Sökning: "diffusion spectrum"
Visar resultat 1 - 5 av 48 avhandlingar innehållade orden diffusion spectrum.
1. Heterogeneous Materials - Diffusion, Laplace spectrum and NMR
Sammanfattning : Relations to the effective diffusion constant and the relaxation rate of the time-dependent diffusion coefficient for porous systems are derived from the Laplace operator spectrum. The Padé approximation is then explained in terms of the Laplace operator spectrum. LÄS MER
2. Applications of diffusion MRI: Tensor-valued encoding, time-dependent diffusion, and histological validation
Sammanfattning : Diffusion MRI (dMRI) sensitizes the MR signal to the diffusion of water molecules at the microscopic level and thereby non-invasively probes tissue microstructure. This is relevant when determining biological properties of tissues, for example, cancer type and its malignancy. LÄS MER
3. Heterogeneous Materials - Diffusion, Laplace Spectrum, and Nuclear Magnetic Resonance
Sammanfattning : In this thesis diffusion in heterogeneous materials is studied using spectral analysisof the Laplace operator. Relations to the effective diffusion constant and therelaxation rate of the time-dependent diffusion coefficient for porous systems arederived from the Laplace operator’s spectrum. LÄS MER
4. Distributed Detection in Cognitive Radio Networks
Sammanfattning : One of the problems with the modern radio communication is the lack of availableradio frequencies. Recent studies have shown that, while the available licensed radiospectrum becomes more occupied, the assigned spectrum is significantly underutilized. LÄS MER
5. Atomic Spectroscopy on Fusion Relevant Ions and Studies of Light Impurities in the JET Tokamak
Sammanfattning : The spectrum and energy levels C IV and the 3l4l' system of the Mg-like ions in the iron group elements has been investigated. This has led to several hundred identified transitions, many of them previously unknown. LÄS MER
