Sökning: "Importance sampling"

Visar resultat 16 - 20 av 254 avhandlingar innehållade orden Importance sampling.

  1. 16. Pointwise and Genomewide Significance Calculations in Gene Mapping through Nonparametric Linkage Analysis: Theory, Algorithms and Applications

    Författare :Lars Ängquist; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; programming; actuarial mathematics; Statistik; cytogenetics; Genetik; cytogenetik; Mathematics; Matematik; Statistics; operations research; Genetics; ROC curves; conditioning loci; optimal score functions; noncentrality parameter; cost adjusted relative efficiency; exponential tilting; importance sampling; Monte Carlo simulation; normal approximation; crossover rate; process maximum; analytical approximation; significance calculations; NPL score; conditional linkage analysis; two-locus linkage analysis; Allele sharing; aktuariematematik; operationsanalys; programmering; gene-gene interaction; composite hypotheses; genetic disease models; classes of score functions; nonparametric linkage analysis;

    Sammanfattning : In linkage analysis or, in a wider sense, gene mapping one searches for disease loci along a genome. This is done by observing so called marker genotypes (alleles) and phenotypes (affecteds/unaffecteds) of a pedigree set, i.e. LÄS MER

  3. 17. Fate and transport of POPs in the aquatic environment : with focus on contaminated sediments

    Författare :Sarah Josefsson; Karin Wiberg; Mats Tysklind; Kjell Leonardsson; Jonas S Gunnarsson; Jussi Kukkonen; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bioturbation; bioirrigation; bioaccumulation; secondary sources; buried contaminants; sediment remediation; active capping; thin-layer capping; Marenzelleria spp.; Baltic Sea; polychlorinated dibenzo-p-dioxins; polychlorinated dibenzofurans; polychlorinated biphenyls; hexachlorobenzene; octachloro¬styrene; polybrominated diphenyl ethers; PCDD Fs; PCBs; HCB; OCS; PBDEs; water sampling; passive sampling; particulate fraction; freely dissolved; apparently dissolved; colloid; organic carbon; activated carbon; lignin; sediment-to-water flux; spring bloom; Environmental chemistry; Miljökemi; Persistent organic compounds; Persistenta organiska föreningar; Environmental Science; miljövetenskap;

    Sammanfattning : Persistent organic pollutants (POPs) are hydrophobic substances that readily sorb to organic matter in particles and colloids instead of being freely dissolved in the water phase. This sorption affects the bio­availability and environmental transport of the POPs. LÄS MER

  4. 18. Large deviations for weighted empirical measures and processes arising in importance sampling

    Författare :Pierre Nyquist; Henrik Hult; Ingemar Kaj; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis consists of two papers related to large deviation results associated with importance sampling algorithms. As the need for efficient computational methods increases, so does the need for theoretical analysis of simulation algorithms. This thesis is mainly concerned with algorithms using importance sampling. LÄS MER

  5. 19. Optimal Subsampling Designs Under Measurement Constraints

    Författare :Henrik Imberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; inverse probability weighting; unequal probability sampling; optimal design; active sampling; M-estimation;

    Sammanfattning : We consider the problem of optimal subsample selection in an experiment setting where observing, or utilising, the full dataset for statistical analysis is practically unfeasible. This may be due to, e.g., computational, economic, or even ethical cost-constraints. LÄS MER

  7. 20. The long-term decline of the grey-sided vole (Clethrionomys rufocanus) in boreal Sweden: importance of focal forest patch and matrix

    Författare :Pernilla Christensen; Birger Hörnfeldt; Rolf A. Ims; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; : Destructive sampling; high quality habitat; focal habitat; landscape; habitat fragmentation; threshold; clear-cut; patch size and quality; long-term time-series; Terrestrial ecology; Terrestisk ekologi;

    Sammanfattning : There has been a long-term decline in number of cyclic vole populations in boreal Sweden since the 1970s. Several hypotheses have been suggested to explain this decline. Commonly for C. glareolus, C. LÄS MER