Sökning: "Poisson ratio"

Visar resultat 1 - 5 av 28 avhandlingar innehållade orden Poisson ratio.

1. 1. On unequal probability sampling designs

   Författare :Anton Grafström; Lennart Bondesson; Sara De Luna; Imbi Traat; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; conditional Poisson sampling; correlated Poisson sampling; entropy; extended Sampford sampling; Horvitz-Thompson estimator; inclusion probabilities; list-sequential sampling; non-rejective implementation; Pareto sampling; Poisson sampling; probability functions; ratio estimator; real-time sampling; repeated Poisson sampling; Sampford sampling; sampling designs; splitting method; unequal probability sampling; Mathematical statistics; Matematisk statistik; Mathematical Statistics; matematisk statistik;

   Sammanfattning : The main objective in sampling is to select a sample from a population in order to estimate some unknown population parameter, usually a total or a mean of some interesting variable. When the units in the population do not have the same probability of being included in a sample, it is called unequal probability sampling. LÄS MER

3. 2. Foam, Fire and Free Volume - Chemical and Physical Aspects of Porous Polymers

   Författare :Anna Andersson; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Poisson ratio; vibration damping; acoustic impedance; cell morphology; hyperbranched polymer; Polymer foams; free volume; positron annihilation; supercritical fluid.;

   Sammanfattning : Automotive seating has been under continous development since it was described for the first time in 1885. At that time one could read about a “padded leather bench seat sitting on springs mounted directly to the frame of a horse-less carriage”. LÄS MER

4. 3. Epidemiological aspects of musculoskeletal pain in the upper body. Analyzing common and recurrent binary outcomes

   Författare :Anna Grimby-Ekman; Göteborgs universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; musculoskeletal; pain; neck; repeated measurements; logistic model; odds ratio OR ; risk ratio RR ; risk difference RD ; biological interaction;

   Sammanfattning : The overall aim of this thesis is to gain epidemiological knowledge about musculoskeletal pain in the upper body in light physical work, in relation to gender, psychosocial factors, and computer use; and to compare different methods for analyzing common and recurrent binary outcomes. Two study groups were investigated using questionnaire data: (a) computer users in the Swedish workforce and (b) a cohort of university students. LÄS MER

5. 4. Strategies for assessing health risks from two occupational cohorts within the domain of northern Sweden

   Författare :Ove Björ; Tohr Nilsson; Håkan Jonsson; Lena Damber; Per Gustavsson; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Cohort; mortality; incidence; risk; rate; cancer; cerebrovascular diseases; exposure; occupational; mining; industry; worker; Poisson regression; Cox regression; SMR; causal inference; G-estimation; Occupational and Environmental Medicine; arbets- och miljömedicin; epidemiologi; Epidemiology;

   Sammanfattning : Background: Studies based on a cohort design requires access to both subject-specific and period-specific information. In order to conduct an occupational cohort study, access to exposure information and the possibility and permission to link information on outcomes from other registers are generally necessary. LÄS MER

7. 5. Contributions to High–Dimensional Analysis under Kolmogorov Condition

   Författare :Jolanta Maria Pielaszkiewicz; Dietrich von Rosen; Martin Singul; Thomas Holgersson; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eigenvalue distribution; free moments; free Poisson law; Marchenko-Pastur law; random matrices; spectral distribution; Wishart matrix; Mathematics; Matematik;

   Sammanfattning : This thesis is about high–dimensional problems considered under the so{called Kolmogorov condition. Hence, we consider research questions related to random matrices with p rows (corresponding to the parameters) and n columns (corresponding to the sample size), where p > n, assuming that the ratio  converges when the number of parameters and the sample size increase. LÄS MER