Sökning: "short time Fourier transform"

Visar resultat 11 - 15 av 19 avhandlingar innehållade orden short time Fourier transform.

1. 11. 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

3. 12. Algorithms for Molecular Dynamics Simulations

   Författare :Fredrik Hedman; Aatto Laaksonen; Tom Darden; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; molecular dynamics; MD; first principles molecular dynamics; quantum mechanics; liquid water; parallel algorithm; data parallel; MPI; Coulombic interaction; Ewald summation; nonuniform fast Fourier transform; FFT; FFTW; NFFT; ENUF; Physical chemistry; Fysikalisk kemi;

   Sammanfattning : Methods for performing large-scale parallel Molecular Dynamics(MD) simulations are investigated. A perspective on the field of parallel MD simulations is given. Hardware and software aspects are characterized and the interplay between the two is briefly discussed. LÄS MER

4. 13. Optimisation and Validation of Dynamic Susceptibility Contrast MRI Perfusion Measurements

   Författare :Linda Knutsson; Lund Medicinsk strålningsfysik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Nukleärmedicin; radiobiologi; Nuclear medicine; radiobiology; radiologi; tomografi; medicinsk instrumentering; tomography; medical instrumentation; Clinical physics; cerebral blood volume; mean transit time; cerebral blood flow; perfusion; dynamic susceptibility contrast MRI arterial input function; Klinisk fysiologi; radiology;

   Sammanfattning : The studies presented in this thesis concern the optimisation and evaluation of the dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) technique for the assessment of perfusion-related parameters of the brain, such as cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT). Several methodological factors influence these measurements, for example, contrast-agent administration, arterial input function (AIF) registration, choice of deconvolution algorithm and the choice of pulse-sequence parameters. LÄS MER

5. 14. Drill Failure Detection based on Sound using Artificial Intelligence

   Författare :Thanh Tran; Jan Thim; Sebastian Bader; Kalle Åström; Mittuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Convolutional neural network; machine failure detection; Mel-spectrogram; long short-term memory; sound signal processing;

   Sammanfattning : In industry, it is crucial to be able to detect damage or abnormal behavior in machines. A machine's downtime can be minimized by detecting and repairing faulty components of the machine as early as possible. It is, however, economically inefficient and labor-intensive to detect machine fault sounds manual. LÄS MER

7. 15. Auri sacra fames : Interest Rates -- Prediction, Jumps and the Market Price of Risk

   Författare :Carl Wilkens; Mats Persson; Peter Sellin; Michael Bergman; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; instantaneous interest rate; fixed income market; asset pricing; derivative pricing; Economics; Nationalekonomi;

   Sammanfattning : This thesis consists of three essays investigating different aspects of interest rates."Prediction of Future Risk-Neutral Short-Term Interest Rate Densities: Can the Black, Derman and Toy Model Assist?" (Co-authored with David Vestin. LÄS MER