Sökning: "periodogram"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet periodogram.

  1. 1. Testing for Periodicity and Trend in Long-Memory Processes

    Författare :Abdullah Almasri; Statistiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; temperature data.; sunspots data; wind speed data; varve data; Siegel’s test; Fisher’s test; periodogram; Fractional difference process; Discrete wavelet transform; operations research; programming; actuarial mathematics; Statistik; operationsanalys; programmering; aktuariematematik; Wavelets; Statistik;

    Sammanfattning : This thesis presents methods of testing the periodicity and trend for the time series, which exhibit dependence over long periods of time. Many such processes can be modeled by a class of models called fractionally differenced processes. LÄS MER

  3. 2. Frequency Tracking for Speed Estimation

    Författare :Martin Lindfors; Rickard Karlsson; Gustaf Hendeby; Fredrik Gustafsson; Tomas McKelvey; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Estimating the frequency of a periodic signal, or tracking the time-varying frequency of an almost periodic signal, is an important problem that is well studied in literature. This thesis focuses on two subproblems where contributions can be made to the existing theory: frequency tracking methods and measurements containing outliers. LÄS MER

  4. 3. 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

  5. 4. Discrete Stochastic Time-Frequency Analysis and Cepstrum Estimation

    Författare :Johan Sandberg; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ambiguity domain; time-frequency analysis; time-frequency representations; covariance function; non-stationary random processes; Speaker recognition; MFCC; cepstrum;

    Sammanfattning : The theory of stochastic time-frequency analysis of non-stationary random processes has mostly been developed for processes in continuous time. In practice however, random processes are observed, processed, and interpreted at a finite set of time points. LÄS MER

  7. 5. Signal processing approaches on otoacoustic emissions

    Författare :Jun Cheng; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :otoacoustic emissions; signal processing; time-frequency representation; cochlea; outer hair cell; neonatal hearing screening; basilar membrane nonlinearity; bounce phenomenon; spectral estimation; interrelations of OAEs;

    Sammanfattning : The recent achievement on the measurement of otoacoustic emissions (OAEs) is based on a novel technical development of digital signal processing. OAEs measured in the external ear canal are normal by-products of the active process in hearing, which was discovered by Kemp (1978). LÄS MER