Sökning: "Rickard Persson"

Visar resultat 6 - 8 av 8 avhandlingar innehållade orden Rickard Persson.

  1. 6. Science mapping and research evaluation : a novel methodology for creating normalized citation indicators and estimating their stability

    Författare :Cristian Colliander; Rickard Danell; Olle Persson; Jesper Schneider; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; document-document similarity; science mapping; citation analysis; citation normalization; stability analysis; citation impact; research evaluation; library and information science; biblioteks- och informationsvetenskap;

    Sammanfattning : The purpose of this thesis is to contribute to the methodology at the intersection of relational and evaluative bibliometrics. Experimental investigations are presented that address the question of how we can most successfully produce estimates of the subject similarity between documents. LÄS MER

  3. 7. On Active Secondary Suspension in Rail Vehicles to Improve Ride Comfort

    Författare :Anneli Orvnäs; Sebastian Stichel; Rickard Persson; Roger Goodall; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rail vehicle; active secondary suspension; ride comfort; sky-hook damping; H∞ control; multi-body simulations; on-track tests; Järnvägsgruppen - Gröna tåget; Järnvägsgruppen - Gröna tåget; Järnvägsgruppen - Fordonsteknik; Järnvägsgruppen - Fordonsteknik;

    Sammanfattning : One way to make rail vehicles a competitive means of transportation is to increase running speed. However, higher speeds usually generate increased forces and accelerations on the vehicle, which have a negative effect on ride comfort. With conventional passive suspension, it may be difficult to maintain acceptable passenger comfort. LÄS MER

  4. 8. On Active Suspension in Rail Vehicles

    Författare :Alireza Qazizadeh; Sebastian Stichel; Rickard Persson; T. X. Mei; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active suspension; ride comfort; wear; skyhook control; H_infinity control; two-axle rail vehicle; safety; Farkostteknik; Vehicle and Maritime Engineering;

    Sammanfattning : The topic of this PhD thesis is active suspension in rail vehicles whichis usually realized through sensors, controllers and actuation components.A well established example of an active suspension is the tiltingcontrol system used to tilt the carbody in curves to reduce centrifugalacceleration felt by passengers. LÄS MER