Institut für Numerische Simulation (INS): Browsing Institut für Numerische Simulation (INS) by Title
Now showing items 72-91 of 153
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Kernel-based reconstructions for parametric PDEs
Kempf, Rüdiger; Wendland, Holger; Christian, Rieger (2018-03)In uncertainty quantification, an unknown quantity has to be reconstructed which depends typically on the solution of a partial differential equation. This partial differential equation itself may depend on parameters, ... -
Kernel-based stochastic collocation for the random two-phase Navier-Stokes equations
Michael Griebel; Christian Rieger; Peter Zaspel (2018-10)In this work, we apply stochastic collocation methods with radial kernel basis functions for an uncertainty quantification of the random incompressible two-phase Navier–Stokes equations. Our approach is nonintrusive and ... -
Knowledge discovery assistants for crash simulations with graph algorithms and energy absorption features
Pakiman, Anahita; Garcke, Jochen; Schumacher, Axel (2022)We propose the representation of data from finite element car crash simulations in a graph database to empower analysis approaches. The industrial perspective of this work is to narrow the gap between the uptake of modern ... -
Line search algorithms for locally Lipschitz functions on Riemannian manifolds
Hosseini, Somayeh; Huang, Wen; Yousefpour, Rohollah (2016-11)This paper presents line search algorithms for finding extrema of locally Lipschitz functions defined on Riemannian manifolds. To this end we generalize the so-called Wolfe conditions for nonsmooth functions on Riemannian ... -
Localized Coulomb descriptors for the Gaussian Approximation Potential
Barker, James; Bulin, Johannes; Hamaekers, Jan; Mathias, Sonja (2016-02)We introduce a novel class of localized atomic environment representations, based upon the Coulomb matrix. By combining these functions with the Gaussian approximation potential approach, we present LC-GAP, a new system ... -
Low-rank approximation of continuous functions in Sobolev spaces with dominating mixed smoothness
Griebel, Michael; Harbrecht, Helmut; Schneider, Reinhold (2022-03)Let Ω<sub><em>i</em></sub> ⊂ R<em><sup>n<sub>i</sub></sup></em> , <em>i</em> = 1, . . . , <em>m</em>, be given domains. In this article, we study the low-rank approximation with respect to L<sup>2</sup>(Ω<sub>1</sub> × · ... -
Low-rank approximation to heterogeneous elliptic problems
Li, Guanglian (2017-03)In this work, we investigate the low-rank approximation of elliptic problems in heterogeneous media by means of Kolmogrov <em>n</em>-width and asymptotic expansion. This class of problems arises in practical applications ... -
A mass-conserving sparse grid combination technique with biorthogonal hierarchical basis functions for kinetic simulations
Pollinger, Theresa; Rentrop, Johannes; Pflüger, Dirk; Kormann, Katharina (2022-09)The exact numerical simulation of plasma turbulence is one of the assets and challenges in fusion research. For grid-based solvers, sufficiently fine resolutions are often unattainable due to the curse of dimensionality. ... -
Maximum approximated likelihood estimation
Griebel, Michael; Heiss, Florian; Oettershagen, Jens; Weiser, Constantin (2019-08)Empirical economic research frequently applies maximum likelihood estimation in cases where the likelihood function is analytically intractable. Most of the theoretical literature focuses on maximum simulated likelihood ... -
Molecular dynamics simulations of boron-nitride nanotubes embedded in amorphous Si-B-N
Griebel, Michael; Hamaekers, Jan (2005-05)In this article, we examine the elastic properties of boron-nitride nanotubes, which are embedded in amorphous silicon-boron-nitride ceramics. We employ molecular dynamics simulations using the Parrinello-Rahman approach. ... -
Molecular dynamics simulations of the influence of chemical cross-links on the elastic moduli of polymer-carbon nanotube composites
Griebel, Michael; Hamaekers, Jan; Wildenhues, Ralf (2005-06)In this article we compare the Young modulus of polyethylene carbon nanotube composites with chemical cross-links between the nanotube and the polyethylene matrix to the modulus of a composite with weak non-bonded ... -
Molecular dynamics simulations of the mechanical properties of polyethylene-carbon nanotube composites
Griebel, Michael; Hamaekers, Jan (2005-05) -
Multi-resolution dynamic mode decomposition for early damage detection in wind turbine gearboxes
Climaco, Paolo; Garcke, Jochen; Iza-Teran, Rodrigo (2021-10)We introduce an approach for damage detection in gearboxes based on the analysis of sensor data with the multi-resolution dynamic mode decomposition (mrDMD). The application focus is the condition monitoring of wind turbine ... -
Multiscale approximation and reproducing kernel Hilbert space methods
Griebel, Michael; Rieger, Christian; Zwicknagl, Barbara (2013)We consider reproducing kernels <em>K</em> : Ω x Ω → ℝ in multiscale series expansion form, i.e., kernels of the form <em>K</em> (<em>x</em>, <em>y</em>) = ∑<sub>ℓ∈ℕ</sub>λ<sub>T ... -
Multiscale partition of unity
Henning, Patrick; Morgenstern, Philipp; Peterseim, Daniel (2013-12)We introduce a new Partition of Unity Method for the numerical homogenization of elliptic partial differential equations with arbitrarily rough coefficients. We do not restrict to a particular ansatz space or the existence ... -
Multiscale Petrov-Galerkin method for high-frequency heterogeneous Helmholtz equations
Brown, Donald L.; Gallistl, Dietmar; Peterseim, Daniel (2015-12)This paper presents a multiscale Petrov-Galerkin finite element method for time-harmonic acoustic scattering problems with heterogeneous coefficients in the high-frequency regime. We show that the method is pollution-free ... -
Multiscale simulation of ion migration for battery systems
Neuen, Christian; Griebel, Michael; Hamaekers, Jan (2012-11)In this paper we describe a multi-scale approach to ion migration processes, which involves a bridging from the atomic scale to the macroscopic scale. To this end, the diffusion coefficient of a material i.e. a macroscopic ... -
Multiscale simulation of polymeric fluids using the sparse grid combination technique
Rüttgers, Alexander; Griebel, Michael (2017-10)We present a computationally efficient sparse grid approach to allow for multiscale simulations of non-Newtonian polymeric fluids. Multiscale approaches for polymeric fluids often involve model equations of high dimensionality. ... -
Multiscale simulations of three-dimensional viscoelastic flows in a square-square contraction
Griebel, Michael; Rüttgers, Alexander (2015-03)We apply the multiscale FENE model to a 3D square-square contraction flow problem and to two 2D benchmark experiments. For this purpose, we couple the stochastic Brownian configuration field method (BCF) with our fully ... -
Multivariate Haar systems in Besov function spaces
Peter Oswald (2020-03)We determine all cases for which the d-dimensional Haar wavelet system <em>H<sup>d</sup></em> on the unit cube <em>I<sup>d</sup></em> is a conditional or unconditional Schauder basis in the classical isotropic Besov function ...