Engineering Commons^™

Multi-Robot Path Planning Using Sampling-Based Algorithms And Reinforcement Learning, Donald J. Alexander

Master's Theses

In today’s world, robots are becoming extremely useful in many facets of life. With the recent increase in applicable uses of robots, multi-robot path planning has emerged as a fundamental research area. Multi-robot path planning is the process of developing a coordinated plan which is utilized by multiple robots to efficiently work together to complete a common goal. Over the history of multi-robot path planning, many new path planning methodologies have been developed with the goal of outperforming the last, boasting better efficiency and optimality. In this thesis, an analysis of various multi-robot path planning methodologies is carried out with …

Monitoring The Land Cover Changes In Mangrove Areas And Urbanization Using Normalized Difference Vegetation Index And Normalized Difference Built-Up Index In Krabi Estuary Wetland, Krabi Province, Thailand, Katawut Waiyasusri

Applied Environmental Research

Krabi Estuary Wetland (KEW) is an outstanding wetland with an estuary environment. At present, the tourism industry has rapidly grown, resulting in the impact of land cover changes. This research aims to assess the changes that have occurred in the KEW from 1999 to 2020 using NDVI and NDBI for monitoring changes in mangrove areas and urbanization in Krabi Province, Thailand. Landsat satellite images in years 1999, 2009 and 2020 were classified by using a band ratio to create land cover maps. The results show that NDVI between 0.41–1.00 clearly shows the mangrove forest area, while NDBI between 0.01–0.40 shows …

Application Of Gis And Multi-Criteria Statistical Techniques In Assessing Water Quality In The Coastal Province Of Vietnamese Mekong Delta, Giao Thanh Nguyen, Thi Hong Nhien Huynh

Applied Environmental Research

The study was conducted to evaluate the quality and spatial distribution of surface water quality in Soc Trang, a coastal province using Geographic information system (GIS) and multivariate statistical analysis. Water monitoring data was collected from 19 sampling locations with 19 parameters were analyzed from February 2019 to August 2020. The results indicated that water quality was contaminated with organic matters, nutrients, coliforms and salinity. Water quality index (WQI=22–73) indicated that water quality was from poor to medium level. Cluster analysis (CA) classified 19 monitoring sites into 7 groups and 19 months into 3 seasons including rainy season, rainy season-early …

Adsorption Of Methylene Blue By Low-Cost Biochar Derived From Elephant Dung, Yanasinee Suma, Nittaya Pasukphun, Numfon Eaktasang

Applied Environmental Research

Elephant dung biochar (ED350) prepared by controlled heating at 350 ºC was used to adsorb methylene blue (MB) in an aqueous solution. The effects of adsorption time, pH, adsorbent dosage, and initial MB concentration were examined. Kinetic, isotherm, and thermo-dynamic models were then further analyzed to determine the adsorption. The results show that ED350 was found to be efficient within 180 min. The optimum pH of MB adsorption was 11. The Langmuir isotherm model was found to be the most suitable fit for the adsorption equilibrium data, with ED350 having a homogeneous surface. The calculated equilibrium parameter (RL) …

A Workforce And Truck Allocation Model In A Solid Waste Management System: A Case From Nigeria, Desmond E. Ighravwe, Sunday A. Oke

Applied Environmental Research

No abstract provided.

Spatiotemporal Flood Risk Determination And Management For A Large River Basin, Nuanchan Singkran

Applied Environmental Research

No abstract provided.

Synergistic Effect Of Waste Feedstock Mixture And Torrefaction Pre-Treatment On Some Briquette Characteristics Of Cornhusk And Sawdust Wastes, Mufutau A. Waheed, Opeyemi A. Akogun

Applied Environmental Research

Agricultural waste management through energy recovery is one of the critical options that could drive the clean energy production industry and properly replace the use of coal in Nigeria if done sustainably. The objective of this work therefore is to study the synergetic effect of waste feedstock mixture and torrefaction pre-treatment on some physical and performance characteristics of briquettes from cornhusk (CH) and sawdust (SD) wastes. In this work, CH and SD wastes were processed raw and torrefied at 200 to 300 °C and were mixed in the ratios between 90/10 and 10/90 for briquette production using D-optimal crossed design. …

