $H^1$. There is a well-known and well-studied dichotomy between two distinct classes of solutions of the CH equation. The two classes appear exactly at wave breaking where the spatial derivative of the solution becomes unbounded while its $H^1$ norm remains finite. We here introduce a novel solution concept gauged by a continuous parameter $\alpha$ in such a way that $\alpha=0$ corresponds to conservative solutions and $\alpha=1$ gives the dissipative solutions. This allows for a detailed study of the difference between the two classes of solutions and their behavior at wave breaking. We also extend the analysis to a two-component Camassa--Holm system. This is joint work with Katrin Grunert (NTNU) and Xavier Raynaud (SINTEF).
What is between conservative and dissipative solutions for the Camassa--Holm equation?
HG E 1.2
26 March 2014
16:15-17:15 		Prof. Dr. Max Wardetzky
Universität Göttingen
Event Details
Speaker invited by Ralf Hiptmair
Abstract Elastic curves -- thin strips of elastic material -- have intrigued mathematicians and physicists for centuries, including Galileo, the Bernoullis, Euler, Born, and others. One way to describe elastic curves is to define them as minimizers of the so-called bending energy (the total squared curvature) of a curve. This view leads to the notion of discrete elastic curves -- polygonal curves that minimize a certain discrete bending energy. In my talk, besides presenting some of the fascinating history of elastic curves, I will discuss, using tools from variational analysis, how discrete elastic curves approximate their classical smooth counterparts.
Discrete Elastic Curves
HG E 1.2
2 April 2014
16:15-17:15 		Prof. Dr. Mario Bebendorf
Universität Bonn
Event Details
Speaker invited by Ralf Hiptmair
Abstract Hierarchical (H-)matrices provide a means to construct ecient and robust approximate preconditioners for the solution of elliptic boundary value problems. In order to cope with increasing condition numbers, the approximation accuracy, however, has to be adapted to the condition number, which deteriorates the eciency. We present a new approach, in which special vectors are preserved during the truncated H-matrix operations. This will be shown to lead to spectral equivalence even without adaptation of the approximation accuracy.
Improving hierarchical matrix preconditioners via preservation of vectors
HG E 1.2
16 April 2014
16:15-17:15 		Dr. Steffen Weisser
Universität Saarbrücken
Event Details
Speaker invited by Ralf Hiptmair
Abstract 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 is one of the new promising strategies which yields conforming approximations on polygonal and polyhedral meshes, respectively. This flexibility is obtained by special trial functions which are defined implicitly as solutions of local boundary value problems related to the underlying differential equation. Due to this construction, the approximation space already inherit some properties of the unknown solution. These implicitly defined trial functions are treated by means of boundary element methods (BEM) in the realization. The presentation gives a short introduction into the BEM-based FEM and deals with recent challenges and developments. The basic idea in the construction of trial functions is generalized, and thus, trial functions of arbitrary order are obtained. With the help of an appropriate interpolation operator, it is possible to prove optimal rates of convergence in the $H^1$- as well as in the $L_2$-norm for the BEM-based FEM on uniform refined polygonal meshes with star-shaped elements. Furthermore, by using a posteriori error estimates, it is possible to achieve optimal rates of convergence even for problems with non-smooth solutions on adaptive refined polygonal meshes. Several numerical experiments confirm the theoretical results.
Conforming Trefftz-like basis functions on polygonal and polyhedral meshes with realization in BEM-based FEM
HG E 1.2
30 April 2014
16:15-17:15 		Prof. Dr. Ernst Hairer
Universität Genf
Event Details
Speaker invited by Kaspar Nipp
Abstract Due to the presence of parasitic roots in linear multistep methods, the numerical solution of differential (and differential-algebraic) equations gives rise to non-physical oscillations. For strictly stable methods these oscillations are rapidly damped, so that the numerical solution behaves like that of a one-step method (Kirchgraber 1986, Stoffer 1993). For symmetric methods these oscillations, although with small amplitude in the beginning, can grow exponentially with time and soon dominate the error in the numerical approximation. Certain symmetric multistep methods for second order differential equations, when applied to (constrained) Hamiltonian systems, have the feature that these oscillations remain bounded and small (below the discretization error of the smooth solution) over very long time intervals. Numerical experiments are presented and a proof of the long-time behaviour is outlined. The technique of proof is backward error analysis combined with modulated Fourier expansions. The presented results have been obtained in collaboration with Christian Lubich and Paola Console.
