Physical Sciences and Mathematics Commons^™

Amplification Of Hidden Periodic Motions In 3d Videos, Thomas Boccuto, Seraiah Kutai, Kristen Mosley, Samuel Kirk

Mathematics Summer Fellows

Ordinary videos capture a surprising amount of hidden, visually imperceptible information. For instance, videos of peoples' faces may capture color changes in the skin and artery motion from heartbeats, while videos of mechanical systems can capture subtle vibrations indicating imminent failure. Algorithms can extract and exaggerate these signals for visualization on top of the original videos. In particular, Eulerian magnification algorithms sidestep the need to track hidden motions directly and instead devise multiscale bandpass filters to amplify signals in local spatial regions. In this work, we extend these techniques beyond color videos to geometric video data captured by 3D depth …

Computational Studies Of Carbon Nanocluster Solidification, Chathuri C. Silva

Dissertations

A subset of micron-size meteoritic carbon particles formed in red giant atmospheres show a core-rim structure, likely condensed from a vapor phase into super-cooled carbon droplets that nucleated graphene sheets (~40Å) on randomly oriented 5-atom loops during solidification, followed by coating with a graphite rim. Similar particles form during slow cooling of carbon vapor in the lab.

Here we investigate the nucleation and growth of carbon rings and graphene sheets using density functional theory (DFT). Our objectives: (1). explore different computational techniques in DFT-VASP for various carbon structures and compare the results with literature, (2). investigate the nucleation and growth …

Impacts Of Wildfire And Landscape Factors On Organic Soil Properties In Arctic Tussock Tundra, Jiaying He, Dong Chen, Liza K. Jenkins, Tatiana V. Loboda

Michigan Tech Publications

Tundra ecosystems contain some of the largest stores of soil organic carbon among all biomes worldwide. Wildfire, the primary disturbance agent in Arctic tundra, is likely to impact soil properties in ways that enable carbon release and modify ecosystem functioning more broadly through impacts on organic soils, based on evidence from a recent extreme Anaktuvuk River Fire (ARF). However, comparatively little is known about the long-term impacts of typical tundra fires that are short-lived and transient. Here we quantitatively investigated how these transient tundra fires and other landscape factors affected organic soil properties, including soil organic layer (SOL) thickness, soil …

Urban Forests And Their Potential To Combat Food Insecurity: Analyzing Street Trees In Baltimore, Md For Their Edibility, Victoria Bearden

Environment and Sustainability Summer Fellows

Food insecure environments, in which residents lack consistent access to nutritious food materials, can occur in urban settings. Literature on urban forests suggests that trees can provide a range of provisioning ecosystem services, including edible uses. We consider this to determine if street trees in Baltimore, Maryland have the potential to provide nutritious food materials to address food insecurity in Healthy Food Priority Areas (HFPA), designated by Johns Hopkins Center for a Livable Future.

Urban Forests And Their Potential To Combat Food Insecurity: Analyzing Foods From Street Trees In New York City, Ny, Kristen Cooney

Environment and Sustainability Summer Fellows

There is growing recognition that urban forests have the potential to combat food insecurity via their edible parts, namely fruits, berries, and nuts. Many tree species commonly planted in urban spaces have edible parts that may fulfill the nutritional needs of city residents that are food insecure, but no one has analyzed the value of city street trees to understand this potential. I analyzed New York City’s street trees by each species and their edible parts to measure this potential.

Rezina Shams – The First Known Woman Geologist From Dhaka University (Bangladesh) To Obtain A Phd, Nazrul I. Khandaker

Publications and Research

Rezina Shams (Dhaka University geology graduate 1985; née Rezina Bashar) is the first known female geologist from Bangladesh to obtain a PhD in 1991 (University of Birmingham, UK). Rezina’s undergraduate and graduate education in geology at Dhaka University (DU) was at a time when only a handful of female students attended the program. Rezina’s debut into her geology career began with the Master Plan Organisation (MPO) and then the Bangladesh Atomic Energy Commission (1986). Rezina kept her aspirations alive, and eventually furthered her geoscience education to a PhD. Upon receiving a PhD in 1991 from the University of Birmingham under …

Riemann-Hilbert Problems For Nonlocal Reverse-Time Nonlinear Second-Order And Fourth-Order Akns Systems Of Multiple Components And Exact Soliton Solutions, Alle Adjiri

