Digital Commons Network^™

Iss Inequalities For Vector Versions Of Halanay's Inequality And Of The Trajectory-Based Approach, Frédéric Mazenc, Michael Malisoff

Faculty Publications

Halanay's inequality is a powerful and widely used tool to prove asymptotic convergence properties of functions that arise in the study of systems with delays or continuous-discrete features. In its standard form, it applies to scalar valued functions that satisfy decay conditions, with overshoots depending on suprema of the functions over suitable intervals. Then it provides an exponential decay estimate on the scalar functions. Here, we provide vector versions of Halanay's inequality, and of the so-called trajectory based approach, both yielding input-to-state stability (or ISS) inequalities. Our proofs of the inequalities use the theory of positive systems. We apply our …

Multiscale Analysis Of Cancer Service Areas In The United States, Changzhen Wang, Tracy Onega, Fahui Wang

Faculty Publications

The purpose of delineating Cancer Service Areas (CSAs) is to define a reliable unit of analysis, more meaningful than geopolitical units such as states and counties, for examining geographic variations of the cancer care markets using geographic information systems (GIS). This study aims to provide a multiscale analysis of the U.S. cancer care markets based on the 2014–2015 Medicare claims of cancer-directed surgery, chemotherapy, and radiation. The CSAs are delineated by a scale-flexible network community detection algorithm automated in GIS so that the patient flows are maximized within CSAs and minimized between them. The multiscale CSAs include those comparable in …

Snapshots Of Coastal Ecology During Glacial And Deglacial Intervals: A Multiproxy Assessment Of Northern Gulf Of Mexico Sediment Cores, Kendall Emilie Brome

LSU Master's Theses

Terrestrial ecosystems along exposed continental shelves during times of relatively low sea level and glaciation are rarely preserved due to the mechanically erosive nature of marine transgression and regression. In this study, I investigate the geochemical and palynological characteristics of two well-preserved sites in the northern Gulf of Mexico (NGOM) to determine the ecologic settings and subsequent mechanisms of preservation in this region. Both sites contain preserved terrigenous sediments of previously exposed coastal margins; the first is located at the Alabama Underwater Forest (~13 km south of Gulf Shores, AL, at ~15 mbsl), and optically stimulated luminescence dates to 72–56 …

Subpredictor Approach For Event-Triggered Control Of Discrete-Time Systems With Input Delays, Frédéric Mazenc, Michael Malisoff, Corina Barbalata, Zhong Ping Jiang

Faculty Publications

We propose a new output event-triggered control design for linear discrete-time systems with constant arbitrarily long input delays, using delay compensating subpredictors. We prove input-to-state stability of the closed loop system, using framers and the theory of positive systems. A novel feature of our approach is our use of matrices of absolute values, instead of Euclidean norms, in our discrete-time event triggers for our delay compensating control design. We illustrate our approach using a model of the BlueROV2 marine vehicle, where our new event triggers lead to a smaller number of control recomputation times as compared with standard event triggers …

Time-Varying Rates Of Organic And Inorganic Mass Accumulation In Louisiana Marshes And Relation To Sea-Level Change, Sophie Vincent

LSU Master's Theses

Louisiana wetlands are complex systems that require a continuous input of organic and inorganic material to keep pace with relative sea-level rise (RSLR). Marshes, specifically, rely on organic material to build soil volume and maintain surface elevation. Interannual-to-decadal sea-level anomalies induced by Earth's internal climate variability and atmospheric disturbances such as hurricanes can affect marsh accretion, mineral deposition, and plant productivity. Coastal restoration projects such as sediment diversions are in progress to mitigate land loss and increase availability of inorganic sediment to coastal wetlands. The goal of this project is to determine if organic mass accumulation rates in Louisiana marshes …

Improvements To The Automatic Calibration Of Digital Focusing Color Schlieren Systems, Robert C. Frazee

