Physical Sciences and Mathematics Commons^™

Principal Angles And Approximation For Quaternionic Projections [Dataset], Terry A. Loring

Math and Statistics Datasets

We extend Jordan's notion of principal angles to work for two subspaces of quaternionic space, and so have a method to analyze two orthogonal projections in the matrices over the real, complex or quaternionic field (or skew field). From this we derive an algorithm to turn almost commuting projections into commuting projections that minimizes the sum of the displacements of the two projections. We quickly prove what we need using the universal real C*-algebra generated by two projections.

Estimating Norms Of Commutators [Dataset], Terry A. Loring, Freddy Vides

Math and Statistics Datasets

We find estimates on the norm of a commutator of the form [f(x),y] in terms of the norm of [x,y], assuming that x and y are bounded linear operators on Hilbert space, with x normal and with spectrum within the domain of f. In particular we discuss |[x^2,y]| and |[x^{1/2},y]| for 0leq x leq 1. For larger values of delta = |[x,y]| we can rigorous calculate the best possible upper bound |[f(x),y]| leq eta_f(delta) for many f. In other cases we have conducted numerical experiments that strongly suggest that we have in many cases found the correct formula for the …

Computing A Logarithm Of A Unitary Matrix With General Spectrum [Dataset], Terry A. Loring

Math and Statistics Datasets

We analyze an algorithm for computing a skew-Hermitian logarithm of a unitary matrix, and also skew-Hermitian approximate logarithms for nearly unitary matrices. This algorithm is very easy to implement using standard software and it works well even for unitary matrices with no spectral conditions assumed. Certain examples, with many eigenvalues near -1, lead to very non-Hermitian output for other basic methods of calculating matrix logarithms. Altering the output of these algorithms to force an Hermitian output creates accuracy issues which are avoided by the considered algorithm. A modification is introduced to deal properly with the J-skew symmetric unitary matrices. Applications …

Leslie Matrices For Logistic Population Modeling, Bruce Kessler

Mathematics Faculty Publications

Leslie matrices are taught as a method of modeling populations in a discrete-time fashion with more detail in the tracking of age groups within the population. Leslie matrices have limited use in the actual modeling of populations, since when the age groups are summed, it is basically equivalent to discrete-time modeling assuming exponential population growth. The logistic model of population growth is more realistic, since it takes into account a carrying capacity for the environment of the population. This talk will describe an adjustment to the Leslie matrix approach for population modeling that is both takes into account the carrying …

Controls On Particle Settling Velocity And Bed Erodibility In The Presence Of Muddy Flocs And Biologically Packaged Pellets: Modeling Study Utilizing The York 3-D Hydrodynamic Cohesive Bed Model, K. A. Fall, Courtney K. Harris, Carl T. Friedrichs, J. P. Rinehimer

Presentations

No abstract provided.

Controls On Particle Settling Velocity And Bed Erodibility In The Presence Of Muddy Flocs And Pellets As Inferred By Advs, York River Estuary, Virginia, Usa, K. A. Fall, C. T. Friedrichs, G. M. Cartwright

Presentations

.

Sediment Settling Velocity From Advs And Settling Tubes: Agreement Over A Range Of Particle Types And Hydrodynamic Conditions, G. M. Cartwright, C. T. Friedrichs, S. J. Smith

Presentations

No abstract provided.

0112+1703_Nir_Gnirs, Michael C. Liu

Publications and Research

No abstract provided.

2114-2251_Nir_Gnirs, Michael C. Liu

Publications and Research

No abstract provided.

Recent Field Observations Of Mixed And Cohesive Sediment Particle Properties In Coastal And Estuarine Environments, C. T. Friedrichs

Presentations

No abstract provided.

Comparison Of Sontek Advocean-Hydras And Nortek Adv Vectors For Measuring Suspended Sediment Concentration Via Acoustic Backscatter, G. M. Cartwright, C. T. Friedrichs, R. Pico Vila, P. D. Panetta

Presentations

No abstract provided.

