Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network™

Open Access. Powered by Scholars. Published by Universities.®

PDF

University of Massachusetts Amherst

2017

Discipline
Keyword
Publication
Publication Type

Articles 31 - 60 of 990

Full-Text Articles in Entire DC Network

Microbial Competition In Bioelectrochemical Systems, Varun Srinivasan Nov 2017

Microbial Competition In Bioelectrochemical Systems, Varun Srinivasan

Doctoral Dissertations

Bioelectrochemical systems(BESs)/ microbial fuel fells (MFCs) are a well-studied potential technology for bioremediation and decentralized wastewater treatment. However, progress has been somewhat stalled at the bench-scale. In well controlled experiments electron recovery is high. In natural environments, wastewaters are complex and anode-respiring bacteria can be outcompeted in the presence of competing microorganisms, leading to a loss in electron-recovery and power production. Furthermore, the cathode of the MFC plays a vital role in providing flexibility for treatment options but is an understudied part of MFCs. Modelling Intracellular Competition in a Denitrifying Biocathode: One potential MFC configuration uses an organic-oxidizing anode biofilm …

Go to article

Three Essays On The Theory Of Environmental Regulation: Hybrid Price And Quantity Policies And Regulation In The Presence Of Co-Pollutants, Insung Son Nov 2017

Three Essays On The Theory Of Environmental Regulation: Hybrid Price And Quantity Policies And Regulation In The Presence Of Co-Pollutants, Insung Son

Doctoral Dissertations

This dissertation contains three original essays in the economic theory of environmental regulation. The main motivations for this work are two problems: the design of greenhouse gas (GHG) policies when emissions of these gases interact with so-called co-pollutants and the design of hybrid price and quantity policies to deal with the uncertainty in the benefits and costs of controlling GHG emissions. Abstract Concerns about how best to control GHGs have generated intense interest in the co-benefits and adverse side-effects of climate policies. Efforts to reduce CO2 emissions can reduce emissions of flow pollutants that are emitted along with CO …

Go to article

When Errors Aren't: How Comprehenders Selectively Violate Binding Theory, Shayne Sloggett Nov 2017

When Errors Aren't: How Comprehenders Selectively Violate Binding Theory, Shayne Sloggett

Doctoral Dissertations

It has been claimed that comprehenders use the Binding Theory (Chomsky, 1986) to restrict the search for a reflexive’s antecedent in early stages of comprehension (Dillon, Mishler, Sloggett, & Phillips, 2013; Sturt, 2003; Nicol & Swinney, 1989) However, recent findings challenge this view, demonstrating that comprehenders occasionally access antecedents on the basis of their match with a reflexive’s morphosyntactic features (Chen, Jäger, & Vasishth, 2012; Patil, Lewis, & Vasishth, 2016, Parker, & Phillips, 2017). In this dissertation, I investigate the source of this ’grammatical fallibility’ in the real-time application of Principle A of the Binding Theory. Specifically, I ask whether …

Go to article

Game Theory For Security Investments In Cyber And Supply Chain Networks, Shivani Shukla Nov 2017

Game Theory For Security Investments In Cyber And Supply Chain Networks, Shivani Shukla

Doctoral Dissertations

In a constantly and intricately connected world that is going digital, cybersecurity is imperative to not just the success but also the survival of a business. The ubiquitous digital transformation is fueled by a convulsive growth of devices and data that are leading important innovations in the domain of cyber-physical systems. However, this growth has also enabled internal and external threats to skyrocket, depicting the inherent dichotomy. With an evolving threat landscape, a perpetrator has to be successful once, while the defenders have to continually succeed in fending-off attacks to protect critical infrastructure and digital assets. Businesses are facing a …

Go to article

Computational Studies Of Structure–Function Relationships Of Supported And Unsupported Metal Nanoclusters, Hongbo Shi Nov 2017

Computational Studies Of Structure–Function Relationships Of Supported And Unsupported Metal Nanoclusters, Hongbo Shi

