Engineering Commons^™

Scatterometer Cross Calibration Using Volume Scattering Models For Amazon Rainforest Canopies, Evan Neil Chrisney

Theses and Dissertations

Spaceborne scatterometers have measured the normalized radar cross section (RCS) of the earth's surface for several decades. Two frequencies, C- and Ku-band, have been used in designing scatterometers, such as with the Ku-band NASA Scatterometer (NSCAT) and the C-band Advanced Scatterometer (ASCAT). The scatterometer data record between C- and Ku-band has been disjoint for several decades due to the difficulties in cross calibration of sensors that operate at different frequencies and incidence angles. A model for volume scattering over the Amazon rainforest canopy that includes both the incidence angle and frequency dependence is developed to overcome this challenge in cross …

Splice Performance Of #6 Reinforcing Bars In Masonry With Self-Consolidating Grout, Annie Ruth Nielson

Theses and Dissertations

Reinforced masonry grouted using self-consolidating grout (SCG) is a relatively new and economically competitive option for construction, providing advantages such as reduced construction time, decreased noise and vibration, and reliable consolidation. However, SCG has different properties than conventional grout and its performance should be verified using current governing code requirements. The purpose of this research program was to determine the development length of spliced reinforcing bars in masonry grouted with SCG.Twelve masonry panels, four courses high and two and a half blocks wide, were constructed using 8-inch concrete masonry units, each with two pairs of vertically spliced #6 reinforcing bars. …

Evaluating The Resiliency Of Industrial Internet Of Things Process Control Using Protocol Agnostic Attacks, Hector L. Roldan

Theses and Dissertations

Improving and defending our nation's critical infrastructure has been a challenge for quite some time. A malfunctioning or stoppage of any one of these systems could result in hazardous conditions on its supporting populace leading to widespread damage, injury, and even death. The protection of such systems has been mandated by the Office of the President of the United States of America in Presidential Policy Directive Order 21. Current research now focuses on securing and improving the management and efficiency of Industrial Control Systems (ICS). IIoT promises a solution in enhancement of efficiency in ICS. However, the presence of IIoT …

Mathematical Model, Simulated Design And Experimental Results For Parabolic Mirror Based Multiplexer For Spatially Multiplexed Fiber Optic Communication Systems, Ce Su

Theses and Dissertations

Spatial Domain Multiplexing (SDM) is a multi-input multi-output (MIMO) architecture. It adds an innovative dimension to optical fiber communication systems by enabling spatial reuse of the optical frequencies. SDM utilizes radially distributed spatial locations for different input signals based on their input launch angles. These input channels propagate in a helical path inside the carrier fiber. These SDM input channels do not encounter any perceptible cross-talk or inter-symbol interference. The SDM system is similar to other optical communication systems. However, they require two added parts. These parts are the spatial multiplexer, also known as the Beam Combiner Module (BCM) and …

Runway Incursions: Examining Airport Managers’ Perspectives Of The Challenges Related To Vehicle/Pedestrian Deviations, John Arthur Mahlman Jr.

Theses and Dissertations

The purpose of the current study was twofold: (a) to describe the contributing factors of vehicle and pedestrian deviation (V/PD) runway incursions (RIs) nationally, and (b) to describe what mitigation approaches/strategies airport managers recommend or find to be effective. The current study used a content analysis in identifying airports with more than 10 V/PD RIs within Fiscal Years (FY) 2011 to FY 2016. After the study population was identified, phenomenological design was used to poll airport executives of the previously identified airports. The 11 participants elected to either complete an anonymous survey or participate in a telephone interview. Spradley’s (2016) …

Electronic Word-Of-Mouth (Ewom): Examining The Relationship Between Factors Influencing Ewom Activities And Passengers’ Purchasing Involvement In The Context Of Aviation, Ratchada Ruenruoy

