Digital Commons Network^™

Enabling Flexibility Through Strategic Management Of Complex Engineering Systems, Walter Louis Barnes Ii

Doctoral Dissertations

”Flexibility is a highly desired attribute of many systems operating in changing or uncertain conditions. It is a common theme in complex systems to identify where flexibility is generated within a system and how to model the processes needed to maintain and sustain flexibility. The key research question that is addressed is: how do we create a new definition of workforce flexibility within a human-technology-artificial intelligence environment?

Workforce flexibility is the management of organizational labor capacities and capabilities in operational environments using a broad and diffuse set of tools and approaches to mitigate system imbalances caused by uncertainties or changes. …

Fuzzy Logistic Regression For Detecting Differential Dna Methylation Regions, Tarek M. Bubaker Bennaser

Doctoral Dissertations

“Epigenetics is the study of changes in gene activity or function that are not related to a change in the DNA sequence. DNA methylation is one of the main types of epigenetic modifications, that occur when a methyl chemical group attaches to a cytosine on the DNA sequence. Although the sequence does not change, the addition of a methyl group can change the way genes are expressed and produce different phenotypes. DNA methylation is involved in many biological processes and has important implications in the fields of biomedicine and agriculture.

Statistical methods have been developed to compare DNA methylation at …

History Of Natural And Anthropogenic Activities In Lake Izabal, Eastern Guatemala: Using Geochemical Evidence To Record Recent Contamination, Elisandra Hernandez

Doctoral Dissertations

”Water is essential for human subsistence. Stable freshwater supplies are needed as a source of food, drinking water, for transportation, recreation and economic development. Despite their recognized importance, anthropogenic activities have altered freshwater ecosystems around the world. Lake Izabal is the habitat for diverse aquatic species of flora and fauna, some of which are endemic and endangered. Its importance notwithstanding, anthropogenic activities developed in Lake Izabal’s catchment in recent years have compromised its status. This study used paleolimnological techniques to link past and recent anthropogenic activities such as mining operations and recent tilapia aquaculture. Relative abundances and concentrations of Pb, …

Modification Of The Optical Response Of Alpha Quartz Via The Deposition Of Gold Nanoparticles In Etched Ion Tracks, Maria C. Garcia Toro

Doctoral Dissertations

”This study addresses the experimental methods used to develop and characterize plasmonic devices capable of modifying the optical response of alpha quartz via the deposition of gold nanoparticles in etched ion tracks. In the first part of the research, the microstructural characterization of latent and etched ion tracks produced in alpha quartz (α-SiO₂) is presented. Single crystals of α-SiO₂ were irradiated with two highly energetic ions to different nominal fluences. As expected, the morphology of the resulting ion tracks depends on the energy of the incident ion and their stopping powers within the target material. Subsequent chemical …

Removal Of Non-Metallic Inclusions From Molten Steel By Ceramic Foam Filtration, Soumava Chakraborty

Doctoral Dissertations

”Ceramic filters are routinely used in steel foundries to remove non-metallic inclusions from steel melt. Removal efficiency for both solid and liquid inclusions by magnesia-stabilized zirconia foam filters (10ppi) were evaluated and distribution of the captured inclusions through the filter thickness was also investigated. A mold design was developed using a commercial computational fluid dynamics software package to produce two castings that fill simultaneously, one with a filter and the other without a filter, from a single ladle pour, while also matching the fill rates and avoid turbulence and reoxidation during pouring. An industrial-scale experiment was also performed to investigate …

Studying The Effects Of Various Process Parameters On Early Age Hydration Of Single- And Multi-Phase Cementitious Systems, Rachel Cook

Doctoral Dissertations

”The hydration of multi-phase ordinary Portland cement (OPC) and its pure phase derivatives, such as tricalcium silicate (C₃S) and belite (ß-C₂S), are studied in the context varying process parameters -- for instance, variable water content, water activity, superplasticizer structure and dose, and mineral additive type and particle size. These parameters are studied by means of physical experiments and numerical/computational techniques, such as: thermodynamic estimations; numerical kinetic-based modelling; and artificial intelligence techniques like machine learning (ML) models. In the past decade, numerical kinetic modeling has greatly improved in terms of fitting experimental, isothermal calorimetry to kinetic-based modelling …

Tools To Evaluate Nanodiamond-Mediated Delivery Of Tiopronin For Cataract Prevention, Justin Beltz

Doctoral Dissertations

”There is a growing demand for non-surgical means of cataract treatment. This dissertation presents three bodies of work that reflect the early-stage development of eye drop formulations aimed at delaying cataract progression. These formulations consist of the antioxidant 2-mercaptopropionylglycine (MPG) loaded onto nanodiamond particles.

