Institut für Numerische Simulation (INS): Browsing Institut für Numerische Simulation (INS) by Title
Now showing items 65-84 of 153
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Haar system as Schauder basis in Besov spaces: the limiting cases for 0 < p ≤ 1
Peter Oswald (2018-09)We show that the <em>d</em>-dimensional Haar system <em>H<sup>d</sup></em> on the unit cube <em>I<sup>d</sup></em> is a Schauder basis in the classical Besov space B<em><sup>s</sup><sub>p,q,1</sub></em>(<em>I<sup>d</sup></em>), ... -
Hyperbolic cross approximation in infinite dimensions
Dũng, Dinh; Griebel, Michael (2015)We give tight upper and lower bounds of the cardinality of the index sets of certain hyperbolic crosses which reflect mixed Sobolev-Korobov-type smoothness and mixed Sobolev-analytic-type smoothness in the infinite-dimensional ... -
In-situ Estimation of Time-averaging Uncertainties in Turbulent Flow Simulations
Rezaeiravesh, Saleh; Gscheidle, Christian; Peplinski, Adam; Garcke, Jochen; Schlatter, Philipp (2022)The statistics obtained from turbulent flow simulations are generally uncertain due to finite time averaging. The techniques available in the literature to accurately estimate these uncertainties typically only work in an ... -
Incremental kernel based approximations for Bayesian inverse problems
Rieger, Christian (2018-05)We provide an interpretation for the covariance of the predictive process of Bayesian Gaussian process regression as reproducing kernel of a subset of the Cameron Martin space of the prior. We demonstrate that this ... -
Inexact additive Schwarz solvers for hp-FEM discretizations in three dimensions
Beuchler, Sven (2011-07)In this paper, a boundary value problem of second order in three space dimensions is discretized by means of the <em>hp</em>-version of the finite element method. The system of linear algebraic equations is solved by the ... -
Intraday foreign exchange rate forecasting using sparse grids
Garcke, Jochen; Gerstner, Thomas; Griebel, Michael (2010-11)We present a machine learning approach using the sparse grid combination technique for the forecasting of intraday foreign exchange rates. The aim is to learn the impact of trading rules used by technical analysts just ... -
Iterated Landweber method for radial basis functions interpolation with finite accuracy
Rieger, Christian (2018-05)We consider the reconstruction of a function stemming from a reproducing kernel Hilbert space using data which is perturbed by a deterministic error of maximal size ε<sub>∞</sub>. The accuracy ε<sub>∞</sub> ... -
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 ...