USF Tampa Graduate Theses and Dissertations

We first investigate the solvability of an integrable nonlinear nonlocal reverse-time six-component fourth-order AKNS system generated from a reduced coupled AKNS hierarchy under a reverse-time reduction. Riemann-Hilbert problems will be formulated by using the associated matrix spectral problems, and exact soliton solutions will be derived from the reflectionless case corresponding to an identity jump matrix. Secondly, we present the inverse scattering transform for solving a class of eight-component AKNS integrable equations obtained by a specific reduction associated with a block matrix spectral problem. The inverse scattering transform based on Riemann-Hilbert problems is presented along with a jump matrix taken to …

Upper Limits On The Isotropic Gravitational-Wave Background From Advanced Ligo And Advanced Virgo's Third Observing Run, R. Abbott, T. D. Abbott, S. Abraham, F. Acernese, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Karla E. Ramirez, W. H. Wang

Physics and Astronomy Faculty Publications and Presentations

We report results of a search for an isotropic gravitational-wave background (GWB) using data from Advanced LIGO’s and Advanced Virgo’s third observing run (O3) combined with upper limits from the earlier O1 and O2 runs. Unlike in previous observing runs in the advanced detector era, we include Virgo in the search for the GWB. The results of the search are consistent with uncorrelated noise, and therefore we place upper limits on the strength of the GWB. We find that the dimensionless energy density ΩGW≤5.8×10−9 at the 95% credible level for a flat (frequency-independent) GWB, using a prior which is uniform …

Treatment Patterns And Outcomes In Elderly Patients With Newly Diagnosed Multiple Myeloma: Results From The Connect® Mm Registry, Hans C. Lee, Sikander Ailawadhi, Cristina J. Gasparetto, Sundar Jagannath, Robert M. Rifkin, Brian G.M. Durie, Mohit Narang, Howard R. Terebelo, Kathleen Toomey, James W. Hardin Ph.D., Lynne Wagner, James L. Omel, Mazaher Dhalla, Liang Liu, Prashant Joshi, Rafat Abonour

Faculty Publications

No abstract provided.

Advancement In Infrared Optics Through The Exploration Of Solution Derived Arsenic Selenide (As2se3) Thin Films, Annabella Orsini

Physics and Astronomy Summer Fellows

There are great opportunities for advancement in the realm of infrared (IR) optics through the use of chalcogenide glasses (ChGs). The development of IR optics using ChGs is important for applications in search and rescue operations, firefighting efforts, medical imaging, and satellites. Instead of creating bulky, expensive, single crystal IR glasses, ChGs can be deposited as thin films by solution derived (SD) spin or dip coating. Our research takes a multidisciplinary approach to investigate ChGs thin films using physics, chemistry, optics, and materials science.

The Analysis Of Ginsenosides In Ginseng Garden Soil, Karina Marie Kaberi

Electronic Thesis and Dissertation Repository

American ginseng (Panax quinquefolius L.) produces natural products called ginsenosides. The biggest challenge Ontario commercial ginseng farmers face is ginseng replant disease. To understand the function of ginseng root exudates, ginsenoside accumulation and persistence over time were investigated. Currently, no reliable ginsenoside specific extraction method, characterizing the changes in soil chemistry exists. Ginsenoside extraction protocol optimization was required to determine how ginsenoside composition changed over time. Overall, protocol optimization resulted in a 30% increase in yield of ginsenosides compared to previous extraction protocols. In the ginseng gardens, ginsenoside accumulation occurs slowly and did not reach significantly measurable amounts until the …

The Fatty Acid Profile Of Traditional Home‐Made Kurut In Xinjiang Pastoral Regions, Yimamu Aibibula, Masaaki Hanada, M. Hirata, M. Renaguli, M. Goto

IGC Proceedings (1993-2023)

No abstract provided.

Multiple‐Use Grasslands: Integrating Forage, Biofuel, And Carbon/Phosphorus Sinks, James P. Muir, B. Lambert, G. W. Evers, T. J. Butler, K. F. Bronson, L. Stanley‐Stevens, R. D. Wittie

IGC Proceedings (1993-2023)

No abstract provided.

Producing Biofuels With Alternative Fertilizers: A Comparison Of Two Promising Species, Mari‐Vaughn V. Johnson, James R. Kiniry

IGC Proceedings (1993-2023)

No abstract provided.

Biorenewable Energy: New Opportunities For Grassland Agriculture, Kenneth J. Moore, Steven L. Fales, Emily A. Heaton

IGC Proceedings (1993-2023)

No abstract provided.

Multiple Use Management On Canadian Publicly Managed Rangeland, B. Kirychuk, R. Gaube, S. Kushreshtha, G. Pearson

IGC Proceedings (1993-2023)

No abstract provided.

