Physical Sciences and Mathematics Commons^™

Quantum Transport In Topological Magnets, Haiming Deng

Dissertations, Theses, and Capstone Projects

In the past several years, a new field of symmetry-protected topological materials has emerged in condensed matter physics, based on the wide range of consequences that result from the realization that certain properties of physical systems can be expressed as topological invariants, which are insensitive to local perturbations. This new class of materials hosts unique surface/edge states, such as the first known topological system – quantum Hall insulator with dissipationless chiral edge states, and massless spin-helical Dirac surface states in 3D topological insulators that are unlike any other known 1D or 2D electronic systems. In this thesis, to understand the …

Towards Automated Software Evolution Of Data-Intensive Applications, Yiming Tang

Dissertations, Theses, and Capstone Projects

Recent years have witnessed an explosion of work on Big Data. Data-intensive applications analyze and produce large volumes of data typically terabyte and petabyte in size. Many techniques for facilitating data processing are integrated into data-intensive applications. API is a software interface that allows two applications to communicate with each other. Streaming APIs are widely used in today's Object-Oriented programming development that can support parallel processing. In this dissertation, an approach that automatically suggests stream code run in parallel or sequentially is proposed. However, using streams efficiently and properly needs many subtle considerations. The use and misuse patterns for stream …

Data Analysis And Visualization To Dismantle Gender Discrimination In The Field Of Technology, Quinn Bolewicki

Dissertations, Theses, and Capstone Projects

In the United States, a significant population is facing an uphill battle trying to thrive in an industry that has seen exponential growth in recent years. Women, who account for approximately 50.8% of the U.S. population are statistically underpaid and underrepresented in science, technology, engineering, and mathematics (STEM). Despite women-led technology teams establishing a 21% greater return on investment than teams who don’t, and young women largely outperforming men in math according to a 2015 study, there are only three fortune 500 companies led by women, and they comprise only 10% of internet entrepreneurs. Research generates hundreds of articles, infographics, …

Fabrication Of Nd3+ And Yb3+ Doped Nir Emitting Nano Fluorescent Probe: A Candidate For Bioimaging Applications, D. Karthickraja, G. A. Kumar, D. K. Sardar, S. Karthi, Gamage C. Dannangoda, Karen S. Martirosyan, M. Prasath, M. Gowri, E. L. Girija

Physics and Astronomy Faculty Publications and Presentations

The intentional design of rare earth doped luminescent architecture exhibits unique optical properties and it can be considered as a promising and potential probe for optical imaging applications. Calcium fluoride (CaF2) nanoparticles doped with optimum concentration of Nd3+ and Yb3+ as sensitizer and activator, respectively, were synthesized by wet precipitation method and characterized by x-ray diffraction (XRD) and photoluminescence. In spite of the fact that the energy transfer takes place from Nd3+ to Yb3+, the luminescence intensity was found to be weak due to the lattice defects generated from the doping of trivalent cations (Nd3+ and Yb3+) for divalent host …

A Survey Of Computer Graphics Facial Animation Methods: Comparing Traditional Approaches To Machine Learning Methods, Joseph A. Johnson

Master's Theses

Human communications rely on facial expression to denote mood, sentiment, and intent. Realistic facial animation of computer graphic models of human faces can be difficult to achieve as a result of the many details that must be approximated in generating believable facial expressions. Many theoretical approaches have been researched and implemented to create more and more accurate animations that can effectively portray human emotions. Even though many of these approaches are able to generate realistic looking expressions, they typically require a lot of artistic intervention to achieve a believable result. To reduce the intervention needed to create realistic facial animation, …

Real-Time Stylized Rendering For Large-Scale 3d Scenes, Jack Pietrok

Master's Theses

While modern digital entertainment has seen a major shift toward photorealism in animation, there is still significant demand for stylized rendering tools. Stylized, or non-photorealistic rendering (NPR), applications generally sacrifice physical accuracy for artistic or functional visual output. Oftentimes, NPR applications focus on extracting specific features from a 3D environment and highlighting them in a unique manner. One application of interest involves recreating 2D hand-drawn art styles in a 3D-modeled environment. This task poses challenges in the form of spatial coherence, feature extraction, and stroke line rendering. Previous research on this topic has also struggled to overcome specific performance bottlenecks, …

