Engineering Commons^™

The Travel And Tourism Competitiveness Index: Examining The Reciprocal Relationship Among The Ttci Factors Relative To Porter’S (1998) Diamond Model And Airline Passenger Seat Capacity For The Countries Of The World, Hani Abdullah

Theses and Dissertations

The current study tested the application of Porter's (1998) diamond model of international competitiveness to the travel and tourism (T&T) industry by examining the relationship among the 14 factors of the travel and tourism competitiveness index (TTCI) to the model's four dimensions. The assignment of TTCI factors to these dimensions was guided by Dwyer and Kim (2003) and Ritchie and Crouch (2010). The study also examined the relationship between TTCI factors and airline passenger seat capacity, which was measured as the per capita annual average of weekly available seat kilometers. The sample comprised 136 countries, which represented 70% of the …

Analysis Of Pile Driving Monitoring Equipment, Robert Joseph Rogulski Iii

Theses and Dissertations

Rebound is a problem affecting pile driving in Florida. Significant rebound can require excessive blows for a pile to reach bearing capacity and may damage the pile. In order to study rebound, precise instrumentation is required. For that reason, the objective of this thesis is to evaluate the Inopile’s Pile Driving Monitor (PDM) as a tool for measuring the rebound of large diameter pre-stressed concrete piles driven with open ended diesel hammers. Six sites from Florida were selected for testing. Five of the sites had pile driving and two of them had standard penetration testing (which was used as an …

Controlling Co Dose From Corm-Loaded Electrospun Scaffolds With Diffusion-Based Modeling And Experimental Assessment Of Endothelial Cell Response, Kenyatta S. Washington

Theses and Dissertations

Cardiovascular disease (CVD) accounts for one in every five deaths in the United States alone due to occlusion in small diameter (< 6 mm) vessels. The current treatment options includes bypass grafting; however, more than 30 percent of patients do not have viable saphenous veins for autologous grafting [1]. Therefore, tissue engineering is being considered as an alternative approach. The overall goals of this project were to develop a tissue engineered vascular graft with the incorporation of carbon monoxide releasing molecules (CORMs) and to determine the impacts of carbon monoxide (CO) on endothelial cells (ECs) with the goal of promoting a functional endothelium within the graft. This was accomplished through two complementary studies: investigating the impacts of CO-loaded electrospun scaffolds on ECs for cardiovascular applications and diffusion-based modeling of drug delivery of gasotransmitters from tissue engineered scaffolds. In the first study, we extended the maximum in vitro incubation time to permit better cellular attachment and proliferation with a newly-synthesized, more hydrophobic CORM (DK3) and established the impact of CORMs on EC viability and function (e.g. reactive oxygen species (ROS) products, and ROS levels). We further investigated toxicity and biocompatibility of a newly synthesized CORM (DK4) loaded within PCL thin films and nanoparticles. We concluded that the DK4 and other compounds are not toxic at doses ranging from 0 – 50 μg/mL to the ECs both within nanoparticles that can be internalized within cells. We also conducted an in vivo pilot study to determine graft biocompatibility and preliminary results showed that CORM implants maintain mechanical integrity, support blood flow, and do not show toxicity for up to six weeks. In the second study, we validated a computational model and analyzed the output of CO delivery to better understand and control local dose. For CO release, this model is necessary because of the limitations with real-time experimental analysis and the need to better understand the dose available to the cells. We demonstrated that the validated model can be used to predict drug availability to cells for a variety of scaffolds and drug molecules. Our simulated results suggest that only a fraction of the initial concentration of gasotransmitters released from fibers that enters the interstitial fluid in vivo, or culture media in vitro, will be available to cells. We also demonstrated that fiber orientation and fiber diameter are important for drug delivery, but fiber density provides even more important information. The more contact area within the fiber scaffolds is equivalent to experimental conditions with more cell attachment and spreading. These parameters are not only important for traditional tissue engineering, but also for drug delivery. Overall, these results demonstrate the feasibility of making a tissue engineered vascular graft with the incorporation of CORMs and validating he importance of computational modeling of diffusion-based transport of CO. Future work will involve performing surface modifications to enhance cell attachment and proliferation, using the developed computational model to better predict dose available to cells, and experimentally determining impact of CO dose on ECs.

