Sökning: "Maximum likelihood"

Visar resultat 21 - 25 av 269 avhandlingar innehållade orden Maximum likelihood.

  1. 21. Searching for Gamma Rays from Galaxy Clusters with the Fermi Large Area Telescope : Cosmic Rays and Dark Matter

    Författare :Stephan Zimmer; Jan Conrad; Christophe Clement; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; galaxy clusters; gamma rays; cosmic rays; dark matter; fermi-lat; likelihood analysis; joint likelihood;

    Sammanfattning : In this licentiate thesis, I report a search for GeV γ rays towards the location of Galaxy clusters. I mainly discuss the results of a search for cosmic-ray (CR) induced γ-ray emission but also briefly elaborate on a related study, searching for Dark Matter (DM)-induced γ-ray emission from Galaxy clusters. LÄS MER

  3. 22. Synchronization for Multicarrier Systems

    Författare :Daniel Landström; Institutionen för elektro- och informationsteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signal processing; Signalbehandling; Frequency estimation; Time estimation; Maximum-Likelihood; Synchronization; OFDM; DMT;

    Sammanfattning : This thesis has synchronization of Multicarrier systems, more specifically Orthogonal Frequency Division Multiplexing (OFDM) systems, as the main theme. The thesis addresses two areas, the first proposing and analyzing time and frequency estimators for OFDM systems, the second investigating more practical issues around these estimators. LÄS MER

  4. 23. Some Aspects on Confirmatory Factor Analysis of Ordinal Variables and Generating Non-normal Data

    Författare :Hao Luo; Fan Yang-Wallentin; Johan Lyhagen; Karl Jöreskog; Marie Wiberg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; confirmatory factor analysis; ordinal variables; maximum likelihood; weighted least squares; polychoric correlation; non-normal data; Fleishman s method; Monte Carlo simulation; Statistics; Statistik; Statistics; Statistik;

    Sammanfattning : This thesis, which consists of five papers, is concerned with various aspects of confirmatory factor analysis (CFA) of ordinal variables and the generation of non-normal data. The first paper studies the performances of different estimation methods used in CFA when ordinal data are encountered. LÄS MER

  5. 24. DSGE Model Estimation and Labor Market Dynamics

    Författare :Glenn Mickelsson; Nils Gottfries; Karl Walentin; Martin M Andreasen; Uppsala universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; DSGE Models; Macroeconomics; Estimation; Uninformative Priors; Maximum Likelihood; Labor Hoarding; US Labor Market; Swedish Micro Data; Economics; Nationalekonomi;

    Sammanfattning : Essay 1: Estimation of DSGE Models with Uninformative PriorsDSGE models are typically estimated using Bayesian methods, but because prior information may be lacking, a number of papers have developed methods for estimation with less informative priors (diffuse priors). This paper takes this development one step further and suggests a method that allows full information maximum likelihood (FIML) estimation of a medium-sized DSGE model. LÄS MER

  7. 25. Knowledge-based speech enhancement

    Författare :Sriram Srinivasan; Bastiaan Kleijn; Rainer Martin; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; speech enhancement; noise reduction; linear predictive coe±cients; autoregressive; codebooks; maximum-likelihood; Bayesian; nonstationary noise; blind source separation.; Telecommunication; Telekommunikation;

    Sammanfattning : Speech is a fundamental means of human communication. In the last several decades, much effort has been devoted to the efficient transmission and storage of speech signals. With advances in technology making mobile communication ubiquitous, communications anywhere has become a reality. LÄS MER