LSU Master's Theses

As a diagnostic method, Schlieren imaging offers the unique ability to visualize flows with a completely non-intrusive method. By visualizing small changes in the refractive index of a fluid, Schlieren imaging is able to visualize changes in temperature, pressure, and composition. While historic Schlieren methods have been limited to providing largely qualitative information, modern Schlieren methods are able to extract quantitative information from flow phenomena. This is possible through either Background Oriented Schlieren (BOS) or Digital Focusing Color Schlieren (DFCS) methods. While BOS is relatively flexible, it requires a large amount of computational effort to process each frame of captured …

Polymer Mimetics For Soil Modeling And Detection Of Biomarkers, Md Ragib Hasan

LSU Doctoral Dissertations

The population of the world is increasing day by day and is expected to reach 9.8 billion by the year 2050. The ever-increasing demand for agricultural products is putting an unprecedented strain on the world's soils as the human population continues to expand. Soil degradation caused by over-farming and the agrochemicals (fertilizers, pesticides, etc.) used in agriculture is a growing problem, although its causes remain murky. In addition, little is understood about the molecular-level interactions of substances that are subsequently introduced to soils, such as agricultural chemicals (ACs). Therefore, it is expected that these constraints may be circumvented by the …

Impact Of The Choice Of Acidic Buffers On The Electrochemical Reduction Of Hexavalent Chromium In Water, Devin D. Meche

Honors Capstones

No abstract provided.

We Are All Connected, Behnoush Tavasolinia

LSU Master's Theses

Upon personal reflection, I have discovered that economic, cultural, and social issues have become very important in my life. As an Iranian graphic designer, I used current events and responded to Iranian stories to reflect that people’s problems anywhere in the world affect other people’s lives worldwide. My thesis investigation aims to reveal the global connection with commodities by focusing on Iran’s economic inflation to create a conceptual and visual representation of impacted consumables. Persian rugs and tile designs are the centers of the culture and symbols of the Iranian people. I used graphic design to illustrate tiles utilizing economic …

Investigating The Relational Element Of Trust In Teacher-Principal Relationships: An Autoethnographic Case Study, Angela Bradley

LSU Doctoral Dissertations

This autoethnographic case study was designed to investigate the relational aspect of trust, a characteristic of servant leadership, in the teacher-principal relationship. This trusting bond is an often overlooked, foundational element of a school’s success. I examined the role that trust plays in enhancing a school’s culture and how trust is established and maintained among one principal and teachers under my supervision. In addition, as researcher, I sought to uncover specific indicators that trust was present on a school campus. Finally, I sought to examine trust’s effects on collaboration and organizational commitment.

Through weekly reflections, I sought to examine my …

Hydrogeologic Investigation Of A Covered Karst Terrain, Joseph Peter Honings

LSU Doctoral Dissertations

Increasing demand for water for agricultural use within the Dougherty Plain of the Southeastern United States has depleted surface water bodies. In karstic landscapes, such as the Dougherty Plain in southwest Georgia where the linkages between surface and ground waters are close, there is a need to understand the physical characteristics of the subsurface that allow these close linkages. Having a better understanding of the subsurface characteristics will aid numerical modeling efforts that underpin policy decisions and economic analyses. Two common features on this karstic landscape are draws and geographically isolated wetlands. Using LiDAR, aerial imagery, and ground-penetrating radar, this …

Defining Change Beyond A Binary System: Measurement And Interpretation Of Degrees Of Dysphonia Severity In The Individual And Across Voice Disorders, Lindsey Ann Parker

LSU Doctoral Dissertations

Objective: The current study examined the sensitivity of voice outcome measures in discriminating cut-off thresholds between degrees of dysphonia severity, correlations to perceived dysphonia, and the impact of vocal task. Differences between cases of adductor spasmodic dysphonia, benign vocal fold polyps, and unilateral vocal fold paralysis were also explored.

