Engineering Commons^™

Hydrological And Water Quality Assessment Of Forested Coastal Watersheds, Shreeya Bhattarai

Theses and Dissertations

Coastal regions are at risk of environmental threats. Flooding in coastal rivers is the result of intense precipitation which is triggered by climate change. Coastal watersheds are prone to losing significant amounts of sediment and nutrients because of the shorter transport pathway that drains directly into the coastal water. In this study, the hydrology, flood frequency, and water quality assessment of two coastal watersheds, Wolf River watershed (WRW) and Jourdan River watershed (JRW), were conducted using the Soil and Water Assessment Tool (SWAT). Since WRW and JRW are the main tributaries to fetch freshwater to Saint Louis Bay (SLB) of …

Secure And Efficient Federated Learning, Xingyu Li

Theses and Dissertations

In the past 10 years, the growth of machine learning technology has been significant, largely due to the availability of large datasets for training. However, gathering a sufficient amount of data on a central server can be challenging. Additionally, with the rise of mobile networking and the large amounts of data generated by IoT devices, privacy and security issues have become a concern, resulting in government regulations such as GDPR, HIPAA, CCPA, and ADPPA. Under these circumstances, traditional centralized machine learning methods face a problem in that sensitive data must be kept locally for privacy reasons, making it difficult to …

Aggregate Characteristics For Unpaved Highway Shoulders, Jessica V. Lewis

Theses and Dissertations

This thesis studied unpaved highway shoulders, and in particular shoulders of lower volume asphalt pavements being overlaid. The primary objective was to better understand how different shoulder aggregates perform on lower volume routes with asphalt surfaces and relatively narrow shoulders. A literature review and an evaluation of a full-scale test section containing five aggregate categories in nine test sections over a thirty-four-month period were the primary efforts performed to evaluate unpaved highway shoulders. The study concluded shoulder width measurements were not especially informative, and that California Bearing Ratio measurements were only modestly informative. Crushed concrete outperformed all other aggregates, though …

Managing Iron Deficiency Chlorosis (Idc) In Soybean Through A Cropping System Approach, Katelin Savannah Waldrep

Theses and Dissertations

Iron deficiency chlorosis (IDC) is a frequent problem throughout many areas of the United States where soils are high in calcium carbonate (CaCO₃), including the Blackland Prairie regions of Mississippi. The main objectives of this study were to 1) determine the effects of seven different cropping systems on IDC visual symptomology and grain yield in rainfed soybeans grown in calcareous soils, and 2) evaluate the effects of soil water tension (SWT) on IDC. Rotating soybeans with corn produced significantly higher yields for both tolerant and susceptible soybean varieties. IDC symptomology was worse, and yields were lower in cropping …

Lateral Swelling Pressure In Variably Saturated Expansive Clay, Steven Ray Garrett

Theses and Dissertations

Lateral swelling pressure induced in expansive soils upon wetting can adversely impact the performance and integrity of earthen structures and foundations. The yearly cost associated with damage to structures from expansive clays in the United States is estimated to exceed the loss associated with natural disasters such as earthquakes, floods, and hurricanes. The main objective of this dissertation is to provide new insight into the evolution of lateral swelling pressure in variably saturated expensive soils under infiltration via physical testing. In the first part of this study, a new laboratory-scale testing apparatus was built to measure lateral and vertical swelling …

Evaluation Of Early Maturing Cultivars, Optimal Harvest Timing, And Canopy Reflectance Of Peanut To Maximize Grade And Yield, Joseph Bryan Whittenton

Theses and Dissertations

Peanut digging timing is difficult to predict due to indeterminate growth and peanut pods maturing underground, resulting in the need to research methods that provide consistent measurements, while reducing time and effort for farmers and researchers. Experiments were conducted to evaluate the accuracy of the Maturity Index 1 and Maturity Index 2 in predicting peanut grade, the accuracy of the North Carolina 2 degree day method in predicting peanut yield, and remote sensing vegetative indices sensitivity equivalence (SEq) to peanut Maturity Index 2 and harvest grade (TSMK) for cultivars IPG-914 and Georgia-06G in Mississippi.

