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Infinite Antichains Of Matroids With Characteristic Set {P}, James Oxley, Charles Semple, Dirk Vertigan, Geoff Whittle Jun 2002

Infinite Antichains Of Matroids With Characteristic Set {P}, James Oxley, Charles Semple, Dirk Vertigan, Geoff Whittle

Faculty Publications

For each prime p, we construct an infinite antichain of matroids in which each matroid has characteristic set {p}. For p = 2, each of the matroids in our antichain is an excluded minor for the class of matroids representable over the rationals. © 2002 Elsevier Science B.V. All rights reserved.

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Note On The Derivative Of The Hyperbolic Cotangent, G. W. Ford, R. F. O'Connell May 2002

Note On The Derivative Of The Hyperbolic Cotangent, G. W. Ford, R. F. O'Connell

Faculty Publications

In a letter to Nature (Ford G W and O'Connell R F 1996 Nature 380 113) we presented a formula for the derivative of the hyperbolic cotangent that differs from the standard one in the literature by an additional term proportional to the Dirac delta function. Since our letter was necessarily brief, shortly after its appearance we prepared a more extensive unpublished note giving a detailed explanation of our argument. Since this note has been referenced in a recent article (Estrada R and Fulling S A 2002 J. Phys. A: Math. Gen. 35 3079) we think it appropriate that it …

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Review Of Tuxedo Park, Michael F. Russo May 2002

Review Of Tuxedo Park, Michael F. Russo

Faculty Publications

No abstract provided.

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Laplace Transform Of Spherical Bessel Functions, A. Ludu, R. F. O'Connell May 2002

Laplace Transform Of Spherical Bessel Functions, A. Ludu, R. F. O'Connell

Faculty Publications

We provide a simple analytic formula in terms of elementary functions for the Laplace transform j̃l(p) of the spherical Bessel function than that appearing in the literature, and we show that any such integral transform is a polynomial of order l in the variable p with constant coefficients for the first l - 1 powers, and with an inverse tangent function of argument 1/p as the coefficient of the power l. We apply this formula for the Laplace transform of the memory function related to the Langevin equation in a one-dimensional Debye model.

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Design Of Functionally Graded Composite Structures In The Presence Of Stress Constraints, Robert Lipton Apr 2002

Design Of Functionally Graded Composite Structures In The Presence Of Stress Constraints, Robert Lipton

Faculty Publications

In this work new homogenization results are used to introduce a methodology for the design of structural components made from composite materials in the presence of stress constraints. A numerical method is developed for finding functionally graded materials that provide the maximum torsional rigidity while keeping the mean square stress inside the composite structure below a prescribed level. © 2002 Elsevier Science Ltd. All rights reserved.

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Unavoidable Minors Of Graphs Of Large Type, John Dittmann, Bogdan Oporowski Apr 2002

Unavoidable Minors Of Graphs Of Large Type, John Dittmann, Bogdan Oporowski

Faculty Publications

In this paper, we study one measure of complexity of a graph, namely its type. The type of a graph G is defined to be the minimum number n such that there is a sequence of graphs G = G0, G1,...,Gn, where Gi is obtained by contracting one edge in or deleting one edge from each block of G/_i, and where G is edgeless. We show that a 3-connected graph has large type if and only if it has a minor isomorphic to a large fan. Furthermore, we show that if a graph has large type, then it has a …

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Group Actions On Central Simple Algebras, Daniel S. Sage Apr 2002

Group Actions On Central Simple Algebras, Daniel S. Sage

Faculty Publications

Let G be a group, F a field, and A a finite-dimensional central simple algebra over F on which G acts by F-algebra automorphisms. We study the subalgebras and ideals of A which are preserved by the group action. We prove a structure theorem and two classification theorems for invariant subalgebras under suitable hypotheses on A. We illustrate these results in the case of compact connected Lie groups and give some other applications. We also classify invariant ideals. © 2002 Elsevier Science (USA).

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Faculty Senate Resolution 02-05, Louisiana State University And Agricultural & Mechanical College Mar 2002

Faculty Senate Resolution 02-05, Louisiana State University And Agricultural & Mechanical College

LSU Faculty Senate Publications

Faculty Senate Resolution regarding listing a second major on the transcript of a student obtaining one Bachelor's Degree, adopted on March 7, 2002.

