Physical Sciences and Mathematics Commons^™

A Comparison Of Classical Versus Deep Learning Techniques For Abusive Content Detection On Social Media Sites, Hao Che, Susan Mckeever, Sarah Jane Delany

Conference papers

The automated detection of abusive content on social media websites faces a variety of challenges including imbalanced training sets, the identification of an appropriate feature representation and the selection of optimal classifiers. Classifiers such as support vector machines (SVM), combined with bag of words or ngram feature representation, have traditionally dominated in text classification for decades. With the recent emergence of deep learning and word embeddings, an increasing number of researchers have started to focus on deep neural networks. In this paper, our aim is to explore cutting-edge techniques in automated abusive content detection. We use two deep learning approaches: …

First Search For Nontensorial Gravitational Waves From Known Pulsars, Benjamin P. Abbott, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper …

Determining Tidal Characteristics In A Restored Tidal Wetland Using Unmanned Aerial Vehicles And Derived Data, Victor Thornton

Theses and Dissertations

Unmanned aerial vehicle (UAV) technology was used to determine tidal extent in Kimages Creek, a restored tidal wetland located in Charles City County, Virginia. A Sensefly eBee Real-Time Kinematic UAV equipped with the Sensor Optimized for Drone Applications (SODA) camera (20-megapixel RGB sensor) was flown during a single high and low tide event in Summer 2017. Collectively, over 1,300 images were captured and processed using Pix4D. Horizontal and vertical accuracy of models created using ground control points (GCP) ranged from 0.176 m to 0.363 m. The high tide elevation model was subtracted from the low tide using the ArcMap 10.5.1 …

Decoupled, Linear, And Energy Stable Finite Element Method For The Cahn-Hilliard-Navier-Stokes-Darcy Phase Field Model, Yali Gao, Xiaoming He, Liquan Mei, Xiaofeng Yang

Mathematics and Statistics Faculty Research & Creative Works

In this paper, we consider the numerical approximation for a phase field model of the coupled two-phase free flow and two-phase porous media flow. This model consists of Cahn—Hilliard—Navier—Stokes equations in the free flow region and Cahn—Hilliard—Darcy equations in the porous media region that are coupled by seven interface conditions. The coupled system is decoupled based on the interface conditions and the solution values on the interface from the previous time step. A fully discretized scheme with finite elements for the spatial discretization is developed to solve the decoupled system. In order to deal with the difficulties arising from the …

Green Function Of The Poisson Equation: D = 2, 3, 4, Ulrich D. Jentschura, J. Sapirstein

Physics Faculty Research & Creative Works

We study the Green function of the Poisson equation in two, three and four dimensions. The solution g of the equation ∇→2 g(x→ - x→') = δ(D) (x→ - x→') where x→ and x→' are D-dimensional position vectors, is customarily expanded into radial and angular coordinates. For the two-dimensional case (D = 2), we find a subtle interplay of the necessarily introduced scale L with the radial component of zero magnetic quantum number. For D = 3, the well-known expressions are briefly recalled; this is done in order to highlight the analogy with the four-dimensional case, where we uncover analogies …

Many-Body Dissipative Flow Of A Confined Scalar Bose-Einstein Condensate Driven By A Gaussian Impurity, Garyfallia C. Katsimiga, Simeon I. Mistakidis, G. M. Koutentakis, P. G. Kevrekidis, P. Schmelcher

Physics Faculty Research & Creative Works

The Many-Body Dissipative Flow Induced By A Mobile Gaussian Impurity Harmonically Oscillating Within A Cigar-Shaped Bose-Einstein Condensate Is Investigated. For Very Small And Large Driving Frequencies The Superfluid Phase Is Preserved. Dissipation Is Identified, For Intermediate Driving Frequencies, By The Nonzero Value Of The Drag Force Whose Abrupt Increase Signals The Spontaneous Downstream Emission Of An Array Of Gray Solitons. After Each Emission Event, Typically Each Of The Solitary Waves Formed Decays And Splits Into Two Daughter Gray Solitary Waves That Are Found To Be Robust Propagating In The Bosonic Background For Large Evolution Times. In Particular, A Smooth Transition …

Disposable Printed Lateral Flow Electrochemical Immunosensors For Human Cardiac Troponin T, Eithne Dempsey, Dhanraj Rathod

