Physical Sciences and Mathematics Commons^™

Bounds For The Zero Forcing Number Of Graphs With Large Girth, Randy Davila, Franklin Kenter

Theory and Applications of Graphs

The zero-forcing number, Ζ(G) is an upper bound for the maximum nullity of all symmetric matrices with a sparsity pattern described by the graph. A simple lower bound is δ ≤ Ζ(G) where δ is the minimum degree. An improvement of this bound is provided in the case that G has girth of at least 5. In particular, it is shown that 2δ − 2 ≤ Ζ(G) for graphs with girth of at least 5; this can be further improved when G has a small cut set. Lastly, a conjecture is made regarding a lower bound for Ζ(G) as a …

Phyro: Exploring An Untethered Model For Robots In Cs-1, Philip Franchi-Pereira

Senior Projects Fall 2015

Robots are becoming more popular, both industrially and commercially. As new robots are created, designers must choose whether to tether to a primary computer. Many robots used in an introductory computing context, like the Scribbler robot and Fluke attachment, are tethered. Untethering educational robots is the next step in improving the way robots are used in CS-1. This project aims to demonstrate the advantages of untethered robots, using the Scribbler robot and Fluke singleboard computer attachment as a model. We developed the Phyro library to make programming an untethered Scribbler and Fluke easier for students. By comparing program performance and …

The Relationship Between Particle Travel Distance And Channel Morphology: Results Fromphysicalmodels Of Braided Rivers, Alan Kasprak, Joseph Wheaton, Peter Ashmore, James Hensleigh, Sarah Peirce

Geography & Environment Publications

Channel form and sediment transport are closely linked in alluvial rivers, and as such the development of a conceptual framework for the downstream controls on particle mobility and likely deposition sites has immense value in terms of the way we understand and predictively model rivers. Despite the development of conceptual models which frame flood-scale particle transport distance (termed path length) as a function of channel bar locations, an understanding of the controls on such path lengths in braided rivers remains especially elusive, in large part due to the difficulty in explicitly linking morphology and particle transport distances in the field. …

Twentieth Century Droughts And Agriculture: Examples From Impacts On Soybean Production In Kentucky, Usa, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Chebyshev Polynomials And The Frohman-Gelca Formula, Heather M. Russell, Hoel Queffelec

Department of Math & Statistics Faculty Publications

Using Chebyshev polynomials, C. Frohman and R. Gelca introduced a basis of the Kauffman bracket skein module of the torus. This basis is especially useful because the Jones–Kauffman product can be described via a very simple Product-to-Sum formula. Presented in this work is a diagrammatic proof of this formula, which emphasizes and demystifies the role played by Chebyshev polynomials.

The Robinson-Schensted Correspondence And A2-Web Bases, Heather M. Russell, Matthew Housley, Julianna Tymoczko

Department of Math & Statistics Faculty Publications

We study natural bases for two constructions of the irreducible representation of the symmetric group corresponding to [n; n; n]: the reduced web basis associated to Kuperberg's combinatorial description of the spider category; and the left cell basis for the left cell construction of Kazhdan and Lusztig. In the case of [n; n], the spider category is the Temperley-Lieb category; reduced webs correspond to planar matchings, which are equivalent to left cell bases. This paper compares the image of these bases under classical maps: the Robinson-Schensted algorithm between permutations and Young tableaux and Khovanov-Kuperberg's bijection between …

Holocene Sedimentology And Stratigraphy Of Coastal Sediments In An Arid Climate, Al Qahmah, Southern Red Sea, Saudi Arabia, Abdullah Ibrahim Nabhan

Doctoral Dissertations

"Holocene sedimentary deposits in Al Qahmah coast, southern Red Sea, in Saudi Arabia have been accumulated on an arid siliciclastic coast in a rift tectonic setting. This study provides a detail interpretation and analysis of sedimentary facies, stratigraphy, depositional environment, and major geological processes. Two studies have been undertaken. First, petrological study of composition and texture of modern sediments and facies mapping delineate facies distribution and mechanisms of sediment transport and deposition. A unique suite of complex riverine, wave, tidal, wind, and chemical and biological processes affect the composition, texture, and distribution of the facies. Second, the depositional environments of …

