Digital Commons Network^™

Data-Driven Nonparametric Joint Chance-Constrained Programming For Power Systems Scheduling, Chutian Wu

LSU Doctoral Dissertations

This dissertation is dedicated to implementing data-driven nonparametric joint chance constraints (JCC) to power system optimization problems. Power generated by renewable sources, such as solar farms, is an uncertain parameter. Several approaches solve optimization under uncertainty, including stochastic programming, robust programming, and chance-constrained programming. Uncertain parameters may not belong to any parametric class of probability functions. Thus, methods that consider such uncertainty as a random variable that fits in a known probability density function (PDF) have limitations. This study focuses on chance-constrained programming under nonparametric or data-driven distributionally robust uncertainty settings.

Studies based on chance-constrained programming usually focus on individual …

Explanation Needed: Understanding The Low Graduation Rates Of Spanish-Speaking English Learners In Southeastern Louisiana, Alice I. Garcia

LSU Doctoral Dissertations

This qualitative research study used the case study method of one-on-one interviews to collect and examine the experiences of former English learners (ELs) who were unable to finish high school in southeastern Louisiana. This study aimed to identify specific factors that, using Everett Lee’s theory, pushed or pulled these ELs from school and affected their ability to graduate. The push factors that were identified included language, inadequate support, academic performance, discrimination, and lack of connection with school and culture. Pull factors that were identified included lack of prior education, immigration, poverty, pregnancy, being far from family, financially supporting family, and …

A Forestry Trade Data Discrepancy Analysis, Morgan Alyce Daigle

LSU Master's Theses

Trade data across multiple databases experience unavailability across some countries/forestry products, inconsistency, and unreliability; and these qualities manifest as discrepancies in the data. Literature provides evidence of discrepancies and inconsistencies within international trade statistics, including documented cases in which they are present within agriculture sector trade.

While researchers have worked to pinpoint factors to explain discrepancies, studies on the forestry trade databases are not as prevalent. Therefore, more research needs to be conducted to identify discrepancies within forest sector products trade data to understand the nature of discrepancies found between different bilateral trading partners.

The goal of this thesis is …

Introduction To Control Engineering, Xiangyu Meng

E-Textbooks

This is an introductory level textbook for control engineering.

Finding Forensic Evidence In The Operating System's Graphical User Interface, Edward X. Wilson Mr.

LSU Master's Theses

A branch of cyber security known as memory forensics focuses on extracting meaningful evidence from system memory. This analysis is often referred to as volatile memory analysis, and is generally performed on memory captures acquired from target systems. Inside of a memory capture is the complete state of a system under investigation, including the contents of currently running as well as previously executed applications. Analysis of this data can reveal a significant amount of activity that occurred on a system since the last reboot. For this research, the Windows operating system is targeted. In particular, the graphical user interface component …

Visual Analytics And Modeling Of Materials Property Data, Diwas Bhattarai

LSU Doctoral Dissertations

Due to significant advancements in experimental and computational techniques, materials data are abundant. To facilitate data-driven research, it calls for a system for managing and sharing data and supporting a set of tools for effective data analysis and modeling. Generally, a given material property M can be considered as a multivariate data problem. The dimensions of M are the values of the property itself, the conditions (pressure P, temperature T, and multi-component composition X) that control the concerned property, and relevant metadata I (source, date).

Here we present a comprehensive database considering both experimental and computational sources …

Flood Risk Assessment For Residences At The Neighborhood Scale By Owner/Occupant Type And First-Floor Height, Ayat Al Assi, Rubayet Bin Mostafiz, Carol J. Friedland, Md Adilur Rahim, Robert V. Rohli

