Sökning: "attenuation"

Visar resultat 1 - 5 av 408 avhandlingar innehållade ordet attenuation.

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

   Författare :Lars-Göran Sjökvist; RISE; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sound insulation; acoustics; wooden houses; Fourier transform; lightweight building; stiffened plate; junction; stiffeners; flanking transmission; attenuation;

   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

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

   Författare :Agnetha Gustafsson; Bertil Axelsson; Göteborgs universitet Avdelningen för radiofysik Department of Radiations Physics; []
   Nyckelord :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

4. 3. Acoustical properties of earplugs

   Författare :Per Hiselius; Teknisk akustik; []
   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 : In this study an experimental setup for measurements of high impedance objects in ducts, yielding the acoustical Two-Port properties of the object, is applied to earplugs. A frequently used experimental setup for measuring objective acoustical properties of earplugs is that of artificial ears. Great effort is spent on duplicating the human ear. LÄS MER

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

   Författare :Julia Åhlén; Ewert Bengtsson; Jussi Parkkinen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Bildanalys; Colour; Correction; Attenuation; Coefficient; Underwater; Bildanalys; Image analysis; Bildanalys; Computer science;

   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

7. 5. 1060 nm GaAs VCSELs for Extended Reach Optical Interconnects in Data Centers

   Författare :Ewa Simpanen; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-speed modulation; reach; vertical-cavity surface-emitting laser; multi-mode; single-mode; optical interconnect; chromatic dispersion; attenuation;

   Sammanfattning : The data centers of today are increasing in size and are built to accommodate strong data traffic demands while providing sustainably by having clients sharing resources under one roof. Their massive scale puts pressure on the server network topology and has incited a need for data transmission links that are energy efficient and capable to operate at high bit rates with reach up to a few kilometers. LÄS MER