Quantum Tests Of The Einstein Equivalence Principle With The Ste–Quest Space Mission, Brett David Altschul, Quentin G. Bailey, Luc Blanchet, Kai Bongs, Philippe Bouyer, Luigi Cacciapuoti, Salvatore Capozziello, Naceur Gaaloul, Domenico Giulini, Jonas Hartwig, Luciano Iess, Philippe Jetzer, Arnaud Landragin, Ernst Rasel, Serge Reynaud, Stephan Schiller, Christian Schubert, Fiodor Sorrentino, Uwe Sterr, Jay D. Tasson, Guglielmo M. Tino, Philip Tuckey, Peter Wolf

Faculty Publications

We present in detail the scientific objectives in fundamental physics of the Space–Time Explorer and QUantum Equivalence Space Test (STE–QUEST) space mission. STE–QUEST was pre-selected by the European Space Agency together with four other missions for the cosmic vision M3 launch opportunity planned around 2024. It carries out tests of different aspects of the Einstein Equivalence Principle using atomic clocks, matter wave interferometry and long distance time/frequency links, providing fascinating science at the interface between quantum mechanics and gravitation that cannot be achieved, at that level of precision, in ground experiments. We especially emphasize the specific strong interest of performing …

Remote Sensing And Modeling Of Atmospheric Dust And Studying Its Impact On Environment, Weather, And Climate, Hesham El-Askary, Seon K. Park, Slobodan Nickovic, Mian Chin

Mathematics, Physics, and Computer Science Faculty Articles and Research

An overview of the 2015 volume of Advances in Meteorology, which was co-edited by Chapman faculty member Dr. Hesham El-Askary.

Binary Star Systems With Asymmetrically Heated Disks: Thermal Phase Curves For The Disk In Epsilon Aurigae, Richard Luther Pearson Iii

Electronic Theses and Dissertations

Epsilon Aurigae is a long-period eclipsing binary that contains a warm F-star (~7750 K) and a circumstellar disk enshrouding a hidden companion, likely to be a hot B-star (>15,000 K). The eclipse itself lasts just over two years---thanks, in part, to the size of the disk---and occurs every 27.1-years. Its evolutionary status is still debated, along with the true nature of each stellar component, due to the high uncertainty in its parallax. The disk is similarly debated from the near absence of solid state infrared spectral features indicating its composition, particle size distribution, and density. An investigation of a …

Monolithic Optofluidic Ring Resonator Lasers Created By Femtosecond Laser Nanofabrication, Hengky Chandrahalim, Qiushu Chen, Ali A. Said, Mark Dugan, Xudong Fan

Faculty Publications

We designed, fabricated, and characterized a monolithically integrated optofluidic ring resonator laser that is mechanically, thermally, and chemically robust. The entire device, including the ring resonator channel and sample delivery microfluidics, was created in a block of fused-silica glass using a 3-dimensional femtosecond laser writing process. The gain medium, composed of Rhodamine 6G (R6G) dissolved in quinoline, was flowed through the ring resonator. Lasing was achieved at a pump threshold of approximately 15 μJ/mm². Detailed analysis shows that the Q-factor of the optofluidic ring resonator is 3.3 × 10⁴, which is limited by both solvent …

Using Higher Ionization States To Increase Coulomb Coupling In An Ultracold Neutral Plasma, M. Lyon, Scott D. Bergeson, A. Diaw, M. S. Murillo

Faculty Publications

We report measurements and simulations of the time-evolving rms velocity distribution in an ultracold neutral plasma. A strongly coupled ultracold neutral Ca⁺ plasma is generated by photoionizing laser-cooled atoms close to threshold. A fraction of these ions is then promoted to the second ionization state to form a mixed Ca⁺-Ca²⁺ plasma. By varying the time delay between the first and the second ionization events, a minimum in ion heating is achieved. We show that the Coulomb strong-coupling parameter Γ increases by a factor of 1.4 to a maximum value of 3.6. A pure Ca²⁺ plasma …