Cataractogenesis is linked to oxidative damage to lens proteins. To investigate the potential of MPG for protection against oxidative damage, A549 cells were incubated in 0.6 mM tert-butylhydroperoxide (tBHP). Cells exposed to tBHP without MPG exhibited elevated levels of reactive oxygen species, which led to the depletion of the vital antioxidant glutathione and, ultimately, apoptosis. Co-administration …

Fully Differential Study Of Higher-Order Contributions To The Few-Body Dynamics Of Simple Atomic Systems, Madhav Dhital

Doctoral Dissertations

”Advancing our understanding of the few-body dynamics in simple atomic systems is one of the most important goals of atomic scattering research. In perturbation theory, this goal entails accurately describing the relative contributions from first versus higher-order mechanisms. One higher-order mechanism that is particularly important for target ionization by a charged-particle impact is known as post-collision interaction (PCI). There, the projectile and the ejected electron interact with each other at least twice. In the first interaction, the projectile transfers sufficient energy for the electron to be lifted to the continuum. The second interaction occurs in the outgoing part of the …

Critical Success Factors And Risk Mitigation Strategy For New Product Development, Rodney A. Ewing

Doctoral Dissertations

”Success in new product development (NPD) offers a competitive and comparative advantage in the marketplace. A primary objective in an NPD project is to launch world class products with minimal risk. To deliver the superior quality and performance customers require, a company must develop the right NPD structure and framework for seamless execution by the NPD project teams throughout the product lifecycle. Companies must understand how to identify and mitigate risk to enable the success of their NPD projects. The costs to develop new products are often a considerable portion of an organization’s budget; however, studies have shown only 60 …

Predictive Geohazard Mapping Using Lidar And Satellite Imagery In Missouri And Oklahoma, Usa, Olufeyisayo B. Ososami

Doctoral Dissertations

”Light Detection and Ranging (LiDAR) and satellite imagery have become the most utilized remote sensing technologies for compiling inventories of surficial geologic conditions. Point cloud data obtained from multi-spectral remote sensing methods provide a detailed characterization of the surface features, in particular, the detailed surface manifestations of underlying geologic structures. When combined, point clouds eliminate bias from visual inconsistencies and/or statistical values. This research explores the competence of point clouds derived from LiDAR and Unmanned Aerial Systems (UAS) as a predictive tool in evaluating various geohazards. It combines these data sets with other remote sensing techniques to evaluate the sensitivity …

Development Of Lightweight Materials By Meso- And Microstructure Control, Myranda Shea Spratt

Doctoral Dissertations

”In this work, two lightweight structures – lattice structures and metal matrix syntactic foams (MMSF) – were studied. Honeycomb lattices were manufactured by powder bed selective laser melting (SLM) from 304L stainless steel. The wall thicknesses of these structures ranged from 0.2 to 0.5 mm. Surface roughness was the primary cause of dimensional mismatch between the expected and as-built structures with an average wall thickness increase of 0.12 mm. The strength of the honeycombs increased with increasing wall thickness. A feature of the SLM microstructure, the melt pool boundary, was also studied as a part of this work. 3D models …

Characterization Of Reduced Graphene Oxide Anode For Application In Algae Biophotovoltaic Platforms, Siti Aisyah Ibrahim

Student Works (2020-2029)

Research interest in recent times has placed much focus on electrode technology for biophotovoltaics (BPV) especially in algal fuel cells (AFCs) application. The purpose of this investigation is therefore directed towards optimizing reduced graphene oxide (rGO) thin film as an electrode for AFCs application by means of annealing and plasma treatment. First stage involves deposition of six (6) layers of rGO thin film using Langmuir-Blodgett (LB) method. The anode electrodes were then annealed at different temperatures under vacuum condition. For plasma treatment meanwhile, a variation of voltage was used to vary the plasma conditions resulting in different surface morphology. To …