Faculty Publications

Evaluating flood risk is an essential component of understanding and increasing community resilience. A robust approach for quantifying flood risk in terms of average annual loss (AAL) in dollars across multiple homes is needed to provide valuable information for stakeholder decision-making. This research develops a computational framework to evaluate AAL at the neighborhood level by owner/occupant type (i.e., homeowner, landlord, and tenant) for increasing first-floor height (FFH). The AAL values were calculated here by numerically integrating loss-exceedance probability distributions to represent economic annual flood risk to the building, contents, and use. A simple case study for a census block in …

Measurement Of Near-Threshold Proton Branching Ratios In 31s Important For Novae, Sudarsan Balakrishnan

LSU Doctoral Dissertations

Classical novae are stellar explosions that contribute to the nucleosynthesis of isotopes on the proton-rich side of the valley of stability up to ⁴⁰Ca. In ONe novae, the incompletely understood reaction rate of ³⁰P(p,γ)³¹S is known to strongly influence the production rate of several stable isotopes such as ³⁰Si, ³¹P, and ^32,33,34S. A precise measurement of this reaction rate has several potential implications towards matching astrophysical observables to the physical composition of the nova site -- the observed elemental abundance ratios of O/S and S/Al have been suggested as useful `thermometers' to gauge …

Drivers Of Diatom Production And The Legacy Of Eutrophication In Two River Plume Regions Of The Northern Gulf Of Mexico, Jeffrey W. Krause, Adam D. Boyette, Israel A. Marquez, Rebecca A. Pickering, Kanchan Maiti

Faculty Publications

In the northern Gulf of Mexico (nGoM), the Louisiana Shelf (LS) and Mississippi Bight (MB) subregions are influenced by eutrophication to varying degrees. Despite recognition that dissolved silicon may regulate diatom productivity in the nGoM, there is only one published data set reporting biogenic silica (bSiO2) production rates for each subregion. We report that bSiO2 production rates on the LS and MB are high and appear to be controlled by different nutrients among seasons. Despite exceptional upper trophic level biomass regionally, which suggests significant primary production by diatoms (as in other systems), gross euphotic-zone integrated bSiO2 production rates are lower …

Dissolved Organic Carbon Dynamics And Fluxes In Mississippi-Atchafalaya Deltaic System Impacted By An Extreme Flood Event And Hurricanes: A Multi-Satellite Approach Using Sentinel-2/3 And Landsat-8/9 Data, Bingqing Liu, Eurico J. D’Sa, Francesca Messina, Melissa M. Baustian, Kanchan Maiti, Victor H. Rivera-Monroy, Wei Huang, Ioannis Y. Georgiou

Faculty Publications

Transport of riverine and wetland-derived dissolved organic carbon (DOC) spanning tidal wetlands, estuaries, and continental shelf waters functionally connects terrestrial and aquatic carbon reservoirs, yet the magnitude and ecological significance of this variable and its spatiotemporal linkage remains uncertain for coastal deltaic regions, such as Mississippi River Delta Plain, which includes Mississippi (MR) and Atchafalaya (AR) rivers and estuaries with vast expanses of wetlands and coastal forests. We examined DOC dynamics and fluxes in this large river-dominated wetland-estuarine system for the period between 2019 and 2021 that included an extreme river flood event in 2019, two major hurricanes (Barry in …

Design And Field-Scale Demonstration Of The Buoyant-Kill Process For Restoring Integrity Of Wells With Sustained Casing Pressure, Efecan Demirci, Andrew Wojtanowicz

Faculty Publications

Sustained Casing Pressure (SCP) is the persistent casinghead pressure resulting from the well’s annular integrity loss and migration of gas above the leaking cement sheath. Downhole—intervention methods for SCP removal employ workover rigs to access and plug off the leaking annulus at depth from within the well. The inexpensive rig-less method of Buoyant Kill involves surface injection of immiscible heavy fluid at the casinghead into the well’s annulus to replace the annular fluid column above the gas-leaking cement and stop gas migration. Laboratory and pilot-size testing have shown feasibility of the method. Presented here, is a field-scale demonstration experiment conducted …

