Sökning: "principal components PC"

Hittade 4 avhandlingar innehållade orden principal components PC.

  1. 1. Likelihood-Based Panel Unit Root Tests for Factor Models

    Författare :Xingwu Zhou; Johan Lyhagen; Joakim Westerlund; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Panel unit root; Exact factor model; Dynamic factor model; Maximum likelihood; Principal components; Lagrange multiplier;

    Sammanfattning : The thesis consists of four papers that address likelihood-based unit root tests for panel data with cross-sectional dependence arising from common factors.In the first three papers, we derive Lagrange multiplier (LM)-type tests for common and idiosyncratic unit roots in the exact factor models based on the likelihood function of the differenced data. LÄS MER

  3. 2. A multivariate approach to QSAR

    Författare :Sven Hellberg; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; QSAR; beta-adrenergic agents; haloalkanes; halogenated anesthetics; peptides; fractional factorial design; multivariate data analysis; principal components PC ; partial least squares PLS ;

    Sammanfattning : Quantitative structure-activity relationships (OSAR) constitute empirical analogy models connecting chemical structure and biological activity. The analogy approach to QSAR assume that the factors important in the biological system also are contained in chemical model systems.The development of a QSAR can be divided into subproblems:1. LÄS MER

  4. 3. Theoretical description of Ti and Ti alloys from first principles

    Författare :Natalia Skripnyak; Igor Abrikosov; Iryna Yakimenko; Sergey Simak; Zi-Kui Liu; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; T; Ti alloys; DFT; molecular dynamics; thermodynamic properties; elastic properties;

    Sammanfattning : Modern world is known for many advanced technologies and solutions to complex problems. Technical progress runs at high speed. In order to most effectively use materials, given to us by Nature, it is important to know their properties. To do laboratory experiments is often too expensive and time consuming. LÄS MER

  5. 4. Mostly Panel Econometrics : Essays on Asymptotic Analysis and Enhanced Inference

    Författare :Ovidijus Stauskas; Joakim Westerlund; Ignace De Vos; Milda Norkute; Nationalekonomiska institutionen; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Econometrics; Panel Data; Factor Models; Bootstrap; Forecasting; Non-Stationary Data; Common Correlated Effects; CCE;

    Sammanfattning : This thesis consists of five chapters which focus on panel data theory. Four of them analyze explicit panel data models and one chapter deals with time series forecasting model, where external panel data help us estimate unobserved explanatory variables. LÄS MER