A Coastal Estuarine Ensemble Forecasting System, Peyman Taeb

Theses and Dissertations

This research has been conducted in an effort to reduce the computational costs associated with high-resolution coastal estuarine modeling in ADCIRC. It was proposed that model scalability will be significantly enhanced if the conventional single-domain technique is replaced by a nesting method. Preliminary testing indicated the potential for 50% to more than 80% simulation runtime reduction (depending on the study site) by implementing a nesting technique. Once the concept was proved, the development of an operational, ensemble-based forecasting system, exclusively for the east coast of Central Florida and the IRL system, was implemented. The system, referred to as Ensemble Multistage, …

Survival Theory Modelling For Information Diffusion, Akshay Aravamudan

Theses and Dissertations

Information diffusion is the spread of information within a network. In this thesis, we model information diffusion as a survival process. We have adopted an existing algorithm called NetRate for modelling information diffusion. This model involves finding the distribution of trasmission time between two nodes in the network. We modify NetRate’s concave-down log-likelihood expression by adding partial parentage information and formulate an Expectation-Minimization (EM) algorithm to learn the parameters. We also describe a simulation scheme for NetRate inspired by point process simulation strategies. Using the assumptions of the NetRate model, we derive a a method to model popularity as a …

Developing An Automation Locus Of Control Scale, Maarten Nelson Devon Edwards

Theses and Dissertations

The industrial and domestic proliferation of automation is such that it has become a core component of the human experience. Both automation design paradigms and human performance must be scrutinized in order to ensure the safety, security, effectiveness and efficiency of man-machine systems across a multitude of domains (Fitts, 1951; Parasuraman, Sheridan, & Wickens, 2000; Rasmussen, 1983). Therefore, the purpose of this study was to develop and validate a measure for the evaluation of control perceptions in the context of human-automation interactions. The scale was developed using a deductive approach to measure development adapting from Rotter (1966) and Levenson (1973) …

Developing An Interview Protocol For An Engineering Design Capstone Course To Measure Student Motivation And Engineering Identity, Mckenzie Clark

Theses and Dissertations

This thesis examines the process of developing an effective in-depth interview protocol to measure student motivation and engineering identity. Several methods were employed during the creation, refining, and analysis portions of this study to ensure reliability and validity of the qualitative research instrument. In a multifaceted course such as senior capstone design, it is integral to ensure students are receiving a value adding experience. In most universities across the United States, senior capstone design is a multiple semester sequence where design is heavily emphasized and students are encouraged to test their skills, both technical and nontechnical, by solving and implementing …

Performance Analysis Of A Parabolic Trough Solar Collector, Feras Abdullah Mohammed Alghamdi

Theses and Dissertations

Solar energy technologies are growing vastly in both developed and developing countries. The parabolic trough solar collector (PTSC) technology is the most widely used system among concentrated solar technologies. In this thesis, three models were developed to investigate the performance of the PTSC; these models are 2D & 3D numerical models and 1D analytical model. Each model considers three absorber tube configurations, vacuum annulus, air-filled annulus, and bare absorber tube. The specifications of the Luz LS-2 PTSC were used throughout the study. Since the study considers the 3D model, a realistic non-uniform heat flux distribution around the receiver tube was …

Modeling To Predict The Salt Transport Between A Scale Model Estuary And The Unconfined Aquifer With Groundwater Flow, Abeer Ibraheem Khazaly

