Digital Commons Network^™

Homotopy Groups And Quantitative Sperner-Type Lemma, Oleg R. Musin

School of Mathematical & Statistical Sciences Faculty Publications

We consider a generalization of Sperner's lemma for triangulations of m-discs whose vertices are colored in at most m colors. A coloring on the boundary (m-1)-sphere defines an element in the corresponding homotopy group of the sphere. Depending on this invariant, a lower bound is obtained for the number of fully colored simplexes. In particular, if the Hopf invariant is nonzero on the boundary of 4-disk, then there are at least 9 fully colored tetrahedra and if the Hopf invariant is d, then the lower bound is 3d + 3.

Concrete Polytopes May Not Tile The Space, Alexey Garber, Igor Pak

School of Mathematical & Statistical Sciences Faculty Publications

Brandolini et al. conjectured in (Preprint, 2019) that all concrete lattice polytopes can multitile the space. We disprove this conjecture in a strong form, by constructing an infinite family of counterexamples in ℝ3 .

Weak Mitoticity Of Bounded Disjunctive And Conjunctive Truth-Table Autoreducible Sets, Liyu Zhang, Mahmoud K. Quweider, Hangsheng Lei, Fitratullah Khan

Computer Science Faculty Publications

Glaßer et al. (SIAMJCOMP 2008 and TCS 2009)2 proved existence of two sparse sets A and B in EXP, where A is 3-tt (truth-table) polynomial-time autoreducible but not weakly polynomial-time Turing mitotic and B is polynomial-time 2-tt autoreducible but not weakly polynomial-time 2-tt mitotic. We unify and strengthen both of those results by showing that there is a sparse set in EXP that is polynomial-time 2-tt autoreducible but not even weakly polynomial-time Turing mitotic. All these results indicate that polynomial-time autoreducibilities in general do not imply polynomial-time mitoticity at all with the only exceptions of the many-one and 1-tt reductions. …

Infusing Raspberry Pi In The Computer Science Curriculum For Enhanced Learning, Fitratullah Khan, Mahmoud K. Quweider, Ala Qubbaj, Emmett Tomai, Lei Xu, Liyu Zhang, Hansheng Lei

Computer Science Faculty Publications

With the advent of cloud computing, the Internet of Things (IoT), and mobile computing, CS faculty are continuously revamping the curriculum material to address such burgeoning set of technologies in practical and relatable ways. Raspberry Pi (RPi) devices represent an ideal hardware/software framework that embodies all these technologies through its simple architecture, small form factor (that minimizes the volume and footprint of a desktop computer), and ability to integrate various sensors that network together and connect to the Cloud. Therefore, one of the strategies of Computer Science Department, to enhance depth of learning concepts, has been to infuse Raspberry Pi …

Burnside Chromatic Polynomials Of Group-Invariant Graphs, Jacob A. White

School of Mathematical & Statistical Sciences Faculty Publications

We introduce the Burnside chromatic polynomial of a graph that is invariant under a group action. This is a generalization of the Q-chromatic function Zaslavsky introduced for gain graphs. Given a group G acting on a graph G and a G-set X, a proper X-coloring is a function with no monochromatic edge orbit. The set of proper colorings is a G-set which induces a polynomial function from the Burnside ring of G to itself. In this paper, we study many properties of the Burnside chromatic polynomial, answering some questions of Zaslavsky

Benchmarking And Parameter Sensitivity Of Physiological And Vegetation Dynamics Using The Functionally Assembled Terrestrial Ecosystem Simulator (Fates) At Barro Colorado Island, Panama, Charles D. Koven, Ryan G. Knox, Rosie A. Fisher, Jeffrey Q. Chambers, Bradley O. Christoffersen, Stuart J. Davies, Matteo Detto

School of Earth, Environmental, & Marine Sciences Faculty Publications

Plant functional traits determine vegetation responses to environmental variation, but variation in trait values is large, even within a single site. Likewise, uncertainty in how these traits map to Earth system feedbacks is large. We use a vegetation demographic model (VDM), the Functionally Assembled Terrestrial Ecosystem Simulator (FATES), to explore parameter sensitivity of model predictions, and comparison to observations, at a tropical forest site: Barro Colorado Island in Panama. We define a single 12-dimensional distribution of plant trait variation, derived primarily from observations in Panama, and define plant functional types (PFTs) as random draws from this distribution. We compare several …

Alternatively Assessing Conceptual Learning In An Emergency Clinical Environment—A Mixed Methods Design, Zhidong Zhang, Alice Yang Zhang

Teaching and Learning Faculty Publications

Modeling cognitive processes in clinical learning environments is a necessary first step towards improving learning assessment and medical practice by using an alternative assessment model. Verbal protocol and cognitive content analyses are effective methods of exploring such cognitive processes. For the purpose of simplifying the discussion, we have labeled these processes as Identification of Information, Advanced Cognition, and Medical Cognitive Action. Exploring problem solving processes with Bayesian network techniques can characterize students' dynamic learning processes quantitatively, identify differences in cognitive components at different stages of learning and better represent clinical problem solving features.

