Sökning: "Statistics as Topic"

Visar resultat 1 - 5 av 55 avhandlingar innehållade orden Statistics as Topic.

1. 1. Bayesian Inference in Large Data Problems

   Författare :Matias Quiroz; Mattias Villani; Bani K. Mallick; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bayesian inference; Large data sets; Markov chain Monte Carlo; Survey sampling; Pseudo-marginal MCMC; Delayed acceptance MCMC; Statistics; statistik;

   Sammanfattning : In the last decade or so, there has been a dramatic increase in storage facilities and the possibility of processing huge amounts of data. This has made large high-quality data sets widely accessible for practitioners. This technology innovation seriously challenges traditional modeling and inference methodology. LÄS MER

3. 2. Space-Time Prediction of Ocean Winds

   Författare :Anders Malmberg; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; operations research; image warping; thin-plate splines.; near-surface ocean winds; variogram parameters; Space-time Kalman filtering; real-time assimilation; residual wind speed; actuarial mathematics; programming; Statistik; operationsanalys; programmering; aktuariematematik;

   Sammanfattning : The topic of this thesis is inspired by an experiment in which a vessel, laying a submarine cable, was provided with forecasts overlaid with satellite observations of significant wave height. During the operation, the vessel was close to an adverse weather area and the personnel on board could confirm that the forecast was not as close to the "ground truth" as the satellite observation was. LÄS MER

4. 3. Essays on Sample Surveys : Design and Estimation

   Författare :Edgar Bueno; Per Gösta Andersson; Maria Giovanna Ranalli; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; GREG estimator; mixture distribution; probability proportional to size sampling; sampling algorithms; sampling design; sampling strategy; survey sampling; stratified sampling; Statistics; statistik;

   Sammanfattning : Sampling is a core stage in every survey. A sampling design carefully elaborated may imply not only a more accurate estimation of the parameters of interest, but also a reduction in the required sample size in a study. In this thesis we consider two particular but connected subjects. LÄS MER

5. 4. Test Design for Mean Ability Growth and Optimal Item Calibration for Achievement Tests

   Författare :Jonas Bjermo; Frank Miller; Marie Wiberg; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; test design; item response theory; optimal experimental design; SweSAT; item calibration; vertical scaling; ability growth; computerized adaptive tests; Statistics; statistik;

   Sammanfattning : In this thesis, we examine two topics in the area of educational measurement. The first topic studies how to best design two achievement tests with common items such that a population mean-ability growth is measured as precisely as possible. The second examines how to calibrate newly developed test items optimally. LÄS MER

7. 5. Optimal Design of Experiments for the Quadratic Logistic Model

   Författare :Ellinor Fackle Fornius; Hans Nyquist; Christos Kitsos; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Logistic regression; D-optimality; c-optimality; Canonical design space; Maximum likelihood estimation; Sequential design; Stochastic approximation; Statistics; Statistik; statistik; Statistics;

   Sammanfattning : Optimal design of experiments for binary data is the topic of this thesis. A particular logistic model including a quadratic term in the linear predictor is considered. Determining an optimal design for this model is complicated by the fact that the optimal design is dependent on the unknown true parameters. LÄS MER