Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Louisiana State University

2020

Discipline
Keyword
Publication
Publication Type
File Type

Articles 1 - 30 of 1279

Full-Text Articles in Entire DC Network

Distributed Load Testing By Modeling And Simulating User Behavior, Chester Ira Parrott Dec 2020

Distributed Load Testing By Modeling And Simulating User Behavior, Chester Ira Parrott

LSU Doctoral Dissertations

Modern human-machine systems such as microservices rely upon agile engineering practices which require changes to be tested and released more frequently than classically engineered systems. A critical step in the testing of such systems is the generation of realistic workloads or load testing. Generated workload emulates the expected behaviors of users and machines within a system under test in order to find potentially unknown failure states. Typical testing tools rely on static testing artifacts to generate realistic workload conditions. Such artifacts can be cumbersome and costly to maintain; however, even model-based alternatives can prevent adaptation to changes in a system …


Experiential Statistics: A Case Study In Favor Of Using Project-Based Learning To Advance Preliminary Statistics Content Knowledge In The Algebra I And Geometry Classroom, Trey Michael Earle Dec 2020

Experiential Statistics: A Case Study In Favor Of Using Project-Based Learning To Advance Preliminary Statistics Content Knowledge In The Algebra I And Geometry Classroom, Trey Michael Earle

LSU Doctoral Dissertations

Preparing secondary students for college entrance requirements and the expectations of the job market, a market which is actively seeking the employees who are most qualified to take on jobs that require data analysis skills, is becoming increasingly important. Federal, state, and local education administrators and personnel must rewrite many of the general education curricula to incorporate data organization, collection, manipulation, application, and analysis in order to better prepare students for the expectations of college entrance and an ever-changing employment market. From a purely pedagogical standpoint, while traditional educational structure has been commonplace for decades in the United States, projects …


Salt Marsh Elevation Limit Determined After Subsidence From Hydrologic Change And Hydrocarbon Extraction, R. Eugene Turner, Yu Mo Dec 2020

Salt Marsh Elevation Limit Determined After Subsidence From Hydrologic Change And Hydrocarbon Extraction, R. Eugene Turner, Yu Mo

Faculty Publications

Levee construction aboveground and hydrocarbon removal from belowground in coastal wetlands can create hydrologic changes that increase plant stress through flooding. But the significance of the subsidence they cause individually or in combination is contested. This study untangled them to demonstrate elevational limits of salt marshes by studying dredged and natural waterways in two salt marshes in Louisiana, USA. The areas had a homogenous plant cover before drilling for oil and gas extraction peaked in the 1960s, and now are a mixed network of natural waterways and dredged canals used to drill wells with an average drill date of 1965.8 …


Primordial Scalar Power Spectrum From The Hybrid Approach In Loop Cosmologies, Bao Fei Li, Javier Olmedo, Parampreet Singh, Anzhong Wang Dec 2020

Primordial Scalar Power Spectrum From The Hybrid Approach In Loop Cosmologies, Bao Fei Li, Javier Olmedo, Parampreet Singh, Anzhong Wang

Faculty Publications

We compare the primordial scalar power spectra in the loop cosmological models using the effective dynamics of the hybrid approach to cosmological perturbations in which the background is loop quantized, but the perturbations are Fock quantized. The three loop cosmological models under consideration are the standard loop quantum cosmology (LQC), the modified LQC-I (mLQC-I) and the modified LQC-II (mLQC-II) in the spatially flat Friedmann-Lemaître-Robertson-Walker universe with a Starobinsky potential. These models arise from different regularizations of the classical Hamiltonian constraint in the symmetry reduced spacetimes and aim to capture certain features of quantization in loop quantum gravity. When applying the …


Magnetic Order And Fluctuations In The Quasi-Two-Dimensional Planar Magnet Sr(Co1-Xnix)2as2, Yaofeng Xie, Yu Li, Zhiping Yin, Rui Zhang, Weiyi Wang, Matthew B. Stone, Huibo Cao, D. L. Abernathy, Leland Harriger, David P. Young, J. F. Ditusa, Pengcheng Dai Dec 2020