Ionic Liquid Functionalized Β-Cyclodextrin Modified Electrode As Electrochemical Sensor For 2,4-Dichlorophenol, Fairuz Liyana Mohd Rasdi

Student Works (2020-2029)

This thesis described the synthesis and characterization of ionic liquid monofunctionalized β-cyclodextrin (β-CD-1-BIMOTs) and ionic liquid difunctionalized β-cyclodextrin (β-CD-2-BIMOTs) for sensor applications. The physical characterizations of these compounds have been conducted using nuclear magnetic resonance (NMR), Fourier transform infra-red (FTIR), energy dispersive x-ray (EDX), x-ray diffraction (XRD) and Brunauer-Emmet-Teller (BET) analyses. These compounds were used as modifiers for carbon paste electrode (CPE). Cyclic voltammetry and chrono-amperometry methods were employed to examine the electrochemical responses of all prepared CPEs. All prepared electrodes show responses towards the target analyte of 2,4-dichlorophenol (2,4-DCP). Both β-CD-1-BIMOTs/CPE and β-CD-2-BIMOTs/CPE give higher current (i) responses compared …

Synthesis And Characterization Of Hybrid Organic Coating System To Reduce Thermal Degradation Of Solar Cells, Mohd Zaini Farah Khaleda

Student Works (2020-2029)

Thermal-decreasing hybrid organic coatings were developed for crystalline solar cells by using two types of binder systems; namely Aminopropyltriethoxysolution (APTES) / Methyltrimethoxysilane (MTMS) binder system (labelled as B1) and Methyltrimethoxysilane (MTMS) / nitric acid (HNO3) binder system (labelled as B2). Three types of nanoparticles; Titanium dioxide, TiO2 (Anatase), Zinc oxide, ZnO and Tin dioxide, SnO2 nanoparticles with different weight percentage were introduced inside each binder system namely; 20 wt%, TiO2 (T1B1 coating), 60 wt% TiO2 (T2B1 coating), 20 wt% ZnO (Z1B1 coating), 60 wt% ZnO (T2B1 coating), 20 wt% SnO2 (S1B1 coating) and 60 wt% SnO2 (S2B1 coating) for B1 …

2020 Fall Commencement, Georgia Southern University

Commencement Programs

No abstract provided.

Cagniard-Dehoop Technique-Based Computation Of Retarded Partial Coefficients: The Coplanar Case, Martin Stumpf, Giulio Antonini, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

Efficient computation of partial elements plays a key role in the Partial Element Equivalent Circuit (PEEC) method. A novel analytical method for computing retarded partial coefficients based on the Cagniard-DeHoop (CdH) technique is proposed. The methodology is first theoretically developed and then illustrated on the computation of a surface retarded partial coefficient pertaining to two coplanar rectangular surface elements. An efficient way for incorporating loss mechanisms in the time domain (TD) via the Schouten-Van der Pol theorem is proposed. Illustrative numerical examples demonstrating the validity of the introduced solution are given.

Off-Policy Q-Learning For Anti-Interference Control Of Multi-Player Systems, Jinna Li, Zhenfei Xiao, Tianyou Chai, Frank L. Lewis, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

This paper develops a novel off-policy game Q-learning algorithm to solve the anti-interference control problem for discrete-time linear multi-player systems using only data without requiring system matrices to be known. The primary contribution of this paper lies in that the Q-learning strategy employed in the proposed algorithm is implemented in an off-policy policy iteration approach other than on-policy learning due to the well-known advantages of off-policy Q-learning over on-policy Q-learning. All of the players work hard together for the goal of minimizing their common performance index meanwhile defeating the disturbance that tries to maximize the specific performance index, and finally …

Business Process Specification, Verification, And Deployment In A Mono-Cloud, Multi-Edge Context, Saoussen Cheikhrouhou, Slim Kallel, Ikbel Guidara, Zakaria Maamar