Maturity Index 1 and …

An Electric Commerce Platform For Material Testing Laboratories, John Ferris Mitchener

Theses and Dissertations

The emergence of the Internet has allowed businesses to create new sales and marketing channels to provide value for their customers in the marketplace. Engineering manufacturers and suppliers have taken advantage of the internet to automate the customer service aspects of their businesses as well as to market their services in a cost-effective but widespread manner. This work aims to apply the practices and benefits of electronic commerce (e-commerce) to a material testing laboratory through the creation of a functioning website with e-commerce features. The effects of Search Engine Optimization, website accessibility issues, marketing considerations, security concerns, and common business …

Passive Vs. Active Wearable Technology Monitoring Trunk Flexion In Elementary Teachers, Bailey Jose

Theses and Dissertations

The objective of this study was to assess the biomechanical and subjective measures of elementary school teachers while wearing active and/or passive wearable devices during the average workday. Five elementary school teachers wore a harness that held an Upright GO 2 posture tracking device and a Vicon Blue Trident sensor on the participant's upper back for two school days. Haptic feedback was on for one day and off for the other. Data from the Vicon wearable was analyzed to determine participants’ trunk flexion severity, frequency, and duration. Surveys were used to determine perceived exertion and perception of wearable technology. This …

Integrating Steel Slag Aggregates Into Asphalt Paving By Harmonizing Availability, Quality, Economics, And The Environment, Timothy R. Murphy

Theses and Dissertations

This thesis provides guidance on how to balance matters related to the environmental stewardship, market sources, origin and uses, material properties, performance, and economic impact of using slag materials in pavements. The literature on this topic provides numerous references on the use of slag materials for specific applications, and this thesis aims to make use of those references along with other data from the author to describe slag materials from a holistic perspective and provide some suggestions for balancing several factors that impact optimal use of this resource within pavement structures. Discussion is given to the increased importance of recycling …

Wildfire-Altered Geotechnical Soil Properties And Their Impact On Subsequent Landslides, James M. Kellogg

Theses and Dissertations

Wildfires result in altered landscape as well as altered soil properties. Wildfires result in conditions that are more susceptible to geotechnical hazards introducing a potential for cascading events in the surrounding area. Shallow landslides are common geohazards that result in a post-wildfire landscape. With an ever-increasing trend in wildfires, the need to better understand the impact wildfire-altered soil properties play on shallow slope instability is critical to evaluating risks to existing or planned development, mitigation of potentially hazardous conditions, prioritization of post-wildfire planning, and post-wildfire response preparation. The primary objective of this study is to provide a comprehensive overview of …

Unmanned Aerial System Integration Safety And Security Technology Ontology, Rebecca A. Garcia

Theses and Dissertations

Unmanned Aerial System (UAS) is a versatile and essential tool for law enforcement, first responders, utility providers, and the general public. Integrating the UAS into the National Airspace System (NAS) poses a significant challenge to policymakers and manufacturers. A UAS Integration Safety and Security Technology Ontology (ISSTO) has been developed in the Web Ontology Language (OWL) to aid in this integration. ISSTO is a domain ontology covering aviation topics corresponding to flights, aircraft types, manufacturers, temporal/spatial, waivers and authorizations, track data, NAS facilities, air traffic control advisories, weather phenomena, surveillance and security equipment, and events, sensor types, radio frequency ranges, …

A Generalizable Method And Case Application For Development And Use Of The Aviation Systems – Trust Survey (As-Ts)., Jamison Hicks

Theses and Dissertations

Automated systems are integral in the development of modern aircraft, especially for complex military aircraft. Pilot Trust in Automation (TIA) in these systems is vital for optimizing the pilot-vehicle interface and ensuring pilots use the systems appropriately to complete required tasks.

The objective of this research was to develop and validate a TIA scale and survey methodology to identify and mitigate trust deficiencies with automated systems for use in Army Aviation testing. There is currently no standard TIA assessment methodology for U.S. Army aviation pilots that identifies trust deficiencies and potential mitigations.