Magnetic Order And Fluctuations In The Quasi-Two-Dimensional Planar Magnet Sr(Co1-Xnix)2as2, Yaofeng Xie, Yu Li, Zhiping Yin, Rui Zhang, Weiyi Wang, Matthew B. Stone, Huibo Cao, D. L. Abernathy, Leland Harriger, David P. Young, J. F. Ditusa, Pengcheng Dai

Faculty Publications

We use neutron scattering to investigate spin excitations in Sr(Co1-xNix)2As2, which has a c-axis incommensurate helical structure of the two-dimensional (2D) in-plane ferromagnetic (FM) ordered layers for 0.013=x=0.25. By comparing the wave vector and energy dependent spin excitations in helical ordered Sr(Co0.9Ni0.1)2As2 and paramagnetic SrCo2As2, we find that Ni doping, while increasing lattice disorder in Sr(Co1-xNix)2As2, enhances quasi-2D FM spin fluctuations. However, our band structure calculations within the combined density functional theory and dynamic mean field theory (DFT+DMFT) failed to generate a correct incommensurate wave vector for the observed helical order from nested Fermi surfaces. Since transport measurements reveal increased …


Bottom-Up Approach To Assess The Molecular Structure Of Aqueous Poly(N‑Isopropylacrylamide) At Room Temperature Via Infrared Spectroscopy, Habtom B. Gobeze, Jianbo Ma, Fedra M. Leonik, Daniel G. Kuroda Dec 2020

Bottom-Up Approach To Assess The Molecular Structure Of Aqueous Poly(N‑Isopropylacrylamide) At Room Temperature Via Infrared Spectroscopy, Habtom B. Gobeze, Jianbo Ma, Fedra M. Leonik, Daniel G. Kuroda

Faculty Publications

© 2020 American Chemical Society The structure of poly(N-isopropylacrylamide) (PNIPAM) in solution is still an unresolved topic. Here, the PNIPAM structure in water was investigated using a bottom-up approach, involving the monomer, dimer, and trimer, and a combination of infrared (IR) spectroscopies as well as molecular dynamics simulations. The experiments show that the monomer and oligomers exhibit a broad and asymmetric amide I band with two underlying transitions, while PNIPAM presents the same major transitions and a minor one. Analysis of the 2D IR spectra and theoretical modeling of the amide I band indicates that the two transitions of the …


Efficient Low-Cost Procedure For Microextraction Of Estrogen From Environmental Water Using Magnetic Ionic Liquids, Paula Berton, Noureen Siraj, Susmita Das, Sergio De Rooy, Rodolfo G. Wuilloud, Isiah M. Warner Dec 2020

Efficient Low-Cost Procedure For Microextraction Of Estrogen From Environmental Water Using Magnetic Ionic Liquids, Paula Berton, Noureen Siraj, Susmita Das, Sergio De Rooy, Rodolfo G. Wuilloud, Isiah M. Warner

Faculty Publications

In this study, three magnetic ionic liquids (MILs) were investigated for extraction of four estrogens, i.e., estrone (E1), estradiol (E2), estriol (E3), and ethinylestradiol (EE2), from environmental water. The cation trihexyl(tetradecyl)phosphonium ([P66614]+), selected to confer hydrophobicity to the resulting MIL, was combined with tetrachloroferrate(III), ferricyanide, and dysprosium thiocyanate to yield ([P66614][FeCl4]), ([P66614]3[Fe(CN)6]), and ([P66614]5[Dy(SCN)8]), respectively. After evaluation of various strategies to develop a liquid-liquid microextraction technique based on synthesized MILs, we placed the MILs onto a magnetic stir bar and used them as extracting solvents. After extraction, the MIL-enriched phase was dissolved in methanol and injected into an HPLC-UV for …


Towards A Reduced Phase Space Quantization In Loop Quantum Cosmology With An Inflationary Potential, Kristina Giesel, Bao Fei Li, Parampreet Singh Dec 2020

Towards A Reduced Phase Space Quantization In Loop Quantum Cosmology With An Inflationary Potential, Kristina Giesel, Bao Fei Li, Parampreet Singh

