Sökning: "statistik"

Visar resultat 6 - 10 av 1307 avhandlingar innehållade ordet statistik.

  1. 6. Studying earnings trajectories as functional outcomes

    Författare :Kreske Ecker; Xavier de Luna; Lina Schelin; Jose Peña; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; functional data analysis; causal inference; earnings trajectories; simultaneous confidence bands; missing data; Statistics; statistik;

    Sammanfattning : In this thesis, we present methods for studying patterns of income accumulation over time using functional data analysis. This is made possible by the availability of large-scale longitudinal register data in Sweden. LÄS MER

  3. 7. Sensitivity and Uncertainty Analysis Methods : with Applications to a Road Traffic Emission Model

    Författare :Olle Eriksson; Stig Danielsson; Rolf Sundberg; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Emission; Grid; Model; Pollutant; Response surface; Road traffic; Sensitivity analysis; Simulation; Uncertainty analysis; Avgaser; Vägtrafik; Miljöaspekter; Statistics; Statistik;

    Sammanfattning : There is always a need to study the properties of complex input–output systems, properties that may be very difficult to determine. Two such properties are the output’s sensitivity to changes in the inputs and the output’s uncertainty if the inputs are uncertain. LÄS MER

  4. 8. Uncertainty intervals and sensitivity analysis for missing data

    Författare :Minna Genbäck; Xavier de Luna; Elena Stanghellini; Arvid Sjölander; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; missing data; missing not at random; non-ignorable; set identification; uncertainty intervals; sensitivity analysis; self reported health; average causal effect; average causal effect on the treated; mixed-effects models; Statistics; statistik;

    Sammanfattning : In this thesis we develop methods for dealing with missing data in a univariate response variable when estimating regression parameters. Missing outcome data is a problem in a number of applications, one of which is follow-up studies. LÄS MER

  5. 9. Methods for longitudinal brain imaging studies with dropout

    Författare :Tetiana Gorbach; Xavier de Luna; Anders Lundquist; Martin A. Lindquist; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Missing data; nonignorable dropout; sensitivity analysis; uncertainty intervals; pattern-mixture models; aging; cognition; MRI; brain structure; resting-state functional connectivity; Statistics; statistik;

    Sammanfattning : One of the challenges in aging research is to understand the brain mechanisms that underlie cognitive development in older adults. Such aging processes are investigated in longitudinal studies, where the within-individual changes over time are observed. However, several methodological issues exist in longitudinal analyses. LÄS MER

  7. 10. Generalized linear models with clustered data

    Författare :Henrik Holmberg; Erling Häggström Lundevaller; Göran Broström; Douglas Bates; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Statistics; statistik;

    Sammanfattning : In situations where a large data set is partitioned into many relatively small groups, and where the members within a group have some common unmeasured characteristics, the number of parameters requiring estimation tends to increase with sample size if a fixed effects model is applied. This fact causes the assumptions underlying asymptotic results to be violated. LÄS MER