Sökning: "covariances."

Visar resultat 1 - 5 av 27 avhandlingar innehållade ordet covariances..

1. 1. Approaching well-founded comprehensive nuclear data uncertainties : Fitting imperfect models to imperfect data

   Författare :Petter Helgesson; Henrik Sjöstrand; Helmut Leeb; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Evaluated nuclear data; uncertainty propagation; uncertainty quantification; model defects; Gaussian processes; TALYS; TENDL; covariances.; Fysik med inriktning mot tillämpad kärnfysik; Physics with specialization in Applied Nuclear Physics;

   Sammanfattning : Nuclear physics has a wide range of applications; e.g., low-carbon energy production, medical treatments, and non-proliferation of nuclear weapons. Nuclear data (ND) constitute necessary input to computations needed within all these applications. LÄS MER

3. 2. The Diversity and Unity of Reactor Noise Theory

   Författare :Zhifeng Kuang; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; neutron fluctuations; master equations; correlations; stochastic processes; the Langevin technique; power spectra; reactor noise; covariances;

   Sammanfattning : The study of reactor noise theory concerns questions about cause and effect relationships, and the utilisation of random noise in nuclear reactor systems. The diversity of reactor noise theory arises from the variety of noise sources, the various mathematical treatments applied and the various practical purposes. LÄS MER

4. 3. Models and Methods for Random Fields in Spatial Statistics with Computational Efficiency from Markov Properties

   Författare :David Bolin; Matematisk statistik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; random fields; Gaussian Markov random fields; Matérn covariances; stochastic partial differential equations; Computational efficiency;

   Sammanfattning : The focus of this work is on the development of new random field models and methods suitable for the analysis of large environmental data sets. A large part is devoted to a number of extensions to the newly proposed Stochastic Partial Differential Equation (SPDE) approach for representing Gaussian fields using Gaussian Markov Random Fields (GMRFs). LÄS MER

5. 4. Some Contributions to Description and Validation of the Extreme Value Distribution

   Författare :MirNabi PirouziFard; Statistiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; weighted least squares estimator.; probability plot; power of tests; extreme value distribution; variances and covariances; goodness-of-fit tests; order statistics; Approximations of means;

   Sammanfattning : This thesis focuses on the validation and description of the Gumbel distribution. Since this is a scale and location parameter distribution, the generalized least squares regression of the order statistics on the expected values can be used, without the necessity of iteration, to obtain the best linear unbiased estimates of the parameters. LÄS MER

7. 5. Genetic variance and covariance components for across population evaluation of Brown Swiss cattle

   Författare :Anne Loberg; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

   Sammanfattning : Dairy cattle breeding is an international business, with trade of animal material across populations. Interbull performs international genetic evaluations of dairy bulls, enabling fair comparisons across populations. LÄS MER