Theses and Dissertations

In many field studies, variation in fluid density may have important effects on controlling groundwater flow and solute transport processes. These studies include: Indian River Lagoon (IRL), a coastal estuary, located on the east coast of Florida, saline disposal basins, radioactive waste disposal and contaminant spills. In the environment, where the fresh groundwater region is in direct contact with the saline seawater region in coastal aquifers, dynamic equilibrium normally exists between these two regions, but there are numerous human and environmental factors that can adversely impact the equilibrium and lead to severe saltwater contamination of the freshwater region. Intrusion of …

Redeployment And Demonstration Of The Video Guidance Sensor For Proximity Maneuvers, Xiangyi Li

Theses and Dissertations

This paper presents the redeployment and demonstration of the Photogrammetric Video Guidance Sensor (PVGS) as a position and attitude sensor for proximity maneuvers and formation flight of small spacecraft. The original PVGS was developed to use a smartphone as its hardware and an Android application as its software; however, this paper provides a possibility for using a smaller and cheaper single-board computer, Raspberry Pi as new hardware, and for using a Java program run in Linux as its software. We finally achieved the approximate performance compared to the original PVGS. At the current stage, a PID controller was supposed to …

Advancing Numerical Calculation Of Mixed Sized Sediment Transport And Morphology Change, Irene Margaret Watts

Theses and Dissertations

Numerical modeling of sediment transport and morphologic change has become a powerful tool for studying and working in the coastal zone. Numerical calculation can assist in a broad range of projects from regional sediment management to beach nourishment as well as evaluating environmental aspects of dredging and placement and implications to water quality and turbidity. Success in application of these tools is partially dependent on the quality of characterization of the sediments in the field. These parameters could include grain size, mineralogical composition, specific gravity and fall velocity. Sediment transport formulations are sensitive to the spatial representation of the sediments …

Gene Expression Studies For Analyzing Effects Of Space Radiation In Tissues, Amatulshakoor Mohammed Farooqui

Theses and Dissertations

Human exploration beyond the earth's orbit poses many risks for the crew on these missions. One of the major health risks is exposure to space radiation environment beyond the earth’s magnetic field. The space environment exposes astronauts to high levels of ionizing radiation such as galactic cosmic rays. The radiations can have acute and delayed effects on the human body. The primary response to tissue injury is increased oxidative stress and inflammation. The overall objective of this study was to analyze the effects of ionizing radiation in heart tissue by quantifying its impact on the expression of genes that correlate …

Integrating A Modified Pulse Amplitude Modulation (Pam4) Scheme With Two Spatially Multiplexed Channels In Optical Fiber Communication Systems, Bilas Chowdhury

Theses and Dissertations

A multi-input multi-output (MIMO) based optical fiber multiplexing architecture known as Spatial Domain Multiplexing (SDM) adds a new dimension to optical fiber communication systems by spatially reusing the optical frequencies. SDM allocates different spatial location for different input signals based on the input launch angles. These input signals propagate helically inside the carrier fiber. They abide total internal reflection and exit as concentric donut shaped rings while travelling the fiber. These SDM channels do not exhibit any crosstalk or intersymbol interference. SDM systems can also complement different modulation techniques such as Return to Zero (RZ), Non-Return to Zero (NRZ), and …

Surface Phonon Polariton-Enhanced Ring Resonator And E-Plane Hybrid Ring Coupler, Cláudio Augusto Barreto Saunders Filho

Theses and Dissertations

Surface polaritons are known for providing the ability to confine light beyond the Abbe’s limit of diffraction. While metals efficiently support surface plasmon polaritons in the visible-UV spectrum, some semiconductors can support surface phonon polaritons in the infrared. Ring resonators are devices with high integration level with optical interconnects and with applications including filters, directional couplers, modulators and interferometers. Loss associated to ring curvature yields ring radius on the order of tens of free-space wavelengths. SPhP-enhanced micro-ring resonator was proposed and it was shown that ring dimensions are reduced. Advances in nanofabrication processes allow the design of optical interconnects using …