Theses and Dissertations

The purpose of the study was manifold: (a) to examine the relationship a set of targeted factors has on electronic Word-of-Mouth (eWOM) activities in the context of aviation, (b) to examine the extent to which these factors affect airline passengers’ purchasing involvement, and (c) to determine the extent to which eWOM activities mediate the relationship between the targeted factors and purchasing involvement. Research factors included (a) purchasing perceptions, which consisted of satisfaction, loyalty, perceived value, and service quality; (b) social environment, which consisted of age, gender, and cultural differences relative to Hofstede’s (1980) cultural dimensions; and (c) experiences, which consisted …

Evaluation Of The Most Significant Factors Influencing The Production Rates Of Highway Construction Activities, Angelica M. Neira

Theses and Dissertations

The utilization of realistic production rates is key for the accurate estimation of the contract time in highway projects. Several factors have an impact on production rates and change the total duration of construction projects. To organize and complete projects in a timely, quality and financially responsible manner, projects need to be scheduled carefully. Schedulers and planners of the Texas Department of Transportation (TxDOT) have been noticing that the estimated timelines are far from the reality and want to investigate if external factors can be the cause of this discrepancy. Some of the factors considered in this study are the …

An Advanced Approach For Contract Time Determination In Highway Projects, Cuauhtemoc Torres Cantu

Theses and Dissertations

In project management, finishing a project on schedule is one of the most important aspects. The Texas Department of Transportation (TxDOT) has been experiencing delays in some projects that can be accounted to an inaccurate project time estimation process. This research presents the development of a user-friendly and comprehensive computer-based contract time determination system. The enhanced system implements probabilistic scheduling techniques such as Program Evaluation and Review Technique, and Monte Carlo Simulation. Additionally, the application of a lognormal two-point PERT method is explored in this study. The new system proposes the use of a database of production rates based on …

Improving Hydroshare And Web Application Interoperability Through Integrated Gis And His Data Services, Kenneth Jack Lippold

Theses and Dissertations

HydroShare is a collaborative online system being developed by the Consortium of Universities for the Advancement of Hydrologic Science Inc. (CUAHSI) with the goal of facilitating the dissemination, visualization, and publishing of hydrologic data and models. External web applications serve a key role in extending HydroShare's capabilities, so robust application programming interfaces (APIs) are a vital component of HydroShare's architecture. Hydrologic data stored on HydroShare are defined by a data type, and much of these data are either geospatial or time series data. Although HydroShare's API provides ways to upload and download files, as well as access certain metadata, it …

Investigation Of Electrocoating Mechanisms, Tyler James Marlar

Theses and Dissertations

The objective of this work is to advance the mechanistic understanding of cathodic electrocoating. These efforts are focused on the initial processes responsible for deposition, which are examined through direct experimentation and simulation. Electrocoating is a global industrial process providing a corrosive resistant base paint to automobile bodies. Presently, empirical models are used to model coating thickness; these models tend to overpredict deposition in occluded areas. Convection is implemented to study the behavior of adhered surface H2 bubbles on the substrate surfaces. The impact of surface H2 bubbles and early e-coat deposition on the local current density is studied using …

Variance Reduction In Wind Farm Layout Optimization, Bertelsen Gagakuma

Theses and Dissertations

As demand for wind power continues to grow, it is becoming increasingly important to minimize the risk, characterized by the variance, that is associated with long-term power forecasts. This thesis investigated variance reduction in power forecasts from wind farm layout optimization.The problem was formulated as a multi-objective optimization one of maximizing mean-plant-power and minimizing variance. The ε−constraint method was used to solve the bi-objectiveproblem in a two-step optimization framework where two sequential optimizations are performed. The first is maximizing mean wind farm power alone and the second, minimizing variance with a constraint on the mean power which is the value …

Trajectory Optimization And Design For A Large Number Of Unmanned Aerial Vehicles, Jenna Elisabeth Newcomb

Theses and Dissertations

An unmanned aerial vehicle (UAV) swarm allows for a more time-efficient method of searching a specified area than a single UAV or piloted plane. There are a variety of factors that affect how well an area is surveyed. We specifically analyzed the effect both vehicle properties and communication had on the swarm search performance. We used non-dimensionalization so the results can be applied to any domain size with any type of vehicle. We found that endurance was the most important factor. Vehicles with good endurance sensed approximately 90% to 100% of the grid, even when other properties were lacking. If …

