Digital Commons Network^™

Reversibility Checking For Markov Chains, P. H. Brill, Chi Ho Cheung, Myron Hlynka, Q. Jiang

Communications on Stochastic Analysis

No abstract provided.

Particulate Matter Containing Environmentally Persistent Free Radicals Induces Ahrdependent Cytokine And Reactive Oxygen Species Production In Human Bronchial Epithelial Cells, Ashlyn C. Harmon, Valeria Y. Hebert, Stephania A. Cormier, Balamurugan Subramanian, James R. Reed, Wayne L. Backes, Tammy R. Dugas

Faculty Publications

© 2018 Harmon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Particulate matter (PM) is emitted during the combustion of fuels and wastes. PM exposure exacerbates pulmonary diseases, and the mechanism may involve oxidative stress. At lower combustion temperatures such as occurs in the cool zone of a flame, aromatic compounds chemisorb to the surface of metal-oxide-containing PM, resulting in the formation of surface-stabilized environmentally persistent free radicals (EPFR). Prior studies showed …

Sediment Accumulation And Bioturbation An A Tropical-Carbonate Mangrove Forest On A Pacific Atoll: Ouvéa, New Caledonia, Ryder Myers

Honors Capstones

No abstract provided.

A Stochastic Integral By A Near-Martingale, Shinya Hibino, Hui-Hsiung Kuo, Kimiaki Saitô

Communications on Stochastic Analysis

No abstract provided.

Paley–Wiener Theorem For Line Bundles Over Compact Symmetric Spaces And New Estimates For The Heckman–Opdam Hypergeometric Functions, Vivian M. Ho, Gestur Ólafsson

Faculty Publications

Paley–Wiener type theorems describe the image of a given space of functions, often compactly supported functions, under an integral transform, usually a Fourier transform on a group or homogeneous space. In this article we proved a Paley–Wiener theorem for smooth sections f of homogeneous line bundles on a compact Riemannian symmetric space U/K. It characterizes f with small support in terms of holomorphic extendability and exponential growth of their χ-spherical Fourier transforms, where χ is a character of K. An important tool in our proof is a generalization of Opdam's estimate for the hypergeometric functions associated to multiplicity functions that …

Towards A Splitter Theorem For Internally 4-Connected Binary Matroids Vi, Carolyn Chun, James Oxley

Faculty Publications

Let M be a 3-connected binary matroid; M is called internally 4-connected if one side of every 3-separation is a triangle or a triad, and M is internally 4-connected if one side of every 3-separation is a triangle, a triad, or a 4-element fan. Assume M is internally 4-connected and that neither M nor its dual is a cubic Möbius or planar ladder or a certain coextension thereof. Let N be an internally 4-connected proper minor of M. Our aim is to show that M has a proper internally 4-connected minor with an N-minor that can be obtained from M …

Multigrid Methods For H(Div) In Three Dimensions With Nonoverlapping Domain Decomposition Smoothers, Susanne C. Brenner, Duk Soon Oh

Faculty Publications

We design and analyze V-cycle multigrid methods for an H(div) problem discretized by the lowest-order Raviart–Thomas hexahedral element. The smoothers in the multigrid methods involve nonoverlapping domain decomposition preconditioners that are based on substructuring. We prove uniform convergence of the V-cycle methods on bounded convex hexahedral domains (rectangular boxes). Numerical experiments that support the theory are also presented.

Nonlinear Equations With Gradient Natural Growth And Distributional Data, With Applications To A Schrödinger Type Equation, Karthik Adimurthi, Nguyen Cong Phuc

Faculty Publications

We obtain necessary and sufficient conditions with sharp constants on the distribution (Formula presented.) for the existence of a globally finite energy solution to the quasi-linear equation with a gradient source term of natural growth of the form (Formula presented.) in a bounded open set (Formula presented.). Here (Formula presented.), (Formula presented.), is the standard (Formula presented.) -Laplacian operator defined by (Formula presented.). The class of solutions that we are interested in consists of functions (Formula presented.) such that (Formula presented.) for some (Formula presented.) and the inequality (Formula presented.) holds for all (Formula presented.) with some constant (Formula presented.). …

Bridge Inspecting With Unmanned Aerial Vehicles R&D, Paul Darby, Vijaya Gopu

Publications

The project achieves through research including literature, on site interviews, and experimentation: 1) a recommendation for a UAV-based system to practically assist in routine bridge inspection work in the State of Louisiana, 2) the identification and description of advantages, disadvantages, and limitations in the use of UAVs for routing bridge inspection work in Louisiana, and 3) provided recommendations for future work. The Yuneec H520 aircraft and its E90 camera are recommended, as is the need for a boat to be included as part of the system. The recommended system has advantages in reaching portions of the bridge that are difficult …

