Sökning: "Waves and Signals"

Visar resultat 6 - 10 av 65 avhandlingar innehållade orden Waves and Signals.

  1. 6. High frequency scattering and spectral methods

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

    Sammanfattning : 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. LÄS MER

  3. 7. Light scattering and absorption in tissue - models and measurements

    Författare :Annika M K Enejder; Atomfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tissue optical properties; Light absorption; Fluorescence spectroscopy; Atomic and molecular physics; NIR spectroscopy; Fysicumarkivet A:1997:Enejder; Light scattering; Atom- och molekylärfysik;

    Sammanfattning : In this work a number of theoretical models, describing light propagation in matter, have been applied to and developed for the examination of tissue. The aim was to model the light scattering and absorption in tissue in order to improve the understanding of underlying mechanisms of laser-based diagnostics and treatment modalities utilised for cancer and cardiovascular diseases. LÄS MER

  4. 8. Active Control of Noise in Ventilation Systems : Analysis and Experiments

    Författare :Martin Larsson; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In many kinds of buildings, the ventilation system constitute a well known source of broadband noise. Traditionally, duct born noise is attenuated using passive resistive silencers which produce a high level of attenuation over a broad frequency range. However, they tend to become large and bulky if designed for low frequency attenuation. LÄS MER

  5. 9. High resolution time-frequency representations

    Författare :Isabella Reinhold; Statistical Signal Processing Group; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; time-frequency analysis; non-stationary signals; multi-component signals; IF estimation; reassignment;

    Sammanfattning : Non-stationary signals are very common in nature, e.g. sound waves such as human speech, bird song and music. It is usually meaningful to describe a signal in terms of time and frequency. LÄS MER

  7. 10. Sensitivity Analysis and Material Parameter Estimation using Electromagnetic Modelling

    Författare :Therese Sjödén; Sven Nordebo; Börje Nilsson; Margaret Cheney; Linnéuniversitetet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER