Sökning: "Magnus Herberthson"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Magnus Herberthson.
1. Multipole moments of axisymmetric spacetimes
Sammanfattning : In this thesis we study multipole moments of axisymmetric spacetimes. Using the recursive definition of the multipole moments of Geroch and Hansen we develop a method for computing all multipole moments of a stationary axisymmetric spacetime without the use of a recursion. LÄS MER
2. Conformal Einstein spaces and Bach tensor generalization in n dimensions
Sammanfattning : In this thesis we investigate necessary and su±cient conditions for an n-dimensional space, n ≥ 4, to be locally conformal to an Einstein space. After reviewing the classical results derived in tensors we consider the four-dimensional spinor result of Kozameh, Newman and Tod. LÄS MER
3. Diffusion MRI with generalised gradient waveforms : methods, models, and neuroimaging applications
Sammanfattning : The incessant, random motion of water molecules within biological tissues reveals unique information about the tissues’ structural and functional characteristics. Diffusion magnetic resonance imaging is sensitive to this random motion, and since the mid-1990s it has been extensively employed for studying the human brain. LÄS MER
4. Manifold learning and representations for image analysis and visualization
Sammanfattning : We present a novel method for manifold learning, i.e. identification of the low-dimensional manifold-like structure present in a set of data points in a possibly high-dimensional space. The main idea is derived from the concept of Riemannian normal coordinates. LÄS MER
5. Manifolds in Image Science and Visualization
Sammanfattning : A Riemannian manifold is a mathematical concept that generalizes curved surfaces to higher dimensions, giving a precise meaning to concepts like angle, length, area, volume and curvature. A glimpse of the consequences of a non-flat geometry is given on the sphere, where the shortest path between two points – a geodesic – is along a great circle. LÄS MER