Sökning: "stratified sampling"

Visar resultat 1 - 5 av 32 avhandlingar innehållade orden stratified sampling.

1. 1. 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

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

   Författare :Anders Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Particulate Mass; SGDI; Particulate Number; Direct-Injected; GDI; Particulate Sampling; Spray-Guided; Particulates; Stratified Charge; Gasoline; DI;

   Sammanfattning : 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. LÄS MER

4. 3. Estimating Probability Distribution by doing Computer Experiments

   Författare :Gunnar Kjell; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; computer simulations; seismic verification; response spectrum prediction; stratified sampling; latin hypercube sampling; variance reduction; variance estimation; seismic verification;

   Sammanfattning : 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. LÄS MER

5. 4. Knowledge predication : A semantic typology

   Författare :Anna Sjöberg; Bernhard Wälchli; Maria Koptjevskaja-Tamm; Volker Gast; Stockholms universitet; []
   Nyckelord :HUMANIORA; HUMANITIES; semantic typology; constructional typology; semantic maps; knowledge; epistemology; parallel texts; language sampling; token-based typology; cognitive semantics; Linguistics; lingvistik;

   Sammanfattning : The present thesis is an investigation of the cross-linguistic expression of knowledge predication (‘He knows that it’s raining’, ‘she knows the boy’ etc.) Knowledge predication is investigated in parallel texts—specifically New Testament translations—in a genealogically and areally stratified variety sample of 83 languages. LÄS MER

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

   Författare :Susanne Strömdahl; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :HIV prevention;

   Sammanfattning : 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. LÄS MER