Physical Sciences and Mathematics Commons^™

A Dynamic Ocean Management Tool To Reduce Bycatch And Support Sustainable Fisheries, Elliot L. Hazen, Kylie L. Scales, Sara M. Maxwell, Dana K. Briscoe, Heather Welch, Steven J. Bograd, Helen Bailey, Scott R. Benson, Tomo Eguchi, Heidi Dewar

Biological Sciences Faculty Publications

Seafood is anessential sourceofprotein formore than3billionpeopleworldwide, yet bycatchof threatened species in capture fisheries remains a major impediment to fisheries sustainability. Management measures designed to reduce bycatch often result in significant economic losses and even fisheries closures. Static spatial management approaches can also be rendered ineffective by environmental variability and climate change, as productive habitats shift and introduce new interactions between human activities and protected species. We introduce a new multispecies and dynamic approach that uses daily satellite data to track ocean features and aligns scales of management, species movement, and fisheries. To accomplish this, we create species distribution models for …

Integrating Dynamic Subsurface Habitat Metrics Into Species Distribution Models, Stephanie Brodie, Michael G. Jacox, Steven J. Bograd, Heather Welch, Heidi Dewar, Kylie L. Scales, Sara M. Maxwell, Dana M. Briscoe, Christopher A. Edwards, Larry B. Crowder, Rebecca L. Lewison, Elliott L. Hazen

Biological Sciences Faculty Publications

Species distribution models (SDMs) have become key tools for describing and predicting species habitats. In the marine domain, environmental data used in modeling species distributions are often remotely sensed, and as such have limited capacity for interpreting the vertical structure of the water column, or are sampled in situ, offering minimal spatial and temporal coverage. Advances in ocean models have improved our capacity to explore subsurface ocean features, yet there has been limited integration of such features in SDMs. Using output from a data-assimilative configuration of the Regional Ocean Modeling System, we examine the effect of including dynamic subsurface …

New Dimensions For A Challenging Security Environment: Growing Exposure To Critical Space Infrastructure Disruption Risk, Adrian V. Gheorghe, Alexandru Georgescu, Olga Bucovetchi, Marilena Lazăr, Cezar Scarlat

Engineering Management & Systems Engineering Faculty Publications

Space systems have become a key enabler for a wide variety of applications that are vital to the functioning of advanced societies. The trend is one of quantitative and qualitative increase of this dependence, so much so that space systems have been described as a new example of critical infrastructure. This article argues that the existence of critical space infrastructures implies the emergence of a new category of disasters related to disruption risks. We inventory those risks and make policy recommendations for what is, ultimately, a resilience governance issue.

Research Agenda In Developing Core Reference Ontology For Human Intelligence/Machine-Intelligence Electronic Medical Records System, Ziniya Zahedi, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

Beginning around 1990, efforts were initiated in the medical profession by the U.S. government to transition from paper based medical records to electronic medical records (EMR). By the late 1990s, EMR implementation had already encountered multiple barriers and failures. Then President Bush set forth the goal of implementing electronic health records (EHRs), nationwide within ten years. Again, progress toward EMR implementation was not realized. President Obama put new emphasis on promoting EMR and health care technology. The renewed emphasis did not overcome many of the original problems and induced new failures. Retrospective analyses suggest that failures were induced because programmers …

A Proposed Taxonomy For The Systems Statistical Engineering Body Of Knowledge, Teddy Steven Cotter

Engineering Management & Systems Engineering Faculty Publications

In the ASEM-IAC 2012, Cotter (2012) identified the gaps in knowledge that statistical engineering needs to address, explored additional gaps in knowledge not addressed in the prior works, and set forth a working definition of and body of knowledge for statistical engineering. In the ASEM-IAC 2015, Cotter (2015) proposed a systemic causal Bayesian hierarchical model that addressed the knowledge gap needed to integrate deterministic mathematical engineering causal models within a stochastic framework. Missing, however, is the framework for specifying the hierarchical qualitative systems structures necessary and sufficient for specifying systemic causal Bayesian hierarchical models. In the ASEM-IAC 2016, Cotter (2016) …

An Attribute Agreement Method For Hfacs Inter-Rater Reliability Assessment, Teddy Steven Cotter, Veysel Yesilbas