We develop a hierarchical cognitive model as …

Characterizing Quantum Physics Students’ Conceptual And Procedural Knowledge Of The Characteristic Equation, Kaitlyn Stephens Serbin, Brigitte Johana Sánchez Robayo, Julia Victoria Truman, Kevin Lee Watson, Megan Wawro

School of Mathematical & Statistical Sciences Faculty Publications

Research on student understanding of eigentheory in linear algebra has expanded recently, yet few studies address student understanding of the Characteristic Equation. In this study, we explore quantum physics students’ conceptual and procedural knowledge of deriving and using the Characteristic Equation. We developed the Conceptual and Procedural Knowledge framework for classifying the quality of students’ conceptual and procedural knowledge of both deriving and using the Characteristic Equation along a continuum. Most students exhibited deeper conceptual and procedural knowledge of using the Characteristic Equation than of deriving the Characteristic Equation. Furthermore, most students demonstrated deeper procedural knowledge than conceptual knowledge of …

Potential Predictability Of Net Primary Production In The Ocean, Kristen M. Krumhardt, Nicole S. Lovenduski, Matthew C. Long, J. Y. Luo, K. Lindsay, S. Yeager, Cheryl S. Harrison

School of Earth, Environmental, & Marine Sciences Faculty Publications

Interannual variations in marine net primary production (NPP) contribute to the variability of available living marine resources, as well as influence critical carbon cycle processes. Here we provide a global overview of near-term (1 to 10 years) potential predictability of marine NPP using a novel set of initialized retrospective decadal forecasts from an Earth System Model. Interannual variations in marine NPP are potentially predictable in many areas of the ocean 1 to 3 years in advance, from temperate waters to the tropics, showing a substantial improvement over a simple persistence forecast. However, some regions, such as the subpolar Southern Ocean, …

Effect Of Pecan Variety And The Method Of Extraction On The Antimicrobial Activity Of Pecan Shell Extracts Against Different Foodborne Pathogens And Their Efficacy On Food Matrices, Veerachandra K. Yemmireddy, Cameron Cason, Juan Moreira, Achyut Adhikari

School of Earth, Environmental, & Marine Sciences Faculty Publications

The shells of pecans are a rich source of bioactive compounds with potential inhibitory activity against various pathogenic microorganisms. This study investigated the antimicrobial activity of pecan shell extracts as effected by the type of cultivar and the method of extraction against various foodborne bacterial pathogens. Defatted shell powders of 19 different pecan cultivars were subjected to aqueous and ethanolic extraction (1:20 w/v) procedures, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of lyophilized pecan shell extracts dissolved in deionized water containing 5% DMSO (v/v) were determined against multiple strains of Listeria monocytogenes, Salmonella enterica, and …

Cybersecurity, Digital Forensics, And Mobile Computing: Building The Pipeline Of Next-Generation University Graduates Through Focused High School Summer Camps, Mahmoud K. Quweider, Fitratullah Khan, Liyu Zhang, Lei Xu, Yessica Rodriguez, Yessenia Rodriguez

Computer Science Faculty Publications

To prepare the next generation of skilled university graduates that would help in filling the national need for cybersecurity, digital forensics, and mobile computing professionals, a team of minority/under-represented graduate students, the University Upward Bound Program (a federally funded program and part of the U.S. Department of Education; one of 967 programs nationwide) staff, and faculty from the Computer Science (CS) department got together and proposed a focused 10-week long funded summer camp for two local high schools with the following objectives:

1. Provide graduate students to instruct in the areas of` mobile application development, forensics and cyber Security.

2. …

Categorizing Zonal Productivity On The Continental Shelf With Nutrient-Salinity Ratios, Jongsun Kim, Piers Chapman, Gilbert Rowe, Steven F. Dimarco

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

• Identifying riverine influence on productivity in the northern Gulf of Mexico
• Use of nutrient/salinity plots to differentiate inputs from two rivers
• Verifying Rowe-Chapman (2002) hypothesis with in situ data