Event-Triggered Control Architectures For Scheduling Information Exchange In Uncertain And Multiagent Systems, Stefan Ristevski

USF Tampa Graduate Theses and Dissertations

Despite the numerous advantages that networked controlled systems provide, potential network overload in these systems can severely degrade their performance and even cause catastrophic failures. To this end, the work presented in this dissertation provides a neat solution on reducing network utilization in uncertain networked controlled systems using an adaptive event-triggered control approach predicated on a novel dynamical threshold and information exchange methodology while guaranteeing closed-loop system stability.

In particular, consider a system consisting of an operator (e.g, a ground station) and an uncertain controlled dynamical system (e.g., a vehicle equipped with feedback control algorithm), where the aim of the …

Interrelation Of Thermal Stimulation With Haptic Perception, Emotion, And Memory, Mehdi Hojatmadani

USF Tampa Graduate Theses and Dissertations

Haptics is an interdisciplinary field of science that deals with how humans perceive and respond to different sensory cues perceived through touch. Thermal haptics as a branch deals with how humans perceive the temperature sensation and respond to that. The process in which thermal perception occurs is well known to researchers. What seems missing in the literature is how temperature interacts or sometimes intervenes in other physiological and psychological aspects of our lives. In this research, a series of studies are presented where the main focus was how temperature and brain interact with each other to impede or enhance our …

Assessment Of Heat-Affected Zone Softening Of Hot-Press-Formed Steel Over 2.0 Gpa Tensile Strength With Bead-On-Plate Laser Welding, Kwangsoo Kim, Namhyun Kang, Minjung Kang, Cheolhee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

High-strength hot-press-formed (HPF) steels with a fully martensitic microstructure are being widely used in the fabrication of automotive body structure, and 2.0 GPa-strength HPF steel has recently been commercially launched. However, heat-affected zone (HAZ) softening is unavoidable in welding martensitic steel. In this study, the HAZ softening characteristic of 2.0 GPa HPF steel was investigated by applying a high-brightness laser welding process, wherein the heat input was controlled by varying the welding speed. Microstructural evaluation and hardness test results showed that the base metal with a fully martensitic microstructure was changed to the same type of fully martensitic microstructure in …

Anatomical Correlates Of Age-Related Basal Forebrain Dysfunction, Brandy Lynn Somera

Theses and Dissertations

The basal forebrain (BF) is comprised of several nuclei including the substantia innominata, medial septum, nucleus basalis and diagonal band of broca which are involved in cognitive functions including attention, motivation, and arousal. BF neurons are particularly vulnerable to dysfunction and degeneration in aged humans and, more dramatically, in diseases such as Alzheimer's disease (AD). Age-related BF dysfunction may reflect diminished afferent regulation as well as an altered local glial environment. Our lab has previously shown reduced orexin/hypocretin innervation of BF in aging, a phenomenon that may link afferent dysfunction with altered microglial homeostasis. There is little research examining these …

Simulation-Based And Data-Driven Approaches To Industrial Digital Twinning Towards Autonomous Smart Manufacturing Systems, Kaishu Xia

Theses and Dissertations

A manufacturing paradigm shift from conventional control pyramids to decentralized, service-oriented, and cyber-physical systems (CPSs) is taking place in today’s Industry 4.0 revolution. Generally accepted roles and implementation recipes of cyber systems are expected to be standardized in the future of manufacturing industry. Developing affordable and customizable cyber-physical production system (CPPS) and digital twin implementations infuses new vitality for current Industry 4.0 and Smart Manufacturing initiatives. Specially, Smart Manufacturing systems are currently looking for methods to connect factories to control processes in a more dynamic and open environment by filling the gaps between virtual and physical systems.

