COMING SOON! PQDT Open is getting a new home!

ProQuest Open Access Dissertations & Theses will remain freely available as part of a new and enhanced search experience at

Questions? Please refer to this FAQ.

Dissertation/Thesis Abstract

On Hidden Structures in Contaminated Symbolic Data
by Pearson, Antony, Ph.D., University of Colorado at Boulder, 2020, 86; 27835343
Abstract (Summary)

Data taking values on discrete sample spaces are the embodiment of modern biological research. ``Omics'' experiments produce millions to billions of symbolic outcomes in the form of reads (i.e., DNA sequences of a few dozen to a few hundred nucleotides). Unfortunately, these intrinsically non-numerical datasets are often highly contaminated, and the possible sources of contamination are usually poorly characterized. The latter contrasts with continuous datasets, where it is often well-justified to assume that the distribution of contaminating samples is Gaussian.

To overcome these hurdles, we introduce the new notion of ``latent weight,'' which measures the largest expected fraction of samples from a contaminated probabilistic source that conforms to a model in a well-structured class of desired models.

We examine various properties of latent weights in general and then specialize the discussion to the mathematical and statistical properties of latent weights of several specially-structured classes of interest. These include the exchangeable distributions, models with independent marginals, as well as models with independent and identically distributed (i.i.d.) marginals. As proof of concept, we use latent weights to analyze DNA methylation data and probabilistic graphical models of infection.

Indexing (document details)
Advisor: Lladser, Manuel E
Commitee: Corcoran, Jem, Dukic, Vanja, Kleiber, William, Larremore, Daniel
School: University of Colorado at Boulder
Department: Applied Mathematics
School Location: United States -- Colorado
Source: DAI 81/11(E), Dissertation Abstracts International
Subjects: Mathematics, Biostatistics, Statistics
Keywords: Contamination, DNA methylation, Exchangeability, Independence, Mixture models, Symbolic data
Publication Number: 27835343
ISBN: 9798645451783
Copyright © 2021 ProQuest LLC. All rights reserved. Terms and Conditions Privacy Policy Cookie Policy