Search for dissertations about: "lognormal"

Showing result 1 - 5 of 20 swedish dissertations containing the word lognormal.

2. 1. Survey estimation for highly skewed data

   Author : Forough Karlberg; Chris Skinner; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Extreme values; skewed populations; model-based inference; superpopulation; lognormal distribution; statistik; Statistics;

   Abstract : Estimation of the population total of a highly skewed survey variable from a small sample is problematic if straightforward methods are used since (i) when there are no extreme values in the sample, too small estimates will be obtained (ii) if extreme values are sampled, the estimates will become grotesquely large. Traditional methods for outlier treatment will usually compensate for outliers in the sample, thereby avoiding (ii), whereas the small negative bias of (i) will persist. READ MORE

4. 2. Scattering of seismic waves in random velocity models : Finite difference simulation

   Author : Lena Frenje; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

   Abstract : The small-scale heterogeneities within the Earth's crust and the effect these heterogeneities have on seismic waves have gained increasing interest in the last 15 years. One approach to study seismic wave scattering is through numerical simulations in random media. READ MORE

5. 3. On the efficiency of the Bayesian bootstrap

   Author : Raul Cano; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Poisson-fördelning;

   Abstract : The efficiency of the Bayesian bootstrap is treated for large and small samples from infinite and finite populations. The Bayesian bootstrap is compared with nonparametric and parametric Bayesian methods in the infinite case, for large samples and considering the mean and truncation functionals. READ MORE

6. 4. Aspects of quarks in exotic matter

   Author : Daniel Enström; Luleå tekniska universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Fysik; Fysik;

   Abstract : In this licentiate thesis, two different aspects of particle physics have been studied. The results are presented in four papers. In papers I and II, a model for a joint origin of gamma-ray bursts and dark matter is presented. The common denominator is the deconfined state of quarks, the Quark-Gluon Plasma (QGP). READ MORE

7. 5. Quantification of gene expression in single cells

   Author : Martin Bengtsson; Islet cell physiology; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Medicin människa och djur ; Medicine human and vertebrates ; Biomedical sciences; Biomedicinska vetenskaper; quantitative gene expression analysis; single cell PCR; islets of Langerhans;

   Abstract : Studies of apparently homogeneous cell populations and single cells often give highly divergent results. Cells exhibit varying responsiveness to stimuli and gene expression and they are in many aspects stochastic and unpredictable. We have developed a method to measure gene expression quantitatively in individual cells with real-time RT-PCR. READ MORE