Faculty Publications

We explore a reduced phase space quantization of loop quantum cosmology (LQC) for a spatially flat Friedmann-Lemaître-Robertson-Walker (FLRW) universe filled with reference fields and an inflaton field in a Starobinsky inflationary potential. We consider three separate cases in which the reference fields are taken to be the Gaussian dust, the Brown-Kuchař dust, and massless Klein-Gordon scalar reference fields respectively. This is a "two-fluid"model in which reference fields act as global clocks providing a physical time in an inflationary spacetime, and allow bypassing various technical hurdles in conventional quantum cosmological models. The reduced phase space is obtained in terms of the …


Identification Of Blda As A Major Regulator Of Virulence In The Sweetpotato Soil Rot Pathogen Streptomyces Ipomoeae And Characterization Of Distinct Clostridium Sweetpotato Soft Rot Isolates, Kuei-Ting Yang Dec 2020

Identification Of Blda As A Major Regulator Of Virulence In The Sweetpotato Soil Rot Pathogen Streptomyces Ipomoeae And Characterization Of Distinct Clostridium Sweetpotato Soft Rot Isolates, Kuei-Ting Yang

LSU Doctoral Dissertations

Streptomyces ipomoeae is the causative agent of Streptomyces soil rot on sweetpotato, a disease characterized by extensive necrosis of both adventitious and storage roots. While Streptomyces potato scab pathogens produce a phytotoxin (thaxtomin A), which is induced in the presence of cellobiose and suberin, S. ipomoeae produces a less-modified, phytotoxin (thaxtomin C), whose inducer has not been identified. To investigate transcriptional regulation of thaxtomin C production, we inserted a promoter involved in thaxtomin C synthesis upstream of the gusA reporter in an S. ipomoeae strain. Reporter gene expression was significantly upregulated in the presence of size-fractionated sweetpotato extract (SPE). The …


Perceived Vulnerability To Covid-19 Infection From Event Attendance: Results From Louisiana, Usa, Two Weeks Preceding The National Emergency Declaration, Ran Li, Bingcheng Yang, Jerrod Penn, Bailey Houghtaling, Juan Chen, Witoon Prinyawiwatkul, Brian E. Roe, Danyi Qi Dec 2020

Perceived Vulnerability To Covid-19 Infection From Event Attendance: Results From Louisiana, Usa, Two Weeks Preceding The National Emergency Declaration, Ran Li, Bingcheng Yang, Jerrod Penn, Bailey Houghtaling, Juan Chen, Witoon Prinyawiwatkul, Brian E. Roe, Danyi Qi

Faculty Publications

Background: Individual perceptions of personal and national threats posed by COVID-19 shaped initial response to the pandemic. The aim of this study was to investigate the changes in residents' awareness about COVID-19 and to characterize those who were more aware and responsive during the early stages of the pandemic in Louisiana.

Methods: In response to the mounting threat of COVID-19, we added questions to an ongoing food preference study held at Louisiana State University from March 3rd through March 12th, 2020. We asked how likely it was that the spread of the coronavirus will cause a national public health crisis …


Direct Measurement Of The Cosmic-Ray Carbon And Oxygen Spectra From 10 Gev/ N To 2.2 Tev/ N With The Calorimetric Electron Telescope On The International Space Station, O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, M. Bongi, P. Brogi, A. Bruno, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, K. Ebisawa, H. Fuke, S. Gonzi, T. G. Guzik, T. Hams, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka Dec 2020

Direct Measurement Of The Cosmic-Ray Carbon And Oxygen Spectra From 10 Gev/ N To 2.2 Tev/ N With The Calorimetric Electron Telescope On The International Space Station, O. Adriani, Y. Akaike, K. Asano, Y. Asaoka, M. G. Bagliesi, E. Berti, G. Bigongiari, W. R. Binns, M. Bongi, P. Brogi, A. Bruno, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, K. Ebisawa, H. Fuke, S. Gonzi, T. G. Guzik, T. Hams, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose, C. Kato, N. Kawanaka

