Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 47 for “"error estimate"”.
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A Flexible Galerkin Finite Element Method with an A Posteriori Discontinuous Finite Element Error Estimation for Hyperbolic Problems
… cost are included. Additionally, an a posteriori error estimate for the DGM applied to a two-dimensional hyperbolic partial differential equation is constructed. Several examples, both linear and nonlinear, indicating the effectiveness of the error estimate are included.
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An optimization framework for adaptive higher-order discretizations of partial differential equations on anisotropic simplex meshes
… framework that works with any localizable error estimate, handles any discretization order, permits arbitrarily oriented anisotropic elements, robustly treats irregular features, and inherits the versatility of the underlying discretization and error estimate. Given a discretization and any …
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Convergent finite element approximations for problems of near-incompressible and near-inextensible transversely isotropic linear elasticity
… finite element approximations are studied. The error estimate indicates the possibility of extensional locking; on the other hand, anisotropy, measured as the ratio of Young’s moduli in the fibre and transverse directions, plays a role in minimizing or even eliminating volumetric locking …
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An anisotropic adaptive method for the solution of 3-D inviscid and viscous compressible flows
… by the finite element method. An edge-based error estimate drives a mesh movement strategy that allows directional stretching and re-orientation of the grid with more mesh points introduced along those directions with rapidly changing gradients. The error estimate is built from a modified …
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Data Structure and Error Estimation for an Adaptive <i>p</i>-Version Finite Element Method in 2-D and 3-D Solids
… can reduce the magnitude of discretization error to the desired accuracy with minimum computational cost and computer resources. This study aims to 1) develop an efficient <i>p</i>-refinement procedure with a non-uniform <i>p</i> analysis capability for solving 2-D and 3-D elastostatic …
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ERROR BOUNDS OF COMPACT FINITE DIFFERENCE METHODS FOR SOME DISPERSIVE PDEs AND APPLICATIONS
… system in the subsonic regime. Proofs of error estimate based on energy methods and cut-off techniques are presented, and numerical results are reported for verification purposes. Conservative schemes and schemes with uniform error bounds are considered. Finally, we apply the 4cFD to …
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Adjoint Error Estimation for Elastohydrodynamic Lubrication
In this thesis, adjoint error estimation techniques are applied to complex elastohydrodynamic lubrication (EHL) problems. A functional is introduced, namely the friction, and justification is provided as to why this quantity, and hence its accuracy, is important. An iterative approach has been …
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Particle Spreading in a Simple Majda Flow and Eigenvalue Estimation Through a Cayley Transform
… variable. We consider methods for producing estimates of the eigenvalues of such operators. If such an operator can be written in the form H0 + H1 with H 1 relatively compact to H0, then the eigenvalues are asymptotically close to those of H0. This method does not, however, produce good error …
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Residual-based Discretization Error Estimation for Computational Fluid Dynamics
… and most difficult numerical approximation error to estimate is discretization error. Residual-based discretization error estimation methods are a category of error estimators that use an estimate of the source of discretization error and information about the specific application to …
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MergeArray and scalable, relaxed, concurrent, mergeable priority queues
… remove-min with expected worst-case rank-error of O(plogp) for p threads under common assumptions. I show experimental evidence that supports this rank-error estimate in practice as well as increased performance and scalability on a relaxed Minimum Spanning Tree benchmark compared to …
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Multidimensional Adaptive Quadrature Over Simplices
… defined over the unit hypercube and provides an error estimate that is used to drive a global subdivision strategy. The quadrature estimate is based on Lagrangian interpolation defined by using the vertices, edge nodes and interior points of a given simplex. The subdivision of a given simplex is …
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L^\infty Fehlerabschätzungen im Kontext geometrischer Evolutionsgleichungen
Mittels der Methode der gewichteten Normen wird eine Fehlerabschaetzung in L^\infty fuer eine Klasse nichtlinearer parabolischer Gleichungen nachgewiesen und auf die mean-curvature-flow Gleichung angewendet. Weiter wird eine Fehlerabschaetzung in L^2 fuer Willmore-flow auf drei Raumdimensionen …
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Error analysis for harmonic tracking algorithm using geometric control
… and dependent signals. This thesis describes the error analysis for time-dependent harmonic signal tracking in a particular control system using geometric controls. Here, we first discuss the basic setup and assumptions made in formulating the iterative scheme algorithm in geometric control. Next …
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Robustness of the achievable benchmark of care method
… when compared based on the root mean squared error estimate calculation. Cause for these results was found through examination of the sample distributions. Each distribution in the study was strongly, negatively, skewed revealing the benchmark provider comparison data to be uniform.</p>
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Salient features of contextual interference and knowledge of results
… and participants were either required to error estimate or given no instruction concerning estimation. A 2 (Acquisition Context) x 2 (Error Estimation Frequency) ANOVA was used to analyze absolute error (AE), variable error (VE) and a relative timing measure (AE(prop.)). The main effects …
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A C<sup>0</sup> Interior Penalty Method for the von Kármán Equations
… and establish the corresponding a priori error estimate by a fixed point argument. Numerical examples are presented that confirm the theoretical results.
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Discretization Error Estimation Using the Error Transport Equations for Computational Fluid Dynamics Simulations
… methods, and finite-element methods. Error introduced in the discretization process is called discretization error and defined as the difference between the exact solution to the discrete equations and the exact solution to the partial differential or integral equations. For most CFD …
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Application of Improved Truncation Error Estimation Techniques to Adjoint Based Error Estimation and Grid Adaptation
… Dynamics (CFD) are subject to discretization error, which is locally generated by truncation error. The discretization error is extremely difficult to properly estimate and this in turn leads to uncertainty over the quality of the numerical solutions obtained via CFD methods and the …
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Proper orthogonal decomposition & kriging strategies for design
… complicated responses whilst providing an error estimate of the predictor. However, it can be prohibitively expensive to construct a kriging model at high dimensions with a large number of sample points due to the cost associated with<br/>the maximum likelihood optimisation.<br/><br/>The …
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A finite element segregated method for thermo-chemical equilibrium and nonequilibrium hypersonic flows using adapted grids
… mesh adaptive scheme using an edge-based error estimate and an efficient mesh movement strategy. The accuracy of the numerical solution is continuously evaluated using a bound available from finite element theory. The Hessian (matrix of second derivatives) of a selected variable is …
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