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Learning Trajectories From Human Demonstration Via Time Invariant Dynamical Systems, Paul Gesel

Doctoral Dissertations

Learning from Demonstration (LfD) is a powerful approach that enables users to program robots by simply demonstrating how to perform tasks. Rather than just mimicking the task, the robot should capture key characteristics of the task to adapt and generalize in various situations. Given that there is no explicit objective for each demonstrated task, optimal control methods cannot be directly applied. Two primary paradigms have emerged to overcome the limitation: 1) inverse learning and 2) imitation learning. In this dissertation, I formulate several time-invariant and stable dynamic system-based LfD models that leverage both inverse learning and imitation learning in the …

Exploring The Mechanistic Effects Of Surface Characteristics On Uv254 And Bl405 Disinfection Efficacy, Castine Annastasia Bernardy

Doctoral Dissertations

The COVID-19 pandemic highlighted the need for more robust surface disinfection technologies. Photoinactivation efficacy for microbial pathogens and many surrogates has been well studied for water disinfection. However, there is a limited body of knowledge from research on surface disinfection applications of these technologies. The onset of the global pandemic resulted in a dramatic increase in surface disinfection devices being marketed to consumers, yet regulations for such devices have not been developed. This doctoral research studies the inactivation efficacy of two wavelengths, UV254 and BL405. The objective of this doctoral dissertation was to expand the body of knowledge required to …

Ratiometric Fluorescent Sensors Based On Non-Covalent Crosslinked Molecular Imprinted Polymers, Yuan Chen

Doctoral Dissertations

This thesis describes a series of optical chemosensors based on FRET between fluorophores on the polymer and the substrate. It involved the preparation of the polymer and nanoparticles for the chemosensor, and the sensing behavior based on the preparation methods.A photophysically inert sensor matrix was prepared by a robust and simple emulsion method. Stannic oxide encapsulated silica nanoparticles with diameters between 25 and 70 nm have been prepared by one-pot reverse-phase emulsion methodology. The constituents and core/shell morphology of the nanoparticles were demonstrated by electron microscopic technology, energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). X-ray diffraction (XRD) was …

Telehealth In The Wake Of Covid-19: The Impact Of Telehealth Expansion On Healthcare Access, Utilization, And Outcomes, Deirdre Ann Colburn

Doctoral Dissertations

The COVID-19 pandemic brought unprecedented change to the healthcare industry, including a large and rapid shift to providing care through telehealth technologies. Though the expansion of telehealth services was successful in continuing to provide patients with care while preventing the spread of disease, it is less clear how patient sociodemographic characteristics influenced telehealth use during this time. Similarly, less is known about how or if state-level parity laws influenced rates of individual-level telehealth utilization. To address these areas of research, this dissertation does three things. First, I conducted a systematic review of the literature on demographic disparities in telehealth access, …

Aspects Of Localizing Quantum Information In Diffeomorphism-Invariant Theories, Adam Dukehart

Doctoral Dissertations

Quantum Field Theory (QFT) is often formulated using local operators, i.e., operators defined at points on a fixed background spacetime. However, General Relativity (GR) requires that observables be fully diffeomorphism invariant. This includes invariance not only under passive diffeomorphisms, which change the coordinate system but also active diffeomorphisms, which imply background independence and a dynamical metric. Localizing such systems and observables in quantum gravity has been a long-standing problem. This dissertation makes progress on two facets of this problem. Part I shows that a typical quantum information paradox using local operators cannot be embedded in a self-consistent, low-energy prescription which …

Exploring Protein Function And Stability: Case Studies On Cryoprotection And Thermal Stability Of Antifreeze Proteins, Enzyme Inhibition Of Sars-Cov-2 Main Protease, And B. Subtilis Protein Stability, Katarina Jovic

Doctoral Dissertations

In this work, I have explored basic questions related to protein structure, function, and stability, which are critical for understanding the fundamental mechanisms of biology. The dissertation is divided into four chapters, which are different topics I have worked on. In Chapters 1 and 2, I will discuss my work on two different antifreeze proteins, in Chapter 3 my work on the main protease from SARS-CoV-2 is presented, while Chapter 4 details the characterization of protein stability of four B. subtilis proteins. While the projects are distinct from one another, they all contribute to deciphering the molecular basis of life …