Method: Auditory-perceptual judgments were performed by three raters for four diagnostic groups: Normal (n=14), AdSD (n=15), Polyp (n=15) and UVFP (n=15). Receiver operator characteristic area under the curve (AUC) analyses established screening and dysphonia severity (mild, moderate, severe) cut-off thresholds for auditory-perceptual visual analog scale (VAS) ratings and acoustic measures (f0_SD, …

Ribbon Homology Cobordisms, Aliakbar Daemi, Tye Lidman, David Shea Vela-Vick, C. M.Michael Wong

Faculty Publications

We study 4-dimensional homology cobordisms without 3-handles, showing that they interact nicely with Thurston geometries, character varieties, and instanton and Heegaard Floer homologies. Using these, we derive obstructions to such cobordisms. As one example of these obstructions, we generalize other recent results on the behavior of knot Floer homology under ribbon concordances. Finally, we provide topological applications, including to Dehn surgery problems.

Device Free Indoor Localization Of Human Target Using Wifi Fingerprinting, Prasanga Neupane

LSU Master's Theses

Indoor localization of human objects has many important applications nowadays. Proposed here is a new device free approach where all the transceiver devices are fixed in an indoor environment so that the human target doesn't need to carry any transceiver device with them. This work proposes radio-frequency fingerprinting for the localization of human targets which makes this even more convenient as radio-frequency wireless signals can be easily acquired using an existing wireless network in an indoor environment. This work explores different avenues for optimal and effective placement of transmitter devices for better localization. In this work, an experimental environment is …

The Degree Gini Index Of Several Classes Of Random Trees And Their Poissonized Counterparts—Evidence For Duality, Carly Domicolo, Panpan Zhang, Hosam Mahmoud

Journal of Stochastic Analysis

No abstract provided.

Experience That Works: An Investigation Uncovering Essential Elements Of Field Experiences And Internships Within Principal Preparation Programs That Significantly Impact And Contribute To Principal Effectiveness, Nathan Wayne Hite

LSU Doctoral Dissertations

This study applied situational leadership and transformational leadership theories to discern essential elements of principal preparation program field experiences and internships that contributed most to principal effectiveness. Identifying critical components of principal preparation field experiences and internships were imperative to ensure principal effectiveness within the ever-changing landscape of education. The objective of this study was to discover essential components of field experiences and internships provided by principal preparation programs that contributed most to principal effectiveness, increasing the likelihood public school districts hired principal candidates who were equipped with the skills necessary to step into the position with minimal on-the-job training. …

A Cluster Structure On The Coordinate Ring Of Partial Flag Varieties, Fayadh Kadhem

LSU Doctoral Dissertations

The main goal of this dissertation is to show that the (multi-homogeneous) coordinate ring of a partial flag variety C[G/P_K^−] contains a cluster algebra for every semisimple complex algebraic group G. We use derivation properties and a canonical lifting map to prove that the cluster algebra structure A of the coordinate ring C[N_K] of a Schubert cell constructed by Goodearl and Yakimov can be lifted, in an explicit way, to a cluster structure \hat{A} living in the coordinate ring of the corresponding partial flag variety. Then we use a minimality condition to prove that the cluster algebra \hat{A} is equal …

Synthesis Of Carbon Nanohoops And Macrocycles Via Alkyne Metathesis, Xin Zhou

LSU Doctoral Dissertations

Cycloparaphenyleneacetylene (CPPA) and cycloparaphenylene (CPP) are called carbon nanohoops; they are fully conjugated macrocycles with radially oriented aromatic groups. Though many syntheses of CPPA and CPP were reported, in the macrocyclization step, the yields were usually not satisfying, as the reactions were irreversible. Our group utilizes alkyne metathesis to address this problem. Chapter 1 provides backgrounds and an introduction to the carbon nanohoops and alkyne metathesis.

