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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

Underwater Particle Image Velocimetry (Piv) Measurement Of Turbulence Over Mussel Bed In A Deepsite Of Lake Michigan, Tong Jin

Theses and Dissertations

The influence of the benthic filter feeders, such as bivalves, on ecosystem plankton, and nutrient dynamics is considered significant in shallow marine and freshwater systems. Recent indirect evidence showed that the profundal quagga mussels (Dreissena rostriformis bugensis) have fundamentally altered energy flow and dynamics of nutrients and phytoplankton in Lake Michigan and other Great Lakes. To investigate the phytoplankton grazing rate of the quagga mussel and the mussel siphon currents induced bio-mixing, a self-contained in situ Underwater Particle Image Velocimetry was developed to measure the turbulence structure and the turbulent diffusion coefficient immediately above the profundal quagga mussel covered substrate …

Optimizing Hydrogen Sulfide Removal And Biogas Production Using The Water Wash Method, Brian Leightner

Theses and Dissertations

Biogas forms from decomposing organic material in agricultural digesters, landfills, and wastewater treatment plant digesters. Biogas is mostly composed of methane, and can be used as a carbon-based fuel. Microorganisms that consume organics in these waste streams also produce hydrogen sulfide (H2S) as part of the biogas, in varying trace amounts. H2S is corrosive to engines and pipes for machinery, a human health hazard when inhaled, and an aquatic hazard when dissolved in water. Water washing is an absorption process that dissolves hydrogen sulfide and other water soluble compounds in this process and carries it away from the gas, thereby …

Application Of Survival Analysis Techniques To Probabilistic Assessment Of Fatigue In Steel Bridges, Azam Nabizadehdarabi

Theses and Dissertations

The fatigue of engineering materials under repetitive loading is a significant issue affecting the design and durability of components and systems in a variety of engineering-related applications including civil, mechanical, aerospace, automotive, and electronics. Many factors can affect the service life of a component or system under repetitive loading, such as the type of structure, loading, connection details, stress state, peak stress or stress range, surface condition, temperature, and environmental exposure. Currently, there is no comprehensive probabilistic approach that can systematically address all the factors that contribute to fatigue on a single mathematical platform. However, advanced analysis techniques developed for …

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 …

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. …

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 …

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 …

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 …

Single Photon Avalanche Diode (Spad) Array Quenching And A Novel Quantum Random Number Generator (Qrng), Mano Rahul Kumar Pakalapati

Theses and Dissertations

Single Photon Avalanche Diodes, SPADs is a single-photon sensitive light detector with capabilities of pico-second timing resolutions and offer potential for enhancing various fields of science to evolve into quantum-age. SPAD has applications ranging from quantum computing, cryptography (QKD) to applications in medicine such as neural imaging and Single Photon Emission Computed Tomography (SPECT). SPAD arrays are gaining popularity as they enable for parallel photon detection and 3D imaging. To account for the process tolerances and aging, each SPAD-pixel needs a tunable quenching circuit in the frontend for post-fabrication fine-tuning, this research work presents a novel Dual Triggered Tunable Active …

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 …

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 …

Numerical Simulations Of Comprehensive Hydrodynamic Performance Of Darpa Suboff Submarine, Kenshiro Takahashi

Theses and Dissertations

A numerical study of the DARPA SUBOFF model using computational fluid dynamics (CFD) has been presented for developing a CFD application procedure to compute the hydrodynamic performance of underwater vehicles, including submarines. Several configurations, such as bare hull, fairwater, sterns, and/or ringwing-appended hulls, were examined for the straight-ahead, steady translation and turning, and self-propelled conditions. A systematic study was conducted to ensure an adequate computational domain expansion and reasonable prism layer mesh properties for solutions independent of the parameters. The hydrodynamic forces exerted on the hull and the appendages were verified and validated in accordance with a published methodology under …

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 …