Physical Sciences and Mathematics Commons^™

Modern Pyromes: Biogeographical Patterns Of Fire Characteristics Across The Contiguous United States, Megan E. Cattau, Adam Mahood, Jennifer K. Balch, Carol Wessman

Human-Environment Systems Research Center Faculty Publications and Presentations

In recent decades, wildfires in many areas of the United States (U.S.) have become larger and more frequent with increasing anthropogenic pressure, including interactions between climate, land-use change, and human ignitions. We aimed to characterize the spatiotemporal patterns of contemporary fire characteristics across the contiguous United States (CONUS). We derived fire variables based on frequency, fire radiative power (FRP), event size, burned area, and season length from satellite-derived fire products and a government records database on a 50 km grid (1984–2020). We used k-means clustering to create a hierarchical classification scheme of areas with relatively homogeneous fire characteristics, or modern …

Perspectives On Living Shorelines: Marine Contractors And Agents In Southeast Virginia, Michelle Covi, Juita-Elena (Wie) Yusuf

Presentations, Lectures, Posters, Reports

No abstract provided.

Land Use/ Land Cover Change Patterns And Trends In Two Dryland Regions, Omar Sulaiman Belhaj

Open Access Theses & Dissertations

Development and climate change affect the environment in numerous ways and to varyingdegrees. This effect appears prominent and more influential in arid regions. Therefore, land use/ land cover in these regions experience profound changes such as plant cover decrease and extinction of some plant species. Also, land use/ land cover in these regions has critical impacts on the environment and its components, such as shrublands shrinking and losing the habitat of animal species. The degree of changes and effects reaches severe levels that become urgent to figure out the impacts and find solutions to stop or mitigate the negative consequences. …

Efficient Approaches To Steady State Detection In Multivariate Systems, Honglun Xu

Open Access Theses & Dissertations

Steady state detection is critically important in many engineering fields such as fault detection and diagnosis, process monitoring and control. However, most of the existing methods are designed for univariate signals. In this dissertation, we proposed an efficient online steady state detection method for multivariate systems through a sequential Bayesian partitioning approach. The signal is modeled by a Bayesian piecewise constant mean and covariance model, and a recursive updating method is developed to calculate the posterior distributions analytically. The duration of the current segment is utilized to test the steady state. Insightful guidance is provided for hyperparameter selection. The effectiveness …

2022 August - Tennessee Monthly Climate Report, Tennessee Climate Office, East Tennessee State University

Tennessee Climate Office Monthly Reports

No abstract provided.

The Tess Grand Unified Hot Jupiter Survey. I. Ten Tess Planets, S. W. Yee, J. N. Winn, J. D. Hartman, J. E. Rodriguez, G. Zhou, S. N. Quinn, D. W. Latham, A. Bieryla, K. A. Collins, B. C. Addison, I. Angelo, K. Barkaoui, P. Benni, A. W. Boyle, R. Brahm, R. P. Butler, D. R. Ciardi, K. I. Collins, D. M. Conti, J. D. Crane, F. Dai, C. D. Dressing, J. D. Eastman, Z. Essack, R. Forés-Toribio, E. Furlan, T. Gan, S. Giacalone, H. Gill, E. Girardin, T. Henning, C. E. Henze, M. J. Hobson, J. Horner, A. W. Howard, S. B. Howell, C. X. Huang, H. Isaacson, J. M. Jenkins, Eric L.N. Jensen, A. Jordán, S. R. Kane, J. F. Kielkopf, S. Lasota, A. M. Levine, J. Lubin, A. W. Mann, B. Massey, K. K. Mcleod, M. W. Mengel, J. A. Muñoz, F. Murgas, E. Palle, P. Plavchan, A. Popowicz, D. J. Radford, G. R. Ricker, P. Rowden, B. S. Safonov, A. B. Savel, R. P. Schwarz, S. Seager, R. Sefako, A. Shporer, G. Srdoc, I. S. Strakhov, J. K. Teske, C. G. Tinney, D. Tyler, R. A. Wittenmyer, H. Zhang, C. Ziegler

