Sökning: "periodic structure"

Visar resultat 1 - 5 av 123 avhandlingar innehållade orden periodic structure.

  1. 1. Nonlinear Approaches to Periodic Signal Modeling

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Emad Abd-Elrady; Uppsala universitet.; Uppsala universitet.; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cramer-Rao bounds; frequency estimation; identification; limit cycle; nonlinear systems; periodic signals; Wiener model structure; TECHNOLOGY Information technology Signal processing; TEKNIKVETENSKAP Informationsteknik Signalbehandling; Signal Processing; Signalbehandling;

    Sammanfattning : 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. LÄS MER

  2. 2. Scattering and propagation of electromagnetic waves in planar and curved periodic structures - applications to plane wave filters, plane wave absorbers and impedance surfaces

    Detta är en avhandling från Stockholm : Alfvénlaboratoriet

    Författare :Ola Forslund; KTH.; [2004]
    Nyckelord :electromagnetic scattering; periodic structure; frequency selectiove structure; frequency selective surface;

    Sammanfattning : The subject of this thesis is scattering of electromagneticwaves from planar and curved periodic structures. The problemspresented are solved in the frequency domain.Scattering from planar structures with two-dimensionalperiodic dependence of constitutive parameters is treated. LÄS MER

  3. 3. Acoustic excitation and transmission of lightweight structures

    Detta är en avhandling från Div. Engineering Acoustics, LTH

    Författare :Jonas Brunskog; Lund University.; Lunds universitet.; [2002]
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 4. Computer Simulations of Polymer Gels Structure, Dynamics, and Deformation

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Natasha Kamerlin; Uppsala universitet.; [2017]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; computer simulations; Brownian dynamics; polymer gel; microgel; spherical boundary conditions; hypersphere; core-shell; deswelling; mechanical properties; uniaxial elongation;

    Sammanfattning : This thesis presents the results of computer simulation studies of the structure, dynamics, and deformation of cross-linked polymer gels. Obtaining a fundamental understanding of the interrelation between the detailed structure and the properties of polymer gels is a challenge and a key issue towards designing materials for specific purposes. LÄS MER

  5. 5. Periodic Structures with Higher Symmetries: Analysis and Applications

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Fatemeh Ghasemifard; KTH.; [2018]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. LÄS MER