Doctoral Dissertations

Fuel cells have been demonstrated to be promising power generation devices to address the current global energy and environmental challenges. One of the many barriers to commercialization is the cost of precious catalysts needed to achieve sufficient power output. Platinum-based materials play an important role as electrocatalysts in energy conversion technologies. In order to improve catalytic efficiency and facilitate rational design and development of new catalysts, structure–function relationships that underpin catalytic activity must be understood at a fundamental level. First, we present a systematic analysis of CO adsorption on Pt nanoclusters in the 0.2-1.5 nm size range with the aim …

Go to article

Preferential Early Attribution In Segmental Parsing, Amanda Rysling Nov 2017

Preferential Early Attribution In Segmental Parsing, Amanda Rysling

Doctoral Dissertations

This dissertation investigates parsing in segmental perception, or the process by which listeners map the continuous acoustic signal that reaches their ears to the linguistic representations over which phonology operates. It addresses questions of when listeners decide that they have heard acoustic evidence about the identity of one speech sound, versus evidence about the identity of a following sound, and when this linguistic knowledge is applied relative to when it is received during the course of on-line perception and processing. The central argument advanced here is that the beginnings of answers to these questions require the recognition of a domain-general …

Go to article

Modeling Performance, Cost, Delivery, And Trip Distribution Of Demand Responsive Transit Systems With Zoning, Mahour Rahimi Nov 2017

Modeling Performance, Cost, Delivery, And Trip Distribution Of Demand Responsive Transit Systems With Zoning, Mahour Rahimi

Doctoral Dissertations

Demand responsive transit (DRT) services are expensive to operate, so it is crucial to understand the factors that drive the agency costs and be able to investigate and predict the effect of possible changes in specific operating parameters as well as demand and service coverage areas on total costs. In this research, we adopt the concept of the analytical model proposed by Daganzo (1978) to present continuum approximation (CA) models that can estimate important service related factors. As the first step, we propose three analytical models to approximate the operation related variables of DRT services; Fleet Size, Vehicle Hours Traveled …

Go to article

Theory And Practice Of Supply Chain Synchronization, Michael Prokle Nov 2017

Theory And Practice Of Supply Chain Synchronization, Michael Prokle

Doctoral Dissertations

In this dissertation, we develop strategies to synchronize component procurement in assemble-to-order (ATO) production and overhaul operations. We focus on the high-tech and mass customization industries which are not only considered to be very important to create or keep U.S. manufacturing jobs, but also suffer most from component inventory burden. In the second chapter, we address the deterministic joint replenishment inventory problem with batch size constraints (JRPB). We characterize system regeneration points, derive a closed-form expression of the average product inventory, and formulate the problem of finding the optimal joint reorder interval to minimize inventory and ordering costs per unit …

Go to article

Movement And The Semantic Type Of Traces, Ethan Poole Nov 2017

Movement And The Semantic Type Of Traces, Ethan Poole

Doctoral Dissertations

This dissertation argues that there are only two possible semantic representations of movement: (i) a bound variable, i.e. trace, ranging over an individual semantic type, such as entities and degrees, or (ii) reconstruction back into the launching site of movement. Even though natural language has expressions over higher types, these expressions cannot be represented as traces, which only range over individual types. I call this constraint the Trace Interpretation Constraint. The novel empirical motivation for this constraint comes from a detailed investigation of movement targeting DPs that denote properties, a kind of higher-type expression. I observe that such movement obligatorily …

Go to article

Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson Nov 2017

Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson

Doctoral Dissertations

The immense diversity of life on Earth has been attributed to the partitioning of available resources into ecological niches, but it is not obvious what determines the niche size of each species. For example, most plant-feeding insects consume only one or a few closely-related host-plant species despite the advantages of having a broader diet. Many researchers have therefore suggested that the evolution of broad diets in plant-feeding insects must be constrained by genetic trade-offs between adaptations to alternative host-plants. Despite its intuitive feel, however, little empirical evidence in support of the trade-off hypothesis has emerged from decades of experimental studies …

