Physical Sciences and Mathematics Commons^™

Stability Of Anisotropic Parabolic Equations Without Boundary Conditions, Huashui Zhan, Zhaosheng Feng

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

No abstract provided.

Optimal Quantization For Discrete Distributions, Russel Cabasag, Samir Huq, Eric Mendoza, Mrinal Kanti Roychowdhury

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this paper, we first determine the optimal sets of n-means and the nth quantization errors for all 1 ≤ n ≤ 6 for two nonuniform discrete distributions with support the set {1, 2, 3, 4, 5, 6}. Then, for a probability distribution P with support { 1 n : n ∈ N} associated with a mass function f, given by f(x) = 1 2k if x = 1 k for k ∈ N, and zero otherwise, we determine the optimal sets of n-means and the nth quantization errors for all positive integers up to n = 300. Further, for …

Local Well-Posedness And Blow-Up For A Family Of U(1)-Invariant Peakon Equations, Stephen C. Anco, Huijun He, Zhijun Qiao

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The Cauchy problem for a unified family of integrable U(1)-invariant peakon equations from the NLS hierarchy is studied. As main results, local well-posedness is proved in Besov spaces, and blow-up is established through use of an L 1 conservation law.

Finite Lifespan Of Solutions Of The Semilinear Wave Equation In The Einstein–De Sitter Spacetime, Anahit Galstian, Karen Yagdjian

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We examine the solutions of the semilinear wave equation, and, in particular, of the φq model of quantum field theory in the curved space-time. More exactly, for 1 < q < 4 we prove that the solution of the massless self-interacting scalar field equation in the Einstein-de Sitter universe has finite lifespan.

Solution Of The Reconstruction-Of-The-Measure Problem For Canonical Invariant Subspaces, Raul E. Curto, Sang H. Lee, Jasang Yoon

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We study the Reconstruction-of-the-Measure Problem (ROMP) for commuting 2-variable weighted shifts W(α,β), when the initial data are given as the Berger measure of the restriction of W(α,β) to a canonical invariant subspace, together with the marginal measures for the 0–th row and 0–th column in the weight diagram for W(α,β). We prove that the natural necessary conditions are indeed sufficient. When the initial data correspond to a soluble problem, we give a concrete formula for the Berger measure of W(α,β). Our strategy is to build on previous results for back-step extensions and onestep extensions. A key new theorem allows us …

Cartan’S Approach To Second Order Ordinary Differential Equations, Paul Bracken

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In his work on projective connections, Cartan discusses his theory of second order differential equations. It is the aim here to look at how a normal projective connection can be constructed and how it relates to the geometry of a single second order differential equation. The calculations are presented in some detail in order to highlight the use of gauge conditions

On The Voronoi Conjecture For Combinatorially Voronoi Parallelohedra In Dimension 5, Mathieu Dutour Sikiric, Alexey Garber, Alexander Magazinov

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In a recent paper, Garber, Gavrilyuk, and Magazinov [Discrete Comput. Geom., 53 (2015), pp. 245--260] proposed a sufficient combinatorial condition for a parallelohedron to be affinely Voronoi. We show that this condition holds for all 5-dimensional Voronoi parallelohedra. Consequently, the Voronoi conjecture in $\mathbb{R}^5$ holds if and only if every 5-dimensional parallelohedron is combinatorially Voronoi. Here, by saying that a parallelohedron $P$ is combinatorially Voronoi, we mean that $P$ is combinatorially equivalent to a Dirichlet--Voronoi polytope for some lattice $\Lambda$, and this combinatorial equivalence is naturally translated into equivalence of the tiling by copies of $P$ with …

Surviving Mathematics, Nathalie M. Luna

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

In this essay written in an informal voice, the author shares the ups and downs of her experience in academia. She shares her motivation to study mathematics, her undergraduate experience in Puerto Rico, and her graduate experience in South Texas.

Sex And Age Differences In Prevalence And Risk Factors For Prediabetes In Mexican-Americans, Kristina Vatcheva, Belinda M. Reininger, Susan P. Fisher-Hoch, Joseph B. Mccormick

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

AIMS:

Over 1/3 of Americans have prediabetes, while 9.4% have type 2 diabetes. The aim of our study was to estimate the prevalence of prediabetes in Mexican Americans, with known 28.2% prevalence of type 2 diabetes, by age and sex and to identify critical socio-demographic and clinical factors associated with prediabetes.