Lighting Energy Load Prediction Framework Using Agent-Based Simulation And Artificial Neural Network Models, Sorena Vosoughkhosravi, Seddigheh Norouziasl, Amirhosein Jafari

Faculty Publications

Lighting is responsible for 17% of the total electricity consumption in commercial buildings in the United States. Investigating the lighting energy load provides the potential for more energy-saving in commercial buildings. Nonetheless, the development of lighting load prediction models has received limited attention in extant literature. This study proposes a framework to predict the lighting schedule and load in office buildings by integrating an agent-based model into an artificial neural network model. A small office building is used as a case study to simulate lighting load based on occupancy information using an agent-based model. Then, an artificial neural network model …

Joint Estimation Of Neural Events And Hemodynamic Response Functions From Task Fmri Via Convolutional Neural Networks, Kai Cheng Chuang, Sreekrishna Ramakrishnapillai, Krystal Kirby, Arend W.A. Van Gemmert, Lydia Bazzano, Owen T. Carmichael

Clinical Research Faculty Publications

Joint decomposition of functional magnetic resonance imaging (fMRI) time series into time courses of neural activity events and hemodynamic response functions (HRF) can enable new insights into functional connectivity, task activation, and neurovascular coupling in health and disease. Current methods for this problem handle time series of either temporally isolated events or extended blocks of continuous events but not both; and they constrain the HRF to one specific functional form. We propose to use an autoencoder and a convolutional neural network (CNN) to overcome these challenges. The autoencoder uses convolutional neural networks to reconstruct the fMRI time series while estimating …

Preliminary Findings From A Collaborative Storytelling Program On Life Participation And Communication Among Persons With Aphasia, Bijoyaa Mohapatra, Ranjini Mohan

Faculty Publications

Aims: The purpose of this study is to evaluate the outcomes of a remotely delivered collaborative storytelling program based on the TimeslipsTM approach in persons with aphasia (PWA). The program aims to improve social interaction, communication, and participation through a guided experience. Methods: Six PWA of mild-moderate severity and of fluent and nonfluent types participated in the program twice a week for seven weeks. They collaboratively created 28 free-form stories from staged pictures. PWA were tested pre- and post-treatment on several validated outcome measures representing each of the Living with Aphasia: Framework for Outcome Measurement (A-FROM) domains. PWA self-rated on …

Effects Of Ketone Bodies On Energy Expenditure, Substrate Utilization, And Energy Intake In Humans, Rodrigo Fernández-Verdejo, Jacob T. Mey, Eric Ravussin

Division of Basic Science Faculty Publications

The potential of ketogenic approaches to regulate energy balance has recently gained attention since ketones may influence both energy expenditure and energy intake. In this narrative review, we summarized the most relevant evidence about the role of ketosis on energy expenditure, substrate utilization, and energy intake in humans. We considered different strategies to induce ketosis, such as fasting, dietary manipulation, and exogenous ketone sources. In general, ketosis does not have a major influence on energy expenditure but promotes a shift in substrate utilization towards ketone body oxidation. The strategies to induce ketosis by reduction of dietary carbohydrate availability (e.g., ketogenic …

Mmst-Vit: Climate Change-Aware Crop Yield Prediction Via Multi-Modal Spatial-Temporal Vision Transformer, Fudong Lin, Summer Crawford, Kaleb Guillot, Yihe Zhang, Yan Chen, Xu Yuan, Li Chen, Shelby Williams, Robert Minvielle, Xiangming Xiao, Drew Gholson, Nicolas Ashwell, Tri Setiyono, Brenda Tubana, Lu Peng, Magdy Bayoumi, Nian Feng Tzeng

Faculty Publications

Precise crop yield prediction provides valuable information for agricultural planning and decision-making processes. However, timely predicting crop yields remains challenging as crop growth is sensitive to growing season weather variation and climate change. In this work, we develop a deep learning-based solution, namely Multi-Modal Spatial-Temporal Vision Transformer (MMST-ViT), for predicting crop yields at the county level across the United States, by considering the effects of short-term meteorological variations during the growing season and the long-term climate change on crops. Specifically, our MMST-ViT consists of a Multi-Modal Transformer, a Spatial Transformer, and a Temporal Transformer. The Multi-Modal Transformer leverages both visual …