Go to article

Applications And Extensions Of Counterpart Theory, Bridgette Peterson Nov 2017

Applications And Extensions Of Counterpart Theory, Bridgette Peterson

Doctoral Dissertations

An exploration of the details of counterpart theory, and some applications of the view. In Chapter 1, I set out the view and clarify the most important features: that the counterpart relation is a context dependent similarity relation, and that individuals are world-bound entities. I then set out what I take to be the most promising methods of filling in important details. Chapter 2 is a discussion of an alternative view, lump theory. I attempt to distinguish lump theory from counterpart theory, and argue that several attempt to do so fail. Chapter 3 is an attempt to apply counterpart theory …

Go to article

Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel Nov 2017

Analyses Of Densely Crosslinked Phenolic Systems Using Low Field Nmr, Jigneshkumar Patel

Doctoral Dissertations

A uniform dispersion of reactants is necessary to achieve a complete reaction involving multi-components, especially for the crosslinking of rigid high-performance materials. In these reactions, miscibility is crucial for curing efficiency. This miscibility is typically enhanced by adding a third component, a plasticizer. For the reaction of the highly crystalline crosslinking agent hexamethylenetetramine (HMTA) with a strongly hydrogen-bonded phenol formaldehyde resin, furfural has been traditionally used as the plasticizer. However, the reason for its effectiveness is not clear. In this doctoral thesis work, miscibility and crosslinking efficiency of plasticizers in phenolic curing reactions are studied by thermal analysis and spectroscopic …

Go to article

Dialogue And "Dialect": Character Speech In American Fiction, Carly Overfelt Nov 2017

Dialogue And "Dialect": Character Speech In American Fiction, Carly Overfelt

Doctoral Dissertations

This dissertation investigates the linguistic construction of race and place in turn-of-the-century American novels and short stories. Literary analyses of character speech continue to reinforce the old dichotomy of Standard versus nonstandard/dialectal English. I challenge the ideology of Standard English in my readings of works by Mark Twain, Charles Chesnutt, Sarah Orne Jewett, and little-known Cherokee author, Ora V. Eddleman Reed, among others. I argue that these texts create their own standards that interact with (and sometimes resist) the language ideology of their time. By analyzing all variation, rather than only what has been traditionally viewed as “dialect,” I reveal …

Go to article

Knowledge Representation And Reasoning With Deep Neural Networks, Arvind Ramanathan Neelakantan Nov 2017

Knowledge Representation And Reasoning With Deep Neural Networks, Arvind Ramanathan Neelakantan

Doctoral Dissertations

Knowledge representation and reasoning is one of the central challenges of artificial intelligence, and has important implications in many fields including natural language understanding and robotics. Representing knowledge with symbols, and reasoning via search and logic has been the dominant paradigm for many decades. In this work, we use deep neural networks to learn to both represent symbols and perform reasoning end-to-end from data. By learning powerful non-linear models, our approach generalizes to massive amounts of knowledge and works well with messy real-world data using minimal human effort. First, we show that recurrent neural networks with an attention mechanism achieve …

Go to article

Novel Buildings: Architectural And Narrative Form In Victorian Fiction, Ashley R. Nadeau Nov 2017

Novel Buildings: Architectural And Narrative Form In Victorian Fiction, Ashley R. Nadeau

Doctoral Dissertations

This dissertation, “Novel Buildings: Architectural and Narrative Form in Victorian Fiction,” offers an interdisciplinary study of the relationship between the economic and social histories of built space and the Victorian literary imagination. At its most fundamental level, it claims that the spaces we inhabit shape the stories we tell. Reading Victorian literature through the architectural archive of the period, it argues that the nineteenth century’s rapidly evolving built environment resulted in a new set of narrative possibilities and laid the foundations for authorial innovations in genre, style, and form. Organized taxonomically around four architectural types reinvented in the nineteenth century—courthouses, …

Go to article

Protein-Nanoparticle Co-Engineering: Self-Assembly, Intracellular Protein Delivery, And Crispr/Cas9-Based Gene Editing, Rubul Mout Nov 2017

Protein-Nanoparticle Co-Engineering: Self-Assembly, Intracellular Protein Delivery, And Crispr/Cas9-Based Gene Editing, Rubul Mout