Modeling The Spread Of Covid-19 Over Varied Contact Networks, Ryan L. Solorzano

Master's Theses

When attempting to mitigate the spread of an epidemic without the use of a vaccine, many measures may be made to dampen the spread of the disease such as physically distancing and wearing masks. The implementation of an effective test and quarantine strategy on a population has the potential to make a large impact on the spread of the disease as well. Testing and quarantining strategies become difficult when a portion of the population are asymptomatic spreaders of the disease. Additionally, a study has shown that randomly testing a portion of a population for asymptomatic individuals makes a small impact …

Exploring The Use Of Social Media To Infer Relationships Between Demographics, Psychographics And Vaccine Hesitancy, Abhimanyu Kapur

Computer Science Senior Theses

The growing popularity of social media as a platform to obtain information and share one's opinions on various topics makes it a rich source of information for research. In this study, we aimed to develop a framework to infer relationships between demographic and psychographic characteristics of a user and their opinion on a specific narrative - in this case, their stance on taking the COVID-19 vaccine. Twitter was the chosen platform due to the large USA user base and easily available data. Demographic traits included Race, Age, Gender, and Human-vs-Organization Status. Psychographic traits included the Big Five personality traits (Conscientiousness, …

Algal Alterity : A Study Of Florida's Algae-Crisis-Culture, Katelyn Flood

Masters Theses

This research critically engages with the ecology of media discourse surrounding Florida’s “harmful algae crisis” . It uses a content analysis of online news media articles to address how the presence and unique processes of aquatic algae organisms are entangled with people and cultural practices. Specifically, this work grapples with the dynamic relationship between algae organisms and the cultural production of meaning through visual imagery/stimuli. It examines both visual and textual representations of algae in mass media communications covering the harmful algae crisis or “red tide crisis” of 2017 and 2018: an extreme period of aquatic algae proliferation and hazardous …

Why Do Robots Have Smiley Faces?, Mark Findlay

Research Collection Yong Pung How School Of Law

The author discussed why engineers and designers provide machines with the semblance of friendliness, and why it takes more than that for humans to trust AI. The ground-breaking AI in community research and policy initiative by CAIDG, supported by the National Research Foundation Singapore under its Emerging Areas Research Projects Funding Initiative, seeks to understand how and why trust can be established when humans and machines come together.

Methods For Extending Biomedical Reference Ontologies And Interface Terminologies For Ehrr Text Annotation, Vipina Kuttichi Keloth

Dissertations

Biomedical ontologies and terminologies are a cornerstone in various electronic health record systems (EHRs) for encoding information related to diseases, diagnoses, treatments, etc. Ontologies in general represent entities (concepts) and events along with all interdependent properties and relationships in an efficient way to facilitate easy access, retrieval and sharing. With the landscape of medicine rapidly changing, biomedical ontologies and terminologies need to rapidly evolve to support interoperability, medical coding, record keeping, and healthcare activities in general, and to facilitate interdisciplinary research. Extending ontologies by identifying new and missing concepts plays a vital role in the maintenance of ontologies to keep …

Reconstituting The Cyanobacterial Circadian Clock In Vitro, Pyong Hwa Kim

Dissertations

Cyanobacteria are photosynthetic organisms that are known to be responsible for oxygenating Earth’s early atmosphere. Having evolved to ensure optimal survival in the periodic light/dark cycle on this planet, their genetic codes are packed with various tools, including a sophisticated biological timekeeping system. Among the cyanobacteria is Synechococcus elongatus PCC 7942, the simplest clock-harboring organism with a powerful genetic tool that enabled the identification of its intricate timekeeping mechanism. The three central oscillator proteins—KaiA, KaiB, and KaiC—drive the 24 h cyclic gene expression rhythm of cyanobacteria, and the "ticking" of the oscillator can be reconstituted inside a test tube just …