54fe(D,P)55fe Single Neutron Transfer Presentation, Matthew Quirin, Raymond Saunders

Physics and Astronomy Presentations

During our summer research at the John D Fox Laboratory, we used the 9 MV Tandem van de Graaff accelerator and the Super Enge Split-Pole Spectrograph to make measurements of the neutron transfer reaction 54Fe(d,p) 55Fe to observe and explore excited states of 55Fe and shell structure beyond the magic number N=28. We have created momentum spectra and angular distribution plots of the protons from the reaction which will be analyzed to determine the angular momentum values of states and single-neutron energies in 55Fe in an effort to better understand nuclear structure.

Threshold Concepts In Web Development: The Impact Of Education And Experience On The Perceptions Of Practitioners, Michael Lee Mick

College of Computing and Digital Media Dissertations

The Threshold Concepts (TCs) framework posits characteristics of critical concepts that enable a learner to see things in a new and unforgettable way that allows the incorporation of cognitive approaches and skills needed by professionals in the discipline. All previous research has been qualitatively oriented toward discovery of candidate TCs, without, so far, quantitative studies of the candidate TCs recognition within the professional ranks. An underrepresented group in previous research is that of Web development professionals.

This proposal describes initial quantitative research utilizing the TCs framework in the Web development area to measure the perception of candidate TCs by professionals …

Essays In Behavioral Social Choice Theory., Sarvesh Bandhu Dr.

Doctoral Theses

This thesis comprises four essays on social choice theory. The first three essays/chapters consider models where voters follow “non-standard” rules for decision making. The last chapter considers the binary social choice model and analyzes the consequences of a new axiom. The first chapter introduces a new axiom for manipulability when voters incur a cost if they misreport their true preference ordering. The second chapter considers the random voting model with strategic voters where standard stochastic dominance strategy-proofness is replaced by strategy-proofness under two lexicographic criteria. The third chapter also considers the random voting model but from a non-strategic perspective. It …

Near-Optimal Learning Of Tree-Structured Distributions By Chow-Liu, Arnab Bhattacharyya, Sutanu Gayen, Eric Price, N. V. Vinodchandran

Department of Mathematics: Faculty Publications

We provide finite sample guarantees for the classical Chow-Liu algorithm (IEEE Trans. Inform. Theory, 1968) to learn a tree-structured graphical model of a distribution. For a distribution P on Σⁿ and a tree T on n nodes, we say T is an ε-approximate tree for P if there is a T-structured distribution Q such that D(P || Q) is at most ε more than the best possible tree-structured distribution for P. We show that if P itself is tree-structured, then the Chow-Liu algorithm with the plug-in estimator for mutual information with eO (|Σ| …

Bridging The 12-6-4 Model And The Fluctuating Charge Model, Pengfei Li

Chemistry: Faculty Publications and Other Works

Metal ions play important roles in various biological systems. Molecular dynamics (MD) using classical force field has become a popular research tool to study biological systems at the atomic level. However, meaningful MD simulations require reliable models and parameters. Previously we showed that the 12-6 Lennard-Jones nonbonded model for ions could not reproduce the experimental hydration free energy (HFE) and ion-oxygen distance (IOD) values simultaneously when ion has a charge of +2 or higher. We discussed that this deficiency arises from the overlook of the ion-induced dipole interaction in the 12-6 model, and this term is proportional to 1/r …

Desorption Of Non-Exchangeable Radiocesium In Soil From Fukushima Prefecture, Japan, Grayson Phillips

Master of Science in Chemical Sciences Theses

The Fukushima Daiichi Nuclear Powerplant was struck by an earthquake and a tsunami resulting in the meltdown of four of the six reactor cores operating at the plant. As a result, nuclear waste was released from the plant, contaminating the soil in the region. Most of the contamination was sequestered within the few inches of the soil but unluckily the contamination, radiocesium formed a non-exchangeable bond. The Japanese government bagged this soil and has stored it in fields surrounding the exclusion zone. Long-term storage facilities have not been determined. This is a study of the available resources to determine if, …

Study Of The Effects Of Cavity Mode Spacing On Mode-Hopping In Iii–V/Si Hybrid Photonic Crystal Lasers, Praveen K.J. Singaravelu, Sharon M. Butler, Robert N. Sheehan, Alexandros A. Liles, Stephen P. Hegarty, Liam O'Faolain