Abstract

Coastal ocean productivity is often dependent on riverine sources of nutrients, yet it can be difficult to determine how far the influence of the river extends. The northern Gulf of Mexico (GOM) receives freshwater and nutrients discharged mainly from the Mississippi and Atchafalaya Rivers. We used nutrient/salinity relationships to (i) differentiate the nutrient inputs of the two rivers and (ii) determine the potential extent of the zones where productivity …

Visual Attention Consistency Under Image Transforms For Multi-Label Image Classification, Hao Guo, Kang Zheng, Xiaochuan Fan, Hongkai Yu, Song Wang

Computer Science Faculty Publications

Human visual perception shows good consistency for many multi-label image classification tasks under certain spatial transforms, such as scaling, rotation, flipping and translation. This has motivated the data augmentation strategy widely used in CNN classifier training -- transformed images are included for training by assuming the same class labels as their original images. In this paper, we further propose the assumption of perceptual consistency of visual attention regions for classification under such transforms, i.e., the attention region for a classification follows the same transform if the input image is spatially transformed. While the attention regions of CNN classifiers can be …

The Role Of Α, Γ, And Metastable Polymorphs On Electrospun Polyamide 6/Functionalized Graphene Oxide, Javier Macossay-Torres, Yazmin I. Avila-Vega, Faheem A. Sheikh, Travis Cantu, Francisco E. Longoria-Rodriguez, Edgar H. Ramirez-Soria, Rigoberto C. Advincula, Jose Bonilla-Cruz

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The present paper describes the addition of nitroxide-functionalized graphene oxide (GOFT) into polyamide 6 (PA6) micro- and nanofibers, which were obtained through electrospinning. SEM micrographs demonstrated the presence of fibers. Tensile testing presented an unexpected and non-obvious behavior, in which the Young’s modulus, tensile strength, and elongation simultaneously and remarkably increased compared to the pristine polymer nanofibers. GOFT induces the hydrogen bonding between the NH group from PA6 with the functional groups, thus promoting higher crystallinity of the polymer matrix. Nonetheless, deconvoluted DSC curves revealed the presence of two quasi-steady polymorphous (b and d phases) contributing to 46% of the …

Effect Of Hydrothermal Temperature Treatment On The Variance Of Fluorescence In Ca2sio4:Tb3Þ, Rajaboopathi Mani, Santosh K. Gupta

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Investigations of structural defects and their associated impact on the optical properties of optical materials are essential expediencies because different methods are involved in the preparation of those materials for display applications. Lanthanide ion doping is a simple structural probing strategy that facilitates the challenges of identifying the structural defects. Pure and terbium (Tb3+) doped Ca2SiO4 (C2S) particles were prepared using Pechini (C2SP) and hydrothermal methods (C2SH). From SEM images, it is observed that the Tb3+ doped C2SP particles were highly agglomerated, more than the C2SH particles. The TEM study confirmed that the particle size decreased for C2SH prepared at …

Level 17 Ramanujan-Sato Series, Timothy Huber, Daniel Schultz, Dongxi Ye

School of Mathematical & Statistical Sciences Faculty Publications

Two level 17 modular functions r=q2∏n=1∞(1−qn)(n17),s=q2∏n=1∞(1−q17n)3(1−qn)3 are used to construct a new class of Ramanujan–Sato series for 1/π. The expansions are induced by modular identities similar to those level of 5 and 13 appearing in Ramanujan’s Notebooks. A complete list of rational and quadratic series corresponding to singular values of the parameters is derived.

Mathematical Modeling Of Nonlinear Blood Glucose-Insulin Dynamics With Beta Cells Effect, Gabriela Urbina, Daniel N. Riahi, Dambaru Bhatta

School of Mathematical & Statistical Sciences Faculty Publications

We consider mathematical modeling of blood glucose-insulin regulatory system with the additional effect of the secreted insulin by the pancreatic beta cells and in the presence of an external energy input to such system. Such modeling system is investigated to determine the time-dependent nonlinear dynamics that take place by the quantities, which represent the glucose and insulin concentrations in the blood, insulin action as well as in the absence or presence of secreted insulin due to the pancreatic beta cells. Using both analytical and numerical procedures, we determine such quantities versus time for both diabetes patients and normal human and …

An Effective Method To Obtain Contour Of Fisheye Images Based On Explicit Level Set Method, Xuegang Wu, Zhijun Qiao

School of Mathematical & Statistical Sciences Faculty Publications

Obtaining the effective contour from an image taken by fisheye lens is important for the following transactions. Many studies try to develop suitable methods to get accurate contours of fisheye images. Using the traditional level set method (CV model) is hard to meet the desire task that the final segmentation region is a circle. Therefore, the preprocessing of fisheye images and the improvement of traditional level set method are redesigned to get a final circular segmentation which may be suitable to other applications. In this paper, we use the local entropy method to make the value of pixels be even …

