Sökning: "Fourier multipliers"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Fourier multipliers.

1. 1. Some new Fourier multiplier results of Lizorkin and Hörmander types

   Författare :Lyazzat Sarybekova; Michael L. Goldman; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fourier multipliers; Lizorkin theorem; Hörmander theorem; regular system; Mathematics; Matematik; Mathematics; Matematik;

   Sammanfattning : This PhD Thesis is devoted to the study of Fourier series and Fourier transform multipliers and it contains four papers (papers A - D) together with an introduction, which put these papers into a general frame. This extensive introduction can also be seen as an independent description of this important area including the historical development and the most important results. LÄS MER

3. 2. Optimization of Rotations in FFTs

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

   Sammanfattning : 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. LÄS MER

4. 3. Some new Lizorkin multiplier theorems for Fourier series and transforms

   Författare :Lyazzat Sarybekova; Luleå tekniska universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik;

   Sammanfattning : This Licentiate Thesis is devoted to the study of Fourier series and Fourier transform multipliers and contains three papers (papers A - C) together with an introduction, which put these papers into a general frame. In paper A a generalization of the Lizorkin theorem on Fourier multipliers is proved. LÄS MER

5. 4. Invariant Subspaces in Spaces of Analytic Functions

   Författare :Ali Abkar; Matematik (naturvetenskapliga fakulteten); []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; functional analysis; Series; Fourier analysis; weighted Bergman space.; super-biharmonic function; quasi-Banach space of analytic functions; index; multiplier module homomorphism; multiplier; Banach space of analytic functions; hyperinvariant subspace; Serier; fourieranalys; funktionsanalys;

   Sammanfattning : Let D be a finitely connected bounded domain with smooth boundary in the complex plane. We first study Banach spaces of analytic functions on D . The main result is a theorem which converts the study of hyperinvariant subspaces on multiply connected domains into the study of hyperinvariant subspaces on domains with fewer holes. LÄS MER

7. 5. ASIC Implementation of a Delayless Acoustic Echo Canceller: Architecture and Arithmetic

   Författare :Anders Berkeman; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; Signalbehandling; Digital Arithmetic; Acoustic Echo Cancellation; Hardware Implementation; Digital ASIC Design; Digital Signal Processing;

   Sammanfattning : Application specific digital signal processors are superior compared to standard digital signal processors in a number of application fields, mainly due to high throughput and low power consumption traded for flexibility. This thesis deals with two areas related to hardware implementation of custom digital signal processors: design methodology and efficient implementation of arithmetic circuits. LÄS MER