Doctoral Dissertations

Direct cytoplasmic delivery of gene editing nucleases such CRISPR/Cas9 systems and therapeutic proteins provides enormous opportunities in curing human genetic diseases, and assist research in basic cell biology. One approach to attain such a goal is through engineering nanotechnological tools to mimic naturally existing intra- and extracellular protein delivery/transport systems. Nature builds transport systems for proteins and other biomolecules through evolution-derived sophisticated molecular engineering. Inspired by such natural assemblies, I employed molecular engineering approaches to fabricate self-assembled nanostructures to use as intracellular protein delivery tools. Briefly, proteins and gold nanoparticles were co-engineered to carry complementary electrostatic recognition elements. When these …

Go to article

Amount Relatives Redux, Jon Ander Mendia Nov 2017

Amount Relatives Redux, Jon Ander Mendia

Doctoral Dissertations

This dissertation provides a novel analysis of Amount Relatives (Carlson 1977, Heim 1987, Grosu & Landman 1998, Herdan 2008, Meier 2015, a.o). Amount Relatives are a form of non-intersective relative clause that is usually associated with amount interpretations . For example, the sentence it will take us the rest of our lives to drink the champagne they spilled that evening is most naturally interpreted as referring to an amount of champagne, and not any particular champagne. Previous accounts of Amount Relatives have converged in appealing to degree semantics in order to extract an amount from the relative clause, suggesting that …

Go to article

Who Ate The Subfossil Lemurs? A Taphonomic And Community Study Of Raptor, Crocodylian And Carnivoran Predation Of The Extinct Quaternary Lemurs Of Madagascar., Lindsay Meador Nov 2017

Who Ate The Subfossil Lemurs? A Taphonomic And Community Study Of Raptor, Crocodylian And Carnivoran Predation Of The Extinct Quaternary Lemurs Of Madagascar., Lindsay Meador

Doctoral Dissertations

Madagascar’s Quaternary predator-primate guild included seventeen species of relatively large extinct lemurs. Sharing the landscape with the lemurs, were several relatively large now-extinct predators, including three raptors (two species of Aquila and Stephanoaetus mahery), a euplerid (Cryptoprocta spelea), and a crocodile (Voay robustus). This is the first research to systematically study predator-prey relationships among these extinct animals. Here I examine the bones of the extinct lemurs at six subfossil localities (Ampasambazimba, Ankarana, Grotte d’Ankazoabo, Beloha Anavoha, Manombo Toliara, and Tsirave) for evidence of and also collected metric data on these bones. I examined 1141 specimens …

Go to article

Investigating The Impact Of Student Opt Out On Value-Added Measures Of Teacher Quality, Joshua Marland Nov 2017

Investigating The Impact Of Student Opt Out On Value-Added Measures Of Teacher Quality, Joshua Marland

Doctoral Dissertations

Student assessment nonparticipation (or opt out) has increased substantially in K-12 schools in states across the country. This increase in opt out has the potential to impact achievement and growth measures used for educator and institutional accountability. This simulation study investigates the extent to which value-added measures of teacher quality are impacted as a result of varying degrees of opt out, as well as various types of nonrandom opt out. Results show that the magnitude of opt out has a greater impact on stability of value-added estimates than the type of nonrandom opt out patterns simulated in this study, with …

Go to article

Temporal And Relational Models For Causality: Representation And Learning, Katerina Marazopoulou Nov 2017

Temporal And Relational Models For Causality: Representation And Learning, Katerina Marazopoulou

Doctoral Dissertations

Discovering causal dependence is central to understanding the behavior of complex systems and to selecting actions that will achieve particular outcomes. The majority of work in this area has focused on propositional domains, where data instances are assumed to be independent and identically distributed (i.i.d.). However, many real-world domains are inherently relational, i.e., they consist of multiple types of entities that interact with each other, and temporal, i.e., they change over time. This thesis focuses on causal modeling for these more complex relational and temporal domains. This thesis provides an in-depth investigation of the properties of relational models and is …

Go to article

Demanding Spaces: 1970s U.S. Women's Novels As Sites Of Struggle, Kate Marantz Nov 2017

