Sökning: "gibbs sampling"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden gibbs sampling.

1. 1. Statistical models of TF/DNA interaction

   Författare :Aymeric Fouquier d'Herouel; Erik Aurell; Otto Berg; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gene expression; regulation; transcription factor; binding motif; matrix representations; gibbs sampling; binding affinity; non-specific binding; Biological physics; Biologisk fysik;

   Sammanfattning : Gene expression is regulated in response to metabolic necessities and environmental changes throughout the life of a cell. A major part of this regulation is governed at the level of transcription, deciding whether messengers to specific genes are produced or not. LÄS MER

3. 2. Structural Models of Network Contacts Between Actors Governed by Activity and Attraction

   Författare :Zhi Geng; Statistiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Directed graph; Ego-nets; EM algorithm; Gibbs sampling; Multinomial distribution; Hypergeometric distribution; Vertex covariates; Clustering coefficient; Taylor expansion;

   Sammanfattning : This thesis consists of five papers on the subject of statistical modeling of stochastic networks. The NG-model proposed in Paper I combines a block structure with parameters that capture the identities of vertices and thus the new approach stresses the concept of ego-nets, which describes the structure around identified vertices. LÄS MER

4. 3. Particle filters and Markov chains for learning of dynamical systems

   Författare :Fredrik Lindsten; Thomas B. Schön; Lennart Ljung; Fredrik Gustafsson; Arnaud Doucet; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Bayesian learning; System identification; Sequential Monte Carlo; Markov chain Monte Carlo; Particle MCMC; Particle filters; Particle smoothers;

   Sammanfattning : Sequential Monte Carlo (SMC) and Markov chain Monte Carlo (MCMC) methods provide computational tools for systematic inference and learning in complex dynamical systems, such as nonlinear and non-Gaussian state-space models. This thesis builds upon several methodological advances within these classes of Monte Carlo methods. LÄS MER

5. 4. Bayesian Models for Multilingual Word Alignment

   Författare :Robert Östling; Mats Wirén; Ola Knutsson; Jörg Tiedemann; Sharon Goldwater; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; word alignment; parallel text; Bayesian models; MCMC; linguistic typology; sign language; annotation transfer; transfer learning; Linguistics; lingvistik;

   Sammanfattning : In this thesis I explore Bayesian models for word alignment, how they can be improved through joint annotation transfer, and how they can be extended to parallel texts in more than two languages. In addition to these general methodological developments, I apply the algorithms to problems from sign language research and linguistic typology. LÄS MER

7. 5. Semi Markov chain Monte Carlo

   Författare :Håkan Ljung; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Adaptive simulation; error-in-the-variables; Kullback-Leibler divergence; Markov chain simulation; Markov chain Monte Carlo; semi-regenerative; MATEMATIK; MATHEMATICS; MATEMATIK; matematisk statistik; Mathematical Statistics;

   Sammanfattning : The first paper introduces a new simulation technique, called semi Markov chain Monte Carlo, suitable for estimating the expectation of a fixed function over a distribution π, Eπf(χ). Given a Markov chain with stationary distribution p, for example a Markov chain corresponding to a Markov chain Monte Carlo algorithm, an embedded Markov renewal process is used to divide the trajectory into different parts. LÄS MER