Design, Simulation, And Construction Of An Ieee 14-Bus Power System, John Albert Boudreaux

LSU Master's Theses

Today’s bulk power system is massive, complex, and very dynamic. The U.S. power grid spans from coast to coast and even as far reaching as Canada. With the addition of new technologies such as renewable energies and power electronics to aid in power conversion and control, the power system grows more complex by the day. The most common approach of analyzing power system stability is through computer modeling and simulation. Due to the vast size and inaccessibility of transmission systems, real time testing can prove difficult. The motivation of this project was to design, simulate, and construct an IEEE 14 …

Qualitative Dynamics And Inflationary Attractors In Loop Cosmology, Bao Fei Li, Parampreet Singh, Anzhong Wang

Faculty Publications

Qualitative dynamics of three different loop quantizations of spatially flat isotropic and homogeneous models is studied using an effective spacetime description of the underlying quantum geometry. These include the standard loop quantum cosmology (LQC), its recently revived modification (referred to as mLQC-I), and another related modification of LQC (mLQC-II) of which the dynamics is studied in detail for the first time. Various features of LQC, including quantum bounce and preinflationary dynamics, are found to be shared with the mLQC-I and mLQC-II models. We study universal properties of dynamics for chaotic inflation, fractional monodromy inflation, Starobinsky potential, nonminimal Higgs inflation, and …

Selling, General, And Administrative Cost Stickiness And Gdp Predictions, Russell Barber

LSU Doctoral Dissertations

This study examines whether selling, general, and administrative (SG&A) cost stickiness is informative in predicting GDP growth and in explaining GDP forecast errors. Prior research has examined how accounting earnings growth is informative in predicting GDP. However, up to this point there has been a lack of research examining how accounting cost behavior is informative in predicting GDP growth. Managers make SG&A cost decisions based on projections of future demand, so the main hypothesis of this study is that cost stickiness has an informational role in predicting GDP growth and in explaining GDP forecast errors. The empirical findings of this …

The 'Happiest' Corner Of London: Bethnal Green, 1550-1945, Audrey Lynne Gray

LSU Doctoral Dissertations

How is a cultural identity created, defined, and used? In this study, I have traced Bethnal Green’s cultural identity in the period between 1550 and1945. It was a cultural identity defined by poverty, but also by hope; residents were poor but scrappy, able to make do with the worst of circumstances. That cultural identity defined the area to outsiders; it was also embraced by the residents. Following the area’s path from an idyllic and genteel area to an overcrowded slum, I have traced the experience of poverty, and the development and impact of poverty relief, from the perspective of both …

Techniques Of Energy-Efficient Vlsi Chip Design For High-Performance Computing, Zhou Zhao

LSU Doctoral Dissertations

How to implement quality computing with the limited power budget is the key factor to move very large scale integration (VLSI) chip design forward. This work introduces various techniques of low power VLSI design used for state of art computing. From the viewpoint of power supply, conventional in-chip voltage regulators based on analog blocks bring the large overhead of both power and area to computational chips. Motivated by this, a digital based switchable pin method to dynamically regulate power at low circuit cost has been proposed to make computing to be executed with a stable voltage supply. For one of …

Accelerated Motion And The Self-Force In Schwarzschild Spacetime, Anna Heffernan, Adrian C. Ottewill, Niels Warburton, Barry Wardell, Peter Diener

Faculty Publications

We provide expansions of the Detweiler-Whiting singular field for a particle with a scalar field moving along arbitrary, planar accelerated trajectories in Schwarzschild spacetime. We transcribe these results into mode-sum regularization parameters, computing previously unknown terms that increase the convergence rate of the mode-sum. We test our results by computing the self-force along a variety of accelerated trajectories. For non-uniformly accelerated circular orbits we present results from a new 1+1D discontinuous Galerkin time-domain code which employs an effective source. We also present results for uniformly accelerated circular orbits and accelerated bound eccentric orbits computed within a frequency-domain treatment. Our regularization …

Negative Energy Blowup Results For The Focusing Hartree Hierarchy Via Identities Of Virial And Localized Virial Type, Aynur Bulut

Faculty Publications

We establish virial and localized virial identities for solutions to the Hartree hierarchy, an infinite system of partial differential equations which arises in mathematical modeling of many body quantum systems. As an application, we use arguments originally developed in the study of the nonlinear Schrödinger equation (see work of Zakharov, Glassey, and Ogawa–Tsutsumi) to show that certain classes of negative energy solutions must blowup in finite time. The most delicate case of this analysis is the proof of negative energy blowup without the assumption of finite variance; in this case, we make use of the localized virial estimates, combined with …

Sustaining Stem Initiatives: The Challenge Of A Worthy Investment, Melissa B. Crawford, Tyrslai M. Williams, Zakiya Wilson-Kennedy, Linda Hooper-Bui, Megan Stone, Isiah M. Warner

Faculty Publications

No abstract provided.

