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Inflationary Cosmology And Quantization Ambiguities In Semiclassical Loop Quantum Gravity, Martin Bojowald, James E. Lidsey, David J. Mulryne, Parampreet Singh, Reza Tavakol Jan 2004

Inflationary Cosmology And Quantization Ambiguities In Semiclassical Loop Quantum Gravity, Martin Bojowald, James E. Lidsey, David J. Mulryne, Parampreet Singh, Reza Tavakol

Faculty Publications

In loop quantum gravity, modifications to the geometrical density cause a self-interacting scalar field to accelerate away from a minimum of its potential. In principle, this mechanism can generate the conditions that subsequently lead to slow-roll inflation. The consequences for this mechanism of various quantization ambiguities arising within loop quantum cosmology are considered. For the case of a quadratic potential, it is found that some quantization procedures are more likely to generate a phase of slow-roll inflation. In general, however, loop quantum cosmology is robust to ambiguities in the quantization and extends the range of initial conditions for inflation. © …

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Climbing Bloom's Ladder, Isiah M. Warner Jan 2004

Climbing Bloom's Ladder, Isiah M. Warner

Faculty Publications

No abstract provided.

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Excluding Any Graph As A Minor Allows A Low Tree-Width 2-Coloring, Matt Devos, Guoli Ding, Bogdan Oporowski, Daniel P. Sanders, Bruce Reed, Paul Seymour, Dirk Vertigan Jan 2004

Excluding Any Graph As A Minor Allows A Low Tree-Width 2-Coloring, Matt Devos, Guoli Ding, Bogdan Oporowski, Daniel P. Sanders, Bruce Reed, Paul Seymour, Dirk Vertigan

Faculty Publications

This article proves the conjecture of Thomas that, for every graph G, there is an integer k such that every graph with no minor isomorphic to G has a 2-coloring of either its vertices or its edges where each color induces a graph of tree-width at most k. Some generalizations are also proved. © 2003 Elsevier Inc. All rights reserved.

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Multiplicative Renormalization And Generating Functions Ii, Nobuhiro Asai, Izumi Kubo, Hui Hsiung Kuo Jan 2004

Multiplicative Renormalization And Generating Functions Ii, Nobuhiro Asai, Izumi Kubo, Hui Hsiung Kuo

Faculty Publications

Let μ be a probability measure on the real line with finite moments of all orders. Suppose the linear span of polynomials is dense in L 2(μ). Then there exists a sequence {Pn} n=0∞ orthogonal polynomials with respect to μ such that Pn is a polynomial of degree n with leading coefficient 1 and the equality (x -αn)Pn(x) = Pn+1(x) + wnPn-1(x) holds, where αn and w n are Szegö-Jacobi parameters. In this paper we use the concepts of pre-generating function, multiplicative renormalization, and generating function to derive {Pn,αn,wn} from a given μ Two types of pre-generating functions are studied. …

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Seiberg-Witten Vanishing Theorem For S1-Manifolds With Fixed Points, Scott Baldridge Jan 2004

Seiberg-Witten Vanishing Theorem For S1-Manifolds With Fixed Points, Scott Baldridge

Faculty Publications

We show that the Seiberg-Witten invariant is zero for all smooth 4-manifolds with b >1 that admit circle actions having at least one fixed point. We also show that all symplectic 4-manifolds that admit (possibly nonsymplectic) circle actions with fixed points are rational or ruled, and thus admit a symplectic circle action. +

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The Structure Of The 3-Separations Of 3-Connected Matroids, James Oxley, Charles Semple, Geoff Whittle Jan 2004

The Structure Of The 3-Separations Of 3-Connected Matroids, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

Tutte defined a k-separation of a matroid M to be a partition (A,B) of the ground set of M such that A , B ≥k and r(A)+r(B)-r(M)

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Fork-Decompositions Of Matroids, Rhiannon Hall, James Oxley, Charles Semple, Geoff Whittle Jan 2004

Fork-Decompositions Of Matroids, Rhiannon Hall, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

