Sökning: "Variance estimation"

Visar resultat 6 - 10 av 179 avhandlingar innehållade orden Variance estimation.

  1. 6. Aspects of analysis of small-sample right censored data using generalized Wilcoxon rank tests

    Författare :Marie-Louise Öhman; Hans Nyquist; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Censored generalized Wilcoxon rank test statistics; Variance estimation; Jackknifing; Influence function; Gross error sensitivity; Break-Down point; Sensitivity curve; Location parameter estimation; Product-Limit estimator and Monte-Carlo Simulation; Statistics; computer and systems science; Statistik; data- och systemvetenskap; Statistics; statistik;

    Sammanfattning : The estimated bias and variance of commonly applied and jackknife variance estimators and observed significance level and power of standardised generalized Wilcoxon linear rank sum test statistics and tests, respectively, of Gehan and Prentice are compared in a Monte Carlo simulation study. The variance estimators are the permutational-, the conditional permutational- and the jackknife variance estimators of the test statistic of Gehan, and the asymptotic- and the jackknife variance estimators of the test statistic of Prentice. LÄS MER

  3. 7. Moment Estimation Using Extreme Value Methods

    Författare :Joachim Johansson; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pareto distribution; mean estimation; heavy tailed distributions; telecommunication; m -dependence; superpopulation sampling; peaks over threshold; telecommunication;

    Sammanfattning : The thesis is composed of three papers, all dealing with the application of extreme value methods to the problem of moment estimation for heavy-tailed distributions. In Paper A, an asymptotically normally distributed estimate for the expected value of a positive random variable with infinite variance is introduced. LÄS MER

  4. 8. Novel Statistical Methods in Quantitative Genetics : Modeling Genetic Variance for Quantitative Trait Loci Mapping and Genomic Evaluation

    Författare :Xia Shen; Örjan Carlborg; Lars Rönnegård; William Hill; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; statistical genetics; quantitative trait loci; genome-wide association study; genomic selection; genetic variance; hierarchical generalized linear model; linear mixed model; random effect; heteroscedastic effects model; variance-controlling genes; Complex Systems – Microdata Analysis;

    Sammanfattning : This thesis develops and evaluates statistical methods for different types of genetic analyses, including quantitative trait loci (QTL) analysis, genome-wide association study (GWAS), and genomic evaluation. The main contribution of the thesis is to provide novel insights in modeling genetic variance, especially via random effects models. LÄS MER

  5. 9. Estimation Problems in Array Signal Processing, System Identification, and Radar Imagery

    Författare :Richard Abrahamsson; Peter Stoica; A. Lee Swindlehurst; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Parameter Estimation; Array Signal Processing; STAP; SAR; Ground Penetrating Radar; System Identification; Bilinear Models; Covariance Matrix Estimation; Signal processing; Signalbehandling; Signalbehandling; Signal Processing;

    Sammanfattning : This thesis is concerned with parameter estimation, signal processing, and applications. In the first part, imaging using radar is considered. More specifically, two methods are presented for estimation and removal of ground-surface reflections in ground penetrating radar which otherwise hinder reliable detection of shallowly buried landmines. LÄS MER

  7. 10. Local Polynomial Regression with Application on Lidar Measurements

    Författare :Torgny Lindström; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik; differential equations; Funktioner; differentialekvationer; variance-function estimation.; spatial dependence; nonparametric; local polynomial regression; local bandwidth selection; lidar; heteroscedasticity; Bivariate estimation; differential absorption; Functions;

    Sammanfattning : This thesis deals with the problem of estimating a function or one of its derivatives from a set of measurements, mainly of a bivariate or spatial nature which is so common in environmental applications. In this work particular attention has been on the lidar (light detection and ranging) application which is a versatile technique for measurement of among other things atmospheric trace gases. LÄS MER