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Visar resultat 1 - 5 av 66 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Modelling and Quality Assessment of Atrial Fibrillatory Waves

   Författare :Mikael Henriksson; Avdelningen för Biomedicinsk teknik; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ECG; signal processing; atrial fibrillation; signal quality; catheter ablation; atrial fibrillatory waves; f-waves;

   Sammanfattning : This doctoral thesis revolves around the analysis of electrocardiogram (ECG) signals during atrial fibrillation (AF). Special emphasis is put on the atrial fibrillatory waves, sometimes called the f-waves, which is the ECG component reflecting the electrical activity of the atria. LÄS MER

3. 2. Nonlinear Interaction Between Ultrasonic Waves and Cracks and Interfaces

   Författare :Milan Poznic; Leif Kari; Bruce Drinkwater; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ultrasonic waves; crack; modulation; rough interface; partially closed; surface-breaking; fluid-filled; Acoustics; Akustik;

   Sammanfattning : The subject of this thesis is the development of new ultrasound inspection techniques for detection of cracks that are smaller than the wavelength of the inspecting wave and the characterization of cracks in fluid-filled pipes as either surface-breaking or subsurface. The spectrum of the scattered field of a partially closed crack comprises harmonic components not expected to be found in the case of linear scatterers such as pores or inclusions. LÄS MER

4. 3. Determining and Optimizing the Current and Magnetic Field Dependence of Spin-Torque and Spin Hall Nano-Oscillators : Toward Next-Generation Nanoelectronic Devices and Systems

   Författare :Seyed Amir Hossein Banuazizi; Johan Åkerman; Erik Wahlström; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; nanoelectronics; spintronics; nanomagnetism; ferromagnetic materials; microwave oscillators; magnetization dynamics; spin waves; giant magneto-resistance; spin Hall effect; spin-torque nano-oscillators; spin Hall nano-oscillators; numerical modeling; electrical characterization; microwave characterization; magnetic force microscopy.; Fysik; Physics; Teknisk materialvetenskap; Materials Science and Engineering; Informations- och kommunikationsteknik; Information and Communication Technology; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Spin-torque and spin Hall nano-oscillators are nanoscale devices (about 100 nm) capable of producing tunable broadband high-frequency microwave signals ranging from 0.1 GHz to over 65 GHz that several research groups trying to reach up to 200 - 300 GHz. LÄS MER

5. 4. Loads and responses for planing craft in waves

   Författare :Anders Rosén; Dan Zenker; Brian Hayman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Applied mechanics; planing craft; high-speed craft; waves; model tests; sull-scale trials; Teknisk mekanik; Engineering mechanics; Teknisk mekanik;

   Sammanfattning : Experimental and numerical analysis of loads and responses for planing craft in waves is considered. Extensive experiments have been performed on a planing craft, in full-scale as well as in model scale. The test set-ups and significant results are reviewed. LÄS MER

7. 5. Optimization and Physical Bounds for Passive and Non-passive Systems

   Författare :Yevhen Ivanenko; Sven Nordebo; Börje Nilsson; Mats Gustafsson; Mariana Dalarsson; Aaron Welters; Linnéuniversitetet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Convex optimization; physical bounds; Herglotz functions; quasi-Herglotz functions; passive systems; non-passive systems; approximation; absorption in lossy media; Waves; Signals and Systems; Vågor; signaler och system;

   Sammanfattning : Physical bounds in electromagnetic field theory have been of interest for more than a decade. Considering electromagnetic structures from the system theory perspective, as systems satisfying linearity, time-invariance, causality and passivity, it is possible to characterize their transfer functions via Herglotz functions. LÄS MER