Potential Vorticity Dynamics Driving Variability In Mean Tidal Currents Flowing Through Bounded Estuarine Channels, Katherine Anne Kirk

Doctoral Dissertations

Tidally induced pressure gradients in sea level drive mean estuarine tidal currents that can have horizontal spatial variability across a bounded channel or inlet. Strong cross-channel gradients in along-channel mean velocity set up extremums in the background potential vorticity that can support instabilities of tidal currents flowing through narrow, bounded estuarine channels and tidal inlets. In addition, conservation of potential vorticity including frictional terms, results in intensification of along-channel tidal currents over shallow lateral shelves. In the first part of this dissertation (Chapter 2), the dispersion equation of barotropic instabilities of tidal currents is analytically solved for simple bathymetry defined …

Investigating Posttranslational Modifications Of Hsp90 And The Epichaperome In Embryonic Stem Cells, Seth William Mcnutt

Doctoral Dissertations

Heat shock protein 90 (Hsp90) is a highly conserved and essential molecular chaperone in eukaryotes. Through interactions with various co-chaperones, Hsp90 is able to adapt to meet the specific needs of a structurally and functionally diverse, but specific set of clienteles. The diversity of its clients makes it a key regulator of nearly all cellular processes, and it serves as a central hub for many different signaling networks. One of the major functions of the Hsp90 chaperone machinery is in the modulation of protein homeostasis, a protective function often exploited in cancer cells in order to buffer oncogenic mutations and …

Developing Genetic Resources Within The Chenopodium Genus To Advance Quinoa Breeding And The De Novo Domestication Of C. Berlandieri, Clayton David Ludwig

Doctoral Dissertations

Quinoa (Chenopodium quinoa), an orphan crop native to South America, is tolerant of drought and saline soils and produces a highly nutritious grain. Given these qualities, the demand for this pseudocereal has been steadily increasing, and quinoa breeding programs can now be found throughout the world. I believe the introduction of quinoa-like cultivars developed specifically for Northern New England (NNE) with the region’s climate and disease pressures taken into consideration will benefit local farmers and consumers. Quinoa breeding efforts must consider its allopolyploid (2n = 4x = 36: AABB) genome composition as well as its reticulate ancestry, having descended via …

Engineering Studies Of An Experimental Open Ocean Seaweed Farm Design, Zachary Moscicki

Doctoral Dissertations

An experimental seaweed cultivation system was designed for offshore and exposed locations. Novel features were incorporated to address major barriers to the expansion of seaweed, including limited nearshore and sheltered marine locations and risk of marine animal entanglement. A novel modular mooring geometry was developed to improve stability, reliability, and spatial efficiency to achieve an economical and robust structure viable in high wave energy environments. Stiff composite (e.g. fiberglass) rods were used to replace components typically made of rope, including mooring lines and seaweed growth substrate (cultivation lines), as a means to mitigate risk of marine animal entanglement.

This dissertation …

Towards Improved Genomic Surveillance Of Organisms, Joseph L. Sevigny

Doctoral Dissertations

DNA and RNA sequencing is an indispensable tool for the surveillance and monitoring of organisms. Technological advances and research opportunities over the past several years have transformed and driven my research questions; from understanding the impacts of environmental perturbations on complex benthic communities, to tracking and understanding emerging pathogens like SARS-CoV-2. All of them revolve around the use of DNA sequencing to ask fundamental questions about our understanding genomes and their relationship to phenotype and the environment. The advent of sequencing-based characterization has revolutionized our approach to studying organismal communities on a large scale, offering the ability to analyze vast …

Thoughtful Learning: An Investigation Of The Relationships Between College Students’ Achievement Appraisals And Thinking Patterns During Lecture, Shelby Lynn Smith

