Bounded Backstepping Control And Robustness Analysis For Time-Varying Systems Under Converging-Input-Converging-State Conditions, Frédéric Mazenc, Michael Malisoff, Laurent Burlion, Jerome Weston

Faculty Publications

We provide new bounded backstepping results that ensure global asymptotic stability for a large class of partially linear systems with an arbitrarily large number of integrators. We use a dynamic extension that contains one artificial delay, and a converging-input-converging-state assumption. When the nonlinear subsystem is control affine, we provide sufficient conditions for our converging-input-converging-state assumption to hold. We also show input-to-state stability with respect to a large class of model uncertainties, and robustness to delays in the measurements of the state of the nonlinear subsystem. We illustrate our result in a first example that has a nondifferentiable vector field and …

Rényi Relative Entropies Of Quantum Gaussian States, Kaushik P. Seshadreesan, Ludovico Lami, Mark M. Wilde

Faculty Publications

The quantum Rényi relative entropies play a prominent role in quantum information theory, finding applications in characterizing error exponents and strong converse exponents for quantum hypothesis testing and quantum communication theory. On a different thread, quantum Gaussian states have been intensely investigated theoretically, motivated by the fact that they are more readily accessible in the laboratory than are other, more exotic quantum states. In this paper, we derive formulas for the quantum Rényi relative entropies of quantum Gaussian states. We consider both the traditional (Petz) Rényi relative entropy as well as the more recent sandwiched Rényi relative entropy, finding formulas …

What Can Mixed-Species Flock Movement Tell Us About The Value Of Amazonian Secondary Forests? Insights From Spatial Behavior, Karl Mokross, Jonathan R. Potts, Cameron L. Rutt, Philip C. Stouffer

Faculty Publications

The value of secondary forest for rain forest species remains an important question for conservation in the 21st century. Here, we describe the spatial behavior of understory mixed-species flocks in a heterogeneous landscape in central Amazonia. Understory mixed-species flocks represent a diverse, highly organized component of the rich Amazonian avifauna. We recorded movements within 26 flock home ranges in primary forest, secondary forest, interfaces between forest types, and forest fragments. We describe frequency and movement orientation in relation to forest edges, movement patterns and proportion of use between secondary and primary forest, the relation between home range sizes and vegetation …

Stabilization Of Miscible Viscous Fingering By A Step Growth Polymerization Reaction, S. Stewart, D. Marin, M. Tullier, J. Pojman, E. Meiburg, P. Bunton

Faculty Publications

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Abstract: Fingering is a hydrodynamic instability that occurs when a more mobile fluid displaces a fluid of lower mobility. When the primary source of the mobility difference is viscosity, the instability is termed viscous fingering. Viscous fingering is often, though not always, undesirable in industrial processes, particularly secondary petroleum recovery. Linear stability analysis by Hejazi et al. has indicated that the production of a non-monotonic viscosity profile can stabilize the interface. Herein, we use step-growth polymerization at the interface between two miscible monomers as a model system. In particular, a dithiol …

Throughput And Yield Improvement For A Continuous Discrete-Product Manufacturing System, Md Shahriar J. Hossain

LSU Doctoral Dissertations

A seam-welded steel pipe manufacturing process has mainly four distinct major design and/or operational problems dealing with buffer inventory, cutting tools, pipe sizing and inspection-rework facility. The general objective of this research is to optimally solve these four important problems to improve the throughput and yield of the system at a minimum cost.

The first problem of this research finds the optimal buffer capacity of steel strip coils to minimize the maintenance and downtime related costs. The total cost function for this coil feeding system is formulated as a constrained non-linear programming (NLP) problem which is solved with a search …

Virtual Element Methods On Meshes With Small Edges Or Faces, Susanne C. Brenner, Li Yeng Sung

Faculty Publications

We consider a model Poisson problem in Rd (d = 2, 3) and establish error estimates for virtual element methods on polygonal or polyhedral meshes that can contain small edges (d = 2) or small faces (d = 3). Our results extend the ones in [L. Beirão da Veiga, C. Lovadina and A. Russo, Stability analysis for the virtual element method, Math. Models Methods Appl. Sci. 27 (2017) 2557-2594] for the original two-dimensional virtual element method from [L. Beirão da Veiga, F. Brezzi, A. Cangiani, G. Manzini, L. D. Marini and A. Russo, Basic principles of virtual element methods, Math. …

