Physical Sciences and Mathematics Commons^™

Cosm News, Georgia Southern University

College of Science & Mathematics: News & Publications (2012-2022)

• Alumnus receives 2016 National Space Club Lifetime Achievement Award

Landmark Detection With Surprise Saliency Using Convolutional Neural Networks, Feng Tang, Damian Lyons, Daniel Leeds

Faculty Publications

Abstract—Landmarks can be used as reference to enable people or robots to localize themselves or to navigate in their environment. Automatic definition and extraction of appropriate landmarks from the environment has proven to be a challenging task when pre-defined landmarks are not present. We propose a novel computational model of automatic landmark detection from a single image without any pre-defined landmark database. The hypothesis is that if an object looks abnormal due to its atypical scene context (what we call surprise saliency), it then may be considered as a good landmark because it is unique and easy to spot by …

Hyperplanes That Intersect Each Ray Of A Cone Once And A Banach Space Counterexample, Chris Mccarthy

Publications and Research

Suppose � is a cone contained in real vector space �. When does � contain a hyperplane � that intersects each of the 0-rays in �\{0} exactly once? We build on results found in Aliprantis, Tourky, and Klee Jr.’s work to give a partial answer to this question.We also present an example of a salient, closed Banach space cone � for which there does not exist a hyperplane that intersects each 0-ray in � \ {0} exactly once.

Representing Uncertainty On Model Analysis Plots, Trevor I. Smith

College of Science & Mathematics Departmental Research

Model analysis provides a mechanism for representing student learning as measured by standard multiple-choice surveys. The model plot contains information regarding both how likely students in a particular class are to choose the correct answer and how likely they are to choose an answer consistent with a well-documented conceptual model. Unfortunately, Bao’s original presentation of the model plot did not include a way to represent uncertainty in these measurements. I present details of a method to add error bars to model plots by expanding the work of Sommer and Lindell. I also provide a template for generating model plots with …

Future Changes In Propagating And Non-Propagating Diurnal Rainfall Over East Asia, Wan-Ru Huang, Shih-Yu (Simon) Wang

Plants, Soils, and Climate Faculty Publications

The characteristics of diurnal rainfall in the East Asian continent consist of a propagating regime over the Yangtze River and a non-propagating regime in southeast China. Simulations of these two diurnal rainfall regimes by 18 CMIP5 models were evaluated from the historical experiment of 1981–2005. The evaluation led to the identification of one model, the CMCC-CM that replicated the key characteristics of diurnal rainfall regimes including the propagation of moisture convergence. Using the CMCC-CM to assess the future (2076–2100) change of diurnal evolution and propagation projected by the RCP4.5 experiment, it was found that propagating diurnal rainfall will enhance and …

A New Class Of Allosteric Hiv-1 Integrase Inhibitors Identified By Crstallographic Fragment Screening Of The Catalytic Core Domain, Disha Patel, Janet Antwi, Pratibha C. Koneru, Erik Serrao, Stefano Forli, Jacques J. Kessl, Lei Feng, Nanjie Deng, Ronald M. Levy, James R. Fuchs, Arthur J. Olson, Alan N. Engelman, Joseph D. Bauman, Mamuka Kvaratskhelia, Eddy Arnold

Faculty Publications

HIV-1 integrase (IN) is essential for virus replication and represents an important multifunctional therapeutic target. Recently discovered quinoline-based allosteric IN inhibitors (ALLINIs) potently impair HIV-1 replication and are currently in clinical trials. ALLINIs exhibit a multimodal mechanism of action by inducing aberrant IN multimerization during virion morphogenesis and by competing with IN for binding to its cognate cellular cofactor LEDGF/p75 during early steps of HIV-1 infection. However, quinoline-based ALLINIs impose a low genetic barrier for the evolution of resistant phenotypes, which highlights a need for discovery of second-generation inhibitors. Using crystallographic screening of a library of 971 fragments against the …

Competition Between Hydrophilic And Argyrophilic Interactions In Surface Enhanced Raman Spectroscopy, John T. Kelly, Annie K. Mcclellan, Lynn V. Joe, Ashley M. Wright, Lawson T. Lloyd, Gregory S. Tschumper, Nathan I. Hammer