Control of parasitic oscillations in linear multistep methods
HG E 1.2
12 May 2014
16:15-17:15 		Prof. Dr. Jan van Neerven
Delft University of Technology
Event Details
Speaker invited by Arnulf Jentzen
Abstract In this talk I present an overview of the joint work with Mark Veraar and Lutz Weis which has led to the construction of a stochastic integral with respect to Brownian motion for stochastic processes taking values in a UMD Banach space. What makes this integral particularly useful is that two-sided estimates can be shown for the L^p-norm of this integral which provide a natural extension of the Ito isometry and Burkholder's inequality. We show how this integral can be used to prove existence, uniqueness and regularity for semilinear stochastic PDEs.
Stochastic integration in UMD Banach spaces
HG D 1.2
28 May 2014
16:00-17:00 		Dr. Markus Bachmayr
RWTH Aachen
Event Details
Speaker invited by Christoph Schwab
Abstract We consider the application of subspace-based tensor formats to high-dimensional operator equations on Hilbert spaces, and combine such tensor representations with adaptive basis expansions of the arising lower-dimensional components. This leads to highly nonlinear approximation problems. We review the general framework of [1], where we have analyzed an iterative method which is not tied to a fixed background discretization and under standard assumptions can be guaranteed to converge to the solution of the continuous problem. Furthermore, under additional low-rank representation sparsity assumptions, the scheme constructs an approximate solution using a number of arithmetic operations that is optimal up to fixed logarithmic terms. Here, the major difficulty lies in obtaining meaningful bounds for the tensor ranks of iterates. In this talk, we focus on problems posed on function spaces for which the inner product does not induce a cross norm, e.g., problems on Sobolev spaces such as second-order elliptic PDEs on product domains. We discuss the additional issues that arise in this case (which are connected to general obstructions with preconditioning in the context of low-rank expansions), outline how one can again obtain a method whose complexity can be analyzed, and show some first numerical experiments. The presented results are joint work with Wolfgang Dahmen. _____ [1] M. Bachmayr, W. Dahmen: Adaptive Near-Optimal Rank Tensor Approximation for High-Dimensional Operator Equations, Foundations of Computational Mathematics, 2014, DOI 10.1007/s10208-013-9187-3.
Adaptive Low-Rank Methods for High-Dimensional Second-Order Elliptic Problems
HG E 1.2
4 September 2014
11:00-11:45 		Prof. Dr. Wolf-Jürgen Beyn
Universität Bielefeld, Germany
Event Details
Speaker invited by Maria Lopez-Fernandez
Abstract We consider the numerical solution of semilinear time-dependent partial differential equations that support the propagation of nonlinear waves such as traveling, rotating or spiral waves. Depending on initial data, the solutions of such systems often show multiple patterns which are composed of several waves that either travel towards each other and collide (strong interaction) or miss each other and depart (weak interaction). Such multiple patterns look like linear superpositions of single waves which, however, cannot be true in a strict sense due the nonlinear character of the system.
We suggest a numerical method that allows to handle several coordinate frames in which the single patterns can stabilize while still keeping their full nonlinear interaction.The procedure is adaptive in the sense that the position of the single frames is not prescribed a-priori but determined during computation. Several numerical experiments illustrate the method for multi-fronts in one space dimension and for multiple spinning solitons in two space dimensions. The approach extends an earlier method (called the freezing method), which allows to stabilize dynamic patterns in a single co-moving frame. For the case of weak interaction in one space dimension, we present a theoretical result which shows stability with asymptotic phase for the decomposition system.
Stability and computation of interacting nonlinear waves
Y27 H 28
16 September 2014
10:15-11:15 		Prof. Dr. Gitta Kutyniok
TU Berlin
Event Details
Speaker invited by Ralf Hiptmair
Abstract Many important problem classes are governed by anisotropic features such as singularities concentrated on lower dimensional embedded manifolds, for instance, edges in images or shear layers in solutions of transport dominated equations. While the ability to reliably capture and sparsely represent anisotropic structures is obviously the more important the higher the number of spatial variables is, principal difficulties arise already in two spatial dimensions. Since it was shown that the well-known (isotropic) wavelet systems are not capable of efficiently approximating such anisotropic features, the need arose to introduce appropriate anisotropic representation systems. Among various suggestions, shearlets are the most widely used today. Main reasons for this are their optimal sparse approximation properties within a model situation in combination with their unified treatment of the continuum and digital realm, leading to faithful implementations. An additional advantage is the availability of stable compactly supported systems for high spatial localization. In this talk, we will provide an introduction to the anisotropic representation system of shearlets, in particular, compactly supported shearlets, present the main theoretical results, and discuss applications to imaging science and adaptive numerical solution of partial differential equations.