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Some Cyclic Covers Of Complements Of Arrangements, Daniel C. Cohen, Peter Orlik Feb 2002

Some Cyclic Covers Of Complements Of Arrangements, Daniel C. Cohen, Peter Orlik

Faculty Publications

Motivated by the Milnor fiber of a central arrangement, we study the cohomology of a family of cyclic covers of the complement of an arbitrary arrangement. We give an explicit proof of the polynomial periodicity of the Betti numbers of the members of this family of cyclic covers. © 2002 Elsevier Science B.V. All rights reserved.

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Lsu General Catalog 2002-2003, Louisiana State University And Agricultural And Mechanical College Jan 2002

Lsu General Catalog 2002-2003, Louisiana State University And Agricultural And Mechanical College

LSU General Catalog

The LSU General Catalog describes all undergraduate and graduate departments and programs with degree requirements and courses offered for each one. The General Catalog includes information on registration and financial aid as well as academic services offered to all students.

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Single-Photon Quantum-Nondemolition Detectors Constructed With Linear Optics And Projective Measurements, Pieter Kok, Hwang Lee, Jonathan P. Dowling Jan 2002

Single-Photon Quantum-Nondemolition Detectors Constructed With Linear Optics And Projective Measurements, Pieter Kok, Hwang Lee, Jonathan P. Dowling

Faculty Publications

Optical quantum-nondemolition devices can provide essential tools for quantum information processing. Here, we describe several optical interferometers that signal the presence of a single photon in a particular input state without destroying it. We discuss both entanglement-assisted and nonentanglement-assisted interferometers, with ideal and realistic detectors. We found that the existing detectors with 88% quantum efficiency and single-photon resolution can yield output fidelities of up to 89%, depending on the input state. Furthermore, we construct expanded protocols to perform quantum-nondemolition detections of single photons that leave the polarization invariant. For detectors with 88% efficiency, we found polarization-preserving output fidelities of up …

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The Effect Of Reactor Geometry On Frontal Polymerization Spin Modes, John A. Pojman, Jonathan Masere, Enrico Petretto, Mauro Rustici, Do Sung Huh, Min Suk Kim, Vladimir Volpert Jan 2002

The Effect Of Reactor Geometry On Frontal Polymerization Spin Modes, John A. Pojman, Jonathan Masere, Enrico Petretto, Mauro Rustici, Do Sung Huh, Min Suk Kim, Vladimir Volpert

Faculty Publications

Using reactors of different sizes and geometries the dynamics of the frontal polymerization of 1,6-hexanediol diacrylate (HDDA) and pentaerythritol tetraacrylate (PETAC), with ammonium persulfate as the initiator were studied. For this system, the frontal polymerization exhibits complex behavior that depends on the ratio of the monomers. For a particular range of monomers concentration, the polymerization front becomes nonplanar, and spin modes appear. By varying the reactor diameter, we experimentally confirmed the expected shift of the system to a greater number of "hot spots" for larger diameters. For square test tubes a "zig-zag" mode was observed for the first time in …

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Packing Cycles In Graphs, Guoli Ding, Wenan Zang Jan 2002

Packing Cycles In Graphs, Guoli Ding, Wenan Zang

Faculty Publications

A graph G is called cycle Mengerian (CM) if for all nonnegative integral function w defined on V(G), the maximum number of cycles (repetition is allowed) in G such that each vertex v is used at most w(v) times is equal to the minimum of ∑ {w(x) : x ∈ X}, where the minimum is taken over all X ⊆ V(G) such that deleting X from G results in a forest. The purpose of this paper is to characterize all CM graphs in terms of forbidden structures. As a corollary, we prove that if the fractional version of the above …

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Compactification Of Classical Groups, Hongyu He Jan 2002

Compactification Of Classical Groups, Hongyu He

Faculty Publications

No abstract provided.

