Sökning: "periodic signals"

Visar resultat 21 - 25 av 32 avhandlingar innehållade orden periodic signals.

  1. 21. On one-dimensional dynamical systems and commuting elements in non-commutative algebras

    Författare :Alex Behakanira Tumwesigye; Sergei Silvestrov; Johan Richter; Linus Carlsson; Viktor Abramov; Mälardalens högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Commutativity; dynamical systems; commutant; Mathematics Applied Mathematics; matematik tillämpad matematik;

    Sammanfattning : This thesis work is about commutativity which is a very important topic in mathematics, physics, engineering and many other fields. Two processes are said to be commutative if the order of "operation" of these processes does not matter. LÄS MER

  3. 22. Analysis and control of transitional shear flows using global modes

    Författare :Shervin Bagheri; Dan Henningson; Alessandro Bottaro; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; flow control; hydrodynamic stability; global modes; jet in crossflow; flat-plate boundary layer; laminar-turbulent transition; Arnoldi method; Koopman modes; balanced truncation; direct numerical simulations.; Fluid mechanics; Strömningsmekanik;

    Sammanfattning : In this thesis direct numerical simulations are used to investigate two phenomenain shear flows: laminar-turbulent transition over a flat plate and periodicvortex shedding induced by a jet in cross flow. The emphasis is on understanding and controlling the flow dynamics using tools from dynamical systems and control theory. LÄS MER

  4. 23. Event Based Sampling with Application to Spectral Estimation

    Författare :Niclas Persson; Fredrik Gustafsson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Event based sampling; Time based sampling; Tire pressure monitoring system;

    Sammanfattning : In this thesis event based sampling, estimation of a single resonance frequency and the application indirect tire pressure monitoring system are studied.Event based sampling is an alternative to traditional uniform or equidistant sampling. In event based sampled systems, signals are sampled only when certain pre-defined events take place. LÄS MER

  5. 24. On Spectrum Sensing for Secondary Operation in Licensed Spectrum : Blind Sensing, Sensing Optimization and Traffic Modeling

    Författare :Mohamed Hamid; Ben Slimane Slimane; Niclas Björsell; Octavia Dobre; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Cognitive Radio; Spectrum Sensing; Sensing Optimization; Blind Sensing; Traffic Modelling; Energy detection; Maximumum-minimum Eigenvalue Detection; Discriminant anlysis; Informations- och kommunikationsteknik; Information and Communication Technology;

    Sammanfattning : There has been a recent explosive growth in mobile data consumption. This, in turn, imposes many challenges for mobile services providers and regulators in many aspects. One of these primary challenges is maintaining the radio spectrum to handle the current and upcoming expansion in mobile data traffic. LÄS MER

  7. 25. EFFICIENCY OF FLEXIBLE FIXTURES: DESIGN AND CONTROL

    Författare :Ilker Erdem; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; control; design; fixture; assembly; manufacturing; efficiency; flexible; production;

    Sammanfattning : The manufacturing industries have been using flexible production technologies to meet the demand for customisation. As a part of production, fixtures have remained limited to dedicated technologies, even though numerous flexible fixtures have been studied and proposed by both academia and industry. LÄS MER