Enabling Compact Devices Through Origami And Developable Mechanisms, Jacob Ryan Greenwood

Theses and Dissertations

This thesis provides resources that enable the design of novel and compact mechanical devices by providing terminology, engineering models, and design methods in the fields of developable mechanisms and origami-based engineering.The first part of this work presents engineering models to aid in the design of cylindrical developable mechanisms. These models take into account the added spatial restrictions imposed by the developable surface. Equations are provided for the kinematic analysis of cylindrical developable mechanisms. A new classification for developable mechanisms is also presented (intramobile, extramobile, and transmobile) and two graphical methods are provided for determining this classification for single-DOF planar cylindrical …

Characterization Of Local Void Content In Carbon Fiber Reinforced Plastic Parts Utilizing Observation Of In Situ Fluorescent Dye Within Epoxy, Wyatt Young Warner

Theses and Dissertations

Experimentation exploring the movement of voids within carbon fiber reinforced plastics was performed using fluorescent dye infused into the laminates observed through a transparent mold under ultraviolet light. In situ photography was used as an inspection method for void content during Resin Transfer Molding for these laminates. This in situ inspection method for determining the void content of composite laminates was compared to more common ex-situ quality inspection methods i.e. ultrasonic inspection and cross-section microscopy. Results for localized and total void count in each of these methods were directly compared to test samples and linear correlations between the three test …

Application Of Solar Water Heaters For Industrial Use, Lucas T. Atkins

Theses and Dissertations

Solar water heating is a technology that is mainly used for domestic water heating in residential homes. In most applications, the idea is to make a home “off the grid” in that there is no requirement for outside infrastructure or need for energy utility to provide power to this home. This falls in line with the trend of “going green” in an effort to reduce energy use, increase efficiency, or reduce emissions and other harmful byproducts.

This technology can be adapted to reduce the energy costs of industrial manufacturing plants. By eliminating the need for certain sections of a process …

Graphene-Fibers Hybrid Structures As Adsorbents For Heavy Metal Ions In Aqueous Solutions, Dulce C. Capitanachi

Theses and Dissertations

The project focuses on the study of graphene-fiber hybrid structures for adsorption of heavy metal ions in aqueous solutions. Polyvinyl alcohol-based graphene–fiber structures were created using centrifugal spinning and a carbonization process.

Characterization methods of the graphene–fiber hybrid structures (GFHS) include SEM, FTIR, TGA, and EDX. Single-step batch-type adsorption studies were performed to analyze the interaction of Cu (II) and Pb (II) ions onto GFHS surface. Different heavy metal ion concentrations were used, as well as a variation of pH values. Elemental analysis of the adsorbent’s surface after filtration experiments was studied by EDX and spectroscopy to verify the presence …

Design And Testing Of A Modular Laser System With Laser Machining And Bioprinting Capabilities, Jesus Gonzalez

Theses and Dissertations

This thesis introduces the applications of ultrafast lasers while focusing on their bioprinting capabilities. A custom system was designed to utilize a femtosecond laser for 2D and 3D applications. The characteristics of lasers allow them to be efficiently used in machining, 3D printing, research, and more. Their power and precision allow them to be used for delicate work such as bioprinting. Bioprinting is a field holding great potential to benefit society. Studies conducted over the years prove its usefulness in printing cells and biomaterials, while showing there is still much to improve upon before being able to print fully functioning …

Uncertainty And Error In Combat Modeling, Simulation, And Analysis, Jason A. Blake