Chemistry Faculty Research & Creative Works

The competition for binding and charge-transfer (CT) from the nitrogen containing heterocycle pyrimidine to either silver or to water in surface enhanced Raman spectroscopy (SERS) is discussed. The correlation between the shifting observed for vibrational normal modes and CT is analyzed both experimentally using Raman spectroscopy and theoretically using electronic structure theory. Discrete features in the Raman spectrum correspond to the binding of either water or silver to each of pyrimidine's nitrogen atoms with comparable frequency shifts. Natural bond orbital (NBO) calculations in each chemical environment reveal that the magnitude of charge transfer from pyrimidine to adjacent silver atoms is …

Interactions Between Temozolomide And Guanine And Its S And Se‐Substituted Analogues, Okuma Emile Kasende, Aristote Matondo, Jules Tshishimbi Muya, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Temozolomide was paired with guanine, 6-selenoguanine, and 6-thioguanine, as well as the SH tautomer of the latter. The potential energy surface of each heterodimer was searched for all minima, using Dispersion-Corrected Density Functional Theory and MP2 methods. Among the dozens of minima, three categories were observed. Stacked geometries place the aromatic systems of the two molecules parallel to one another, while the two systems are roughly perpendicular to one another in a second category. Also found are coplanar structures held together by H-bonds. Dispersion proves to be a dominating attractive force for the stacked structures, less so for perpendicular, and …

On A Multidimensional Spherically Invariant Extension Of The Rademacher-Gaussian Comparison, Iosif Pinelis

Department of Mathematical Sciences Publications

It is shown that P(ǁa₁U₁+ · · · +a_nU_nǁ > u) ≤ cP(aǁZ_dǁ> u) for all real u, where U₁, : : : , U_n are independent random vectors uniformly distributed on the unit sphere in R^d, a₁, : : : , a_n are any real numbers, a := √(a²₁ + · · · · + a²_n ) ∕ d, Z_d is a standard normal random vector in R^d, and c = 2e³ ∕ 9 …

Investigating The Impact Of Unsupervised Feature-Extraction From Multi-Wavelength Image Data For Photometric Classification Of Stars, Galaxies And Qsos, Annika Lindh

Dissertations

This thesis reviews the current state of photometric classification in Astronomy and identifies two main gaps: a dependence on handcrafted rules, and a lack of interpretability in the more successful classifiers. To address this, Deep Learning and Computer Vision were used to create a more interpretable model, using unsupervised training to reduce human bias.

The main contribution is the investigation into the impact of using unsupervised feature-extraction from multi-wavelength image data for the classification task. The feature-extraction is achieved by implementing an unsupervised Deep Belief Network to extract lower-dimensionality features from the multi-wavelength image data captured by the Sloan Digital …

Electrophilic Activation Of Silicon–Hydrogen Bonds In Catalytic Hydrosilations, Mark C. Lipke, Allegra L. Liberman-Martin, T. Don Tilley

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Hydrosilation reactions represent an important class of chemical transformations and there has been considerable recent interest in expanding the scope of these reactions by developing new catalysts. A major theme to emerge from these investigations is the development of catalysts with electrophilic character that transfer electrophilicity to silicon by Si-H activation. This type of mechanism has been proposed for catalysts ranging from Group 4 transition metals to Group 15 main group species. Additionally, other electrophilic silicon species, such as silylene complexes and η3-H2SiRR′ complexes, have been identified as intermediates in hydrosilation reactions. In this Review, different types of catalysts are …

Culture And Conservation: Beyond Anthropocentrism, Nathan Poirier

Journal of Ecological Anthropology

No abstract provided.