Demanding Spaces: 1970s U.S. Women's Novels As Sites Of Struggle, Kate Marantz

Doctoral Dissertations

This dissertation offers a new view of 1970s gender and race politics in the United States by analyzing struggles in and over space in four women’s novels: Joan Didion’s Play It As It Lays (1970), Toni Morrison’s Sula (1973), Alice Walker’s Meridian (1976), and Marilyn French’s The Women’s Room (1977). My project reads space as a dynamic, politically charged realm of interactions between lived bodies, physical landscapes, and imaginative territories—including the formal characteristics of fiction. Using this critical lens, I highlight how these authors interrogate conditions of sexism and racism by representing their characters making and responding to “demands” for …

Go to article

Regulated Proteolysis Of Dnaa Coordinates Cell Growth With Stress Signals In Caulobacter Crescentus, Jing Liu Nov 2017

Regulated Proteolysis Of Dnaa Coordinates Cell Growth With Stress Signals In Caulobacter Crescentus, Jing Liu

Doctoral Dissertations

DNA replication is an essential process in all domains of life. Replication must be precisely regulated, especially at the step of initiation. In bacteria, the replication initiator DnaA is regulated by multiple post-translational regulations to ensure timely replication. Caulobacter crescentus has the most strict replication regulation that DNA only replicates once per cell cycle, and proteolysis of DnaA identified in this species is the only irreversible way to inhibit DnaA, suggesting it might be pivotal to restricting DNA replication. However, the responsible protease(s) and mechanism for its degradation remain unclear since its first discovery in 2005. In this thesis, I …

Go to article

Fabrication Of Functional Nano-Structured Materials And Devices Using Supercritical Fluids, Shengkai Li Nov 2017

Fabrication Of Functional Nano-Structured Materials And Devices Using Supercritical Fluids, Shengkai Li

Doctoral Dissertations

Nano-structured materials possess unconventional properties and enable miniaturization of devices. However, fabrications of such materials and devices are challenging and in many cases cumbersome, and development of nanofabrication techniques are essential to realizing novel designs and commercializing scientific ideas. Supercritical fluids possess a unique combination of gas-like diffusion properties and liquid-like dissolution power, and are suitable reaction media for fabricating materials at the nanometer scale. This dissertation focuses on developing supercritical fluids-related techniques for fast and large-scale fabrication of novel composite materials and devices. Using supercritical fluid deposition (SFD) technique, cobalt thin films were deposited on a variety of substrates, …

Go to article

Conducting Polyelectrolyte Complexes: Assembly, Structure, And Transport, Michael A. Leaf Nov 2017

Conducting Polyelectrolyte Complexes: Assembly, Structure, And Transport, Michael A. Leaf

Doctoral Dissertations

Decades of progress have yielded a tremendous variety of organic electronics, with great strides in the development of photovoltaics, thermoelectrics and other flexible devices. Ubiquitous in these research areas are films of poly(3,4-ethylenedioxythiophene): poly(styrenesulfonic acid) (PEDOT: PSS), a complex of oppositely-charged polyelectrolytes initially suspended in water before film formation. This material has high electronic conductivity and good water processability. Pristine film conductivity is somewhat low, but is dramatically enhanced through simple treatments like ionic liquid addition or shear. Can this enhancement be understood so that further optimization might render PEDOT: PSS commercially viable? PEDOT: PSS is a complicated material, with …

Go to article

Sex Differences In Estradiol Signaling In The Zebra Finch (Taeniopygia Gutatta) Auditory Cortex, Amanda Krentzel Nov 2017

Sex Differences In Estradiol Signaling In The Zebra Finch (Taeniopygia Gutatta) Auditory Cortex, Amanda Krentzel

Doctoral Dissertations

Although several sex differences have been described in brain structure, function, and development, sex as a biological factor is underrepresented in neuroscience studies. In the mammalian brain, there are sex differences in the mechanism of rapid estradiol actions on neuronal physiology. In the songbird, the brain is a major source of estradiol production, and estradiol rapidly modulates auditory responsiveness through dynamic changes and an unknown receptor mechanism. I set out to determine if there are sex differences in rapid estradiol modulation of auditory cortical activity, as has been shown in other systems. I tested this hypothesis through three aims: 1) …

