Sökning: "Smooth transition"

Visar resultat 21 - 25 av 94 avhandlingar innehållade orden Smooth transition.

  1. 21. Superfluid Phase Transitions in Disordered Systems

    Författare :Hannes Meier; Mats Wallin Wallin; Peter Olsson; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis presents results from large scale Monte Carlo simulations of systems subject to a superfluid phase transition in the presence of disorder. The simulations are performed by state-of-the-art, collective Monte Carlo algorithms treating phase degrees of freedom in effective models with amplitude fluctuations integrated out. LÄS MER

  3. 22. Testing for Unit Root against LISTAR Model : Wavelet Improvement under GARCH Distortion

    Författare :Yushu Li; Ghazi Shukur; Växjö universitet; []
    Nyckelord :;

    Sammanfattning : In this paper we propose a Nonlinear Dickey-Fuller F test for unit root against first order Logistic Smooth Transition Autoregressive LISTAR (1) model with time as the transition variable. The Nonlinear Dickey-Fuller F test statistics is established under the null hypothesis of random walk without drift and the alternative model is a nonlinear LSTAR (1) model. LÄS MER

  4. 23. Roughening in dimer models : Random matrix statistics and surface fluctuations

    Författare :Scott Mason; Kurt Johansson; Alexey Bufetov; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Matematik; Mathematics;

    Sammanfattning : The field of mathematical statistical mechanics sits at the intersection of probability theory and mathematical physics. It consists of the rigorous analysis of models in statistical mechanics, such as dimer and lattice models - of which the Ising model is a classical example. LÄS MER

  5. 24. Development of Numerical Methods for Turbulent Flow in Complex Rotating Systems

    Författare :Peter Hedberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; fluid mechanics; computer code; rotating geometries; turbomachinery;

    Sammanfattning : A computer code has been developed to predict three-dimensional incompressible turbulent flow in complex rotating geometries. The application in mind is turbomachinery in general. However such a code is able to treat a large number of problems in fluid mechanics. LÄS MER

  7. 25. Ionization of large molecules with short laser pulses

    Författare :Mikael Kjellberg; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysik; Photoelectron spectroscopy; Momentum mapping imaging; thermal ionization; above threshold ionization; molecular fusion; fullerenes; polyaromatic hydrocarbons; femtosecond-laser.;

    Sammanfattning : The decay dynamics of fullerenes and polyaromatic hydrocarbons (PAH) after femtosecond-laser excitation have been studied experimentally by electron momentum mapping and mass spectrometry. The electron spectra of fullerenes and large PAH-molecules were found to be exponentially decreasing with energy without any distinct peaks outside the photon energy. LÄS MER