Sökning: "periodic signals"

Visar resultat 11 - 15 av 32 avhandlingar innehållade orden periodic signals.

  1. 11. Cyclic AMP Oscillations in Insulin-Secreting Cells

    Författare :Jenny Sågetorp; Anders Tengholm; Erik Gylfe; Lena Stenson; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Medical cell biology; Medicinsk cellbiologi;

    Sammanfattning : Cyclic AMP is an intracellular messenger that regulates numerous processes in various types of cells. In pancreatic β-cells, cAMP potentiates the secretion of insulin by promoting Ca2+ signals and by amplifying Ca2+-triggered exocytosis. Whereas Ca2+ signals have been extensively characterized, little is known about the kinetics of cAMP signals. LÄS MER

  3. 12. Intermodulation Distortion in Active and Passive Components

    Författare :Martin Mattsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Intermodulation distortion; hyperabrupt junction; polynomial model; passive intermodulation; nonlinear analysis; loaded-line phase shifter; varactor modeling;

    Sammanfattning : Wireless communication is growing rapidly, and the demand for higher data rate, low latency, and availability leads to a more complex infrastructure with new challenges. Multiple communication systems have to co-exist in a densely populated frequency-spectrum, where higher power levels and more sensitive receivers are required. LÄS MER

  4. 13. Stealth radomes

    Författare :Sören Poulsen; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic scattering; Dichroic structures; Frequency selective surface; Elektroteknik; FSS; Electrical engineering; Radomes;

    Sammanfattning : This dissertation deals with periodic structures that are used as free-space electromagnetic filters. Two types of periodic structures are treated, namely the so called frequency selective surface (FSS) and the artificial puck plate (APP) structure. LÄS MER

  5. 14. Predictable cyclic computations in autonomous systems : a computational model and implementation

    Författare :Magnus Morin; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Cyclic computations under real-time constraints naturally occur in systems which use periodic sampling to approximate continuous signals for processing in a computer. In complex control systems, often with a high degree of autonomy, there is a need to combine this type of processing with symbolic computations for supervision and coordination. LÄS MER

  7. 15. Channel Estimation and Prediction for MIMO OFDM Systems : Key Design and Performance Aspects of Kalman-based Algorithms

    Författare :Daniel Aronsson; Mikael Sternad; Ove Edfors; Uppsala universitet; []
    Nyckelord :channel estimation; channel prediction; OFDM; Kalman filtering; Electrical Engineering with specialization in Signal Processing; Elektroteknik med inriktning mot signalbehandling;

    Sammanfattning : Wireless broadband systems based on Orthogonal Frequency Division Multiplexing (OFDM) are being introduced to meet demands for high data transfer rates. In multiple users systems, the available bandwidth has to be shared efficiently by several users. The radio channel quality will fluctuate, or fade, as users move. LÄS MER