One of the central problems in matroid theory is Rota's conjecture that, for all prime powers q, the class of GF(q)-representable matroids has a finite set of excluded minors. This conjecture has been settled for q ≤ 4 but remains open otherwise. Further progress towards this conjecture has been hindered by the fact that, for all q ≥ 5, there are 3-connected GF(q)-representable matroids having arbitrarily many inequivalent GF(q)-representations. This fact refutes a 1988 conjecture of Kahn that 3-connectivity would be strong enough to ensure an absolute bound on the number of such inequivalent representations. This paper introduces fork-connectivity, a …

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A Short Proof Of Non-Gf(5)-Representability Of Matroids, Jim Geelen, James Oxley, Dirk Vertigan, Geoff Whittle Jan 2004

A Short Proof Of Non-Gf(5)-Representability Of Matroids, Jim Geelen, James Oxley, Dirk Vertigan, Geoff Whittle

Faculty Publications

Tutte proved that a matroid is binary if and only if it does not contain a U2,4-minor. This provides a short proof for non-GF(2)-representability in that we can verify that a given minor is isomorphic to U2,4 in just a few rank evaluations. Using excluded-minor characterizations, short proofs can also be given of non-representablity over GF(3) and over GF(4). For GF(5), it is not even known whether the set of excluded minors is finite. Nevertheless, we show here that if a matroid is not representable over GF(5), then this can be verified by a short proof. Here a "short proof" …

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Homogeneous Multivariate Polynomials With The Half-Plane Property, Young Bin Choe, James G. Oxley, Alan D. Sokal, David G. Wagner Jan 2004

Homogeneous Multivariate Polynomials With The Half-Plane Property, Young Bin Choe, James G. Oxley, Alan D. Sokal, David G. Wagner

Faculty Publications

A polynomial P in n complex variables is said to have the "half-plane property" (or Hurwitz property) if it is nonvanishing whenever all the variables lie in the open right half-plane. Such polynomials arise in combinatorics, reliability theory, electrical circuit theory and statistical mechanics. A particularly important case is when the polynomial is homogeneous and multiaffine: then it is the (weighted) generating polynomial of an r-uniform set system. We prove that the support (set of nonzero coefficients) of a homogeneous multiaffine polynomial with the half-plane property is necessarily the set of bases of a matroid. Conversely, we ask: For which …

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Bounded-From-Below Solutions Of The Hamilton-Jacobi Equation For Optimal Control Problems With Exit Times: Vanishing Lagrangians, Eikonal Equations, And Shape-From-Shading, Michael Malisoff Jan 2004

Bounded-From-Below Solutions Of The Hamilton-Jacobi Equation For Optimal Control Problems With Exit Times: Vanishing Lagrangians, Eikonal Equations, And Shape-From-Shading, Michael Malisoff

Faculty Publications

We study the Hamilton-Jacobi equation for undiscounted exit time control problems with general nonnegative Lagrangians using the dynamic programming approach. We prove theorems characterizing the value function as the unique bounded-from-below viscosity solution of the Hamilton-Jacobi equation that is null on the target. The result applies to problems with the property that all trajectories satisfying a certain integral condition must stay in a bounded set. We allow problems for which the Lagrangian is not uniformly bounded below by positive constants, in which the hypotheses of the known uniqueness results for Hamilton-Jacobi equations are not satisfied. We apply our theorems to …

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Front Matter Jan 2004

Front Matter

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

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Crusoe The Isolato Daniel Defoe Wrestles With Solitude, Irene B. Beesemyer Jan 2004

Crusoe The Isolato Daniel Defoe Wrestles With Solitude, Irene B. Beesemyer

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

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Condillac's Modernization Of Rationalist Language Theory Evidence, Propositions, And A Newtonian Linguistics, R. C. Coski Jan 2004

Condillac's Modernization Of Rationalist Language Theory Evidence, Propositions, And A Newtonian Linguistics, R. C. Coski

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

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Building The Perfect Silence The Use Of Renaissance Architecture In Margaret Cavendish's Bell In Campo, Miranda Wilson Jan 2004

Building The Perfect Silence The Use Of Renaissance Architecture In Margaret Cavendish's Bell In Campo, Miranda Wilson

1650-1850: Ideas, Aesthetics, and Inquiries in the Early Modern Era

No abstract provided.