Articles

Here we report an electrochemical ELISA approach for cardiac Troponin T (cTnT) determination based on a lateral flow membrane with underlying screen printed electrodes (<;100 Ω /cm 2 ). The thick film transducer was modified with the anti-cardiac Troponin T antibody via physisorption and the electrochemical performance of the immunosensor was evaluated using cyclic voltammetry. The capture antibody coated immunoelectrode employed for electrochemical determination of Troponin T antigen used a sandwich assay format with horseradish peroxidase conjugated signaling antibodies held in the track of a lateral flow sensor strip. A simple two step procedure realized signal acquisition within <;20 min (total assay time). The lateral flow electrochemical immunosensor response resulted in a calibration curve with linear response (0-700 ng/ml cTnT) with limit of detection of 0.15 ng/ml.

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 …}

In Praise Of The Catenary, Fred Behroozi

Faculty Work

When a chain hangs loosely from its end points, it takes the familiar form known as the catenary. Power lines, clothes lines, and chain links are familiar examples of the catenary in everyday life. Nevertheless, the subject is conspicuously absent from current introductory physics and calculus courses.1 Even in upper-level physics and math courses, the catenary equation is usually introduced as an example of hyperbolic functions or discussed as an application of the calculus of variations. We present a new derivation of the catenary equation that is suitable for introductory physics and mathematics courses.

Utilizing Hypervisor To Enhance Trustzone’S Introspection Capabilities On Non-Secure World, Zhang-Kai Zhang, Zhou-Jun Li, Chun-He Xia, Jin-Xin Ma, Jinhua Cui

Research Collection School Of Computing and Information Systems

Widely used on the Android phones, the technology of ARM TrustZone divides the hardware resources of Android phones into two worlds:non-secure world and secure world. The Android operating system used by user is running in the non-secure world, while the non-secure world's introspection systems (e.g., KNOX, Hypervisor) that are based on TrustZone are running in the secure world. These introspection systems have the high privilege. They can dynamically check Android kernel integrity and perform memory management of non-secure world instead of Android kernel. But TrustZonecan can not completely introspect the hardware resources (e.g., Cache) of non-secure world because of the …

Multi-Target Deep Neural Networks: Theoretical Analysis And Implementation, Zeng Zeng, Nanying Liang, Xulei Yang, Steven C. H. Hoi

Research Collection School Of Computing and Information Systems

In this work, we propose a novel deep neural network referred to as Multi-Target Deep Neural Network (MT-DNN). We theoretically prove that different stable target models with shared learning paths are stable and can achieve optimal solutions respectively. Based on GoogleNet, we design a single model with three different targets, one for classification, one for regression, and one for masks that is composed of 256  ×  256 sub-models. Unlike bounding boxes used in ImageNet, our single model can draw the shapes of target objects, and in the meanwhile, classify the objects and calculate their sizes. We validate our single MT-DNN …

205.3 The Many Shapes Of Archive-It, Shawn Jones, Michael L. Nelson, Alexander Nwala, Michele C. Weigle

Computer Science Faculty Publications

Web archives, a key area of digital preservation, meet the needs of journalists, social scientists, historians, and government organizations. The use cases for these groups often require that they guide the archiving process themselves, selecting their own original resources, or seeds, and creating their own web archive collections. We focus on the collections within Archive-It, a subscription service started by the Internet Archive in 2005 for the purpose of allowing organizations to create their own collections of archived web pages, or mementos. Understanding these collections could be done via their user-supplied metadata or via text analysis, but the metadata is …

Client-Assisted Memento Aggregation Using The Prefer Header, Mat Kelly, Sawood Alam, Michael L. Nelson, Michele C. Weigle

Computer Science Faculty Publications

[First paragraph] Preservation of the Web ensures that future generations have a picture of how the web was. Web archives like Internet Archive's Wayback Machine, WebCite, and archive.is allow individuals to submit URIs to be archived, but the captures they preserve then reside at the archives. Traversing these captures in time as preserved by multiple archive sources (using Memento [8]) provides a more comprehensive picture of the past Web than relying on a single archive. Some content on the Web, such as content behind authentication, may be unsuitable or inaccessible for preservation by these organizations. Furthermore, this content may be …

Anatomy Of An Interrupted Irrigation Season: Micro-Drought At The Wind River Indian Reservation, Shannon M. Mcneeley, Cadida F. Dewes, Crystal J. Stiles, Tyler A. Beeton, Imtiaz Rangwala, Michael T. Hobbins, Cody L. Knutson