Doctoral Dissertations

The current set of studies examined whether two common appraisals that students make during learning (whether they have control over their learning and whether they place value into learning the material) give rise to common types of thoughts students also experience (mind wandering, personal connections, and freely-moving thought). Study One naturistically examined students’ appraisals and thoughts while learning in a real classroom. Study Two attempted to experimentally manipulate students’ appraisals and thus their thoughts in an online learning environment. Overall, results suggest that appraisals do seem to influence the thoughts students report experiencing, although results differ between online and classroom …

Understanding The Role Of Impounded Water Bodies In River Network Nutrient Exports In A Dynamic Landscape, Christopher Thomas Whitney

Doctoral Dissertations

Impounded water bodies are a significant component of aquatic networks and various forms have been studied extensively. However, knowledge gaps exist in the research on human-made dams and their reservoirs as well as beaver ponds as both uniquely affect water quality and nutrient exports in different ways. This study fills those knowledge gaps by investigating fluxes of all forms of dissolved nitrogen from small, human-made reservoirs at seasonal timescales. This study found that small reservoirs have a significant effect on nitrogen concentrations but this effect is seasonal and fluxes transported downstream are highly dependent on discharge. Removal of small dams …

A Global Gene Expression Approach To Exploring Rock Colonization By Blastococcus Saxobsidens, Ryan Patrick Wilmot

Doctoral Dissertations

Introduction: Blastococcus saxobsidens is an endolithic bacterium associated with biodegradation of stone monuments across the Mediterranean basin. Recently, strains of the bacterium have been isolated from high altitude deserts in Chile, volcanic glass in Iceland, and from masonry of several cultural heritage sites across Europe and the Americas. Blastococcus saxobsidens global dispersion has been linked to patterns of wind distributed dust particles. The physiology that this bacterium uses to colonize a wide range of rock types in such distinct locations has not been previously explored however. This project has established that B. saxobsidens colonizes and respires a variety of chemically …

Displaying Phenylalanine Ammonia Lyases On Bacillus Subtilis Spore Surface For The Treatment Of Phenylketonuria Through Oral Administration, Guo Wu

Doctoral Dissertations

Bacillus subtilis spores are formed in response to adverse conditions as a survival mechanism. These spores are in a dormant state and do not require any nutrients. Their DNA is wrapped with self-assembled multilayers of protective proteins. These spores are highly resistant to various harsh conditions. B. subtilis spores serve as a well-characterized model for studying endospore formation and have been developed as a platform system for displaying heterologous proteins of various functions. It has been demonstrated that proteins displayed on the spore surface can enhance their robustness and extend their shelf-life, including enzymes as robust biocatalysts and antigens as …

Investigation Of Robust And Adaptive Control Methods For Systems With Uncertain Equilibrium States, Muhammad Hamad Zaheer

Doctoral Dissertations

Equilibrium states represent the natural resting point of dynamic systems in their state-space and provide vital information for the design of stabilizing feedback controllers for these systems. Stabilizing a system at an equilibrium state is desirable as it requires a zero steady-state control signal, resulting in lower energy consumption by the actuator. Mathematical models of real systems usually contain uncertainties that make it difficult to determine the exact values of these equilibrium states. Therefore, control methods requiring precise knowledge of the equilibrium state are ineffective in controlling systems when uncertainties make determining the exact value of the equilibrium state challenging …

Symmetry, Bifurcations And Transition To Turbulence, Pratik Prashant Aghor

Doctoral Dissertations

This thesis focuses on two wall-bounded shear flows, namely, plane Poiseuille flow, where a fluid is pushed between two infinite parallel plates and radially heated Taylor-Couette flow, where a fluid is sheared between two independently rotating cylinders maintained at different temperatures. An overarching theme of this thesis is understanding and exploiting the interplay between symmetries and dynamics.

Chapter 1 presents an overview of the field of transition to turbulence and introduces the dynamical systems viewpoint of turbulence. In particular, we discuss subcritical transition to turbulence, where flows are observed to be turbulent below critical thresholds predicted by linear stability analysis. …

Resiliency And Sustainability Of Drinking Water Systems Under Long Term And Emergency Contamination, Taler S. Bixler

Doctoral Dissertations

This PhD dissertation is dedicated to the understanding and enhancement of the sustainability of public drinking water systems, addressing both emerging contaminants and emergency contamination events. A key focus is placed on comprehending the tradeoffs encompassing public health, economic, and environmental aspects associated with different actions aimed at improving system resiliency. By providing drinking water authorities with the tools and methodologies to evaluate available options, this research aims to empower decision-makers in their efforts to strengthen their drinking water systems against a myriad of threats.