A comprehensive literature review was conducted to identify …

Advancements In Geospatial Monitoring Of Structures, Jordan Keith Baldwin

Theses and Dissertations

The need for advancements in geospatial monitoring of structures has evolved naturally as structures have become larger, more complex, and technology has continued to rapidly develop. Greater building heights generally lead to greater challenges for surveyors, limiting the practical use of traditional measurement methods. For this reason, a new complimentary method was developed and implemented to support elevation monitoring activities during construction of the Salesforce Tower in San Francisco, California. While some studies have explored the use of strain gauges to monitor strain development within individual members, the primary contribution of this work is that it presents a practical and …

Eddy Current Defect Response Analysis Using Sum Of Gaussian Methods, James William Earnest

Theses and Dissertations

This dissertation is a study of methods to automatedly detect and produce approximations of eddy current differential coil defect signatures in terms of a summed collection of Gaussian functions (SoG). Datasets consisting of varying material, defect size, inspection frequency, and coil diameter were investigated. Dimensionally reduced representations of the defect responses were obtained utilizing common existing reduction methods and novel enhancements to them utilizing SoG Representations. Efficacy of the SoG enhanced representations were studied utilizing common Machine Learning (ML) interpretable classifier designs with the SoG representations indicating significant improvement of common analysis metrics.

Developing Systems Engineering And Machine Learning Frameworks For The Improvement Of Aviation Maintenance, Fatine Elakramine

Theses and Dissertations

This dissertation develops systems engineering and machine learning models for aviation maintenance support. With the constant increase in demand for air travel, aviation organizations compete to maintain airworthy aircraft to ensure the safety of passengers. Given the importance of aircraft safety, the aviation sector constantly needs technologies to enhance the maintenance experience, ensure system safety, and limit aircraft downtime. Based on the current literature, the aviation maintenance sector still relies on outdated technologies to maintain aircraft maintenance documentation, including paper-based technical orders. Aviation maintenance documentation contains a mixture of structured and unstructured technical text, mainly inputted by operators, making them …

Physics-Based Modeling Of Post-Wildfire Landslides In Unsaturated Hillslopes, Masood Abdollahi

Theses and Dissertations

Changes in climatic regimes and land use have led to increases in wildfire activities around the world. Wildfires are now happening more frequently, at higher altitudes, and higher severities. Adverse impacts of wildfires can last years after the fire has been contained through post-fire geohazards, such as shallow landslides. Post-wildfire shallow landslides are often mobilized by rainfall and due to fire-induced changes in soil and land cover properties and near-surface processes. This study aims to develop a physics-based framework to evaluate the stability of burned hillslopes against rainfall-triggered shallow landslides. A coupled hydromechanical infiltration model is developed by employing a …

Relaxing Dc Capacitor Voltage Of Power Electronic Converters To Enhance Their Stability Margins, Ali Zakerian

Theses and Dissertations

Recently, due to the increasing adoption of distributed energy resource (DER) technologies including battery energy storage (BES) and electric vehicle (EV) systems, bidirectional power converters are becoming more popular. These converters are broadly utilized as interface devices and provide a bidirectional power flow in applications where the primary power supply can both supply and receive energy. A dc capacitor, called the dc-link, is an important component of such bidirectional converters. For a wide range of applications, the converter is required to control the dc-link voltage. Commonly, a proportional-integrating (PI) controller is used by the dc capacitor voltage controller to generate …

Thermal Atomization Of Impinging Drops On Superheated Superhydrophobic Surfaces, Eric Lee

Theses and Dissertations

Drop impact on a surface has an effect on nearly every industry and this impact may have adverse effects if not controlled. Superhydrophobic (SH) surfaces have been created with the extreme ability to repel water. These surfaces exist in nature but may also be fabricated using modern techniques. This thesis explores heat transfer from these SH surfaces to drops impacting them. This thesis is devoted to increasing the breadth of knowledge of thermal atomization during drop impingement on superheated SH surfaces. When a water drop impinges vertically on a horizontal superheated surface, intense atomization can occur. The atomization is caused …

