Digital Commons Network^™

A Characterization Of Box-Mengerian Matroid Ports, Xujin Chen, Guoli Ding, Wenan Zang

Faculty Publications

Let M be a matroid on E ∪ {l}, where l ∉ E is a distinguished element of M. The l-port of M is the set P = {P: P ⊆ E with P ∪ {l} a circuit of M }. Let A be the P-E incidence matrix. Let U2,4 be the uniform matroid on four elements of rank two, let F7 be the Fano matroid, let F*7 be the dual of F7, and let F 7+ be the unique series extension of F7. In this paper, we prove that the system Ax ≥ 1, x ≥ 0 is box-totally …

A Local Paley-Wiener Theorem For Compact Symmetric Spaces, Gestur Ólafsson, Henrik Schlichtkrull

Faculty Publications

The Fourier coefficients of a smooth K-invariant function on a compact symmetric space M = U / K are given by integration of the function against the spherical functions. For functions with support in a neighborhood of the origin, we describe the size of the support by means of the exponential type of a holomorphic extension of the Fourier coefficients. © 2007 Elsevier Inc. All rights reserved.

A Chain Theorem For Matroids, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

Tutte's Wheels-and-Whirls Theorem proves that if M is a 3-connected matroid other than a wheel or a whirl, then M has a 3-connected minor N such that | E (M) | - | E (N) | = 1. Geelen and Whittle extended this theorem by showing that when M is sequentially 4-connected, the minor N can also be guaranteed to be sequentially 4-connected, that is, for every 3-separation (X, Y) of N, the set E (N) can be obtained from X or Y by successively applying the operations of closure and coclosure. Hall proved a chain theorem for a different …

Diffractive Photoproduction Of Dijets In Ep Collisions At Hera, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, G. Sartorelli, A. Zichichi

Faculty Publications

Diffractive photoproduction of dijets was measured with the ZEUS detector at the ep collider HERA using an integrated luminosity of 77.2 pb-1. The measurements were made in the kinematic range Q2 < 1 GeV 2, 0.20

Making The Implicit Explicit: Creating Performance Expectations For The Dissertation, Debra S. Gentry

Faculty Publications

No abstract provided.

Optical Phase Unwrapping In The Presence Of Branch Points, Todd M. Venema, Jason D. Schmidt

Faculty Publications

Strong turbulence causes phase discontinuities known as branch points in an optical field. These discontinuities complicate the phase unwrapping necessary to apply phase corrections onto a deformable mirror in an adaptive optics (AO) system. This paper proposes a non-optimal but effective and implementable phase unwrapping method for optical fields containing branch points. This method first applies a least-squares (LS) unwrapper to the field which isolates and unwraps the LS component of the field. Four modulo-2π-equivalent non-LS components are created by subtracting the LS component from the original field and then restricting the result to differing ranges. 2π phase jumps known …

Integrating Trust Into The Cybercraft Initiative Via The Trust Vectors Model, Michael Stevens, Paul D. Williams, Gilbert L. Peterson, Stuart H. Kurkowski

Faculty Publications

This research supports the hypothesis that the Trust Vector model can be modified to fit the CyberCraft Initiative, and that there are limits to the utility of historical data. This research proposed some modifications and expansions to the Trust Model Vector, and identified areas for future research.

On The Steering Of Sound Energy Through A Supercritical Plate By A Near-Field Transducer Array, Brian E. Anderson, Stephen A. Hambric, Jack W. Hughes

Faculty Publications

The ability to direct sound energy through the flexural vibrations of a submerged plate at various angles of incidence using a near-field transducer array is investigated. An alumina bar is placed in front of a one-dimensional, eight-element transducer array, between the array and the water. Operating in a receive mode, data were taken as a function of angle of incidence and compared to data taken without the presence of the alumina bar. The array was also operated in transmit mode and results were compared to corresponding receive mode data, showing that reciprocity holds. Results show that in fact sound energy …

Vacuum Stress-Energy Density And Its Gravitational Implications, Ricardo Estrada, Stephen A. Fulling, Lev Kaplan, Klaus Kirsten, Zhonghai Liu, Kimball A. Milton

Faculty Publications

In nongravitational physics the local density of energy is often regarded as merely a bookkeeping device; only total energy has an experimental meaning - and it is only modulo a constant term. But in general relativity the local stress-energy tensor is the source term in Einstein's equation. In closed universes, and those with Kaluza-Klein dimensions, theoretical consistency demands that quantum vacuum energy should exist and have gravitational effects, although there are no boundary materials giving rise to that energy by van der Waals interactions. In the lab there are boundaries, and in general the energy density has a nonintegrable singularity …

