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High Capacity Digital Beam Steering Technology, Daniel James Hebert Jan 2013

High Capacity Digital Beam Steering Technology, Daniel James Hebert

LSU Doctoral Dissertations

A novel method is described in detail for steering light in many directions without moving mechanical parts. The method involves a combination of liquid crystal cells and polarizing beam splitters. The polarization at each beam splitter is controlled by applying a signal to its corresponding liquid crystal cell. A study of light steering techniques is described for efficient beam placement, in a line and plane. These techniques permit accurate, non-mechanical, beam steering limited by the response time of the liquid crystal cells. A theoretical limit to the number of discrete directions is described and closely approached for a one dimensional …


Technology Argument Frames : Examining The Impact Of Argumentation On The Development Of A Health Information Exchange Initiative, David Murithi Murungi Jan 2013

Technology Argument Frames : Examining The Impact Of Argumentation On The Development Of A Health Information Exchange Initiative, David Murithi Murungi

LSU Doctoral Dissertations

This dissertation applies the Technology Frames of Reference (TFR) theoretical lens to examine the implementation of a health information exchange (HIE) initiative in southeast USA. It extends the TFR lens by developing Toulminian argument maps to depict frame structure and employing the argument theories of Toulmin, Habermas and Perelman Olbrechts-Tyteca to help analyze the role that argumentation plays in the emergence and development of the technology frames that characterized this HIE endeavor. The argument maps developed in this dissertation helped to assess the level of argumentation within frames and to compare argumentation across frame domains. The argument maps were also …


Geometric Modeling And Optimization Over Regular Domains For Graphics And Visual Computing, Shenghua Wan Jan 2013

Geometric Modeling And Optimization Over Regular Domains For Graphics And Visual Computing, Shenghua Wan

LSU Doctoral Dissertations

The effective construction of parametric representation of complicated geometric objects can facilitate many design, analysis, and simulation tasks in Computer-Aided Design (CAD), Computer-Aided Manufacturing (CAM), and Computer-Aided Engineering (CAE). Given a 3D shape, the procedure of finding such a parametric representation upon a canonical domain is called geometric parameterization. Regular geometric regions, such as polycubes and spheres, are desirable domains for parameterization. Parametric representations defined upon regular geometric domains have many desirable mathematical properties and can facilitate or simplify various surface/solid modeling and processing computation. This dissertation studies the construction of parameterization on regular geometric domains and explores their applications …


Group 3 Late Embryogenesis Abundant Proteins From Embryos Of Artemia Francisana : Molecular Characteristics, Expression And Function, Leaf Chandra Boswell Jan 2013

Group 3 Late Embryogenesis Abundant Proteins From Embryos Of Artemia Francisana : Molecular Characteristics, Expression And Function, Leaf Chandra Boswell

LSU Doctoral Dissertations

Late Embryogenesis Abundant (LEA) proteins are highly hydrophilic, intrinsically disordered proteins whose expression has been correlated with desiccation tolerance in anhydrobiotic organisms. Embryos of the brine shrimp, A. franciscana, contain high titers of group 3 LEA proteins during desiccation-tolerant stages such as diapause and pre-emergence development. Here I report the sequencing of three novel variants of AfrLEA3m mRNA (Afrlea3m_47, Afrlea3m_43 and Afrlea3m_29), whose deduced protein sequences are are predicted to localize to the mitochondrion. These mRNAs are very similar to Afrlea3m, but each has a stretch of sequence that is absent in at least one of the others. In addition …


Evolutionary And Ecological Dynamics Of Rapid Radiation Of Pocket Gophers (Thomomy's) In Mexico, Verity Lynn Mathis Jan 2013

Evolutionary And Ecological Dynamics Of Rapid Radiation Of Pocket Gophers (Thomomy's) In Mexico, Verity Lynn Mathis

LSU Doctoral Dissertations

Understanding biodiversity is one of the driving foundations of evolutionary biology and researchers use a myriad of tools to uncover and understand the processes contributing to it. The evolutionary and ecological dynamics in a group of smooth-toothed pocket gophers, the Thomomys umbrinus species complex, is studied for this dissertation. This complex is distributed from south-central Arizona and southwestern New Mexico south to Veracruz, Mexico. The genetic complexity of T. umbrinus was initially discovered via allozymes and karyotypes, resulting in five genetic clades: three with one diploid number of chromosomes (2n = 76; two clades distributed in the Sierra Madre Occidental …


