Engineering Commons^™

Adaptive Physical Human-Robot Interaction (Phri) With A Robotic Nursing Assistant., Sumit Kumar Das

Electronic Theses and Dissertations

Recently, more and more robots are being investigated for future applications in health-care. For instance, in nursing assistance, seamless Human-Robot Interaction (HRI) is very important for sharing workspaces and workloads between medical staff, patients, and robots. In this thesis we introduce a novel robot - the Adaptive Robot Nursing Assistant (ARNA) and its underlying components. ARNA has been designed specifically to assist nurses with day-to-day tasks such as walking patients, pick-and-place item retrieval, and routine patient health monitoring. An adaptive HRI in nursing applications creates a positive user experience, increase nurse productivity and task completion rates, as reported by experimentation …

Hardware Implementation Of Boost Power Factor Correction Converter., Shruti Motilal Deore

Electronic Theses and Dissertations

Nowadays, there has been an increasing demand of unity power factor in electrical power sector. Due to the nonlinear nature of load equipment, switching devices, source voltage and current are out of phase with each other. Many power converters topologies are used for the power factor correction. The boost converter with controller is most common for power factor correction circuits. The controller objective is to maintain the output voltage regulation and input current tracking with source voltage. The voltage ripple present due to the ac component of the current tracking objective, hence instead of ignoring that ripple, it is used …

An Explainable Recommender System Based On Semantically-Aware Matrix Factorization., Mohammed Sanad Alshammari

Electronic Theses and Dissertations

Collaborative Filtering techniques provide the ability to handle big and sparse data to predict the ratings for unseen items with high accuracy. Matrix factorization is an accurate collaborative filtering method used to predict user preferences. However, it is a black box system that recommends items to users without being able to explain why. This is due to the type of information these systems use to build models. Although rich in information, user ratings do not adequately satisfy the need for explanation in certain domains. White box systems, in contrast, can, by nature, easily generate explanations. However, their predictions are less …

Solarpede: An Untethered Micro Robot Powered By Light., Jordan Fredrick Klotz

Electronic Theses and Dissertations

Micro-Robotics looks to implement robotics principles at a small scale and has gained popularity in recent decades as a gateway to new research areas such as micro-factory applications. The SolarPede is a second-generation, cm-scale micro-crawler designed for such micro factory applications which is equipped with a legged locomotion system and an electronic backpack. The SolarPede is an evolution of its predecessors and features power and signal conditioning capabilities, gait pattern generation, and Bluetooth connectivity. The components which make up SolarPede have been full validated and tested, and its systems have been realized in the form of a body made from …

Purification Of Biomass Hydrolyzates For The Promotion Of Xylose Diester Formation, Laura Fernandez

Electronic Theses and Dissertations

The application of a novel xylose isolation procedure using phenyl boronic acid esterification has been limited to the hydrolyzates of low extractive biomasses like hardwoods and agricultural resides. Hydrolyzates with lower sugar and higher extractive concentrations, like softwoods, have not yielded xylose, or even xylose diester (XDE), the first intermediate product in the new process, under the same conditions. This research applied evaporation concentration, adsorbent separation and membrane filtration to these lower performing biomass hydrolyzates to maximize the yield of the XDE formation step of the new xylose extraction process. Lab-scale tests of these techniques were applied to pine hydrolyzate …

Triple-Junction Solar Cells : In Parallel., Levi C Mays

Electronic Theses and Dissertations

This paper looks into the current inefficiency of solar cells and attempts a few alternative solar cell structures in order to provide a more effective source of renewable energy. Currently, multi-junction solar cells are being developed to capture the sun’s light more efficiently. One of the ideas in this paper is to add a window to see if the addition of such a layer into a junction will increase the voltage while maintaining nearly the same current output. Central to this paper is the rearranging of the conducting layers of the multi-junction cell so that the junctions can be connected …

Fluid Flow Analysis Of Diluted Evaporating American Whiskey Droplets., Martin J. Brown Vi

