Search for dissertations about: "variational approaches"

Showing result 1 - 5 of 23 swedish dissertations containing the words variational approaches.

2. 1. Variational Inference of Dynamic Factor Models

   Author : Erik Spånberg; Pär Stockhammar; Gebrenegus Ghilagaber; Sune Karlsson; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamic factor models; variational inference; missing data; nowcasting; expectation maximization; statistik; Statistics;

   Abstract : When we make difficult and crucial decisions, forecasts are powerful and important tools. For that purpose, statistical models can be our most effective aid. Ideally, these models can incorporate large sets of multifaceted data. READ MORE

4. 2. Equilibrium and Dynamics on Complex Networkds

   Author : Gino Del Ferraro; Erik Aurell; Bernard Derrida; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Statistical mechanics; complex networks; spin systems; non equilibrium dynamics; generalized belief propagation; message passing; cavity method; variational approaches; Fysik; Physics;

   Abstract : Complex networks are an important class of models used to describe the behaviour of a very broad category of systems which appear in different fields of science ranging from physics, biology and statistics to computer science and other disciplines. This set of models includes spin systems on a graph, neural networks, decision networks, spreading disease, financial trade, social networks and all systems which can be represented as interacting agents on some sort of graph architecture. READ MORE

5. 3. Machine learning using approximate inference : Variational and sequential Monte Carlo methods

   Author : Christian Andersson Naesseth; Thomas Schön; Fredrik Lindsten; Iain Murray; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : Automatic decision making and pattern recognition under uncertainty are difficult tasks that are ubiquitous in our everyday life. The systems we design, and technology we develop, requires us to coherently represent and work with uncertainty in data. READ MORE

6. 4. New Approaches to Large-Scale Electronic Structure Calculations

   Author : Francesco Aquilante; Beräkningskemi; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Theoretical chemistry; orbital localization; electron correlation; analytic gradients; Cholesky decomposition; density fitting; quantum chemistry; Teoretisk kemi; kvantkemi;

   Abstract : Recent years have witnessed a growing interest of the scientific community for the use of ab initio and density functional theory methods in theoretical studies of molecules containing many atoms. However, the `scaling wall' of some of the most accurate of such methods is often an obstacle for their applicability to systems of real-life interest, e. READ MORE

7. 5. Static and Dynamic Correlation Effects in Atoms

   Author : Nils-Erik Dahlen; Matematisk fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; magnetic and optical properties; electrical; Condensed matter:electronic structure; relaxation; magnetic resonance; supraconductors; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; Atom- och molekylärfysik; Atomic and molecular physics; spektroskopi; magnetisk resonans; egenskaper elektriska; supraledare; magnetiska och optiska ; variational energies; double ionization; Electron correlation; laser-atom interaction; Fysicumarkivet A:2002:Dahlen; conserving approximations; Green s functions; GW-approximation;

   Abstract : The thesis considers the effects of electron correlation by studying the two opposite limits of atoms in the ground state and atoms in strong laser pulses. Computational methods and theoretical approaches differ significantly due to the different physical processes that are studied in these two cases. READ MORE