Engineering Commons^™

Multiple Agent Target Tracking In Gps-Denied Environments, Skyler Tolman

Theses and Dissertations

Unmanned aerial systems (UAS) are effective for surveillance and monitoring, but struggle with persistent, long-term tracking, especially without GPS, due to limited flight time. Persistent tracking can be accomplished using multiple vehicles if one vehicle can effectively hand off the tracking information to another replacement vehicle. This work presents a solution to the moving-target handoff problem in the absence of GPS. The proposed solution (a) a nonlinear complementary filter for self-pose estimation using only an IMU, (b) a particle filter for relative pose estimation between UAS using a relative range (c) visual target tracking using a gimballed camera when the …

Analysis Of Applied Modifications To A Cone Penetration Test-Based Lateral Spread Displacement Prediction Model, Alexander Edward Corob

Theses and Dissertations

This study set out to examine the effectiveness and reliability of six modifications to the Zhang et al. (2004) CPT-based lateral spread model. A regression analysis, distribution charts, and a discriminant analysis are performed to determine how effective the modifications are on the model. From the comparisons and statistical analysis performed in this study, application of these modifications reduces over-predictions from strain-based prediction methods. Unfortunately, the tendency to under-predict displacements on average is also increased.

Bending Behavior Of Concrete Beams With Fiber/Epoxy Composite Rebar, Kolten Dewayne Rice

Theses and Dissertations

This research explores the use of carbon/epoxy and fiberglass/epoxy fiber-reinforced polymer (FRP) composite rebar manufactured on a three-dimensional braiding machine for use as reinforcement in concrete beams under four-point bending loads. Multiple tows of prepreg composite fibers were pulled to form a unidirectional core. The core was consolidated with spirally wound Kevlar fibers which were designed to also act as ribs to increase pullout strength. The rebar was cured at 121â—¦C (250â—¦F) in an inline oven while keeping tension on the fibers. Five configurations of reinforcing bars were used in this study as reinforcement in concrete beam specimens: carbon/epoxy rebar …

Characterization And Modeling Of The Martensite Transformation In Advanced High-Strength Steels, Stephen Roy Cluff

Theses and Dissertations

Multiple studies on the microstructures of advanced high-strength steels are presented here that seek to add to the already substantial body of knowledge on martensite in steel. These studies seek to gain additional insight into the role that the martensite transformation has on the observed mechanical properties of modern steels. Crystallographic Reconstruction of Parent Austenite Twin Boundaries in a Lath Martensitic Steel The study of post-transformation microstructures and their properties can be greatly enhanced by studying their dependence on the grain boundary content of parent microstructures. Recent work has extended the crystallographic reconstruction of parent austenite in steels to include …

Machine Learning On Acoustic Signals Applied To High-Speed Bridge Deck Defect Detection, Yao Chou

Theses and Dissertations

Machine learning techniques are being applied to many data-intensive problems because they can accurately provide classification of complex data using appropriate training. Often, the performance of machine learning can exceed the performance of traditional techniques because machine learning can take advantage of higher dimensionality than traditional algorithms. In this work, acoustic data sets taken using a rapid scanning technique on concrete bridge decks provided an opportunity to both apply machine learning algorithms to improve detection performance and also to investigate the ways that training of neural networks can be aided by data augmentation approaches. Early detection and repair can enhance …

An Exploration Of Neural Networks In Enhanced Resolution Remote Sensing Products, Jordan Paul Brown

Theses and Dissertations

Scatterometry and radiometry are used to obtain measurements of Earth properties with extensive spatial coverage at daily or near-daily temporal resolution. Their measurements are used in many climate studies and weather applications, such as iceberg tracking, ocean wind estimation, and volumetric soil moisture measurements. The spatial resolution of these data products ranges from a few kilometers to tens of kilometers. Techniques to enhance the spatial resolution of these products help reveal finer scale features, but come at the cost of increased noise. This thesis explores the application of neural networks as a possible method to handle the noise and uncertainty …