Compactly Supported Shearlets: Theory and Applications
HG D 16.2
16 September 2014
13:15-14:15 		Prof. Dr. Philipp Grohs
SAM ETH Zurich
Event Details
Speaker invited by Ralf Hiptmair
Geometric Data Representations
HG D 16.2
17 September 2014
16:15-17:15 		Prof. Dr. Jan Nordström
Linköping University
Event Details
Speaker invited by Remi Abgrall
Abstract During the last decade, stable high order finite difference methods and finite volume methods applied to initial-boundary-value-problems have been developed. The stability is due to the use of so-called summation-by-parts operators, penalty techniques for implementing boundary and interface conditions, and the energy method for proving stability. In this talk we discuss new aspects of this technique including the relation to the initial-boundary-value-problem. By reusing the main ideas behind the development, new time-integration procedures, boundary conditions, boundary procedures, multi-physics couplings and uncertainty quantification, have been derived. We will present the theory by analyzing simple examples and apply to very complex problems.
New Developments for Initial Boundary Value Problems at Linköping University
Y27 H 25
1 October 2014
16:15-17:15 		Dr. Alexander Veit
University of Chicago
Event Details
Speaker invited by Stefan Sauter
Abstract We propose a new method for the efficient approximation of a class of highly oscillatory weighted integrals where the oscillatory function depends on the frequency parameter $\omega \geq 0$, typically varying in a large interval. Our approach is based, for fixed but arbitrary oscillator, on the precomputation and low-parametric approximation of certain $\omega$-dependent prototype functions whose evaluation leads in a straightforward way to an approximation of the target integral. The difficulty that arises is that these prototype functions consist of oscillatory integrals and are itself oscillatory which makes them both difficult to evaluate and to approximate.
Here we use the quantized-tensor train (QTT) approximation method for functional $m$-vectors of logarithmic complexity in $m$ in combination with a cross-approximation scheme for TT tensors. This allows the accurate approximation and efficient storage of these functions for a wide range of grid and frequency parameters.
We will present theoretical results and numerical experiments that illustrate the efficiency of the QTT-based numerical integration scheme in one and several spatial dimensions.
Efficient computation of highly oscillatory integrals by using QTT tensor approximation
Y27 H 25
2 October 2014
10:15-11:15 		Prof. Dr. Habib Ammari
Ecole Normale Supérieure, Paris
Event Details
Speaker invited by Ralf Hiptmair
Abstract In this talk, we will suggest schemes for electrical sensing of objects by weakly electrical fish and for echolocation by bats. We will present recent results for shape identification and classification in electro-sensing using pulse form and waveform signals. We will also introduce an efficient and novel approach based on frequency-dependent shape descriptors for shape perception and classification in echolocation. Finally, we will apply the developed bio-inspired approaches in biomedical imaging in order to enhance the resolution, the robustness, and the specificity of tissue property imaging modalities.
Bio-inspired imaging for medical applications
HG D 16.2
15 October 2014
16:15-17:15 		Prof. Dr. Reinhold Schneider
TU Berlin
Event Details
Speaker invited by Christoph Schwab
Abstract Hierarchical Tucker tensor format (Hackbusch) and a particular case Tensor Trains (TT) (Tyrtyshnikov) have been introduced for high dimensional problems. The parametrization has been known in quantum physics as tensor network states. There are several ways to cast an approximate numerical solution into a variational framework. The Ritz Galerkin ansatz leads to an optimization problem on Riemannian manifolds. With this techniques, or in simplyfied form with a one-site DMRG one can be easily trapped into local minima. Although this problem can be avoided in combination with greedy techniques, we pursue a variational framework allowing concepts of compressive sensing. We obtain a soft shrinkage iteration scheme with in a Hierarchical SVD (HSVD) (or Vidal decomposition). We show that the iterates converge to the unique minimum of a convex optimization problem, even if the problem is ill-conditioned. We show a quasi-optimal error rate for the solution. The talk presents ongoing joint work with M. Bachmayr (RWTH Aachen).
Hierarchical tensor approximation of tensor network states by convex optimization
Y27 H 25
22 October 2014
16:15-17:15 		Prof. Dr. Boris Vexler
TU München
Event Details
Speaker invited by Christoph Schwab
Sparse Optimal Control Problems in Measure Spaces
Y27 H 25
29 October 2014
16:15-17:15 		Gerhard Kitzler
TU Wien
Event Details
Speaker invited by Ralf Hiptmair
Abstract We present a Discontinuous Galerkin method for the Boltzmann equation \[\frac{\partial f}{\partial t} + {\rm div}_x vf = Q(f)\] with the nonlinear Boltzmann collision operator Q(f). The distribution function f is approximated by a shifted Maxwellian in momentum times a polynomial in space and momentum. The test functions are chosen as polynomials in space and momentum. The first property leads to a good approximation close to equilibrium, while the second property ensures natural conservation of the physical quantities mass, momentum and energy. The focus of the talk is on an efficient algorithm for the collision operator. Therefore the solution is transformed between nodal, hierarchical and polar polynomial bases to reduce the inner integral operator to diagonal form.
