Sökning: "echo"

Visar resultat 11 - 15 av 191 avhandlingar innehållade ordet echo.

  1. 11. ASIC Implementation of a Delayless Acoustic Echo Canceller: Architecture and Arithmetic

    Författare :Anders Berkeman; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; Signalbehandling; Digital Arithmetic; Acoustic Echo Cancellation; Hardware Implementation; Digital ASIC Design; Digital Signal Processing;

    Sammanfattning : Application specific digital signal processors are superior compared to standard digital signal processors in a number of application fields, mainly due to high throughput and low power consumption traded for flexibility. This thesis deals with two areas related to hardware implementation of custom digital signal processors: design methodology and efficient implementation of arithmetic circuits. LÄS MER

  3. 12. MODELLING AND SIMULATION OF ELASTIC & PLASTIC BEHAVIOUR OF PROPAGATING IMPACT WAVE : Impact- echo and Explosive welding process development

    Författare :Mohammad Tabatabaee Ghomi; Jafar Mahmoudi; Golamhoosin Liaghat; Hamid Bahai; Mälardalens högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy- and Environmental Engineering; energi- och miljöteknik;

    Sammanfattning : A force that is applied dynamically in a short period of time is called an impact force (shock wave). Due to the concentrated application of force on a small area in a fraction of a second, unique applications have emerged that other types of loadings are not capable of performing. LÄS MER

  4. 13. Magnetic resonance imaging with ultrashort echo time as a substitute for X-ray computed tomography

    Författare :Adam Johansson; Tufve Nyholm; Karlsson Mikael; James Balter; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetic resonance imaging; computed tomography substitute; ultrashort echo time; parallel imaging; radial imaging; radiofysik; radiation physics;

    Sammanfattning : Radiotherapy dose calculations have evolved from simple factor based methods performed with pen and paper, into computationally intensive simulations based on Monte Carlo theory and energy deposition kernel convolution.Similarly, in the field of positron emission tomography (PET), attenuation correction, which was originally omitted entirely, is now a crucial component of any PET reconstruction algorithm. LÄS MER

  5. 14. Two cases of nonlinear waves in plasma : echo in weak turbulence and solitary drift vortices

    Författare :Jonas Nycander; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : .... LÄS MER

  7. 15. Gradient echo-based quantitative MRI of human brain at 7T : Mapping of T1, MT saturation and local flip angle

    Författare :Hampus Olsson; Lund Medicinsk strålningsfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MR studies; magnetic resonance MR ; 7 Tesla; T1 mapping; magnetization transfer saturation; Flip angle mapping; spoiled gradient echo; MR studies; magnetic resonance MR ; 7T; T1 mapping; magnetization transfer saturation; Flip angle mapping; spoiled gradient echo;

    Sammanfattning : Quantitative MRI (qMRI) refers to the process of deriving maps of MR contrast parameters, such as relaxation times, from conventional images. If the qMRI maps have a high degree of precision and a low degree of bias, they can be compared longitudinally, across subjects, and (ideally) between measurement protocols and research sites. LÄS MER