Go to article

Bio-Based Wind Turbine Blades: Renewable Energy Meets Sustainable Materials For Clean, Green Power, Rachel Koh Nov 2017

Bio-Based Wind Turbine Blades: Renewable Energy Meets Sustainable Materials For Clean, Green Power, Rachel Koh

Doctoral Dissertations

Wood, once the material of choice for wind turbine blades, was phased out in the late 20th century as the growing size of blades imposed stricter material requirements and glass- and carbon-fiber composites gained industry popularity. However, the last several years have seen great advances in bio-based composite materials technology, including flax, hemp, and wood composites and laminates. These materials are increasingly utilized in high-performance, structurally demanding applications, largely because they are a more sustainable choice than many other engineering materials. Today, as the first glass-fiber wind turbine blades are ready to retire, wind developers are presented with an enormous …

Go to article

Using Exemplar Items To Define Performance Categories: A Comparison Of Item Mapping Methods, Ana Karantonis Nov 2017

Using Exemplar Items To Define Performance Categories: A Comparison Of Item Mapping Methods, Ana Karantonis

Doctoral Dissertations

Score reporting is an extremely important and yet often neglected component of large-scale assessment programs. One element of score reporting that frequently leads to misunderstanding is the interpretation of performance levels. One way to help define performance levels is through the use of "exemplars." Exemplars are test items that are supposed to best characterize each performance level. In this study, a Monte Carlo simulation was conducted to examine the performance of two item-mapping methods and different criteria for identifying exemplars under several simulated conditions. The results of the study were neither clear nor systematic across all conditions and performance levels; …

Go to article

Equations For Nilpotent Varieties And Their Intersections With Slodowy Slices, Benjamin Johnson Nov 2017

Equations For Nilpotent Varieties And Their Intersections With Slodowy Slices, Benjamin Johnson

Doctoral Dissertations

This thesis investigates minimal generating sets of ideals defining certain nilpotent varieties in simple complex Lie algebras. A minimal generating set of invariants for the whole nilpotent cone is known due to Kostant. Broer determined a minimal generating set for the subregular nilpotent variety in all simple Lie algebra types. I extend Broer's results to two families of nilpotent varieties, valid in any simple Lie algebra, that include the nilpotent cone, the subregular case, and usually more. In the first part of my thesis I describe a minimal generating set for the ideal of each of these varieties in the …

Go to article

Tissue-Guided Engineering Of Polyethylene Glycol Hydrogels, Lauren Jansen Nov 2017

Tissue-Guided Engineering Of Polyethylene Glycol Hydrogels, Lauren Jansen

Doctoral Dissertations

Polyethylene glycol (PEG) hydrogels are tunable cell culture platforms that recapitulate tissue geometry, water content, and bulk modulus. Despite these benefits, PEG hydrogels elicit an acute immune response, limiting their use in regenerative medicine, and they critically underrepresent the cell-instructive proteins found in the extracellular matrix (ECM). Here, I developed a new class of tissue-specific PEG-based materials and provided biocompatible strategies to improve the user handling and cell viability post-encapsulation when using these hydrogels. I also demonstrated that decreasing the protein fouling to PEG does not decrease the foreign body response to implanted hydrogels, a common misconception in the field. …

Go to article

Deep-Learned Generative Representations Of 3d Shape Families, Haibin Huang Nov 2017

Deep-Learned Generative Representations Of 3d Shape Families, Haibin Huang

Doctoral Dissertations

Digital representations of 3D shapes are becoming increasingly useful in several emerging applications, such as 3D printing, virtual reality and augmented reality. However, traditional modeling softwares require users to have extensive modeling experience, artistic skills and training to handle their complex interfaces and perform the necessary low-level geometric manipulation commands. Thus, there is an emerging need for computer algorithms that help novice and casual users to quickly and easily generate 3D content. In this work, I will present deep learning algorithms that are capable of automatically inferring parametric representations of shape families, which can be used to generate new 3D …

Go to article

First Prev Next Last