Large Deviations For Stochastic Navier-Stokes Equations With Nonlinear Viscosities, Ming Tao Jan 2013

Large Deviations For Stochastic Navier-Stokes Equations With Nonlinear Viscosities, Ming Tao

LSU Doctoral Dissertations

In this work, a Wentzell-Freidlin type large deviation principle is established for the two-dimensional stochastic Navier-Stokes equations (SNSE's) with nonlinear viscosities. We fi_x000C_rst prove the existence and uniqueness of solutions to the two-dimensionalstochastic Navier-Stokes equations with nonlinear viscosities using the martingale problem argument and the method of monotonicity. By the results of Varadhan and Bryc, the large deviation principle (LDP) is equivalent to the Laplace-Varadhan principle (LVP) if the underlying space is Polish. Then using the stochastic control and weak convergence approach developed by Budhiraja and Dupuis, the Laplace-Varadhan principle for solutions of stochastic Navier-Stokesequations is obtained in appropriate function …


Classroom Observation, Self-Assessment Of Efficacy, And Student Perceptions Of Engagement As Predictors Of Value-Added Scores, Leslie Davis Blanchard Jan 2013

Classroom Observation, Self-Assessment Of Efficacy, And Student Perceptions Of Engagement As Predictors Of Value-Added Scores, Leslie Davis Blanchard

LSU Doctoral Dissertations

The purpose of this study was to determine which has the strongest correlation to student achievement as measured by value-added test scores: Principal Observations, Teachers Self-Efficacy Ratings, or Student Perceptions of Teacher Effectiveness. 68 teachers from a K-12 public school in the southeast region of the United States agreed to participate in the study. The Teachers’ Sense of Efficacy Scale (TSES) was utilized to measure the teachers in terms of their own reports of self efficacy. The School Improvement Model (SIM) of Iowa State University instruments were used to measure the students’ perceptions of teacher effectiveness. The Teacher Advancement Program …


Resolving Pronominal Anaphora Using Commonsense Knowledge, Seyedeh Leili Javadpour Jan 2013

Resolving Pronominal Anaphora Using Commonsense Knowledge, Seyedeh Leili Javadpour

LSU Doctoral Dissertations

Coreference resolution is the task of resolving all expressions in a text that refer to the same entity. Such expressions are often used in writing and speech as shortcuts to avoid repetition. The most frequent form of coreference is the anaphor. To resolve anaphora not only grammatical and syntactical strategies are required, but also semantic approaches should be taken into consideration. This dissertation presents a framework for automatically resolving pronominal anaphora by integrating recent findings from the field of linguistics with new semantic features. Commonsense knowledge is the routine knowledge people have of the everyday world. Because such knowledge is …


Time Of Day Preferences And Resource Allocation, Alicia Marie Briganti Jan 2013

Time Of Day Preferences And Resource Allocation, Alicia Marie Briganti

LSU Doctoral Dissertations

Previous studies have shown that circadian rhythms can have a significant impact on cognitive task performance (Bodenhausen, 1990; May, Hasher, & Stoltzfus, 1993), and that performance is better during participants’ optimal time of day for explicit memory tasks and for tasks where inhibition of responses is required. Researchers have concluded that deficits during one’s non-optimal time of day are due to inefficient inhibition (e.g., May & Hasher, 1998). However, previous studies have not sufficiently addressed possible changes in resource allocation, or the amount of resources that are allocated to the primary task versus the amount of resources used to actively …


Topology And Shape Optimization Of Hydrodynamically–Lubricated Bearings For Enhanced Load-Carrying Capacity, Mohammad Fesanghary Jan 2013

Topology And Shape Optimization Of Hydrodynamically–Lubricated Bearings For Enhanced Load-Carrying Capacity, Mohammad Fesanghary

