Physical Sciences and Mathematics Commons^™

Adapt Virginia: A New Web Portal About Climate Change Adaptations (Www.Adaptva.Org), Center For Coastal Resources Management, Virginia Institute Of Marine Science

Reports

Rivers & Coast is a periodic publication of the Center for Coastal Resources Management, Virginia Institute of Marine Science. The goal of Rivers & Coast is to keep readers well informed of current scientific understanding behind key environmental issues related to watershed rivers and coastal ecosystems of the Chesapeake Bay.

Enhancing Usability And Security Through Alternative Authentication Methods, Nicolas Jorge Van Balen

Dissertations, Theses, and Masters Projects

With the expanding popularity of various Internet services, online users have be- come more vulnerable to malicious attacks as more of their private information is accessible on the Internet. The primary defense protecting private information is user authentication, which currently relies on less than ideal methods such as text passwords and PIN numbers. Alternative methods such as graphical passwords and behavioral biometrics have been proposed, but with too many limitations to replace current methods. However, with enhancements to overcome these limitations and harden existing methods, alternative authentications may become viable for future use. This dissertation aims to enhance the viability …

Disconnected Diagrams In Lattice Qcd, Arjun Singh Gambhir

Dissertations, Theses, and Masters Projects

In this work, we present state-of-the-art numerical methods and their applications for computing a particular class of observables using lattice quantum chromodynamics (Lattice QCD), a discretized version of the fundamental theory of quarks and gluons. These observables require calculating so called "disconnected diagrams" and are important for understanding many aspects of hadron structure, such as the strange content of the proton. We begin by introducing the reader to the key concepts of Lattice QCD and rigorously define the meaning of disconnected diagrams through an example of the Wick contractions of the nucleon. Subsequently, the calculation of observables requiring disconnected diagrams …

Parameterized Process Models For Underwater Munitions Expert System, Carl Friedrichs

Presentations

No abstract provided.

Quantum And Classical Manifestation Of Hamiltonian Monodromy, Chen Chen

Dissertations, Theses, and Masters Projects

Integrable Hamiltonian systems are said to display nontrivial monodromy if fundamental action-angle loops defined on phase-space tori change their topological structure when the system is carried around a circuit. It was shown in earlier work that this topological change can be seen in families of trajectories of noninteracting particles; however, that work required use of a very abstract flow in phase space. In this dissertation, we show that the same topological change can occur as a result of application of ordinary forces. We also show how this dynamical phenomenon could be observed experimentally in cold atom systems. Almost everything that …

Data-Driven Radiometric Photo-Linearization, Han Li

Dissertations, Theses, and Masters Projects

In computer vision and computer graphics, a photograph is often considered a photometric representation of a scene. However, for most camera models, the relation between recorded pixel value and the amount of light received on the sensor is not linear. This non-linear relationship is modeled by the camera response function which maps the scene radiance to the image brightness. This non-linear transformation is unknown, and it can only be recovered via a rigorous radiometric calibration process. Classic radiometric calibration methods typically estimate a camera response function from an exposure stack (i.e., an image sequence captured with different exposures from the …

Deep Learning Software Repositories, Martin White

Dissertations, Theses, and Masters Projects

Bridging the abstraction gap between artifacts and concepts is the essence of software engineering (SE) research problems. SE researchers regularly use machine learning to bridge this gap, but there are three fundamental issues with traditional applications of machine learning in SE research. Traditional applications are too reliant on labeled data. They are too reliant on human intuition, and they are not capable of learning expressive yet efficient internal representations. Ultimately, SE research needs approaches that can automatically learn representations of massive, heterogeneous, datasets in situ, apply the learned features to a particular task and possibly transfer knowledge from task to …

Addressing The Issue Of Microplastics In The Wake Of The Microbead-Free Waters Act - A New Standard Can Facilitate Improved Policy, Jason P. Mcdevitt, Craig S. Criddle, Molly Morse, Robert Hale, Et Al

VIMS Articles

The United States Microbead-Free Waters Act was signed into law in December 2015. It is a bipartisan agreement that will eliminate one preventable source of microplastic pollution in the United States. Still, the bill is criticized for being too limited in scope, and also for discouraging the development of biodegradable alternatives that ultimately are needed to solve the bigger issue of plastics in the environment. Due to a lack of an acknowledged, appropriate standard for environmentally safe microplastics, the bill banned all plastic microbeads in selected cosmetic products. Here, we review the history of the legislation and how it relates …