Faculty Publications

In this paper, we present the measurement of the energy spectra of carbon and oxygen in cosmic rays based on observations with the Calorimetric Electron Telescope on the International Space Station from October 2015 to October 2019. Analysis, including the detailed assessment of systematic uncertainties, and results are reported. The energy spectra are measured in kinetic energy per nucleon from 10 GeV/n to 2.2 TeV/n with an all-calorimetric instrument with a total thickness corresponding to 1.3 nuclear interaction length. The observed carbon and oxygen fluxes show a spectral index change of ∼0.15 around 200 GeV/n established with a significance >3σ. …


Registration Of The Transition Radiation With Gaas Detector: Data/Mc Comparison, J. Alozy, N. Belyaev, B. L. Bergmann, T. R.V. Billoud, P. Broulim, P. Burian, M. Campbell, G. Chelkov, M. Cherry, F. Dachs, S. Doronin, K. Filippov, P. Fusco, F. Gargano, E. H.M. Heijne, S. Konovalov, X. Llopart Cudie, F. Loparco, M. N. Mazziotta, L. Meduna, H. Pernegger, D. Ponomarenko, S. Pospisil, D. Rastorguev, C. Rembser, A. Romaniouk, A. A. Savchenko, E. J. Schioppa, S. Smirnov, Y. Smirnov, P. Smolyanskiy, P. Spinelli, M. Strikhanov Dec 2020

Registration Of The Transition Radiation With Gaas Detector: Data/Mc Comparison, J. Alozy, N. Belyaev, B. L. Bergmann, T. R.V. Billoud, P. Broulim, P. Burian, M. Campbell, G. Chelkov, M. Cherry, F. Dachs, S. Doronin, K. Filippov, P. Fusco, F. Gargano, E. H.M. Heijne, S. Konovalov, X. Llopart Cudie, F. Loparco, M. N. Mazziotta, L. Meduna, H. Pernegger, D. Ponomarenko, S. Pospisil, D. Rastorguev, C. Rembser, A. Romaniouk, A. A. Savchenko, E. J. Schioppa, S. Smirnov, Y. Smirnov, P. Smolyanskiy, P. Spinelli, M. Strikhanov

Faculty Publications

New developments of pixel detectors based on GaAs sensors offer effective registration of the transition radiation (TR) X-rays and perform simultaneous measurements of their energies and emission angles. This unique feature opens new possibilities for particle identification on the basis of maximum available information about generated TR photons. Results of studies of TR energy-Angular distributions using a 500 |j.m thick GaAs sensor attached to a Timepix3 chip are presented. Measurements, analysis techniques and a comparison with Monte Carlo (MC) simulations are described and discussed.


A Concept Of The Transition Radiation Detector For A Hadron Separation In A Forward Direction Of The Lhc Experiments, N. Belyaev, M. L. Cherry, S. A. Doronin, K. Filippov, P. Fusco, F. Gargano, S. Konovalov, F. Loparco, M. N. Mazziotta, A. Mufazalova, S. Nechaeva, D. Ponomarenko, C. Rembser, A. Romaniouk, A. A. Savchenko, E. Shulga, S. Smirnov, Yu Smirnov, P. Spinelli, L. Sultanaliyeva, P. Teterin, V. Tikhomirov, K. Vorobev, K. Zhukov Dec 2020

A Concept Of The Transition Radiation Detector For A Hadron Separation In A Forward Direction Of The Lhc Experiments, N. Belyaev, M. L. Cherry, S. A. Doronin, K. Filippov, P. Fusco, F. Gargano, S. Konovalov, F. Loparco, M. N. Mazziotta, A. Mufazalova, S. Nechaeva, D. Ponomarenko, C. Rembser, A. Romaniouk, A. A. Savchenko, E. Shulga, S. Smirnov, Yu Smirnov, P. Spinelli, L. Sultanaliyeva, P. Teterin, V. Tikhomirov, K. Vorobev, K. Zhukov

Faculty Publications

Studying of hadron production in forward direction at the LHC energy has a great interest both for understanding of the fundamental QCD processes and also in applied areas such as the description of ultra-high energy cosmic particle interactions. The energies of secondary hadrons in such studies almost reach the maximum energy available at the LHC of ∼6 TeV, which corresponds to a Lorentz γ-factor up to 104 and above. The only effective technique able to identify particles in this range is based on the transition radiation detectors (TRD). Prototypes of such kind of detector were built and tested at the …


A Nonstandard Proof Of De Finetti’S Theorem For Bernoulli Random Variables, Irfan Alam Dec 2020

A Nonstandard Proof Of De Finetti’S Theorem For Bernoulli Random Variables, Irfan Alam

Journal of Stochastic Analysis

No abstract provided.