LSU Doctoral Dissertations

Bearings are basic and essential components of nearly all machinery. They must be designed to work under different loads, speeds, and environments. Of all the performance parameters, load-carrying capacity (LCC) is often the most crucial design constraint. The objective of this research is to investigate different design methodologies that significantly improve the LCC of liquid-lubricated bearings. This goal can be achieved by either altering the surface texture or the bearing geometrical configuration. The methodology used here is based on mathematical topological/shape optimization algorithms. These methods can effectively improve the design performance while avoiding time-consuming trial-and-error design techniques. The first category …


Alexis De Tocqueville’S Political Science Of Revolutions; Theory And Application, Michal Maciej Kuz Jan 2013

Alexis De Tocqueville’S Political Science Of Revolutions; Theory And Application, Michal Maciej Kuz

LSU Doctoral Dissertations

This dissertation examines the theory of revolutions presented in the main writing of Alexis de Tocqueville and its importance in the field of political theory as well as its possible application in the field of comparative politics. Scholars specializing in the study of the writings of Alexis de Tocqueville have for many years debated on whether the works of this author offer a comprehensive political theory of regimes and political change. This work supports the idea that in all his major writings de Tocqueville works within the same theoretical framework and develops his own typology of modern regimes. At the …


Modeling, Numerical Analysis, And Predictions For The Detonation Of Multi-Component Energetic Solids, Michael Wayne Crochet Jan 2013

Modeling, Numerical Analysis, And Predictions For The Detonation Of Multi-Component Energetic Solids, Michael Wayne Crochet

LSU Doctoral Dissertations

Metal powders are often used as an additive to conventional high explosives to enhance the post-detonation blast wave. Piston-impact simulations are commonly utilized to predict performance metrics such as detonation speed and strength, as well as assessing the impact and shock sensitivity of these materials. The system response is strongly influenced by the initial particle size distribution and material composition. Multiphase continuum models have been routinely applied at the macroscale to characterize the detonation of solid high explosives over engineering length scales. Current models lack a description of the physically permissible constitutive relations for mass transfer due to general chemical …


Geodatabase-Assisted Storm Surge Modeling, Sait Ahmet Binselam Jan 2013

Geodatabase-Assisted Storm Surge Modeling, Sait Ahmet Binselam

LSU Doctoral Dissertations

Tropical cyclone-generated storm surge frequently causes catastrophic damage in communities along the Gulf of Mexico. The prediction of landfalling or hypothetical storm surge magnitudes in U.S. Gulf Coast regions remains problematic, in part, because of the dearth of historic event parameter data, including accurate records of storm surge magnitude (elevation) at locations along the coast from hurricanes. While detailed historical records exist that describe hurricane tracks, these data have rarely been correlated with the resulting storm surge, limiting our ability to make statistical inferences, which are needed to fully understand the vulnerability of the U.S. Gulf Coast to hurricane-induced storm …


An Alu Element-Based Model Of Human Genome Instability, George Wyndham Cook, Jr. Jan 2013

An Alu Element-Based Model Of Human Genome Instability, George Wyndham Cook, Jr.

LSU Doctoral Dissertations

The human genome is strewn with repetitive sequence. An early estimate derived from the draft human genome sequence placed this repetitive content at ~45%. More detailed recent analyses have advanced the idea that the human repetitive and repeat derived contribution to the genome may be closer to 66-69%. The most commonly repeated sequence in the human genome is the Alu element. Alus make up 10.6 percent of all human DNA and have expanded to over one million copies in the human genome reproducing through a copy and paste mechanism. New Alu germline insertions are estimated to occur at a rate …


Study On The Performance Of Tcp Over 10gbps High Speed Networks, Cheng Cui Jan 2013

Study On The Performance Of Tcp Over 10gbps High Speed Networks, Cheng Cui

LSU Doctoral Dissertations

Internet traffic is expected to grow phenomenally over the next five to ten years. To cope with such large traffic volumes, high-speed networks are expected to scale to capacities of terabits-per-second and beyond. Increasing the role of optics for packet forwarding and transmission inside the high-speed networks seems to be the most promising way to accomplish this capacity scaling. Unfortunately, unlike electronic memory, it remains a formidable challenge to build even a few dozen packets of integrated all-optical buffers. On the other hand, many high-speed networks depend on the TCP/IP protocol for reliability which is typically implemented in software and …


Detection Of Microorganisms Using Maldi And Ion Mobility Mass Spectrometry, Juaneka Monet Hayes Jan 2013