Measurement Of The Elastic Ep Cross Section At Q2 = 0.66, 1.10, 1.51 And 1.65 Gev2, Yang Wang

Dissertations, Theses, and Masters Projects

The nucleon form factors have been investigated by physicists for decades because of its fundamental importance. The world data of the proton magnetic form factor GMp shows that the measurements have been focused on Q2 lower than 5 GeV2 and it has large uncertainties at higher GeV2. Experiment E12-07-108 aims to improve the accuracy of the e − p elastic cross section to better than 2% over a Q2 range of 7 − 14 GeV2. From 2015 to 2016, the e − p elastic cross section was measured over a wide range of Q2 from 0.66 − 12.56 GeV2 at …

A Global Normal Form For Two-Dimensional Mode Conversion, David Gregory Johnston

Dissertations, Theses, and Masters Projects

Mode conversion is a phenomenon that is of interest as a method for heating in fusion reactors. A magnetosonic wave with dispersion relation DMS propagates toward the interior of the plasma, where it excites an ion-hybrid wave with dispersion relation DIH and thereby transfers energy to the plasma. We wish to study this process using ray-based methods. The 2 2 dispersion matrix D, which is, in general, a function of the phase space variables (x; y; kx; ky), must be put into normal form, in which the diagonals of D, identied as the uncoupled dispersion relations, DMS and DIH, Poisson-commute …

Infrared Spectroscopy And Nano-Imaging Of La0.67sr0.33mno3 Films, Peng Xu

Dissertations, Theses, and Masters Projects

Charge transport properties of manganites can be significantly modified by temperature, chemical doping, strain, and interfacial boundaries. In this dissertation, we report studies on broadband far-field infrared spectroscopy and near-field infrared imaging of single crystalline thin films of Sr doped manganite LaMnO3 at 0.33 doping level. at this Sr-doping level, the manganite films undergo a phase transition between a ferromagnetic metallic phase at low temperatures to a paramagnetic, insulating phase at higher temperatures. The films were grown on different substrates with different thicknesses by pulsed laser deposition method. The temperature dependent far-field infrared data on 85 nm thick La0.67Sr0.33MnO3 (LSMO) …

Flocculation And Bed Consolidation In A Partially Mixed Estuary: An Idealized Numerical Sediment Transport Model, Courtney Harris, D. Tarpley, Carl Friedrichs, C. Sherwood

Presentations

Particle settling velocity and bed erodibility impact the transport of suspended sediment to the first order, but are especially difficult to parameterize for the muds that often dominate estuarine sediments. For example, fine grained silts and clays typically form loosely bound aggregates (flocs) whose settling velocity can vary widely. Properties of flocculated sediment such as settling velocity and particle density are difficult to prescribe because they change in response to several factors, including salinity, suspended sediment concentration, turbulent mixing, organic content, and mineral composition. Additionally, mud consolidates after deposition, so that its erodibility changes over timescales of days to weeks …

Parameterized Process Models For Underwater Munitions Expert System, Carl Friedrichs

Presentations

No abstract provided.

Multifaceted Biodiversity Hotspots Of Marine Mammals For Conservation Priorities, Camille Albouy, Valentine L. Delattre, Bastien Merigot, Christine N. Meynard, Fabien Leprieur

VIMS Articles

Aim: Identifying the multifaceted biodiversity hotspots for marine mammals and their spatial overlap with human threats at the global scale.

A 3d Unstructured-Grid Model For Chesapeake Bay: Importance Of Bathymetry - Supplemental Materials, Fei Ye, Yinglong J. Zhang, Harry V. Wang, Marjorie A.M. Friedrichs, Isaac D. Irby, Arnaldo Valle-Levinson, Zhengui Wang, Hai Huang, Jian Shen, Jiabi Du

Data

No abstract provided.

Virginia Shellfish Aquaculture Situation And Outlook Report : Results Of The 2016 Virginia Shellfish Aquaculture Crop Reporting Survey, Karen Hudson

Reports

The hatchery-based shellfish aquaculture industry in Virginia continues to grow adding significant value to the Commonwealth's seafood marketplace. Today, watermen harvest both hard clams and oysters from the Commonwealth's public resources,albeit at rates diminished from historic levels. At the same time, Virginia's watermen-farmers, utilizing production from a land-based hatchery, are providing additional quantities of quality shellfish to consumers.

This survey, in its 11th year, is intended to continue annual assessments with which to gauge growth and inputs in Virginia's hatchery-based shellfish aquaculture industry. This report is based upon an industry survey completed during the first quarter of 2017.

