Sökning: "gradient method"

Visar resultat 21 - 25 av 424 avhandlingar innehållade orden gradient method.

1. 21. Inverse and optimization problems in electromagnetics -- a finite-element method perspective

   Författare :JOHAN WINGES; Chalmers tekniska högskola; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; microwave measurements; computational electromagnetics; finite element method; optimization; inductive power transfer; compressed sensing; wireless power; brick-tetrahedron hybrid; parameter estimation; inverse problems;

   Sammanfattning : In this thesis, a selection of inverse and optimization problems are studied where the finite element method (FEM) serves as a comprehensive tool to solve electromagnetic field problems that lack an analytic solution. The inverse problems are typically formulated in terms of an optimization problem where the misfit between a measurement and the corresponding result of a computational model is minimized. LÄS MER

3. 22. Structure of Zero Pressure Gradient High Reynolds Number Turbulent Boundary Layers

   Författare :Murat Tutkun; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fourier decomposition.; proper orthogonal decomposition; large scale structures; Turbulent boundary layers; zero pressure gradient; wind tunnel; calibration; cross-correlations; hot-wire; two-point correlations; high Reynolds number;

   Sammanfattning : This thesis presents part of the large research program funded by the European Commission calledWallturb: A European synergy for the assessment of wall turbulence. The main aim of this researchprogram is to create new experimental and numerical databases on the characteristics of turbulent wall-bounded flows, especially turbulent boundary layers. LÄS MER

4. 23. Pulsed Field Gradient NMR Studies of Diffusion in Polymer Gels

   Författare :Diana Bernin; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diffusion; gel; alginate; pulsed field gradient NMR; 19F NMR; cellulose; 1H NMR; dendrimer; biomaterial; mass transport;

   Sammanfattning : Soft biomaterials, such as gels, play an important role in different kinds of products and applications, in particular in drug delivery systems, health care products, and food. Polymer gel's great ability to control mass transport is applied on e.g. the uptake of liquids in diapers. LÄS MER

5. 24. Optimization for scattering and radiation problems based on a stable FEM-FDTD hybrid method

   Författare :Tomas Halleröd; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finite-difference time-domain; finite element method; array antennas; electric and magnetic losses; pattern synthesis; shape and material optimization; explicit-implicit time-stepping; scattering;

   Sammanfattning : In this thesis, a stable hybrid method combining the finite-elementmethod (FEM) and the finite-difference time-domain (FDTD) scheme forMaxwell's equations in two dimensions with both electric and magneticlosses is presented. It combines the flexibility of the FEM with theefficiency of the FDTD scheme. LÄS MER

7. 25. A Simulation-Based Optimisation Method for PLC Systems

   Författare :Bo Svensson; Bengt Lennartson; Rolf Bernhardt; Högskolan Väst; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Simulation based optimisation; Virtual manufacturing; Industrial control system; PLC; Continuous simulation; Parameter tuning; Optimisation methods; Manufacturing and materials engineering; Produktions- och materialteknik;

   Sammanfattning : Tuning of process parameters such as time constants, cam values, velocities and robot paths, in order to increase capacity utilisation, is today a challenging manual on-line task in many automated manufacturing systems. On-line methods interfere with production and will cause unwanted downtime, which indeed reduces capacity utilisation. LÄS MER