Digital Commons Network^™

The Effects Of Gamifying Optional Lessons On Motivation, Aaron Zemach

McKelvey School of Engineering Theses & Dissertations

Adding video-game elements to non-video-game interfaces (“gamification”) has become a common engagement strategy over the past several years in the domain of education. While prior studies have found that adding game elements to mandatory educational materials can increase students’ motivation to complete the materials, there has yet to be a study to investigate if game elements can make users more likely to engage with optional educational materials. In this study, we investigate whether users of a gamified educational interface are more motivated than users of a non-gamified interface to voluntarily complete educational materials. We found users of a gamified interface …

Novel Mobile Computation Offloading Framework For Android Devices, Meng Wang

McKelvey School of Engineering Theses & Dissertations

The thesis implements an offloading framework for GoogleTM AndroidTM based on mobile devices. Today, the full potential for smartphones may be constrained by certain technical limits such as battery endurance and computational performance. Modern mobile applications own more powerful functions but need larger computation and faster frame rate, which consume more battery energy. Using the proposed offloading framework, mobile devices can offload computational intensive workload to servers to save battery energy consumption and reduce the execution time. The framework can also enable software developers to easily build and deploy services on the servers to support mobile devices to run computationally …

Real-Time Temperature Imaging Using Ultrasonic Change In Backscattered Energy, Weiyuan Zhao

McKelvey School of Engineering Theses & Dissertations

Thermal therapy from low-temperature cryosurgery to high-temperature ablation of tumors and unwanted electrical pathways has gained increased attention. Temperature imaging (TI) from magnetic resonance studies is the de facto standard for volumetric estimation of temperature. Ultrasound has the advantages of being cheap, portable, non-invasive and non-ionizing. Our group showed in predictions for single scatterers, simulations of scatterer populations and measurements in 1D, 2D and 3D, that CBE changed monotonically with temperature with 1^oC accuracy. An obstacle to clinical application of CBE TI is estimation of temperature in real time, which is limited by time for motion compensation (MC). …

Ultrasound-Mediated Optical Imaging And Focusing In Scattering Media, Yuta Suzuki

McKelvey School of Engineering Theses & Dissertations

Because of its non-ionizing and molecular sensing nature, light has been an attractive tool in biomedicine. Scanning an optical focus allows not only high-resolution imaging but also manipulation and therapy. However, due to multiple photon scattering events, conventional optical focusing using an ordinary lens is limited to shallow depths of one transport mean free path (lt'), which corresponds to approximately 1 mm in human tissue.

To overcome this limitation, ultrasonic modulation (or encoding) of diffuse light inside scattering media has enabled us to develop both deep-tissue optical imaging and focusing techniques, namely, ultrasound-modulated optical tomography (UOT) and time-reversed ultrasonically encoded …

Contextualized Robot Navigation, David Vincent Lu

McKelvey School of Engineering Theses & Dissertations

In order to improve the interaction between humans and robots, robots need to be able to move about in a way that is appropriate to the complex environments around them. One way to investigate how the robots should move is through the lens of theatre, which provides us with ways to analyze the robot's movements and the motivations for moving in particular ways. In particular, this has proven useful for improving robot navigation. By altering the costmaps used for path planning, robots can navigate around their environment in ways that incorporate additional contexts. Experimental results with user studies have shown …

An Essential Role For Self-Pmhc Throughout The Life Of A Cd4 T Cell: Contributions In The Thymus And Periphery, Stephanie Rodriguez

Arts & Sciences Electronic Theses and Dissertations

It is well established that self-peptide Major Histocompatibility Complexes (hereafter self-pMHC) are essential for the development of a broad repertoire of mature, self-tolerant CD4 and CD8 T cells. Despite clear knowledge that the pool of self-ligands is critical for positive and negative selection, the exact kinetics and dynamic nature of thymocyte interaction with self-pMHC class II (self-pMHCII) bearing antigen-presenting cells (APCs) during development is still largely a mystery. The enigmatic nature of selecting self-pMHC is not unique to the thymic environment; increasingly evident is the dependence of peripheral T cells on extra-thymic self-pMHC expression, specifically selecting self-pMHC, for their homeostatic …

Synthesis And Characterization Of Pbs Quantum Sheets Through Lamellar Assembly, And Updates To The Cdse Quantum Wire Synthesis, Paul James Morrison