Detection Of Microorganisms Using Maldi And Ion Mobility Mass Spectrometry, Juaneka Monet Hayes

LSU Doctoral Dissertations

Matrix-assisted laser ablation desorption ionization MALDI and ion mobility (IM) MALDI mass spectrometry (MS) were used for the detection and identification of microorganisms. MALDI MS is an analytical tool that separates ions by their mass-to-charge ratio (m/z) and is routinely used for bioanalysis because of its sensitivity, selectivity, general applicability, and tolerance to impurities. Ion mobility is a gas phase technique that separates ions based on their charge and collision cross-section. In this research, MALDI-TOF MS and MALDI-IM-TOF MS analysis were conducted in parallel to assess the effectiveness of MALDI-IM-TOF MS for microorganism identification. Whole cell bacteria Escherichia coli strain …


Complexity-Driven Properties Of The Intermetallic Compounds Gd₁₁₇Co₅₆Sn₁₁₂ And Ln₃₀Ru₄Sn₃₁ (Ln = Gd And Tb), Devin Charles Schmitt Jan 2013

Complexity-Driven Properties Of The Intermetallic Compounds Gd₁₁₇Co₅₆Sn₁₁₂ And Ln₃₀Ru₄Sn₃₁ (Ln = Gd And Tb), Devin Charles Schmitt

LSU Doctoral Dissertations

Understanding the relationships between the structure of materials and their properties in extended solid systems is a necessity when intuitively designing functional materials. One of the most fundamental properties of a material is its ability to transport heat, which is linked to the lattice complexity of the material. Here, the single crystalline materials Gd117Co56Sn112 and Tb30Ru4Sn31 are grown to study the pronounced effect of a complexity-driven reduction of lattice thermal conductivity. The transport and magnetic properties of Gd117Co56Sn112 and Ln30Ru4Sn31 (Ln = Gd and Tb) are also presented and related to other systems. Tb30Ru4Sn31 is found to be a large …


Poultry Litter Ash As A Phosphorus Source For Greenhouse Crop Production, Daniel Evan Wells Jan 2013

Poultry Litter Ash As A Phosphorus Source For Greenhouse Crop Production, Daniel Evan Wells

LSU Doctoral Dissertations

Phosphorus (P) is an essential nutrient for all life forms, including plants, but is a limited agricultural resource whose future availability is in question. Therefore, identification of alternative forms of P fertilizers is important. Poultry litter ash (PLA), a byproduct of bioenergy production, contains high concentrations of P comparable to conventional fertilizers. Forms of P contained in PLA have been characterized as having low water solubility. Nutrient losses during containerized plant production are high due to excessive inputs of water and nutrients and low nutrient sorption capacities of common horticultural substrate components. Environmental concerns over reduced water quality intensify this …


Academic Self-Monitoring In College Students With Attention-Deficit/Hyperactivity Disorder, Mindy C. Scheithauer Jan 2013

Academic Self-Monitoring In College Students With Attention-Deficit/Hyperactivity Disorder, Mindy C. Scheithauer

LSU Doctoral Dissertations

Self-monitoring is an intervention that can result in behavior change by having individuals observe and record their own behavior. Self-monitoring has received empirical support in changing Attention-Deficit/Hyperactivity Disorder (ADHD) related behaviors in children, but there is scarce research regarding self-monitoring with adults with ADHD. The current study implemented a self-monitoring intervention aimed at improving academic behavior and medication adherence in college students with ADHD. The self-monitoring intervention included study skills training, goal-setting, identification of individualized self-monitoring behavior, and follow-up meetings to discuss progress. The participants were asked to monitor their behavior on a daily basis using an electronic system. Compared …


A History Of Peer-Led Team Learning, 1990-2012, A.E. Dreyfuss Jan 2013

A History Of Peer-Led Team Learning, 1990-2012, A.E. Dreyfuss

Publications and Research

From Workshop Chemistry in 1991 at the City College of New York, CUNY, to implementation in other disciplines and development of Peer-Led Team Learning and its Six Critical Components, this paper reviews the contributions of faculty at a variety of higher education institutions to the dissemination and growth of PLTL as a successful model of student engagement with the position of the student Peer Leader.