Numerical Convergence Of Nonlinear Nonlocal Continuum Models To Local Elastodynamics, Prashant K. Jha, Robert Lipton

Faculty Publications

We quantify the numerical error and modeling error associated with replacing a nonlinear nonlocal bond-based peridynamic model with a local elasticity model or a linearized peridynamic model away from the fracture set. The nonlocal model treated here is characterized by a double-well potential and is a smooth version of the peridynamic model introduced in the work of Silling. The nonlinear peridynamic evolutions are shown to converge to the solution of linear elastodynamics at a rate linear with respect to the length scale ε of nonlocal interaction. This rate also holds for the convergence of solutions of the linearized peridynamic model …

Non-Local Methods In Fracture Dynamics, Eyad Said

LSU Doctoral Dissertations

We first introduce a regularized model for free fracture propagation based on non-local potentials. We work within the small deformation setting and the model is developed within a state based peridynamic formulation. At each instant of the evolution we identify the softening zone where strains lie above the strength of the material. We show that deformation discontinuities associated with flaws larger than the length scale of non-locality $\delta$ can become unstable and grow. An explicit inequality is found that shows that the volume of the softening zone goes to zero linearly with the length scale of non-local interaction. This scaling …

Broadband Measurement And Reduction Of Quantum Radiation Pressure Noise In The Audio Band, Jonathan Daniel Cripe

LSU Doctoral Dissertations

One hundred years after Albert Einstein predicted the existence of gravitational waves in his general theory of relativity, the Laser Interferometer Gravitational-Wave Observatory (LIGO) made the first direct detection of gravitational waves. Since the first detection of gravitational waves from a binary black hole merger, LIGO has gone on to detect gravitational waves from multiple binary black hole mergers, and more recently from a binary neutron star merger in collaboration with telescopes around the world. The detection of gravitational waves has opened a new window to the universe and has launched the era of gravitational wave astronomy.

With the first …

An Evaluation Of The Utility Of A Mass-Weighted Frequency Distribution Of Sediment For Modeling Aeolian Transport Rates, Raihan Jamil

LSU Master's Theses

Predictions made by aeolian transport models often do not match well with measured data. The poor predictive capability of these models remains a fundamental problem in aeolian geomorphology. This study evaluates the effectiveness of the recently proposed mass-weighted frequency distribution (Edwards and Namikas 2015) and the apparent von Kármán parameter proposed by Li et al. (2010) to improve transport rate predictions. The evaluation consists of comparisons of predicted transport rates versus a large dataset of measured field and lab transport rates collected from the literature. The transport rate predictions are made both with and without recalibration of model empirical coefficients. …

Comparative Study Of One Parameter Budyko Model Index And The Scs Curve Number, Cihad Ayberk Doner

LSU Master's Theses

This study investigates two water balance models from different levels of complexity to recognize the impacts of climate change on water resources. The main objective is to examine the capacity of future runoff calculations of a parsimonious simple water balance model compared to a more complex model under the climate change variables. The selected water balance models are the simple one-parameter Budyko-type model using the Zhang’s equation with single parameter (a) and the more complex model (HELP3) applying Soil Conservation Service (SCS) curve number method to calculate future runoff predictions. The study has a twofold focus, first on explaining the …

Heuristics For Client Assignment And Load Balancing Problems In Online Games, Shawn Michael Farlow

LSU Doctoral Dissertations

Massively multiplayer online games (MMOGs) have been very popular over the past decade. The infrastructure necessary to support a large number of players simultaneously playing these games raises interesting problems to solve. Since the computations involved in solving those problems need to be done while the game is being played, they should not be so expensive that they cause any noticeable slowdown, as this would lead to a poor player perception of the game. Many of the problems in MMOGs are NP-Hard or NP-Complete, therefore we must develop heuristics for those problems without negatively affecting the player experience as a …

