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Visar resultat 1 - 5 av 299 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Prediction of Mobile Radio Channels : Modeling and Design

    Författare :Torbjörn Ekman; Rodney Vaughan; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Systemteknik; mobile radio channel; fading; channel model; channel estimation; channel prediction; power prediction; Systemteknik; Systems engineering; Systemteknik; Signal Processing; signalbehandling;

    Sammanfattning : Prediction of the rapidly fading envelope of a mobile radio channel enables a number of capacity improving techniques like fast resource allocation and fast link adaptation. This thesis deals with linear prediction of the complex impulse response of a channel and unbiased quadratic prediction of the power. LÄS MER

  3. 2. Modeling of Wind Turbines for Power System Studies

    Författare :Tomas Petru; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flicker; fault response; power quality; wind turbine; power system stability; measurements; prediction; verification; grid simulation; modeling;

    Sammanfattning : The power quality impact of wind turbines on the electric grid and the response of the wind turbines to faults in the electric grid are investigated in this thesis. A detailed model of a stall-regulated, fixed-speed wind turbine system capable of predicting the flicker impact on the connected grid is presented and compared with field measurements. LÄS MER

  4. 3. Modeling of wind turbines for power system studies

    Författare :Tomas Petru; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; power quality; wind turbine; measurements; verification; flicker; modeling; prediction;

    Sammanfattning : .... LÄS MER

  5. 4. Grease lubrication mechanisms in bearing seals

    Författare :Pieter Baart; Richard F. Salant; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

    Sammanfattning : Rolling bearings contain seals to keep lubricant inside and contaminants outside the bearing system. These systems are often lubricated with grease; the grease acts as a lubricant for the bearing and seal and improves the sealing efficiency. In this thesis, the influence of lubricating grease on bearing seal performance is studied. LÄS MER

  7. 5. Wind Power and Natural Disasters

    Författare :Jon Olauson; Mikael Bergkvist; Stefan Ivanell; Uppsala universitet; []
    Nyckelord :Wind power; Natural disasters; Hybrid energy system; Meteorological model; Statistical model; Variability; Wind power integration;

    Sammanfattning : Wind power can be related to natural disasters in several ways. This licentiate thesis gives some background and introduces four papers devoted to two aspects of this relation. The first section looks into how small-scale wind energy converters (WECs) could be used to generate power after a natural disaster. LÄS MER