Sökning: "spatial spectral analysis"

Visar resultat 11 - 15 av 78 avhandlingar innehållade orden spatial spectral analysis.

1. 11. Efficient Solvers for Space-Time Discontinuous Galerkin Spectral Element Methods

   Författare :Lea Miko Versbach; Numerisk analys; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Discontinuous Galerkin Method; Spectral Element Method; Finite Volume Method; Implicit Schemes; Preconditioner; Multigrid Method; Space-Time; Lobatto IIIC Method; Local Fourier Analysis;

   Sammanfattning : In this thesis we study efficient solvers for space-time discontinuous Galerkin spectral element methods (DG-SEM). These discretizations result in fully implicit schemes of variable order in both spatial and temporal directions. LÄS MER

3. 12. Global stability analysis of three-dimensional boundary layer flows

   Författare :Mattias Brynjell-Rahkola; Dan Henningson; Philipp Schlatter; Ardeshir Hanifi; Spencer Sherwin; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic stability; transition to turbulence; global analysis; boundary layers; roughness; laminar flow control; Stokes Laplace preconditioner; optimal forcing; crossflow vortices; Ginzburg-Landau; Falkner-Skan-Cooke; Blasius; lid-driven cavity;

   Sammanfattning : This thesis considers the stability and transition of incompressible boundary layers. In particular, the Falkner–Skan–Cooke boundary layer subject to a cylindrical surface roughness, and the Blasius boundary layer with applied localized suction are investigated. LÄS MER

4. 13. Multivariate Measurements and Chemical Imaging of Organic Compounds

   Författare :Johan Engelbrektsson; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Image analysis; Spectroscopy; Hyperspectral; Chemical Imaging; PCA; PLS; SERS; Wavelet Transform; Multivariate analysis;

   Sammanfattning : Chemical imaging is an emerging analytical technique, based on the interplay between, most often, spectroscopic measurements and advanced evaluation methodology. With this we can study the distribution of chemical compounds in different compartments, such as individual cells and pharmaceutical tablets. LÄS MER

5. 14. Inferring Land Use from Remote Sensing Imagery : A context-based approach

   Författare :Michael Meinild Nielsen; Bo Malmberg; Anders Wästfelt; Douglas A. Stow; Stockholms universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; land use; remote sensing; urban remote sensing; image analysis; segmentation; spatial context; land cover; land cover configuration; farming types; bark beetle; dead trees; forest inventory; kulturgeografi; Human Geography;

   Sammanfattning : This doctoral thesis investigates the potential of classification methods based on spatial context to infer specific forms of land use from remote sensing data. The problem is that some types of land use are characterized by a complex configuration of land covers that traditional per-pixel based methods have problems classifying due to spectral heterogeneity. LÄS MER

7. 15. Topographic Control of Groundwater Flow

   Författare :Lars Marklund; Anders Wörman; Shulan Xu; Roy Haggerty; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Groundwater; Modeling; Topography; Spectral analysis; Fourier series; Exact solu-tions; Multi-scale; Grundvatten; Modellering; Topografi; Spektralanalys; Fourier serier; Analytisk lösning; Flerskalig; Hydrology; Hydrologi; Environmental engineering; Miljöteknik;

   Sammanfattning : Gravity is the main driving force for groundwater flow, and both landscape topography and geology distribute the effects of gravity on groundwater flow.  The groundwater table defines the distribution of the potential energy of the water. LÄS MER