METHODS:

Data were collected between 2004 and 2017 from the Cameron County Hispanic Cohort in Texas. Weighted crude and sex- and age- stratified prevalences were calculated. Survey weighted logistic regression analyses were conducted to identify risk factors for prediabetes.

RESULTS:

The prevalence of prediabetes (32%) was slightly higher than …

The Global Existence Of Small Self-Interacting Scalar Field Propagating In The Contracting Universe, Anahit Galstian, Karen Yagdjian

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

We present a condition on the self-interaction term that guaranties the existence of the global in time solution of the Cauchy problem for the semilinear Klein-Gordon equation in the Friedmann-Lamaˆitre-Robertson-Walker model of the contracting universe. For the Klein- Gordon equation with the Higgs potential we give a lower estimate for the lifespan of solution.

The Quantization Of The Standard Triadic Cantor Distribution, Mrinal Kanti Roychowdhury

School of Mathematical and Statistical Sciences Faculty Publications and Presentations

The quantization scheme in probability theory deals with finding a best approximation of a given probability distribution by a probability distribution that is supported on finitely many points. For a given k ≥ 2, let {Sj : 1 ≤ j ≤ k} be a set of k contractive similarity mappings such that Sj(x) = 1 2k−1x + 2(j−1) 2k−1 for all x ∈ R, and let P = 1 k Pk j=1 P ◦ S−1 j . Then, P is a unique Borel probability measure on R such that P has support the Cantor set generated by the similarity mappings …

A Guide To Ligo–Virgo Detector Noise And Extraction Of Transient Gravitational-Wave Signals, B. P. Abbott, R. Abbott, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, Satzhan Sitmukhambetov, Robert Stone, D. Tuyenbayev, W. H. Wang, A. K. Zadrozny

Physics and Astronomy Faculty Publications and Presentations

The LIGO Scientific Collaboration and the Virgo Collaboration have cataloged eleven confidently detected gravitational-wave events during the first two observing runs of the advanced detector era. All eleven events were consistent with being from well-modeled mergers between compact stellar-mass objects: black holes or neutron stars. The data around the time of each of these events have been made publicly available through the gravitational-wave open science center. The entirety of the gravitational-wave strain data from the first and second observing runs have also now been made publicly available. There is considerable interest among the broad scientific community in understanding the data …

Electrochemically Desulfurized Molybdenum Disulfide (Mos2) And Reduced Graphene Oxide Aerogel Composites As Efficient Electrocatalysts For Hydrogen Evolution, Sanju Gupta, Taylor Robinson, N. Dimakis

Physics and Astronomy Faculty Publications and Presentations

Recent developments in graphene related materials including molybdenum disulfide (MoS₂) is gaining popularity as efficient and cost-effective nanoscale electrocatalyst essential for hydrogen production. These “clean” energy technologies require delicate control over geometric, morphological, chemical and electronic structure affecting physical and electrochemical catalytic properties. In this work, we prepared three-dimensional hierarchical mesoporous aerogels consisting of two-dimensional functionalized graphene and MoS₂ nanosheets of varying ratio of components under hydrothermal–solvothermal conditions (P <20 >bar, T <200 >°C). We systematically characterized these hybrid aerogels in terms of surface morphology, microstructure, understand heterointerfaces interaction through electron microscopy, X-ray diffraction, optical absorption and emission …

A Joint Fermi-Gbm And Ligo/Virgo Analysis Of Compact Binary Mergers From The First And Second Gravitational-Wave Observing Runs, R. Hamburg, C. Fletcher, E. Burns, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee, Volker Quetschke, Malik Rakhmanov, K. E. Ramirez, P. K. Roy, W. H. Wang, Adam Zadrozny

Physics and Astronomy Faculty Publications and Presentations

We present results from offline searches of Fermi Gamma-ray Burst Monitor (GBM) data for gamma-ray transients coincident with the compact binary coalescences observed by the gravitational-wave (GW) detectors Advanced LIGO and Advanced Virgo during their first and second observing runs. In particular, we perform follow-up for both confirmed events and low significance candidates reported in the LIGO/Virgo catalog GWTC-1. We search for temporal coincidences between these GW signals and GBM-triggered gamma-ray bursts (GRBs). We also use the GBM Untargeted and Targeted subthreshold searches to find coincident gamma-rays below the onboard triggering threshold. This work implements a refined statistical approach by …