Chapter 2 details the synthesis of the [3]CPP⁴A and [3]CPP⁵A, with good macrocyclization yields via alkyne metathesis. This study showed the error-correction ability of alkyne metathesis, especially with nonsymmetric substrates. …

Controlling Electro-Magnetic Functionality Of Ruthenates By Heterostructure Design, Zeeshan Ali

LSU Doctoral Dissertations

Perovskite oxides (ABO₃) show wide range of functionalities originating from interplay of structural, spin, charge, and orbital degrees of freedoms. The bulk perovskite structure could be controlled via conventional chemical substitution, though exploiting heterostructure engineering novel ground states could be observed which otherwise are absent in bulk. In this thesis, the interest is to explore the electro-magnetic phenomena as complex oxides are confined in heterostructures.

I first investigate electromagnetic properties of ultrathin epitaxial ruthenate: SrRuO₃ (SRO); spatially confined between SrTiO₃ (STO) i.e., STO⁵-SROⁿ-STO⁵ with n = 1- and 2-unit cells. It …

A Sharp Rate Of Convergence In The Functional Central Limit Theorem With Gaussian Input, S.V. Lototsky

Journal of Stochastic Analysis

No abstract provided.

Investigating The Theoretical Orientations Of Select Louisiana Preservice Teachers Regarding Teaching Reading: A Mixed-Methods Study, Megan Jenny

LSU Doctoral Dissertations

Teacher quality is one of the most significant factors contributing to student success, and Teacher Preparation Programs (TPPs) are traditionally responsible for teaching preservice teachers how to teach reading. Effective reading instruction is responsive, complex, and equitable. Acknowledgement of a disconnect between preparation programming and critical teacher knowledge for teachers of reading indicated a need for this exploratory mixed-methods study. The purpose of the current study, grounded by the theoretical framework of Sociocultural Theory, was to investigate what a select group of 21 preservice grades 1-3 elementary teachers were taught about teaching reading, preservice teachers’ theoretical orientations for teaching reading, …

A Numerical And Machine Learning Investigation Of Water Quality In The Northern Gulf Of Mexico, From Estuaries To Shelf, Yanda Ou

LSU Doctoral Dissertations

In this study, numerical and machine learning (ML) models are developed and adapted to investigate the water quality of the Barataria Estuary and the Louisiana-Texas (LaTex) Shelf in northern Gulf of Mexico. By using a 3-D hydrodynamic ROMS model, the salinity variability of the Barataria Estuary is found highly influenced by the Mississippi River discharges and man-made river diversion systems. The Mississippi River freshwater can intrude into the estuary through the middle and the east passes. Sensitivity tests indicate that decreases in lower estuarine salinity due to the elevated Mississippi River discharges are more apparent than the salinity increases due …

Quantization Of The Free Poisson Central Limit Theorem, Yungang Lu

Journal of Stochastic Analysis

No abstract provided.

An Automated Pipeline For Scattered Light Noise Characterization, Stefano Bianchi, Alessandro Longo, Guillermo Valdes, Gabriela González, Wolfango Plastino

Faculty Publications

Scattered light noise (or scattering) affects the sensitivity of gravitational wave detectors in their detection frequency band. The mitigation of such nonlinear and nonstationary noise can be carried out experimentally and employing data analysis techniques, e.g., applying adaptive algorithms to the data affected by noise. We present gwas , a fully automated pipeline based on the time-varying filter empirical mode decomposition (tvf-EMD) algorithm, to identify, characterize, and monitor objects inducing scattering to the gravitational wave detector’s output. The tvf-EMD algorithm is suitable for decomposing signals with time-dependent frequency, such as scattering. The pipeline application to LIGO Livingston data shows that …

Novel Texture-Based Probabilistic Object Recognition And Tracking Techniques For Food Intake Analysis And Traffic Monitoring, Robert Jacob Dibiano

LSU Doctoral Dissertations

More complex image understanding algorithms are increasingly practical in a host of emerging applications. Object tracking has value in surveillance and data farming; and object recognition has applications in surveillance, data management, and industrial automation. In this work we introduce an object recognition application in automated nutritional intake analysis and a tracking application intended for surveillance in low quality videos. Automated food recognition is useful for personal health applications as well as nutritional studies used to improve public health or inform lawmakers. We introduce a complete, end-to-end system for automated food intake measurement. Images taken by a digital camera are …