Wooing “Willing Dupes”: The Bush Administration’S Use Of Emotional Language In The Drive Toward War With Iraq, Michael F. Russo

Faculty Publications

The publicly available texts of the George W. Bush administration from September 11, 2001, to March 19, 2003, as presented in The Public Papers of the Presidents of the United States, were analyzed for word frequency and the words themselves analyzed for emotional weight using the NRC Emotion Intensity Lexicon. Transcripts of six television news agencies (ABC, CBS, NBC, CNN, FOX, and PBS) were also analyzed for word frequency to determine the extent to which these agencies may have repeated and consequently amplified the rhetoric of the administration. Public opinion polling for this same period was examined in an …

Gene-Educational Attainment Interactions In A Multi-Population Genome-Wide Meta-Analysis Identify Novel Lipid Loci, Lisa De Las Fuentes, Karen L. Schwander, Michael R. Brown, Amy R. Bentley, Thomas W. Winkler, Yun Ju Sung, Patricia B. Munroe, Clint L. Miller, Hugo Aschard, Stella Aslibekyan, Traci M. Bartz, Lawrence F. Bielak, Jin Fang Chai, Ching Yu Cheng, Rajkumar Dorajoo, Mary F. Feitosa, Xiuqing Guo, Fernando P. Hartwig, Andrea Horimoto, Ivana Kolčić, Elise Lim, Yongmei Liu, Alisa K. Manning, Jonathan Marten, Solomon K. Musani, Raymond Noordam, Sandosh Padmanabhan, Tuomo Rankinen, Melissa A. Richard, Paul M. Ridker, Albert V. Smith, Dina Vojinovic, Alan B. Zonderman

Faculty Publications

Introduction: Educational attainment, widely used in epidemiologic studies as a surrogate for socioeconomic status, is a predictor of cardiovascular health outcomes. Methods: A two-stage genome-wide meta-analysis of low-density lipoprotein cholesterol (LDL), high-density lipoprotein cholesterol (HDL), and triglyceride (TG) levels was performed while accounting for gene-educational attainment interactions in up to 226,315 individuals from five population groups. We considered two educational attainment variables: “Some College” (yes/no, for any education beyond high school) and “Graduated College” (yes/no, for completing a 4-year college degree). Genome-wide significant (p < 5 × 10−8) and suggestive (p < 1 × 10−6) variants were identified in Stage 1 (in up to 108,784 individuals) through genome-wide analysis, and those variants were followed up in Stage 2 studies (in up to 117,531 individuals). Results: In combined analysis of Stages 1 and 2, we identified 18 novel lipid loci (nine for LDL, seven for HDL, and two for TG) by two degree-of-freedom (2 DF) joint tests of main and interaction effects. Four loci showed significant interaction with educational attainment. Two loci were significant only in cross-population analyses. Several loci include genes with known or suggested roles in adipose (FOXP1, MBOAT4, SKP2, STIM1, STX4), brain (BRI3, FILIP1, FOXP1, LINC00290, LMTK2, MBOAT4, MYO6, SENP6, SRGAP3, STIM1, TMEM167A, TMEM30A), and liver (BRI3, FOXP1) biology, highlighting the potential importance of brain-adipose-liver communication in the regulation of lipid metabolism. An investigation of the potential druggability of genes in identified loci resulted in five gene targets shown to interact with drugs approved by the Food and Drug Administration, including genes with roles in adipose and brain tissue. Discussion: Genome-wide interaction analysis of educational attainment identified novel lipid loci not previously detected by analyses limited to main genetic effects.