Observation Of Spatial Charge And Spin Correlations In The 2d Fermi-Hubbard Model, Lawrence Cheuk, Matthew Nichols, Katherine Lawrence, Melih Okan, Hao Zhang, Ehsan Khatami, Nandini Trivedi, Thereza Paiva, Marcos Rigol, Martin Zwierlein

Faculty Publications

Strong electron correlations lie at the origin of high-temperature superconductivity. Its essence is believed to be captured by the Fermi-Hubbard model of repulsively interacting fermions on a lattice. Here we report on the site-resolved observation of charge and spin correlations in the two-dimensional (2D) Fermi-Hubbard model realized with ultracold atoms. Antiferromagnetic spin correlations are maximal at half-filling and weaken monotonically upon doping. At large doping, nearest-neighbor correlations between singly charged sites are negative, revealing the formation of a correlation hole, the suppressed probability of finding two fermions near each other. As the doping is reduced, the correlations become positive, signaling …

Dynamics Of Orographic Gravity Waves Observed In The Mesosphere Over Auckland Islands During The Deep Propagating Gravity Wave Experiment (Deepwave), Stephen D. Eckermann, Dave Broutman, Jun Ma, James D. Doyle, Pierre-Dominique Pautet, Michael J. Taylor, Katrina Bossert, Bifford P. Williams, David C. Fritts, Ronald B. Smith

Publications

On 14 July 2014 during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), aircraft remote sensing instruments detected large-amplitude gravity wave oscillations within mesospheric airglow and sodium layers at altitudes z ~ 78–83 km downstream of the Auckland Islands, located ~1000 km south of Christchurch, New Zealand. A high-altitude reanalysis and a three-dimensional Fourier gravity wave model are used to investigate the dynamics of this event. At 0700 UTC when the first observations were made, surface flow across the islands’ terrain generated linear three-dimensional wave fields that propagated rapidly to z ~ 78 km, where intense breaking occurred in a narrow …

Blake Tullis Receives Prestigous Asdso Award, Utah Water Research Laboratory

News

Dr. Blake Tullis was recently selected to receive the 2016 ASDSO Terry L. Hampton Medal. This award was established in 2007 to recognize individuals who have made outstanding contributions to dam safety. Recipients must work the field of dam safety, hydrology, and hydraulics; conduct hydrologic or hydraulic research related to dams of significant impact to dam engineering; participate in organizations focused on dams, dam safety, dam engineering, etc.; and have made significant contributions to the practice of hydrologic and/or hydraulic engineering for dams.

Mathematical And Numerical Approaches To Cracked Euler-Bernoulli Beams, Jay Mayfield

Student Theses and Dissertations

We consider a nonlinear hyperbolic fourth order partial differential equation and ordinary differential equation mathematically and numerically that describe the motion of cracked Euler-Bernoulli beams. We assume that the endpoints of the beams are clamped and a crack in the beams is modeled by a set of natural boundary conditions. The effect of the crack on the beams increases in time, which is seen from the damage function. The beams will oscillate transversely in space until they break at the point of the crack. The midpoint rule is applied to a discretized time domain. Fully discrete numerical schemes are proposed …

Nutrient Reduction Design For Sustainable Municipal Wastewater Treatment, Lisa Brandon Ellington

Student Theses and Dissertations

Wastewater treatment plants (WWTPs) were designed for the removal of pollutants during management of reclaimed water to protect and prevent impairment of water resources. Pollutants not eliminated from WWTP discharges could possibly cause damage to receiving streams and sources of drinking water. Eutrophication has degraded water quality, with the primary factors established as nitrogen and phosphorus contamination in discharges to receiving streams from point and nonpoint sources. The United States Environmental Protection Agency (U.S. EPA), through regulations established under the Clean Water Act (CWA), has been compelled to determine nitrogen and phosphorus limits for inclusion in National Pollutant Discharge Elimination …

Implementing Some Basic Simuation Designs Using The Simsem Package In R, Keith A. Markus

Open Educational Resources

The purpose of this tutorial is to provide a very basic introduction to implementing three simple research designs using the simsem package in R. R is an open source statistical computing environment (R Core Team, 2015). For more information about R, see the R Project homepage (https://www.r-project.org/) and the Comprehensive R Archive Network (CRAN) web page (https://cran.r-project.org/). The lavaan package provides functions for fitting and evaluating structural equation models (Rosseel, 2012). For further information about the lavaan package including tutorials, see the lavaan Project web page (http://lavaan.ugent.be/). The simsem package (Pornprasertmanit, Miller & Schoemann, 2016) provides functions to facilitate structural …

