Sökning: "Wavelet transforms"
Hittade 5 avhandlingar innehållade orden Wavelet transforms.
1. Wavelet Analysis of Economic Time Series
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
2. Wavelet theory and some of its applications
Sammanfattning : This thesis deals with applied mathematics with wavelets as a joint subject. There is an introduction and two extensive papers, of which one is already published in an international journal. LÄS MER
3. Hilbert space frames and bases : a comparison of Gabor and wavelet frames and applications to multicarrier digital communications
Sammanfattning : Several signal processing applications today are based on the use of different transforms. The signals under consideration are written as a linear combination (or series) of some predefined set of functions. Traditionally, orthogonal bases have been used for this purpose, for example, in the discrete Fourier transform. LÄS MER
4. Feature Extraction for Low-Frequency Signal Classification
Sammanfattning : The development of the International Monitoring System (IMS) for the verification of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has led to a rapid revival of interest in infrasound. Furthermore, the installation of low-frequency sensors at seismic sites has increased in recent years, providing researchers with large and heterogeneous data-sets in near real-time. LÄS MER
5. Features and Origin of Electromagnetic Fields Generated by Lightning Flashes
Sammanfattning : Negative cloud-to-ground (CG) lightning flashes transport negative charge from cloud to ground. Negative ground flashes typically involve various processes identified as preliminary breakdown, stepped leader, return stroke, dart leader, dart-stepped leader, subsequent return stroke, and cloud activity between strokes, such as regular pulse trains and chaotic pulse trains. LÄS MER