School of Natural Resources: Faculty Publications

Drought is a complex phenomenon manifested through interactions between biophysical and social factors. At the Wind River Indian Reservation (WRIR) in west-central Wyoming, water shortages have become increasingly common since the turn of the 21st century. Here we discuss the 2015 water year as an exemplar year, which was characterized by wetter-than-normal conditions across the reservation and, according to the U.S. Drought Monitor, remained drought-free throughout the year. Yet parts of the reservation experienced harmful water shortages, or “microdrought” conditions, during the growing season in 2015. In this assessment of the 2015 water year at the WRIR we: (1) describe …

Global Plate Motions And Earthquake Cycle Effects, Shannon E. Graham, John P. Loveless, Brendan J. Meade

Geosciences: Faculty Publications

The rotations of tectonic plates provide a partial description of the total observed displacements at the Earth’s surface. The estimated number of kinematically distinct plates has increased from 12 in 1990 to 56 in 2010 as a result of the increase in the number of kinematic observables. At length scales <1,000 km, rotation-only plate models are inaccurate because geodetic signals of long-term plate motions are complicated by earthquake cycle effects. Here we present results from a global block model that unifies large-scale plate motions and local earthquake cycle effects at plate boundaries. Incorporating the rotations of 307 distinct plates, elastic strain accumulation from 16 subduction zones and 1.59×107 km2 of fault system area, this model explains 19,664 interseismic GPS velocities at a resolution of 2.2 mm/year. Geodetically constrained fault slip deficit rates yield a cumulative global moment accumulation rate of 1.09 × 1022 N⋅m/year, 12% larger than the average annual coseismic moment release rate from 1900 to 2013. The potential contribution to the total moment rate budget can be estimated from the frequency distribution of the modeled fault slip-deficit rates, which follow an exponential distribution. Integrating this frequency distribution over all possible slip rates indicates that the geologic structures included in this reference global block model account for 98% of the global moment budget. Comparing our results with population distribution, we find that ∼50% of the world’s population lives within 200 km of an active fault with a slip rate >2 mm/year.

Life In Hampton Roads Survey Press Release #6: Sea Level Rise And Flooding, Social Science Research Center, Old Dominion University

Life in Hampton Roads Survey Report

[Introductory paragraph]

This report examines regional measures of environmental risk perceptions from the 2018 Life In Hampton Roads survey (LIHR 2018) conducted by the Old Dominion University Social Science Research Center. Data from prior years is also provided when available to show comparisons in responses over time. Responses were weighted by city population, race, age, gender, and phone usage (cell versus land-line) to be representative of the Hampton Roads region. For additional information on survey methodology, and analyses of other issues, please see the SSRC website at www.odu.edu/ssrc. The 2018 Life in Hampton Roads survey included a series of …

Enzymatic Activity Of Endophytic Bacterial Isolates From Selected Mangrove Plants In Kenya, Regina M. Ntabo, Anthony Kebira Nyamache, Wilber Lwande, James Kabii, James Nonoh

All Peer-Reviewed Publications

Introduction: Microorganisms are a preferred source of enzyme production due to their high production capability and low cost of production. Bacterial endophytes occupy unexplored sites hence they represent a new source of enzymes with diverse applications. Mangrove plants in Kenya have traditionally been used as medicinal plants due to their bioactive metabolites. However the enzymatic activity of mangrove plants associated endophytes has not been studied. Aims & Objectives: The study is aimed at bioprospecting for enzymes with potential biotechnological applications from mangrove ecosystems. Methods & Materials: Forty-two bacterial isolates were cultured and isolated from the leaves and roots of six …

Application Of Evolutionary Network Concept In Structuring Mathematics Curriculum, Aditi Mitra

College of Graduate Studies: Theses & Dissertations

Phylogenetic tree and in general, evolutionary network, has found its application well beyond the biological fields and has even percolated into recent high demanding areas, such as data mining and social media chain reactions. An extensive survey of its current applications are presented here. An attempt has been made to apply the very concept in the mathematics course curriculum inside a degree program. Various features of the tree structure are identified within the curriculum network. To highlight various key components and to enhance the visual effect, several diagrams are presented. The combined effect of these diagram provides a sense of …