Long Term Optimal Portfolio Selection Problem In Different Models, Bowen Hu

Mathematics Theses and Dissertations

In this project, we mainly focus on how to set up a complete methodology for finding the best investment portfolio which is meeting investor's risk preferences. In order to consider different aspects of their risk preferences, we use a combination of several risk and performance metrics in the ranking function. After applying this ranking system to select most suitable funds from a large pool, we use different models to optimize the portfolio. Past 5-10 years data set has been extracted from Bloomberg. We find out that the asymmetric multivariate t-distribution can dominate the multivariate normal distribution and the symmetric t-distribution …

Recurrence Relations For Orthogonal Polynomials For Pdes In Polar And Cylindrical Geometrics, Megan Richardson, James V. Lambers

Faculty Publications

This paper introduces two families of orthogonal polynomials on the interval (−1,1), with weight function w(x)=1. The first family satisfies the boundary condition p(1)=0, and the second one satisfies the boundary conditions p(-1)=p(1)=0. These boundary conditions arise naturally from PDEs defined on a disk with Dirichlet boundary conditions and the requirement of regularity in Cartesian coordinates. The families of orthogonal polynomials are obtained by orthogonalizing short linear combinations of Legendre polynomials that satisfy the same boundary conditions. Then, the three-term recurrence relations are derived. Finally, it is shown that from these recurrence relations, one can …

Associated Production Of A Top Pair And A W Boson At Next-To-Next-To-Leading Logarithmic Accuracy, Alessandro Broggio, Andrea Ferroglia, Giovanni Ossola, Ben D. Pecjak

Publications and Research

We consider soft gluon emission corrections to the production of a top-antitop pair in association with a W boson at the Large Hadron Collider. We obtain a soft-gluon resummation formula for this production process which is valid up to next-to-next-to-leading logarithmic accuracy. We evaluate the soft gluon resummation formula in Mellin space by means of an in-house parton level Monte Carlo code which allows us to obtain predictions for the total cross section as well as for several differential distributions. We study the impact of the soft-gluon resummation corrections in comparison to fixed order calculations.

Evaluation Of Hydrothermally Synthesized Uranium Dioxide For Novel Semiconductor Applications, Christopher M. Young

Theses and Dissertations

Neutron radiation detection is an important part of the national strategy for nonproliferation efforts worldwide. Key to the success of these programs is detector material development which establishes the limits of efficiency, sensitivity, and power usage for a detector of practical use. This research focused upon the study of neutron detection using single crystal actinide compounds, specifically UO2, taking advantage of the successful hydrothermal synthesis of UO2 at the Air Force Research Laboratories. Initial indications are that this material may be of sufficient quality for semiconductor application.

Time Domain Analysis Of Electromagnetic Scattering From Multiple Cavities Embedded In A Ground Plane, Richard P. Uber

Theses and Dissertations

This work examines the scattered fields produced when a transient wave is reflected from an infinite perfect electric conductor (PEC) ground plane with multiple embedded cavities. Incident and reflected waves will be decomposed into transverse magnetic to the z direction (TMz) and transverse electric to the z direction (TEz) polarizations, with primary focus given to the TMz. Cavities may be unfilled, partially filled, or fully filled with non-magnetic dielectric material and no assumptions are made regarding similarity, regularity, or periodicity. The Newmark method is used to discretize time and a variational formulation is presented for each time step. The principle …

Experimental Testing Of A Van De Graaff Generator As An Electromagnetic Pulse Generator, John S. Leahy

Theses and Dissertations

The purpose of this research was to evaluate an existing Van de Graaff generator facility for use as an EMP research tool. In order to assess the Van de Graaff, the unclassified Military Standard 464, which specifies a testing free field wave as having an intensity of 50 kV/m with a time-to-peak, of no more than 5 ns, was used as a baseline for free field analysis and this temporal standard used as a basis for generated currents. Unfortunately, the free field measurements were subject to substantial electronic interference from electromagnetic coupling from internal wall reflections, invalidating the assessment. Therefore …

Maximizing H-Colorings Of Connected Graphs With Fixed Minimum Degree, John Engbers

Mathematics, Statistics and Computer Science Faculty Research and Publications

No abstract provided.

