Sökning: "branching process"

Visar resultat 11 - 15 av 68 avhandlingar innehållade orden branching process.

1. 11. Stochastic epidemics on random networks and competition in growth

   Författare :Carolina Fransson; Pieter Trapman; Daniel Ahlberg; Julia Komjathy; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; random graphs; branching processes; SIR epidemics; malthusian parameter; urn model; matematisk statistik; Mathematical Statistics;

   Sammanfattning : The COVID-19 pandemic has dramatically demonstrated the importance of epidemic models in understanding and predicting disease spread and in assessing the effectiveness of interventions. The overarching topic of this thesis is stochastic epidemic modelling, with the main focus on the role of the underlying social structure in infectious disease spread. LÄS MER

3. 12. Ecological and evolutionary assembly processes and metacommunity structure

   Författare :Mikael Pontarp; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Community; metacommunity; phylogenetic signal; ecology; evolution; assembly process; marine bacteria; habitat filtering; competition; mathematical modeling; simulation; eco-evolutionary;

   Sammanfattning : This thesis aims to elucidate the link between abiotic and biotic effects and biogeographical contingencies, eco-evolutionary assembly processes, and community structure in a spatially explicit metacommunity framework. To this end, we used structure analysis of naturally sampled and experimentally manipulated marine bacterial communities and mathematical eco-evolutionary modeling and simulations of metacommunity assembly. LÄS MER

4. 13. Statistical Modelling of Cell Cycle Dynamics Analysis and Interpretation of BrdUrd DNA FCM-Derived Data

   Författare :Sara Larsson Lönn; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; G2 phase duration; DNA replication; flow cytometry; Natural science; Naturvetenskap; S phase duration; DNA distribution; branching processes; cell cycle kinetics;

   Sammanfattning : It it of great importance to increase the knowledge of various cell cycle kinetic parameters and the objective of this thesis is to use stochastic models to interpret Bromodeoxyuridine (BrdUrd) DNA Flow Cytometry (FCM) derived data in order to estimate such parameters. The cell cycle is the process of growth and division that is essential for an organism to increase in size. LÄS MER

5. 14. Uncertainty Estimation in Models of Multivariate Trait Evolution on Given Phylogenies

   Författare :Woodrow Hao Chi Kiang; Krzysztof Bartoszek; Fredrik Ronquist; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Phylogenetic comparative methods; Branching stochastic processes; Fylogenetiska jämförande metoder; Förgrenade stokastiska processer;

   Sammanfattning : Phylogenetic comparative methods are a set of statistical methods that model the evolutionary history of species, especially in the context where one has data on certain traits of related extant species that have evolved over a phylogenetic tree in accordance to an underlying stochastic process. This thesis presents a Hessian-based closed-form asymptotic confidence region that covers a wide family of Gaussian continuous-trait evolution models; the result has been implemented in an R package. LÄS MER

7. 15. Asymptotic distribution theory for some test statistics in autoregressive and Galton-Watson processes

   Författare :Rolf Larsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Feynman-Kac’ formula; Saddlepoint approximation.; matematisk statistik; Mathematical Statistics;

   Sammanfattning : In this thesis, we study asymptotic distributions of some unit root test statistics in autoregressive processes. We then generalize, at first to the situation when the true parameter value is close to one^(thenear integrated case), and secondly to the corresponding test problems in the Galton-Watson process (i.e. LÄS MER