Framework For Applicability Of Fidic Red Book (1999) For Contracts Governed By Law No. 182 Of The Year 2018 For Regulating Contracts Concluded By Public Entities, Fredy Ayad

Theses and Dissertations

An administrative contract is a type of contract that the administrative body enters in order to achieve a public interest. In Egypt, administrative contracts are governed by Law No. 182 of the year 2018 for Regulating Contracts concluded by Public Entities, which has been promulgated in October 2018. This Law includes several mandatory rules, which will govern over any conditions in the construction contract.

The FIDIC Red Book 1999 is widely used in Egypt and the Middle East in private sector and is currently also being utilized by governmental bodies. However, some contractors are not aware of the major deviations …

An Incremental Based Approach For 3d Multi-Angle Point Cloud Stitching Using Icp And Knn, Pankti K. Patel

Theses and Dissertations

The basic principle of stitching is joining or merging any two materials or objects. 3D point cloud stitching is basically stitching two 3D point cloud together. 3D point cloud stitching is an emerging topic and there are multiple ways to achieve it. There are various methods for stitching which all have changes throughout the time. The existing methods do have shortcomings and have ignored the multiangle stitching of a same model or an object. This shortfall leads to many deficiencies in the ability of a stitching algorithm to maintain accuracy over the period. In this work I have introduced a …

Modeling The Impact Of Scheduling Risks On Multi-Team Agile Projects, Bria Marie Booth

Theses and Dissertations

Agile project management allows for a quick response to a changing project environment. This opens possible avenues for new opportunities, but also may expose ongoing projects to previously unknown or unexpected threats. Risks must be continuously monitored as a product is worked on to avoid lost potential. This paper will propose a discrete event simulation model that multi-team projects may use to predict the impact to the project’s schedule. Using discrete event simulation early in the project’s planning cycle offers a greater understanding of the possible or probable impact of risks on the schedule. This would help to prepare project …

Evaluation Of Human Mobility From Crowd-Sourced Cellular Data, Sasa Knezevic

Theses and Dissertations

Understanding patterns of human mobility plays a vital role in urban planning, traffic management, disease control, environmental impact evaluation, provisioning of services by both public and private enterprise and other areas of human activity. In this thesis, the human mobility patterns are studied using crowd sourced cellular data. The study characterizes human mobility through a meaningful set of mobility parameters. Each parameter is clearly defined, extracted from the available data, and described using statistical modeling tools. The parameters are evaluated at different time scales. It has been determined that despite its apparent randomness on the individual level, human mobility on …

Cross-Platform Development Of Wake-Up-Word, Christopher Ryan Woodle

Theses and Dissertations

The goal of this project will be to explore cross-platform implementation of Wake-Up- Word (WUW). To enable the development of future speech-based artificial intelligence applications, it is important to have robust and accessible implementations of WUW. Adoption of Unix based operating systems continues to expand for server, backend, and embedded applications, therefore a WUW implementation in Unix will become essential. As web technologies continue to grow, WUW will also need to be implemented in web, using technologies such as JavaScript and Web Assembly (WASM). This project encompasses porting the previous implementation of WUW from Microsoft Windows to Unix, building a …

Xeno-Free Biomimetic Ecm Model For Investigation Of Matrix Properties On Astrocyte Cell Response, Bayan Saleh

Theses and Dissertations

Astrocytes are crucial in preserving the structural and functional integrity of the central nervous system (CNS). They participate in several physiological processes, such as the uptake of neurotransmitters, control of extracellular ion concentration, and preservation of the blood-brain barrier. Recent research has raised the possibility that astrocytes are also involved in the onset and development of Alzheimer's disease (AD). While the precise mechanisms underlying the development and progression of AD are not fully understood, recent research has suggested that age-related changes in the brain extracellular matrix (ECM) properties may play a critical role in the progression of the disease. Investigating …

Using Actor-Critic Reinforcement Learning For Control Of A Quadrotor Dynamics, Edgar Adrian Torres

