Sökning: "adaptive optics"

Visar resultat 21 - 25 av 25 avhandlingar innehållade orden adaptive optics.

  1. 21. Myopia control and peripheral vision

    Författare :Petros Papadogiannis; Linda Lundström; Peter Unsbo; Nicola Logan; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; myopia; peripheral vision; psychophysics;

    Sammanfattning : The rapid rise in myopia prevalence has caused an urgent need for effectivemyopia control interventions. This thesis investigates the role of theperipheral optics of the human eye in myopia progression. It was initiallybelieved that the axial elongation of the myopic eye is caused only by thedefocus signals presented to the central retina. LÄS MER

  3. 22. Novel beam shaping and computer vision methods for laser beam welding

    Författare :Yongcui Mi; Antonio Ancona; Fredrik Sikström; Isabelle Choquet; Högskolan Väst; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser beam welding; Beam shaping; Deformable mirror; Process monitoring; Process control; Model validation; Computer vision; Machine learning; Butt joint; T-joint.; Lasersvetsning; Beam shaping; Deformerbar spegel; Processövervakning; Processkontroll; Modellvalidering; Datorsyn; Maskininlärning; Butt joint; T-fogar;

    Sammanfattning : Laser beam welding has been widely applied in different industrial sectors due to its unique advantages. However, there are still challenges, such as beam positioning in T-joint welding, and gap bridging in butt joint welding,especially in the case of varying gap width along a joint. LÄS MER

  4. 23. Production of high quality 11C beams for radiation treatment and accurate PET-CT dose delivery verification

    Författare :Marta Lazzeroni; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Radiation therapy with external beams of positron emitter light ions offers the optimal solution for simultaneously treating and in vivo monitoring the delivery of the dose in 3D with Positron Emission Tomography (PET) or PET-Computed Tomography (CT) imaging. Specifically, positron emitter light ion beams merge the main distinctive advantages of light ion therapy, namely a high conformal and biological effective dose delivery to the tumor, an optimal penumbra, and sparing of the surrounding normal tissues, with the advantage of a high β+-activity signal mainly produced directly by the beam itself, and therefore not primarily dependent on the specific stoichiometry of the body tissues. LÄS MER

  5. 24. Quasar host galaxies at intermediate and high redshifts

    Författare :Eva Örndahl; Bengt Gustafsson; Jari Kotilainen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Active galaxies; Quasars; Host galaxies; Imaging; Photometry; Magnitudes; Colours; Morphology; Statistical methods; High-redshift; Infrared; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Sammanfattning : Quasars form one of the most energetic phenomena in the universe, and can be traced out to very large redshifts. By studying the galaxies which host the active nuclei, important insights can be gained into the processes that trigger and maintain the quasar powerhouse. LÄS MER

  7. 25. Characterising Emblematic Binaries at the Lowest Stellar and Substellar Masses

    Författare :Per Calissendorff; Markus Janson; Koraljka Mužić; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; astrometry; binaries; brown dwarfs; low-mass stars; multiplicity; substellar; Astronomy; astronomi;

    Sammanfattning : Stars are involved in most research fields of astronomy, ranging from studies of faraway galaxies, exploding supernovae, to more nearby exoplanets and even our own Sun. As such, it is paramount that our physical interpretation of stars is accurate. LÄS MER