Engineering Commons^™

An Arithmetic-Based Deterministic Centroid Initialization Method For The K-Means Clustering Algorithm, Matthew Michael Mayo

Theses and Dissertations

One of the greatest challenges in k-means clustering is positioning the initial cluster centers, or centroids, as close to optimal as possible, and doing so in an amount of time deemed reasonable. Traditional fc-means utilizes a randomization process for initializing these centroids, and poor initialization can lead to increased numbers of required clustering iterations to reach convergence, and a greater overall runtime. This research proposes a simple, arithmetic-based deterministic centroid initialization method which is much faster than randomized initialization. Preliminary experiments suggest that this collection of methods, referred to herein as the sharding centroid initialization algorithm family, often outperforms random …

An Exploration Of Rule Clustering In Cellular Automata Rule Spaces, Jordon Huffman

Theses and Dissertations

The study of complex systems examines the global behavior of a system and how the individual parts of the system affect that behavior [1]. The study of complex systems spans across many fields of science like biology, physics, engineering, and computer science. One area of complex systems that has not been fully explored is cellular automata. Since its discovery by John von Neumann, there have been no consistent ways of categorizing similarities between cellular automata rules or collecting similar rules for observation. This thesis introduces an approach to identifying clusters of similar rules and extracting rules from that cluster. Several …

Experimental, Numerical, And Analytical Slosh Dynamics Of Water And Liquid Nitrogen In A Spherical Tank, Jedediah Morse Storey

Theses and Dissertations

Understanding, predicting, and controlling fluid slosh dynamics is critical to safety and improving performance of space missions when a significant percentage of the spacecraft’s mass is a liquid. Computational fluid dynamics simulations can be used to predict the dynamics of slosh, but these programs require extensive validation. Many experimental and numerical studies of water slosh have been conducted. However, slosh data for cryogenic liquids is lacking. Water and cryogenic liquid nitrogen are used in various ground-based tests with a spherical tank to characterize damping, slosh mode frequencies, and slosh forces. A single ring baffle is installed in the tank for …

A Method To Enhance The Heat Transfer Mechanism In Metal Particle Porous Beds With Applicability To Paramagnetic Materials For Hydrogen Storage, Shahin Shafiee

Theses and Dissertations

This research introduces a heat transfer enhancement method for porous beds of either ferromagnetic and paramagnetic materials. Throughout this work, it is shown that applying magnetic fields, not only enhances the heat transfer rate in particle beds but also improves hydrogenation properties of lanthanum nickel. The first section of the work is focused on heat transfer in iron oxide beds under magnetism. This stage studies effect of different magnetic field configurations and intensities on conduction improvement. The second phase of the work, studies the effect of utilizing magnetic fields on hydriding properties of a selected metal hydride. Experimentation has proven …

Ultra Short Mr Relaxometry And Histological Image Processing For Validation Of Diffusion Mri, Amin Nazaran

Theses and Dissertations

Magnetic Resonance Imaging (MRI) is an imaging modality that acquires an image with little to no damage to the tissue. MRI does not introduce foreign particles or high energy radiation into the body, making it one of the least invasive medical imaging modalities. MRI can achieve excellent soft tissue contrast and is therefore useful for diagnosis of a wide variety of diseases. While there are a wide variety of available techniques for generating contrast in MRI, there are still many open areas for research. For example, many tissues in the human body exhibit such rapid signal decay that they are …

Microwire Regenerative Peripheral Nerve Interfaces With Wireless Recording And Stimulation Capabilities, Ali Ajam

Theses and Dissertations

A scalable microwire peripheral nerve interface was developed, which interacted with regenerated peripheral nerves in microchannel scaffolds. Neural interface technologies are envisioned to facilitate direct connections between the nervous system and external technologies such as limb prosthetics or data acquisition systems for further processing. Presented here is an animal study using a handcrafted microwire regenerative peripheral nerve interface, a novel neural interface device for communicating with peripheral nerves. The neural interface studies using animal models are crucial in the evaluation of efficacy and safety of implantable medical devices before their use in clinical studies.16-electrode microwire microchannel scaffolds were developed for …