Spectral polynomial discontinuous Galerkin method for the Boltzmann equation
Y27 H 25
5 November 2014
16:15-17:15 		Dr. Roman Andreev
RICAM Linz
Event Details
Speaker invited by Christoph Schwab
Abstract Tikhonov regularization is a popular device for the stable approximate resolution of linear ill-posed problems. The quality of the approximate solution depends on the regularization parameter and the uncertainty in the data. Under the optimal choice of the regularization parameter, the approximate solution converges to the exact one as the uncertainty is reduced; in order to obtain a convergence rate, however, additional assumptions on the exact solution are necessary. Such assumptions are called source conditions. In this talk we discuss variational source conditions that characterize the convergence rate in the low order regime.
Variational source conditions in inverse problems
Y27 H 25
12 November 2014
16:15-16:45 		Jackie Ma
Technische Universität Berlin
Event Details
Speaker invited by Philipp Grohs
Abstract The acquisition of Fourier data appears in many real world problems, such as magnetic resonance imaging, X-ray computed tomography, etc. The collected data, can be viewed as a collection of point samples of the Fourier transform of some object of interest, e.g. the human brain. Having these measurements, we are then left with the task to find an approximation of the original object. In this talk we discuss how this sampling and reconstruction task can be modeled using the so-called generalized sampling reconstruction method. In particular, we will present some benchmark results regarding the number of measurements that are needed in order to guarantee stable reconstructions. The results are presented for some compactly supported multiscale systems, such as wavelets and shearlets.
Reconstruction from Fourier Data by using Compactly Supported Multiscale Systems
Y27 H 25
12 November 2014
16:45-17:15 		Philipp Petersen
Technische Universität Berlin
Event Details
Speaker invited by Philipp Grohs
Abstract In this talk we discuss regularization techniques for the numerical solution of inverse scattering problems in two space dimensions. Assuming that the boundary of a scatterer is its most prominent feature, we exploit as model the class of cartoonlike functions. Since functions in this class are asymptotically optimally sparsely approximated by shearlet frames, we consider shearlets as a means for the regularization in a Tikhonov method. We examine both directly the nonlinear problem and a linearized problem obtained by the Born approximation technique. As problem classes we study the acoustic inverse scattering problem and the electromagnetic inverse scattering problem. Our approach introduces a sparse regularization for the nonlinear setting and we present a result describing the behavior of the local regularity of a scatterer under linearization, which shows that the linearization does not affect the sparsity of the problem. The analytical results are illustrated by numerical examples for the acoustic inverse scattering problem that highlight the effectiveness of this approach.
Regularization and Numerical Solution of the Inverse Scattering Problem Using Shearlet Frames
Y27 H 25
18 November 2014
17:00-18:00 		Mary Aprahamian
Manchester University
Event Details
Speaker invited by Siddhartha Mishra
Abstract In this talk we introduce the matrix unwinding function, which describes the discrepancy between a matrix and the principal logarithm of its exponential. We show that the unwinding function is instrumental in the derivation of correct identities involving logarithms and facilitates the understanding of other complex multivalued matrix functions, including inverse trigonometric functions. We also use it to study the matrix sign function. We give a numerical scheme for computing the matrix unwinding function and show how it can be used in conjunction with the scaling and squaring algorithm to compute the matrix exponential using the idea of argument reduction. (Joint work with Nick Higham)
The Matrix Unwinding Function
HG G 43
19 November 2014
16:15-17:15 		Prof. Dr. Kristof Cools
University of Nottingham
Event Details
Speaker invited by Ralf Hiptmair
Calderon Preconditioning in Computational Electromagnetics
Y27 H 25
26 November 2014
16:15-17:15 		Prof. Dr. Eric Cances
Ecole des Ponts and INRIA, Paris
Event Details
Speaker invited by Christoph Schwab
Abstract Electronic structure calculation has become an essential tool in chemistry, condensed matter physics, molecular biology, materials science, and nanosciences. It is also an inexhaustible source of exciting mathematical and numerical problems. In this talk, I will focus on Density Functional Theory and the Kohn-Sham model, which is to date the most widely used approach in electronic structure calculation, as it provides the best compromise between accuracy and computational efficiency. The Kohn-Sham model is a constrained optimization problem, whose Euler-Lagrange equations have the form of a coupled system of nonlinear elliptic eigenvalue problems. I will present some recent progress made in the numerical analysis of this model, which paves the road to high-fidelity numerical simulations (with a posteriori error bounds) of the electronic structure of large molecular systems. I will then discuss the difficult issue of coupling the Kohn-Sham model with coarser models in view of simulating even larger molecular systems, such as drug-protein complexes in solution.
