Sökning: "linear dynamics"

Visar resultat 1 - 5 av 506 avhandlingar innehållade orden linear dynamics.

  1. 1. Lattice dynamics : From fundamental research to practical applications

    Författare :Johan Tidholm; Igor A. Abrikosov; Olle Hellman; Ferenc Tasnadi; Gerd Steinle-Neumann; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The reason to perform calculations in material science usually falls into one of two categories: to predict or explain the origin of material properties. This thesis covers first-principle calculations for solids at extreme conditions, from both of the two mentioned categories. LÄS MER

  2. 2. Theoretical perspectives on ultrafast and non-linear spectroscopy

    Författare :Emil Vinas Boström; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Non-linear optics; Ultrafast dynamics; Non-equilibrium Green s functions; Density functional theory; Multi-photon absorption; Second harmonic generation; Desorption dynamics; Auger decay; Charge-separation dynamics; Quantum Zeno effect; Fysicumarkivet A:2018:Vinas Boström;

    Sammanfattning : In this thesis we discuss a theoretical description of ultrafast and non-linear spectroscopy. Due to the high intensities and ultrashort pulse durations involved in such experiments, it is necessary to use an explicitly time-dependent formalism. LÄS MER

  3. 3. Population and Community Dynamics in Variable Environments

    Författare :Jörgen Ripa; Evolutionär ekologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dispersal; Moran effect; linear dynamics; synchrony; power spectrum; autocorrelation; extinction risk; population dynamics; environmental stochasticity; migration; stochastic modelling; Ecology; Ekologi;

    Sammanfattning : All natural populations fluctuate in space and time. These fluctuations are a result of internal dynamic processes, and of a variable environment. LÄS MER

  4. 4. Modelling and Experimental Verification of Direct Drive Wave Energy Conversion : Buoy-Generator Dynamics

    Författare :Mikael Eriksson; Mats Leijon; Jan Isberg; Arne Wolfbrandt; Kim Nielsen; Uppsala universitet; []
    Nyckelord :Engineering physics; Wave energy; Potential wave theory; Linear generator; Simulations; Experiments; Point absorber; FEM; Equivalent circuit theory; Teknisk fysik; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : This thesis is focused on development of models and modelling of a wave energy converter in operation. Through the thesis linear potential wave theory has been used to describe the wave-buoy interaction. The differences lie in the generator models, in the simplest model the generator is a mechanical damper characterized by a damping factor. LÄS MER

  5. 5. Fractional Calculus and Linear Viscoelasticity in Structural Dynamics

    Författare :Mikael Enelund; Chalmers University of Technology; []
    Nyckelord :linear viscoelasticity; convolution integrals; anisotropy; structural modeling; finite elements; material damping; time integration; internal variables; relaxation; fractional calculus; creep; Mittag-Leffler functions;

    Sammanfattning : The use of linear viscoelasticity together with fractional calculus in time-domain structural modeling is studied. Both constitutive and structural aspects are investigated. LÄS MER