Predicting Working Memory And Fluid Intelligence From Measures Of Musicality, Juan Alexander Ventura

LSU Master's Theses

The relationship between musicality and cognitive abilities has been a popular topic in the media and among researchers over the last 25 years. Research has been inconsistent on whether musicality influences performance on non-musical complex tasks, such as measures of working memory and fluid intelligence. Inconsistencies regarding results between studies have arisen partly due to differences in sample and task selection, in addition to conflicting interpretations of results. Consequently, we conducted an individual differences investigation on the prediction of working memory (tonal, verbal, and visuospatial) and fluid intelligence by measures of musicality (formal years of musicality training, musical sophistication, melodic …

Ab Initio Calculations Of The Linear And Nonlinear Susceptibilities Of N2, O2, And Air In Midinfrared Laser Pulses, Jeffrey M. Brown, Arnaud Couairon, Mette B. Gaarde

Faculty Publications

We present first-principles calculations of the linear and nonlinear susceptibilities of N2, O2, and air in the midinfrared (MIR) wavelength regime from 1-4μm. We extract the frequency-dependent susceptibilities from the full time-dependent dipole moment that is calculated using time-dependent density functional theory. We find good agreement with curves derived from experimental results for the linear susceptibility and with measurements for the nonlinear susceptibility up to 2.4μm. We also find that the susceptibilities are insensitive to the laser intensity even in the strong field regime up to 5×1013W/cm2. Our results will allow accurate calculations of the long-distance propagation of intense midinfrared …

Shape Memory Polymer Proppants, Methods Of Making Shape Memory Polymer Proppants For Application In Hydraulic Fracturing Treatments, Arash Dahi Taleghani, Amir Shojaei, Guoqiang Li

College of Engineering Patents

The present disclosure provides for shape memory proppants, methods for making shape memory proppants, and methods of using shape memory proppants, and the like. The strong expandable proppants of the present disclosure may be used in maintaining fracture openings.

The Handmaiden Of Gnosis: Music In Esoteric Societies, Justin Andrew Owen

LSU Doctoral Dissertations

Western esotericism, or the practice of trying to understand divinity through secret initiatic means, exists in several philosophical strains, which mystics through the ages have formalized into systems of teaching. One aspect that appears in many of the traditions is music. Music is a direct language of the consciousness within esoteric traditions because it does not rely on language to express higher concepts. Just as these societies teach truths mainly through symbolism, they use music, since it lends itself to interpretations beyond the connotation-laden nature of words. This dissertation focuses on three major strains of western esotericism: Rosicrucians, Theosophists, and …

Extended Measurement Of The Cosmic-Ray Electron And Positron Spectrum From 11 Gev To 4.8 Tev 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, S. Bonechi, M. Bongi, P. Brogi, J. H. Buckley, N. Cannady, G. Castellini, C. Checchia, M. L. Cherry, G. Collazuol, V. Di Felice, K. Ebisawa, H. Fuke, T. G. Guzik, T. Hams, M. Hareyama, N. Hasebe, K. Hibino, M. Ichimura, K. Ioka, W. Ishizaki, M. H. Israel, K. Kasahara, J. Kataoka, R. Kataoka, Y. Katayose

Faculty Publications

Extended results on the cosmic-ray electron + positron spectrum from 11 GeV to 4.8 TeV are presented based on observations with the Calorimetric Electron Telescope (CALET) on the International Space Station utilizing the data up to November 2017. The analysis uses the full detector acceptance at high energies, approximately doubling the statistics compared to the previous result. CALET is an all-calorimetric instrument with a total thickness of 30 X0 at normal incidence and fine imaging capability, designed to achieve large proton rejection and excellent energy resolution well into the TeV energy region. The observed energy spectrum in the region below …

Unavoidable Immersions And Intertwines Of Graphs, Matthew Christopher Barnes

LSU Doctoral Dissertations

The topological minor and the minor relations are well-studied binary relations on the class of graphs. A natural weakening of the topological minor relation is an immersion. An immersion of a graph H into a graph G is a map that injects the vertex set of H into the vertex set of G such that edges between vertices of H are represented by pairwise-edge-disjoint paths of G. In this dissertation, we present two results: the first giving a set of unavoidable immersions of large 3-edge-connected graphs and the second on immersion intertwines of infinite graphs. These results, along with …