The work presented …

An Investigation Of Strong Electrostatic Adsorption Using Formed Commercial Supports, Connor Brendan Mcdonough

Theses and Dissertations

Strong electrostatic adsorption (SEA) is a well-tested procedure for the synthesis of supported monometallic and bimetallic nanoparticles with ultrasmall size (< 2 nm). Where, previous studies have laid the foundation for SEA using a variety of powdered supports, catalysts in this form are not suited for large volume chemical applications where pressure drop is critical to the process economics. Although there is no fundamental difference between the surface functional groups on powdered and extruded supports, the present study examined electrostatic adsorption as it relates to proton diffusion, precursor diffusion, and capillary imbibition.

Three formed alumina spheres and one carbon extrudate were selected for study. The alumina spheres, provided by BASF, were developmental materials with varying pore size distributions between 12 and 24800 angstroms. The carbon, provided by ADM and manufactured by CABOT, was strictly microporous in structure and was included to investigate the differences in mass transport as a function of support material.

Results indicated, a significant limitation in the approach to pH equilibrium comparing formed alumina spheres with the same …

Printing Quality Improvement For Laser-Induced Forward Transfer Bioprinting: Numerical Modeling And Experimental Validation, Jie Qu, Chaoran Dou, Ben Xu, Jianzhi Li, Zhonghao Rao, Andrew Tsin

Manufacturing & Industrial Engineering Faculty Publications

Laser-induced-forward-transfer (LIFT)-based laser assisted bioprinting (LAB) has great advantages over other three-dimensional (3D) bioprinting techniques, such as none-contact, free of clogging, high precision, and good compatibility. In a typical LIFT based LAB process, a jet flow transfers the bioink from the ribbon to the substrate due to bioink bubble generation and collapse, and the printing quality is highly dependent on the jet flow regime (stable or unstable), so it is a great challenge to understand the connection between the jet flow and the printing outcomes. To tackle this challenge, a novel computational-fluid-dynamics (CFD)-based model was developed in this study to …

An Analysis Of The Factors Affecting Attitudes Toward Drone Delivery And The Moderating Effect Of Covid-19, Jeremy A. Frazier

Doctoral Dissertations and Master's Theses

This research explored the factors affecting attitudes toward drone delivery and the moderating effect of COVID-19. Government effort to address the COVID-19 pandemic has led to social distancing and shelter-in-place guidelines. Many states have imposed additional regulations, restricting retailers from offering in-store shopping and restaurants from offering indoor dining. As a result, the use of delivery services has increased. In a further effort to reduce virus spread, some delivery services now offer a contact-free option. The contact-free option permits orders to be left at a designated location, eliminating the physical-human interaction upon delivery. The contact-free nature and potential speed of …

Additively Manufactured Dielectric Elastomer Actuators: Development And Performance Enhancement, Stanislav Sikulskyi

Doctoral Dissertations and Master's Theses

The recently emerging and actively growing areas of soft robotics and morphing structures promise endless opportunities in a wide range of engineering fields, including biomedical, industrial, and aerospace. Soft actuators and sensors are essential components of any soft robot or morphing structure. Among the utilized materials, dielectric elastomers (DEs) are intrinsically compliant, high energy density polymers with fast and reversible electromechanical response. Additionally, the electrically driven work principle allows DEs to be distributed in a desired fashion and function locally with minimum interference. Thus, a great effort is being made towards utilizing additive manufacturing (AM) technologies to fully realize the …

Developing A Lab-Scale Fluidized Bed Dryer System To Enhance Rough Rice Drying Process, Kaushik Luthra

Graduate Theses and Dissertations

For more than half of the world's population, rice (Oryza sativa L.) is a staple meal. However, rice growers encounter difficulties supplying this demand, particularly in developing nations, where rice is susceptible to spoilage if the moisture content is not lowered to a safe level soon after harvest. As a result, traditional drying methods, such as sun drying and natural air drying, are commonly used by rice growers, particularly in underdeveloped nations. However, these procedures are time-consuming and can lead to rice spoilage. On the other hand, fluidized bed drying is a well-established technology that might give rice growers a …