Electrochemical Fabrication Of Elastin-Containing Bi-Layered Scaffold For Vascular Tissue Engineering Applications, Thuy-Uyen Ky Nguyen

Theses and Dissertations

Lack of a viable vascular graft for the replacement of diseased small diameter blood vessels (< 4 mm) has encouraged the development of a self-repairing tissue engineered vascular graft (TEVG) as a promising alternative source. Although many different fabrication approaches have been devised to generate TEVGs using both natural and synthetic biomaterials, a functional TEVG that can serve as an effective replacement of diseased small-diameter blood vessels (< 4 mm) is still elusive mainly due to concerns associated with thrombosis and intimal hyperplasia. One approach to improve the clinical outcome of vascular grafts is to develop a 3D biomimetic scaffold that provides the essential physicochemical cues (i.e., compositional, topographical) to modulate cellular response (i.e., cell phenotype, endothelialization, de novo elastic matrix production) and thereby aid in tissue repair and remodeling. This approach entails the development of a novel 3D scaffold that provides an aligned collagen platform to guide smooth muscle cell (SMC) orientation

and insoluble elastic matrix (i.e., native form of elastin) to promote SMC contractility and thereby prevent overproliferation and hence alleviate concerns with intimal hyperplasia. In addition, the scaffold must comprise of a smooth luminal side to support the formation of a continuous endothelium that is essential to prevent thrombosis. Most existing biofabrication methodologies to generate vascular scaffolds (e.g., extrusion, electrospinning) have limited scope because of the inability to incorporate insoluble elastic matrix within the aligned collagen framework due to the disparity in the size …

Bioprinting Of 3d Perfusable Structures Using An Extrusion-Based System, Prabhuti Kharel

Theses and Dissertations

Bioprinting is a technique of creating 3D cell laden structures by accurately dispensing biomaterial to form complex synthetic tissue. Bioprinting is a process of additive manufacturing where the cell functionality and viability is preserved within the printed structure. Bioprinting is a promising alternative to produce physiologically relevant 3D structures that mimic the native tissue. However, fabrication of complex structures with vascularization has been a major challenge in bioprinting. To overcome this challenge sacrificial printing in combination with fugitive inks has been explored to create vascularize structures. The objective of this study is to fabricate hollow channels within the bioprinted structure …

Application Of The Gradient Projection Method To An Optimal Control Problem In Quantum Biology, Rashad Abdulla

Theses and Dissertations

Quantum biology is an emerging field which seeks to understand and analyze the effects of quantum mechanical phenomena on biological systems. One such phenomenon is the formation of radical pairs, compounds which exist in a quantum superposition of two states until they collapse into one or the other. The probability of the collapse into a preferred state can be calculated from the Schrödinger equation, and is in fact dependent on external magnetic fields. This project utilizes principles of mathematical optimal control and quantum biology to determine the precise sequence of magnetic field pulses that maximize the probability of achieving the …

A Mixed Method Study On The Impact Of Industry Sponsored Projects On Senior Capstone Design Student’S Motivational Factors, Devanshi Shah

Theses and Dissertations

This thesis examines the change in student motivation through a yearlong senior capstone design course with respect to their choice of project type. The senior capstone design projects offered at the university fall into one of two major project types: industry sponsored and nonindustry sponsored. The students opt for either of the two major project types based on their interest and future career goals. The students were given an adapted version of Motivated Strategies for Learning Questionnaire (MSLQ) to self-identify their motivation levels by rating various questions on a 7-point Likert scale. The surveys were conducted at two different points …

Feasibility Study And Hydrodynamics Of Transformable Submersible Hydrofoil Trimaran, Yipeng Pan