Exploring New Synthetic Strategies By Using Novel Manganese Carboxylate Complexes Along With Two Alkoxide Based Ligands, 2-(Hydroxymethyl)-Pyridine And 4,5-Bis(Hydroxymethyl)-2-Methylpyridin-3-Ol In The Area Of Polynuclear Coordination Chemistry, Michael A. Reagan

College of Graduate Studies: Theses & Dissertations

Manganese carboxylate complexes have been well studied in the past, due to their relevance in bioinorganic chemistry and as well as their behavior as nanoscale magnetic materials that is called single-molecule magnets (SMMs). SMMs are special class of magnetic materials in which magnetism is intrinsic to the molecule. Polynuclear manganese clusters often possess high spin ground states as well as large and negative magnetoanisotropy, a combination which leads to an energy barrier for the reversal of the magnetization direction. The paramagnetic nature of manganese at its common oxidation states with an ample number of unpaired electrons often leads to high-nuclearity …

A Comparison Of Bridge Deterioration Models, Toktam Naderimoghaddam

College of Graduate Studies: Theses & Dissertations

Predicting how bridges will deteriorate is the key to budgeting financial and personnel resources. Deterioration models exist for specific components of a bridge, but no models exist for the sufficiency rating which is an overall measure of the condition and relevance of a bridge used for determining eligibility for federal funds.

We have 25 years worth of data collected by the Georgia Department of Transportation from 1992 to 2016 about all bridges in the State of Georgia. More precisely, each row in this data set includes the characteristics of each bridge along with the sufficiency rating of that bridge in …

Cellulose Modification For Use As Reinforcement In Bio-Based Composites, Ashley L. Rudolph

College of Graduate Studies: Theses & Dissertations

The goal of the research contained in this thesis is to provide an alternative method of developing polymers than the current petroleum-based polymeric products. Vegetable oil-based polymers are a popular alternative due to their low-cost and low toxicity. The carbon-carbon double bonds in the oil are ideal reactive sites for a free radical polymerization. Cellulose is a naturally occurring polymer. Modifying cellulose prior to making composites with tung oil allows a hydrophilic material to mix better with a hydrophobic resin. Vegetable oil-based polymers usually require the reinforcement of fibers to enhance the thermo-mechanical properties that would replace petroleum-based polymers. In …

Sparse Trees With A Given Degree Sequence, Ao Shen

College of Graduate Studies: Theses & Dissertations

In this thesis, we consider the properties of sparse trees and summarized a certain class of trees under some constraint (including with a given degree sequence, with given number of leaves, with given maximum degree, etc.) which have maximum Wiener index and the minimum number of subtrees at the same time. Wiener index is one of the most important topological indices in chemical graph theory. Steiner k�� Wiener index can be regarded as the generalization of Wiener index, when k = 2, Steiner Wiener index is the same as Wiener index. Steiner k�� Wiener index of a tree T is …

Isolated Mobile Malware Observation, Augustine Paul

College of Graduate Studies: Theses & Dissertations

The idea behind Bring Your Own Device (BYOD) it that personal mobile devices can be used in the workplace to enhance convenience and flexibility. This development encourages organizations to allow access of personal mobile devices to business information and systems for businesses operation. However, BYOD opens a firm to various security risks such as data contamination and the exposure of user interest to criminal activities. Mobile devices were not designed to handle intense data security and advanced security features are frequently turned off. Using personal mobile devices can also expose a system to various forms of security threats like malware. …

A Journey To The Adic World, Fayadh Kadhem

College of Graduate Studies: Theses & Dissertations

The first idea of this research was to study a topic that is related to both Algebra and Topology and explore a tool that connects them together. That was the entrance for me to the “adic world”. What was needed were some important concepts from Algebra and Topology, and so they are treated in the first two chapters.

The reader is assumed to be familiar with Abstract Algebra and Topology, especially with Ring theory and basics of Point-set Topology.