Arts & Sciences Electronic Theses and Dissertations

This dissertation reports the novel synthesis of PbS quantum plates (QPs) via a reaction executed at low temperatures. The PbS QPs are grown in a template-assisted mechanism, with the first excitonic peak observed in the visible region of light at ~620 nm (2.0 eV), at an energy radically different than the band gap of bulk PbS (~3000 nm, 0.42eV). The large energy shift is due to the extremely thin dimension of these nanoplates, which is determined to be ~1 nm in thickness. Thickness measurements are made in a powder X-ray diffractometer (XRD) at low angles (between 2-15º 2θ). These measurements …

Gothic Literature And The Politics Of Indistinction, Nicholas Everett Miller

Arts & Sciences Electronic Theses and Dissertations

I recover the Gothic as a literature of political possibility. While scholars have long associated the Gothic tradition with political fear, I argue that Gothic novels challenge liberal ideas of the self to produce a sometimes radically egalitarian politics of freedom in the late-eighteenth and early-nineteenth centuries. Edmund Burke made much of the fearfulness of an egalitarian politics in the 1790s, and literary historians have relied on his influence to argue that Gothic fiction is primarily an expression of the fear that comes with the collapse of familial, social, and political distinctions. But fear is not all that accompanies such …

A Liberal State Of Mind: Formal Reconstructions Of Statehood In The Anglophone African Novel, Maya Ganapathy

Arts & Sciences Electronic Theses and Dissertations

While the idea of the nation and national identity is often taken as the starting point for examinations of the African state, this dissertation explores the transnational dimensions of the African novel and the way in which English-language writers from Africa imagine a state that more adequately captures their desire to freely inhabit a global literary marketplace. Although critics of the Anglophone African novel tend to understand the fictional state as an object of unremitting political critique (often simply as a reflection of its real-world counterpart), the African state, when viewed through the methodological lens of narrative form, becomes the …

The Boundaries Of Youth: Labor, Maturity, And Coming Of Age In Early Nineteenth-Century New England, 1790-1850, Jane Fiegen Green

Arts & Sciences Electronic Theses and Dissertations

This project uses the experiences of young men and women to show how the language of maturity laid a foundation for the mythology of democratic capitalism in nineteenth-century America. Freed from the bounds of the household but left to the mercy of the emerging capitalist economy, young New Englanders struggled to reconcile the democratic ideals of work with the realities of class stratification. Expected to show their self-ownership through the performance of gender-defined employment, young men and women used their work experiences to display their maturity. Recognition as competent, mature adults required young people to find and demonstrate independence through …

The Automatic And Controlled Influence Of Environmental Cues During Recognition Judgments, Diana Selmeczy

Arts & Sciences Electronic Theses and Dissertations

Recognition judgments are often made in the context of environmental information, such as instructions or payout regimens that observers have been shown to use in order to adaptively bias their memory judgments. These adaptive biases are usually characterized as a strategic, controlled process that observers adopt intentionally, and this is formalized in signal detection theory wherein strategic criterion placement is assumed fully independent of recognition evidence signals. However, recent pilot research in our laboratory suggests that the ability to regulate recognition decision biases in the context of environmental cues may not be fully controlled by observers suggesting an automatic or …

Power To Appoint: A Model Of Appointments To The United States Federal Judiciary, Alicia Bernice Uribe

Arts & Sciences Electronic Theses and Dissertations

This dissertation project considers judicial appointments in a new light. The project, first, considers how appointments to the United States Federal Judiciary might be thought of differently if the appointment to multiple positions were thought of as interdependent decisions rather than independent decisions. I create a simulation based model that matches judges with vacant positions in the judiciary to see how our expectations of appointments should differ for different levels of the judiciary and in different political environments. I then consider how this approach might translate to other selection mechanisms comparing the selection system for the federal judiciary with other …

Childhood Poverty And Psychological Health Of Youths In Hong Kong: Mentoring As A Social Capital Intervention, Hor Yan Lai