Numerical methods for electronic structure calculation
Y27 H 25
3 December 2014
16:15-17:15 		Prof. Dr. John Maddocks
EPF Lausanne
Event Details
Speaker invited by Michel Chipot
Abstract It is now widely accepted that in addition to coding for proteins there is a second, mechanical, code in the sequence of DNA which controls biological function in various ways. Starting from large scale Molecular Dynamics simulation data I will discuss how to construct and parametrize coarse grain models of DNA at various scales. The models capture variations in shape and stiffness as a function of sequence in ways that can be tested against experiment. Mathematical techniques that arise include maximum parameter estimation, and symmetry breaking using Poincare-Melnikov functions in Hamiltonian ODE two-point boundary value problems.
Some Mathematical and Computational Techniques arising in the Multi-Scale Modelling of DNA mechanics
Y27 H 25
4 December 2014
12:15-13:15 		Prof. Dr. Athanasios Tzavaras
KAUST, Saudi Arabia
Event Details
Speaker invited by Siddhartha Mishra
Abstract Various problems in solid mechanics concern phenomena where discontinuous motions emerge. Such phenomena lie outside the traditional premiss of continuum modeling and their study raises questions at the interface of discrete and continuum modeling and poses challenges to the mathematical theory. In this talk we will review recent work on two specific examples: In the first part we will present results on nonuniqueness on the system of radial elasticity and the notion of singular induced from continuum solutions, which is a strengthening of the notion of weak solutions attempting to account for the surface energy required to open a cavity. The second part will consider the onset of localization and the formation of shear bands in high strain-rate plasticity of metals. Shear strain localization is tyically associated with ill-posedness of an underlying initial value problem, what has coined the term Hadamard-instability for its description in the mechanics literature. It should however be noted that while Hadamard instability indicates the catastrophic growth of oscillations around a mean state, it does not by itself explain the formation of coherent structures typically observed in localization. For a simple model capturing the essence of the mechanism of localization in metals we will construct self-similar solutions that describe the self-organization into a localized solution starting from well prepared data.
On problems with discontinuous motions in solid mechanics: shear bands and cavitation
HG G 19.2
10 December 2014
16:15-17:15 		Prof. Dr. David Ryckelynck
MINES Paristech, Evry, France
Event Details
Speaker invited by Remi Abgrall
Abstract Reduced-order models reveal common features between solutions of parametric partial differential equations (PDE). They aim to save computational time when modelling complex mechanical phenomena, as setting-up convenient nonlinear constitutive equations or boundary conditions for instance. The Garlerkin weak form of nonlinear reduced equations do not provide sufficient speed-up, mainly because the computation of the reduced-residual can’t be performed offline. Hence, this computation remains affected by the complexity of the original model. Hyper-reduction methods aim to generate reduced-order model whose complexity does not depend on the complexity of the original model by introducing a reduced integration domain (RID). This domain contains only few elements of the original mesh. We propose both an explicit hyper-reduced scheme and implicit hyper-reduced schemes applied to nonlinear mechanics of solid materials. The explicit approach aims to interpolate missing boundary conditions on the boundary of the RID. The implicit approach predicts the reduced coordinate of the displacement field by using balance conditions restricted to the RID. The RID is generated offline by aggregating the magic points of various reduced bases, depending on the physics involved in the original model. These magic points depend on the shape of the empirical modes by following the empirical interpolation method. The reduced-bases are obtained by using either: an a posteriori approach such as the snapshot POD method and the derivative extended POD method; or an a priori approach such as the APHR (A priori Hyper Reduction) method. In case of standard materials, an a posteriori error estimation is proposed by following the constitutive-relation-error method. We also develop a snapshotless approach to adapt the hyper-reduced approximation, without additional FE solution of the DPE.
Hyper-reduction in nonlinear mechanics of solid materials
Y27 H 25
12 December 2014
13:00-14:00 		Prof. Dr. Carsten Carstensen
Humboldt-Universität Berlin
Event Details
Speaker invited by Stefan Sauter
The Axioms of Adaptivity
Y27 H 25

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