A New Species Of Chromis (Teleostei: Pomacentridae) From Mesophotic Coral Ecosystems Of Rapa Nui (Easter Island) And Salas Y Gomez, Chile, Bart Shepard, Hudson T. Pinheiro, Tyler A. Y. Phelps, Erin E. Easton, Alejandro Perez-Matus, Luiz A. Rocha

School of Earth, Environmental, & Marine Sciences Faculty Publications

A new species of Chromis (Teleostei: Pomacentridae) is described from three specimens collected at 90 m depth in a mesophotic coral ecosystem at Rapa Nui, Chile. Chromis mamatapara, new species, can be distinguished from its congeners by the following combination of characters: dorsal-fin rays XIV,13–14; pectoral-fin rays 18–19, third from top of fin longest; tubed lateral-line scales 18; total gill rakers on first arch 30–32; vertebrae 11þ15; and by coloration of living specimens, especially the presence of a single, pronounced, white spot, roughly the same diameter as the orbit, located where the posterior base of the dorsal fin intersects the …

The Pantropical Response Of Soil Moisture To El Niño, Kurt C. Solander, Brent D. Newman, Alessandro Carloca De Araujo, Holly R. Barnard, Z. Carter Berry, Damien Bonal, Mario Bretfeld, Benoit Burban, Luiz Antonio Candido, Rolando Celleri, Jeffery Q. Chambers, Bradley O. Christoffersen

School of Earth, Environmental, & Marine Sciences Faculty Publications

The 2015–2016 El Niño event ranks as one of the most severe on record in terms of the magnitude and extent of sea surface temperature (SST) anomalies generated in the tropical Pacific Ocean. Corresponding global impacts on the climate were expected to rival, or even surpass, those of the 1997–1998 severe El Niño event, which had SST anomalies that were similar in size. However, the 2015–2016 event failed to meet expectations for hydrologic change in many areas, including those expected to receive well above normal precipitation. To better understand how climate anomalies during an El Niño event impact soil moisture, …

Mechanical Properties And Microstructure Evolution Of Ti2alc Under Compression In 25–1100 °C Temperature Range, Rogelio Benitez, W. H. Kan, H. Gao, M. O'Neal, G. Proust, A. Srivastava, Miladin Radovic

Mechanical Engineering Faculty Publications

This study investigates the effects of the initial grain size and temperature (ranging from room temperature to 1100 °C) on the mechanical properties and microstructure evolution of Ti2AlC MAX phase. A Hall-Petch like relationship is observed between compressive strength and the grain size below brittle-to-plastic transition temperature (BPTT). However, the compressive strength of fine-grained MAX phase decreases more rapidly with increasing temperature resulting in inverse Hall-Petch effect above BPTT. Results from postmortem EBSD analysis reveal complex microstructural evolution in both fine- and coarse-grained microstructures during loading at different temperatures. The pronounced drop in compressive strength for fine-grained microstructures at temperatures …

Wildlife Use Of Road Mitigation Structures In Relation To Their Construction, Structural Characteristics, And Environmental Factors Along A South Texas Highway, Anna D. Rivera Roy

Theses and Dissertations

Roads are known to negatively impact wildlife by fragmenting habitat and mortality caused by wildlife-vehicle collisions. Road mitigation structures, such as wildlife crossing structures (WCS), wildlife guards (WG), and fencing are commonly used to address the issue of roads. In South Texas, such structures were built or modified along State Highway (SH) 100 in Cameron County as an effort to conserve the endangered ocelot (Leopardus pardalis). Camera traps were deployed to monitor these structures as a way to assess their effectiveness in restricting wildlife entry into the roadway with fencing and WG and conveying wildlife movement across roads …

The Underrepresentation Of African American Doctoral Students In College Of Education Disciplines At Hispanic Serving Institutions And Emerging Hispanic Serving Institutions In The Southwest United States (Texas, New Mexico, Arizona, California, Nevada And Colorado), Matthew Lloyd Atterberry

Theses and Dissertations

African Americans are underrepresented in higher education, especially in the graduate and doctoral level. Furthermore, research has identified numerous factors influencing African Americans to pursue doctoral studies in College of Education disciplines at postsecondary institutions of higher learning. However, there is a gap in the literature pertaining to factors influencing African Americans to pursue graduate and/or doctoral studies in College of Education disciplines at Hispanic Serving Institutions and Emerging Hispanic Institutions of higher learning in the Southwest United States. The purpose of this study is to bridge the gap pertaining to demographic factors in relationship to motivation and self-efficacy (Confidence) …