Theses and Dissertations

Due to the infrequent and competitive nature of combat, several challenges present themselves when developing a predictive simulation. First, there is limited data with which to validate such analysis tools. Secondly, there are many aspects of combat modeling that are highly uncertain and not knowable. This research develops a comprehensive set of techniques for the treatment of uncertainty and error in combat modeling and simulation analysis. First, Evidence Theory is demonstrated as a framework for representing epistemic uncertainty in combat modeling output. Next, a novel method for sensitivity analysis of uncertainty in Evidence Theory is developed. This sensitivity analysis method …

Development Of A Gpu-Based Real-Time Interference Mitigating Beamformer For Radio Astronomy, Jeffrey M. Nybo

Theses and Dissertations

Radio frequency interference (RFI) mitigation enables radio astronomical observation in frequency bands that are shared with many modern satellite and ground based devices by filtering out the interference in corrupted bands. The present work documents the development of a beamformer (spatial filter) equipped with RFI mitigation capabilities. The beamformer is intended for systems with antenna arrays designed for large bandwidths. Because array data post processing on large bandwidths would require massive memory space beyond feasible limits, there is a need for a RFI mitigation system capable of doing processing on the data as it arrives in real-time; storing only a …

Exploring The Efficiency Of Software-Defined Radios In 3d Heat Mapping, Andrew Scott Thomas

Theses and Dissertations

A common method of connecting to the internet is a wireless network. These networks can be monitored to discover the area of their coverage, but commercial receivers don't always provide the most accurate results. A software-defined radio was programmed to sniff wireless signals and tested against a commercial receiver and the results were compared. The results suggest that the software-defined radio performs at least as well as the commercial receiver in distance measurements and significantly better in samples taken per minute. It was determined that the software-defined radio is a viable replacement for a commercial receiver in 3D heat mapping.

Advanced Techniques For Carbon Nanotube Templated Microfabrication, Jason Matthew Lund

Theses and Dissertations

Carbon nanotube templated microfabrication (CNT-M) is a term describing a grouping of processes where carbon nanotubes (CNTs) serve a structural role in the fabrication of a material or device. In its basic form, CNT-M is comprised of two steps: produce a template made from carbon nanotubes and infiltrate the porous template with an additional material. Vertically aligned carbon nanotube (VACNT) templates can be grown to heights ranging from microns to millimeters and lithographically patterned to a desired form. Deposition of an existing thin film material onto a CNT template will coat all template surfaces and can produce a near solid …

A Soft-Error Reliability Testing Platform For Fpga-Based Network Systems, Hayden Cole Rowberry

Theses and Dissertations

FPGAs are frequently used in network systems to provide the performance and flexibility that is required of modern computer networks while allowing network vendors to bring products to market quickly. Like all electronic devices, FPGAs are vulnerable to ionizing radiation which can cause applications operating on an FPGA to fail. These low-level failures can have a wide range of negative effects on the performance of a network system. As computer networks play a larger role in modern society, it becomes increasingly important that these soft errors are addressed in the design of network systems.This work presents a framework for testing …

Maverick: A Stand-Alone Cad Flow For Partially Reconfigurable Fpga Modules, Dallon Godfrey Glick

Theses and Dissertations

Circuit designs for field-programmable gate arrays (FPGAs) are typically compiled by FPGA vendor tools, such as Xilinx's Vivado Design Suite. In recent years, partial reconfiguration (PR) has emerged as a popular technique that allows portions of an FPGA to be dynamically reconfigured after the complete device has been configured with an initial bitstream. However, the nature of current FPGA vendor tools limits further innovation and possible usage models of PR.This thesis presents Maverick, an open-source proof-of-concept computer-aided design (CAD) flow for generating reconfigurable modules (RMs) which target PR regions in FPGA designs. Maverick builds upon existing open source tools (Yosys, …

A New Qpcr Assay To Detect Geosmin-Producing Cyanobacteria, Shane Brian Davis

Theses and Dissertations

Taste-and-odor (T&O) compounds are frequently produced by cyanobacterial blooms in bodies of water. Geosmin, perhaps the most common T&O compound produced by these blooms, is not effectively removed by conventional water treatment processes and frequently causes the tap water to have an off flavor. Although geosmin is not harmful when ingested, it damages the consumers' confidence in the cleanliness of their water. There are treatment options for geosmin removal, but the most common methods are often not implemented until complaints are made by consumers.There has been an increasing amount of research on the use of polymerase chain reaction (PCR)-based methods …

