Search for dissertations about: "Fourier coefficients"

Showing result 1 - 5 of 30 swedish dissertations containing the words Fourier coefficients.

  2. 1. Relations between functions from some Lorentz type spaces and summability of their Fourier coefficients

    Author : Aigerim Kopezhanova; Natasha Samko; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Lorentz spaces; Fourier series; Inequalities; Mathematics; Matematik; Mathematics; Matematik;

    Abstract : This Licentiate Thesis is devoted to the study of summability of the Fourier coefficients for functions from some Lorentz type spaces and contains three papers (papers A - C) together with an introduction, which put these papers into a general frame.Let $\Lambda_p(\omega),\;\; p>0,$ denote the Lorentz spaces equipped with the (quasi) norm$$\|f\|_{\Lambda_p(\omega)}:=\left(\int_0^1\left(f^*(t)\omega(t)\right)^p\frac{dt}{t}\right)^{\frac1p}$$for a function $f$ on [0,1] and with $\omega$ positive and equipped with some additional growth properties. READ MORE

  4. 2. Surface Characterization using Radiometric and Fourier Optical Methods

    Author : Peter Hansson; Arne Roos; Mikael Sjödahl; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; Radiometry; Fourier Optics; Surface Characterization; Topography; Reflectance; Color; Paper; Printing; Print quality; Gloss; Light scattering; Shape from shading; Photometric stereo; Optical motion compensation; Filtering; Wiener filter; Lamberts law; Image analysis; Image processing; Machine vision; Teknisk fysik; Engineering physics; Teknisk fysik;

    Abstract : This thesis treats static and dynamic surface characterization using radiometric and Fourier optical methods. A Fourier optical method has been developed for real time image processing in paper production and printing applications. READ MORE

  5. 3. Faraday modulation spectroscopy : Theoretical description and experimental realization for detection of nitric oxide

    Author : Jonas Westberg; Ove Axner; Gerard Wysocki; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Faraday modulation spectroscopy FAMOS ; Westberg-Wang-Axner WWA method; Fourier coefficients; Lineshape asymmetries; Nitric oxide NO ; fysik; Physics;

    Abstract : Faraday modulation spectroscopy (FAMOS) is a laser-based spectroscopic dispersion technique for detection of paramagnetic molecules in gas phase. This thesis presents both a new theoretical description of FAMOS and experimental results from the ultra-violet (UV) as well as the mid-infrared (MIR) regions. READ MORE

  6. 4. Optimization of Rotations in FFTs

    Author : Fahad Qureshi; Oscar Gustafsson; Mario Garrido; Jarmo Takala; Linköpings universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Discrete Fourier transform; Fast Fourier transform; twiddle factor multiplication;

    Abstract : The aims of this thesis are to reduce the complexity and increasethe accuracy of rotations carried out inthe fast Fourier transform (FFT) at algorithmic and arithmetic level.In FFT algorithms, rotations appear after every hardware stage, which are alsoreferred to as twiddle factor multiplications. READ MORE

  7. 5. Summability of Fourier transforms of functions from Lorentz spaces

    Author : Aigerim Kopezhanova; Lars-Erik Persson; Peter Wall; Erlan Nursultanov; Mikhael Goldman; Luleå tekniska universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

    Abstract : This PhD thesis is devoted to the study of relations between integrability properties of functions and summability properties of its Fourier coefficients and transforms. The relations are given in terms of generalized weighted Lorentz norms, where the weights have some additional growth properties. READ MORE