Arts & Sciences Electronic Theses and Dissertations

Considering that one out of five youths live in poverty in Hong Kong, and poverty is found to have a negative impact on youths' psychological well-being, this dissertation proposes mentoring as a social capital intervention to improve the psychological health of these young people, both who are locally born and who immigrated from Mainland China. In this dissertation, mentoring is defined as a social capital intervention that changes the social resources available to youths living in poverty, and such changes enhance young people's positive psychological outcomes. Based on the social capital theory, poverty-related and psychological theories, three aims were formulated. …

Polyol Synthesis Of Silver Nanowires By Heterogeneous Nucleation And Mechanistic Aspects Influencing Its Length And Diameter, Waynie M. Schuette

Arts & Sciences Electronic Theses and Dissertations

Various additives are employed in the polyol synthesis of silver nanowires (Ag NWs), which are typically halide salts such as NaCl. A variety of mechanistic roles have been suggested for these additives. My research showed that the early addition of NaCl in the polyol synthesis of Ag NWs from AgNO3 in ethylene glycol results in the rapid formation of AgCl nanocubes, which induce the heterogeneous nucleation of metallic Ag upon their surfaces. Ag NWs subsequently grow from these nucleation sites. The conclusions are supported by studies using ex-situ generated AgCl nanocubes.

Additionally, the final mean silver nanowire diameter is found …

Origin Of Maternal Age Effect In Congenital Heart Disease Risk For Offspring, Claire Elaine Schulkey

Arts & Sciences Electronic Theses and Dissertations

Increasing maternal age is widely acknowledged to lead to greater likelihood of pregnancy complications and congenital abnormalities, but the basis of this effect has not been well studied. Often dismissed as the product of oocyte ageing, the mechanistic basis of this maternal age effect is likely more complex.

Congenital heart disease is a classic complex disease with multiple genetic and environmental modifiers, including maternal age. Maternal ageing is a known risk-factor in humans, and has been shown to exist in an Nkx2-5 haploinsufficient mouse model for the disease. This mouse model's maternal age risk is dependent upon strain background, with …

Commentary, Illustration, And Cross-Generic Writing In Paired Editions Of Xixiang Ji And Pipa Ji, Yinghui Wu

Arts & Sciences Electronic Theses and Dissertations

This study examines the reproduction and consumption of popular playsXixiang ji(The Story of the Western Wing) andPipa ji(The Lute) as a related pair in seventeenth-century China. During this period, a thriving economy and rapid urbanization stimulated the expansion of commercial publishing. A book market flourished with a bewildering variety of texts and pictures and inventive regroupings of existing materials. Seventeenth-century China has long been recognized as an age of individual creativity, with the elite literati as primary agents, but this study revises the picture by directing attention to the appropriation and transformation of the cultural ideal of "creativity" through the …

Real-Time And Energy-Efficient Routing For Industrial Wireless Sensor-Actuator Networks, Chengjie Wu

McKelvey School of Engineering Theses & Dissertations

With the emergence of industrial standards such as WirelessHART, process industries are adopting Wireless Sensor-Actuator Networks (WSANs) that enable sensors and actuators to communicate through low-power wireless mesh networks. Industrial monitoring and control applications require real-time communication among sensors, controllers and actuators within end-to-end deadlines. Deadline misses may lead to production inefficiency, equipment destruction to irreparable financial and environmental impacts. Moreover, due to the large geographic area and harsh conditions of many industrial plants, it is labor-intensive or dan- gerous to change batteries of field devices. It is therefore important to achieve long network lifetime with battery-powered devices.

This dissertation …

The Late Ordovician Biogeochemical Carbon Cycle, John Garrecht Metzger

Arts & Sciences Electronic Theses and Dissertations

The isotopic composition of the carbonate carbon (δ13Ccarb) is one of the best tools for understanding the biogeochemical carbon cycle through Earth history. δ13Ccarb is also used to chemostratigraphically correlate coeval strata. This dissertation has three main foci that all utilize δ13Ccarb as the common data type. The geologic interval investigated was the Late Ordovician (458-444 Ma) with emphasis on the Guttenberg δ13C excursion, a globally correlated, positive ~3 / event that is ~400 kyr in duration. In the first topic we evaluate post-depositional alteration (i.e., diagenesis) of δ13Ccarb signals. In the second topic, we make reconstructions of sea level …

Accelerating Heuristic Search For Ai Planning, You Xu

McKelvey School of Engineering Theses & Dissertations

AI Planning is an important research field. Heuristic search is the most commonly used method in solving planning problems. Despite recent advances in improving the quality of heuristics and devising better search strategies, the high computational cost of heuristic search remains a barrier that severely limits its application to real world problems. In this dissertation, we propose theories, algorithms and systems to accelerate heuristic search for AI planning.