Are Existing Modeling Tools Useful To Evaluate Outcomes In Mangrove Restoration And Rehabilitation Projects? A Minireview, Victor H. Rivera-Monroy, Xiaochen Zhao, Hongqing Wang, Zuo George Xue

Faculty Publications

Ecosystem modeling is a critical process for understanding complex systems at spatiotemporal scales needed to conserve, manage, and restore ecosystem services (ESs). Although mangrove wetlands are sources of ESs worth billions of dollars, there is a lack of modeling tools. This is reflected in our lack of understanding of mangroves’ functional and structural attributes. Here, we discuss the “state of the art” of mangrove models used in the planning and monitoring of R/R projects during the last 30 years. The main objectives were to characterize the most frequent modeling approach, their spatiotemporal resolution, and their current utility/application in management decisions. …

Coupled Situational Awareness System To Improve Transportation Infrastructure Performance During Extreme Events, Hatim Sharif, Samer Dessouky, Md Jobair Bin Alam, Raghava Kommalapati, Hongbo Du Ph.D

Publications

The dense road networks and numerous low water crossings throughout Texas may be contributing to the higher recurrence rates of floods that pose a danger to vehicles. A timely issue that should be addressed by researchers is the compounding of disaster. Flooding can be combined with other life-threatening occurrences such as power loss and interruptions of health and emergency services. During these events, rescue requests from the stranded communities overwhelm the emergency response facilities; impassable roadways and the paucity of reliable information on the affected areas and their accessibility hamper emergency response operations, causing several detours and delays that put …

Social Influences On Physical Activity For Establishing Criteria Leading To Exercise Persistence, Ensela Mema, Everett S. Spain, Corby K. Martin, James O. Hill, R. Drew Sayer, Howard D. Mcinvale, Lee A. Evans, Nicholas H. Gist, Alexander D. Borowsky, Diana M. Thomas

Clinical Research Faculty Publications

Despite well-documented health benefits from exercise, a study on national trends in achieving the recommended minutes of physical activity guidelines has not improved since the guidelines were published in 2008. Peer interactions have been identified as a critical factor for increasing a population’s physical activity. The objective of this study is for establishing criteria for social influences on physical activity for establishing criteria that lead to exercise persistence. A system of differential equations was developed that projects exercise trends over time. The system includes both social and non-social influences that impact changes in physical activity habits and establishes quantitative conditions …

Event-Triggered Control Of Robotic Fish With Reduced Communication Rate, Wenyu Zuo, Animesh Chakravarthy, Michael Malisoff, Zheng Chen

Faculty Publications

Underwater robots often need to communicate with external localization sensors. The low bandwidth in such communications is one of the bottlenecks in achieving accurate tracking control. Toward this end, we adopt a novel periodic event-triggered control (PETC) which allows a robotic fish to reduce its communication load in tracking a desired heading angle with position feedback from an external sensor. To design the PETC, a linear state-space model is derived from a nonlinear dynamic model of the robotic fish with a small perturbation assumption. The PETC consists of an observer, state-feedback controller, integrator, event-trigger rule, and predictor. The observer and …

Observational Constraints On Anisotropies For Bouncing Alternatives To Inflation, Ivan Agullo, Javier Olmedo, Edward Wilson-Ewing

Faculty Publications

We calculate how primordial anisotropies in the background space-time affect the evolution of cosmological perturbations for bouncing alternatives to inflation, like ekpyrosis and the matter bounce scenario. We find that the leading order effect of anisotropies in the contracting phase of the universe is to induce anisotropies in the cosmic microwave background with a very concrete form: a scale-invariant quadrupolar angular distribution. Sub-leading effects are the generation of higher-order moments in the angular distribution, as well as cross-correlations between scalar and tensor modes. We also find that observational constraints from the cosmic microwave background on the quadrupole moment provide strong …