Gw190814: Gravitational Waves From The Coalescence Of A 23 Solar Mass Black Hole With A 2.6 Solar Mass Compact Object, R. Abbott, T. D. Abbott, S. Abraham, A. Aich, G. Bissenbayeva, Teviet Creighton, Mario C. Diaz, Soma Mukherjee

Physics and Astronomy Faculty Publications and Presentations

We report the observation of a compact binary coalescence involving a 22.2 - 24.3 M⊙ black hole and a compact object with a mass of 2.50 - 2.67 M⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal, GW190814, was observed during LIGO's and Virgo's third observing run on August 14, 2019 at 21:10:39 UTC and has a signal-to-noise ratio of 25 in the three-detector network. The source was localized to 18.5 deg2 at a distance of 241+41−45 Mpc; no electromagnetic counterpart has been confirmed to date. The source has the most unequal mass ratio yet measured with …

Characterizing The Quantum Phase Transition Using A Flat Band In Circuit Qed Lattices, Gui-Lei Zhu, Xin-You Lü, Hamidreza Ramezani

Physics and Astronomy Faculty Publications and Presentations

We show the superradiant phase transition (SPT) can control the existence of flat band in an extended Dicke-Hubbard lattice [1]

Constant Intensity Conical Diffraction In Discrete One-Dimensional Lattices With Charge-Conjugation Symmetry, Mojgan Dehghani, Cem Yuce, Tsampikos Kottos, Hamidreza Ramezani

Physics and Astronomy Faculty Publications and Presentations

We engineer anomalous conical diffraction (CD), occurring in discrete one-dimensional lattices with chargeconjugation symmetry when an exceptional point is in the proximity of the modes that compose the initial excitation. The evolving waveform propagates ballistically, acquiring a constant intensity profile within the boundaries of the spreading cone. The linear increase in the total intensity along the propagation direction is responsible for the generation of constant intensity CD.

Wallaby – An Ska Pathfinder Hisurvey, B. S. Koribalski, L. Stavely-Smith, Tobias Westmeier, P. Serra, K. Spekkens, O. I. Wang, C. D. P. Lagos, D. Obreschkow, E. V. Ryan-Webber, Juan P. Madrid

Physics and Astronomy Faculty Publications and Presentations

The Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY) is a next-generation survey of neutral hydrogen (HI) in the Local Universe. It uses the widefield, high-resolution capability of the Australian Square Kilometer Array Pathfinder (ASKAP), a radio interferometer consisting of 36 x 12-m dishes equipped with Phased-Array Feeds (PAFs), located in an extremely radio-quiet zone in Western Australia. WALLABY aims to survey three-quarters of the sky (-90 degr < Dec < +30 degr) to a redshift of z < 0.26, and generate spectral line image cubes at ~30 arcsec resolution and ~1.6 mJy/beam per 4 km/s channel sensitivity. ASKAP's instantaneous field of view at 1.4 GHz, delivered by the PAF's 36 beams, is about 30 sq deg. At an integrated signal-to-noise ratio of five, WALLABY is expected to detect over half a million galaxies with a mean redshift of z ~ 0.05 (~200 Mpc). The scientific goals of WALLABY include: (a) a census of gas-rich galaxies in the vicinity of the Local Group; (b) a study of the HI properties of galaxies, groups and clusters, in particular the influence of the environment on galaxy evolution; and (c) the refinement of cosmological parameters using the spatial and redshift distribution of low-bias gas-rich galaxies. For context we provide an overview of previous large-scale HI surveys. Combined with existing and new multi-wavelength sky surveys, WALLABY will enable an exciting new generation of panchromatic studies of the Local Universe. - First results from the WALLABY pilot survey are revealed, with initial data products publicly available in the CSIRO ASKAP Science Data Archive (CASDA).