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Chapter 23 Optimal Design Of Gradient Fields With Applications To Electrostatics, Robert Lipton, Ani P. Velo Jan 2002

Chapter 23 Optimal Design Of Gradient Fields With Applications To Electrostatics, Robert Lipton, Ani P. Velo

Faculty Publications

No abstract provided.

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On Matroids Of Branch-Width Three, Rhiannon Hall, James Oxley, Charles Semple, Geoff Whittle Jan 2002

On Matroids Of Branch-Width Three, Rhiannon Hall, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

For all positive integers k, the class Bk of matroids of branch-width at most k is minor-closed. When k is 1 or 2, the class Bk is, respectively, the class of direct sums of loops and coloops, and the class of direct sums of series-parallel networks. B3 is a much richer class as it contains infinite antichains of matroids and is thus not well-quasi-ordered under the minor order. In this paper, it is shown that, like B1 and B2, the class B3 can be characterized by a finite list of excluded minors. © 2002 Elsevier Science (USA).

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Totally Free Expansions Of Matroids, James Geelen, James Oxley, Dirk Vertigan, Geoff Whittle Jan 2002

Totally Free Expansions Of Matroids, James Geelen, James Oxley, Dirk Vertigan, Geoff Whittle

Faculty Publications

The aim of this paper is to give insight into the behaviour of inequivalent representations of 3-connected matroids. An element x of a matroid M is fixed if there is no extension M′ of M by an element x′ such that {x, x′} is independent and M′ is unaltered by swapping the labels on x and x′. When x is fixed, a representation of M.\x extends in at most one way to a representation of M. A 3-connected matroid N is totally free if neither N nor its dual has a fixed element whose deletion is a series extension of …

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Mixed-Mode Shell-Model Theory For Nuclear Structure Studies, V. G. Gueorguiev, W. E. Ormand, C. W. Johnson, J. P. Draayer Jan 2002

Mixed-Mode Shell-Model Theory For Nuclear Structure Studies, V. G. Gueorguiev, W. E. Ormand, C. W. Johnson, J. P. Draayer

Faculty Publications

We introduce a shell-model theory that combines traditional spherical states, which yield a diagonal representation of the usual single-particle interaction, with collective configurations that track deformations, and test the validity of this mixed-mode, oblique-basis shell-model scheme on [Formula Presented] The correct binding energy (within 2% of the full-space result) as well as low-energy configurations that have greater than 90% overlap with full-space results are obtained in a space that spans less than 10% of the full space. The results suggest that a mixed-mode shell-model theory may be useful in situations where competing degrees of freedom dominate the dynamics and full-space …

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Hyperbolicity Of The Baumgarte-Shapiro-Shibata-Nakamura System Of Einstein Evolution Equations, Olivier Sarbach, Gioel Calabrese, Jorge Pullin, Manuel Tiglio Jan 2002

Hyperbolicity Of The Baumgarte-Shapiro-Shibata-Nakamura System Of Einstein Evolution Equations, Olivier Sarbach, Gioel Calabrese, Jorge Pullin, Manuel Tiglio

Faculty Publications

We discuss an equivalence between the Baumgarte-Shapiro-Shibata-Nakamura (BSSN) formulation of the Einstein evolution equations, a subfamily of the Kidder-Scheel-Teukolsky formulation, and other strongly or symmetric hyperbolic first order systems with fixed shift and densitized lapse. This allows us to show under which conditions the BSSN system is, in a sense to be discussed, hyperbolic. This desirable property may account in part for the empirically observed better behavior of the BSSN formulation in numerical evolutions involving black holes. © 2002 The American Physical Society.

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Finite Spin-Foam-Based Theory Of Three- And Four-Dimensional Quantum Gravity, Rodolfo Gambini, Jorge Pullin Jan 2002

Finite Spin-Foam-Based Theory Of Three- And Four-Dimensional Quantum Gravity, Rodolfo Gambini, Jorge Pullin

Faculty Publications

Starting from Ooguri's construction for BF theory in three (and four) dimensions, we show how to construct a well defined theory with an infinite number of degrees of freedom. The spin network states that are kept invariant by the evolution operators of the theory are exact solutions of the Hamiltonian constraint of quantum gravity proposed by Thiemann. The resulting theory is the first example of a well defined, finite, consistent, spin-foam-based theory in a situation with an infinite number of degrees of freedom. Since it solves the quantum constraints of general relativity it is also a candidate for a theory …