Physics & Astronomy Faculty Works

Hot Jupiters—short-period giant planets—were the first extrasolar planets to be discovered, but many questions about their origin remain. NASA's Transiting Exoplanet Survey Satellite (TESS), an all-sky search for transiting planets, presents an opportunity to address these questions by constructing a uniform sample of hot Jupiters for demographic study through new detections and unifying the work of previous ground-based transit surveys. As the first results of an effort to build this large sample of planets, we report here the discovery of 10 new hot Jupiters (TOI-2193A b, TOI-2207b, TOI-2236b, TOI-2421b, TOI-2567b, TOI-2570b, TOI-3331b, TOI-3540A b, TOI-3693b, TOI-4137b). All of the planets …

Replication Data For: Investigating Detection Probability Of Mobile Survey Solutions For Natural Gas Pipeline Leaks Under Different Atmospheric Conditions, Shanru Tian, Stuart Riddick, Younki Cho, Clay Bell, Daniel Zimmerle, Kathleen Smits

Earth & Environmental Sciences Datasets - Archive

The 2015 Paris agreement aims to cut greenhouse gas emissions and keep global temperature rise below 2 °C above pre-industrial levels. Reducing CH4 emissions from leaking pipelines presents a relatively achievable objective. While walking and driving surveys are commonly used to detect leaks, the detection probability (DP) is poorly characterized. This study aims to investigate how leak rates, survey distance and speed, and atmospheric conditions affect the DP in controlled belowground conditions with release rates of 0.5–8.5 g min−1. Results show that DP is highly influenced by survey speed, atmospheric stability, and wind speed. The average DP in Pasquill–Gifford stability …

Synthetic Studies On Oxidative Dearomatization Reactions And Applications In Synthesis Of The Kb343 Core Structure, And Investigation Of Bioactive Thiazolidines, Marian Awadalla

Chemistry & Biochemistry Dissertations - Archive

Natural products have inspired researchers over the years due to their complexity and biological activity. Organic chemists have made great efforts to investigate new unambiguous methodologies toward the synthesis of these complex structures. Moreover, the synergy between total chemical synthesis and medicinal applications to evaluate the biological activity of the isolated compounds significantly raised the desire for discovery of novel synthetic approaches. The research described in this dissertation focuses on oxidative dearomatization reactions as a key reaction to construct natural products. The three specific aims are as follows: Aim 1: investigation of the applications of oxidative dearomatization reactions for different …

Towards A Low-Cost Solution For Gait Analysis Using Millimeter Wave Sensor And Machine Learning, Mubarak A. Alanazi, Abdullah K. Alhazmi, Osama Alsattam, Kara Gnau, Meghan Brown, Shannon Thiel, Kurt Jackson, Vamsy P. Chodavarapu

Electrical and Computer Engineering Faculty Publications

Human Activity Recognition (HAR) that includes gait analysis may be useful for various rehabilitation and telemonitoring applications. Current gait analysis methods, such as wearables or cameras, have privacy and operational constraints, especially when used with older adults. Millimeter-Wave (MMW) radar is a promising solution for gait applications because of its low-cost, better privacy, and resilience to ambient light and climate conditions. This paper presents a novel human gait analysis method that combines the micro-Doppler spectrogram and skeletal pose estimation using MMW radar for HAR. In our approach, we used the Texas Instruments IWR6843ISK-ODS MMW radar to obtain the micro-Doppler spectrogram …

Using Coherence And Interference To Study The Few Body Dynamics In Simple Atomic Collisions Systems, Sujan Bastola

Doctoral Dissertations

"Atomic Collision experiments are best suited to sensitively test the few-body dynamics of simple systems. The few-body dynamics, in turn, can be sensitively affected by interference effects. However, an important requirement to observe interference effects in atomic scattering experiments is that the incoming projectile beam must be coherent. The coherence properties of the incoming projectile can be controlled by the geometry of the collimating slit placed before the target. We performed a kinematically complete experiment where a 75 keV proton beam is crossed with a molecular hydrogen beam to study the dissociative capture process. The motivation for this project was …

Survivor Bond Models For Securitizing Longevity Risk, Priscilla Mansah Codjoe

Doctoral Dissertations

"Longevity risk is the risk that a reference population’s mortality rates deviate from what is projected from prior life tables. This is due to discoveries in biological sciences, improved public health measures, and nutrition, which have dramatically increased life expectancy. Longevity risk raises life insurers’ liability, increasing product costs and reserves. Securitization through longevity derivatives is a way of dealing with this risk.