All Works

© 2020, ComSIS Consortium. All rights reserved. Despite the prevalence of cloud and edge computing, ensuring the satisfaction of time-constrained business processes, remains challenging. Indeed, some cloud/edge-based resources might not be available when needed leading to delaying the execution of these processes’ tasks and/or the transfer of these processes’ data. This paper presents an approach for specifying, verifying, and deploying time-constrained business processes in a mono-cloud, multi-edge context. First, the specification and verification of processes happen at design-time and run-time to ensure that these processes’ tasks and data are continuously placed in a way that would mitigate the violation of …

Decoupled Finite Element Methods For General Steady Two-Dimensional Boussinesq Equations, Lioba Boveleth

Masters Theses

"This work presents two kinds of decoupled finite element methods for the steady natural convection problem in two dimensions. Firstly, the standard Galerkin finite element method is derived in detail stating algorithms needed for the realization in MATLAB. A numerical example verifies the error convergence. Secondly, using iteration, the Boussinesq equations are decoupled into the Navier-Stokes equations and a parabolic problem. The resulting problems are solved either in parallel or sequentially. Finally, the same numerical example as before is used to confirm the convergence and analyze the methods in terms of iteration performance. In addition to a higher flexibility and …

Shock Wave Propagation Behavior At Corners And Crosscuts In Five Small-Scale Tunnel Scenarios, David Pierre Doucet

Masters Theses

"Shock wave propagation in tunnels and other enclosed environments is substantially more complicated than in an open-air or even a surface detonation. There is still much to learn about how shock wave properties change as a wave propagates in an enclosed space, such as a mine tunnel, inside of a building, or city street. The geometry of the enclosure will have a large role in the propagation of the shock wave. This means that many different tunnel designs must be studied. This work tested five different designs using a modular small-scale model. The scenarios tested were Straight-line, Single Turn, Around …

Attack Detection And Mitigation In Mobile Robot Formations, Arnold Fernandes

Masters Theses

"A formation of cheap and agile robots can be deployed for space, mining, patrolling, search and rescue applications due to reduced system and mission cost, redundancy, improved system accuracy, reconfigurability, and structural flexibility. However, the performance of the formation can be altered by an adversary. Therefore, this thesis investigates the effect of adversarial inputs or attacks on a nonholonomic leader-follower-based robot formation and introduces novel detection and mitigation schemes.

First, an observer is designed for each robot in the formation in order to estimate its state vector and to compute the control law. Based on the healthy operation of the …

Design And Development Of Power Processing Units For Applications In Electrically-Propelled Satellite Systems, Kartikeya Jayadurga Prasad Veeramraju

Masters Theses

"Electrospray technology provides a way to ionize specialized liquids by applying high voltages across a sharp porous tip and a metallic mesh. This technology is widely used in the field of mass spectroscopy for generating ions for testing purposes. The dawn of nano-satellites posed new challenges in the miniaturization of many conventional satellite sub-systems. One significant challenge faced in such a process was the miniaturization of the propulsion system. Electrosprays have started to find their application in the field of Aerospace Engineering and now are formally known as Electrospray Thrusters. These thrusters provide high specific impulse and are attractive substitutes …

On Predicting Stopping Time Of Human Sequential Decision-Making Using Discounted Satisficing Heuristic, Mounica Devaguptapu

Masters Theses

“Human sequential decision-making involves two essential questions: (i) "what to choose next?", and (ii) "when to stop?". Assuming that the human agents choose an alternative according to their preference order, our goal is to model and learn how human agents choose their stopping time while making sequential decisions. In contrary to traditional assumptions in the literature regarding how humans exhibit satisficing behavior on instantaneous utilities, we assume that humans employ a discounted satisficing heuristic to compute their stopping time, i.e., the human agent stops working if the total accumulated utility goes beyond a dynamic threshold that gets discounted with time. …

Computer Vision Based Deep Learning Models For Cyber Physical Systems, Muhammad Monjurul Karim

Masters Theses

“Cyber-Physical Systems (CPSs) are complex systems that integrate physical systems with their counterpart cyber components to form a close loop solution. Due to the ability of deep learning in providing sensor data-based models for analyzing physical systems, it has received increased interest in the CPS community in recent years. However, developing vision data-based deep learning models for CPSs remains critical since the models heavily rely on intensive, tedious efforts of humans to annotate training data. Besides, most of the models have a high tradeoff between quality and computational cost. This research studies deep learning algorithms to achieve affordable and upgradable …