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Comment On "Quantum Measurement And Decoherence", D. Gobert, J. Von Delft, V. Ambegaokar, R. F. O'Connell, G. W. Ford Jan 2004

Comment On "Quantum Measurement And Decoherence", D. Gobert, J. Von Delft, V. Ambegaokar, R. F. O'Connell, G. W. Ford

Faculty Publications

No abstract provided.

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Canonical Quantum Gravity And Consistent Discretizations, Rodolfo Gambini, Jorge Pullin Jan 2004

Canonical Quantum Gravity And Consistent Discretizations, Rodolfo Gambini, Jorge Pullin

Faculty Publications

This paper covers some developments in canonical quantum gravity that occurred since ICGC-2000, emphasizing the recently introduced consistent discretizations of general relativity.

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An Existence Theorem For Neutral Variational Problems Of Bolza, Norma L. Ortiz, Peter R. Wolenski Jan 2004

An Existence Theorem For Neutral Variational Problems Of Bolza, Norma L. Ortiz, Peter R. Wolenski

Faculty Publications

This note proves an existence theorem for a generalized Bolza-type problem that has time delays in both the state and velocity variables. The assumptions are stated in terms of a modification of the classical Hamiltonian, and extend ideas of Rockafellar to the delay case. © 2003 Elsevier Inc. All rights reserved.

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Content Analysis Of The Leading General Academic Databases, Kelly D. Blessinger, Maureen Olle-Lajoie Jan 2004

Content Analysis Of The Leading General Academic Databases, Kelly D. Blessinger, Maureen Olle-Lajoie

Faculty Publications

Title lists from the three leading general academic databases were compared to evaluate journal content. Some of the elements that were analyzed include subject coverage, the quality of titles provided, accessibility issues, and trends over time for these databases. While database title lists are now readily available on the Internet for comparison, as our article illustrates, these lists need further evaluation for proper assessment.

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An Evaluation Of Reference Evapotranspiration Models In Louisiana, Royce Landon Fontenot Jan 2004

An Evaluation Of Reference Evapotranspiration Models In Louisiana, Royce Landon Fontenot

LSU Master's Theses

Daily and monthly output from seven evapotranspiration models (FAO-24 Radiation, FAO-24 Blaney-Criddle, Hargreaves-Samani, Priestly-Taylor, Makkink, and Turc) have been tested against reference evapotranspiration data computed by the FAO-56 Penman-Monteith model to assess the accuracy of each model in estimating grass-reference evapotranspiration in Louisiana. Models were compared at eight stations of the Louisiana Agriclimate Information System using data from December 2002 to November 2003. Comparisons were also made using three composite regions: statewide, inland, and coastal. A pan evaporation to reference evapotranspiration model (FAO-24 Pan Evaporation) was also tested against daily grass reference evapotranspiration from the FAO-56 Penman-Monteith model using data …

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Evaluation Of A Desktop Computed Radiography System For Imrt Dosimetry, Ines-Ana Jurkovic Jan 2004

Evaluation Of A Desktop Computed Radiography System For Imrt Dosimetry, Ines-Ana Jurkovic

LSU Master's Theses

Different techniques have been developed and used to evaluate dose distribution calculation accuracy and dose delivery reproducibility as a part of patient-specific IMRT QA – e.q. film dosimetry, ionization chambers, and diode arrays. To verify that the calculated dose distribution is delivered accurately during treatment, film dosimetry is usually used. The accuracy and reproducibility of film optical density as an indicator of dose is influenced by several variables, including the chemical processing and scanning conditions. This study investigates the possibility to use a desktop computed radiography (CR) system for patient-specific intensity modulated radiation therapy (IMRT) quality assurance (QA). A study …

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Comparative Analysis Between Different Flood Assessment Technologies In Hazus-Mh, Jennifer Carol Meyer Jan 2004

Comparative Analysis Between Different Flood Assessment Technologies In Hazus-Mh, Jennifer Carol Meyer