Co2 Fixation Kinetics Of Halothiobacillus Neapolitanus Mutant Carboxysomes Lacking Carbonic Anhydrase Suggest The Shell Acts As A Diffusional Barrier For Co2, Zhicheng Dou, Sabine Heinhorst, Eric B. Williams, C. Daniel Murin, Jessup M. Shively, Gordon C. Cannon

Faculty Publications

The widely accepted models for the role of carboxysomes in the carbon-concentrating mechanism of autotrophic bacteria predict the carboxysomal carbonic anhydrase to be a crucial component. The enzyme is thought to dehydrate abundant cytosolic bicarbonate and provide ribulose 1.5-bisphosphate carboxylase/oxygenase (RubisCO) sequestered within the carboxysome with sufficiently high concentrations of its substrate, CO₂, to permit its efficient fixation onto ribulose 1,5-bisphosphate. In this study, structure and function of carboxysomes purified from wild type Halothiobacillus neapolitanus and from a high CO₂-requiring mutant that is devoid of carboxysomal carbonic anhydrase were compared. The kinetic constants for the carbon …

Metallicity And Effective Temperature Of The Secondary Or Rs Ophicuhi, R. L. Pearson Iii, Ya. V. Pavlenko, A. Evans, T. Kerr, L. Yakovina, C. E. Woodward, D. Lynch, R. Rudy, R. W. Russell

Faculty Publications

Context. The recurrent nova RS Ophiuchi undergoes nova eruptions every 10-20 years as a result of thermonuclear runaway on the surface of a white dwarf close to the Chandrasekhar limit. Both the progress of the eruption and its aftermath depend on the (poorly known) composition of the red giant in the RS Oph system. Aims. Our aim is to understand better the effect of the giant secondary on the recurrent nova eruption. Methods. Synthetic spectra were computed for a grid of M-giant model atmospheres having a range of effective temperatures 3200 < Teff < 4400 K, gravities 0 < log g < 1 and abundances -4 < [Fe/H] < 0.5, and fit to infrared spectra of RS Oph as it returned to quiescence after its 2006 eruption. We have modelled the infrared spectrum in the range 1.4-2.5µm to determine metallicity and effective temperature of the red giant. Results. We find Teff= 4100 ±100 K, log g = 0.0 ±0.5, [Fe/H] = 0.0 ±0.5, [C/H] = -0.8 ±0.2, [N/H] = +0.6 ±0.3 in the atmosphere of the secondary, and demonstrate that inclusion of some dust "veiling" in the spectra cannot improve our fits.

Γ-Commuting Triples Of Positive Definite Matrices And Midpoint Equations On Unitary Matrices, Jimmie Lawson, Yongdo Lim

Faculty Publications

Triples of positive definite matrices that can be transformed to a commuting triple by a congruence transformation are called Γ-commuting. In this paper we give various descriptions and characterizations of Γ-commuting triples and particularly focus on those involving the geometric mean and midpoint equations on a generating set of the special unitary group. © 2007 Elsevier Inc. All rights reserved.

Asymmetry Of Recoil Protons In Neutron Β Decay, Vladimir Gudkov

Faculty Publications

A complete analysis of proton recoil asymmetry in neutron decay in the first order of radiative and recoil corrections is presented. The possible contributions from new physics are calculated in terms of low energy coupling constants, and the sensitivity of the measured asymmetry to models beyond the Standard Model are discussed.

W(H)Ither Fossils? Studying Morphological Character Evolution In The Age Of Molecular Sequences, Elizabeth J. Hermsen, Jonathan R. Hendricks

Faculty Publications

A major challenge in the post-genomics era will be to integrate molecular sequence data from extant organisms with morphological data from fossil and extant taxa into a single, coherent picture of phylogenetic relationships; only then will these phylogenetic hypotheses be effectively applied to the study of morphological character evolution. At least two analytical approaches to solving this problem have been utilized: (1) simultaneous analysis of molecular sequence and morphological data with fossil taxa included as terminals in the analysis, and (2) the molecular scaffold approach, in which morphological data are analyzed over a molecular backbone (with constraints that force extant …

Sub-Mesoscale Ocean Vortex Trains In The Luzon Strait, Quanan Zheng, Hui Lin, Junmin Meng, Xiaomin Hu, Y. Tony Song, Yuanzhi Zhang, Chunyan Li

Faculty Publications

This study uses the Argos satellite-tracked surface drifter trajectory data and ENVISAT (European satellite) ASAR (advanced synthetic aperture radar) images to illustrate the ocean vortex trains (OVT) in the Luzon Strait. Two cases that occurred in the northwest of Babuyan Island are observed. The first train of three cyclonic vortices showed up on drifter trajectories from 20° to 20.5°N and from 120° to 121°E, and the second, consisting of five pairs of cyclonic-anticyclonic vortices, occurred on the upstream side of the first one from 19.5° to 20.0°N and from 121.0° to 122.0°E and showed up on the ASAR images acquired …