2012 Chesapeake Bay Sav Coverage, Sav Data Administrator, Virginia Institute Of Marine Science

Data

Abstract: The 2012 Chesapeake Bay SAV Coverage was mapped from 1:24,000 black and white aerial photography to assess water quality in the Bay. Each area of SAV was interpreted from the rectified photography and classified into one of four density classes by the percentage of cover. The SAV beds were entered into an SDE GIS fetaure class using the quality control procedures documented below. The dataset contains all SAV areas that were identified from the areas flown. Some areas that are presumed to contain no SAV were not flown. Some small beds, particularly along narrow tributaries may not have been …

Combining Observations And Numerical Model Results To Improve Estimates Of Hypoxic Volume Within The Chesapeake Bay, A. Bever, M. Friedrichs, C. Friedrichs, M. Scully

Presentations

No abstract provided.

Collaborative Opportunities With The Physical Sciences Research Group, C. T. Friedrichs

Presentations

No abstract provided.

Rainich-Type Conditions For Null Electrovacuum Spacetimes Ii, Charles G. Torre

Research Vignettes

In this second of two worksheets I continue describing local Rainich-type conditions which are necessary and sufficient for the metric to define a null electrovacuum. In other words, these conditions, which I will call the null electrovacuum conditions, guarantee the existence of a null electromagnetic field such that the metric and electromagnetic field satisfy the Einstein-Maxwell equations. When it exists, the electromagnetic field is easily constructed from the metric. In this worksheet I consider the null electrovacuum conditions which apply when a certain null geodesic congruence determined by the metric is twisting. I shall illustrate the these conditions using a …

Phanerozoic Surface History Of The Slavecraton, Alexis K. Ault, Rebecca M. Flowers, Samuel A. Bowring

Geosciences Faculty Publications

New apatite (U-Th)/He (AHe) thermochronometry data and key geologic constraints from Slave craton kimberlites are used to develop a model for the Phanerozoic burial, unroofing, and hypsometric history of the northwestern Canadian shield. AHe dates range from 210 ± 13 to 382 ± 79 Ma, are older in the eastern Slave craton and decrease westward, and resolve the spatial extent, thickness, and history of now-denuded sedimentary units. Results indicate Paleozoic heating to temperatures ≥85–90°C, suggesting regional burial beneath ≥2.8 km of strata while the region was at sea level, followed by the westward migration of unroofing across the craton. This …

Empirical Investigation Of The Factors Influencing Marine Applications Of Emi, V. A. Bell, T. D. Steinhurst, C. Friedrichs

Presentations

No abstract provided.

Peaklet Analysis: Software For Spectrum Analysis, Bruce Kessler

Mathematics Faculty Publications

This is the presentation I was invited to give at the Kentucky Innovation and Entrepreneurship Conference, regarding the software that I have developed and worked at commercializing with the help of Kentucky Science and Technology Corporation.

Gr 20 Workshop, Warsaw, July 2013, Ian M. Anderson, Charles G. Torre

Presentations

These are the Maple worksheets used at the Differential Geometry in Maple Workshop, which was held at the 20th International Conference on General Relativity and Gravitation, in Warsaw, July 2013.

There are 6 worksheets which can be downloaded from the list of files below.

Using Tabu Search To Configure Support Vector Regression For Effort Estimation, A. Corazza, S. Di Martino, F. Ferrucci, C. Gravino, F. Sarro, E. Mendes

All Works

Recent studies have reported that Support Vector Regression (SVR) has the potential as a technique for software development effort estimation. However, its prediction accuracy is heavily influenced by the setting of parameters that needs to be done when employing it. No general guidelines are available to select these parameters, whose choice also depends on the characteristics of the dataset being used. This motivated the work described in (Corazza et al. 2010), extended herein. In order to automatically select suitable SVR parameters we proposed an approach based on the use of the meta-heuristics Tabu Search (TS). We designed TS to search …

Infrared Spectroscopy Of Symbiotic Stars. Ix. D-Type Symbiotic Novae, Kenneth H. Hinkle, Francis C. Fekel, Richard R. Joyce, Peter R. Wood

Information Systems and Engineering Management Research Publications

Time-series spectra of the near-infrared 1.6 μm region have been obtained for five of the six known D-type symbiotic novae. The spectra map the pulsation kinematics of the Mira component in the Mira–white dwarf binary system and provide the center-of-mass velocity for the Mira. No orbital motion is detected in agreement with previous estimates of orbital periods ≳100 yr and semimajor axes ∼50 AU. The 1–5 μm spectra of the Miras show line weakening during dust obscuration events. This results from scattering and continuum emission by 1000 K dust. In the heavily obscured HM Sge system the 4.6 μm CO …

Rainich-Type Conditions For Null Electrovacuum Spacetimes I, Charles G. Torre

Research Vignettes

In this worksheet I describe local Rainich-type conditions on a spacetime geometry which are necessary and sufficient for the existence of a solution of the Einstein-Maxwell equations with a null electromagnetic field. When it exists, the electromagnetic field is easily constructed.

