Sökning: "Attenuation"

Visar resultat 1 - 5 av 325 avhandlingar innehållade ordet Attenuation.

  1. 1. Structural sound transmission and attenuation in lightweight structures

    Detta är en avhandling från Chalmers University of Technology

    Författare :Lars-Göran Sjökvist; RISE.; Chalmers tekniska högskola.; Chalmers University of Technology.; [2008]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Akustik; Acoustics; acoustics; attenuation; flanking transmission; Fourier transform; junction; lightweight building; sound insulation; stiffened plate; stiffeners; wooden houses;

    Sammanfattning : Everyone wants a peaceful and quiet home, but in noisy cities it is a challenge to create such homes. New building techniques are mostly introduced for other purposes than noise control -- stability, economy, heat transfer and so on. LÄS MER

  2. 2. Evaluation of attenuation and scatter corrections in lung and brain SPECT

    Detta är en avhandling från Göteborg : Göteborgs universitet

    Författare :Agnetha Gustafsson; [2001]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; SPECT; attenuation; scatter; detectability; Monte Carlo simulation; MEDICINE; MEDICIN;

    Sammanfattning : Single Photon Emission Computed Tomography (SPECT) is used to image functional processes in the human body. The image process is affected by physical effects such as attenuation, scatter, spatial resolution and statistical noise. LÄS MER

  3. 3. Acoustical properties of earplugs

    Detta är en avhandling från Engineering Acoustics, LTH, Lund University

    Författare :Per Hiselius; Lunds universitet.; Lund University.; [2005]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinteknik; hydraulik; vakuumteknik; vibrationer; akustik; vibration and acoustic engineering; vacuum technology; hydraulics; Mechanical engineering; acoustic modelling; objective measurement; insertion loss; earplugs; HPE; HPD; hearing protectors; Two-Port; Four-Pole; attenuation; electro acoustics; acoustics;

    Sammanfattning : Popular Abstract in Swedish En ny mätuppställning har utvecklats och tillämpats på öronproppar (hörselproppar). Mätuppställning gör det möjligt att skatta de akustiska egenskaperna i form av en så kallad tvåport. LÄS MER

  4. 4. Colour Correction of Underwater Images Using Spectral Data

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Julia Åhlén; Högskolan i Gävle.; Uppsala universitet.; [2005]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TECHNOLOGY Information technology Computer science; TEKNIKVETENSKAP Informationsteknik Datavetenskap; Colour; Correction; Attenuation; Coefficient; Underwater; TECHNOLOGY Information technology Image analysis; TEKNIKVETENSKAP Informationsteknik Bildanalys; Bildanalys; Bildanalys;

    Sammanfattning : For marine sciences sometimes there is a need to perform underwater photography. Optical properties of light cause severe quality problems for underwater photography. Light of different energies is absorbed at highly different rates under water causing significant bluishness of the images. LÄS MER

  5. 5. Novel computational methods for image analysis and quantification using position sensitive radiation detectors

    Detta är en avhandling från Stockholm : Medicinsk strålningsfysik (tills m KI)

    Författare :Alejandro Sanchez Crespo; Stockholms universitet.; [2005]
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; SPET; PET; CMOS; spatial resolution; photon depth of interaction; positron annihilation; positron range; non-collinearity; scatter; attenuation; lung ventilation; lung perfusion; breast tumour; VETERINARY MEDICINE Medicine; VETERINÄRMEDICIN Medicin;

    Sammanfattning : The major advantage of position sensitive radiation detector systems lies in their ability to non invasively map the regional distribution of the emitted radiation in real-time. Three of such detector systems were studied in this thesis, gamma-cameras, positron cameras and CMOS image sensors. LÄS MER