Determining Variable Depth To Bedrock Using Ert And Masw: A Geophysical Investigation In St. Louis, Mo, Justin James Clinton

Masters Theses

“The research involves a geophysical study in the Maremec River Valley in St. Louis County, Missouri. The geophysical methods described in this paper can provide a relatively quick, inexpensive, and accurate means in investigating the lithologic characteristics of the subsurface. Method selection is ultimately dependent of the type of investigation and site-specific characteristics. In this investigation, Electrical Resistivity Tomography (ERT) data and Mutli-Channel Analysis of Surface Waves (MASW) data were acquired to image the bedrock beneath the Maremec River to an approximate depth of 110 ft or an elevation of 300 ft for a proposed wastewater tunnel. Two overlapping dipole-dipole …

Aquatic Plants And Their Application To Successful Floating Treatment Wetlands, Katherine May Mazanec

Masters Theses

“This research aims to mitigate eutrophication of freshwater habitats affected by urban stormwater runoff. Two highly impacted urban ponds near the Missouri S&T campus in Rolla were the focus of this research on the application of floating treatment wetlands (FTWs). An FTW consists of a man-made floating mat that is planted with emergent or floating macrophytes. The plants grow on the mat and their roots extend into the water column below the mat. Plant tissues, especially roots in direct contact with the water, take up nutrients, act as biofilm growth sites, and may facilitate precipitation of nutrients. With urbanization, ponds …

The Role Of Tectonic Inheritance, Plate-Reorganization, And Magma Flare-Ups In The Evolution Of The Sevier Orogeny, J. Daniel Quick

Masters Theses

"The temporal and spatial distribution of strain associated with the Sevier Orogeny in western North America is significantly different in the southern end of the belt, at the latitude of Las Vegas, than further to the north at the latitude of Salt Lake City. Until this study, reasons for these differences were speculative as a lack of thrust kinematic data in the intervening region hindered along strike correlation across the belt. A crystallization age of 100.18 ± 14 0.04 Ma was determined for zircons extracted from a recently recognized ash fall tuff near the base of the synorogenic Iron Springs …

Evaluation Of The Symbiotic Relation Between Endophyte And Poplar Trees Exposed To Landfill Leachate, Catalina Vega Hurtado

Masters Theses

“The contamination of soil and groundwater from leachate leakage from landfill has turned, nowadays, into a global public issue. One of the main concerns about this pollutant is the potential threat to human and ecosystem health. The current research studied endophyte bacteria in association with poplar trees (Populus sp.), as a method of bioremediation of landfill leachates. The objective of the project was to identify treatment strategies that may improve plant performance (survival rates, plant fitness, and degradation efficacy) with the purpose of being implemented in phytoremediation plots, aimed to intercept and treat landfill leachate, before the contamination of watershed. …

Contextual Healing: Privacy Through Interpretation Management, Fatma Outay, Rula Sayaf

All Works

Contextual privacy is an essential concept in social software communication. Managing privacy of data disclosed in social software dependence strongly on the context the data is disclosed in. The sheer amount of posts and audiences may lead to context ambiguity. Ambiguity can affect contextual privacy management and effective communication. Current contextual privacy management approaches can be either too complex to use, or too simple to offer fine-grained control. In many cases, it is challenging to strike a balance between effective control and ease-of-use. In this article, we analyse contextual privacy by in relation to context and communication. We examine a …

Combining Laser Aided Ablation And Polishing To Minimize Surface Roughness Of Additively Manufactured Aluminium Components, Sahil Bipinkumar Patel

Masters Theses

“The surface roughness of additively manufactured parts is much higher than the acceptable range for most applications, thus post-processing is needed to qualify these parts for use. Laser polishing can be used to bring the surface roughness in an admissible range, but if the initial roughness is very high then the energy density for the polishing process needs to be very high to achieve a significant reduction in roughness. This high energy density can produce many process defects. Also, laser polishing alone cannot get rid of high wavelength asperities. Any waviness in the part can be linked with initial waviness …