Engineering Management & Systems Engineering Faculty Publications

Inter-rater reliability can be regarded as the degree of agreement among raters on a given item or a circumstance. Multiple approaches have been taken to estimate and improve inter-rater reliability of the United States Department of Defense Human Factors Analysis and Classification System used by trained accident investigators. In this study, three trained instructor pilots used the DoD-HFACS to classify 347 U.S. Air Force Accident Investigation Board (AIB) Class-A reports between the years of 2000 and 2013. The overall method consisted of four steps: (1) train on HFACS definitions, (2) verify rating reliability, (3) rate HFACS reports, and (4) random …

Economics-Based Risk Management Of Distributed Denial Of Service Attacks: A Distance Learning Case Study, Omer Keskin, Unal Tatar, Omer Poyraz, Ariel Pinto, Adrian Gheorghe

Engineering Management & Systems Engineering Faculty Publications

Managing risk of cyber systems is still on the top of the agendas of Chief Information Security Officers (CISO). Investment in cybersecurity is continuously rising. Efficiency and effectiveness of cybersecurity investments are under scrutiny by boards of the companies. The primary method of decision making on cybersecurity adopts a risk-informed approach. Qualitative methods bring a notion of risk. However, particularly for strategic level decisions, more quantitative methods that can calculate the risk and impact in monetary values are required. In this study, a model is built to calculate the economic value of business interruption during a Distributed Denial-of-Service (DDoS) attack …

Cyber Security And Criminal Justice Programs In The United States: Exploring The Intersections, Brian K. Payne, Lora Hadzhidimova

Sociology & Criminal Justice Faculty Publications

The study of cyber security is an interdisciplinary pursuit that includes STEM disciplines as well as the social sciences. While research on cyber security appears to be central in STEM disciplines, it is not yet clear how central cyber security and cyber crime is to criminal justice scholarship. In order to examine the connections between cyber security and criminal justice, in this study attention is given to the way that criminal justice scholars have embraced cyber crime research and coursework. Results show that while there are a number of cyber crime courses included in criminal justice majors there are not …

A Multi-Criteria And Dynamic Sustainability Assessment Of Crop Rotation Alternatives, Saturnina Fabian Nisperos

Computational Modeling & Simulation Engineering Theses & Dissertations

With the food security challenge faced by nations globally, agriculture sustainability has been a significant consideration for concerned agencies. Sustainability assessments are significant tools in providing support to stakeholders in their crop production planning. Agricultural sustainability assessment, however, is complex and it involves numerous criteria that can be conflicting. Limitations on crop rotation sustainability assessment methods include: non-dynamic assessment; lack of regard to cover crops and to the individual crop production preferences of farmers; and focused only on single-year and single-crop rotation. We sought to address these limitations by developing a multi-criteria and dynamic sustainability assessment model that considers the …

Development And Evaluation Of Post-Production Oxygenation Techniques For The Augmentation Of Biochar, Matthew David Huff

Chemistry & Biochemistry Theses & Dissertations

Biochar is the carbon rich solid by-product of biomass pyrolysis. Interest in biochar can be broken down to several main categories: use as a carbon sequestration agent, use as a medium for the removal via adsorption of unwanted materials in wastewater, and as a soil amendment for the increase of cation exchange capacity (CEC). In order to generate a biochar which is stable enough for carbon sequestration, higher temperature pyrolysis must be used in order to ensure a lower O:C ratio in order to increase the half-life of biochar in soil. This dissertation addresses the evaluation of biochars made from …

Offshore Wind Energy: Simulating Local Offshore Wind Turbine, Ian P. Aquino

Mechanical & Aerospace Engineering Theses & Dissertations

Dominion Virginia Energy is looking at the possible creation of an offshore wind plant as a renewable source of electricity to be located off the coast of Virginia Beach. This thesis reports on a computer simulation based on local wind conditions and possible single wind turbine installation.

The National Buoy Data Center keeps records of the local wind conditions gathered in real time and available to the public. These data give a general overview of the wind conditions in Virginia Beach which is used to simulate atmospheric boundary layer (ABL) flow conditions and is subsequently used as input data for …

Approximation Of Quantiles Of Rank Test Statistics Using Almost Sure Limit Theorems, Mark Ledbetter

Mathematics & Statistics Theses & Dissertations

There are many problems in statistics where the analysis is based on asymptotic distributions. In some cases, the asymptotic distribution is in an open form or is intractable. One possible solution is the logarithmic quantile estimation (LQE) method introduced by Thangavelu (2005) for rank tests and Fridline (2010) for the correlation coefficient. LQE is derived from an almost sure version of the central limit theorem using the results of Berkes and Csaki (2001), and it estimates the quantiles of a test statistic using only the data. To date, LQE has been used in only a few applications. We extend the …