A Simple Graphical Method For Calculating The Standing Wave Frequencies On A Rectangular Membrane, Joseph D. Romano, Richard H. Price

Physics and Astronomy Faculty Publications and Presentations

In introductory physics courses, simple arguments based on traveling waves on a string are used to relate the frequency of standing waves to boundary conditions, e.g., the fixed ends of the string. Here, we extend that approach to two-dimensional waves such as the oscillations of a rectangular membrane with edges fixed at the boundary. This results in a graphical method that uses only simple geometry and is suitable for explaining two-dimensional standing-wave oscillations to non-science majors, e.g., in a physics of sound and music class.

Blockchain Based Access Control For Enterprise Blockchain Applications, Lei Xu, Isaac Markus, Subhod I, Nikhil Nayab

Computer Science Faculty Publications and Presentations

Access control is one of the fundamental security mechanisms of IT systems. Most existing access control schemes rely on a centralized party to manage and enforce access control policies. As blockchain technologies, especially permissioned networks, find more applicability beyond cryptocurrencies in enterprise solutions, it is expected that the security requirements will increase. Therefore, it is necessary to develop an access control system that works in a decentralized environment without compromising the unique features of a blockchain. A straightforward method to support access control is to deploy a firewall in front of the enterprise blockchain application. However, this approach does not …

How To Promote Education For Sustainable Development? Vision Of The Educational Situation And Its Contribution To Sustainable Development., Khalid Aada

Writing and Language Studies Faculty Publications and Presentations

During the last decade, the importance of leaving a rational paradigm, debtor of functionalist and utilitarian models, towards another more congruent with the preservation of natural resources, and therefore of life, has been widely discussed. In the same way, different voices have been raised, pointing out the urgency of inserting these precepts into the educational field, hoping to achieve the true cultural transformation that is needed to consolidate the change. Multiple International Entities promote sustainability in Education as an initiative that should be ambitious, complex and reforming character, given the global scope of the social, economic and environmental situation affecting …

Quantum-Enhanced Advanced Ligo Detectors In The Era Of Gravitational-Wave Astronomy, M. Tse, Haocun Yu, N. Kijbunchoo, A. Fernandez-Galiana, P. Dupej, L. Barsotti, C. D. Blair, D. D. Brown, S. E. Dwyer, Karla E. Ramirez

Physics and Astronomy Faculty Publications and Presentations

The Laser Interferometer Gravitational Wave Observatory (LIGO) has been directly detecting gravitational waves from compact binary mergers since 2015. We report on the first use of squeezed vacuum states in the direct measurement of gravitational waves with the Advanced LIGO H1 and L1 detectors. This achievement is the culmination of decades of research to implement squeezed states in gravitational-wave detectors. During the ongoing O3 observation run, squeezed states are improving the sensitivity of the LIGO interferometers to signals above 50 Hz by up to 3 dB, thereby increasing the expected detection rate by 40% (H1) and 50% (L1).

Kcrs: A Blockchain-Based Key Compromise Resilient Signature System, Lei Xu, Lin Chen, Zhimin Gao, Xinxin Fan, Kimberly Doan, Shouhuai Xu, Weidong Shi

Computer Science Faculty Publications and Presentations

Digital signatures are widely used to assure authenticity and integrity of messages (including blockchain transactions). This assurance is based on assumption that the private signing key is kept secret, which may be exposed or compromised without being detected in the real world. Many schemes have been proposed to mitigate this problem, but most schemes are not compatible with widely used digital signature standards and do not help detect private key exposures. In this paper, we propose a Key Compromise Resilient Signature (KCRS) system, which leverages blockchain to detect key compromises and mitigate the consequences. Our solution keeps a log of …

Energy And Exergy Analysis Of A Novel Multiple-Effect Vapor Chamber Distillation System For High-Salinity Wastewater Treatment, Hamidreza Shabgard, Ramkumar Parthasarathy, Ben Xu

Mechanical Engineering Faculty Publications and Presentations

A novel modular thermally-driven multiple-effect vapor chamber distillation (MVCD) system is presented for compact and portable desalination applications. The MVCD system consists of several vapor chambers connected in series with the condenser section of the upstream vapor chambers serving as the evaporator section of the following effect. A heat transfer model accounting for the major thermal resistances was developed to predict the heat transfer and distilled water production rates. A mass transfer analysis was performed to evaluate the effect of the accumulation of the non-condensable gasses within the chambers. An exergy analysis was also conducted to quantify the efficiency of …