Synthesis And Performance Testing Of Ecm Fiber Scaffolds, Cassandra Reed

Graduate Theses and Dissertations

The progression of regenerative medicine has advanced the treatment of multiple illnesses and injuries throughout the years. A good example of the benefits of this research is the work that has gone into volumetric muscle loss (VML), where more than 20% of the muscle is loss. Skeletal muscle makes up 40% of the human body so a loss of that size greatly diminishes the strength, the flexibility, physiology, and quality of life of the injured individual. For that reason, various techniques are used to counteract the loss of structure and innate cellular signaling in order to circumvent that from happening. …

A Portable Point-Of-Care Device Using Joule Heating And Latent Energy Storage For The Temperature Regulation Of Isothermal Nucleic Acid Amplification Tests, Aubrey Lynn Schultz

Graduate Theses and Dissertations

Accurate and early diagnosis of infectious diseases extremely important. Rapid diagnosis allows for effective treatment and increases the chance for recovery without complications. Additionally, the ability to test the populace frequently, swiftly, and affordably significantly aids in containing wide-scale outbreaks. In terms of specificity and sensitivity, nucleic acid amplification tests (NAAT) are one of the best options for diagnosing infectious diseases. Isothermal NAATS present a unique opportunity to create diagnostic tests deployed at a Point-of-Care (POC) level. Specifically, loop-mediated isothermal amplification (LAMP) and recombinase polymerase amplification (RPA) have the potential to deliver reliable POC diagnostics in low-resource settings. When designing …

Privacy-Preserving Cloud-Assisted Data Analytics, Wei Bao

Graduate Theses and Dissertations

Nowadays industries are collecting a massive and exponentially growing amount of data that can be utilized to extract useful insights for improving various aspects of our life. Data analytics (e.g., via the use of machine learning) has been extensively applied to make important decisions in various real world applications. However, it is challenging for resource-limited clients to analyze their data in an efficient way when its scale is large. Additionally, the data resources are increasingly distributed among different owners. Nonetheless, users' data may contain private information that needs to be protected.

Cloud computing has become more and more popular in …

Electrochemical Deposition In Energy Storage Devices, Witness Atutala Martin

Graduate Theses and Dissertations

Metals, whether in a solid or soluble ion form, are a vital part of any electrochemical storage system. More so, Li metal is widely considered as the ideal anode because of its low density and low electrochemical potential (-3.04 V vs. the standard hydrogen electrode – SHE). However, just like most metals, it does not plate or strip evenly during cycling which can lead to cycling performance issues, short cycling lifespans, and even safety concerns brought about by dendrites that can cause internal short-circuiting within cells. This research focused on investigating the electroplating of metals in both aqueous and non-aqueous …

Decoupling The Effects Of Interfacial Chemistry And Grain Size In Perovskite Stability, Mirra M. Rasmussen, Kyle M. Crowley, Miranda S. Gottlieb, Geneviève Sauvé, Ina T. Martin

Student Scholarship

No abstract provided.

Surface Energy And Microstructure: The Effect Of The Underlying Substrate On Perovskite Film Formation For Solar Cell Absorbers, Mirra M. Rasmussen, Kyle M. Crowley, Ina T. Martin

Student Scholarship

No abstract provided.

Towards Intelligent Structural Health Monitoring Of Infrastructure Systems: An Interdisciplinary Study Of Acoustic Emission Monitoring, Numerical Simulation, And Artificial Intelligence, Li Ai

Theses and Dissertations

Some complex infrastructure systems, such as nuclear facilities and bridges, are subject to structural damage due to environmental erosion, material deterioration, and other factors after long periods of use. Stress corrosion cracking (SCC) and alkali-silica reaction (ASR) have been identified as the primary degradation mechanisms for steel and concrete structures in nuclear facilities and bridges. Ensuring the integrity and operational safety of structures during their lifetime is an important task. Nondestructive methods and structural health monitoring can be used to detect damage caused by SCC and ASR instead of conventional visual inspection. Among the nondestructive methods, acoustic emission (AE) is …

Regulation Of Inflammatory Processes By Tryptamine, Cannabidiol And 2,3,7,8-Tetrachlorodibenzo-P-Dioxin, Nicholas Dopkins