Instrument For Precision Long-Term Ss-Decay Rate Measurements, M. J. Ware, Scott D. Bergeson, J. E. Ellsworth, M. Groesbeck, J. E. Hansen, D. Pace, J. Peatross

Faculty Publications

We describe an experimental setup for making precision measurements of relative ß-decay rates of ²²Na, ³⁶Cl, ⁵⁴Mn, ⁶⁰Co, ⁹⁰Sr, ¹³³Ba, ¹³⁷Cs, ¹⁵²Eu, and ¹⁵⁴Eu. The radioactive samples are mounted in two automated sample changers that sequentially position the samples with high spatial precision in front of sets of detectors. The set of detectors for one sample changer consists of four Geiger-Müller (GM) tubes and the other set of detectors consists of two NaI scintillators. The statistical uncertainty in the count rate is few times 0.01% per day for the GM …

Strongly-Coupled Plasmas Formed From Laser-Heated Solids, M. Lyon, Scott D. Bergeson, G. Hart, M. S. Murillo

Faculty Publications

We present an analysis of ion temperatures in laser-produced plasmas formed from solids with different initial lattice structures. We show that the equilibrium ion temperature is limited by a mismatch between the initial crystallographic configuration and the close-packed configuration of a strongly-coupled plasma, similar to experiments in ultracold neutral plasmas. We propose experiments to demonstrate and exploit this crystallographic heating in order to produce a strongly coupled plasma with a coupling parameter of several hundred.

Building A Scalable Global Data Processing Pipeline For Large Astronomical Photometric Datasets, Paul F. Doyle

Doctoral

Astronomical photometry is the science of measuring the flux of a celestial object. Since its introduction in the 1970s the CCD has been the principle method of measuring flux to calculate the apparent magnitude of an object. Each CCD image taken must go through a process of cleaning and calibration prior to its use. As the number of research telescopes increases the overall computing resources required for image processing also increases. As data archives increase in size to Petabytes, the data processing challenge requires image processing approaches to evolve to continue to exceed the growing data capture rate. Existing processing …

Context-Based Access For Infrequent Requests In Tanzania's Health Care System, Zanifa Omary

Doctoral

Access control is an important aspect of any information system. It is a way of ensuring that users can only access what they are authorised to and no more. This can be achieved by granting users access to resources based on pre-defined organisational and legislative rules. Although access control has been extensively studied, and as a result, a wide range of access control models, mechanisms and systems have been proposed, specific access control requirements for healthcare systems that needs to support the continuity of care in an accountable manner have not been addressed. This results in a gap between what …

Refraction In Mozambique: Evaluations Of Practice And Development Of Competency Frameworks For Eye Care Personnel, Kajal Shah

Doctoral

Purpose The development of competency- based education for optometrists and mid-level eye-care personnel has been identified as an important component in the elimination of avoidable blindness and vision impairment. The Mozambique Eye care Project (MEP) is a multi-institutional collaboration, which seeks to facilitate greater access to training in eye health professions, which will ultimately contribute to providing affordable and accessible eye care within the public health system in Mozambique. An important tenet of the MEP is to develop and enhance the refraction training of all existing (ophthalmic technicians) and new eye care personnel (four-year training of optometrists and eighteen-month training …

Learning Emotions: A Software Engine For Simulating Realistic Emotion In Artificial Agents, Douglas Code

Senior Independent Study Theses

This paper outlines a software framework for the simulation of dynamic emotions in simulated agents. This framework acts as a domain-independent, black-box solution for giving actors in games or simulations realistic emotional reactions to events. The emotion management engine provided by the framework uses a modified Fuzzy Logic Adaptive Model of Emotions (FLAME) model, which lets it manage both appraisal of events in relation to an individual’s emotional state, and learning mechanisms through which an individual’s emotional responses to a particular event or object can change over time. In addition to the FLAME model, the engine draws on the design …

Gis Data: Prince William County, Virginia Shoreline Management Model, Marcia Berman, Harry Berquist, Sharon Killeen, Carl Hershner, Karinna Nunez, Karen Reay, Tamia Rudnicky

Data

No abstract provided.

