47 research outputs found

    Constructing r-Uniform Hypergraphs with Restricted Clique Numbers

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    Ramsey theory has posed many interesting questions for graph theorists that have yet to be solved.  Many different methods have been used to find Ramsey numbers, though very few are actually known.  Because of this, more mathematical tools are needed to prove exact values of Ramsey numbers and their generalizations.  Budden, Hiller, Lambert, and Sanford have created a lifting from graphs to 3-uniform hypergraphs that has shown promise in extending known Ramsey results to hypergraphs.  This paper will consider another analogous lifting for rr-uniform hypergraphs and investigate the lifting of Turan graphs

    Optimization of the Penalty Parameter for the Dual-Wind Discontinuous Galerkin Methods on a Prototypical Second Order Pde.

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    A discontinuous Galerkin (DG) finite-element interior calculus is used as a common framework to describe various DG approximation methods for second- order elliptic problems. The dual-wind discontinuous Galerkin method (DWDG) has been shown to be stable and consistent for a wide range of penalty parameter values, including zero, for second order elliptic problems under certain mesh conditions. In this presentation, we will present the results of numerical experiments on various second order elliptic problems with varying penalty parameters that show the choice of zero for the penalty parameter is an optimal choice for application

    A lifting of graphs to 3-uniform hypergraphs, its generalization, and further investigation of hypergraph Ramsey numbers

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    Ramsey theory has posed many interesting questions for graph theorists that have yet to besolved. Many different methods have been used to find Ramsey numbers, though very feware actually known. Because of this, more mathematical tools are needed to prove exactvalues of Ramsey numbers and their generalizations. Budden, Hiller, Lambert, and Sanfordhave created a lifting from graphs to 3-uniform hypergraphs that has shown promise. Theybelieve that many results may come of this lifting, and have discovered some themselves.This thesis will build upon their work by considering other important properties of theirlifting and analogous liftings for higher-uniform hypergraphs. We also consider ways inwhich one may extend many known results in Ramsey Theory for graphs to the r-uniformhypergraph setting

    Double-lumen carotid plaque: A morbid configuration

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    AbstractDuring analysis of carotid plaque anatomy for a multicenter carotid imaging trial, we examined plaque specimens from 5 patients with double internal carotid artery lumina. Four of the 5 patients had symptoms referable to the lesion. The second lumen was noted when the plaque specimens were examined ex vivo with high-resolution (200 μm3) magnetic resonance imaging. Plaque structure was correctly identified in only 1 patient preoperatively. However, during retrospective review of the preoperative imaging studies, the second internal carotid artery lumen was identified in 3 patients

    Symmetric dual-wind discontinuous Galerkin methods for elliptic variational inequalities

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    The main goal of this dissertation is to formulate and analyze a dual wind discontinuous Galerkin method for approximating solutions to elliptic variational inequalities. A discontinuous Galerkin (DG) finite-element interior calculus is used as a common framework to describe various DG approximation methods for second-order elliptic problems. The dual-wind discontinuous Galerkin method is formulated for the obstacle problem with Dirichlet boundary conditions, ??_u _ f on with u = g on @, u _ on , and (_u ?? f)(u ?? ) = 0 on . A complete convergence analysis is developed and numerical experiments are recorded that verify these results. A secondary goal of this dissertation is to explore the effect of the penalty parameter on the error of the dual-wind discontinuous Galerkin method’s approximation to an elliptic partial differential equation. The dual-wind discontinuous Galerkin method is applied to the Poisson problem in two dimensions. The dual-wind discontinuous Galerkin approximation to the Poisson problem is constructed using various penalty parameters and the error is recorded for each approximation across various initial meshes and their refinements. [This abstract has been edited to remove characters that will not display in this system. Please see the PDF for the full abstract.]]]> 2020 Galerkin methods Discontinuous functions Variational inequalities (Mathematics) English http://libres.uncg.edu/ir/uncg/f/Rapp_uncg_0154D_13093.pdf oai:libres.uncg.edu/33277 2020-09-24T15:20:27Z UNCG Collectives and countercollectives: how the rhetoric of mass media persuades citizens in wartime NC DOCKS at The University of North Carolina at Greensboro Reed, Stacy <![CDATA[The purpose of the following analysis is to highlight rhetorical patterns common during wartime across multiple decades and forms of mass media communication, and to demonstrate how the technologies of media intersect with rhetorical patterns in the creation of collectives and countercollectives. By drawing on and extending the theories of Kenneth Burke and Marshall McLuhan, I pinpoint the similarities and differences in persuasive strategies across shifting electronic mass media, noting how rhetorical appeals remain consistent though the forms they take and the modes in which they are delivered by rhetors changes with historical context and technological affordances. Historical accounts and primary sources provide the basis for such rhetorical analysis. While the technology may change and become increasingly sophisticated in its affordances and accessibility, the rhetorical patterns of collectives and countercollectives remain similar, as strategic appeals to logos, pathos, and ethos are relied upon similarly by both pro- and antiwar collectives. The rhetorical analyses of the collectives and countercollectives across the four wars under investigation suggests useful strategies for rhetors of both present-day and future mass media communications

    The Hot QCD White Paper: Exploring the Phases of QCD at RHIC and the LHC

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    The past decade has seen huge advances in experimental measurements made in heavy ion collisions at the Relativistic Heavy Ion Collider (RHIC) and more recently at the Large Hadron Collider (LHC). These new data, in combination with theoretical advances from calculations made in a variety of frameworks, have led to a broad and deep knowledge of the properties of thermal QCD matter. Increasingly quantitative descriptions of the quark-gluon plasma (QGP) created in these collisions have established that the QGP is a strongly coupled liquid with the lowest value of specific viscosity ever measured. However, much remains to be learned about the precise nature of the initial state from which this liquid forms, how its properties vary across its phase diagram and how, at a microscopic level, the collective properties of this liquid emerge from the interactions among the individual quarks and gluons that must be visible if the liquid is probed with sufficiently high resolution. This white paper, prepared by the Hot QCD Writing Group as part of the U.S. Long Range Plan for Nuclear Physics, reviews the recent progress in the field of hot QCD and outlines the scientific opportunities in the next decade for resolving the outstanding issues in the field.Comment: 110 pages, 33 figures, 429 references. Prepared as part of the U.S. Long-Range Plan for Nuclear Physic

    Pediatric Acupuncture: A Review of Clinical Research

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    Practiced in China for more than 2000 years, acupuncture has recently gained increased attention in the United States as an alternative treatment approach for a variety of medical conditions. Despite its growing prevalence and anecdotal reports of success among pediatric populations, few empirically based studies have assessed the efficacy of acupuncture for children and adolescents. This article presents a review of the current literature, including a systematic appraisal of the methodological value of each study and a discussion of potential benefits and adverse effects of acupuncture. While acupuncture holds great promise as a treatment modality for diverse pediatric conditions, a significant amount of additional research is necessary to establish an empirical basis for the incorporation of acupuncture into standard care

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    The genetic architecture of the human cerebral cortex

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    The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure
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