Electronic Theses and Dissertations

The recent discovery of the unique structures, whiskey webs, formed when the evaporation of diluted American whiskey, has raised many questions as to the nature of the structures. Their formation process follows as such: (1) dilution of the whiskey to form nanoaggregates, (2) formation of a monolayer at the air-liquid interface, (3) chaotic ethanol evaporation caused monolayer collapse (via dynamic pressure), (4) bulk fluid evaporation caused monolayer collapse (via reduction of surface area), where the web-like structures reside on the surface, and finally, (5) web-like structures deposit on the substrate. The webs imaged via SEM had a striking resemblance to …

Formally Designing And Implementing Cyber Security Mechanisms In Industrial Control Networks., Mehdi Sabraoui

Electronic Theses and Dissertations

This dissertation describes progress in the state-of-the-art for developing and deploying formally verified cyber security devices in industrial control networks. It begins by detailing the unique struggles that are faced in industrial control networks and why concepts and technologies developed for securing traditional networks might not be appropriate. It uses these unique struggles and examples of contemporary cyber-attacks targeting control systems to argue that progress in securing control systems is best met with formal verification of systems, their specifications, and their security properties. This dissertation then presents a development process and identifies two technologies, TLA+ and seL4, that can be …

Simulation Of A Continuum Tumor Model Using Distributed Computing., Dylan A Goodin

Electronic Theses and Dissertations

Mathematical modeling aims to provide a theoretical framework for understanding tissue dynamics and for establishing treatment response for diseased tissues, such as tumors. Previously published continuum models have successfully represented idealized two-dimensional and three-dimensional tissue for short periods of time. A recently published continuum model of cancer increases model complexity and describes three-dimensional tissue that, due to the required complexity of the geometric multigrid solver, can only be feasibly applied to millimeter-scale simulations. Furthermore, the computational cost for such models has hindered their application in the laboratory and in the clinic. With computational demands greatly outpacing current openMP-based approaches on …

Feasibility Study Of Intelligent Lvad Control For Optimal Heart Failure Therapy., John A. Karlen Iii

Electronic Theses and Dissertations

Background: Left ventricular assist devices (LVAD) are operated at constant speeds (rpm), consequently, pump flow is passively determined by the pressure difference between the LV and aorta. Since the diastolic pressure gradient (~70 mmHg) is much larger than the systolic gradient (~10 mmHg), the majority of pump flow occurs during systole. This limitation results in sub-optimal LV volume unloading, LV washing, and diminished vascular pulsatility that may be associated with increased risk for clinically-significant adverse events, including stroke, bleeding, arteriovenous malformations, and aortic insufficiency. To address these clinical adverse events, an intelligent control strategy using pump speed modulation was developed …

Potential Value-Added Utilization Of Wood Ash In Construction Materials, Naveen Saladi

Electronic Theses and Dissertations

Wood ash is a byproduct from biomass power plants. Most of the wood ash is currently being disposed of as landfilling material that causes severe economic and environmental concerns. This project focuses on the feasibility of using this wood ash in construction materials. Wood ash was found to contain varieties of mineral phases including calcium carbonate, calcium aluminate, and quartz. Based on the chemical composition, the efficacy of wood ash (i) as supplementary cementitious materials (SCM), (ii) in the controlled low strength materials (CLSM) production and (iii) Portland cement production was evaluated.

Wood ash with adequate pozzolanic properties can be …

Prediction Of Paper Coating Mechanical Behavior Based On Particle-Scale Models, Daniel H. Varney

Electronic Theses and Dissertations

The mechanical properties of pigmented coatings are important for a number of situations; including coated paper, architectural paints, and structures in flexible lithium ion batteries. Coated paper and board undergo a variety of post coating application processes which have the potential to cause serious quality problems such as cracking, picking, and crack-at-the fold (CAF). Because a large number of parameters are known to influence the results, fundamental models are needed to help describe these processes and link them to the coating formulations and to the defects.

