Sökning: "weighted least squares"

Visar resultat 1 - 5 av 40 avhandlingar innehållade orden weighted least squares.

  1. 1. Algorithms for the Weighted Orthogonal Procrustes Problem and other Least Squares Problems

    Författare :Thomas Viklands; Per-Åke Wedin; Lars Eldén; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Procrustes; weighted; orthogonal; algorithms; global optimization.; Numerical analysis; Numerisk analys;

    Sammanfattning : In this thesis, we present algorithms for local and global minimization of some Procrustes type problems. Typically, these problems are about rotating and scaling a known set of data to fit another set with applications related to determination of rigid body movements, factor analysis and multidimensional scaling. LÄS MER

  3. 2. System Identification with Multi-Step Least-Squares Methods

    Författare :Miguel Galrinho; Håkan Hjalmarsson; Manfred Deistler; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The purpose of system identification is to build mathematical models for dynam-ical systems from experimental data. With the current increase in complexity of engineering systems, an important challenge is to develop accurate and computa-tionally simple algorithms, which can be applied in a large variety of settings. LÄS MER

  4. 3. Least Squares Methods for System Identification of Structured Models

    Författare :Miguel Galrinho; Håkan Hjalmarsson; Lennart Ljung; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The purpose of system identification is to build mathematical models for dynamical systems from experimental data. With the current increase in complexity of engineering systems, an important challenge is to develop accurate and computationally efficient algorithms. LÄS MER

  5. 4. Some Aspects on Confirmatory Factor Analysis of Ordinal Variables and Generating Non-normal Data

    Författare :Hao Luo; Fan Yang-Wallentin; Johan Lyhagen; Karl Jöreskog; Marie Wiberg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; confirmatory factor analysis; ordinal variables; maximum likelihood; weighted least squares; polychoric correlation; non-normal data; Fleishman s method; Monte Carlo simulation; Statistics; Statistik; Statistics; Statistik;

    Sammanfattning : This thesis, which consists of five papers, is concerned with various aspects of confirmatory factor analysis (CFA) of ordinal variables and the generation of non-normal data. The first paper studies the performances of different estimation methods used in CFA when ordinal data are encountered. LÄS MER

  7. 5. Adaptive finite element methods for parameter estimation problems in partial differential equations

    Författare :Tao Feng; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; parameter estimation; ¯nite element approximation; adaptive ¯nite element methods; a posteriori error estimates; least squares.; MATHEMATICS; MATEMATIK;

    Sammanfattning : Physical and chemical phenomena are often described by a system of partial di®erential equations. These equations usually involve unknown parameters, which cannot be measured directly but which can be adjusted to make the model predictions match the observed data. LÄS MER