Charting The Course To Advance Dei In The Ocean Sciences A Case Study, Christopher F. D’Elia, Katherine Falls, Sibel Bargu, Linda Hooper-Bùi

Faculty Publications

The Louisiana State University College of the Coast & Environment (LSU CC&E) developed a multi-faceted strategic initiative to increase its diversity, equity, and inclusion. Elements of this initiative began one-by-one over the last decade and were aggregated into a comprehensive implementation plan—the 2020 CC&E Diversity, Equity, and Inclusion Action Plan. Based on best practices in the “physical sciences” (i.e., geosciences, including oceanography), the plan aims to augment recruitment and retention using limited resources and personnel. The long-range goal is to increase the number of PhD graduates from underrepresented groups by employing strategies that start at the 6–12th grade level. The …

Quasistatic Evolution With Unstable Forces, Debdeep Bhattacharya, Robert P. Lipton

Faculty Publications

We consider load controlled quasistatic evolution. Well posedness results for the nonlocal continuum model related to peridynamics are established. We show local existence and uniqueness of quasistatic evolution for load paths originating at stable critical points. These points can be associated with local energy minima among the convex set of deformations belonging to the strength domain of the material. The evolution of the displacements, however, is not constrained to lie inside the strength domain of the material. The load-controlled evolution is shown to exhibit energy balance.

Simulating Grain Shape Effects And Damage In Granular Media Using Peridem, Debdeep Bhattacharya, Robert P. Lipton

Faculty Publications

We provide a numerical platform for the analysis of particle shape and topology effect on the macroscopic behavior of granular media. We work within a discrete element method (DEM) framework and apply a peridynamic model for deformable particles accounting for deformation and damage of individual particles. To accommodate arbitrary particle shapes including nonconvex ones as well as particle topology, an efficient method is developed to keep intraparticle peridynamic interaction within particle boundaries. Particle contact with the rigid boundary wall is computed analytically to improve accuracy. To speed up simulations with particles of different shapes and sizes the initial configuration is …

Local Observer For Parameters And For State Variables Of Nonlinear Systems, Frederic Mazenc, Michael Malisoff

Faculty Publications

We provide new observer designs to simultaneously identify parameters and states of systems whose nonlinearities have order two near the origin, which include cubic terms arising in the study of jump phenomena, process control, and bistable models of aerospace systems. This yields local exponential convergence of the state estimation error to zero, basin of attraction estimates, and fixed time parameter identification. We illustrate our result using Duffing's equation, whose cubic term puts it outside the scope of prior methods.

Discrete-Time Trajectory-Based Stabilization Approach Using Interval Observer, Frederic Mazenc, Michael Malisoff, Jackson Knox

Faculty Publications

We provide a discrete-time vector valued analog of recently developed continuous-time trajectory-based estimates. We use it to provide a discrete-time version of Halanay's inequality. We combine the results with interval observers to prove exponential stability properties for discrete-time linear systems with uncertainties whose arbitrarily long input delays are compensated for by reduction model controls, and a robust global exponential stability result for observers for discrete-time linear systems.

Reference Governor Design In The Presence Of Uncertain Polynomial Constraints, Rick Schieni, Chengwei Zhao, Michael Malisoff, Laurent Burlion

Faculty Publications

Reference governors are add-on schemes that are used to modify trajectories to prevent controlled dynamical systems from violating input or state constraints, and so are playing an increasingly important role in aerospace, robotic, and other applications. Here we present a novel reference governor design for systems whose polynomial constraints depend on unknown bounded parameters. This is a significant departure from earlier treatments of reference governors, where the constraints were linear or known, because here we transfer the uncertainties into the constraints instead of having them in the closed loop dynamics, which greatly simplifies the task of determining future evolution of …

Almost Fixed Time Observers For Parameters And For State Variables Of Nonlinear Systems, Frederic Mazenc, Michael Malisoff, Laurent Burlion

Faculty Publications

We provide new finite-time and fast-converging observers for continuous-time nonlinear systems that contain unknown constant parameters and measurement delays. When the dynamics are affine in the unmeasured state, we obtain fixed time observers that identify unknown states and unknown model parameters. When the dynamics contain a nonlinearity that depends on the unmeasured state, we instead obtain asymptotic convergence of our observers, whose rate of convergence converges to infinity as the growth rate of this nonlinearity converges to zero, so in this case we call the observers almost fixed time observers. Our examples illustrate how our assumptions can be easily checked.

