Search for dissertations about: "time-domain electromagnetic"

Showing result 1 - 5 of 52 swedish dissertations containing the words time-domain electromagnetic.

2. 1. Hybrid Solvers for the Maxwell Equations in Time-Domain

   Author : Fredrik Edelvik; Per Lötstedt; Jan Hesthaven; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Maxwell s equations; time-domain; finite volume methods; finite element methods; hybrid solver; dispersive materials; thin wires; Beräkningsvetenskap; Scientific Computing;

   Abstract : The most commonly used method for the time-domain Maxwell equations is the Finite-Difference Time-Domain method (FDTD). This is an explicit, second-order accurate method, which is used on a staggered Cartesian grid. The main drawback with the FDTD method is its inability to accurately model curved objects and small geometrical features. READ MORE

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

   Author : Erik Abenius; Per Lötstedt; Mats Gustafsson; Uppsala universitet; []
   Keywords : 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;

   Abstract : 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. READ MORE

5. 3. Three-Dimensional Modelling and Inversion of DC resistivity and Time Domain EM data using Multi-Resolution Framework

   Author : Jingyu Gao; Thorkild Maack Rasmussen; Maxim Smirnov; Bülent Tezkan; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; DC Resistivity; time-domain electromagnetic; forward modelling; data inversion; Prospekteringsgeofysik; Exploration Geophysics;

   Abstract : 3-D forward modelling and inversion techniques play an important role in data interpretation, but they are still computationally challenging tasks. Therefore, this thesis aims to improve forward modelling and inversion performance using novel multi-resolution (MR) grid approach. READ MORE

6. 4. Transient electromagnetic pulse propagation in temporally dispersive materials

   Author : Igor Egorov; Institutionen för elektro- och informationsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Green functions; direct scattering; time domain; wave propagation; bi-gyrotropic; chiral; bi-isotropic; Forerunner; precursor; Green dyadics; Electronics and Electrical technology; Elektronik och elektroteknik;

   Abstract : This thesis treats the problem of transient electromagnetic pulse propagation in temporally dispersive media. The analysis is performed using time-domain techniques. In particular, the dispersive wave splitting which decouples the Maxwell equations both in vacuum and inside the medium is utilized. READ MORE

7. 5. Time-Domain Inverse Electromagnetic Scattering using FDTD and Gradient-based Minimization

   Author : Erik Abenius; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; inverse scattering fdtd minimization adjoint ;

   Abstract : The thesis addresses time-domain inverse electromagneticscattering for determining unknown characteristics of an objectfrom observations of the scattered .eld. Applications includenon-destructive characterization of media and optimization ofmaterial properties, for example the design of radar absorbingmaterials. READ MORE