Sökning: "wavelet"

Visar resultat 31 - 35 av 104 avhandlingar innehållade ordet wavelet.

  1. 31. Temporal and Wavelet Characteristics of Initial Breakdown and Narrow Bipolar Pulses of Lightning Flashes

    Författare :Mona Riza Mohd Esa; Vernon Cooray; Mahbubur Rahman; Farhad Rachidi; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Initial breakdown; Lightning flash; Narrow bipolar pulse; Temporal-Wavelet characterization; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

    Sammanfattning : Temporal and wavelet characteristics of initial breakdown pulses are meticulously studied especially during the earliest moment of lightning events. Any possible features during the earliest moment that may exist which lead to either negative cloud-to-ground (CG), positive cloud-to-ground, cloud or isolated breakdown flashes in Sweden are investigated. LÄS MER

  3. 32. Multivariate analysis and wavelet transform analysis of diesel engine combustion noise

    Författare :Villarroel Grover Zurita; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk akustik; Engineering Acoustics;

    Sammanfattning : .... LÄS MER

  4. 33. Hilbert space frames and bases : a comparison of Gabor and wavelet frames and applications to multicarrier digital communications

    Författare :Niklas Grip; Luleå tekniska universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Sammanfattning : Several signal processing applications today are based on the use of different transforms. The signals under consideration are written as a linear combination (or series) of some predefined set of functions. Traditionally, orthogonal bases have been used for this purpose, for example, in the discrete Fourier transform. LÄS MER

  5. 34. Modeling RF waves in hot plasmas using the finite element method and wavelet decomposition : Theory and applications for ion cyclotron resonance heating in toroidal plasmas

    Författare :Pablo Vallejos; Thomas Jonsson; Torbjörn Hellsten; Philippe Lamalle; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Fusion energy has the potential to provide a sustainable solution for generating large quantities of clean energy for human societies. The tokamak fusion reactor is a toroidal device where the hot ionized fuel (plasma) is confined by magnetic fields. Several heating systems are used in order to reach fusion relevant temperatures. LÄS MER

  7. 35. WAVELET NOISE REDUCTION AND VASCULAR WATER TRANSPORT MODELLING : APPLICATIONS TO DIFFUSION AND PERFUSION MRI

    Författare :Adnan Bibic; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; cerebral blood flow; perfusion; diffusion; arterial spin labelling; wavelets; filtering; denoising; blood-brain barrier; permeability; Fysicumarkivet A:2018:Bibic;

    Sammanfattning : Magnetic resonance imaging (MRI) is a powerful medical imaging technique, used to detect and characterise a range of diseases and conditions. It is based on the use of a strong static magnetic field in combination with magnetic field gradients and pulsed radiofrequency electromagnetic fields to visualise various organs and structures in the body according to their morphology or function. LÄS MER