Near-Coastal Ultrahigh Resolution Scatterometer Winds, Nolan Lawrence Hutchings

Theses and Dissertations

RapidScat 2.5 km ultrahigh resolution (UHR) wind estimation is introduced and validated it in near-coastal regions. In addition, this thesis applies direction interval retrieval techniques and develops a new wind processing method to enhance the performance of RapidScat UHR wind estimation in the nadir region. The new algorithm is validated with L2B wind estimates, Numerical Weather Prediction (NWP) wind products, and buoy measurements. The wind processing improvements produce more spatially consistent UHR winds that compare well with the wind products mentioned above. Hawaii regional climate model (HRCM), QuikSCAT, and ASCAT wind estimates are compared in the lee of the Big …

Vertical Electrical Impedance Measurements Of Concrete Bridge Decks, Jared Scott Baxter

Theses and Dissertations

This research focuses on the creation, validation, automation, and deployment of a nondestructive vertical electrical impedance (VEI) bridge deck assessment apparatus. A multichannel impedance analyzer with a moving platform is developed that can assess the deterioration state of a bridge deck without stationary traffic control. The multichannel apparatus is capable of taking over 500 impedance samples a second and can scan a bridge deck over 500 times faster than more traditional techniques. This research also shows VEI measurements are inversely proportional to the diffusivity of ions through concrete and that an impedance measurement frequency of 25 kHz is the most …

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 …

Pilot-Scale Test Of Water Wash Carbon Dioxide Absorption System For Purifying Landfill Gas At Jones Island Wastewater Reclamation Facility, Rebecca Schruender

Theses and Dissertations

Biogas, a product of the digestion of organic material, consists primarily of methane and carbon dioxide. By purifying raw biogas, or removing the carbon dioxide, it can be upgraded to biomethane, which can be used to generate heat and electricity or as a substitute for natural gas. An effective method of biogas purification is the water wash process, which consists of an absorption column in which a stream of biogas runs counter-current to a stream of water. The carbon dioxide dissolves in the water, increasing the methane concentration of the gas. A pilot scale system was operated at Jones Island …

A Game Modeling Of A Closed-Loop Supply Chain In A Water-Energy Nexus: Technology Advancement, Market Competition And Capacity Limit, Nabeel Hamoud

Theses and Dissertations

Water and energy are two scarce and concerning resources interconnected in the water-energy nexus. In the nexus, production of energy needs water, and production of water needs energy. For better management of these resources in the nexus, this research considers a supply chain that consists of water suppliers, power suppliers, and consumers of these commodities. In the chain, water suppliers purchase power from power suppliers, and power suppliers purchase water from water suppliers. Other consumers can also buy these resources at the water and power markets. Each firm tries to maximize its own profit. The suppliers of water and power …

A Systematic Approach For Automatically Answering General-Purpose Objective And Subjective Questions, Lok Prasad Acharya

Theses and Dissertations

In this era of information explosion, people generally rely on the Internet, and more precisely, the search engines to get answers to their questions. However, what a search engine can do is just retrieve documents. Given some keywords, it only returns the relevant ranked documents that contain the keywords. Although users often want a precise answer to a question, they are left to extract answers from the documents themselves. This is where Automatic Question Answering (AQA) systems come into play. An AQA system takes questions in natural language as input and searches related answers in the set of documents and …

Effects Of Resampled Data On Time Series Forecasting Accuracy, Jennifer Garland

Theses and Dissertations

This thesis will look at time series forecasting of the air pollutants in Beijing, China and the power consumption of an individual household located in Sceaux, France. The forecast will be taken from two classical methods, the Holt-Winters’ methods and the Seasonal Autoregressive Integrated Moving Average (SARIMA) method. The Holt-Winters’ method will be looked at from the additive, multiplicative and damped methods. The SARIMA model will be looked at as a uni-variate model. In this thesis, it will be shown that less complex algorithms, such as the Holt-Winters’ methods can process larger data sets without the need of resampling, and …

Improving Grapheme-To-Phoneme Translation With The Use Of Nalu Attention Mechanisms, Brian Sheldon Smith

Theses and Dissertations

In recent years, Natural Language Processing in the field of machine learning has seen some major improvements. Data scientists have shown that neural networks are capable of breaking down semantics of sentences, translating languages, and answering complex questions with fast recall. While impressive, these feats all hinge on having access to a massive amount of clean text, or data sets with almost perfect grammar and spelling. Without this, neural networks will usually fail to converge on a meaningful result. To partially this dependency, Grapheme-to-Phoneme conversion can be employed. This is the conversion of words from their spellings to a form …

