Sökning: "Wavelet Transform"

Visar resultat 16 - 20 av 26 avhandlingar innehållade orden Wavelet Transform.

1. 16. Multiscale analysis of multi-channel signals

   Författare :Håkan Carlqvist; Jan-Olov Strömberg; Maria Hansson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematical statistics; Matematisk statistik; Mathematical statistics; Matematisk statistik;

   Sammanfattning : I: Amplitude and phase relationship between alpha and beta oscillations in the human EEG We have studied the relation between two oscillatory patterns within EEG signals (oscillations with main frequency 10 Hz and 20 Hz), with wavelet-based methods. For better comparison, a variant of the continuous wavelet transform, was derived. LÄS MER

3. 17. Feature Extraction for Low-Frequency Signal Classification

   Författare :José Chilo; Thomas Lindblad; Christian Bohm; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; infrasound; seismic signals; feature extraction; wavelets; fingerprints; mining; multimodal data space; Atomic physics; Atomfysik; Electronics;

   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

4. 18. Improving detection and diagnosis of bearing failures in wind turbine drivetrains

   Författare :Daniel Strömbergsson; Pär Marklund; Kim Berglund; Ulf Olofsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machine Elements; Maskinelement;

   Sammanfattning : Wind power has in the last 20 years grown into one of the main sources of renewable energy in the world, with both the amount and size of the turbines increasing substantially. One of the major challenges for the wind power industry is the premature failures of especially the drivetrain components. LÄS MER

5. 19. Spectrum Sensing for Dynamic Spectrum Access in Cognitive Radio

   Författare :Inna Valieva; Dag Stranneby; Mälardalens universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Abstract. The number of mobile devices is constantly growing, and the exclusivestatic spectrum allocation approach is leading to the spectrum scarcity problem whensome of the licensed bands are heavily occupied and others are nearly unused.Spectrum sharing and opportunistic spectrum access allow achieving more efficientspectrum utilization. LÄS MER

7. 20. The nature of kinematic structures in the Galactic disc

   Författare :Iryna Kushniruk; Astronomi - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy : evolution; Galaxy: structure; Galaxy : kinematics and dynamics;

   Sammanfattning : The velocity distribution of stars in the Galactic disc is complex and consists of a vast number of kinematic structures, that is, stars that share similar velocity components. The reasons why some stars move together may be different and are related to dynamical processes connected to the Galaxy, both internal as well as external ones, such as resonances with the Galactic bar or the Galactic spiral arm structure, dissolution of open clusters, or merger events with other galaxies. LÄS MER