Hypogenic Speleogenesis Within Seven Rivers Evaporites: Coffee Cave, Eddy County, New Mexico, Kevin W. Stafford, Lewis Land, Alexander Klimchouk

Faculty Publications

Coffee Cave, located in the lower Pecos region of southeastern New Mexico, illustrates processes of hypogenic speleogenesis in the middle Permian Seven Rivers Formation. Coffee Cave is a rectilinear gypsum maze cave with at least four stratigraphically-distinct horizons of development. Morphological features throughout the cave provide unequivocal evidence of hypogenic ascending speleogenesis in a confined aquifer system driven by mixed (forced and free) convection. Morphologic features in individual cave levels include a complete suite that defines original rising flow paths, ranging from inlets for hypogenic fluids (feeders) through transitional forms (rising wall channels) to ceiling half-tube flow features and fluid …

Hopf Algebras Of Dimension Pq, Ii, Siu Hung Ng

Faculty Publications

Let H be a Hopf algebra of dimension pq over an algebraically closed field of characteristic zero, where p, q are odd primes with p < q ≤ 4 p + 11. We prove that H is semisimple and thus isomorphic to a group algebra, or the dual of a group algebra. © 2007 Elsevier Inc. All rights reserved.

Transmission Through A Thick Periodic Slab, Karim Ramdani, Stephen Shipman

Faculty Publications

For the scalar wave equation in periodic structures, we establish rigorously the manifestation of a spectral bandgap as a frequency interval of exponentially small transmission of energy through a slab of the crystal when the thickness of the slab tends to infinity. We extend the result to slabs that contain a planar defect for frequencies that do not coincide with guided mode frequencies for the defect. For one-dimensional crystals, we prove that the transmission approaches a nonzero value at guided mode frequencies and give an explicit formula for the transmission. The main analytical tool in the multidimensional case is the …

Skill Evaluation In Women's Volleyball, Lindsay W. Florence, Gilbert W. Fellingham, Pat R. Vehrs, Nina P. Mortensen

Faculty Publications

The Brigham Young University Women's Volleyball Team recorded and rated all skills (pass, set, attack, etc.) and recorded rally outcomes (point for BYU, rally continues, point for opponent) for the entire 2006 home volleyball season. Only sequences of events occurring on BYU's side of the net were considered. Events followed one of these general patterns: serve-outcome, pass-set-attack-outcome, or block-dig-set-attack-outcome. These sequences of events were assumed to be first-order Markov chains where the quality of each contact depended only on the quality of the previous contact but not explicitly on contacts further removed in the sequence. We represented these sequences in …

Substantive Due Process Limits On Punitive Damage Awards: "Morals Without Technique"?, F. Patrick Hubbard

Faculty Publications

In a series of cases decided over the last two decades, the Supreme Court has used the Due Process Clause to establish a procedural and substantive framework for awarding punitive damages. Initially, the substantive aspects of this framework were sufficiently clear and flexible that they required little change in the system and probably generated a helpful level of debate and uniformity as to some basic requirements for awards. However, in BMW of North America, Inc. v. Gore, the Court adopted an approach characterized by a lack of clarity and consistency, an inadequate basis in theory and policy, and ad hoc …

Loop Quantization Of Spherically Symmetric Midi-Superspaces: The Interior Problem, Miguel Campiglia, Rodolfo Gambini, Jorge Pullin

Faculty Publications

We continue the study of spherically symmetric vacuum space-times in loop quantum gravity by treating the interior of a black hole. We start from a midi-superspace approach, but a simple gauge fixing leads to a Kantowski-Sachs form for the variables. We show that one can solve the quantum theory exactly in the (periodic) connection representation, including the inner product. The evolution can be solved exactly by de-parameterizing the theory and can be easily interpreted as a semi-classical evolution plus quantum corrections. A relational evolution can also be introduced in a precise manner, suggesting what may happen in situations where it …

Three- And Four-Jet Final States In Photoproduction At Hera, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, G. Sartorelli, A. Zichichi

Faculty Publications

Three- and four-jet final states have been measured in photoproduction at HERA using the ZEUS detector with an integrated luminosity of 121 pb -1. The results are presented for jets with transverse energy E Tjet > 6 GeV and pseudorapidity | η jet | < 2.4, in the kinematic region given by the virtuality of the photon Q 2 < 1 GeV 2 and the inelasticity 0.2 ≤ y ≤ 0.85 and in two mass regions defined as 25 ≤ M n j < 50 GeV and M n j ≥ 50 GeV, where M n j is the invariant mass of the n-jet system. The four-jet photoproduction cross section has been measured for the first time and represents the highest-order process studied at HERA. Both the three- and four-jet cross sections have been compared with leading-logarithmic parton-shower Monte Carlo models, with and without multi-parton interactions. The three-jet cross sections have been compared to an O (α α s2) perturbative QCD calculation. © 2007 Elsevier B.V. All rights reserved.

