Sökning: "Boltzmann theory"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden Boltzmann theory.

1. 1. First Principles Calculations of Electron Transport and Structural Damage by Intense Irradiation

   Författare :Carlos Ortiz; Olle Eriksson; Mattias Klintenberg; Richard A. London; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Condense matter theory; electronic structure; quasiparticles; GW theory; molecular dynamics; Boltzmann transport; electron transport; impact ionization; structural damage; dielectric response; structural biology; radiation detectors; scintillators; positron emission tommography; Electronic structure; Elektronstruktur; Semiconductor physics; Halvledarfysik; Biological physics; Biologisk fysik; Critical phenomena phase transitions ; Kritiska fenomen fasövergångar ; Functional materials; Funktionella material; Materiefysik; Physics of Matter;

   Sammanfattning : First principle electronic structure theory is used to describe the effect of crystal binding on radiation detectors, electron transport properties, and structural damage induced by intense irradiation. A large database containing general electronic structure results to which data mining algorithms can be applied in the search for new functional materials, a case study is presented for scintillator detector materials. LÄS MER

3. 2. Electronic Transport in Strained Materials

   Författare :Thomas Dziekan; Susanne Mirbt; Olle Eriksson; Per Hyldgaard; Uppsala universitet; []
   Nyckelord :Physics; Conductivity; Strain; Transport; Boltzmann theory; Transition metal; Hydrogen loading; Electronic structure; Density functional theory; Bulk material; Multilayer; Fysik;

   Sammanfattning : In this thesis the conductivity of strained materials has been investigated using density functional theory and a semiclassical transport theory based on the Boltzmann equation.In transition metals trends are reproduced without adjustable parameters. LÄS MER

4. 3. Two Problems on Existence and Approximation Related to the Boltzmann Equation

   Författare :Vladislav Panferov; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boltzmann equation; Povzner type models; diffuse reflection; discrete-velocity models; existence for large data; weak compactness; consistency; convergence; diffuse reflection;

   Sammanfattning : In this thesis, two different types of problems related to the Boltzmann equation of kinetic theory are studied. The first part is devoted to establishing consistency and convergence for discrete-velocity models of the Boltzmann equation. For a new such model, introduced by the author jointly with A. LÄS MER

5. 4. Some numerical and analytical methods for equations of wave propagation and kinetic theory

   Författare :Eva Mossberg; Alexander Bobylev; Giovanni Russo; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; wave propagation; finite difference metods high order methods; Landau-Fokker-Planck equation; Monte-Carlo simulations; Boltzmann equation; hard sphere model; eigenvalue problem; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

   Sammanfattning : This thesis consists of two different parts, related to two different fields in mathematical physics: wave propagation and kinetic theory of gases. Various mathematical and computational problems for equations from these areas are treated. LÄS MER

7. 5. Topics on Generative Models in Machine Learning

   Författare :Carl Ringqvist; Henrik Hult; Thomas Schön; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Latent variable models have been extensively studied within the field of machine learning in recent years. Especially in combination with neural networks and training through back propagation, they have proven successful for a variety of tasks; notably sample gener- ation, clustering, disentanglement and interpolation. LÄS MER