Backstepping And Sequential Predictors For Control Systems, Jerome Avery Weston

LSU Doctoral Dissertations

We provide new methods in mathematical control theory for two significant classes of control systems with time delays, based on backstepping and sequential prediction. Our bounded backstepping results ensure global asymptotic stability for partially linear systems with an arbitrarily large number of integrators. We also build sequential predictors for time-varying linear systems with time-varying delays in the control, sampling in the control, and time-varying measurement delays. Our bounded backstepping results are novel because of their use of converging-input-converging-state conditions, which make it possible to solve feedback stabilization problems under input delays and under boundedness conditions on the feedback control. Our …

Dimers On Cylinders Over Dynkin Diagrams And Cluster Algebras, Maitreyee Chandramohan Kulkarni

LSU Doctoral Dissertations

This dissertation describes a general setting for dimer models on cylinders over Dynkin diagrams which in type A reduces to the well-studied case of dimer models on a disc. We prove that all Berenstein--Fomin--Zelevinsky quivers for Schubert cells in a symmetric Kac--Moody algebra give rise to dimer models on the cylinder over the corresponding Dynkin diagram. We also give an independent proof of a result of Buan, Iyama, Reiten and Smith that the corresponding superpotentials are rigid using the dimer model structure of the quivers.

Invariant Of Noncommutative Algebras And Poisson Geometry, Bach Van Nguyen

LSU Doctoral Dissertations

In this dissertation, we describe the structure of discriminant of noncommutative algebras using the theory of Poisson quantization and ring theoretic properties of Poisson algebra. In particular, under appropriate conditions, we express the discriminant of specialization of K[q^{+-1}]-algebras as product of Poisson prime elements in some Poisson central subalgebra. In addition, we provide methods for computing noncommutative discriminant in various settings using results obtained for specialization of K[q^{+-1}]-algebras. Further, to demonstrate, we explicitly compute the discriminant of algebra of quantum matrices and quantum Schubert cell algebras specializing at roots of unity. This dissertation is part of the collaboration with Trampel …

A Study Of Scalability And Cost-Effectiveness Of Large-Scale Scientific Applications Over Heterogeneous Computing Environment, Arghya K. Das

LSU Doctoral Dissertations

Recent advances in large-scale experimental facilities ushered in an era of data-driven science. These large-scale data increase the opportunity to answer many fundamental questions in basic science. However, these data pose new challenges to the scientific community in terms of their optimal processing and transfer. Consequently, scientists are in dire need of robust high performance computing (HPC) solutions that can scale with terabytes of data.

In this thesis, I address the challenges in three major aspects of scientific big data processing as follows: 1) Developing scalable software and algorithms for data- and compute-intensive scientific applications. 2) Proposing new cluster architectures …

Relaxations Of Gf(4)-Representable Matroids, Ben Clark, James Oxley, Stefan H.M. Van Zwam

Faculty Publications

We consider the GF(4)-representable matroids with a circuit-hyperplane such that the matroid obtained by relaxing the circuit-hyperplane is also GF(4)-representable. We characterize the structure of these matroids as an application of structure theorems for the classes of U2,4-fragile and {U2,5, U3,5}-fragile matroids. In addition, we characterize the forbidden submatrices in GF(4)-representations of these matroids.

Investigating Early-Career Teacher Propensity For Arts-Based Pedagogy, Jamie Allison Hipp

LSU Doctoral Dissertations

This study investigates the factors which support the use of arts-based pedagogy in elementary settings. To address the lack of a current profile of an early-career teacher (ECT) with a propensity to use the arts – music, theatre, dance, and visual art – this study illuminates ECT attitudes and behaviors related to arts-based pedagogy. The researcher administered Oreck’s (2001) Teaching with the Arts Survey (TWAS) and employed a non-experimental survey design using purposive sampling. The ECT population studied included currently employed elementary (1-5) teachers who completed the compulsory arts-based pedagogy class at a large Louisiana university in the fall of …