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Close Limit Evolution Of Kerr-Schild Type Initial Data For Binary Black Holes, Olivier Sarbach, Manuel Tiglio, Jorge Pullin Jan 2002

Close Limit Evolution Of Kerr-Schild Type Initial Data For Binary Black Holes, Olivier Sarbach, Manuel Tiglio, Jorge Pullin

Faculty Publications

We eyolve the binary black hole initial data family proposed by Bishop et al. in the limit in which the black holes are close to each other. We present an exact solution of the linearized initial value problem based on their proposal and make use of a recently introduced generalized formalism for studying perturbations of Schwarzschild black holes in arbitrary coordinates to perform the evolution. We clarify the meaning of the free parameters of the initial data family through the results for the radiated energy and waveforms from the black hole collision. © 2002 The American Physical Society.

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Semiparametric Maximum Likelihood Estimates Of Spatial Dependence, R. Kelley Pace, James P. Lesage Jan 2002

Semiparametric Maximum Likelihood Estimates Of Spatial Dependence, R. Kelley Pace, James P. Lesage

Faculty Publications

We semiparametrically model spatial dependence via a combination of simpler weight matrices (termed spatial basis matrices) and fit this model via maximum likelihood. Estimation of the model relies on the intuition that bounds to the log-determinant term in the log-likelihood can provide penalties to overfitting both the level and pattern of spatial dependence. By relying on symmetric and doubly stochastic spatial basis matrices that reflect different weight specifications assigned to neighboring observations, we are able to derive a mathematical expression for bounds on the log-determinant term that appears in the likelihood function. These bounds can be conveniently calculated allowing us …

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Quantification Of The Spatial Gradient Of Local Volume Fraction From Tomography Images, Yongping Wang Jan 2002

Quantification Of The Spatial Gradient Of Local Volume Fraction From Tomography Images, Yongping Wang

LSU Master's Theses

Asphalt concrete has three constituents: aggregate, asphalt binder and air voids. In the mixture, aggregates serve as a skeleton of the mixture; asphalt serves as a binder to hold the aggregates together; and air voids prevent asphalt concrete from bleeding to avoid plastic mixes. The properties of asphalt concrete are controlled by the interaction of these three components. In asphalt concrete, asphalt binder, voids and aggregates are not uniformly distributed. The local volume fractions of these constituents vary with spatial locations. As a result, there exist a spatial gradient of the local volume fractions between two locations. Due to the …

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Surfactant-Induced Relative Permeability Modifications For Oil Recovery Enhancement, Subhash C. Ayirala Jan 2002

Surfactant-Induced Relative Permeability Modifications For Oil Recovery Enhancement, Subhash C. Ayirala

LSU Master's Theses

Surfactants have been considered for enhanced oil recovery by reduced oil-water interfacial tension. However, these surfactants may enhance oil recovery via wettability alteration as well. This study experimentally determines the influence of surfactant type and concentration on oil recovery, oil-water relative permeabilities and wettability in reservoir rocks. Several coreflood experiments were conducted using Yates reservoir fluids in Berea rocks and two types of surfactants (nonionic and anionic) in varying concentrations. A coreflood simulator was used to calculate oil-water relative permeabilities by history matching recovery and pressure drop measured during the corefloods. These relative permeability variations were interpreted using Craig's rules-of-thumb …

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Decentralized And Adaptive Sensor Data Routing, Mengxia Zhu Jan 2002

Decentralized And Adaptive Sensor Data Routing, Mengxia Zhu

LSU Master's Theses

Wireless sensor network (WSN) has been attracting research efforts due to the rapidly increasing applications in military and civilian fields. An important issue in wireless sensor network is how to send information in an efficient and adaptive way. Information can be directly sent back to the base station or through a sequence of intermediate nodes. In the later case, it becomes the problem of routing. Current routing protocols can be categorized into two groups, namely table-drive (proactive) routing protocols and source-initiated on-demand (reactive) routing. For ad hoc wireless sensor network, routing protocols must deal with some unique constraints such as …