This dissertation commences by investigating the tradeoffs related to the treatment of PFAS-contaminated water. The …

Conditionally Automated Vehicles As A Safe And Productive Workspace, Nabil Al Nahin Ch

Doctoral Dissertations

Future automated vehicles will allow drivers to reclaim some of their driving time and perform personal or work-related activities while the car is in automated driving mode. However, traditional automotive user interfaces (UIs) are not designed to support such activities. For a vehicle to be considered a safe and productive workspace, we will have to explore how drivers can interact with emerging UIs in a car to engage in complex non-driving related tasks (NDRTs) and safely resume driving when needed. In the second chapter of this thesis, we present a user-elicitation study where we investigate how drivers would want to …

Knowing Me, Knowing You: The Role Of Personal Intelligence In Romantic Relationship Conflict Communication, Victoria Bryan

Doctoral Dissertations

People bring to their relationships a variety of personality traits that guide their interactions with others. However, an individual’s unique set of needs, preferences and skills can make conflict a near-inevitable part of most relationships. Personal intelligence is a promising new construct with implications for how couples communicate during conflict. Named in parallel with spatial, social, and similar intelligences, personal intelligence involves the ability to reason about the personality of oneself and others. People high in personal intelligence show an increased capacity to recognize the motives that guide other’s behavior, which they use to adjust how they approach their interpersonal …

Remembering Interactions With Others: The Role Of Personal Intelligence And Personality, Nikolay Dimitrov

Doctoral Dissertations

One relatively unexplored area in memory and personality research concerns the role that personal intelligence—i.e., a person’s ability to understand and reason about their own and others’ personalities—and personality traits may play in the way people think back to and remember their personal past. The current studies extended prior research by directly examining for the first time the relationship between personal intelligence, personality traits, and memory for specific aspects of the personal past. Across two studies, 391 participants (NStudy 1 = 141; NStudy 2 = 250) of different age groups completed a Qualtrics survey comprised of open-ended narrative prompts and …

Finding Synergy: Improving Biopesticide Efficacy For Disease Control Through Co-Application With The Natural Product Chitosan, Liza M. Degenring

Doctoral Dissertations

Annual crop losses caused by plant diseases are estimated worldwide at 220 billion US dollars. Conventional fungicides are the primary means to control these diseases, however there are growing concerns over human health, effects on non-target species, and environmental contamination. Furthermore, many plant pathogens have developed fungicide resistance due to overexposure to chemicals with single modes of action. There is a worldwide trend to explore alternative tools to reduce the use of synthetic fungicides while continuing to reduce plant disease. Among these control strategies are the use of antagonistic microorganisms (biopesticides) and naturally occurring compounds that have fungicidal activity. Chitosan …

Studies In Computational Plasma Physics, John Donaghy

Doctoral Dissertations

The scope of this work spans computational plasma simulation and modeling using state-of-the-art numerical and machine learning methods. The numerical work discussed involves performance and correctness modeling of two massively scalable heterogenous code bases. A gyrokinetic code used to simulate a plasma subjected to a strong magnetic guiding field and a particle-in-cell code used for simulating high energy density plasmas in a number of scenarios undergoing magnetic reconnection. Both code bases are capable of being distributed to cpu or gpu based compute nodes.

The gyrokinetic code was used to study microinstabilities and turbulence in the edge region of a magnetically …

An Analysis Of Fine-Scale Structure Within Ion Upwelling Processes, Niharika Godbole

Doctoral Dissertations

This dissertation showcases the projects that I have been involved with since I joined the Magnetosphere-Ionosphere Research Laboratory (MIRL) at the University of New Hampshire (UNH) in August 2017, under the guidance of my research advisor, Marc Lessard. Chapters 1, 2, and 3 of this dissertation are intended to provide the science background necessary to discuss the research projects presented in Chapters 4, 5, and 6 respectively.