Lateral Resistance Of H-Piles And Square Piles Behind An Mse Wall With Ribbed Strip And Welded Wire Reinforcements, Andrew I. Luna

Theses and Dissertations

Bridges often use pile foundations behind MSE walls to help resist lateral loading from seismic and thermal expansion and contraction loads. Overdesign of pile spacing and sizes occur owing to a lack of design code guidance for piles behind an MSE wall. However, space constraints necessitate the installation of piles near the wall. Full scale lateral load tests were conducted on piles behind an MSE wall. This study involves the testing of four HP12X74 H-piles and four HSS12X12X5/16 square piles. The H-piles were tested with ribbed strip soil reinforcement at a wall height of 15 feet, and the square piles …

Micro-Ct Inspection Of Impact Damage In Carbon/Epoxy Rods, Lindsey Charlene Cahoon

Theses and Dissertations

Various configurations of unidirectional carbon/epoxy composite rods were impacted radially, inspected using micro-CT scanning equipment, and tested in axial compression to measure the residual strength after impact. This data was used to correlate the relationship between impact energy, residual strength, and the peak crack area and total crack volume along the length of the specimens. These specimens represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® geometries) that are continuously fabricated using advanced three-dimensional braiding techniques. The specimens were radially impacted with 2.5 J (1.9 ft-lbs), 5.0 J (3.7 ft-lbs), 7.5 J (5.6 ft-lbs), …

Computing Research In Academia: Classifications, Keywords, Perceptions, And Connections, Sung Han Kim

Theses and Dissertations

The Association for Computing Machinery (ACM) recognizes five computing disciplines: Computer Science (CS), Computer Engineering (CE), Information Technology (IT), Information Systems (IS), and Software Engineering (SE). Founded in 1947 the ACM is the world's largest society for computing educators, researchers, and professionals. While Computer Science has been a degree program since 1962, the other four are relatively new. This research focuses on understanding the graduate research in four of the five ACM disciplines (CS, CE, IT, and IS) using a large body of thesis and dissertation metadata. SE is not found in the metadata and graduate work in SE is …

Roadway Safety Analysis Methodology, Samuel Thomas Mineer

Theses and Dissertations

The Utah Department of Transportation (UDOT) Traffic and Safety Division continues to advance the safety of the state roadway network through network screening and decision making tools. In an effort to aid UDOT in meeting this goal, the Department of Civil and Environmental Engineering at Brigham Young University (BYU) has worked with the Statistics Department in developing analysis tools for highway safety, specifically the Utah Crash Prediction Model (UCPM) and the Utah Crash Severity Model (UCSM). Additional tools and methodologies, such as the "Hot Spot Identification and Analysis," have been created to summarize the roadway characteristics, crash data, and possible …

Implementation Of Bim In The Municipal Plan Review Process, Liz Shantalle Ricardo Belliard

Theses and Dissertations

Obtaining a building permit is an important step for any construction project. Whether it is for a new construction or a remodel job, the process involves a plan review performed by building officials. The purpose of this research was to explore ways in which Building Information Modeling (BIM) could be used to aid code officials during the plan review process. The objectives of the study were to determine if the level of detail in BIM was complete enough to allow a plan review to be perform accurately, to identify the extent to which architects are comfortable with using their models …

Flight Test Investigation On The Effects Of Aircraft Flap Configuration Change On Longitudinal Trim, Tiziano Bernard

Theses and Dissertations

Loss of Control (LOC) in general aviation has been a topic of extensive study and analysis in the United States and the European Union due to a long series of aircraft accidents in the past decades. The National Transportation Safety Board (NTSB) has identified over 1500 accidents in the traffic pattern involving LOC in general aviation aircraft between 1982 and 2015. LOC has often been attributed to deficiencies in pilot training, and the typical recommendation to reduce the number of accidents is to provide further training in stalls and spins. The European Aviation Safety Agency (EASA) has performed research that …

An Analysis Of Capital Cost Estimation Techniques For Chemical Processing, Omar Joel Symister