High-Velocity Bipolar Molecular Emission From An Agn Torus, Jack F. Gallimore, Moshe Elitzur, Robert Maiolino, Alessandro Marconi, Christopher P. O'Dea, Dieter Lutz, Stefi A. Baum, Robert Nikutta, C. M. V. Impellizzeri, Richard Davies, Amy E. Kimball, Eleonora Sani

Physics and Astronomy Faculty Publications

We have detected in ALMA observations CO J = 6 → 5 emission from the nucleus of the Seyfert galaxy NGC 1068. The low-velocity (up to ±70 km s⁻¹ relative to systemic) CO emission resolves into a 12 × 7 pc structure, roughly aligned with the nuclear radio source. Higher-velocity emission (up to ±400 km s⁻¹) is consistent with a bipolar outflow in a direction nearly perpendicular (≃80°) to the nuclear disk. The position–velocity diagram shows that in addition to the outflow, the velocity field may also contain rotation about the disk axis. These observations provide compelling …

Mapping Spatial Distribution And Biomass Of Coastal Wetland Vegetation In Indonesian Papua By Combining Active And Passive Remotely Sensed Data, Aslan Aslan, Abdullah Rahman, Matthew W. Warren, Scott M. Robeson

School of Earth, Environmental, & Marine Sciences Faculty Publications

There is ongoing interest to develop remote sensing methods for mapping and monitoring the spatial distribution and biomass of mangroves. In this study, we develop a suite of methods to evaluate the combination of Landsat-8, ALOS PALSAR, and SRTM data for mapping spatial distribution of mangrove composition, canopy height, and aboveground biomass in the wide intertidal zones and coastal plains of Mimika district, Papua, Indonesia. Image segmentation followed by visual interpretation of composite PALSAR images was used to delineate mangrove areas, whereas a flexible statistical rule based classification of spectral signatures from Landsat-8 images was used to classify mangrove associations. …

Climate Change In Alaskan Native Communities: Lessons Learned In Adaptation And Resilience, Sarah M. Mclarnan

Forum Lectures

The Environmental Protection Agency (EPA) estimates the average temperature in Alaska has risen by 3°F in the past 60 years, over double the rate of warming in the rest of the nation. Nowhere are the consequences more severe than in rural communities. Rising temperatures have resulted in numerous threatening conditions in Alaskan Native villages such as increased rates of erosion, melting permafrost, flooding, poor air quality, severe storms, and declining access to subsistence resources. These conditions affect not only the health and safety of the community, but also traditional culture and lifestyle. This presentation covers research performed at the EPA …

Improving The Cybersecurity Of Cyber-Physical Systems Through Behavioral Game Theory And Model Checking In Practice And In Education, Seth T. Hamman

Theses and Dissertations

This dissertation presents automated methods based on behavioral game theory and model checking to improve the cybersecurity of cyber-physical systems (CPSs) and advocates teaching certain foundational principles of these methods to cybersecurity students. First, it encodes behavioral game theory's concept of level-k reasoning into an integer linear program that models a newly defined security Colonel Blotto game. This approach is designed to achieve an efficient allocation of scarce protection resources by anticipating attack allocations. A human subjects experiment based on a CPS infrastructure demonstrates its effectiveness. Next, it rigorously defines the term adversarial thinking, one of cybersecurity educations most important …

Anisotropic Cubic Curvature Couplings, Quentin G. Bailey

Publications

To complement recent work on tests of spacetime symmetry in gravity, cubic curvature couplings are studied using an effective field theory description of spacetime-symmetry breaking. The associated mass-dimension-eight coefficients for Lorentz violation studied do not result in any linearized gravity modifications and instead are revealed in the first nonlinear terms in an expansion of spacetime around a flat background. We consider effects on gravitational radiation through the energy loss of a binary system and we study two-body orbital perturbations using the post-Newtonian metric. Some effects depend on the internal structure of the source and test bodies, thereby breaking the weak …