LSU Master's Theses

Natural disasters devastate the United States through both economic loss and loss of life. The world wide economic damage that results from natural disasters has more than tripled in the last thirty years. Of these natural disasters, floods are the most chronic and costly disasters, comprising an average $5 billion dollars of damage each year. FEMA has released a new software program called HAZUS-MH, which attempts to capture economic losses caused by flooding before losses occur and predict losses from real-time events. This estimate is accomplished through the coupling of flood hazard modeling with local data. FEMA’s goal is that …

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Teaching Elementary Students With Attention-Deficit/Hyperactivity Disorder To Recruit Teacher Attention: Effects On Teacher Praise, On-Task Behavior, And Academic Work, Angie Lynn Pellegrin Jan 2004

Teaching Elementary Students With Attention-Deficit/Hyperactivity Disorder To Recruit Teacher Attention: Effects On Teacher Praise, On-Task Behavior, And Academic Work, Angie Lynn Pellegrin

LSU Master's Theses

Recruitment training and self-monitoring skills have proven to be effective methods of decreasing off-task behavior and increasing work productivity and positive teacher-student interactions. Teaching students to recruit teacher attention provides an opportunity for the teacher to praise the child or to offer instructional feedback. However, research on this topic has not examined its utilization and effectiveness in children diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD). Using a multiple baseline across subjects design, the present study will examine the effectiveness of training students with ADHD to monitor task progress and recruit teacher attention.

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Numerical Solution Of Fractional Advection-Dispersion Equation, Zhi Qiang Deng, Vijay P. Singh, Lars Bengtsson Jan 2004

Numerical Solution Of Fractional Advection-Dispersion Equation, Zhi Qiang Deng, Vijay P. Singh, Lars Bengtsson

Faculty Publications

Numerical schemes and stability criteria are developed for solution of the one-dimensional fractional advection-dispersion equation (FRADE) derived by revising Fick's first law. Employing 74 sets of dye test data measured on natural streams, it is found that the fractional order F of the partial differential operator acting on the dispersion term varies around the most frequently occurring value of F=1.65 in the range of 1.4 to 2.0. Two series expansions are proposed for approximation of the limit definitions of fractional derivatives. On this ground, two three-term finite-difference schemes - "1.3 Backward Scheme"having the first-order accuracy and "F.3 Central Scheme"possessing the …

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Study On The Termiticidal Components Of Juniperus Virginiana, Chamaecyparis Nootkatensis And Chamaecyparis Lawsoniana, Yaojian Liu Jan 2004

Study On The Termiticidal Components Of Juniperus Virginiana, Chamaecyparis Nootkatensis And Chamaecyparis Lawsoniana, Yaojian Liu

LSU Master's Theses

Termites cause serious damage to wood and wood products. In recent years, increasing attention has been paid to extractives from naturally decay resistant trees. In this study, we compared the termiticidal and antifungal effects of extractives from Alaska yellow cedar (AYC), Port-Orford cedar (POC), and Eastern red cedar (ERC). Pentane and Hexane-Acetone extractives from YC and POC, and pentane extractives from ERC were most favorable in terms of termite protection among the extractives we got. Weight loss of strips treated with 5000 ppm pentane extractives from Eastern red cedar, was significantly lower than those treated with solutions of pentane extractive …

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Kinetic Analysis Of Kluyveromyces Marxianus Yeast Strain, Erika Guimaraes Madeira Reeves Jan 2004

Kinetic Analysis Of Kluyveromyces Marxianus Yeast Strain, Erika Guimaraes Madeira Reeves

LSU Master's Theses

This research investigated the growth kinetic parameters (Ks and µmax) of the Kluyveromyces marxianus yeast strain for a batch process under aerobic and anaerobic conditions at 45oC using the Two-Liter Bioflo® 2000 Fermentors and the Orbital Shaker Bed with 250mL flasks (New Brunswick Scientific). This yeast strain was grown in twelve different glucose media concentrations (Anderson et al. 1986), ranging from 200 mg/L to 80,000 mg/L. Several analytical techniques were used, such as COD measurement to determine soluble and total substrate concentrations, TSS and OD measurements to determine biomass formation, HPLC measurements to determine carbohydrate concentrations, and GC measurements to …

