Sökning: "Efficiency"

Visar resultat 21 - 25 av 5936 avhandlingar innehållade ordet Efficiency.

  1. 21. Linearization of High Efficiency Transmitters for Wireless Communications

    Författare :Haiying Cao; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dynamic load modulation; Behavioral model; digital predistortion; I Q imbalance; Volterra series; efficiency; power amplifier; transmitter;

    Sammanfattning : In recent years, reducing energy consumption in wirelesscommunication systems has gained prominence. In order to achieve this energy saving, high power efficiency is necessary for the wireless transmitters used. LÄS MER

  3. 22. High-efficiency Power Amplification Techniques for Wireless Transmitters

    Författare :Hossein Mashad Nemati; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; load modulation; LDMOS; supply modulation; GaN HEMT; Power amplifier; wireless communications.; GaAs mHEMT; efficiency;

    Sammanfattning : The low efficiency of existing power amplifiers (PAs) is causing excessive energy consumption in wireless systems. Improving the PA efficiency is therefore of great environmental and economical importance. LÄS MER

  4. 23. Running-in of gears - surface and efficiency transformation

    Författare :Mario Sosa; Ulf Olofsson; Stefan Björklund; Ulf Sellgren; Jorge Seabra; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; running-in; surface transformation; efficiency; gears; ground; superfinished; Machine Design; Maskinkonstruktion;

    Sammanfattning : With ever shorter development times and market demands on overall system performance such as efficiency, reliability and low maintenance, accurate predictive tools are necessary and gear drives prove to be no exception. All these characteristics have an impact on a process which has remained a riddle: running-in. LÄS MER

  5. 24. Efficiency of the trackwork scheduling process in Sweden

    Författare :Daria Ivina; Trafik och väg; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Railways; Maintenance management; Trackwork scheduling; Project Uncertainties; Lean; Efficiency;

    Sammanfattning : Efficient scheduling is vital for railway maintenance, which is increasingly challenged by rising train traffic and infrastructure wear. Trackwork often necessitates the reduction of train speeds and the partial or complete closure of tracks. LÄS MER

  7. 25. An experimental investigation of spur gear efficiency and temperature : A comparison between ground and superfinished surfaces

    Författare :Martin Andersson; Ulf Olofsson; Bengt-Göran Rosén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; gears; ground; superfinished; efficiency; temperature; running-in; dip lubrication; spray lubrication; Machine Design; Maskinkonstruktion;

    Sammanfattning : This thesis focuses on reliability when testing gear efficiency and on how gear mesh efficiency can be increased without detrimental effects on the gears. Test equipment commonly used in gear research was analysed to identify important parameters for gear efficiency testing. LÄS MER