We make four major contributions in this dissertation. First, we propose a state-space reduction method called Stratified Planning to accelerate heuristic search. Stratified Planning can be combined with any heuristic search to …

Study Of Ii-Vi Colloidal Semiconductor Magic-Size Nanoclusters And Crystalline Quantum Platelets, Yuanyuan Wang

Arts & Sciences Electronic Theses and Dissertations

The main objective of this project is to prepare and isolate the smallest, discrete, magic-size nanoclusters of cadmium selenide (CdSe) and to grow crystalline, wurtzite CdSe quantum platelets (QPs) at room temperature. The achievement of these goals enables us to provide a general synthesis of II-VI semiconductor magic-size nanoclusters and low-temperature routes to well-passivated nanocrystals having a range of compositions and morphologies.

The magic-size nanocluster (CdSe)13 is grown in a lamellar-bilayer soft template at room temperature. The results described in this thesis strongly suggest that [(CdSe)13(n-octylamine)13] is the most thermodynamically stable nanocluster and serves as a key intermediate in the …

Approximation And Relaxation Approaches For Parallel And Distributed Machine Learning, Stephen Tyree

McKelvey School of Engineering Theses & Dissertations

Large scale machine learning requires tradeoffs. Commonly this tradeoff has led practitioners to choose simpler, less powerful models, e.g. linear models, in order to process more training examples in a limited time. In this work, we introduce parallelism to the training of non-linear models by leveraging a different tradeoff--approximation. We demonstrate various techniques by which non-linear models can be made amenable to larger data sets and significantly more training parallelism by strategically introducing approximation in certain optimization steps.

For gradient boosted regression tree ensembles, we replace precise selection of tree splits with a coarse-grained, approximate split selection, yielding both faster …

The Impacts Of Climate Change On The World’S Economic, Political, And Demographic Structures, Dino Kanlic

Arts & Sciences Electronic Theses and Dissertations

Climate change will have negative impacts on the political, economic, and demographic structures of society. These include a rise in ethnic tensions in the Indian Sub Continent, massive immigration to Europe, regional economic collapse and political destabilization in Africa, the inundation of island nations and economic losses in the Americas among many other changes which will combine to destabilize humanity for generations. International affairs has failed to come up with a solution because global warming is a universal prevention focused problem that trades short term gains for long term losses. Global warming will be solved by the onset of grid …

Comparison Of Conventional And Bayesian Analysis For The Ultrasonic Characterization Of Cancellous Bone, Amber Groopman

Arts & Sciences Electronic Theses and Dissertations

This dissertation investigates the physics underlying the propagation of ultrasonic waves in cancellous bone. Although quantitative ultrasound has the potential to evaluate bone quality even better than the current gold standard X-ray based modality, its clinical utility has been hampered by the incomplete understanding of the mechanisms governing the interaction between ultrasound and bone. Therefore, studies that extend the understanding of the fundamental physics of the relationship between ultrasound and trabecular bone tissue may result in improved clinical capabilities.

Ultrasonic measurements were carried out on excised human calcaneal specimens in order to study the effects of overlapping fast and slow …

The Influence Of Metacommunity Size On Species Diversity Across Spatial Scales, Lauren Woods

Arts & Sciences Electronic Theses and Dissertations

This dissertation explores the influence of metacommunity size and landscape level processes, such as dispersal, on species diversity. A metacommunity is a group of local communities, or patches, connected by dispersal, and metacommunity size can be defined as the number of discrete local patches within a metacommunity. In chapter 1, I developed a framework to predict the effects of habitat destruction, or a reduction in metacommunity size, on the species richness of local patches of different sizes by integrating metacommunity theory with the equilibrium theory of island biogeography. The effect of metacommunity size on species richness in small and large …

When Life Happens: Theatres Of Hiv And Complexity In South Africa, Jessica S. Ruthven