Interface Engineering Of Materials For Energy And Biological Applications, Ardalan Chaichi Dec 2020

Interface Engineering Of Materials For Energy And Biological Applications, Ardalan Chaichi

LSU Doctoral Dissertations

Interface interactions are generally classified into solid-liquid, solid-gas, solid-vacuum, liquid-gas, light-matter and electron-matter categories. Surface morphological studies as well as surface chemical reactions can be studied in various types of complex systems thanks to technological advances in materials characterization methods. By employing interface engineering in different applications, it is possible to control electrical, chemical, mechanical, optical and biological properties of materials. Accordingly, we have applied interface engineering in three different areas of energy materials, biomaterials and surface imaging. As a result, firstly, we have introduced a high intensity light flash-based method on engineered substrates for delamination of reduced graphene oxide …


The Boundedness Of General Alternative Singular Integrals With Respect To The Gaussian Measure, Eduard Navas, Ebner Pineda, Wilfredo O. Urbina Dec 2020

The Boundedness Of General Alternative Singular Integrals With Respect To The Gaussian Measure, Eduard Navas, Ebner Pineda, Wilfredo O. Urbina

Journal of Stochastic Analysis

No abstract provided.


Optomechanical Entanglement At Room Temperature: A Simulation Study With Realistic Conditions, Kahlil Y. Dixon, Lior Cohen, Narayan Bhusal, Christopher Wipf, Jonathan P. Dowling, Thomas Corbitt Dec 2020

Optomechanical Entanglement At Room Temperature: A Simulation Study With Realistic Conditions, Kahlil Y. Dixon, Lior Cohen, Narayan Bhusal, Christopher Wipf, Jonathan P. Dowling, Thomas Corbitt

Faculty Publications

Quantum entanglement is the key to many applications like quantum key distribution, quantum teleportation, and quantum sensing. However, reliably generating quantum entanglement in macroscopic systems has proven to be a challenge. Here, we present a detailed analysis of ponderomotive entanglement generation in a movable-end-mirror-type optomechanical cavity. These cavities utilize optomechanical interactions between the intracavity field and the end mirror to create quantum correlations. We numerically calculate an entanglement measure, the logarithmic negativity, for the quantitative assessment of the entanglement. Experimental limitations, including thermal noise and optical loss, from measurements of an existing experiment were included in the calculation, which is …


Student Perceptions Of Rules For Classroom Interaction, Hanson Paul Leblanc Iii Dec 2020

Student Perceptions Of Rules For Classroom Interaction, Hanson Paul Leblanc Iii

LSU Master's Theses

ABSTRACT

Burgoon’s expectancy violation model posits that nonverbal rule violations will be evaluated according to the perceptions toward the violator and the behavior itself. However, the violator may have perceptions regarding the appropriateness of the rule. This study measured the perceptions of high school students regarding the rules for classroom interaction. It is believed that the rules for classroom interaction are rules which have been learned through the process of socialization and enculturation into the classroom setting throughout students’ careers. These rules should be well known by all students by the time they reach tenth grade, the grade being investigated. …


Martingales And Cocycles In Quantum Probability, Kalyan B. Sinha Dec 2020

Martingales And Cocycles In Quantum Probability, Kalyan B. Sinha

Journal of Stochastic Analysis

No abstract provided.


