Sökning: "Uncertainty quantification"

Visar resultat 1 - 5 av 83 avhandlingar innehållade orden Uncertainty quantification.

1. 1. Multiscale Methods and Uncertainty Quantification

   Författare :Daniel Elfverson; Axel Målqvist; Frédéric Legoll; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multiscale methods; finite element method; discontinuous Galerkin; Petrov-Galerkin; a priori; a posteriori; complex geometry; uncertainty quantification; multilevel Monte Carlo; failure probability; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : In this thesis we consider two great challenges in computer simulations of partial differential equations: multiscale data, varying over multiple scales in space and time, and data uncertainty, due to lack of or inexact measurements.We develop a multiscale method based on a coarse scale correction, using localized fine scale computations. LÄS MER

3. 2. Reliable Uncertainty Quantification in Statistical Learning

   Författare :David Widmann; Fredrik Lindsten; Dave Zachariah; Erik Sjöblom; Dino Sejdinovic; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Reliability; Calibration; Uncertainty; Probabilistic Model; Prediction; Julia; Machine learning; Maskininlärning;

   Sammanfattning : Mathematical models are powerful yet simplified abstractions used to study, explain, and predict the behavior of systems of interest. This thesis is concerned with their latter application as predictive models. LÄS MER

4. 3. Uncertainty Quantification and Numerical Methods for Conservation Laws

   Författare :Per Pettersson; Jan Nordström; Gianluca Iaccarino; Gunilla Kreiss; Rémi Abgrall; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; uncertainty quantification; polynomial chaos; stochastic Galerkin methods; conservation laws; hyperbolic problems; finite difference methods; finite volume methods; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : Conservation laws with uncertain initial and boundary conditions are approximated using a generalized polynomial chaos expansion approach where the solution is represented as a generalized Fourier series of stochastic basis functions, e.g. orthogonal polynomials or wavelets. LÄS MER

5. 4. Uncertainty quantification for time varying quantities in turbulent flows

   Författare :Donnatella Xavier; Philipp Schlatter; Saleh Rezaeiravesh; Ricardo Vinuesa; David Moxey; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; uncertainty; variance estimator; autoregressive models; turbulence; computational fluid dynamics; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : Quantification of uncertainty in results is crucial in both experiments and simulations of turbulence, yet this practice is notably underutilized. This thesis project delves into statistical tools within the framework of uncertainty quantification to systematically quantify uncertainties that occur in the time varying quantities of turbulence. LÄS MER

7. 5. Towards Changeability Quantification for Product-Service Systems Design

   Författare :Raj Jiten Machchhar; Alessandro Bertoni; Johan Wall; Fredrik Elgh; Blekinge Tekniska Högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Changeability quantification; early design; Uncertainty; Value robustness; Operational Scenario; Product-Service Systems; Systems Engineering.; Maskinteknik; Mechanical Engineering;

   Sammanfattning : Tough competition and volatile global markets have pushed the manufacturing industries to develop solutions more customer-centric with optimal utilization of resources. One of the key reasons behind developing a customer-centric solution is the increased customer value that imparts a competitive edge to the manufacturing industries, eventually leading them to sustain their businesses. LÄS MER