A discrete element method (DEM) computer model was developed to describe the pigment level …

Investigating The Time-Dependent And The Mechanical Behavior Of Wood Plastic Composite Lumber Made From Thermally Modified Wood In The Use Of Marine Aquacultural Structures, Murtada A. Alrubaie

Electronic Theses and Dissertations

Wood Plastic Composite (WPC) lumber based on a patent-pending formulation is being explored for use in the manufacture of an aquaculture fish cage structure (Aquapod net pen cage), as an alternative to the current high density polyethylene (HDPE) lumber. The use of WPC lumber in structural applications in marine environments requires a comprehensive effort to understand the material viscoelastic behavior and the structural performance of the WPC lumber in marine environments where the WPC lumber is exposed to the combined effect of saltwater immersion and temperature (hygrothermal). The evaluation of the viscoelastic behavior of WPC lumber in marine environments was …

Process Optimization Of Levulinic Acid Production From Seaweeds And Its Upgrading To Tdo Oil, Maurvin Patel

Electronic Theses and Dissertations

Levulinic acid (LA) is a platform chemical and it can be upgraded to various products like bio-oil. The acid hydrolysis of cellulose is a widely researched pathway to make LA. However, investments to produce LA commercially can be subjected to risks due to feedstock price volatility and high processing costs. Such risks can be reduced by expanding the feedstock portfolio to produce LA from feedstock beyond wood and improving the energy efficiency of the process. One little investigated feedstock for production of LA is macro algae (seaweed). Seaweed is potentially attractive because it has low content of lignin or 5 …

Conversion Of Pretreated Hardwood To Medium-Chain Fatty Acids For Production Of Biolubricants, Koorosh Kashkooli

Electronic Theses and Dissertations

Medium-chain fatty acids (MCFA, e.g., hexanoic, heptanoic and octanoic acid) are versatile chemical compounds that are suitable precursors for the production of high-carbon-number, value-added chemicals such as bio-based lubricants. Short-chain fatty acids (SCFA, e.g., acetic, propionic, butyric, valeric acid) and methane are the natural fermentation products of anaerobic digestion, however, they have a lower value compared to MCFAs. Our current investigation seeks to integrate the production of MCFAs through chain elongation fermentation of pretreated biomass with catalytic conversion of MCFAs to lubricant molecules. By adding reducing agents such as ethanol and lactic acid to the anaerobic digestion, and inhibiting methanogenesis, …

Tidal And Subtidal Processes At The Mouth Of A Macrotidal Estuary, Rachel Chambers

Electronic Theses and Dissertations

Secondary flows and mixing have been shown to influence sediment transport, the vertical salinity gradient, and the exchange flow in estuaries. Typically, these hydrodynamic properties are investigated with respect to time and depth and their variability across the estuary is neglected. However, recent studies have shown that secondary flows and mixing, along with mechanisms that influence them, can exhibit lateral variability. Additionally, the variability of these hydrodynamic properties has not been studied in macrotidal estuaries, where the increased tidal forcing could affect the strength and cross channel variability.

There are two primary objectives of this thesis. The first objective is …

3d Printed Bioinspired Vascularized Polymers, Kayla Marquis

Electronic Theses and Dissertations

Biological vascular systems contain a network of three-dimensional channels that transport and deliver necessary nutrients throughout the organism. These systems are complex, adaptable, and possess the ability to detect and respond to external stimuli as needed. In this work, we mimic the complexity and adaptability of biological systems by incorporating vascular systems into polymeric materials. Vacant channels are created using a fugitive ink technique along with 3D gel printing. Upon completion of vascular channel construction, proof of principle testing is performed by inoculating the polymeric surface with bacteria and adding antibiotics to the vascular channels. The system is then characterized …

Perspectives On Water Resources Risk, Policy, And Stewardship, Anne Marie Lausier

Electronic Theses and Dissertations

Water management approaches have historically optimized water for human use and placed lower emphasis on the relationship between ecosystems and humans. Despite efforts to balance human and ecosystem needs, existing management approaches tend to prioritize some needs, knowledges, and values over others. Natural and anthropogenic changes pose challenges to water governance institutions due to policy inflexibility, and may lead to ecosystem degradation, water stress, and conflict among water users. This work seeks to redress these shortcomings through three scholarly contributions. First, a conceptual framework for Water Resources Stewardship is developed in support of equitable and adaptive solutions under changing conditions. …