To enhance the pricing of life contingent products, we present an additive type mortality model in the style of the Lee-Carter. This model incorporates policyholder covariates. By using counting processes and martingale machinery, we obtain close form …

Hydroclimate Variability In Central America During The Holocene Inferred From Lacustrine Sediments In Lake Izabal, Eastern Guatemala, Edward Fernando Duarte

Doctoral Dissertations

"Holocene hydroclimate reconstructions have contributed to our understanding of the mechanisms controlling precipitation in Central America. Recent hydroclimate proxy records from the region, however, have revealed considerable spatiotemporal complexity in precipitation variability. This complexity is hypothesized to result from the interaction between multiple oceanic-atmospheric processes that converge in the region. This project analyzed three sediment cores from Lake Izabal, eastern lowland Guatemala, with the goal of understanding changes in precipitation, lake productivity, and lake water chemistry during the Holocene. Our proxy results indicate that precipitation in the region increased from the early to the middle Holocene, when Lake Izabal became …

Social Media Analytics With Applications In Disaster Management And Covid-19 Events, Md Yasin Kabir

Doctoral Dissertations

"Social media such as Twitter offers a tremendous amount of data throughout an event or a disastrous situation. Leveraging social media data during a disaster is beneficial for effective and efficient disaster management. Information extraction, trend identification, and determining public reactions might help in the future disaster or even avert such an event. However, during a disaster situation, a robust system is required that can be deployed faster and process relevant information with satisfactory performance in real-time. This work outlines the research contributions toward developing such an effective system for disaster management, where it is paramount to develop automated machine-enabled …

Secured Information Dissemination And Misbehavior Detection In Vanets, Ayan Roy

Doctoral Dissertations

"In a connected vehicle environment, the vehicles in a region can form a distributed network (Vehicular Ad-hoc Network or VANETs) where they can share traffic-related information such as congestion or no-congestion with other vehicles within its proximity, or with a centralized entity via. the roadside units (RSUs). However, false or fabricated information injected by an attacker (or a malicious vehicle) within the network can disrupt the decision-making process of surrounding vehicles or any traffic-monitoring system. Since in VANETs the size of the distributed network constituting the vehicles can be small, it is not difficult for an attacker to propagate an …

Minimal Differential Graded Algebra Resolutions Related To Certain Stanley-Reisner Rings, Todd Anthony Morra

All Dissertations

We investigate algebra structures on resolutions of a special class of Cohen-Macaulay simplicial complexes. Given a simplicial complex, we define a pure simplicial complex called the purification. These complexes arise as a generalization of certain independence complexes and the resultant Stanley-Reisner rings have numerous desirable properties, e.g., they are Cohen-Macaulay. By realizing the purification in the context of work of D'alì, et al., we obtain a multi-graded, minimal free resolution of the Alexander dual ideal of the Stanley-Reisner ideal. We augment this in a standard way to obtain a resolution of the quotient ring, which is likewise minimal and multi-graded. …

Understanding Dynamics Of Polymers Under Confinement: A Molecular Dynamics And Neutron Scattering Study, Supun Samindra Kamkanam Mohottalalage

All Dissertations

The current study probes the structure, dynamics, and rheological behavior of associating polymers including ionomers in melts and solutions as well as conjugated polymers confined into nanoparticles, using molecular dynamics (MD) simulations and neutron scattering techniques. The study focuses on two families of associative polymers, ion containing macromolecules and conjugated polymers.

Polymers that consist of ionizable groups along their backbone found uses in a broad range of applications. Examples include light weight energy storage and generation systems, and biomedical applications, where the polymers act as ion exchange membranes, and actuators. The ionic groups tend to form clusters that are in …

Characteristics And Health Effects Of Particulate Matter Emitted From A Waste Sorting Plant, Abdullah Barkhordari, Marcelo I. Guzman, Gholamreza Ebrahimzadeh, Armin Sorooshian, Mahdieh Delikhoon, Mehdi Jamshidi Rastani, Somayeh Golbaz, Mehdi Fazlzadeh, Ramin Nabizadeh, Abbas Norouzian Baghani