Intermittent Dynamics Of Dense Particulate Matter, Chao Cheng

Dissertations

Granular particle systems are scattered around the universe, and they can behave like solids when there exist strong force-bearing networks, so that the granular system can resist certain stress without deformation. When such a network is not present, particles yield to small stress and behave like a fluid. A wide range of systems exhibit intermittent dynamics as they are slowly loaded, with different dynamical regimes governing many industrial and natural phenomena. While a significant amount of research on exploring intermittent dynamics of granular systems has been carried out, not much is known about the connection between particle-scale response and the …

Radio Diagnostics Of Particles And Plasma In The Solar Corona, Sherry Chhabra

Dissertations

Radio diagnostics, in addition to their capabilities in exploring intense, impulsive bursts, also provide a high sensitivity to much weaker events, which may not show any substantial signature in other wavelengths.

The initial case study examines a complex event consisting of multiple radio sources/bursts associated with a fast coronal mass ejection (CME) and an M 2.1 class solar flare (SOL2015-09-20). ‘First-light’ data from the Owens Valley Radio Observatory–Long Wavelength Array is put in context with observations from Large Angle and Spectrometric Coronagraph onboard the Solar and Heliospheric Observatory, along with the WAVES radio spectrograph onboard WIND, the Expanded Owens Valley …

Development Of Deep Learning Neural Network For Ecological And Medical Images, Shaobo Liu

Dissertations

Deep learning in computer vision and image processing has attracted attentions from various fields including ecology and medical image. Ecologists are interested in finding an effective model structure to classify different species. Tradition deep learning model use a convolutional neural network, such as LeNet, AlexNet, VGG models, residual neural network, and inception models, are first used on classifying bee wing and butterfly datasets. However, insufficient data sample and unbalanced samples in each class have caused a poor accuracy. To make improvement the test accuracy, data augmentation and transfer learning are applied. Recently developed deep learning framework based on mathematical morphology …

Safe Yield Comparisons For The 1960’S And 2000’S Drought In The Passaic River Basin, Stephanie R. Santos

Dissertations

The Passaic River Basin is a complex system of rivers, tributaries, reservoirs, and some of the largest water purveyors in the State of New Jersey. Located in the northeastern part of the State, it drains approximately 800 square miles of water that is used for distribution to the five major purveyors: North Jersey District Water Supply Commission, Passaic Valley Water Commission, Jersey City, Newark, and New Jersey American Water. These purveyors operate under a safe yield, which is defined by the New Jersey Department of Environmental Protection (NJDEP) as the amount of water that should be continuously available should the …

First-Principles Density Functional Theory Studies On Perovskite Materials, Aneer Lamichhane

Dissertations

Perovskites are a family of materials with a diverse combination of different elements. As a consequence, they exhibit numerous functionalities such as pyroelectric, piezoelectric, ferroelectric, and ferromagnetic with applications in photovoltaic cells, LEDs, superconductivity, colossal magneto-resistance, and topological insulators. After 2009, perovskites have gained notoriety as suitable materials for solar cells and alternative candidates to silicon-based conventional solar cells. Generally, oxide perovskites exhibit good dielectric properties, halide perovskites display good photonic qualities, and chalcogenide perovskites are used in applications in solid-state lighting, sensing, and energy harvesting. In this dissertation, various types of perovskites ranging from oxide to halide are investigated …

Optimizing Work Zone Schedules Considering Traffic Diversion With Artificial Bee Colony Algorithm, Celina Semaan

Dissertations

Highway maintenance activities often decrease roadway capacity and intrude traffic movements. The need to finish the project on time and under a specific budget while minimizing the traffic congestion and complying with the emission standards requires an appropriate work zone schedule optimization. The objective of this research is to improve the efficiency of work zone activities and minimize the total project cost including maintenance, user, and emission cost.