Global Performance Testing, Simulation, And Optimization Of A 6-Mw Annular Floating Offshore Wind Turbine Hull, Hannah L. Allen

Electronic Theses and Dissertations

Floating offshore wind turbine (FOWT) hull technologies are evolving rapidly with many technically viable designs. However, a commercially dominant architecture has yet to emerge. This thesis presents a methodology for evaluation of the hydrodynamic performance of an annular FOWT hull. This hull shows significant promise from a manufacturing and installation standpoint, but limited performance data exists. This thesis will provide ample documentation on scale model testing of an annular FOWT hull as well as the corresponding numerical validation approach and opportunities for design improvement.

The first portion of this work involves testing a 1/100th-scale model in the Harold Alfond Wind …

Tide And Storm Surge Dynamics In Estuaries Of Variable Morphology, Preston Spicer

Electronic Theses and Dissertations

Storm surges are the most destructive component of coastal storms, and climate change is predicted to enhance the frequency of intense storm events in the future. Currently, most storm surge forecasting assumes linear surges and the extent to which this assumption leads to model inaccuracies is currently unknown. The goals of this research are to characterize storm surge in estuaries and determine the contribution of nonlinear tide-surge interaction to total inland surges. A citizen science experiment was conducted in four estuaries in Maine. Results show the estuary shape influences surges through convergence, friction and man-made constrictions. These mechanisms modified total …

Development Of Daily, Monthly, Inter-Annual, And Mean Annual Hydrological Models Based On A Unified Runoff Generation Framework, Marwan Kheimi

Electronic Theses and Dissertations

The main goal of this dissertation develops a unified model structure for runoff generation based on observations from a large number of catchments. Furthermore, obtaining a comprehensive understanding of the physical controlling factors that control daily, monthly, and annual water balance models. Meanwhile, applying the developed Unified model on different climate conditions, and comparing it with different well-known models. The proposed model was compared with a similar timescale model (HyMOD, and abcd) and applied on 92 catchments from MOPEX dataset across the United States. The HyMOD and abcd are a well-known daily and monthly hydrological model used on a variety …

Energy Expenditure And Stability During Self-Paced Walking On Different Slopes, Alanna Raffaelli

Electronic Theses and Dissertations

Metabolic power and cost of transport (COT) are common quantifiers for effort when performing tasks including walking and running. Most studies focus on using a range of normal walking speeds over level ground or varied slopes. However, these studies use fixed-speed conditions. Fatigue, stability, metabolic expenditure, heart rate, and many other factors contribute to normal walking speed varying over time. This study aimed to show that allowing a subject to walk with a self-paced speed should correlate to a minimum COT at a given slope. This study also aimed to determine if a preferred slope exists based on minimizing metabolic …

Conceptualization And Fabrication Of A Bioinspired Mobile Robot Actuated By Shape Memory Alloy Springs, Lietsel Richardson

Electronic Theses and Dissertations

This work is an experimental study and fabrication of design concepts to validate the feasibility of smart materials and their applications in bio-inspired robotics. Shape-Memory Alloy (SMA) springs are selected as the smart material actuators of interest to achieve locomotion in the proposed mobile robot. Based on a previous design of the robot, this work focuses on both implementing a new locomotion concept and reducing size and weight of the previous design, both using SMA based actuators. Objectives are met in consideration of the conceptual mechanics of circular robot locomotion. The first prototype is a variation of the original design. …

Applications Of Deep Learning Models For Traffic Prediction Problems, Rezaur Rahman

Electronic Theses and Dissertations

Deep learning coupled with existing sensors based multiresolution traffic data and future connected technologies has immense potential to improve traffic operation and management. But to deal with complex transportation problems, we need efficient modeling frameworks for deep learning models. In this study, we propose two different modeling frameworks using Deep Long Short-Term Memory Neural Network (LSTM NN) model to predict future traffic state (speed and signal queue length). In our first problem, we present a modeling framework using deep LSTM NN model to predict traffic speeds in freeways during regular traffic condition as well as under extreme traffic demand, such …