Mathematical Modeling Of Nonlinear Dynamics Of Blood Hormones On The Regulatory System, Gabriela Urbina

Theses and Dissertations

We study a mathematical modeling of nonlinear dynamics of blood hormones, which includes glucose and insulin. On Chapter I, II, III and IV, we introduce this work, analyze an effect of the secreted insulin by the pancreatic beta cells and glucagon hormones and state concluding remarks, respectively. This model considers the time evolution of nonlinear dynamics of the equations for glucose, glucagon and insulin concentrations plus insulin and glucagon actions and the secreted insulin as a result of elevation of glucose in the blood plasma. Using both analytical and numerical procedures, we determine such quantities using different parameters for different …

Assessing English Learners For Special Education Eligibility: Evaluator’S Perspectives And Procedures, Brenda Iveth De La Garza

Theses and Dissertations

There is a disproportionate number of English Learners (ELs) in Special Education across the United States (Kligner, Artiles, & Barletta, 2006). When educators are concerned about EL’s lack of progress and their underachievement they turn towards Special Education as a way of finding resources and a solution to their concerns (Kligner, Boile, Linan-Thompson & Rodriguez, 2014). This poses a challenge for evaluators, especially for those who lack or have little knowledge about the differences that exist between typical language acquisition differences and a learning disability. Evaluators who lack this knowledge might be more likely to confuse a student’s second language …

A Mathematical Approach To Gomoku, Oscar Garcia

Theses and Dissertations

This goal of this thesis is to design and implement a light weighted AI for playing Gomoku with high level intelligence. Our work is built upon an innovative algebraic monomial theory to help assess values for each possible move and estimate chances for the AI to win at each move. With the help of the monomial theory, we are able to convert winning configurations into monomials of variables that represent the underlying board positions. In the existing approaches to building an AI for playing Gomoku, one common challenge is about how to represent the present configuration of the game along …

Partial Differential Equations In Curved Spacetimes, Jorge A. Garcia

Theses and Dissertations

It is the ambition of this thesis to analyze in a concise and coherent manner the idiosyncratic nature of partial differential equations and their mathematical structure in distinct curved spacetimes. In our work special interest is taken in quantum fields dwelling within the de-Sitter geometry. In Chapters I, II, III, and IV, a meticulous study of general relativity is undertaken with one of its solutions derived, an introduction of quantum mechanics is posed, the relativistic quantum theory of fermions is defined, and a “merging” of the former chapters and results are considered, respectively. With what has been derived we seek …

Magnesium Diboride Embedded Multi-Walled Carbon Nanotube Yarns, Ujjal Lamichhane

Theses and Dissertations

The discovery of superconductivity in a simple hexagonal binary compound of MgB2 at a relatively high critical temperature ~39 K renewed the interest in the field of superconductivity. Twisted laminar superconducting composite structures based on coiled multi-walled carbon nanotube (MWCNT) yarns were crafted by integrating magnesium and boron homogeneous mixture into the carbon nanotube sheets. After the ignition of the Mg/B/MWCNT system, under the controlled argon environment and uniform heating rate, the high exothermic reaction between magnesium (Mg) and boron (B) with stoichiometric ratio produced the MgB2/MWCNT superconducting composite yarns. The XRD analysis confirmed that the heated sample consists of …

Algorithmic Assembly Of Nanoscale Structures, Austin Luchsinger

Theses and Dissertations

The development of nanotechnology has become one of the most significant endeavors of our time. A natural objective of this field is discovering how to engineer nanoscale structures. Limitations of current top-down techniques inspire investigation into bottom-up approaches to reach this objective. A fundamental precondition for a bottom-up approach is the ability to control the behavior of nanoscale particles. Many abstract representations have been developed to model systems of particles and to research methods for controlling their behavior. This thesis develops theories on two such approaches for building complex structures: the self-assembly of simple particles, and the use of simple …

Elucidating The Binding Pockect Of The Gpr119 Receptor, A Type 2 Diabetes Target, Matthew Dy Rosales

Theses and Dissertations

An in-house homology model of the GPR119 receptor was used to identify residues which may affect ligand binding and ligand-dependent activity through computational and experimental studies. In a docking study comparing an agonist and its inverse agonist structural analog, Leu5.43169, L6.52242 and Ser1.324 appear to be involved in ligand binding. These residues were mutated experimentally to test the predictions of the homology model. The in vitro studies indicate that Leu5.43169 and Ser1.324 mutations cause ten-fold and six-fold decreases in ligand-induced cAMP formation, indicating their importance in ligand-induced activation. Leu6.52242 mutations show minimal effect in cAMP production, indicating a lesser involvement …