Sökning: "Variational method"

Visar resultat 16 - 20 av 84 avhandlingar innehållade orden Variational method.

1. 16. Statistical inference with deep latent variable models

   Författare :Najmeh Abiri; Beräkningsbiologi och biologisk fysik - Genomgår omorganisation; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Deep Learning; Generative Models; Variational Inference; Missing data; Imputation; Fysicumarkivet A:2019:Abiri;

   Sammanfattning : Finding a suitable way to represent information in a dataset is one of the fundamental problems in Artificial Intelligence. With limited labeled information, unsupervised learning algorithms help to discover useful representations. LÄS MER

3. 17. Optimal Switching Problems and Related Equations

   Författare :Marcus Olofsson; Kaj Nyström; Saïd Hamadène; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; optimal switching; stochastic control; variational inequalities; backward stochastic differential equations; incomplete information; stochastic filtering; Mathematics; Matematik;

   Sammanfattning : This thesis consists of five scientific papers dealing with equations related to the optimal switching problem, mainly backward stochastic differential equations and variational inequalities. Besides the scientific papers, the thesis contains an introduction to the optimal switching problem and a brief outline of possible topics for future research. LÄS MER

4. 18. Correlated materials : models and methods

   Författare :Hugo Strand; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; correlated electrons; Hubbard model; multiband Hubbard model; dynamical mean field theory; exact diagonalization; Landau theory; Mott metal-insulator transition; Gutzwiller method; many-body point group symmetry; ironchalcogenides; Kanamori interaction; Slater-Condon interaction;

   Sammanfattning : This thesis encompass a series of studies on methods and models for electron systems with local interactions, relevant for correlated materials. The first study focus on the canonical model for local correlation, the Hubbard model. LÄS MER

5. 19. Wave interactions by Hamiltonian methods

   Författare :Krister Wiklund; Umeå universitet; []
   Nyckelord :Hamiltonian formulation; wave interaction; stability; variational principles;

   Sammanfattning : This thesis is devoted to the description of fluids and gases from a Hamiltonian point of view. The method we apply is a development of the theory invented by Hamilton (1805-1865). The original formulation is restricted to a certain family of dynamical variables; the canonical variables. LÄS MER

7. 20. Statistical Segmentation and Registration of Medical Ultrasound Data

   Författare :Mattias Hansson; Matematik LTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Registration; Segmentation; Feature descriptor; Statistical image and signal processing; Medical ultrasound; Variational methods; Mixture model; Bayesian; Markov Chain Monte Carlo; Similarity measur;

   Sammanfattning : The interpretation of ultrasonic imagery is typically not straightforward and of quite subjective nature and therefore strongly dependent on the expertise of its users. Thus the development of algorithms which aid in the interpretation of ultrasonic data is a highly relevant topic. LÄS MER