The Evolution Of A Tropical Biodiversity Hotspot, M G. Harvey, G A. Bravo, S Claramunt, A M. Cuervo, M G. Harvey, J Battilana, G F. Seeholzer, J S. Mckay, B C. O'Meara, B C. Faircloth, S V. Edwards, J Perez-Eman, R G. Moyle, F H. Sheldon, A Aleixo, B T. Smith, R T. Chesser, L F. Silveira, J Cracraft, R T. Brumfield, E P. Derryberry Dec 2020

The Evolution Of A Tropical Biodiversity Hotspot, M G. Harvey, G A. Bravo, S Claramunt, A M. Cuervo, M G. Harvey, J Battilana, G F. Seeholzer, J S. Mckay, B C. O'Meara, B C. Faircloth, S V. Edwards, J Perez-Eman, R G. Moyle, F H. Sheldon, A Aleixo, B T. Smith, R T. Chesser, L F. Silveira, J Cracraft, R T. Brumfield, E P. Derryberry

Faculty Publications

The tropics are the source of most biodiversity yet inadequate sampling obscures answers to fundamental questions about how this diversity evolves. We leveraged samples assembled over decades of fieldwork to study diversification of the largest tropical bird radiation, the suboscine passerines. Our phylogeny, estimated using data from 2389 genomic regions in 1940 individuals of 1287 species, reveals that peak suboscine species diversity in the Neotropics is not associated with high recent speciation rates but rather with the gradual accumulation of species over time. Paradoxically, the highest speciation rates are in lineages from regions with low species diversity, which are generally …


Rényi Entropy On C*-Algebras, Farrukh Mukhamedov, Kyouhei Ohmura, Noboru Watanabe Dec 2020

Rényi Entropy On C*-Algebras, Farrukh Mukhamedov, Kyouhei Ohmura, Noboru Watanabe

Journal of Stochastic Analysis

No abstract provided.


Berry Phase Manipulation In Ultrathin Srruo3 Films, Liang Wu, Fangdi Wen, Yixing Fu, Justin H. Wilson, Xiaoran Liu, Yujun Zhang, Denis M. Vasiukov, Mikhail S. Kareev, J. H. Pixley, Jak Chakhalian Dec 2020

Berry Phase Manipulation In Ultrathin Srruo3 Films, Liang Wu, Fangdi Wen, Yixing Fu, Justin H. Wilson, Xiaoran Liu, Yujun Zhang, Denis M. Vasiukov, Mikhail S. Kareev, J. H. Pixley, Jak Chakhalian

Faculty Publications

Berry phase is a powerful concept that unravels the nontrivial role of topology in phenomena observed in chiral magnetic materials and structures. A celebrated example is the anomalous Hall effect (AHE) driven by the nonvanishing Berry phase in momentum space. As the AHE is dependent on details of the band structure near the Fermi edge, the Berry phase and AHE can be altered in thin films whose chemical potential is tunable by dimensionality and disorder. Here, we demonstrate how Berry phase in ultrathin SrRuO3 films provides a comprehensive explanation for the nontrivial Hall response which is conventionally attributed to the …


Synthesis Of Structurally Diverse Molecular Scaffolds Enabled By Protected Oxyallyl Cations, Joshua Andrew Malone Dec 2020

Synthesis Of Structurally Diverse Molecular Scaffolds Enabled By Protected Oxyallyl Cations, Joshua Andrew Malone

LSU Doctoral Dissertations

This dissertation focuses on the synthesis of diverse molecular scaffolds through the use of protected oxyallyl cation intermediates. Chapter One provides background on the generation and applications of oxyallyl and silyloxyallyl cations, while focusing on the direct nucleophilic capture of theses intermediates to generate functionalized ketones and silylenolates. Chapter Two depicts our approach to generate six-membered silyloxyallyl cations through the use of mild Brønsted acid activation. Regioselective nucleophilic capture of these intermediates successfully produced diverse a,a’-substituted silylenol ethers enabled by polar solvent and residual water.