While previous studies investigated the work zone optimization problem, they did not consider the implementation of emission standards nor applied a green diversion strategy. This dissertation analyzes the optimization of work zone …

Intelligent And Secure Fog-Aided Internet Of Drones, Jingjing Yao

Dissertations

Internet of drones (IoD), which utilize drones as Internet of Things (IoT) devices, deploys several drones in the air to collect ground information and send them to the IoD gateway for further processing. Computing tasks are usually offloaded to the cloud data center for intensive processing. However, many IoD applications require real-time processing and event response (e.g., disaster response and virtual reality applications). Hence, data processing by the remote cloud may not satisfy the strict latency requirement. Fog computing attaches fog nodes, which are equipped with computing, storage and networking resources, to IoD gateways to assume a substantial amount of …

Impact Of User Traversal On Performance Of Stem Learners In Immersive Virtual Environments, Eric W. Nersesian

Dissertations

The emerging technologies of augmented and virtual reality (AR/VR) may have vast implications to societal communication and representation of information. AR/VR computer interfaces are unique in that they may be placed spatially around the user in three-dimensional (3D) space; this affords new methods of both presentation and user interaction with the target information.

This may be especially impactful in the education of science, technology, engineering, and mathematics (STEM) professionals. Prior research has shown that simulations and visualizations improve the performance of STEM learners compared to live instruction and textbook reading. Yet, research into AR/VR as a learning environment for widespread …

Deep Learning On Image Forensics And Anti-Forensics, Zhangyi Shen

Dissertations

Image forensics protect the authenticity and integrity of digital images. On the contrary, as the countermeasures of digital forensics, anti-forensics is applied to expose the vulnerability of forensics tools. Consequently, forensics researchers could develop forensics tools against possible new attacks. This dissertation investigation demonstrates two image forensics methods based on convolutional neural network (CNN) and two image anti-forensics methods based on generative adversarial network (GAN).

Detecting unsharp masking (USM) sharpened image is the first study in this dissertation. A CNN architecture comprises four convolutional layers and a classification module is proposed to discriminate sharpened images and unsharpened images. The results …

Eigenvalue Problems For Fully Nonlinear Elliptic Partial Differential Equations With Transport Boundary Conditions, Jacob Lesniewski

Dissertations

Fully nonlinear elliptic partial differential equations (PDEs) arise in a number of applications. From mathematical finance to astrophysics, there is a great deal of interest in solving them. Eigenvalue problems for fully nonlinear PDEs with transport boundary conditions are of particular interest as alternative formulations of PDEs that require data to satisfy a solvability condition, which may not be known explicitly or may be polluted by noisy data. Nevertheless, these have not yet been well-explored in the literature. In this dissertation, a convergence framework for numerically solving eigenvalue problems for fully nonlinear PDEs is introduced. In addition, existing two-dimensional methods …

Global Mhd And Acoustic Solar Modeling And Helioseismic Analysis, Andrey M. Stejko

Dissertations

Computational fluid dynamic simulations have become one of the most prolific avenues of study in the fields of solar and stellar physics within the last several decades. With the advent of ever increasing computing power, high-definition global models of the Sun have become indispensable in understanding the complex and chaotic nature of flows in the solar interior, as well as their impact on the evolution of the global solar dynamo. The mechanisms that connect the generation of the toroidal magnetic field at the base of the convection zone to the emergence of a poloidal field onto the solar surface can …

Asymmetric Multivariate Archimedean Copula Models And Semi-Competing Risks Data Analysis, Ziyan Guo

Dissertations

Many multivariate models have been proposed and developed to model high dimensional data when the dimension of a data set is greater than 2 (d ≥ 3). The existing multivariate models often force the “exchangeable” structure for part or the whole model, are not very flexible which tends to be of limited use in practice. There is a demand for developing and studying multivariate models with any pre-specified bivariate margins.