Mathematical Models Of Topologically Protected Transport In Twisted Bilayer Graphene, Guillaume Bal, Paul Cazeaux, Daniel Massatt, Solomon Quinn

Faculty Publications

Twisted bilayer graphene gives rise to large moir\'e patterns that form a triangular network upon mechanical relaxation. If gating is included, each triangular region has gapped electronic Dirac points that behave as bulk topological insulators with topological indices depending on valley index and the type of stacking. Since each triangle has two oppositely charged valleys, they remain topologically trivial. In this work, we address several questions related to the edge currents of this system by analysis and computation of continuum PDE models. First, we derive the bulk invariants corresponding to a single valley, and then apply a bulk-interface correspondence to …

Uniqueness Of Entire Solutions To Quasilinear Equations Of P-Laplace Type, Nguyen Cong Phuc, Igor E. Verbitsky

Faculty Publications

We prove the uniqueness property for a class of entire solutions to the equation (Formula presented) where σ is a nonnegative locally finite measure in Rⁿ, absolutely continuous with respect to the p-capacity, and div A(x, ∇u) is the A-Laplace operator, under standard growth and monotonicity assumptions of order p (1 < p < ∞) on A(x, ξ) (x, ξ ∈ Rⁿ); the model case A(x, ξ) = ξ|ξ|^p−2 corresponds to the p-Laplace operator ∆p on Rⁿ. Our main results establish uniqueness of solutions to a similar problem,(Formula presented) in the sub-natural growth case 0 < q < p − 1, where µ, σ are nonnegative locally finite measures in Rⁿ, absolutely continuous with respect to the …

An Upper Bound For The Circumference Of A 3-Connected Binary Matroid, Manoel Lemos, James Oxley

Faculty Publications

Jim Geelen and Peter Nelson proved that, for a loopless connected binary ma-troid M with an odd circuit, if a largest odd circuit of M has k elements, then a largest circuit of M has at most 2k − 2 elements. The goal of this note is to show that, when M is 3-connected, either M has a spanning circuit, or a largest circuit of M has at most 2k − 4 elements. Moreover, the latter holds when M is regular of rank at least four.

Generalizing Cographs To 2-Cographs, James Oxley, Jagdeep Singh

Faculty Publications

A graph in which every connected induced subgraph has a disconnected complement is called a cograph. Such graphs are precisely the graphs that do not have the 4-vertex path as an induced subgraph. We define a 2-cograph to be a graph in which the complement of every 2-connected induced subgraph is not 2-connected. We show that, like cographs, 2-cographs can be recursively defined and are closed under induced minors. We characterize the class of non-2-cographs for which every proper induced minor is a 2-cograph. We further find the finitely many members of this class whose complements are also induced-minor-minimal non-2-cographs.

The Lagrangian Numerical Relativity Code Sphincs_Bssn_V1.0, Stephan Rosswog, Francesco Torsello, Peter Diener

Faculty Publications

We present version 1.0 of our Lagrangian numerical relativity code SPHINCS_BSSN. This code evolves the full set of Einstein equations, but contrary to other numerical relativity codes, it evolves the matter fluid via Lagrangian particles in the framework of a high-accuracy version of smooth particle hydrodynamics (SPH). The major new elements introduced here are: (i) a new method to map the stress–energy tensor (known at the particles) to the spacetime mesh, based on a local regression estimate; (ii) additional measures that ensure the robust evolution of a neutron star through its collapse to a black hole; and (iii) further refinements …