New Platinum(Ii) And Rhenium(I) Complexes Of "Linear" Chelate Ligands Terminated With Pyridyl Or Imidazolyl N-Donor Groups, Himali Kokila Ranasinghe Pilana Vithanage

LSU Doctoral Dissertations

The overall goal of this dissertation research is to design, synthesize, and study new Pt(II) and Re(I) complexes relevant to biomedical applications. One of the projects involves the assessment of the interactions of bulky tridentate carrier ligands with a bound guanine nucleobase derivative (G) in platinum complexes, with a goal of developing chemistry potentially relevant to active anti-cancer Pt drugs. In another project, the fac-[Re^I(CO)₃]⁺ core is used to prepare novel Re(I) complexes with the purpose of developing new linking chemistry relevant to ^99mTc and ¹⁸⁷Re radiopharmaceuticals. This research explores …

Spectra Of Quantum Trees And Orthogonal Polynomials, Zhaoxia Wang

LSU Doctoral Dissertations

We investigate the spectrum of regular quantum-graph trees, where the edges are endowed with a Schr\"odinger operator with self-adjoint Robin vertex conditions. It is known that, for large eigenvalues, the Robin spectrum approaches the Neumann spectrum. In this research, we compute the lower Robin spectrum. The spectrum can be obtained from the roots of a sequence of orthogonal polynomials involving two variables. As the length of the quantum tree increases, the spectrum approaches a band-gap structure. We find that the lowest band tends to minus infinity as the Robin parameter increases, whereas the rest of the bands remain positive. Unexpectedly, …

A Coupled Thermo-Mechanical Theory Of Strain Gradient Plasticity For Small And Finite Deformations, Yooseob Song

LSU Doctoral Dissertations

In this work, a thermodynamically consistent coupled thermo-mechanical gradient enhanced continuum plasticity theory is developed for small and finite deformations. The proposed model is conceptually based on the dislocations interaction mechanisms and thermal activation energy. The thermodynamic conjugate microstresses are decomposed into energetic and dissipative components. This work incorporates the thermal and mechanical responses of microsystems. It addresses phenomena such as size and boundary effects and in particular microscale heat transfer in fast-transient processes. Not only the partial heat dissipation caused by the fast transient time, but also the distribution of temperature caused by the transition from the plastic work …

Madden-Julian Oscillation Relationships With Cool Season Cyclogenesis, Daily Precipitation, And Cool Season Severe Weather Frequencies In The Gulf Of Mexico Region, Stephen Paul Caparotta

LSU Doctoral Dissertations

Tropical cyclone variability in the Gulf of Mexico (GoM) has been the focus of a considerable amount of research. Variability on both interannual scales, related to the El Niño-Southern Oscillation (ENSO), and on subseasonal scales, related to the Madden-Julian Oscillation (MJO), is well documented. By contrast, very little research exists on the relationships between the MJO and cool season, non-tropical cyclones in the GoM.

The MJO influence on cool season (October-March) cyclogenesis in the GoM variability is explored here. Additionally, daily precipitation variability and cool season severe weather variability is examined for areas near and just inland of the GoM. …

Changing U.S. Political Climate Influence On The Professional Outlook Of Prospective Teachers, Patrick D. Hales, Nicole Graves, Tony Durr, Mary Browne

Taboo: The Journal of Culture and Education

No abstract provided.

Free-Radical Polymerization Of Acid-Containing Deep Eutectic Solvents, Kylee Fazende

LSU Doctoral Dissertations

The forefront of this study explored polymerization, specifically thermally-initiated, free-radical frontal polymerization of (meth)acrylic acid monomers while the monomers acted as a hydrogen bond donor of a deep eutectic solvent. These frontal polymerizations were shown to exhibit unusual front velocities and, in some cases, lower front temperatures than the frontal polymerization of the neat monomers or systems containing inert analogs in the place of the hydrogen bond acceptor of these monomer-containing deep eutectic solvents. The frontal polymerization will occur with a range of initiator concentrations including ones that were too low for the pure monomer systems to sustain a front. …