Deep Learning Models For Visibility Forecasting, Luz Carolina Ortega Gomez

Theses and Dissertations

This dissertation addresses the task of visibility forecasting via deep learning models using data from weather stations. Visibility is one of the most critical weather impacts on transportation systems. Low visibility conditions can seriously impact safety and traffic operations, leading to adverse scenarios, causing accidents, and jeopardizing transportation systems. Accurate visibility forecasting plays a key role in decision-making and management of transportation systems. However, due to the complexity and variability of weather variables, visibility forecasting remains a highly challenging task and a matter of significant interest for transportation agencies nationwide. This dissertation explores the use of deep learning models for …

An Application Of Clustering And Cluster Update Methods To Boiler Sensor Prediction And Case-Based-Reasoning To Boiler Repair, Timothy Edward Rooney

Theses and Dissertations

Driven by demand from both consumers and manufacturers alike, Internet of Things (IoT)

capabilities are being built into more products. Consumers want more control and access to their

devices, while manufacturers can find data gathered from IoT-capable products invaluable. In

this thesis, we use data from a growing fleet of IoT-connected boilers in the residential, lightcommercial, and medium-commercial ranges to demonstrate a framework for cluster initialization

and updating. We compare two methods of dynamically updating clusters: a sequential method

inspired by sequential K-means clustering and a cohesion-based method called DYNC. A predictive

artificial neural network system demonstrates the effectiveness of …

Surface Alloying Of Mild Steel During Casting Process: Microstructural Evolution, Phase Development And Heat Treatment, Kaustubh Kishore Rane

Theses and Dissertations

Casting is one of the oldest manufacturing processes in practice and the growth of casting industry through the ages has led to scientific leaps in the field of metallurgy. As we look into the history of metal castings, it is prominent that a steady growth in the knowledge leading to rise of newer casting techniques has caused an exponential increase in the way we can use metal castings to improve our lives. The surface alloying of mild steel to compositions targeted towards stainless steel compositions was performed in this study by sand casting process. Sand casting is one of the …

Experimental, Theoretical And Numerical Evaluation Of Wicking Models For Liquid Imbibition In Dry Porous Wicks, Mohammad Amin Faghihi Zarandi

Theses and Dissertations

Nowadays commercial wicks are utilized by consumer product companies in several important commercial applications including Tiki® Brand torches, the passive lubricants of machine gears, propellant management device, and fragrance dispersion units. Spontaneous imbibition of a liquid into porous wicks, also called wicking, is modeled using the single-phase Darcy’s law after assuming a sharp flow-front marked by full saturation behind the front. An analytical expression for the height of the wicking flow-front as a function of time is tested through comprehensive experiments using different wicks and an oil as the wicking liquid. We proposed a model based on sharp liquid-front where …

Assessment Of Sensory Abnormalities In Children With Asd Using Virtual Reality, Ankit Koirala

Theses and Dissertations

Sensory abnormality is one of the important characteristics of Autism Spectrum Disorder(ASD). A large number of studies suggest a strong connection between sensory abnormalities and ASD. Therefore, it is important to assess sensory abnormalities for diagnosis and intervention of ASD. In this thesis study, we aim to develop a virtual reality system that can measure sensory abnormalities in adolescents with ASD. Sensory abnormalities can affect all five senses: touch, vision, smell, taste and auditory. However, in this study, we focus on assessing sensory abnormality in vision and touch sensory processing. Twelve adolescents with ASD and 12 typically developing (TD) adolescents …

Exploring Methods For Studying Recoverability Of Shipboard Electrical Power Distribution Systems, Jacob David Gudex

Theses and Dissertations

Advancement of the technology included on ships, is changing the nature of loads installed on ships. Not only are there more loads than installed power generation, but advanced electrically powered weapons and sensors are changing the profile of the installed loads. These are challenges for future shipboard power systems design. Challenges which must be solved with careful distribution system planning, energy storage integration, and selection of individual power electronic converters within the ship. Different topologies and distribution systems have differing fault isolation and recovery (FIR) capability sets, which affects ship survivability. Furthermore, different FIR capability sets, operate at different speeds. …

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, …

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 …

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. …

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.

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 …

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 …

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 …

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 …