Search for dissertations about: "Statistik"

Showing result 1 - 5 of 1248 swedish dissertations containing the word Statistik.

  1. 1. Contributions to the Theory of Measures of Association for Ordinal Variables

    Author : Joakim Ekström; Rolf Larsson; Albert Satorra; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Statistics; Statistik; Statistics; statistik;

    Abstract : In this thesis, we consider measures of association for ordinal variables from a theoretical perspective. In particular, we study the phi-coefficient, the tetrachoric correlation coefficient and the polychoric correlation coefficient. READ MORE

  2. 2. Monotonic and Semiparametric Regression for the Detection of Trends in Environmental Quality Data

    Author : Mohamed Hussian; Anders Grimvall; Ali Hadi; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Normalisation; Monotonic; Semiparametric; Temporal trends; fluctuations; global; local; Matematisk statistik; Icke-parametriska metoder; Statistics; Statistik;

    Abstract : Natural fluctuations in the state of the environment can long conceal or distort important trends in the human impact on our ecosystems. Accordingly, there is increasing interest in statistical normalisation techniques that can clarify the anthropogenic effects by removing meteorologically driven fluctuations and other natural variation in time series of environmental quality data. READ MORE

  3. 3. Methods for interval-censored data and testing for stochastic dominance

    Author : Angel G. Angelov; Magnus Ekström; Maria Karlsson; Bengt Kriström; Per Johansson; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Interval-censored data; Informative censoring; Self-selected intervals; Questionnaire-based studies; Maximum likelihood; Permutation test; Two-sample test; Stochastic dominance; Four-decision test; Statistics; statistik;

    Abstract : This thesis includes four papers: the first three of them are concerned with methods for interval-censored data, while the forth paper is devoted to testing for stochastic dominance.In many studies, the variable of interest is observed to lie within an interval instead of being observed exactly, i.e. READ MORE

  4. 4. Estimation of hazard ratios from observational data with applications related to stroke

    Author : Guilherme Barros; Jenny Häggström; Marie Eriksson; Daniel Nevo; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; survival analysis; causal inference; hazard ratios; marginal hazard ratio; stroke; balancing; Statistics; statistik;

    Abstract : The objective of this thesis is to examine some challenges that may emerge when conducting time-to-event studies based on observational data. Time-to-event (also called survival) is a setting that involves analyzing how different factors may influence the length of time until an individual experiences the event of interest. READ MORE

  5. 5. Characterizing Temporal Changes and Inter-Site Correlations in Daily and Sub-Daily Precipitation Extremes

    Author : Agne Burauskaite-Harju; Anders Grimvall; Marian Scott; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Klimatförändringar; matematiska modeller; Statistics; Statistik;

    Abstract : Information on weather extremes is essential for risk awareness in planning of infrastructure and agriculture, and it may also playa key role in our ability to adapt to recurrent or more or less unique extreme events. This thesis reports new statistical methodologies that can aid climate risk assessment under conditions of climate change. READ MORE