Search for dissertations about: "vågor och signaler"

Showing result 1 - 5 of 12 swedish dissertations containing the words vågor och signaler.

2. 1. Estimation of electromagnetic material properties with application to high-voltage power cables

   Author : Yevhen Ivanenko; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material losses; power cables; cylindrical multipole expansion; Herglotz functions; convex optimization; sum rules; Waves and Signals; Vågor och signaler;

   Abstract : Efficient design of high-voltage power cables is important to achieve an economical delivery of electric power from wind farms and power plants over the very long distances as well as the overseas electric power. The main focus of this thesis is the investigation of electromagnetic losses in components of high-voltage power cables. READ MORE

4. 2. Sensitivity Analysis and Material Parameter Estimation using Electromagnetic Modelling

   Author : Therese Sjödén; Sven Nordebo; Börje Nilsson; Margaret Cheney; Linnéuniversitetet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sensitivity analysis; material parameter; Fisher information; Cramér-Rao bound; electromagnetic modelling; grain angle; wood; electrical impedance tomography; inverse problems; känslighetsanalys; estimering; materialparameter; Fisher- information; Cramér-Rao-gränsen; elektromagnetisk modellering; fibervinkel; trä; elektrisk impedanstomografi; inversa problem; Waves; Signals and Systems; Vågor; signaler och system;

   Abstract : Estimating parameters is the problem of finding their values from measurements and modelling. Parameters describe properties of a system; material, for instance, are defined by mechanical, electrical, and chemical parameters. Fisher information is an information measure, giving information about how changes in the parameter effect the estimation. READ MORE

5. 3. Optimization and Physical Bounds for Passive and Non-passive Systems

   Author : Yevhen Ivanenko; Sven Nordebo; Börje Nilsson; Mats Gustafsson; Mariana Dalarsson; Aaron Welters; Linnéuniversitetet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Convex optimization; physical bounds; Herglotz functions; quasi-Herglotz functions; passive systems; non-passive systems; approximation; absorption in lossy media; Waves; Signals and Systems; Vågor; signaler och system;

   Abstract : Physical bounds in electromagnetic field theory have been of interest for more than a decade. Considering electromagnetic structures from the system theory perspective, as systems satisfying linearity, time-invariance, causality and passivity, it is possible to characterize their transfer functions via Herglotz functions. READ MORE

6. 4. High frequency scattering and spectral methods

   Author : Imad Akeab; Sven-Erik Sandström; Andreas Asheim; Linnéuniversitetet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Waves; Signals and Systems; Vågor; signaler och system;

   Abstract : This thesis consists of five parts. The first part is an introduction with references to some recent work on 2D electromagnetic scattering problems at high frequencies. It also presents the basic integral equation types for impenetrable objects and the standard elements of the method of moments. READ MORE

7. 5. Thick Frequency Selective Structures

   Author : Björn Widenberg; Institutionen för elektro- och informationsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustics; Elektromagnetism; optik; akustik; optics; Electromagnetism; Energy Saving Window; Radome; Finite Elemente Method; Frequency Selective Structure; Mode Matching Technique;

   Abstract : This thesis presents a new method that can handle a general thick Frequency Selective Structure (FSS), that consists of an arbitrary number of aperture layers and dielectric layers. The method is based on the Mode Matching Technique (MMT) and the finite element method (FEM). The thesis consists of a General Introduction and five scientific papers. READ MORE