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Longitudinal Dispersion Coefficient In Single-Channel Streams, Z. Q. Deng, L. Bengtsson, V. P. Singh, D. D. Adrian Jan 2002

Longitudinal Dispersion Coefficient In Single-Channel Streams, Z. Q. Deng, L. Bengtsson, V. P. Singh, D. D. Adrian

Faculty Publications

Using a new channel shape equation for straight channels and a more versatile channel shape or local flow depth equation for natural streams a method is developed for prediction of the longitudinal dispersion coefficient in single-channel natural streams, including straight and meandering ones. The method involves derivation of a new triple integral expression for the longitudinal dispersion coefficient and development of an analytical method for prediction of this coefficient in natural streams. The proposed method is verified using 70 sets of field data collected from 30 streams in the United States ranging from straight manmade canals to sinuous natural rivers. …

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An Economic Analysis Of Pre-Harvesting Marketing Strategies And Financial Performance, Manuel Duarte Filipe Jan 2002

An Economic Analysis Of Pre-Harvesting Marketing Strategies And Financial Performance, Manuel Duarte Filipe

LSU Master's Theses

Risk is an important concern in the management of a farm business. The rising input prices along with the variability in the farm commodity prices may result in a risk environment. Government programs have generally provided income support to farmers. However, there has been considerable discussion regarding this support in recent years. The farm act of 2002 and farm bill of 1999 are good examples of such discussions. These uncertainties emphasize the need to improve information for farm's income risk management, and make some one ask if there is not out there any alternative way of managing income risk besides …

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Characterization Of The Lower Atoka Formation, Arkoma Basin, Central Arkansas, Kelly R. Lagrange Jan 2002

Characterization Of The Lower Atoka Formation, Arkoma Basin, Central Arkansas, Kelly R. Lagrange

LSU Master's Theses

The Carboniferous Lower Atoka outcrops in the Arkoma Basin of Central Arkansas contain turbidite deposits in a channelized and unchannelized submarine fan setting. The objectives of the study were to determine depositional characteristics and reservoir performance of these fine-grained submarine fan deposits. Four outcrops (Highway 5, Perryville, Chula, and Danville) were studied and described in detail emphasizing sedimentary facies, vertical succession of beds, sedimentary structures, and other small-scaled features that cannot be resolved in subsurface deposits. Five distinct sedimentary facies were recognized: Facies A - massive sandstones, Facies B - thin-bedded sandstones with a mudstone drape, Facies C - interbedded …

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An Integrated Approach To Stormwater Management In The Coastal Zone, Clotho Alexis Spinner Jan 2002

An Integrated Approach To Stormwater Management In The Coastal Zone, Clotho Alexis Spinner

LSU Master's Theses

Undeveloped lands are inherently capable of handling the precipitation rates and severe storm events of a given area. As our communities continue to grow and expand, the stormwater management capabilities of an area’s natural systems will be impacted. Without thoughtful intervention, existing natural systems will be overwhelmed to the point of dysfunction, an unfortunate circumstance that has been the case in some of this country’s more urbanized areas. The main objective of this thesis is to demonstrate the process of applying an integrated greenway stormwater management system as an alternative approach to managing the present and future stormwater needs of …

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Reliability Of Wavelet Analysis Of Heart Rate Variability During Rest And Exercise, Deborah Jean Stone Jan 2002

Reliability Of Wavelet Analysis Of Heart Rate Variability During Rest And Exercise, Deborah Jean Stone

LSU Master's Theses

The reliability of wavelet analysis (DWT), of heart rate variability during rest and exercise was examined for this study. All twenty-three participants visited the lab on two separate occasions no less than four weeks apart. All twenty-three participants were subjected to the spontaneous breathing (SB1), and HG60 exercise condition. Of those twenty-three participants, nine performed the HG20 exercise condition as well. It was found that during the SB1 condition, the R-R intervals were fairly reliable between days. However, the reliability of all the HRV parameters (SDNN, spectral components and wavelet components) were quite poor. Interestingly, however, during HG20, the reliability …

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