Sökning: "spectral properties"

Visar resultat 1 - 5 av 421 avhandlingar innehållade orden spectral properties.

1. 1. Advanced Spectral Analysis with Applications

   Författare :Niclas Sandgren; Peter Stoica; Thomas L. Marzetta; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency-selective spectral analysis; damped sinusoidal model; prior knowledge; multichannel spectroscopy; phantom experimental data; in-vivo in-vitro data analysis; area-selective analysis; cepstrum thresholding; total-variance reduction; two-dimensional spectral estimation; spectral smoothing; irregular sampling; CARMA signals; Signal processing; Signalbehandling;

   Sammanfattning : Spectral analysis has advanced the last decades as a signal processing tool to extract significant information about certain properties of measured data. The practical use of spectral analysis techniques in time-series analysis has been emphasized in the immense amount of previous literature in the field and by a rapidly growing number of applications. LÄS MER

3. 2. Spectral Moment Problems : Generalizations, Implementation and Tuning

   Författare :Enrico Avventi; Anders Lindquist; Giorgio Picci; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optimization; systems theory; Optimeringslära; systemteori;

   Sammanfattning : Spectral moment interpolation find application in a wide array of use cases: robust control, system identification, model reduction to name the most notable ones. This thesis aims to expand the theory of such methods in three different directions. The first main contribution concerns the practical applicability. LÄS MER

4. 3. Cohesive and Spectroscopic properties of the Lanthanides within the Hubbard I Approximation

   Författare :Inka Laura Marie Locht; Igor Di Marco; Olle Eriksson; Annalisa Fasolino; Mikhail I. Katsnelson; Tim Wehling; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lantanides; rare earths; cohesive properties; volume; bulk modulus; magnetism; magnetic properties; photoemission spectroscopy; XPS; BIS; Hubbard I Approximation; DMFT; DFT; RSPt; Full Potential Linear Muffin-tin orbitals; 4f electrons; localization; bonding; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : We describe the rare-earth elements using the Hubbard I approximation. We show that the theory reproduces the cohesive properties, like the volume and bulk modulus, and we find an excellent agreement between theory and experiment for the (inverse) photo emission spectra of the valence band. LÄS MER

5. 4. Geometrical controls on spectral induced polarization in time and frequency domain

   Författare :Sara Johansson; Teknisk geologi; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spectral induced polarization; Microstructure; Electrical properties; Tomography; Multiscale;

   Sammanfattning : What can we learn by transmitting electrical currents through electrodes in the ground? Geophysical methods can help us to locate the bedrock, valuable mineral ores, remains of ancient buildings and many other secrets hiding below the surface. However, it is not only the universal interest for the unknown that drives the geophysical research forward. LÄS MER

7. 5. Time Spectral Methods - Towards Plasma Turbulence Modelling

   Författare :Kristoffer Lindvall; Jan Scheffel; Carl Sovinec; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Fusion; Turbulence; Micro-instabilities; Time-spectral; Navier-Stokes; MHD; Weiland model; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Energy comes in two forms; potential energy and kinetic energy. Energyis stored as potential energy and released in the form of kinetic energy. This process of storage and release is the basic strategy of all energy alternatives in use today. This applies to solar, wind, fossil fuels, and the list goes on. LÄS MER