Arts & Sciences Electronic Theses and Dissertations

This dissertation examines theatre as part of an artistic movement in South Africa to address the social, structural, and emotional repercussions of HIV, as well as a space in which knowledge about HIV/AIDS is actively created, mediated, reproduced, challenged, and presented for public consumption. Although applied theatre has a long history in the country, I focus on innovation in recent theatrical practices that have occurred as artists and members of broader civil society struggle to understand the trajectory of the country's AIDS epidemic and question the scope of popular national HIV intervention campaigns. I use emerging forms of cultural production …

Modulation Of Nmda Receptor Activity During Physiological And Pathophysiological Events, Christine Marie Emnett

Arts & Sciences Electronic Theses and Dissertations

N-methyl-D-aspartate receptors (NMDARs) are ionotropic glutamate receptors that serve crucial signaling and neurotrophic functions throughout the central nervous system. Both hyperfunction and hypofunction of NMDARs are associated with neurological and neuropsychiatric conditions. Thus, both positive and negative pharmacological NMDAR modulators are of clinical interest as treatments. Understanding drug mechanisms could lead to more rational drug design. Memantine and ketamine are NMDAR open channel blockers that exhibit similar pharmacodynamics at NMDARs but have different clinical uses. Memantine improves cognitive decline during Alzheimer's disease. Ketamine is an anesthetic and analgesic with psychotomimetic effects, but it is also a rapid acting and long-lived …

Isotope Harvesting At Heavy-Ion Fragmentation Facilities, Tara Elise Mastren

Arts & Sciences Electronic Theses and Dissertations

Isotope harvesting from heavy-ion fragmentation facilities is a potential source of isotopes of interest for applications research. With the upgrade of the National Superconducting Cyclotron Laboratory (NSCL) to the Facility for Rare Isotope Beams (FRIB) usable quantities of many isotopes of interest will be produced and available for harvest from an aqueous beam dump. If available, these isotopes would be of interest to a broad range of applications such as medicine, geology, and stockpile stewardship. Preliminary experiments were performed at the NSCL in order to determine the feasibility of isotope harvesting at (FRIB).

A water target station that consisted of …

Kinetic Analysis And Inhibition Studies Of Iron-Dependent Histone Demethylases, Barbara Gordon Cascella

Arts & Sciences Electronic Theses and Dissertations

The research presented herein focuses on the kinetics and inhibition of the KDM4 subfamily of Jumonji C (JmjC) domain-containing histone demethylases (HDMs). Belonging to the larger class of alpha-ketoglutarate (alpha-KG)-dependent, non-heme iron monooxygenases, the JmjC-HDMs remove methyl groups from mono-, di-, and tri-methylated histone lysine residues through an Fe(IV)-oxo-catalyzed hydroxylation reaction. JmjC-HDMs have been found to play integral roles in the maintenance of genomic integrity as well as in the regulation of transcription. Three KDM4 members were studied: the mixed H3K9/H3K36 demethylases KDM4A and KDM4C, and the pure H3K9 demethylase KDM4E. KDM4C is a hypoxia-inducible factor 1 (HIF-1) target gene …

Applications Of Nonlinear Optimization, Yao Xie

Arts & Sciences Electronic Theses and Dissertations

We apply an interior point algorithm to two nonlinear optimization problems and achieve improved results. We also devise an approximate convex functional alternative for use in one of the problems and estimate its accuracy.

The first problem is maximum variance unfolding in machine learning. The traditional method to solve this problem is to convert it to a semi-definite optimization problem by defining a kernel matrix. We obtain better unfolding and higher speeds with the interior point algorithm on the original non-convex problem for data with less than 10,000 points.

The second problem is a multi-objective dose optimization for intensity modulated …

Zinc And Copper Isotopic Fractionation During Planetary Differentiation, Heng Chen

Arts & Sciences Electronic Theses and Dissertations

Zinc and copper are two important transition metal elements that are widely involved in every stage of planetary formation and differentiation. Their isotopic ratios are robust tracers used to understand the origin of the Solar System, planetary formation and differentiation processes. In this thesis, I focus on their isotopic behaviors during magmatic processes. I report the Zn isotopic compositions of representative igneous rocks to determine potential isotopic fractionations associated with magmatic processes, and to estimate the bulk silicate Earth value. I report isotopic compositions of various groups of iron meteorites (samples of which represent the core of asteroids) and discuss …