Chemistry Faculty Publications

Solid waste components can be recycled in waste paper and cardboard sorting plants (WPCSP) through a multistep process. This work collected 15 samples every six days from each of the 9 points selected to study the processes taking place in a WPCSP (135 particulate matter samples total). Examining the concentration and size fraction of particulate matter (i.e., PM1, PM2.5 and PM10) in WPCSP is an essential issue to notify policy makers about the health impacts on exposed workers. The major activities for increasing of the concentration of PM in various processing units in the WPCSP, especially in hand-picking routes I …

Glaciernet2: A Hybrid Multi-Model Learning Architecture For Alpine Glacier Mapping, Zhiyuan Xie, Umesh K. Haritashya, Vijayan K. Asari, Michael P. Bishop, Jeffrey S. Kargel, Theus Aspiras

Electrical and Computer Engineering Faculty Publications

In recent decades, climate change has significantly affected glacier dynamics, resulting in mass loss and an increased risk of glacier-related hazards including supraglacial and proglacial lake development, as well as catastrophic outburst flooding. Rapidly changing conditions dictate the need for continuous and detailed ob-servations and analysis of climate-glacier dynamics. Thematic and quantitative information regarding glacier geometry is fundamental for understanding climate forcing and the sensitivity of glaciers to climate change, however, accurately mapping debris-cover glaciers (DCGs) is notoriously difficult based upon the use of spectral information and conventional machine-learning techniques. The objective of this research is to improve upon an …

Impact Of Adding Natural And Simulated Root Exudates On The Functioning Of Contaminated Soil, Bhagyashree P. Vaidya

Theses, Dissertations and Culminating Projects

No abstract provided.

The Effects And Costs Of Changes In River Flooding In New Jersey, Yousef Alagrabawi

Theses, Dissertations and Culminating Projects

The purpose of this research is to quantify the flood risks of rivers in various locations in New Jersey and how they have changed over time. This is important because the change is likely to continue over time as climate change continues. ArcGIS, HEC-SSP, and online sources such as Trulia (www.trulia.com) were used to understand where flooding is most likely to occur, which streets, and how many homes will be affected and estimate the cost of damages from a potential 100-year flood. I compiled information such as annual peak river discharge from the USGS river gages on the Delaware River …

Calculational Methods In Conformal Field Theory, Thomas Andrew Vandermeulen

Legacy Theses & Dissertations (2009 - 2024)

We examine conformal field theories and their gaugings (orbifolds), first on the torus and then on surfaces of higher genus. Specific attention is paid to performing explicit calculations, to which end we introduce a number of specialized formalisms. Namely, the technology of flavored partition functions allows for a general treatment of orbifolds in theories with conserved currents, and Arakelov geometry facilitates the derivation of novel expressions for geometric quantities appearing commonly on higher genus worldsheets. Ultimately, we leverage the resulting expressions in the calculation of correlation functions via degeneration of Riemann surfaces.

Computational Methods For Propagation Of Optical Fields With The Angle-Impact Wigner Function, Jeremy Wittkopp

Legacy Theses & Dissertations (2009 - 2024)

In designing an optical setup for an experiment, one usually turns to simulations first in order to model the propagation of light through the proposed system. This way, the experimenter can determine if the system is operating as intended. In order for these simulations to be useful, they need to properly describe the propagation of light. In order to simplify calculations, most contemporary software makes assumptions on the nature of the light being propagated. Specifically, simulations typically consider optical fields that are beam-like (i.e., most of the rays comprising the field deviate only slightly in angle from the beam's primary …

Amyloid Fibril Formation And Polymorphism : A Critical Role Of Sulfur-Containing Amino Acid Residues, Tatiana Quiñones-Ruiz

Legacy Theses & Dissertations (2009 - 2024)

Protein aggregation that results in the formation of amyloid fibrils has been linked to many neurodegenerative disorders, including Alzheimer’s disease and Parkinson’s disease. The sulfur atoms in methionine (Met) and cysteine (Cys) residues of proteins can be readily oxidized, significantly affecting their properties. Oxidation of sulfur-containing amino acids has recently been shown to affect protein fibrillation. This work presents novel findings on Cys and Met redox reactions that are related to the formation of amyloid fibrils and on the polymorphism of a model fibrillogenic protein, hen egg white lysozyme (HEWL). Biophysical techniques including Raman spectroscopy, atomic force microscopy, electron paramagnetic …

Examining The Impact Of Stratospheric Vortex Variability On Us Surface Temperature, Elena M. Fernandez