Human-Intelligence And Machine-Intelligence Decision Governance Formal Ontology, Faisal Mahmud

Engineering Management & Systems Engineering Theses & Dissertations

Since the beginning of the human race, decision making and rational thinking played a pivotal role for mankind to either exist and succeed or fail and become extinct. Self-awareness, cognitive thinking, creativity, and emotional magnitude allowed us to advance civilization and to take further steps toward achieving previously unreachable goals. From the invention of wheels to rockets and telegraph to satellite, all technological ventures went through many upgrades and updates. Recently, increasing computer CPU power and memory capacity contributed to smarter and faster computing appliances that, in turn, have accelerated the integration into and use of artificial intelligence (AI) in …

Deep Recurrent Learning For Efficient Image Recognition Using Small Data, Mahbubul Alam

Electrical & Computer Engineering Theses & Dissertations

Recognition is fundamental yet open and challenging problem in computer vision. Recognition involves the detection and interpretation of complex shapes of objects or persons from previous encounters or knowledge. Biological systems are considered as the most powerful, robust and generalized recognition models. The recent success of learning based mathematical models known as artificial neural networks, especially deep neural networks, have propelled researchers to utilize such architectures for developing bio-inspired computational recognition models. However, the computational complexity of these models increases proportionally to the challenges posed by the recognition problem, and more importantly, these models require a large amount of data …

Regional Sea Level Rise Along The United States Coasts, Alessandra G. Burgos

OES Theses and Dissertations

Over the past several years, there has been several studies focused on reconstructing global mean sea level (GMSL) for the 20th century, along with projecting rates out into the future. Of greater importance for mitigation and adaptation plans, however, is the rate of local or regional sea level (RSL) rise. Ocean dynamics along with changes in Earth’s gravitational field can cause RSL to deviate from the change in GMSL. During the satellite altimeter era covering the past two decades, RSL trends can be four times the global average, with much of this spatial variation due to internal climate variability. Isolating …

Structure Of The Picornavirus Replication Platform: A Potential Drug Target For Inhibiting Virus Replication, Meghan Suzanne Warden

Chemistry & Biochemistry Theses & Dissertations

Picornaviruses are small, positive-stranded RNA viruses, divided into twelve different genera. Members of the Picornaviridae family cause a wide range of human and animal diseases including the common cold, poliomyelitis, foot and mouth disease, and dilated cardiomyopathy. The picornavirus genome is replicated via a highly conserved mechanism involving a presumed cloverleaf structure located at the 5’ noncoding region of the virus genome. The 5’ cloverleaf consists of three stem loops (B, C, and D) and one stem (A), which interact with a variety of virus and host cell proteins during replication. In this dissertation, human rhinovirus serotype 14 (HRV-14) SLB …

Adaptive Methods For Point Cloud And Mesh Processing, Zinat Afrose

Computational Modeling & Simulation Engineering Theses & Dissertations

Point clouds and 3D meshes are widely used in numerous applications ranging from games to virtual reality to autonomous vehicles. This dissertation proposes several approaches for noise removal and calibration of noisy point cloud data and 3D mesh sharpening methods. Order statistic filters have been proven to be very successful in image processing and other domains as well. Different variations of order statistics filters originally proposed for image processing are extended to point cloud filtering in this dissertation. A brand-new adaptive vector median is proposed in this dissertation for removing noise and outliers from noisy point cloud data.

The major …

Crab Cavity Requirements For The Jefferson Lab Electron-Ion Collider, Salvador Isaac Sosa Güitrón

Physics Theses & Dissertations

An Electron-Ion Collider (EIC) has been proposed to be the next large facility to explore the dynamics of quarks and gluons inside nuclei. A conceptual design for a Jefferson Lab Electron-Ion Collider (JLEIC) is being developed. It is based on the CEBAF 12 GeV machine as a full energy electron beam injector. Two crucial requirements of JLEIC are high luminosity in the 10³⁴ cm^-2s^-1 range, and full acceptance detection of particles. The full acceptance requirement relies on having the beams collide at a relatively large crossing angle of 50 mrad. Such a large crossing angle, however, …

Development Of A 300 Kv Dc High Voltage Photogun And Beam Based Studies Of Alkali Antimonide Photocathodes, Yan Wang

