Search for dissertations about: "stratified sampling"

Showing result 1 - 5 of 26 swedish dissertations containing the words stratified sampling.

  1. 1. Essays on Sample Surveys : Design and Estimation

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

    Abstract : 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. READ MORE

  2. 2. Challenges and Advantages of Stratified Combustion in Gasoline Direct-Injected Engines

    Author : Anders Johansson; Chalmers University of Technology; []
    Keywords : TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; Particulate Mass; SGDI; Particulate Number; Direct-Injected; GDI; Particulate Sampling; Spray-Guided; Particulates; Stratified Charge; Gasoline; DI;

    Abstract : The modern world is based on an extensive transport network in which passenger vehicles play a major role. Although passenger vehicles have improved significantly in recent decades, they still contribute to the pollution of our environment and global warming. Consequently, new ways of reducing their emissions are needed. READ MORE

  3. 3. Estimating Probability Distribution by doing Computer Experiments

    Author : Gunnar Kjell; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Keywords : computer simulations; seismic verification; response spectrum prediction; stratified sampling; latin hypercube sampling; variance reduction; variance estimation; seismic verification;

    Abstract : In almost every field of engineering, advanced computer programs are used. In many cases only the probability distributions of the input variables to the programs are known. Sometimes stochastic processes are used as input, for example if the stresses in a construction due to an earthquake are to be calculated. READ MORE

  4. 4. HIV preventive interventions, sampling methods and sexual risk behaviour among men who have sex with men

    Author : Susanne Strömdahl; Karolinska Institutet; Karolinska Institutet; []
    Keywords : MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; HIV prevention;

    Abstract : Background: Gay, bisexual and other men who have sex with men (MSM) are at high risk of HIV globally. HIV rates among MSM in Europe show increasing trends, in contrast to declining trends in the general population. During the last five years, an increase in reported HIV cases among foreign-born MSM have been observed in Sweden. READ MORE

  5. 5. Numerical analysis for random processes and fields and related design problems

    Author : Konrad Abramowicz; Oleg Seleznjev; Krzysztof Podgórski; Umeå universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; stochastic processes; random fields; approximation; numerical integration; Hermite splines; piecewise linear interpolator; local stationarity; point singularity; stratified Monte Carlo quadrature; Asian option; Monte Carlo pricing method; Lévy market models; Mathematical statistics; Matematisk statistik; Mathematical Statistics; matematisk statistik;

    Abstract : In this thesis, we study numerical analysis for random processes and fields. We investigate the behavior of the approximation accuracy for specific linear methods based on a finite number of observations. Furthermore, we propose techniques for optimizing performance of the methods for particular classes of random functions. READ MORE