Sökning: "parameterisation"

Visar resultat 6 - 10 av 36 avhandlingar innehållade ordet parameterisation.

1. 6. Roughness lengths and roughness sublayer corrections in partly forested regions

   Författare :Meelis Mölder; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; flux parameterisation; profile measurements; radiation temperature; displacementheight; barley; pasture; Geovetenskap; Earth sciences; Geovetenskap; Hydrology; hydrologi;

   Sammanfattning : Questions related to water resources management and climate change at regional to global scales have inspired research about processes governing exchange of water, heat and carbon between land and atmosphere. The concept of roughness length is fundamental in deduction of bulk transfer relations from the generally accepted Monin-Obukhov similarity theory for this exchange. LÄS MER

3. 7. Geometry parameterisation and response surface-based shape optimisation of aero-engine compressors

   Författare :Jörgen Burman; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : The main goal in jet engine design is to achieve light, compact and highly efficient systems while reducing the cost and design times. Traditionally, the design has been based on trial-and-error procedures, which count on the skills and experience of the designer to suggest design improvements. LÄS MER

4. 8. Submicrometre aerosol emissions from sea spray and road traffic

   Författare :Monica Mårtensson; Douglas Nilsson; Christer Johansson; Michael Smith; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eddy covariance method; aerosol emissions; submicrometre sea salt parameterisation; primary marine organic aerosols; sea spray; road traffic emission factors; air-sea exchange; aerosol dynamics model; internal aerosol mixing; combustion aerosols; Atmosphere and hydrosphere sciences; Atmosfärs- och hydrosfärsvetenskap; atmosfärvetenskap; Atmospheric Sciences;

   Sammanfattning : The uncertainty of the climate and health effects of aerosols is still large, one important reason being lack of knowledge of the primary emissions. This thesis combines laboratory and field experiments, and process modelling in an effort to better quantify the submicrometre aerosol emissions and to understand some of the processes in the atmosphere. LÄS MER

5. 9. Automatic Shape Modelling with Applications in Medical Imaging

   Författare :Anders Ericsson; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; heart-infarction; lung-embolie; Parkinson; DaTSCAN; SPECT; SCINT; affine shape; MDL; automatic shape models; Deformable models; active shape; Mathematics; Matematik;

   Sammanfattning : This thesis consists of two parts. The first part is devoted to automatic shape analysis and the second part is devoted to decision support systems in medical imaging. Shape models are widely used in segmentation and shape analysis. The thesis begins with a review of deformable models and the preliminaries of shape modelling. LÄS MER

7. 10. Experimental investigation of snow metamorphism at near-surface layers

   Författare :Lavan Kumar Eppanapelli; Mikael Sjödahl; Johan Casselgren; Arne Instanes; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Snow metamorphism; NIR reflectance; Snow and Ice; Radiative transfer equation; Paramterization; Snow properties; Tomography; Snow microstructure; Experimentell mekanik; Experimental Mechanics;

   Sammanfattning : Snow metamorphism is a direct objective in many snow research areas, and its charac-terisation is a major challenge in areas including winter road maintenance, detection of icing on wind turbine blades, and snow quality mapping for skiing. A common effect of snow metamorphism is compaction, which can be investigated from the associated vari-ations in physical properties of snow. LÄS MER