Metal-Based Microchannel Heat Exchangers : Manufacturing And Heat Transfer Testing, Bin Lu Jan 2013

Metal-Based Microchannel Heat Exchangers : Manufacturing And Heat Transfer Testing, Bin Lu

LSU Doctoral Dissertations

This dissertation focuses on improving the functionality of metal-based microchannel heat exchangers (MHEs), as well as pushing this technology toward real-world applications. Design optimization was carried out on MHEs for performance maximization. Double-layered microchannel layout was experimentally studied, and a significant reduction on liquid flow pressure drop penalty was achieved. Other than water, another commonly-used coolant, ethylene glycol, was applied to MHEs, and flow and heat transfer characteristics were quantified. Transient Liquid Phase (TLP) bonding was used for joining Cu structures. For further understanding of the MHE heat transfer, a detailed examination was carried out on the TLP bonding interface …


The Effect Of Real-Time Pitch Tracking And Correction On High School Instrumentalists' Tuning Accuracy, Kathryn Elizabeth Strickland Jan 2013

The Effect Of Real-Time Pitch Tracking And Correction On High School Instrumentalists' Tuning Accuracy, Kathryn Elizabeth Strickland

LSU Doctoral Dissertations

The main purpose of this study was to determine the effectiveness of pitch tracking and correction (auto-tuning) on the intonation performed by high school clarinet (n = 30) and trumpet (n = 30) players with at least three years of experience in the large ensemble setting. Participants (N = 60) were assigned to one of three treatment groups, each differentiated by means of intonation evaluation. An aural group (n = 20) used Real Time Pitch Tracking and Correction (RTPTC) software; a visual group (n = 20) used an electronic tuner; and a control group (n = 20) “played in-tune to …


Two Histories, One Future : Louisiana Sugar Planters, Their Slaves, And The Anglo-Creole Schism, 1815-1865, Nathan Buman Jan 2013

Two Histories, One Future : Louisiana Sugar Planters, Their Slaves, And The Anglo-Creole Schism, 1815-1865, Nathan Buman

LSU Doctoral Dissertations

During the five decades between the War of 1812 and the end of the Civil War, southern Louisianans developed a society unlike any other region. The vibrant traditional image of moonlight and magnolias, the notion that King Cotton dominated the South’s economy as Anglo-Saxon masters lorded over their enslaves African-American workers still dominates the image of the American South. This image of a monolithic South, however, does not give a clear indication of the many sub-regional distinctions that both challenged and rewarded the inhabitants of those areas and provides exciting ways to understand slaveholding society culturally. Louisiana’s slaveholding class consisted …


Fast And Reliable Detection Of Incumbent Users In Cognitive Radios, Mahdi Orooji Jan 2013

Fast And Reliable Detection Of Incumbent Users In Cognitive Radios, Mahdi Orooji

LSU Doctoral Dissertations

Fast and reliable Spectrum Sensing (SS) plays a crucial role in the cognitive radio (CR) technology in order to prevent unwanted interference to the primary users (PU) and to reliably and quickly detect the white spaces in the spectrum for opportunistic access by the secondary users (SU). Spectrum Sensing must often be performed in the absence of information such as PU signaling scheme, noise level and channel fading coefficients. While these parameters can be estimated in the SU, estimation errors significantly deteriorates the performance of SS techniques. In this thesis, we introduce and evaluate the performance of two novel blind …


Psychological Behavior Analysis Using Advanced Signal Processing Techniques For Fmri Data, Charisma Dionne Edwards Jan 2013

Psychological Behavior Analysis Using Advanced Signal Processing Techniques For Fmri Data, Charisma Dionne Edwards

LSU Doctoral Dissertations

Psychological analysis related to voluntary reciprocal trust games were obtained using functional magnetic resonance imaging (fMRI) hyperscanning for 44 pairs of strangers throughout 36 trust games (TG) and 16 control games (CG). Hidden Markov models (HMMs) are proposed to train and classify the fMRI data acquired from these brain regions and extract the essential features of the initial decision of the first player to trust or not trust the second player. These results are evaluated using the different versions of the multifold cross-validation technique and compared to other speech data and other advanced signal processing techniques including linear classification, support …


Method And Apparatus For Adaptive Scatter Correction, Xin Liu, J. Hsieh, X. Wu Jan 2013