Comment On “Contact Conditions For The Charge In The Theory Of The Electrical Double Layer”, Douglas Henderson, L. B. Bhuiyan

Faculty Publications

Exact results in any field, including statistical mechanics, are both aesthetically pleasing and very valuable in assessing theoretical approximations.

Gene Rearrangement Analysis And Ancestral Order Inference From Chloroplast Genomes With Inverted Repeat, Feng Yue, Liying Cui, Claude W. Depamphilis, Bernard M.E. Moret, Jijun Tang

Faculty Publications

Background
Genome evolution is shaped not only by nucleotide substitutions, but also by structural changes including gene and genome duplications, insertions, deletions and gene order rearrangements. The most popular methods for reconstructing phylogeny from genome rearrangements include GRAPPA and MGR. However these methods are limited to cases where equal gene content or few deletions can be assumed. Since conserved duplicated regions are present in many chloroplast genomes, the inference of inverted repeats is needed in chloroplast phylogeny analysis and ancestral genome reconstruction.

Results
We extend GRAPPA and develop a new method GRAPPA-IR to handle chloroplast genomes. A test of GRAPPA-IR …

Search For Gravitational Waves Associated With 39 Gamma-Ray Bursts Using Data From The Second, Third, And Fourth Ligo Runs, B. Abbott, R. Abbott, R. Adhikari, J. Agresti, P. Ajith, B. Allen, R. Amin, S. B. Anderson, W. G. Anderson, M. Arain, M. Araya, H. Armandula, M. Ashley, S. Aston, P. Aufmuth, C. Aulbert, S. Babak, S. Ballmer, H. Bantilan, B. C. Barish, C. Barker, D. Barker, B. Barr, P. Barriga, M. A. Barton, K. Bayer, K. Belczynski, S. J. Berukoff, J. Betzwieser, P. T. Beyersdorf, B. Bhawal, Tiffany Z. Summerscales

Faculty Publications

We present the results of a search for short-duration gravitational-wave bursts associated with 39 gamma-ray bursts (GRBs) detected by gamma-ray satellite experiments during LIGO's S2, S3, and S4 science runs. The search involves calculating the crosscorrelation between two interferometer data streams surrounding the GRB trigger time. We search for associated gravitational radiation from single GRBs, and also apply statistical tests to search for a gravitational-wave signature associated with the whole sample. For the sample examined, we find no evidence for the association of gravitational radiation with GRBs, either on a single-GRB basis or on a statistical basis. Simulating gravitational-wave bursts …

Accelerating Corpus Annotation Through Active Learning, George Busby, Marc Carmen, James Carroll, Robbie Haertel, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi

Faculty Publications

PDF of Powerpoint Presentation on accelerating corpus annotation through active learning. This presentation was given at the Conference of the American Association for Corpus Linguistics in 2008.

Analysis Of Canonical Chinese Antonym Co-Occurrence, Eric K. Ringger, Guohui Liu, Shiping Liu, Xingfu Wang

Faculty Publications

PDF of Powerpoint Presentation on canonical Chinese antonym co-occurrence. This presentation was given at the Conference of the American Association for Corpus Linguistics in 2008.

Compiling And Annotating A Syriac Corpus, George Busby, James Carroll, Marc Carmen, Carl Griffin, Robbie Haertel, Kristian Heal, Joshua Heaton, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi, David Taylor

Faculty Publications

PDF of Powerpoint Presentation on compiling and annotating a Syriac corpus. This presentation was given at the Conference of the American Association for Corpus Linguistics in 2008.

Molecular Dynamics Simulations Of Biotin Carboxylase, Sten O.Nilsson Lili, Jiali Gao, Grover L. Waldrop

Faculty Publications

Biotin carboxylase catalyzes the ATP-dependent carboxylation of biotin and is one component of the multienzyme complex acetyl-CoA carboxylase that catalyzes the first committed step in fatty acid synthesis in all organisms. Biotin carboxylase from Escherichia coli, whose crystal structures with and without ATP bound have been determined, has served as a model system for this component of the acetyl-CoA carboxylase complex. The two crystal structures revealed a large conformational change of one domain relative to the other domains when ATP is bound. Unfortunately, the crystal structure with ATP bound was obtained with an inactive site-directed mutant of the enzyme. As …

A Natural Series For The Natural Logarithm, Oliver T. Dasbach

Faculty Publications

Rodriguez Villegas expressed the Mahler measure of a polynomial in terms of an infinite series. Luck's combinatorial L2-torsion leads to similar series expressions for the Gromov norm of a knot complement. In this note we show that those formulae yield interesting power series expansions for the logarithm function. This generalizes an infinite series of Lehmer for the natural logarithm of 4.