How To Find Killing Vectors, Charles G. Torre

How to... in 10 minutes or less

We show how to compute the Lie algebra of Killing vector fields of a metric in Maple using the commands KillingVectors and LieAlgebraData. A Maple worksheet and a PDF version can be found below.

How To Find A Levi Decomposition Of A Lie Algebra, Ian M. Anderson

How to... in 10 minutes or less

We show how to compute the Levi decomposition of a Lie algebra in Maple using the command LeviDecomposition. A worksheet and corresponding PDF can be found below.

Development, Testing, And Deployment Of An Air Sampling Manifold For Spiking Elemental And Oxidized Mercury During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), B. D. Finley, D. A. Jaffe, K. Call, Seth Lyman, M. Sexauer Gustin, C. Peterson, M. Miller, T. Lyman

USU Uintah Basin Faculty Publications

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was in Reno, NV from August 22, 2011 to September 16, 2011. The goals of the experiment were to compare existing and new methods for measurements of ambient elemental and oxidized Hg, and to test these with quantitative spikes of Hg0, HgBr2, O3 and water vapor. In this paper we describe the design, testing, and deployment of a high flow manifold system designed to deliver ambient air and spiked compounds to multiple instruments simultaneously. The manifold was constructed of 1” OD PFA tubing and heated to 115 °C for the entire active zone. …

How To Create A Jordan Algebra, Ian M. Anderson, Thomas J. Apedaile

How to... in 10 minutes or less

We show how to create a Jordan algebra in Maple using the commands AlgebraLibraryData and AlgebraData.

How To Create The Quaternion & Octonion Algebras, Ian M. Anderson, Thomas J. Apedaile

How to... in 10 minutes or less

We show how to create the quaternion and octonion algebras with the DifferentialGeometry software. For each algebra, there is a split-form also available.

Fast Time Resolution Oxidized Mercury Measurements During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), Jesse L. Ambrose, Seth N. Lyman, Jiaoyan Huang, Mae Sexauer Gustin, Daneil A. Jaffe

USU Uintah Basin Faculty Publications

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was carried out from 22 August to 16 September, 2011 in Reno, NV to evaluate the performance of new and existing methods to measure atmospheric mercury (Hg). Measurements were made using a common sampling manifold to which controlled concentrations of Hg species, including gaseous elemental mercury (GEM) and HgBr2 (a surrogate gaseous oxidized mercury (GOM) compound), and potential interferents were added. We present an analysis of Hg measurements made using the University of Washington’s Detector for Oxidized Hg Species (DOHGS), focusing on tests of GEM and HgBr2 spike recovery, the potential for interference …

Do We Understand What The Mercury Speciation Instruments Are Actually Measuring? Results Of Ramix, Mae Sexauer Gustin, Jiaoyan Huang, Matthieu B. Miller, Christianna Peterson, Daniel A. Jaffe, Jesse Ambrose, Brandon D. Finley, Seth N. Lyman, Kevin Call, Robert Talbotl, Dara Feddersen, Huiting Mao, Steven E. Lindberg

USU Uintah Basin Faculty Publications

From August 22 to September 16, 2012, atmospheric mercury (Hg) was measured from a common manifold in the field during the Reno Atmospheric Mercury Intercomparison eXperiment. Data were collected using Tekran systems, laser induced fluorescence, and evolving new methods. The latter included the University of Washington-Detector for Oxidized Mercury, the University of Houston Mercury instrument, and a filter-based system under development by the University of Nevada-Reno. Good transmission of total Hg was found for the manifold. However, despite application of standard protocols and rigorous quality control, systematic differences in operationally defined forms of Hg were measured by the sampling systems. …

Adding Gas Chromatography-Mass Spectrometry Data To A Melting Point And Thin-Layer Chromatography Laboratory, Adam M. Azman, Julie A. Barrett, Megan Darragh, John J. Esteb

Scholarship and Professional Work - LAS

The addition of gas chromatography–mass spectrometry (GC–MS) data interpretation to a thin-layer chromatography (TLC) and melting point (mp) laboratory for an introductory organic course is described.