Effective Maxwell’S Equations For Perfectly Conducting Split Ring Resonators, Robert Lipton, Ben Schweizer

Faculty Publications

We analyze the time harmonic Maxwell’s equations in a geometry containing perfectly conducting split rings. We derive the homogenization limit in which the typical size η of the rings tends to zero. The split rings act as resonators and the assembly can act, effectively, as a magnetically active material. The frequency dependent effective permeability of the medium can be large and/or negative.

A Notion Of Minor-Based Matroid Connectivity, Zachary Gershkoff, James Oxley

Faculty Publications

For a matroid N, a matroid M is N-connected if every two elements of M are in an N-minor together. Thus a matroid is connected if and only if it is U1,2-connected. This paper proves that U1,2 is the only connected matroid N such that if M is N-connected with |E(M)|>|E(N)|, then M\e or M/e is N-connected for all elements e. Moreover, we show that U1,2 and M(W2) are the only matroids N such that, whenever a matroid has an N-minor using {e,f} and an N-minor using {f,g}, it also has an N-minor using {e,g}. Finally, we show that …

Horizontal Dispersion Of Buoyant Materials In The Ocean Surface Boundary Layer, Jun Hong Liang, Xiaoliang Wan, Kenneth A. Rose, Peter P. Sullivan, James C. Mcwilliams

Faculty Publications

The horizontal dispersion of materials with a constant rising speed under the exclusive influence of ocean surface boundary layer (OSBL) flows is investigated using both three-dimensional turbulence-resolving Lagrangian particle trajectories and the classical theory of dispersion in bounded shear currents generalized for buoyant materials. Dispersion in the OSBL is caused by the vertical shear of mean horizontal currents and by the turbulent velocity fluctuations. It reaches a diffusive regime when the equilibrium vertical material distribution is established. Diffusivity from the classical shear dispersion theory agrees reasonably well with that diagnosed using three-dimensional particle trajectories. For weakly buoyant materials that can …

The Mayer And Minimum Time Problems With Stratified State Constraints, C. Hermosilla, P. R. Wolenski, H. Zidani

Faculty Publications

This paper studies optimal control problems with state constraints by imposing structural assumptions on the constraint domain coupled with a tangential restriction with the dynamics. These assumptions replace pointing or controllability assumptions that are common in the literature, and provide a framework under which feasible boundary trajectories can be analyzed directly. The value functions associated with the state constrained Mayer and minimal time problems are characterized as solutions to a pair of Hamilton-Jacobi inequalities with appropriate boundary conditions. The novel feature of these inequalities lies in the choice of the Hamiltonian.

Framework Design For Weight-Average Molecular Weight Control In Semi-Batch Polymerization, S. D. Salas, N. Ghadipasha, W. Zhu, T. Mcafee, T. Zekoski, W. F. Reed, J. A. Romagnoli

Faculty Publications

A framework that embraces a state-of-the-art sensor, multi-objective dynamic optimization, nonlinear state estimation and control, is designed and implemented to achieve target weight-average molecular weight trajectories. The Automatic Continuous Online Monitoring of Polymerization reactions (ACOMP) is combined for the first time with a nonlinear state observer for full polymer characterization and signal processing. A hybrid variation of the discrete-time extended Kalman filter (h-DEKF) is formulated based on an auto-tuning procedure that uses a stochastic global optimization technique. A number of optimal policies are generated and experimentally tested. Results are provided through investigations into the free-radical aqueous polymerization of acrylamide using …

Impacts Of Updated Design Rainfall Values On Louisiana Infrastructure, Mario Durbic

LSU Master's Theses

The Louisiana Department of Transportation and Development (LADOTD) has a Hydraulics Manual which sets forth drainage design standards and codes for projects. The Manual contains maximum annual 24-hour rainfall maps and Intensity-Duration-Frequency (IDF) curves for the return periods of 2, 5, 10, 25, 50, and 100 years. The Manual divides Louisiana into three regions and specifies that all of the cities within a given region should use the same estimated rainfall intensities and rainfall depths. NOAA Atlas 14, the Precipitation-Frequency Atlas of United States, contains the latest rainfall data and statistics for much of the United States and provides the …

Development Of Long-Term Aging Factor For Asphalt Mixtures’ Cracking Resistance, Yucheng Shi

LSU Master's Theses

To characterize the cracking resistance of asphalt mixtures, semi-circular bend (SCB) test has been developed and subsequently accepted as a routine test in mixture design in Louisiana. However, SCB test requires specimens to be aged for five days in laboratory, which makes it not implementable in quality control (QC)/quality assurance (QA).