Drive-Based Utility-Maximizing Computer Game Non-Player Characters, Colm Sloan

Doctoral

This research examines the emergence of the five-string fiddle in contemporary North American fiddle culture within the past ten years. By interacting with leading artistlevel practitioners, the research documents the evolution and impact of the instrument to date in exploring the possibilities the five-string fiddle presents for musical performance and innovation. North American vernacular music and, in particular, the contemporary fiddle playing landscape, exemplifies virtousic and innovative idiomatic technique and improvisation as central to an overarching musical explosion, evidenced in the music of many high level, multi-stylistic contemporary practitioners. Within contemporary American fiddle performance, it is compelling to observe how …

A Comparison Of Cloud Computing Database Security Algorithms, Joseph A. Hoeppner

UNF Graduate Theses and Dissertations

The cloud database is a relatively new type of distributed database that allows companies and individuals to purchase computing time and memory from a vendor. This allows a user to only pay for the resources they use, which saves them both time and money. While the cloud in general can solve problems that have previously been too costly or time-intensive, it also opens the door to new security problems because of its distributed nature. Several approaches have been proposed to increase the security of cloud databases, though each seems to fall short in one area or another.

This thesis presents …

Choice Of Human–Computer Interaction Mode In Stroke Rehabilitation, Hossein Mousavi Hondori, Maryam Khademi, Lucy Dodakian, Alison Mackenzie, Cristina V. Lopes, Steven C. Cramer

Physical Therapy Faculty Articles and Research

Background and Objective. Advances in technology are providing new forms of human–computer interaction. The current study examined one form of human–computer interaction, augmented reality (AR), whereby subjects train in the real-world workspace with virtual objects projected by the computer. Motor performances were compared with those obtained while subjects used a traditional human–computer interaction, that is, a personal computer (PC) with a mouse. Methods. Patients used goal-directed arm movements to play AR and PC versions of the Fruit Ninja video game. The 2 versions required the same arm movements to control the game but had different cognitive demands. With …

Query From Examples: An Iterative, Data-Driven Approach To Query Construction, Hao Li, Chee-Yong Chan, David Maier

Computer Science Faculty Publications and Presentations

In this paper, we propose a new approach, called Query from Examples (QFE), to help non-expert database users construct SQL queries. Our approach, which is designed for users who might be unfamiliar with SQL, only requires that the user is able to determine whether a given output table is the result of his or her intended query on a given input database. To kick-start the construction of a target query Q, the user first provides a pair of inputs: a sample database D and an output table R which is the result of Q on D. As there will be …

Salt And Water Uptake In Nanocon!Nement Under Applied Electric Field: An Open Ensemble Monte Carlo Study, F. Moucka, D. Bratko, A. Luzar

Chemistry Publications

Permeation of electrolytes in nanoporous materials underlies many applications in energy and materials technologies. Wetting of apolar nanopores can be enhanced by electric !eld, attracting water and ions from unperturbed electrolyte bath. We study absorption of water and NaCl in the pores by Expanded Ensemble Grand Canonical Monte Carlo simulation, which implements particle insertions and deletions through incremental changes in particles’ coupling with the system. We determine the uptake of water and ions in the pores, and concomitant changes in pore thermodynamics, as functions of !eld strength in the pore and salinity in the external bath. Pressure increase and reduction …

Identification Of Point Defects In Hvpe-Grown Gan By Steady-State And Time-Resolved Photoluminescence, Michael A. Reshchikov, Denis O. Demchenko, A Usikov, H Helava, Yu. Makarov