Theses and Dissertations

It has been the endeavor of naval architects to design innovative hull forms to address the political, socio-economic climate and sustainability around the world. It is imperative that countries be able to protect their sea lanes and coastal zones from surveillance and infiltration from hostile foreign entities. Hence there is a need to develop radically different hull form, which possess the elusive ability and are capable of high-speed. In order to fulfill the idea, the hypothesis envisioned in this thesis is: the Transformable Submersible Hydrofoil Trimaran (TSHT) as an innovative and ground breaking hull form would address the feasibility of …

Calibration Of The Rapidscat Microwave Brightness Temperature, Ali Al-Sabbagh

Theses and Dissertations

NASA RapidScat is the first satellite scatterometer that flown in non-Sun-synchronous orbit. Its unique orbit enabled collocated measurements with multiple satellite remote-sensing instruments that usually fly in Sun-synchronous orbits. RapidScat’s primary mission was retrieval of global ocean wind vectors from normalized radar backscatter measurements. The instrument operated onboard the International Space Station between September 2014 and August 2016 covering latitude range between ±51.6ᵒ . To serve as a cross-calibration reference with other instruments, RapidScat must be internally calibrated. This dissertation presents the first radiometric calibration of RapidScat brightness temperature measurements and describes the process that combines RapidScat’s active/passive mode, simultaneously …

A Queueing Theory-Based Modeling And Performance Analysis Of Push-To- Talk Over Cellular Networks, Hisham Zorghani

Theses and Dissertations

Public Safety organizations play a vital role in emergencies. Their ultimate goal is to protect people and save lives and properties during disasters. Public safety communities have been using narrowband Trunking systems for their communications for decades. These systems were designed with only voice communications in mind. Even though these narrowband systems have gone throughout many enhancement phases, yet their data capabilities are still limited. Long Term Evolution (LTE) has been selected by many countries including the United States to be the platform for next-generation Public Safety Networks(PSN). The 3GPP LTE standard is all-IP architecture mainly developed to boost its …

Lateral And Torsional Seismic Vibration Control For Torsionally Irregular Buildings, Osman Akyürek

Theses and Dissertations

During strong earthquakes or wind gusts, it is likely that buildings with torsional irregularity in the plan have an can be seriously damaged, partially collapsed or fully collapsed. This is because Torsionally Irregular Buildings (TIBs) may have significant aerodynamic torsion loads that increase the eccentricity between the center of mass and the center of rigidity, especially in dominant torsion modes. For this reason, torsion leads to excessive increase in lateral motions when dynamic loads excite the buildings. Torsional irregularity is one of the main failure causes during strong dynamic excitations due to earthquakes or wind gusts. Ignoring torsional irregularity in …

Geo-Locating Ues Using Multi-Output Decision Tree Regressor, Edel Goreil Dawood

Theses and Dissertations

Mobile communication networks constantly need to monitor and improve the quality of service and network coverage to their users, and to do so, radio measurements are required. One common method for gathering these measurements is Drive Tests (DT) in which vehicles equipped with measuring devices are sent to locations of interests. However, DT has several limitations one of which is that DT cannot be performed on indoor locations. Other approaches were later used; however, failed to prove a considerably higher efficiency. To address this need, mobile operators developed a standardized technique called Minimization of Drive Test (MDT) that take advantage …

Point Cloud Based Relative Navigation For Small Satellite Rendezvous, Branden William Blackwell

Theses and Dissertations

The thesis describes the development and testing of a point cloud based relative navigation sensor. The objective of this research is to provide a low cost, lightweight, low power, and low volume alternative to established rendezvous sensors , in order to enable small satellites to conduct missions such as in-space inspection, on-orbit servicing, and space debris removal. The sensor system must be able to provide relative position and orientation data to a control system independent of the cooperation of the target spacecraft or object. This is done using commercially available hardware (Microsoft Kinect v2) and an open source C++ library …

Mitigating Risk Tolerance Among General Aviation Pilots: Identifying Factors That Contribute To Ga Pilots’ Risk Perception, Nazif Sani Nuhu

