Sökning: "High-dimensionality"

Visar resultat 11 - 15 av 19 avhandlingar innehållade ordet High-dimensionality.

  1. 11. Statistical assessment of somatic mutations and genomic variability using DNA sequence data

    Författare :Anna Rehammar; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; DNA sequence data; exome sequencing; calling of somatic mutations; metagenomics; hierarchical Bayesian model; genomic variability; calling of somatic mutations;

    Sammanfattning : The development of new DNA sequencing techniques have made it possible to generate high-resolution genomic data at an unprecedented pace. However, the high dimensionality in combination with the substantial levels of technical errors and biological variability make the analysis challenging. LÄS MER

  3. 12. Valid causal inference in high-dimensional and complex settings

    Författare :Niloofar Moosavi; Xavier de Luna; Jenny Häggström; Edward Kennedy; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Causal inference; high dimension; sensitivity analysis; variable selection; convolutional neural network; semiparametric efficiency bound; Statistics; statistik;

    Sammanfattning : The objective of this thesis is to consider some challenges that arise when conducting causal inference based on observational data. High dimensionality can occur when it is necessary to adjust for many covariates, and flexible models must be used to meet convergence assumptions. The latter may require the use of a novel machine learning estimator. LÄS MER

  4. 13. Sparse Modeling Heuristics for Parameter Estimation - Applications in Statistical Signal Processing

    Författare :Stefan Ingi Adalbjörnsson; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; parameter estimation; sparse models; convex optimization; fundamental frequency; inharmonicity; audio localization; symbolic periodicity; alternating directions method of multipliers; N-dimensional decaying sinusoids.;

    Sammanfattning : This thesis examines sparse statistical modeling on a range of applications in audio modeling, audio localizations, DNA sequencing, and spectroscopy. In the examined cases, the resulting estimation problems are computationally cumbersome, both as one often suffers from a lack of model order knowledge for this form of problems, but also due to the high dimensionality of the parameter spaces, which typically also yield optimization problems with numerous local minima. LÄS MER

  5. 14. Artificial intelligence in weather and climate prediction : Learning atmospheric dynamics

    Författare :Sebastian Scher; Gabriele Messori; Roberto Buizza; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : Weather and climate prediction is dominated by high dimensionality, interactions on many different spatial and temporal scales and chaotic dynamics. This makes many problems in the field quite complex ones, and also state-of-the-art numerical models are - despite their immense computational costs - not sufficient for many applications. LÄS MER

  7. 15. Flow control and reduced-order modelling of transition in shear flows

    Författare :Reza Dadfar; Dan Henningson; Vasssilis Theofilis; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow control; plasma actuator; wing; leading edge; flat plate; wind turbine; optimal controller; model reduction; proper orthogonal decomposition; dynamic mode decomposition.;

    Sammanfattning : In this thesis direct numerical simulation is used to investigate the possibility to delay the transition from a laminar to a turbulent flow in boundary layer flows. Furthermore, modal analysis techniques are used to identify the coherent structures in wind turbine wake. LÄS MER