Suppose there exists such a class of flexible models with any pre-specified bivariate margins. Given a multivariate data, what is the distribution function and how to easily estimate the parameters …

Investigation Of Topological Phonons In Discrete Mechanical Metamaterials, Kai Qian

Dissertations

The study of topological mechanical metamaterials is a new emerging field that focuses on the topological properties of artificial mechanical structures. Inspired by topological insulators, topological mechanism has attracted intensive attention in condensed matter physics and successfully connected the quantum mechanical descriptions of electrons with the classical descriptions of phonons. It has led to experiments of mechanical metamaterials possessing topological characteristics, such as topologically protected conducting edges or surfaces without back-scattering. This dissertation presents a new experimental approach for mechanically engineering topological metamaterials based on patterning magnetically coupled spinners in order to localize the propagation of vibrations and evaluate different …

An Examination Of Fontan Circulation Using Differential Equation Models And Numerical Methods, Vanessa Maybruck

Honors Student Research

Certain congenital heart defects can lead to the development of only a single pumping chamber, or ventricle, in the heart instead of the usual two ventricles. Individuals with this defect undergo a corrective, three-part surgery, the third step of which is the Fontan procedure, but as the patients age, their cardiovascular health will likely deteriorate. Using computational fluid dynamics and differential equations, Fontan circulation can be modeled to investigate why the procedure fails and how Fontan failure can be maximally prevented. Borrowing from well-established literature on RC circuits, the differential equation models simulate systemic blood flow in a piecewise, switch-like …

Towards Improving The Security Of The Software Supply Chain, Hammad Afzali

Dissertations

A software supply chain comprises a series of steps performed to develop and distribute a software product. History has shown that each of these steps is vulnerable to attacks that can have serious repercussions and can affect many users at once. To address the attacks against the software supply chain, end users must be provided with verifiable guarantees about the individual steps of the chain and with assurances that the steps are securely chained together.

In this dissertation, the security of several individual steps in the software supply chain is enhanced. The first step of the chain, managing the source …

Ultralow Velocities Of Caco3 And The Origin Of Seismic Anomalies In The Earth's Upper Mantle, Mingqiang Hou, Ming Hao, Jin Liu, Xiaowan Su, Wen-Yi Zhou, Rostislav Hrubiak, Jin S. Zhang

Earth and Planetary Sciences Faculty and Staff Publications

Calcium carbonate (CaCO₃) is a major host for CO₂ in the deep Earth. The physical and chemical properties of CaCO₃ at extreme pressure-temperature (P-T) conditions are indispensable to decipher the circulation of carbon between the Earth's interior and surface via volcanism and subduction. Using the pulse-echo-overlap method combined with Paris-Edinburgh press, we measured velocities of CaCO₃ and observed an anomalous drop associated with the amorphization of aragonite under upper mantle conditions. The compressional (V_P) and shear (V_S) wave velocities of the partially amorphized CaCO₃ are reduced …

Effects Of Timber Harvest On Epigeous Fungal Fruiting Patterns And Community Structure In A Northern Hardwood Ecosystem, Benjamin W. Borgmann-Winter, Ryan B. Stephens, Anthony W. D'Amato, Serita D. Frey, Rebecca J. Rowe

Faculty Publications

Epigeous fungal fruiting has important impacts on fungal reproduction and ecosystem function. Forest disturbances, such as timber harvest, impact moisture, host availability, and substrate availability, which in turn may drive changes in fungal fruiting patterns and community structure. We surveyed mushrooms in 0.4 ha patch cuts (18 months post-harvest) and adjacent intact hardwood forest in northern New Hampshire, USA, to document the effects of timber harvest on summer fruiting richness, biomass, diversity, and community structure of ectomycorrhizal, parasitic, and saprobic mushroom taxa. Fungal fruiting richness, diversity, and community heterogeneity were greater in intact forests than patch cuts. Among functional groups, …

A Consistent Model Of Terrestrial Planet Magnetospheres And Rotations In Our Solar System, Fred J. Cadieu

Publications and Research

The Sun comprises 99.9% of the solar system mass so it is expected that Sun terrestrial planet interactions can influence the motion as well as the rotation of the terrestrial planets.Gravity affects the planet orbital motions while the changing magnetic fields of the Sun can influence the planet rotations. Planets that manifest a magnetic field dominate any weaker magnetic fields from the Sun, but the rotation of terrestrial planets without a magnetic field interacts with the changing Sun’s field dependent on the electrical conductivity of the core region. It is determined that the average planet density becomes a useful quantity …