Chapter three details strategies to generate 1,4-dicarbonyl compounds, focusing on the capture of cationic intermediates …


Entropic Signatures Of The Skyrmion Lattice Phase In Mnsi1-Xalx And Fe1-Ycoysi, C. Dhital, J. F. Ditusa Dec 2020

Entropic Signatures Of The Skyrmion Lattice Phase In Mnsi1-Xalx And Fe1-Ycoysi, C. Dhital, J. F. Ditusa

Faculty Publications

The entropic signatures of magnetic phase transitions in the skyrmion lattice host compounds MnSi0.962Al0.038 and Fe0.7Co0.3Si were investigated through low field magnetization and ac susceptibility measurements. These data indicate that the conical to skyrmion transition that occurs with the application of magnetic field in MnSi0.962Al0.038 is characterized by clear discontinuity in the magnetic entropy as expected for first order topological phase transition. These same magnetoentropic features are negligibly small in isostructural Fe0.7Co0.3Si due to the level of chemical substitution related disorder and differences in the spin dynamics (range and timescales). Despite the obvious similarities in the magnetic structures of these …


Reinforcement Learning Approach For Inspect/Correct Tasks, Hoda Nasereddin Dec 2020

Reinforcement Learning Approach For Inspect/Correct Tasks, Hoda Nasereddin

LSU Doctoral Dissertations

In this research, we focus on the application of reinforcement learning (RL) in automated agent tasks involving considerable target variability (i.e., characterized by stochastic distributions); in particular, learning of inspect/correct tasks. Examples include automated identification & correction of rivet failures in airplane maintenance procedures, and automated cleaning of surgical instruments in a hospital sterilization processing department. The location of defects and the corrective action to be taken for each varies from task episode. What needs to be learned are optimal stochastic strategies rather than optimization of any one single defect type and location. RL has been widely applied in robotics …


An Improved Foam Modeling Technique And Its Application To Petroleum Drilling And Production Practice, Yanfang Wang Dec 2020

An Improved Foam Modeling Technique And Its Application To Petroleum Drilling And Production Practice, Yanfang Wang

LSU Doctoral Dissertations

Foam is one of the most common used multiphase fluid in Underbalanced Drilling (UBD) and Managed Pressure Drilling (MPD). Because of its low density, high capacity of lifting and carrying cuttings, low cost and compatibility with formations, foam has become more superior than the conventional drilling mud when depleted reservoir pressure, severe lost circulation, or unstable borehole are encountered. In general, the success of foam applications rely on the understanding of the fundamentals of foam rheology in downhole conditions.

Foam rheology has been studied for decades. Conventional foam rheological models such as Power Law, Bingham Plastic, Herschel-Bulkley to explain foam …


R(P,Q) Analogs Of Discrete Distributions: General Formalism And Applications, Mahouton Norbert Hounkonnou, Fridolin Melong Dec 2020

R(P,Q) Analogs Of Discrete Distributions: General Formalism And Applications, Mahouton Norbert Hounkonnou, Fridolin Melong

Journal of Stochastic Analysis

No abstract provided.


The Yang-Mills Heat Equation On Three-Manifolds With Boundary, Nelia Charalambous Dec 2020

The Yang-Mills Heat Equation On Three-Manifolds With Boundary, Nelia Charalambous

Journal of Stochastic Analysis

No abstract provided.


Machine Learning Based Applications For Data Visualization, Modeling, Control, And Optimization For Chemical And Biological Systems, Yan Ma Dec 2020

Machine Learning Based Applications For Data Visualization, Modeling, Control, And Optimization For Chemical And Biological Systems, Yan Ma

LSU Doctoral Dissertations

This dissertation report covers Yan Ma’s Ph.D. research with applicational studies of machine learning in manufacturing and biological systems. The research work mainly focuses on reaction modeling, optimization, and control using a deep learning-based approaches, and the work mainly concentrates on deep reinforcement learning (DRL). Yan Ma’s research also involves with data mining with bioinformatics. Large-scale data obtained in RNA-seq is analyzed using non-linear dimensionality reduction with Principal Component Analysis (PCA), t-Distributed Stochastic Neighbor Embedding (t-SNE), and Uniform Manifold Approximation and Projection (UMAP), followed by clustering analysis using k-Means and Hierarchical Density-Based Spatial Clustering with Noise (HDBSCAN). This report focuses …


Emergence Of Quantum Theories From Classical Probability: Historical Origins, Developments, And Open Problems, Luigi Accardi, Yun-Gang Lu Dec 2020

Emergence Of Quantum Theories From Classical Probability: Historical Origins, Developments, And Open Problems, Luigi Accardi, Yun-Gang Lu

Journal of Stochastic Analysis

No abstract provided.