Theses and Dissertations

This paper presents a quadrotor controller using reinforcement learning to generate near-optimal control signals. Two actor-critic algorithms are trained to control quadrotor dynamics. The dynamics are further simplified using small angle approximation. The actor-critic algorithm’s control policy is derived from Bellman’s equation providing a sufficient condition to optimality. Additionally, a smoother converter is implemented into the trajectory providing more reliable results. This paper provides derivations to the quadrotor’s dynamics and explains the control using the actor-critic algorithm. The results and simulations are compared to solutions from a commercial, optimal control solver, called DIDO.

Smartphone Video Guidance Sensor In High-Altitude Uav Precision Landing, Joao Leonardo Silva Cotta

Theses and Dissertations

The Smartphone Video Guidance Sensor (SVGS) is an emerging technology developed by NASA Marshall Space Flight Center that uses a vision-based approach to accurately estimate the six-state position and orientation vectors of an illuminated target of known dimensions with respect to a coordinate frame fixed to the camera. SVGS is a software-based sensor that can be deployed using a host platform’s resources (CPU and camera) for proximity operations and formation flight of drones or spacecraft. The SVGS output is calculated based on photogrammetric analysis of the light blobs in each image; its accuracy in linear and angular motion at different …

Development Of Design Method For Fiber Reinforced Slab On Ground, Abdullah Albogami

Theses and Dissertations

All the present methods of designing the slab-on-ground (SOG) are based on the flexural slab capacity (FSC) to determine the required thickness by calculating the modulus of rupture (MOR) of the concrete beam, depending on ASTM C78 or AASHTO T 97 specifications. All previous experimental results have confirmed that the MOR is much lower than the FSC and it cannot be used to predict FSC accurately. Hence, using the MOR to predict the FSC would lead to the underestimation of FSC and require more unnecessary thickness. Therefore, this study aims to develop accurate equation for estimating the FSC based on …

Electrical Characterization Of Cementitious Composites, Abbas Ali

Theses and Dissertations

Multifunctional concrete using electrical conductivity gains attention for various nonstructural applications. Particularly, conductive concrete enables monitoring internal damages in concrete, which has been impossible by conventional nondestructive methods. On the other hand, most of on-going investigations on multifunctional concrete uses conductive additives to impart electrical conductivity into concrete, but this limits the multifunctional application to predesigned structures. Finding multifunctionality embedded in conventional concrete can open various possibilities for smart concrete. Aiming to finding the feasibility of using conventional concrete for multifunctional application, this study investigates the electrical properties of plain cementitious composites including cement paste, mortar, and concrete, but not …

Characterization Of Lower Rio Grande Valley Watershed, Abdulkabir O. Aduragba

Theses and Dissertations

The Lower Laguna Madre (LLM) is considered impaired because of the high concentration of bacteria and low level of dissolved oxygen (DO). LLM receives freshwater from the Lower Rio Grande Valley (LRGV) watershed. In other to understand the impairment, LRGV watershed is being studied by relying on water quality data of the contributing drainages and State resource geographic data to identify watershed boundary and pollutant sources.

The study on the North and Central LRGV watershed shows some correlation between the concentration of E. coli/Bacteria, Ammonia, Total Kjeldahl Nitrogen, Total Phosphorus, Nitrate and Nitrite, Chlorophyll-a and the sources of pollutant in …

Formation Control Of Multiple Quadrotors, Miguel Alejandro Garcia

Theses and Dissertations

This thesis studies formation control of multiple quadrotors under different conditions. Two controller design approaches are proposed. In the first approach, it is assumed that the dynamics of each quadrotor is unknown and there is disturbance. With the aid of distributed estimation and the universal approximation property of neural networks, distributed tracking controllers are proposed. Simulation shows the effectiveness of the proposed controllers. In the second approach, it is assumed that the inertia parameters are unknown. With the aid of distributed estimation, online data estimation, and optimal control theory, distributed sub-optimal tracking controllers are proposed. Simulation results show the effectiveness …