Durability Of Hybrid Large Area Additive Tooling For Vacuum Infusion Of Composites, Nathan Joseph Northrup

Theses and Dissertations

The purpose of this research was to scientifically validate potential cost-saving measures for production of large area additively manufactured tooling for vacuum infusion of composites. These cost saving measures included using a hybrid additive/subtractive manufacturing system to fabricate the mold, requiring lower capital cost and creating shorter lead times. Fiberglass reinforcement was used instead of carbon in the mold material. The validation was done by designing and fabricating a mold for a custom test artifact and analyzing the surface geometry over the course of multiple infusions until tool failure.After printing and machining, the mold required a sealer in order to …

Design Optimization For A Compliant,Continuum-Joint, Quadruped Robot, Vallan Gray Sherrod

Theses and Dissertations

Legged robots have the potential to cover terrain not accessible to wheel-based robots and vehicles. This makes them better suited to perform tasks, such as search and rescue, in real-world unstructured environments. Pneumatically-actuated, compliant robots are also more suited than their rigid counterparts to work in real-world unstructured environments with humans where unintentional contact may occur. This thesis seeks to combine the benefits of these two type of robots by implementing design methods to aid in the design choice of a 16 degree of freedom (DoF) compliant, continuum-joint quadruped. This work focuses on the design optimization, especially the definition of …

Investigating The Effects Of Altitude And Flap Setting On The Specific Excess Power Of A Pa-28-161 Piper Warrior, Tjimon Meric Louisy

Theses and Dissertations

The high number of General Aviation (GA) accidents attributed to Loss of Control suggests that GA pilots are lacking low speed awareness and are unable to appropriately recognize when the aircraft is in a low energy state. There is, therefore, an urgent need for the development of an energy management system which is applicable to GA aircraft that can alert the pilot in situations of low energy conditions and recommends to the pilot the appropriate corrective action to restore conditions to a safe energy state. This will require the development of an algorithm that governs this energy management system that …

Home Automation System By Voice Commands, Noor Kamil Abdalhameed

Theses and Dissertations

The Home Automation System is one of the most important technologies that are used by humans for controlling electrical devices to reduce manual efforts in their daily tasks. The home automation system by voice has the ability to understand thousands of voice commands and perform the required action to control various electrical devices. The voice recognition is a bit complex and challenging task since each person has his accent. Therefore, Bitvoicer Server used in the home automation system in this thesis since it supports 17 languages from 26 countries and regions, and has the ability to recognize an unlimited number …

Mitigating Pilot Contamination Through Optimizing Pilot Allocation In Massive Mimo Systems, Rand Abdul Hussain

Theses and Dissertations

This dissertation has proposed several algorithms to optimize the allocation of pilots to the users’ equipment (UEs) to mitigate the effect of the pilot contamination problem in the massive MIMO systems. Pilot contamination reduces the performance of massive MIMO systems due to the reduction in the quality of the estimated channel between a UE and the serving base station (BS). The limitation of the number of samples in a coherence block limits the number of unique mutually orthogonal pilots, and hence, reusing the set of pilots across the cells causes inter-cell interference during pilot transmission, which is called pilot contamination. …

Socialization Of Veterans Using Virtual Reality, Joan M. Savage

Theses and Dissertations

Virtual reality, augmented reality, mixed reality, and video games are growing in popularity and fulfilling genuine human needs that the real world is currently unable to satisfy. Games are providing rewards that reality is not. They are teaching and inspiring and engaging us in ways that reality is not (McGonigal, 2011). The purpose of this study was to capture the essence of socialization in virtual reality as a Ph.D. dissertation topic at Florida Institute of Technology - Human-Centered Design. This study used a phenomenology methodology to capture the experiences of beneficial features of players who use virtual reality. The study …