Sökning: "adjoint problem"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden adjoint problem.

1. 1. Data Assimilation in Fluid Dynamics using Adjoint Optimization

   Författare :Johan Lundvall; Vladimir Kozlov; Per Weinerfelt; Matts Karlsson; Anders Szepessy; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Data assimilation; Inverse problem; Adjoint optimization; Burgers equation; nonlinear; Landweber; Initial pressure; Euler flow; Applied mathematics; Tillämpad matematik;

   Sammanfattning : Data assimilation arises in a vast array of different topics: traditionally in meteorological and oceanographic modelling, wind tunnel or water tunnel experiments and recently from biomedical engineering. Data assimilation is a process for combine measured or observed data with a mathematical model, to obtain estimates of the expected data. LÄS MER

3. 2. Shape Optimization for Electromagnetic and Quasimagnetostatic Applications

   Författare :Per Jacobsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; shape optimization; continuum sensitivity; electromagnetic scattering; adjoint problem;

   Sammanfattning : This thesis uses a continuum formulation of sensitivity for shape optimization in two-dimensional microwave scattering and quasimagnetostatic problems. The continuum sensitivity is obtained by solving an appropriate adjoint problem. LÄS MER

4. 3. Adjoint-based aerodynamic shape optimization

   Författare :Olivier Amoignon; Martin Berggren; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Numerical Analysis; Numerisk analys;

   Sammanfattning : An adjoint system of the Euler equations of gas dynamics is derived in order to solve aerodynamic shape optimization problems with gradient-based methods. The derivation is based on the fully discrete flow model and involves differentiation and transposition of the system of equations obtained by an unstructured and node-centered finite-volume discretization. LÄS MER

5. 4. Direct and Inverse Methods for Waveguides and Scattering Problems in the Time Domain

   Författare :Erik Abenius; Per Lötstedt; Mats Gustafsson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; time-domain; FDTD; finite-element; hybrid; thin sheet; waveguide; PML; inverse scattering; adjoint; gradient-based; minimization; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : Numerical simulation is an important tool in understanding the electromagnetic field and how it interacts with the environment. Different topics for time-domain finite-difference (FDTD) and finite-element (FETD) methods for Maxwell's equations are treated in this thesis. LÄS MER

7. 5. Analysis, Control, and Design Optimization of Engineering Mechanics Systems

   Författare :Esubalewe Lakie Yedeg; Martin Berggren; Eddie Wadbro; Anton Evgrafov; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Topology optimization; Helmholtz equation; acoustic impedance; anisotropic filter; thin structures; finite element method; Nitsche-type method; interface problem; Optimal control; adjoint method; business data processing; administrativ databehandling;

   Sammanfattning : This thesis considers applications of gradient-based optimization algorithms to the design and control of some mechanics systems. The material distribution approach to topology optimization is applied to design two different acoustic devices, a reactive muffler and an acoustic horn, and optimization is used to control a ball pitching robot. LÄS MER