Sökning: "univariate analysis"

Visar resultat 1 - 5 av 140 avhandlingar innehållade orden univariate analysis.

1. 1. Multi-platform metabolomics assays to study the responsiveness of the human plasma and lung lavage metabolome

   Författare :Masoumeh Karimpour; Malin Nording L.; Magnus Åberg; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; LC MS; GC MS; NMR; metabolomics; metabolite; exposure; postprandial; plasma; lung lavage; BW; BW; data analysis; univariate analysis; multivariate analysis;

   Sammanfattning : Metabolomics as a field has been used to track changes and perturbations in the human body by investigating metabolite profiles indicating the change of metabolite levels over time and in response to different challenges. In this thesis work, the main focus was on applying multiplatform-metabolomics to study the human metabolome following exposure to perturbations, such as diet (in the form of a challenge meal) and exhaust emissions (air pollution exposure in a controlled setting). LÄS MER

3. 2. Decoding the complex brain : multivariate and multimodal analyses of neuroimaging data

   Författare :Alireza Salami; Lars Nyberg; Cheryl Grady; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; multivariate analysis; univariate analysis; multimodal imaging; episodic memory; aging; functional magnetic resonance imaging; diffusion tensor imaging; biology; biologi; Psychology; psykologi; datoriserad bildanalys; Computerized Image Analysis;

   Sammanfattning : Functional brain images are extraordinarily rich data sets that reveal distributed brain networks engaged in a wide variety of cognitive operations. It is a substantial challenge both to create models of cognition that mimic behavior and underlying cognitive processes and to choose a suitable analytic method to identify underlying brain networks. LÄS MER

4. 3. Extreme points of the Vandermonde determinant in numerical approximation, random matrix theory and financial mathematics

   Författare :Asaph Keikara Muhumuza; Sergei Silvestrov; Anatoliy Malyarenko; Karl Lundengård; Milica Rancic; Olga Liivapuu; Mälardalens högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Mathematics Applied Mathematics; matematik tillämpad matematik;

   Sammanfattning : This thesis discusses the extreme points of the Vandermonde determinant on various surfaces, their applications in numerical approximation, random matrix theory and financial mathematics. Some mathematical models that employ these extreme points such as curve fitting, data smoothing, experimental design, electrostatics, risk control in finance and method for finding the extreme points on certain surfaces are demonstrated. LÄS MER

5. 4. Processing and analysis of NMR data : Impurity determination and metabolic profiling

   Författare :Jenny Forshed; Sven P. Jacobsson; Jules L. Griffin; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantitative nuclear magnetic resonance spectrometry; qNMR; multivariate analysis; peak alignment; data fusion; Analytical chemistry; Analytisk kemi;

   Sammanfattning : This thesis describes the use of nuclear magnetic resonance (NMR) spectrometry as an analytical tool. The theory of NMR spectroscopy in general and quantitative NMR spectrometry (qNMR) in particular is described and the instrumental properties and parameter setups for qNMR measurements are discussed. LÄS MER

7. 5. Uncertainty intervals and sensitivity analysis for missing data

   Författare :Minna Genbäck; Xavier de Luna; Elena Stanghellini; Arvid Sjölander; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; missing data; missing not at random; non-ignorable; set identification; uncertainty intervals; sensitivity analysis; self reported health; average causal effect; average causal effect on the treated; mixed-effects models; Statistics; statistik;

   Sammanfattning : In this thesis we develop methods for dealing with missing data in a univariate response variable when estimating regression parameters. Missing outcome data is a problem in a number of applications, one of which is follow-up studies. LÄS MER