Theses and Dissertations

This research serves to compare the use of the capital cost estimation software, Aspen Capital Cost Estimator (ACCE), with other capital cost estimating methods specifically the module costing technique outlined by Richard Turton et al. and also a factorial costing technique outlined by Gavin Towler and Ray Sinnott. This study will compare popular process equipment found in the chemical process industries. The relationship between the capacities of the equipment, as it relates to the cost as well as operational pressures and materials of construction (MOC), will also be obtained and compared. The results of this study may be used by …

Evaluation Of Unbound Pavement Layers Moduli Using The Miniaturized Pressuremeter Test, Alaa Mohammed Shaban

Theses and Dissertations

A small version of pressuremeter known as Miniaturized Pressuremeter (MPMT) was designed and built to provide high quality pavement parameters. The device, which is a modified version of PENCEL Pressuremeter (PPMT) has a 6 inch inflatable probe capable of quickly and reliably measuring the stress-strain response of thin pavement layers. The MPMT stress-strain data can be used as inputs to evaluate existing pavement structures as a part of a pavement management system, and as critical inputs in empirical pavement design methods. To check in-situ operational performance of the new probe, twenty four MPMT and PPMT tests were performed in parallel …

Stiffness Reduction Strategies For Additively Manufactured Compliant Mechanisms, Ezekiel G. Merriam

Theses and Dissertations

This work develops and examines design strategies for reducing the stiffness of 3D-printed compliant mechanisms. The three aspects of a flexure that determine its stiffness are well known: material, boundary conditions, and geometry. In a highly constrained design space however, flexure stiffness may remain unacceptably high even while arriving at the limits of design constraints. In this work, changes to geometry and boundary conditions are examined that lead to drastically reduced stiffness behavior without changing flexure thickness, width, or length. Changes to geometry can result in very complex mechanisms. However, 3D printing enables almost arbitrarily complex geometries. This dissertation presents …

Mitigating Transients And Azeotropes During Natural Gas Processing, Edris Ebrahimzadeh

Theses and Dissertations

Cryogenic carbon capture process can be used to efficiently eliminate CO2 emissions from fossil-fueled power plants. The energy-storing embodiment of cryogenic carbon capture (ES-CCC) integrates energy storage with cryogenic carbon capture and uses natural gas as a refrigerant. ES-CCC captures CO2 from slowly varying or steady-state sources even as it absorbs and replaces large amounts of energy on the grid for energy storage. These large transients occur in the LNG generation as the process moves through energy storing to energy recovery operations. Additionally, raw natural gas often includes CO2 that forms an azeotrope with ethane. Breaking this azeotrope and separating …

Hardware Acceleration For Real Time Atmospheric Turbulence Compensation, Nikhileswar Badri

Theses and Dissertations

Atmospheric turbulence compensation techniques are used to apply filters and to remove noise from the information, such as images. In mission control applications, the processing is required in real time. This thesis focuses on understanding the process and developing architecture for hardware acceleration on the FPGA. Error calculation is a computational extensive component and is a continuous research area to correctly and efficiently measure it in real-time for data processing. The Error is used as a metric to compute the corrected data, such as an image pixel representing the phase, color and intensity to perform image processing. The thesis discusses …

Assessing User Expectations Of Undo In A Multi-User Cad Environment, Jeffrey Eric Nuss

Theses and Dissertations

Undo is a command that users rely on in most software applications. Its importance in multi-user CAD is no different. However, due to its unique nature, users may have different expectations regarding how undo should behave. This research seeks to better understand users' expectations regarding undo in multi-user CAD by having users participate in collaborative design exercises and then asking them how they would expect undo to behave. In addition, users participated in a survey in which they watched 8 videos showing users interacting within multi-user CAD and were then asked about how they would want undo to behave. Based …

Droplet Impingement On Superhydrophobic Surfaces, Cristian Esteban Clavijo Angeles

Theses and Dissertations

This dissertation explores the physics of droplet impingement on superhydrophobic surfaces. The research is divided in three categories. First, the effect of a slip boundary condition on droplet spreading/retracting is considered. A model is developed based on energy conservation to evaluate spreading rates on surfaces exhibiting isotropic and anisotropic slip. The results show that larger slip causes the droplet to spread out farther owing to reduced friction at the interface for both slip scenarios. Furthermore, effects of slip become magnified for large Weber numbers due to the larger solid-liquid contact area during the process. On surfaces with anisotropic slip, droplets …

Google Speech Recognition Using Embedded System, Anita Devi

Theses and Dissertations

This thesis will describe the theoretical background and implementation details of Google Speech Recognition using embedded system. AM37x Evaluation Board developed by Texas Instrument is used as a test bed. All major applications of Google Speech Recognition are covered in this thesis. Also, Evaluation of Google Speech API based on standard dataset is also part of the thesis.