The primary project objective was to develop an aging factor to transfer the unaged SCB Jc to the aged SCB Jc. Specific objectives were to: (1) investigate the effect of laboratory aging on asphalt mixtures’ cracking resistance and asphalt binders’ rheological and chemical properties, (2) develop an aging …

Investigation Of Flow Mechanisms In Gas-Assisted Gravity Drainage Process, Iskandar Dzulkarnain

LSU Doctoral Dissertations

In this study we investigate displacement mechanism for oil recovered using Gas- Assisted Gravity Drainage (GAGD) method. For a typical oil recovery under gravity drainage, the recovery profile can be characterized by an initial bulk flow which occurs rapidly and a later film flow that extends for a longer duration. It is the latter period where film spreading, the ability of oil to spread above water in the presence of gas, is identified as the displacement mechanism responsible for recovering the remaining oil in gravity drainage process. Literature survey indicates that mathematical models for gravity drainage do not account for …

High-Dimensional Isotope Relationships, Yuyang He

LSU Doctoral Dissertations

High-dimensional isotope relationships describes the relationships of two or more element or position-specific (PS) elements in the same molecule or ion. It provides us more powerful tools to study reaction mechanisms and dynamics. Chapter 1 is about dual or multiple stable isotope relationship on δ-δ (or δ'-δ') space. While temporal data sampled from a closed-system can be treated by a Rayleigh Distillation Model (RDM), spatial data should be treated by a Reaction-Transport Model (RTM). Here we compare the results of a closed-system RDM to a RTM for systems with diffusional mass transfer by simulating the trajectories on nitrate's δ'^{18 …}

Investigation Of Flow Mechanisms In Gas-Assisted Gravity Drainage Process, Iskandar Dzulkarnain

LSU Doctoral Dissertations

In this study we investigate displacement mechanism for oil recovered using Gas- Assisted Gravity Drainage (GAGD) method. For a typical oil recovery under gravity drainage, the recovery profile can be characterized by an initial bulk flow which occurs rapidly and a later film flow that extends for a longer duration. It is the latter period where film spreading, the ability of oil to spread above water in the presence of gas, is identified as the displacement mechanism responsible for recovering the remaining oil in gravity drainage process. Literature survey indicates that mathematical models for gravity drainage do not account for …

A Study On Reduction Of Harmonic Distortion Caused By Ac Arc Furnaces, Venkata Mani Gadiraju

LSU Master's Theses

In AC arc furnaces, arc ignition is stabilized by inductors which are connected across its supply lines. They cause power factor degradation in the system. When furnaces are modelled as linear RL load, the arc nonlinearity reduces the impact of this degradation to a significant extent. Furnace Power factor is improved by the DC voltage on the arc. In this research study, power factor of AC furnaces is estimated on the assumption that DC voltage on the arc is constant and furnace operates in steady state. Primary objective of this research was to determine the power factor of the furnace …

Development Of Self-Healing Mechanisms For Asphalt Pavements, Max Abelardo Aguirre Deras

LSU Doctoral Dissertations

Self-healing mechanisms, such as microcapsules or hollow-fibers, filled with an asphalt rejuvenator present an emerging technology that would enhance an asphalt mixture’s resistance to cracking damage caused by vehicular and environmental loading. The objectives of this study were to: (a) Evaluate the effects of asphalt rejuvenators on hot-mix asphalt mixtures in order to test its effects on the fundamental engineering properties of the mixtures at high and intermediate temperatures; (b) Develop a synthesis procedure for production of microcapsules and hollow-fibers containing an asphalt rejuvenator; (c) Evaluate the self-healing efficiency of double-walled microcapsules and hollow-fibers filled with an asphalt rejuvenator, through …

Development Strategies For A Fractured, Heavy Oil Reservoir - Results From Numerical Simulations, German Albertovich Abzaletdinov

LSU Master's Theses

This research is focused on studying reservoir “N” in the Yarega heavy oilfield (YHOF) for development strategies and production optimization. YHOF is a naturally fractured heavy oil field where only very recently SAGD technology has been introduced. The motivation for this research is derived from the fact that SAGD employed in this field has so far resulted in early steam breakthrough leading to producer abandonment and new drilling, thus increasing costs. This study explores numerically different static and dynamic reservoir characterization models (single porosity versus dual porosity systems), and subsequent pressure-production history matched reservoir simulation for understanding heat and mass …