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Full-Text Articles in Physical Sciences and Mathematics

Developing Efficient High-Order Transport Schemes For Cross-Scale Coupled Estuary-Ocean Modeling, Fei Ye Jan 2018

Developing Efficient High-Order Transport Schemes For Cross-Scale Coupled Estuary-Ocean Modeling, Fei Ye

Dissertations, Theses, and Masters Projects

Geophysical fluid dynamics (GFD) models have progressed greatly in simulating the world’s oceans and estuaries in the past three decades, thanks to the development of novel numerical algorithms and the advent of massively parallel high-performance computing platforms. Study of inter-related processes on multi-scales (e.g., between large-scale (remote) processes and small-scale (local) processes) has always been an important theme for GFD modeling. For this purpose, models based on unstructured-grid (UG) have shown great potential because of their superior abilities in enabling multi-resolution and in fitting geometry and boundary. Despite UG models’ successful applications on coastal systems, significant obstacles still exist that …


The Development And Proliferation Of Summer Algal Blooms In The Oligo/Poly-Haline Portion Of The Chesapeake Bay - Observational And Numerical Modeling Studies, Zhengui Wang Jan 2018

The Development And Proliferation Of Summer Algal Blooms In The Oligo/Poly-Haline Portion Of The Chesapeake Bay - Observational And Numerical Modeling Studies, Zhengui Wang

Dissertations, Theses, and Masters Projects

Algal blooms occur annually in many parts of the Chesapeake Bay. The causes of algal blooms are complex and can be different in different regions. In this study, we will conduct data analysis for the observed data and adopt various methods to investigate algal bloom phenomenon in three separate regions in the oligo/poly-haline portion of the Bay. Chapter 1 provides a general introduction of the algal bloom research in the Chesapeake Bay. In Chapter 2, an observational analysis and a numerical study on the algal blooms in Back River were conducted. A hypothesis was made that high pH can trigger …


Characterizing The Biological Impacts And Human Dimensions Of The U.S. East Coast Recreational Atlantic Bluefin Tuna Fishery, William Morris Goldsmith Jan 2018

Characterizing The Biological Impacts And Human Dimensions Of The U.S. East Coast Recreational Atlantic Bluefin Tuna Fishery, William Morris Goldsmith

Dissertations, Theses, and Masters Projects

Atlantic bluefin tuna (Thunnus thynnus) are targeted by recreational anglers along the east coast of the United States, and the fishery is thought to be of considerable economic value. However, limited knowledge of the preferences and values of fishery participants impedes the ability of managers to maximize fishery benefits and predict harvest patterns, while an incomplete understanding of post-release mortality hinders efforts to estimate total mortality resulting from the fishery. This dissertation used a multidisciplinary approach that relied heavily on cooperative research with the recreational fishing community to examine these questions. A stated choice survey of private anglers permitted to …


Enhancing Usability, Security, And Performance In Mobile Computing, Shanhe Yi Jan 2018

Enhancing Usability, Security, And Performance In Mobile Computing, Shanhe Yi

Dissertations, Theses, and Masters Projects

We have witnessed the prevalence of smart devices in every aspect of human life. However, the ever-growing smart devices present significant challenges in terms of usability, security, and performance. First, we need to design new interfaces to improve the device usability which has been neglected during the rapid shift from hand-held mobile devices to wearables. Second, we need to protect smart devices with abundant private data against unauthorized users. Last, new applications with compute-intensive tasks demand the integration of emerging mobile backend infrastructure. This dissertation focuses on addressing these challenges. First, we present GlassGesture, a system that improves the usability …


Assessing The Impact Of Land Use And Climate Change On Streamflow And Nutrient Delivery To The New River Estuary, Nc, Shanna Williamson Jan 2018

Assessing The Impact Of Land Use And Climate Change On Streamflow And Nutrient Delivery To The New River Estuary, Nc, Shanna Williamson

Dissertations, Theses, and Masters Projects

Freshwater inflow influences numerous physical, chemical, and biological characteristics of estuaries. The influx of freshwater to an estuary typically serves as an important source of allochthonous material from which primary producers derive their energy and transfer this energy to higher trophic levels. Any changes to freshwater flow subsequently impacts nutrient delivery and indirectly impacts organisms across multiple trophic levels. Anthropogenic changes to coastal land use and climate both act to threaten the integrity of estuarine systems by influencing freshwater inflow and dissolved nutrient input. Watershed loading models such as the Regional Nutrient Management (ReNuMa) model offer the ability to estimate …