While these …

Estimation Of Juvenile Striped Bass Relative Abundance In The Virginia Portion Of Chesapeake Bay: Annual Progress Report 2016-2017, Brian K. Gallagher, Mary C. Fabrizio, Troy D. Tuckey

Reports

The 2016 Striped Bass juvenile abundance index was 5.15 and was not significantly different from the reference mean of 7.77 observed in 1980-2009. Abundance indices in the James, York and Rappahannock rivers in 2016 were not significantly different than their historic averages (1967-2015). Juvenile White Perch abundance indices in 2016 were near historic averages in the York and Rappahannock rivers, but below the historic average in the James River. Because a new seine net was used during the 2016 survey, catches of Striped Bass and White Perch were adjusted using preliminary calibration factors derived from paired hauls of the old …

Virginia Game Fish Tagging Program Annual Report 2016, Susanna Musick, Lewis Gillingham

Reports

Through 2016, the Virginia Game Fish Tagging Program (VGFTP) has maintained a 21-year database of records for tagged and recaptured fish. The program is a cooperative project of the Virginia Saltwater Fishing Tournament (VSFT) under the Virginia Marine Resources Commission-(VMRC) and the Virginia Institute of Marine Science (VIMS) of the College of William and Mary (under the VIMS Marine Advisory Program).

Hypoxia Forecasts As A Tool For Chesapeake Bay Fisheries, Marjorie A.M. Friedrichs, A. J. Bever, Carl T. Friedrichs, R.R. Hood

Presentations

No abstract provided.

Plasmonic Approaches And Photoemission: Ag-Based Photocathodes, Zhaozhu Li

Dissertations, Theses, and Masters Projects

Photocathodes play an important role in present large accelerator facilities by providing polarized or un-polarized electron beams. Current state-of-art high polarization photocathodes consist of strained super-lattice GaAs based photocathodes, e.g. GaAs/GaAsP has a quantum efficiency ~1% and polarization ~90% at near-infrared wavelength for the incident light. Despite the advantages offered by metallic photocathodes regarding longer life time, fast response time and low requirements of ultra-high vacuum environment, they have not been put to use due to their low quantum efficiency, even though one can envision several approaches to achieve spin-polarization from them. A possible solution is to apply the Fano …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2016 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the nineteenth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2016, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on a new fishery-independent monitoring program using staked gillnets to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis) in the Rappahannock River. Data are also reported from two separate fishery-independent monitoring …

Measurement Of The Beam Asymmetry Sigma For Pi(0) And Eta Photoproduction On The Proton At E-Gamma=9 Gev, H. Al Ghoul, (...), Justin R. Stevens, Et Al.

Arts & Sciences Articles

We report measurements of the photon beam asymmetry Sigma for the reactions (gamma) over right arrowp -> p pi(0) and gamma p -> p eta from the GLUEX experiment using a 9 GeV linearly polarized, tagged photon beam incident on a liquid hydrogen target in Jefferson Lab's Hall D. The asymmetries, measured as a function of the proton momentum transfer, possess greater precision than previous pi(0) measurements and are the first. measurements in this energy regime. The results are compared with theoretical predictions based on t-channel, quasiparticle exchange and constrain the axial-vector component of the neutral meson production mechanism in …

Isovector Charges Of The Nucleon From 2+1-Flavor Qcd With Clover Fermions, Boram Yoon, Yong-Chull Jang, (...), Kostas Orginos, Et Al.

Arts & Sciences Articles

We present high-statistics estimates of the isovector charges of the nucleon from four 2 + 1-flavor ensembles generated using Wilson-clover fermions with stout smearing and tree-level tadpole improved Symanzik gauge action at lattice spacings a approximate to 0.127 and 0.09 fm and with M-pi approximate to 280 and 170 MeV. The truncated solver method with bias correction and the coherent source sequential propagator construction are used to cost-effectively achieve O (10(5)) measurements on each ensemble. Using these data, the analysis of two-point correlation functions is extended to include four states in the fits, and of three-point functions to three states. …

Kepone In The James River Estuary: Past, Current And Future Trends, Michael A. Unger, George G. Vadas

Reports

In late 1975, a manufacturing facility in Hopewell, VA had not only exposed workers to the chlorinated pesticide, Kepone, but had also severely contaminated the James River estuary. To assess the potential risk to the public, Virginia initiated a finfish-monitoring program in late 1975. Over the next 40 years over 13,000 samples were collected from the James River and Chesapeake Bay and analyzed for Kepone. Kepone production was eventually banned worldwide. The average Kepone concentrations found in most species began falling when the production of Kepone ended, but the averages remained over the action limit of 0.3 mgkg^-1 until …

