Sökning: "wavelet"

Visar resultat 1 - 5 av 104 avhandlingar innehållade ordet wavelet.

  1. 1. Wavelet Galerkin methods for elastic multibody systems with unilateral contact constraints

    Författare :José Díaz López; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computer science; Elastic MBS; Contact; Unilateral Contraints; Wavelet; DAE; Daubechies; numerical analysis; systems; control; Datalogi; numerisk analys; system; kontroll;

    Sammanfattning : In this thesis we investigate the applicability of wavelets to simulate the time behavior of elastic multibody systems (MBS) with contact constraints. For this end, a wavelet element method (WEM) was implemented, exploiting the special structure of the coupled ODE/PDE equations that govern elastic MBS. LÄS MER

  3. 2. Wavelet Analysis of Economic Time Series

    Författare :Fredrik N G Andersson; Nationalekonomiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; freight transportation activity; wavelet analysis; cointegration; inflation; bandspectrum regression; money; coreinflation;

    Sammanfattning : Economic theory commonly distinguishes between different time horizons such as the short run and the long run. Models with many time horizons are easily studied in the frequency domain, because the various time horizons are associated with a particular frequency or band of frequencies. LÄS MER

  4. 3. 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

  5. 4. Noise diagnostics of Stationary and Non-Stationary Reactor Processes

    Författare :Carl Sunde; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; core-barrel vibrations; break-frequency method; wavelet; decay ratio; detector tube impacting; two-phase flow; spectral analysis; noise diagnostics;

    Sammanfattning : This thesis concerns the application of noise diagnostics on different problems in the area of reactor physics involving both stationary and non-stationary core processes. Five different problems are treated, divided into three different parts. LÄS MER

  7. 5. Hydrodynamics of plane liquid jets aimed at applications in paper manufacturing

    Författare :Daniel Söderberg; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; liquid jet; transition; break-up; stability; wavelet; free surface; waves; streamwise streaks; fibre suspension; headbox; forming; shadowgraph; hot-film; Engineering mechanics; Teknisk mekanik;

    Sammanfattning : Process industries are in general depending, in one way or the other, on fluid mechanics.Specifically, paper manufacturing, which probably is the dominant processindustry in Sweden, is depending on the flow of cellulose fibres suspended in water. LÄS MER