Sökning: "spectral analysis"

Visar resultat 6 - 10 av 511 avhandlingar innehållade orden spectral analysis.

  1. 6. Spectral analysis of the heart rate variability : a methodological study

    Författare :Urban Niklasson; Umeå universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Heart-rate variability; R-R interval; cardiac autonomic function; spectral analysis; IPFM model;

    Sammanfattning : Heart rate and other cardiovascular variables are not steady but fluctuate over time. The evolution of computer technology the last 2 decades has made detailed analysis of the fluctuations possible and has focused the attention to the information content of the variability. LÄS MER

  3. 7. Spectral Asymptotics in Porous Media

    Författare :Hermann Douanla Yonta; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Homogenization; reiterated homogenization; perforated domains; multiscale perforation; eigenvalue problems; ergodic algebra; algebra with mean value; Gelfand transformation; two-scale convergence; Sigma-convergence; Gelfand transformation;

    Sammanfattning : .... LÄS MER

  4. 8. Computational Aspects of Maass Waveforms

    Författare :Fredrik Strömberg; Dennis A. Hejhal; Andreas Strömbergsson; David Farmer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical analysis; Maass waveform; Congruence subgroup; Noncongruence subgroup; Multiplier system; Theta multiplier system; Eta multiplier system; real weight; Hecke operator; Involution; Dirichlet character; Spectral Theory; Computation; Matematisk analys; Mathematical analysis; Analys; matematik; Mathematics;

    Sammanfattning : The topic of this thesis is computation of Mass waveforms, and we consider a number of different cases: Congruence subgroups of the modular group and Dirichlet characters (chapter 1); congruence subgroups and general multiplier systems and real weight (chapter 2); and noncongruence subgroups (chapter 3). In each case we first discuss the necessary theoretical background. LÄS MER

  5. 9. The spectral reflectance of coniferous tree stands and of barley influenced by stress : an analysis of field measured spectral data

    Författare :Johan Kleman; Stockholms universitet; []
    Nyckelord :spectral reflectance; field measurement; middle infrared; crops; fertilisation; irrigation; coniferous forest; helicopter; measuring geometry;

    Sammanfattning : This thesis focuses on the spectral signatures for vegetation. Knowledge about the spectral characteristics of different vegetation types is imperative for an efficient use of existing remote sensing systems, and also to provide guidelines for sensor development. LÄS MER

  7. 10. Spectral analysis and magnetic resonance spectroscopy

    Författare :Tomas Sundin; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Nonparametric spectral analysis; magnetic resonance spectroscopy; parameter estimation; maximum likelihood estimation; nonlinear least squares; Signal processing; Signalbehandling; Signal Processing; Signalbehandling;

    Sammanfattning : This dissertation is concerned with nonparametric approaches for spectral analysis (SA) and algorithms for magnetic resonance spectroscopy (MRS) data analysis.A method to obtain the optimal smoothing window for the class of SA methods based on local smoothing of the periodogram is proposed. LÄS MER