The system that this dissertation addresses is complex and interconnected. In the most general sense, the Sun interacts with the Earth through the highly conductive, magnetized plasma that it emits, which directly shapes …

Hypergroups From Fusion Subcategories And Their Integral Forms, Alice A. Hempel

Doctoral Dissertations

Fusion categories are generalizations of finite groups and are found in areas of mathematics that involve algebraic structures. They are also found in other fields, such as theoretical physics (quasiparticles) and computer science (quantum computing). Their ubiquitousness in these areas make them useful subjects to study.

As a generalization of finite groups, fusion category theory contains many analogs to the objects and constructions found in group theory. But an analog to an essential object of study in group theory, that of the quotient group, is relatively unexplored. In this work, we introduce quotients of braided fusion categories as certain hypergroups …

Building An Open Source Toolkit For Integrating Multiple Datasets For Seafloor Characterization And Habitat Mapping, Massimo Di Stefano

Doctoral Dissertations

Characterizing and mapping the seafloor and its features requires collecting and analyzing datasets of varied types and scales. Remotely-sensed data can increase our understanding of seafloor processes by providing insight into seabed geomorphology, substrate characteristics, etc., over large areas. Collecting direct observations or physical samples of the seafloor, also known as ground-truth data, holds the key to interpreting and validating remote sensing data. In this thesis, the case is made that by concurrently analyzing some or all of these datasets, knowledge about seafloor processes is gained more efficiently and I develop tools for seafloor habitat mapping.

In Paper I, I …

Robust Behavior Cloning For Multi-Step Sequential Task Learning By Robots, Mostafa Abdallah Mohamed Hussein

Doctoral Dissertations

This research is about learning high-level policies of multi-step sequential (MSS) tasks – such as activities of daily living – from demonstrations in a sample efficient manner. This research does not assume access to a simulator or an expert to provide more demonstrations. Learning a task policy in such a setting using state-of-the-art end-to-end approaches is sample inefficient due to a reliance on deep learning frameworks, which are known to require a large amount of data. Besides that, most imitation learning frameworks in robotics assume that a domain expert’s demonstration always contains a correct way of doing the task. Despite …

Essays On International Trade And The Environment, Ziba Karjoo

Doctoral Dissertations

This research is an empirical and theoretical investigation into the effect of international trade on firms’ environmental performance. In the first chapter, I explore how exports affect energy consumption. One concern about international trade is its impact on the environment: when a firm expands its output, trade increases, and so does pollution. This concern would be mitigated if exporters use "cleaner'' technologies than non-exporters. Using Chilean data, I investigate whether exports drive firms to substitute fuel, a dirty technology, for electricity, a clean technology. While I do not find a significant difference between these uses when controlling for export status, …

Non-Equilibrium Multiphase Particle Morphologies: Synthesis, Functionalization & Modeling, Yung-Chun Lin

Doctoral Dissertations

Waterborne technology highlights the advantage of using water as the dispersed media to replace the need for organic solvents. Emulsion polymerization is one of the most important techniques to produce functional polymer colloids of industrial importance. Besides the choice of monomers in the reaction, composite particle morphology significantly influences the mechanical properties of the materials in the applications of architectural coatings, adhesives, printing inks, and impact resistant plastics. Generally, emulsion polymerization produces spherical particles in the presence of water due to surface tension forces. In seeded emulsion polymerization, composite particles containing two incompatible phases can lead to various anomalous structures …

Affecting Martensitic Transformation And Residual Stress Development Through Stress Superposition And Incremental Forming, Elizabeth Marie Mamros

Doctoral Dissertations

Stress superposition is defined as the incorporation of additional stresses into an existing manufacturing process during a single operation. In this thesis, experiments, simulations, and modeling of stress superposition in sheet metal deformation were investigated. Stress superposition can be used in manufacturing to reduce forming forces, increase material formability, and tailor the final part properties of products according to their intended applications, creating so-called functionally graded materials. Austenitic stainless steels (SS) were the focus due to their susceptibility to strain-induced phase transformation from austenite to martensite based on the stress state applied. In the first chapter, a novel cruciform specimen …