The thesis consists of a motivation and four chapters, the third and the fourth being the main ones. In the third …

Multiclass Classification Using Support Vector Machines, Duleep Prasanna W. Rathgamage Don

College of Graduate Studies: Theses & Dissertations

In this thesis, we discuss different SVM methods for multiclass classification and introduce the Divide and Conquer Support Vector Machine (DCSVM) algorithm which relies on data sparsity in high dimensional space and performs a smart partitioning of the whole training data set into disjoint subsets that are easily separable. A single prediction performed between two partitions eliminates one or more classes in a single partition, leaving only a reduced number of candidate classes for subsequent steps. The algorithm continues recursively, reducing the number of classes at each step until a final binary decision is made between the last two classes …

Ingredients For Understanding Brain And Behavioral Evolution: Ecology, Phylogeny, And Mechanism, Stephen H. Montgomer, Adrian Currie, Dieter Lukas, Neeltje Boogert, Andrew Buskell, Fiona R. Cross, Sarah Jelbert, Shahar Avin, Rafael Mares, Ana F. Navarrete, Shuichi Shigeno, Corina J. Logan

All Peer-Reviewed Publications

Uncovering the neural correlates and evolutionary drivers of behavioral and cognitive traits has been held back by traditional perspectives on which correlations to look for-in particular, anthropocentric conceptions of cognition and coarse-grained brain measurements. We welcome our colleagues' comments on our overview of the field and their suggestions for how to move forward. Here, we counter, clarify, and extend some points, focusing on the merits of looking for the "best" predictor of cognitive ability, the sources and meaning of "noise," and the ways in which we can deduce and test meaningful conclusions from comparative analyses of complex traits.

Minimally Actuated Walking: Identifying Core Challenges To Economical Legged Locomotion Reveals Novel Solutions, Ryan T. Schroeder, John Ea Bertram

Research outputs 2014 to 2021

Terrestrial organisms adept at locomotion employ strut-like legs for economical and robust movement across the substrate. Although it is relatively easy to observe and analyze details of the solutions these organic systems have arrived at, it is not as easy to identify the problems these movement strategies have solved. As such, it is useful to investigate fundamental challenges that effective legged locomotion overcomes in order to understand why the mechanisms employed by biological systems provide viable solutions to these challenges. Such insight can inform the design and development of legged robots that may eventually match or exceed animal performance. In …

A Marine Heatwave Drives Massive Losses From The World’S Largest Seagrass Carbon Stocks, A. Arias-Ortiz, Oscar Serrano, Pere Masque´, Paul S. Lavery, Ute Mueller, G. A. Kendrick, Mohammad Rozaimi, Alba Esteban, J. W. Fourqurean, N. Marba, Miguel-Angel Mateo, K. Murray, M. J. Rule, C. M. Duarte

Research outputs 2014 to 2021

Seagrass ecosystems contain globally significant organic carbon (C) stocks. However, climate change and increasing frequency of extreme events threaten their preservation. Shark Bay, Western Australia, has the largest C stock reported for a seagrass ecosystem, containing up to 1.3% of the total C stored within the top metre of seagrass sediments worldwide. On the basis of field studies and satellite imagery, we estimate that 36% of Shark Bay’s seagrass meadows were damaged following a marine heatwave in 2010/2011. Assuming that 10 to 50% of the seagrass sediment C stock was exposed to oxic conditions after disturbance, between 2 and 9 …

Coagulation And Electrocoagulation For Co-Treatment Of Stabilized Landfill Leachate And Municipal Wastewater, Mohini Verma, R. Naresh Kumar

Research outputs 2014 to 2021

Landfill leachate and municipal wastewater at various ratios (1:20, 1:10, 1:7 and 1:5) were subjected to coagulation and electrocoagulation (EC). Alum was used in conventional coagulation at pH 6 and aluminum plate as electrode was used in EC at a current density of 386 A/m² with 5 cm inter electrode spacing. Treatment efficiency was assessed from removal of chemical oxygen demand (COD), total suspended solids (TSS), turbidity, ammonia, nitrate and phosphate. At 1:5 ratio of landfill leachate to municipal wastewater, highest COD removal was with 3.8 g/L alum whereas highest turbidity removal was with 3.3 g/L alum during coagulation. …

Reimagining The Cultural Significance Of Wetlands: From Perth’S Lost Swamps To The Beeliar Wetlands, Danielle Brady, Jeffrey Murray

Research outputs 2014 to 2021

The history of Perth, Western Australia, has been characterised by the incremental loss of its wetlands. While disputes about wetlands are often framed solely in terms of the environment, they are places of cultural significance too. The extensive wetlands of central Perth, food gathering and meeting places for Noongar people are now expunged from the landscape. Urban dwellers of Perth are largely unaware that the seasonal lakes and wetlands of the centre of the city were the larders, gardens, hideouts, dumps and playgrounds of previous generations; both Noongar and Settler. The loss of social memory of these lost cultural/natural places …