Cappa Publications

We present a design methodology for hybrid lasers to realise mode-hop free operation by controlling the cavity mode spacing. In this study, a compact hybrid photonic crystal laser (H-PhCL) was employed which allowed a reduction of the Fabry–Perot length of the laser cavity and eliminated the need for an active mode stabilisation mechanism in order to realise mode-hop free operation. The H-PhCL was formed by butt-coupling a reflective semiconductor optical amplifier (RSOA) with a two-dimensional silicon (Si) photonic crystal (PhC) cavity. Continuous stable single frequency operation with >40 dB side-mode suppression ratio (SMSR) of the laser was achieved for gain …

Torsional Profiles Of Thiophene And Furan Oligomers: Probing The Effects Of Heterogeneity And Chain Length, Morgan A. Perkins, Laura M. Cline, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

A systematic analysis of the torsional profiles of 55 unique oligomers composed of two to four thiophene and/or furan rings (n = 2 to 4) has been conducted using three density functional theory (DFT) methods along with MP2 and three different coupled-cluster methods. Two planar or quasi-planar minima were identified for each n = 2 oligomer system. In every case, the torsional angle (τ) between the heteroatoms about the carbon-carbon bond connecting the two rings is at or near 180° for the global minimum and 0° for the local minimum, referred to as anti and syn conformations, respectively. These oligomers …

54fe(D,P)55fe Single Neutron Transfer, Matthew Quirin, Raymond Saunders

Physics and Astronomy Summer Fellows

During our summer research at the John D Fox Laboratory, we used the 9 MV Tandem van de Graaff accelerator and the Super Enge Split-Pole Spectrograph to make measurements of the neutron transfer reaction 54Fe(d,p) 55Fe to observe and explore excited states of 55Fe and shell structure beyond the magic number N=28. We have created momentum spectra and angular distribution plots of the protons from the reaction which will be analyzed to determine the angular momentum values of states and single-neutron energies in 55Fe in an effort to better understand nuclear structure.

Algorithms Related To Triangle Groups, Bao The Pham

LSU Doctoral Dissertations

Given a finite index subgroup of $\PSL_2(\Z)$, one can talk about the different properties of this subgroup. These properties have been studied extensively in an attempt to classify these subgroups. Tim Hsu created an algorithm to determine whether a subgroup is a congruence subgroup by using permutations \cite{hsu}. Lang, Lim, and Tan also created an algorithm to determine if a subgroup is a congruence subgroup by using Farey Symbols \cite{llt}. Sebbar classified torsion-free congruence subgroups of genus 0 \cite{sebbar}. Pauli and Cummins computed and tabulated all congruence subgroups of genus less than 24 \cite{ps}. However, there are still some problems …

Causes And Characteristics Of Electrical Resistivity Variability In Shallow (<4 M) Soils In Taylor Valley, East Antarctica, William S. Gutterman

LSU Master's Theses

The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are characterized as a polar desert environment. Soils in the region are typically very dry (<1% soil water by weight) and remain frozen for most of the year. Increases in air temperature and incoming solar radiation during the austral summer generate meltwater from glaciers, ground ice, and snow patches supplying moisture to soils and altering the physical and chemical makeup of the subsurface. Previous studies have utilized airborne electromagnetic surveys (AEM) to analyze groundwater systems in the deep subsurface but have not yet examined soil moisture in the shallow (<4 m) subsurface. Here, I used electrical resistivity data from two AEM surveys (2011 and 2018) and soil geochemical data from three transects to characterize the spatial heterogeneity of soil properties in the near-subsurface of lower Taylor Valley. Soil resistivities from 2011 and 2018 range from 33.2 Ωm to 3535 Ωm with low elevations of <100 meters above sea level (masl) typically displaying the lowest resistivities and high elevations displaying greater resistivities. Liquid brine fractions were empirically estimated from electrical resistivity values using Archie’s Law and range from 0.3% to 68.2% for soils with resistivities <200 Ωm. Additionally, soil transect data show greater percentages of fine-grained sediments (<63 µm) exist at elevations <100 masl where soil resistivities begin decreasing. Resistivity variability in the subsurface is ultimately controlled by the site history, local and regional climate, soil salinity, soil moisture, soil lithology.

Designing Land Taxes To Promote Conservation Through Use Of Rangelands: Bio‐Economic Modeling Of Farm Decision‐Making In Southern Namibia, Stephanie E. Domptail, Ernst‐August Nuppenau

IGC Proceedings (1993-2023)

No abstract provided.

Mobility And Development: Iranian Perspective, Hossein Badripour

IGC Proceedings (1993-2023)

No abstract provided.

Survey Of The Advanced Development Of Pastoral Education In Xilin Gol League, Yunhua Zhang

IGC Proceedings (1993-2023)

No abstract provided.