Visar resultat 1 - 5 av 1274 avhandlingar innehållade ordet statistik.
Sammanfattning : 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. LÄS MER
2. Monotonic and Semiparametric Regression for the Detection of Trends in Environmental Quality Data
Sammanfattning : 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. LÄS MER
Sammanfattning : 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. LÄS MER
Sammanfattning : 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. LÄS MER
5. Characterizing Temporal Changes and Inter-Site Correlations in Daily and Sub-Daily Precipitation Extremes
Sammanfattning : 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. LÄS MER