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Extreme Precipitation Events In East Baton Rouge Parish: An Areal Rainfall Frequency/Magnitude Analysis, Michelle Marie Russo Jan 2004

Extreme Precipitation Events In East Baton Rouge Parish: An Areal Rainfall Frequency/Magnitude Analysis, Michelle Marie Russo

LSU Master's Theses

Severe rainfall events are one of the most frequent weather hazards in the United States. These events are particularly problematic for the southeastern United States because of its subtropical climate. For these reasons, and because of the recent urban growth in the parish, East Baton Rouge Parish officials are concerned whether the current stormwater drainage system can keep pace with development. As a result, this project evaluated the rainfall frequency/magnitude for parish-wide extreme events and their synoptic forcing mechanisms. To this end, this research mapped parish-wide storms and compared three interpolation techniques. It also compared two methods of areal summation …

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Complexity And Nekton Use Of Marsh Edge Habitats In Barataria Bay, Louisiana, Timothy W. Birdsong Jan 2004

Complexity And Nekton Use Of Marsh Edge Habitats In Barataria Bay, Louisiana, Timothy W. Birdsong

LSU Master's Theses

This study examined the effects of intrahabitat variability on marsh edge use by fishes and decapod crustaceans. The objectives were to (1) identify quantitative measures of habitat complexity that describe the structural design of marsh edge habitats, and (2) examine differences in nekton use between cut-bank and gently sloping marsh edge habitats. The study was conducted in Barataria Bay, Louisiana at 75, 10-m marsh edge study sites. Monthly seining was conducted in fall 2003 and spring 2004 and measures of habitat complexity were recorded at each sample location. Indices of tidal inundation and site exposure to wind and wave action …

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Experimental Validation Of A Smart-Bias Active Magnetic Bearing Controller, Shailesh Pradhananga Jan 2004

Experimental Validation Of A Smart-Bias Active Magnetic Bearing Controller, Shailesh Pradhananga

LSU Master's Theses

Active magnetic bearings (AMBs) are being increasingly employed in the aerospace industry in a variety of devices including compressors, turbines, pumps, and flywheels. One application of great interest to future space missions is the Integrated Power and Attitude Control System (IPACS). The IPACS consists of an arrangement of flywheels that integrates the energy storage and attitude control functions into a single system; thereby, reducing the spacecraft mass, volume, launching cost, and maintenance. Like any energy storage system, flywheels need to be operated with low power losses. AMBs are ideally suited for flywheels because they eliminate mechanical losses (friction). Nevertheless, AMBs …

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Transport And Deposition Of Fluid Mud Event Layers Along The Western Louisiana Inner Shelf, Kristina Anne Rotondo Jan 2004

Transport And Deposition Of Fluid Mud Event Layers Along The Western Louisiana Inner Shelf, Kristina Anne Rotondo

LSU Master's Theses

The western Louisiana inner shelf along the Chenier Plain coast has experienced fluid mud deposition in response to increased fine sediment supplied by the Atchafalaya River since ~1950’s. The goal of this project is to assess the characteristics comprising the sedimentary strata and stratigraphic architecture that result from mud deposition on the inner shelf. Recent time-series cores collected from the inner shelf along the Chenier plain coast show the region is subject to transient fluid mud deposition, leading to high long-term accumulation rates. Sediment cores were collected in May 2001, March and May 2002 from the inner shelf landward of …

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Survivable Multicasting In Wdm Optical Networks, Sateesh Chandra Shekhar Jan 2004

Survivable Multicasting In Wdm Optical Networks, Sateesh Chandra Shekhar

LSU Master's Theses

Opportunities abound in the global content delivery service market and it is here that multicasting is proving to be a powerful feature. In WDM networks, optical splitting is widely used to achieve multicasting. It removes the complications of optical-electronic-optical conversions [1]. Several multicasting algorithms have been proposed in the literature for building light trees. As the amount of fiber deployment increases in networks, the risk of losing large volumes of data traffic due to a fiber span cut or due to node failure also increases. In this thesis we propose heuristic schemes to make the primary multicast trees resilient to …

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