Legacy Theses & Dissertations (2009 - 2024)

Variability in high-latitude stratospheric flow, including major sudden stratospheric warming (SSW) or strong polar vortex events, can modulate tropospheric circulation and have meteorological implications on surface temperature and weather. The largest tropospheric impacts from Northern Hemisphere stratospheric variability – and the regions of focus in the literature – are observed in the North Atlantic, Europe and Asia. Impacts on North America occur but have received less research attention. The goal of this thesis research is to identify and quantify the relationship between high-latitude stratospheric variability and North American wintertime temperature.Using the ERA-Interim and ERA-5 reanalysis for the period of 1999/2000–2018/19, …

Presto : Fast And Effective Group Closeness Maximization, Baibhav L. Rajbhandari

Legacy Theses & Dissertations (2009 - 2024)

Given a graph and an integer k, the goal of group closeness maximization is to find, among all possible sets of k vertices (called seed sets), a set that has the highest group closeness centrality. Existing techniques for this NP-hard problem strive to quickly find a seed set with a high, but not necessarily the highest centrality.

An Ims-Ms/Md Workflow For Determining Higher Order Structure And Dynamics Of Nucleic Acids, Rebecca D'Esposito

Legacy Theses & Dissertations (2009 - 2024)

Ion mobility spectrometry - mass spectrometry (IMS-MS) has potential for the investigation of structure and dynamics in large biopolymers, which will come to full fruition only with a firmer understanding of how to interpret the experimental data. Numerous studies have employed elements of nucleic acid (NA) secondary structure, such as duplexes and hairpins, to explore the relationships between structure, experimental conditions, and actual observations. When combined with molecular dynamics simulations (MDS), IMS-MS can be effectively employed to perform structural elucidation of biomolecules that are not readily amenable to established techniques employed for structural analysis.

Deep Active Genetic Learning With Evidential Uncertainty For Agriculture Crops And Lake Water Quality Assessment, Oguz M. Aranay

Legacy Theses & Dissertations (2009 - 2024)

Despite significant advancements in the field of machine learning, there are two issues that still require further exploration. First, how to learn from a small dataset; and second, how to select appropriate features from the data. Although there exist many techniques to address these issues, choosing a combination of the techniques from these two groups is challenging, and worth investigating. To address these concerns, this thesis presents a learning framework that is based on a deep learning model utilizing active learning (with evidential uncertainty as a basis for acquisition function) for the first issue and a genetic algorithm for the …

Frameworks For Secure Collaborative And Concurrent Editing, Shashank Arora

Legacy Theses & Dissertations (2009 - 2024)

Cloud-based online document editing services, such as Google Docs and Office 365, provide an inexpensive and efficient means of managing documents. However, storing data on the cloud also raises certain security and privacy concerns, especially when the data is of confidential and sensitive nature. Storing data on third-party servers can potentially be compromising as it gives an opportunity to the third-party cloud service providers to turn semi-honest and become curious about user data. User data stored on third-party servers is also prone to attacks like virtual machine-based side-channel along with natural language processing and machine learning-based content search and retrieval …

A Comparative Analysis Of The Impact Of Low-Level Jets And Atmospheric Rivers In The Central U.S, Nabindra Gyawali

Legacy Theses & Dissertations (2009 - 2024)

Atmospheric Rivers (AR) are the primary source of poleward moisture transport globally. In theUnited States, much recent attention has been placed on Pacific Coast ARs which occur between December and March. However, the central US is also substantially impacted by warm-season AR. An open question is whether these warm-season ARs are synonymous with Great Plains low-level jets (LLJs) that have long served as a focal point of mesoscale atmospheric research. In this study, we perform a comparative analysis of ARs and LLJs in the central U.S using ECMWF’s climate-quality reanalysis of the 20th century, CERA-20C. The aim is to identify …

Stability And Differential Privacy Of Stochastic Gradient Methods, Zhenhuan Yang

Legacy Theses & Dissertations (2009 - 2024)

Recently there are a considerable amount of work devoted to the study of the algorithmic stability as well as differential privacy (DP) for stochastic gradient methods (SGM). However, most of the existing work focus on the empirical risk minimization (ERM) and the population risk minimization problems. In this paper, we study two types of optimization problems that enjoy wide applications in modern machine learning, namely the minimax problem and the pairwise learning problem.