Point Cloud Technology For Analysis Of Existing Structures, Jacob Cano

Electronic Theses and Dissertations

For this thesis, a study was completed on two different structures on the UCF Orlando campus through the use of both structural plans and point cloud technology. The results sought to understand the viability of point cloud technology as an accurate tool for the static and dynamic modal analysis of existing structures. For static analysis, a portion of the framing of Spectrum Stadium was rendered, modeled, analyzed and compared to a previous case study. The results emphasized how different users can render dissimilar member sizes and lengths due to human judgment on point cloud visuals. The study also found that …

Streamflow Prediction In Ungauged Basins Located Within Data-Scarce Regions, Mohammadhossein Alipour

Electronic Theses and Dissertations

Preservation and or restoration of riverine ecosystem requires quantification of alterations inflicted by water resources development projects. Long records of streamflow data are the first piece of information required in order to enable this analysis. Ungauged catchments located within data-scarce regions lack long records of streamflow data. In this dissertation, a multi-objective framework named Streamflow Prediction under Extreme Data-scarcity (SPED) is proposed for streamflow prediction in ungauged catchments located within large-scale regions of minimal hydrometeorologic observation. Multi-objective nature of SPED allows for balancing runoff efficiency with selection of parameter values that resemble catchment physical characteristics. Uncertain and low-resolution information are …

Characterization Of Florida Landfills With Elevated Temperatures, Ryan Joslyn

Electronic Theses and Dissertations

The occurrence of elevated temperatures within landfills is a very challenging issue for landfill operators to detect and correct. Little is known regarding the causes of elevated temperatures (ETs) and the number of landfills currently operating under such conditions. Therefore, the goal of this research was to determine which landfills within Florida have been impacted by ETs, and to develop a more complete understanding of the factors that may lead to these landfills becoming elevated temperature landfills (ETLFs). Historical landfill gas wellhead data, waste deposition reports, and landfill site geometry were collected for 27 landfill cells through the FDEP OCULUS …

Vibration Reduction Of Mistuned Bladed Disks Via Piezoelectric-Based Resonance Frequency Detuning, Garrett Lopp

Electronic Theses and Dissertations

Recent trends in turbomachinery blade technology have led to increased use of monolithically constructed bladed disks (blisks). Although offering a wealth of performance benefits, this construction removes the blade-attachment interface present in the conventional design, thus unintentionally removing a source of friction-based damping needed to counteract large vibrations during resonance passages. This issue is further exacerbated in the presence of blade mistuning that arises from small imperfections from otherwise identical blades and are unavoidable as they originate from manufacturing tolerances and operational wear over the lifespan of the engine. Mistuning is known to induce vibration localization with large vibration amplitudes …

Decentralized Consensus-Based Control Allocation For Some Dynamical Systems, August Mark

Electronic Theses and Dissertations

In this dissertation, three separate studies, wherein techniques from graph theory and consensus control are used to address control allocation problems, are presented. In the first study, a decentralized allocator is presented for synthetic jet actuators and control surfaces onboard a small unmanned aerial vehicle to cooperatively generate desired aerodynamic moments. First order linear dynamics are assumed for both the synthetic jet actuators and control surfaces. A weighted consensus algorithm with limited feedback is used for the aerodynamic moment contribution allocator considering constraints. In the second study, the same allocation problem as in the first study is considered, but the …

Resource Optimization In Visible Light Communication Using Internet Of Things, Akash Dey

Electronic Theses and Dissertations

In the modern day, there is a serious spectrum crunch in the legacy radio frequency (RF) band, for which visible light communication (VLC) can be a promising option. VLC is a short-range wireless communication variant which uses the visible light spectrum. In this thesis, we are using a VLC-based architecture for providing scalable communications to Internet-of-Things (IoT) devices where a multi-element hemispherical bulb is used that can transmit data streams from multiple light emitting diode (LED) boards. The essence of this architecture is that it uses a Line-of-Sight (LoS) alignment protocol that handles the hand-off issue created by the movement …