Theses and Dissertations

The purpose of this study was to identify factors that contributed to general aviation (GA) pilots’ level of risk perception, which could then be manifested as an increase in risk tolerance. The study used an explanatory correlational design to determine what factors were related to risk perception. Research factors included gender, age, marital status, race/ethnicity, education level, flight hours, single- and multi-engine hours, hours as PIC, type of flight training, number of FAA licenses/ratings, number of hazardous events pilots were involved in, self-efficacy, aviation safety attitudes, level of psychological distress, and locus of control. The dependent variable was risk perception. …

Damping Coefficient Sensitivity Analysis Of High Rebound Soils In Florida, Aline Franqui

Theses and Dissertations

The dynamic response of soils is related to a damping factor, which represents the energy absorbed by the soil as the pile moves. Certain blends of fine sands, silts and clays are producing pile rebound during driving. For that reason, the objective of this thesis is to conduct a damping coefficient sensitivity analysis of high rebound soils in Florida. Forty cyclic triaxial tests from six sites in Central and Northern Florida were analyzed to evaluate damping. Two approaches were used, one based on the change in stress over time and a second based on the viscous energy absorbed per cycle. …

Establishing A People Qualification Framework At Embraer Executive Aircraft, Inc., Yassine Rayad

Theses and Dissertations

Technical training in the aviation industry is a multi-faceted and complex topic. Research efforts in aviation maintenance training are extensive, however, we observe a paucity of studies directly focused on aircraft manufacturing environments. Nevertheless, the recent growth of the training industry and the advent of more disruptive technologies such as virtual and augmented reality solutions are making training program design efforts more and more relevant. The research and design contributions presented in this thesis focus on the establishment of a people qualification framework at a local aircraft final assembly and testing plant in Melbourne, FL. The design thinking cycle was …

Rapidscat Backscatter Measurements Calibration, Ruaa Alsabah

Theses and Dissertations

Scatterometers are microwave radars deployed to estimate global wind speeds and directions over sea surface by measuring Normalized Radar Cross Section (σᵒ) of the sea. Measured is determined by the sea surface roughness that is modulated mostly by wind, thus establishing a relationship between and wind conditions. Wind vectors are retrieved by inverting an empirical Geophysical Model Function that relates measured to a wind vector (speed and direction) and radar measurement configuration (polarization, incidence, and azimuth angle). Careful scatterometer calibration is required for accurate wind retrieval. RapidScat is a National Aeronautics and Space Administration (NASA) Ku-Band scatterometer that was operated …

Study Of A Crew Transfer Vehicle Using Aerocapture For Cycler Based Exploration Of Mars, Larissa Balestrero Machado

Theses and Dissertations

This thesis presents the results of a conceptual design and aerocapture analysis for a Crew Transfer Vehicle (CTV) designed to carry humans between Earth or Mars and a spacecraft on an Earth-Mars cycler trajectory. The thesis outlines a parametric design model for the Crew Transfer Vehicle and presents concepts for the integration of aerocapture maneuvers within a sustainable cycler architecture. The parametric design study is focused on reducing propellant demand and thus the overall mass of the system and cost of the mission. This is accomplished by using a combination of propulsive and aerodynamic braking for insertion into a low …

Unified Model Combining The Boundary Conditions Encountered At The Input, The Carrier Optical Fiber And The Output In Spatially Multiplexed Optical Communication Channels, Gregory Lewis Lovell

Theses and Dissertations

Spatial domain multiplexing allows for expansion of optical fiber data rates by utilizing the spatial dimensions within the fiber. One form of this multiplexing method utilizes oblique input angles to generate ring-like spatial modes within the optical fiber core. This radial based spatial multiplexing (rSDM) is compatible with single core fibers and conventional optical fiber systems. As rSDM has been shown to be independent of wavelength, rSDM channels allow for adaption of wavelength division multiplexing, and has been experimentally shown to be capable of improving optical fiber data rates by at least an order of magnitude. Current research into rSDM …