Sökning: "principal components regression"

Visar resultat 6 - 10 av 27 avhandlingar innehållade orden principal components regression.

1. 6. Applications of common principal components in multivariate and high-dimensional analysis

   Författare :Toni Duras; Thomas Holgersson; Tatjana Pavlenko; Jönköping University; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis consists of four papers, all exploring some aspect of common principal component analysis (CPCA), the generalization of PCA to multiple groups. The basic assumption of the CPC model is that the space spanned by the eigenvectors is identical across several groups, whereas eigenvalues associated with the eigenvectors can vary. LÄS MER

3. 7. Calibration Adjustment for Nonresponse in Sample Surveys

   Författare :Bernardo João Rota; Thomas Laitila; Sune Karlsson; Risto Lehtonen; Örebro universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Auxiliary variables; Calibration; Nonresponse; principal com-ponents; regression estimator; response probability; survey sampling; two-step estimator; variance estimator; weighting; Statistics; Statistik;

   Sammanfattning : In this thesis, we discuss calibration estimation in the presence of nonresponse with a focus on the linear calibration estimator and the propensity calibration estimator, along with the use of different levels of auxiliary information, that is, sample and population levels. This is a fourpapers- based thesis, two of which discuss estimation in two steps. LÄS MER

4. 8. Utilization of Andean grain flours in the development of wheat flour dough

   Författare :Sander Jonathan Pérez Villarroel; Avdelningen för livsmedel och läkemedel; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Wheat; Andean grains; Amaranth; Amaranthus caudatus; Canahua; Chenopodium pallidicaule; Quinoa; Chenopodium quinoa; Dough; Substitution; Ultracentrifugation; Phase separation; Dough composition; Macroscopic separation; Freezable water; Textural properties; Compression; Uniaxial tension; Biaxial tension; Principal component analysis; Partial least square regression; Bread;

   Sammanfattning : Bread dough was studied in relation to three Andean grain flours, quinoa (Chenopodium quinoa), amaranth (Amaranthus caudatus) and canahua (Chenopodium pallidicaule), as partial replacements for wheat flour with the perspectives of dough and breadmaking. This thesis deals with the understanding of both dough as a complex system, consisting of various water-filled polymers, and dough as a viscoelastic material, with different responses to deformations, in order to contribute to possibilities for improvements in dough analysis and development of novel products. LÄS MER

5. 9. Applications of chemometrics in the analysis and characterization of lipids

   Författare :Peter Kaufmann; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Lipids; analysis; Lipider;

   Sammanfattning : The main topics of this thesis are the analysis and characterizationof lipids and applications of chemometrics in this field.The techniques of experimental design, polynomial model building,response surface methods, principal components analysis and partialleast squares regression have been explored and utilized in thedeveopment and optimization of analytical methods. LÄS MER

7. 10. A multivariate approach to the analysis of phytoplankton pigments

   Författare :Ludvig Moberg; Olav Kvalheim; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Växtplankton; Analytical Chemistry; analytisk kemi;

   Sammanfattning : Photosynthetic pigments are routinely determined in investigations of marine and freshwater environments, chlorophyll is used as an estimator of phytoplankton biomass. Photosynthetic pigments are also widely used to characterise phytoplankton taxonomic composition. LÄS MER