Forensic Science Publications

We have investigated point defects in GaN grown by HVPE by using steady-state and time-resolved photoluminescence (PL). Among the most common PL bands in this material are the red luminescence band with a maximum at 1.8 eV and a zero-phonon line (ZPL) at 2.36 eV (attributed to an unknown acceptor having an energy level 1.130 eV above the valence band), the blue luminescence band with a maximum at 2.9 eV (attributed to ZnGa), and the ultraviolet luminescence band with the main peak at 3.27 eV (related to an unknown shallow acceptor). In GaN with the highest quality, the dominant defect-related …

A New Silicon Phase With Direct Band Gap And Novel Optoelectronic Properties, Yaguang Guo, Qian Wang, Yoshiyuki Kawazoe, Puru Jena

Physics Publications

Due to the compatibility with the well-developed Si-based semiconductor industry, there is considerable interest in developing silicon structures with direct energy band gaps for effective sunlight harvesting. In this paper, using silicon triangles as the building block, we propose a new silicon allotrope with a direct band gap of 0.61 eV, which is dynamically, thermally and mechanically stable. Symmetry group analysis further suggests that dipole transition at the direct band gap is allowed. In addition, this new allotrope displays large carrier mobility (~104 cm/V · s) at room temperature and a low mass density (1.71 g/cm3), making …

The Support Vector Machine And Mixed Integer Linear Programming: Ramp Loss Svm With L1-Norm Regularization, Eric J. Hess, J. Paul Brooks

Statistical Sciences and Operations Research Publications

The support vector machine (SVM) is a flexible classification method that accommodates a kernel trick to learn nonlinear decision rules. The traditional formulation as an optimization problem is a quadratic program. In efforts to reduce computational complexity, some have proposed using an L1-norm regularization to create a linear program (LP). In other efforts aimed at increasing the robustness to outliers, investigators have proposed using the ramp loss which results in what may be expressed as a quadratic integer programming problem (QIP). In this paper, we consider combining these ideas for ramp loss SVM with L1-norm regularization. The result is four …

Firing Rate Dynamics In Recurrent Spiking Neural Networks With Intrinsic And Network Heterogeneity, Cheng Ly

Statistical Sciences and Operations Research Publications

Heterogeneity of neural attributes has recently gained a lot of attention and is increasing recognized as a crucial feature in neural processing. Despite its importance, this physiological feature has traditionally been neglected in theoretical studies of cortical neural networks. Thus, there is still a lot unknown about the consequences of cellular and circuit heterogeneity in spiking neural networks. In particular, combining network or synaptic heterogeneity and intrinsic heterogeneity has yet to be considered systematically despite the fact that both are known to exist and likely have significant roles in neural network dynamics. In a canonical recurrent spiking neural network model, …

Building A Scalable Global Data Processing Pipeline For Large Astronomical Photometric Datasets, Paul Doyle

Other

Astronomical photometry is the science of measuring the flux of a celestial object. Since its introduction, the CCD has been the principle method of measuring flux to calculate the apparent magnitude of an object. Each CCD image taken must go through a process of cleaning and calibration prior to its use. As the number of research telescopes increases the overall computing resources required for image processing also increases. Existing processing techniques are primarily sequential in nature, requiring increasingly powerful servers, faster disks and faster networks to process data. Existing High Performance Computing solutions involving high capacity data centres are complex …

Presenting Distributive Laws, Marcello M. Bonsangue, Helle H. Hansen, Alexander Kurz, Jurriaan Rot

Engineering Faculty Articles and Research

Distributive laws of a monad T over a functor F are categorical tools for specifying algebra-coalgebra interaction. They proved to be important for solving systems of corecursive equations, for the specification of well-behaved structural operational semantics and, more recently, also for enhancements of the bisimulation proof method. If T is a free monad, then such distributive laws correspond to simple natural transformations. However, when T is not free it can be rather difficult to prove the defining axioms of a distributive law. In this paper we describe how to obtain a distributive law for a monad with an equational presentation …