The Role Of Sediment Resuspension In Estuarine Inorganic Nutrient Cycling, Kirsten Jo Ayres

Theses and Dissertations

Time-scaling of estuarine inorganic nitrogen cycling contains many assumptions due to biogeochemical interactions. Nitrogen, often a limiting factor for primary production, is transformed and utilized by many estuarine organisms. Inorganic nitrogen is especially high in porewater. High nutrient pore water, contained within the interstitial spaces of sediment, has been assumed to influx high concentrations of inorganic nutrients into surface waters during resuspension events. These short-term resuspension events rapidly introducing high concentration of nutrients into the water column. In order to determine the internal time scale of inorganic nitrogen cycling, a box-model nutrient budget, horizontal in situ transects, and vertical nutrient …

Constructing Associative Rings From Certain Hypergroups, Oscar Gonzalez

Theses and Dissertations

Tight hypergroups give rise to associative rings if the so-called general normality condition holds\cite{ARTICLE:1}. We consider four examples of tight hypergroups which do not satisfy the general normality condition and show that they still give rise to associative rings. Our examples are HM332(24),HM10353(32), HM10933(32) and HM10941(32)[1].

Histological Evidence Of Annual And Lunar Reproductive Rhythms Of Atlantic Sea Urchin, Arbacia Punctulata In The Gulf Of Mexico: Changes In Nutritive Phagocytes In Relation To Gametogenesis, Eleazar Hernandez Ii

Theses and Dissertations

Environmental phenomena such as temperature, photoperiod, tidal cycle, and lunar rhythm act as external cues that stimulate the reproductive activity of marine organisms. In this study, I report the annual and lunar reproductive cycles, and changes in nutritive phagocytes (NPs) in relation to gonadal maturation of Atlantic sea urchin (Arbacia punctulata, a primeval species). Monthly and weekly changes in gonadal development/maturation were observed histologically. In male, the testicular lobules were densely packed with sperm from June to August. In female, on the other hand, mature eggs first appeared in some ovaries in May, numerically increased from June to …

Predation Of Eastern Cottontail Rabbit (Sylvilagus Floridanus) By Great Blue Heron (Ardea Herodias), Carlos E. Cintra-Buenrostro, J. E. Cifuentes-Lujan

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

An opportunistic predation by Great Blue Heron (Ardea herodias) on Eastern cottontail rabbit (Sylvilagus floridanus) was observed in south Texas on 31 Oct 2019. The Great Blue Heron had already captured the Eastern cottontail rabbit at the first observation but the maneuvering process, killing, and ingestion were recorded photographically, which make this observation unique even though this might constitute the second report on Great Blue Heron eating Eastern cottontail rabbits.

Production Of Biscuits By Substitution With Different Ratios Of Yellow Pea Flour, Jikai Zhao, Xin Liu, Xiang Bai, Fengcheng Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

To promote the commercialization of yellow pea flour (YPF) due to its nutritional benefits. Four biscuits with different YPF ratio (10%–50%) were conducted to explore the optimal addition percentage. The effects of YPF on the rheological and baking performance of biscuits were performed. The results showed that the substitution ratio of YPF and milling methods had a critical impact on the rheological properties of dough. The dough stability decreased gradually while a softening degree increased with YPF ratio increased. In a term of biscuits, the dimensions of length (L), width (W), thickness (T) and color (L*) of biscuits reduced as …

Enabling High Quality Oxygen Measurements During Robotic Based Studies Of Ocean Ecological And Biogeochemical Processes, Brianna A. Alanis

Theses and Dissertations

Dissolved oxygen is an essential parameter necessary for understanding marine ecological and biogeochemical processes. New robotic vehicles and autonomous platforms are being applied to an even wider range of ecological and biogeochemical studies. Thus, arises the opportunity for matching the best possible oxygen sensing techniques and methods to these new platforms. In so doing, we can enable both more targeted and higher resolution oxygen measurements than previously possible and potentially use oxygen measurements for a wider range of applications, including in situ incubation experiments and primary productivity measurements. This thesis tested three different oxygen sensors in a trade study for …