Physics Theses & Dissertations

To advance magnetized gun research in the United States, a compact DC high voltage photogun with inverted-insulator geometry was designed, built, and operated reliably at - 300 kV bias voltage using alkali-antimonide photocathodes. This photogun will provide a magnetized electron beam for the future Jefferson Lab Electron-Ion Collider (JLEIC) cooler. This research describes key electrostatic design features of the photogun and evaluates the performance of the in-house fabricated photocathodes and the quality of the electron beams. The thermal emittance of the electron beam was measured with various conditions: different gun bias voltages, different laser spot sizes, and photocathodes with different …

Applying Machine Learning To Advance Cyber Security: Network Based Intrusion Detection Systems, Hassan Hadi Latheeth Al-Maksousy

Computer Science Theses & Dissertations

Many new devices, such as phones and tablets as well as traditional computer systems, rely on wireless connections to the Internet and are susceptible to attacks. Two important types of attacks are the use of malware and exploiting Internet protocol vulnerabilities in devices and network systems. These attacks form a threat on many levels and therefore any approach to dealing with these nefarious attacks will take several methods to counter. In this research, we utilize machine learning to detect and classify malware, visualize, detect and classify worms, as well as detect deauthentication attacks, a form of Denial of Service (DoS). …

Synthesis And Characterization Of Glycolipids, Glycoclusters And Glycomacrocycles, Anji Chen

Chemistry & Biochemistry Theses & Dissertations

Low molecular-weight gelators (LMWGs) are a fascinating and interesting class of compounds that can self-assemble and form supramolecular structures in appropriate solvents. The gelators form fibrous networks which entrap the solvent and result in a supramolecular gel. Carbohydrate-derived LMWGs are especially useful since they are more likely to be biocompatible and biodegradable. Dendritic gelators are branch-shaped molecules with precise molecular weight that are between small molecules and polymer gelators. Glycoclusters with sugar moieties at the periphery of the molecules are important classes of bioactive compounds due to the multivalency effect. Lower generation glycoclusters are relatively small branched systems that have …

Wet And Dry Atmospheric Deposition Of Nutrients And Bioactive Trace Metals To Coastal Waters Of The Mid-Atlantic Bight, Christine Sookhdeo

OES Theses and Dissertations

Atmospheric deposition provides a significant source of nutrients and bioactive trace metals to the surface ocean, including the seasonally oligotrophic waters of the Mid-Atlantic Bight. These atmospherically derived nutrients and trace metals enter the surface ocean via dry deposition of aerosols and wet deposition in rain. To estimate the aeolian input of nutrients and trace metals to coastal waters east of the Delmarva Peninsula, wet and dry atmospheric deposition samples were collected over a one-year time series at the Anheuser-Busch Coastal Research Center, Oyster, Virginia. Weekly composite samples were collected from May 2014 through June 2015. Nutrient species examined were …

Computational Investigation Of Energetic Materials: Influence Of Intramolecular And Intermolecular Interactions On Sensitivity, Ashley Lauren Shoaf

Chemistry & Biochemistry Theses & Dissertations

The development of novel high energy density materials (HEDMs) with superior energetic properties depends on characterizing how and why detonation occurs. Detonation is highly energetic and a nearly instantaneous process, making experimental studies challenging; thus, computational modeling through density functional theory (DFT) and molecular dynamics (MD) can be used to propose weakened, or activated, bonds that break to initiate explosive decomposition, termed trigger bonds. Bond activation is characterized by the Wiberg bond index (WBI), a measure of interatomic electron density. Trigger bonds in HEDMs are commonly found in explosophores, functional groups that contribute to energetic potential such as X-NO_{2 …}

Development Of A Laser-Spark Multicharged Ion System – Application In Shallow Implantation Of Sic By Boron And Barium, Md. Haider Ali Shaim

Electrical & Computer Engineering Theses & Dissertations

A novel multicharged ion source, using laser ablation induced plasma coupled with spark discharge, has been investigated in this work. The designed and demonstrated ion source is cost-effective, compact and versatile. Experiments are described with the intention of demonstrating the practicability of ion implantation via laser ion source.

Multicharged aluminum ions are generated by a ns Q-switched Nd:YAG laser pulse ablation of an aluminum target in an ultrahigh vacuum. The experiments are conducted using laser pulse energies of 45–90 mJ focused on the Al target surface by a lens with an 80-cm focal length to 0.0024 cm² spot area …