Search for dissertations about: "periodic"

Showing result 1 - 5 of 595 swedish dissertations containing the word periodic.

  2. 1. Algorithms and Library Software for Periodic and Parallel Eigenvalue Reordering and Sylvester-Type Matrix Equations with Condition Estimation

    Author : Robert Granat; Bo Kågström; Isak Jonsson; Volker Mehrmann; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; periodic eigenvalue problems; product eigenvalue problems; periodic Schur form; periodic eigenvalue reordering; periodic eigenspaces; parallel algorithms; Sylvester-type matrix equations; parallel eigenvalue reordering; condition estimation; Computer science; Datavetenskap;

    Abstract : This Thesis contains contributions in two different but closely related subfields of Scientific and Parallel Computing which arise in the context of various eigenvalue problems: periodic and parallel eigenvalue reordering and parallel algorithms for Sylvestertype matrix equations with applications in condition estimation.Many real world phenomena behave periodically, e. READ MORE

  4. 2. Analysis of Conformal Antennas and Periodic Structures

    Author : Silvia Raffaelli; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; method of moments; microstrip; corrugated surface; horn; Floquet; array; periodic; multilayer structure; finite difference time domain; dual-frequency; infinite; spectral domain analysis; conformal antenna;

    Abstract : In the last decades much attention has been paid to the design of high-performance antennas. Accurate control of the radiation properties is very important in electromagnetic engineering applications. READ MORE

  5. 3. Acoustic excitation and transmission of lightweight structures

    Author : Jonas Brunskog; Teknisk akustik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; point mobility; Lamb waves; wood.; Building construction; plate excitation; cavities; near-periodicity; nearly periodic; sound insulation; timber; structural acoustics; spatial Fourier transform; resilient device; prediction model; periodic; lightweight; ISO tapping machine; airborne noise; Building acoustics; impact noise; Byggnadsteknik;

    Abstract : In order to increase our knowledge of the sound transmission and radiation processes of lightweight wall and floor structures, theoretical models are needed. Detailed models may form a valuable tool. In lightweight floor structures, impact sound insulation is perhaps the most important property to consider. READ MORE

  6. 4. Nonlinear Approaches to Periodic Signal Modeling

    Author : Emad Abd-Elrady; Torsten Söderström; Torbjörn Wigren; Jonas Sjöberg; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cramer-Rao bounds; frequency estimation; identification; limit cycle; nonlinear systems; periodic signals; Wiener model structure; Signal processing; Signalbehandling; Signalbehandling; Signal Processing;

    Abstract : Periodic signal modeling plays an important role in different fields. The unifying theme of this thesis is using nonlinear techniques to model periodic signals. The suggested techniques utilize the user pre-knowledge about the signal waveform. This gives these techniques an advantage as compared to others that do not consider such priors. READ MORE

  7. 5. Twist-Symmetric Periodic Structures : Properties and Applications

    Author : Oskar Zetterström; Oscar Quevedo-Teruel; Martin Norgren; Nelson Fonseca; Jorge Ruiz-Cruz; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Abstract : In this thesis, periodic structures with higher symmetries symmetries are discussed. The main focus of the thesis is on twist symmetries. Importantly, the attractive properties of twist symmetries for the control of electromagnetic wave propagation are demonstrated. READ MORE