Sökning: "geometrical distortions"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden geometrical distortions.

1. 1. Geometric distortions in MRI based radiotherapy and PET/MRI

   Författare :Josef Lundman; Tufve Nyholm; Anne Larsson; Jörgen Olofsson; Marco Riboldi; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Magnetic resonance imaging; MRI; PET MR; PET MRI; medical imaging; radiotherapy; geometrical distortions; MR-only; MRI-only; radiofysik; radiation physics;

   Sammanfattning : Magnetic resonance imaging (MRI) offers high soft-tissue contrast compared to computed tomography (CT). This contrast is helpful in many cases, not least for delineating tumours for radiotherapy treatment, and has led to increasing use in radiotherapy treatment planning (RTP). LÄS MER

3. 2. SAR Image Focus Errors due to Incorrect Geometrical Positioning in Fast Factorized Back-Projection

   Författare :Annelie Wyholt; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Back-Projection; topography effects; range distortions; Autofocus; SAR;

   Sammanfattning : Synthetic Aperture Radar, SAR, is an aperture synthesis technique to generate an image of the ground from air or space with high resolution. Signal processing is performed in frequency domain with Fourier Transform techniques, or in time domain with Back Projection techniques. LÄS MER

4. 3. Digital process planning of joining by numerical models in the automotive industry

   Författare :Oscar Andersson; Arne Melander; KTH; []
   Nyckelord :Production Engineering; Industriell produktion;

   Sammanfattning : The automotive industry is striving towards reduction of greenhouse gas emission by reducing product weight and improving fuel efficiency of their products. The introduction of lightweight materials have imposed greater pressure not only on the product development but also on manufacturing systems. LÄS MER

5. 4. Sintering simulation framework for 316L stainless steel components manufactured by binder jetting

   Författare :Alberto Cabo Rios; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sintering; sintering modelling; additive manufacturing; binder jetting; stainless steel.; dilatometry;

   Sammanfattning : Binder Jetting (BJT) is an additive manufacturing (AM) technology allowing mass-production of small to medium-size metal components. BJT is a multi-step AM technology, where the geometrical shape of components is provided during the printing step, and the final properties are achieved through a second consolidation step - sintering. LÄS MER

7. 5. Theoretical Description of Electronic Transitions in Large Molecular Systems in the Optical and X-Ray Regions

   Författare :Nanna Holmgaard List; Jacob Kongsted; Hans Jørgen Aagaard Jensen; Roberto Cammi; Jeppe Olsen; Jens Oddershede; Denmark University of Southern Denmark Chemistry and Biology Department of Physics; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polarizable embedding; multiscale modeling; localized electronic transitions; response theory; QM MM; damped linear response; non-dipolar effects; light-matter interactions; multipole expansion; embedding potentials; local field effects; fluorescent proteins; computational chemistry; MCSCF; Teoretisk kemi och biologi; Theoretical Chemistry and Biology;

   Sammanfattning : The size and conformational complexity of proteins and other large systems represent major challenges for today's methods of quantum chemistry.This thesis is centered around the development of new computational tools to gain molecular-level insight into electronic transitions in such systems. LÄS MER