Stormsense Project: Forecasting Flooding From Storm Surge, Rain, And Tide, Jon Derek Loftis, David R. Forrest, Kyle Spencer

Presentations

The objective of StormSense is to enhance the capability of communities to prepare and respond to the disastrous impacts of sea level rise and coastal flooding in ways that are replicable, scalable, measurable, and make a comparable difference worldwide. The StormSense Project is an inundation forecasting research initiative partially funded by the National Institute of Standards and Technology to advance the field of emergency preparedness for flooding resulting from storm surge, rain, and tides. The scope of the project encompasses the interests of coastal local governments wishing to enhance their emergency preparedness via a network of 'Internet of Things' (IoT)-enabled …

Optical Control Of Multi-Photon Coherent Interactions In Rubidium Atoms, Gleb Vladimirovich Romanov

Dissertations, Theses, and Masters Projects

In the last few decades, coherent light-atom interactions have opened unprecedented possibilities for the coherent control of atomic and optical quantum systems, paved the way for the practical realization of quantum information technologies, and allowed for the creation of novel quantum-enhanced sensors. This dissertation investigates the interaction of multiple near-resonant optical fields with hot rubidium atoms under the conditions of electromagnetically induced transparency. The main goal of the presented research is to address some fundamental challenges in using such systems for practical applications. The EIT effect relies on the strong coupling of an optical probe field and a collective long-lived …

An Investigation Of Power Saving And Privacy Protection On Smartphones, Dachuan Liu

Dissertations, Theses, and Masters Projects

With the advancements in mobile technology, smartphones have become ubiquitous in people's daily lives and have greatly facilitated users in many aspects. For a smartphone user, power saving and privacy protection are two important issues that matter and draw serious attentions from research communities. In this dissertation, we present our studies on some specific issues of power saving and privacy protection on a smartphone. Although IEEE 802.11 standards provide Power Save Mode (PSM) to help mobile devices conserve energy, PSM fails to bring expected benefits in many real scenarios. We define an energy conserving model to describe the general PSM …

Enhancing Energy Efficiency And Privacy Protection Of Smart Devices, Ge Peng

Dissertations, Theses, and Masters Projects

Smart devices are experiencing rapid development and great popularity. Various smart products available nowadays have largely enriched people’s lives. While users are enjoying their smart devices, there are two major user concerns: energy efficiency and privacy protection. In this dissertation, we propose solutions to enhance energy efficiency and privacy protection on smart devices. First, we study different ways to handle WiFi broadcast frames during smartphone suspend mode. We reveal the dilemma of existing methods: either receive all of them suffering high power consumption, or receive none of them sacrificing functionalities. to address the dilemma, we propose Software Broadcast Filter (SBF). …

Climate Change Impacts On Southern Ross Sea Phytoplankton Composition, Productivity, And Export, Daniel E. Kaufman, Marjorie A. M. Friedrichs, Walker O. Smith Jr., Eileen E. Hofmann, Michael S. Dinniman, John C. P. Hemmings

VIMS Articles

The Ross Sea, a highly productive region of the Southern Ocean, is expected to experience warming during the next century along with reduced summer sea ice concentrations and shallower mixed layers. This study investigates how these climatic changes may alter phytoplankton assemblage composition, primary productivity, and export. Glider measurements are used to force a one-dimensional biogeochemical model, which includes diatoms and both solitary and colonial forms of Phaeocystis antarctica. Model performance is evaluated with glider observations, and experiments are conducted using projections of physical drivers for mid-21st and late-21st century. These scenarios reveal a 5% increase in primary productivity …

Estimating Relative Abundance Of Young-Of-The-Year American Eel, Anguilla Rostrata, In The Virginia Tributaries Of Chesapeake Bay, Spring 2016, Mary C. Fabrizio, Troy D. Tuckey

Reports

American Eel (Anguilla rostrata) is a valuable commercial species along the Atlantic coast of North America from New Brunswick to Florida. In the U.S., harvests have declined, with similar patterns occurring in the Canadian Maritime Provinces (Meister and Flagg 1997). An average of 62% of the annual landings of U.S. commercial harvest since 1993 have come from the Chesapeake Bay (personal communication from the National Marine Fisheries Service, Fisheries Statistics Division, 9 February 2015). In 2013, Virginia commercial landings were approximately 100,298 lbs; since mandatory reporting began in 1993, average annual landings in Virginia have been 193,200 lbs or 19% …