Theses and Dissertations

Host immunity is a complicated system of pro-inflammatory and anti-inflammatory processes that respond to exogenous and endogenous threats to regulate host physiology, inhibit carcinogenesis, and protect from infections. Sustained deviance from normal immunological function occurs due to a variety of factors both endogenous and exogenous, with some factors that can dysregulate host immunity including: genetics, microbiota composition, toxin exposure, age, gender, and smoking. The etiology of inflammatory disorders is both convoluted and complex due to the sheer number of facets regulating host immunity. To better contribute to understanding how immunological dysregulation occurs we focused on how three anti-inflammatory compounds (tryptamine, …

A Multi Physics Integrated Solution For A High-Pressure Stage Turbine Efficiency And Durability, Sanjay Chopra

Theses and Dissertations

World electricity demand is projected to grow at an annual rate of ~ 2.1% to year 2040₁. EIA projects nearly 50% increase in world energy usage by 2050 led by growth in Asia.[28];[29]. It is predicted that the global electricity demand grows at approximately 1.6 % per year from approximately 2008 and forecasted to approximately 2035, twice the rate of primary energy demand. This raises electricity's usage in total final energy consumption from approximately 19% in 2018 to approximately 24% in 2040. Electricity demand growth is set to be particularly strong in developing economies. .[28];[29];[38] As an enabler, to meet …

Effects Of Overmolding Process Parameters On Bondzone Quality, Vivek Varma Penumetsa

Theses and Dissertations

Urban air mobility (UAM) vehicles refer to small sized systems that transport people or cargo by air. In recent years, the interest in UAM vehicles has risen to combat traffic congestion, provide faster delivery times, or provide easier access to remote places. To meet potential future demand, traditional aircraft manufacturers must introduce manufacturing technologies that can cope with high production rates. One manufacturing technology aircraft manufacturers are investigating is overmolding, a manufacturing technology common to the automotive industry. Overmolding combines the manufacturing and assembly cycles into one by injection molding a component on top of a substrate. The quality of …

An In Vitro Approach To Vascular Therapeutic Testing, Shahd Ali Hasanain

Theses and Dissertations

Aortopathies refer to a broad class of pathological conditions affecting the aorta and are a major cause of morbidity and mortality in the US. Specifically, aortic aneurysms and aortic dissections have diverse etiologies that are initiated by alterations in the tissue’s extracellular-matrix (ECM) proteins, namely collagen and elastin, thereby predisposing the aortic wall to weaken and rupture. Pentagalloyl glucose (PGG) has recently emerged as a non-surgical treatment to reduce the risk of dissection or rupture. PGG is a known antioxidant and anti-inflammatory which has been shown to have ECM-restorative qualities that enhance collagen and elastin’s functional properties. Prior studies using …

Robust Adaptive Model Predictive Control Of Nonlinear Sample-Data Systems, Lixing Yang

Theses and Dissertations

In the past decades, model predictive control (MPC) has been widely used as an efficient tool in areas such as process control, power grids, transportation systems, and manufacturing. It provides an approach that aims to design stabilizing feedback to the system so that the performance criterion gets minimized while the state and input constraints get satisfied. In many situations, MPC may outperform other approaches to design and implement feedback control systems. Furthermore, MPC may solve optimization problems with large and practically important sets of multiple-input multiple-output (MIMO) systems efficiently. A typical implementation of MPC predicts the optimal control inputs that …

Reduced Order Modeling Based On Hybrid Snapshot Simulation, Feng Bai

Theses and Dissertations

Reduced order model (ROM) is an emerging technique for rapid and efficient numerical simulation and computation in science and engineering applications. The ROM consists of two stages: (1) the offline snapshot simulation to produce high-quality snapshot data representative of model trajectories, from which the projection subspace can be extracted and used for ROM construction; and (2) the online simulation to utilize the ROM built in stage 1. The snapshot simulation is traditionally performed with full order model (FOM) and is computationally demanding, which is one of the most critical limiting factors for the development and deployment of ROM in real-world …