Mixed-Weight Open Locating-Dominating Sets, Robin M. Givens Jan 2018

Mixed-Weight Open Locating-Dominating Sets, Robin M. Givens

Dissertations, Theses, and Masters Projects

The detection and location of issues in a network is a common problem encompassing a wide variety of research areas. Location-detection problems have been studied for wireless sensor networks and environmental monitoring, microprocessor fault detection, public utility contamination, and finding intruders in buildings. Modeling these systems as a graph, we want to find the smallest subset of nodes that, when sensors are placed at those locations, can detect and locate any anomalies that arise. One type of set that solves this problem is the open locating-dominating set (OLD-set), a set of nodes that forms a unique and nonempty neighborhood with …


Charge Dynamics In The Metallic And Superconducting States Of The Electron-Doped 122-Type Iron Arsenides, Zhen Xing Jan 2018

Charge Dynamics In The Metallic And Superconducting States Of The Electron-Doped 122-Type Iron Arsenides, Zhen Xing

Dissertations, Theses, and Masters Projects

Understanding charge dynamics and the origin of superconductivity in iron-based materials is one of the most important topics in condensed matter physics. Among different structures of iron-based materials, 122-type iron arsenides are of considerable interest due to their diverse phase diagrams, relatively high superconducting transition temperatures, and the availability of high quality single crystals. In this dissertation, we study temperature and frequency dependence of charge dynamics of the electron-doped 122-type iron arsenides in the metallic and superconducting states using broadband infrared spectroscopy at cryogenic temperatures. We have investigated the charge dynamics and the nature of many-body interactions in metallic La- …


Improving Stock Assessments And Management Advice For Bluefin Tunas And Other Highly Migratory Species, Lisa Elma Ailloud Jan 2018

Improving Stock Assessments And Management Advice For Bluefin Tunas And Other Highly Migratory Species, Lisa Elma Ailloud

Dissertations, Theses, and Masters Projects

For years bluefin tuna has been the poster child for overfishing and poor management. However, recent improvements in data collection, catch monitoring and international cooperation are providing an opportunity to reverse the perception of a fishery that is doomed to collapse. Stock assessments are conducted routinely to monitor the abundance and productivity of exploited fish stocks so managers can determine how many fish can be sustainably harvested each year. Should a stock be declared overfished or under-going overfishing, the science behind stock assessments also equip managers with the knowledge necessary to make decisions about what short-term and long-term management measures …


Automating Software Development For Mobile Computing Platforms, Kevin Patrick Moran Jan 2018

Automating Software Development For Mobile Computing Platforms, Kevin Patrick Moran

Dissertations, Theses, and Masters Projects

Mobile devices such as smartphones and tablets have become ubiquitous in today's computing landscape. These devices have ushered in entirely new populations of users, and mobile operating systems are now outpacing more traditional "desktop" systems in terms of market share. The applications that run on these mobile devices (often referred to as "apps") have become a primary means of computing for millions of users and, as such, have garnered immense developer interest. These apps allow for unique, personal software experiences through touch-based UIs and a complex assortment of sensors. However, designing and implementing high quality mobile apps can be a …


Lattice Qcd For Neutrinoless Double Beta Decay: Short Range Operator Contributions, Henry Jose Monge Camacho Jan 2018

Lattice Qcd For Neutrinoless Double Beta Decay: Short Range Operator Contributions, Henry Jose Monge Camacho

Dissertations, Theses, and Masters Projects

The Standard Model (SM), the fundamental theory of particle physics, very success- fully describes the world around us, and with a only a few tantalizing exceptions, all the experiments we have performed to understand the fundamental laws of nature. However, the SM accounts for only 4-5% of the matter and energy in the universe, with approxi- mately 25% composed of dark matter (DM) and the remaining 70% composed of the more mysterious dark energy. Further, the SM content of the universe is composed of an excess of matter over anti-matter of about 1 part per billion. Despite being a small …


Impacts Of Atmospheric Nitrogen Deposition And Coastal Nitrogen Fluxes On Chesapeake Bay Hypoxia, Fei Da Jan 2018

Impacts Of Atmospheric Nitrogen Deposition And Coastal Nitrogen Fluxes On Chesapeake Bay Hypoxia, Fei Da

Dissertations, Theses, and Masters Projects

Although rivers are the primary source of dissolved inorganic nitrogen (DIN) inputs to the Chesapeake Bay, direct atmospheric DIN deposition and DIN fluxes from the continental shelf can also significantly impact Chesapeake Bay hypoxia. The relative role of these additional sources of DIN has not previously been thoroughly quantified. In this study, the three-dimensional Estuarine-Carbon-Biogeochemistry model embedded in the Regional Ocean Modeling System (ChesROMS-ECB) is used to examine the relative impact of these three DIN sources. Model simulations highlight that DIN inputs from the atmosphere have roughly the same impact on hypoxia as the same gram for gram change in …