Method And Apparatus For Adaptive Scatter Correction, Xin Liu, J. Hsieh, X. Wu

Nuclear Engineering and Radiation Science Faculty Research & Creative Works

A CT system includes a rotatable gantry having an opening to receive an object to be scanned, an x-ray source configured to project an x-ray beam toward the object having a primary intensity, a detector configured to detect high frequency electromagnetic energy passing through the object and output imaging data, and a data acquisition system (DAS) connected to the detector and configured to receive the imaging data. The system also includes a computer programmed to obtain image projection data of the object from the DAS, correct the projection data using a scatter function that is based at least on a …


Translating Arthur : The Historia Regum Brittanniae Of Geoffrey Of Monmouth And Roman De Brut Of Wace, George Gregory Molchan Jan 2013

Translating Arthur : The Historia Regum Brittanniae Of Geoffrey Of Monmouth And Roman De Brut Of Wace, George Gregory Molchan

LSU Doctoral Dissertations

This dissertation primarily focuses on re-presentations of the foreign others in the twelfth-century chronicles Historia regum Britanniae of Geoffrey of Monmouth and Roman de Brut of Wace of the Isle of Jersey. Geoffrey and Wace, I argue, deploy a number of strategies in their narratives regarding the Matter of Britain that mainly though not wholly work to reinforce hegemonic versions of history through dehumanizing and demonizing the others that inhabit their narratives. The strategies that Geoffrey and Wace deploy towards the inhabitants of their narratives, I contend, operate within a framework that both celebrates and defends the Normans’ pretensions to …


Cyclic Block Copolypeptoids : Synthesis, Self-Assembly And Macroscopic Properties, Chang-Uk Lee Jan 2013

Cyclic Block Copolypeptoids : Synthesis, Self-Assembly And Macroscopic Properties, Chang-Uk Lee

LSU Doctoral Dissertations

This dissertation presents the first experimental efforts for synthesizing a new class of peptidomimetic polymers, cyclic block copolypeptoids, studying their self-assembly in dilute solution, and examining their macroscopic properties. Cyclic poly(N-methyl-glycine)-b-poly(N-decyl-glycine) (PNMG-b-PNDG) diblock copolymers were synthesized via sequential, N-heterocyclic carbene (NHC)-mediated ring-opening polymerization of NCA monomers with controlled chain length and compositions. Cryo-TEM shows that PNMG105-b-PNDG10 copolymers in methanol (1 mg/mL) form spherical micelles that organize to form cylindrical micelles over time. The formation of cylindrical micelles is attributed to the crystallization of PNDG chains, as revealed by SAED and microDSC analyses. Cyclic PNMG100-b-PNDG10 copolymers form thermo-reversible, free-standing gels at …


Predictors Of Practice Approaches And Activitives Of Louisiana School Social Workers : Toward A Model Of Practice, Laura Richard Jan 2013

Predictors Of Practice Approaches And Activitives Of Louisiana School Social Workers : Toward A Model Of Practice, Laura Richard

LSU Doctoral Dissertations

ABSTRACT The purpose of the current exploratory-descriptive study was to examine the role of school social workers in Louisiana (N = 378) and the relationship of roles in different school settings and with different caseload sizes. The information gained was used to develop a conceptual model of practice and a job description for Louisiana school social workers. In addition, predictors of the types of practice approaches and practice activities used in the different school employment settings and with different caseload sizes were also included. The school social workers were employed in school districts in Louisiana and completed an online or …


Volatile Congregations : Crisis Sensemaking In A Southern Baptist Church, Brandon Douglas Bannon Jan 2013

Volatile Congregations : Crisis Sensemaking In A Southern Baptist Church, Brandon Douglas Bannon

LSU Doctoral Dissertations

The primary purpose of this study was to test the assertion that Sensemaking Theory is an appropriate lens to understand church crisis by highlighting the role of communication as a central aspect of the sensemaking process. In addition, through the application of Sensemaking Theory, the secondary goal was to assist congregations as they try to avoid the negative consequences of church splits. The analysis utilized in the current study was specifically selected to develop a history of participant interpretation within a church in order to determine how members made sense of the crisis. To that end, this study followed the …