Sökning: "Bias Correction"

Visar resultat 16 - 20 av 54 avhandlingar innehållade orden Bias Correction.

  1. 16. Multivariate Aspects of Phylogenetic Comparative Methods

    Författare :Krzysztof Bartoszek; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; General Linear Model; Ornstein-Uhlenbeck process; Multivariate phylogenetic comparative method; Evolutionary model; Adaptation; Optimality; Measurement error; Regression; Adaptation; Major-axis regression; Reduced major-axis regression; Structural equation; Allometry; Phylogenetic inertia; Allometry;

    Sammanfattning : his thesis concerns multivariate phylogenetic comparative methods. We investigate two aspects of them. The first is the bias caused by measurement error in regression studies of comparative data. We calculate the formula for the bias and show how to correct for it. LÄS MER

  3. 17. Statistical Modeling of Diffusion Processes with Financial Applications

    Författare :Erik Lindström; Finansiell matematik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; actuarial mathematics; Statistik; operations research; programming; Option pricing; Model validation; Recursive estimation; Diffusion processes; Maximum Likelihood Estimation; operationsanalys; programmering; aktuariematematik; Statistics;

    Sammanfattning : This thesis consists of five papers (Paper A-E) on statistical modeling of diffusion processes. Two papers (Paper A & D) consider Maximum Likelihood estimators for non-linear diffusion processes. LÄS MER

  4. 18. Analyses and Application of Ambient Seismic Noise in Sweden : Source, Interferometry, Tomography

    Författare :Hamzeh Sadeghisorkhani; Ólafur Gudmundsson; Ari Tryggvason; Roland Roberts; Frederik Tilmann; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Seismic interferometry; Ambient noise; Surface wave; Wave propagation; Inverse theory; Sweden; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

    Sammanfattning : Ambient seismic noise from generation to its application for determination of sub-surface velocity structures is analyzed using continuous data recordings from the Swedish National Seismic Network (SNSN). The fundamental aim of the thesis is to investigate the applicability of precise velocity measurements from ambient noise data. LÄS MER

  5. 19. Measurement Variability Related to Insulin Secretion and Sensitivity : Assessment and Implications in Epidemiological Studies

    Författare :Lars Berglund; Björn Zethelius; Johan Bring; Uppsala universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Geriatrics and medical gerontology; Geriatrik och medicinsk gerontologi; Geriatrics; Geriatrik;

    Sammanfattning : There is a growing interest in random measurement variability of biological variables. In regression models, such variability of the predictors yields biased estimators of coefficients (regression dilution bias). LÄS MER

  7. 20. Effects of Small-Scale Ionospheric Irregularities on GNSS Radio Occultation Signals : Evaluations Using Multiple Phase Screen Simulator

    Författare :Vinícius Ludwig Barbosa; Mats Pettersson; Viet Thuy Vu; Stig Syndergaard; Blekinge Tekniska Högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; GNSS Radio Occultation GNSS-RO ; Ionosphere; Scintillation;

    Sammanfattning : Radio Occultation (RO) is a remote sensing technique which uses Global Navigation Satellite System (GNSS) signals tracked by a Low-Earth Orbit (LEO) satellite to sound the earth's atmosphere both in low (troposphere, stratosphere) and high (ionosphere) altitudes. GNSS-RO provides global coverage and SI traceable measurements of atmospheric data with high-vertical resolution. LÄS MER