Each implementation details are included with the theoretical background and pre-requisite details:

• Overview of the background of Automatic Speech Recognition Technology.
• Overview of Google Speech Recognition.
• Overview of AM37x Evaluation Module.
• Drivers and Android OS upgradation details.
• Installation of Google pre-requisite Apps …

Characterization Of Quad-Copter Positioning Systems And The Effect Of Pose Uncertainties On Field Probe Measurements, James C. Dossett

Theses and Dissertations

When measuring the Radar Cross Section (RCS) of a test object, many uncertainties must be accounted for, such as the non-homogeneous nature of the medium between the radar test equipment and the platform under test. There are a variety of other error sources, including clutter and Radio Frequency Interference (RFI), motivating the development of techniques to measure and model the uncertainties in RCS measurements. The following research, in unison with prior and current efforts, intends to reduce the impact of these uncertainties by utilizing a unique two-way field probe in the form of a geodesic sphere encompassing a commercial quad-copter …

Electromagnetic Characterization Of Materials Using A Dual Chambered High Temperature Waveguide, Jeffrey S. Sovern

Theses and Dissertations

Measurement of the electromagnetic properties of materials at high temperatures is important for industrial, scientific, medical, and aerospace applications [1]. Current high-temperature electromagnetic material characterization is a time consuming process that typically requires three days to collect data from one material specimen. For example, the standard high-temperature process involving rectangular waveguides [2] requires measurements of the sample (1), the empty waveguide (2), and a metal short standard (3) completed in separate heated runs over three days to perform the Nicolson-Ross-Weir inversion algorithm for computing permittivity and permeability. The technique developed here will reduce the high-temperature measurement process from three days …

A "Big Bang" Versus A "Small Bang" Approach: A Case Study Of The Expeditionary Combat Support System (Ecss) And The Maintenance, Repair, And Overhaul Initiative (Mroi), George B. Lafiguera

Theses and Dissertations

In 2003, the United States Air Force embarked on one of the largest and most comprehensive logistical transformation to delineate the logistics community’s strategy for supporting the warfighter. A key aspect of this campaign plan was to leverage information technology through an enterprise resource planning (ERP) solution called the Expeditionary Combat Support System (ECSS), a “big-bang” approach. In early 2012, the ECSS program was cancelled mainly due to uncontrollable increases in costs and schedule overruns. In late 2012, the Air Force Sustainment Center (AFSC) launched the Maintenance, Repair, and Overhaul initiative (MROi), a “small-bang” approach, to increase enterprise visibility and …

A Logistic Regression And Markov Chain Model For The Prediction Of Nation-State Violent Conflicts And Transitions, Nicholas Shallcross

Theses and Dissertations

Using open source data, this research formulates and constructs a suite of statistical models that predict future transitions into and out of violent conflict and forecasts the regional and global incidences of violent conflict over a ten-year time horizon. A total of thirty predictor variables are tested and evaluated for inclusion in twelve conditional logistic regression models, which calculate the probability that a nation will transition from its current conflict state, either In Conflict or Not in Conflict, to a new state in the following year. These probabilities are then used to construct a series of nation-specific Markov chain models …

Space Object Self-Tracker On-Board Orbit Determination Analysis, Stacie M. Flamos

Theses and Dissertations

Due to the United States' growing dependence on space based assets and the in- creasing number of resident space objects (RSO), improvement of Space Situational Awareness (SSA) capabilities is more necessary than ever. As a way to aid in this need, the Air Force Institute of Technology (AFIT) is developing the Space Object Self-Tracker (SOS) as a proof-of-concept experimental satellite for RSO precision tracking and collision avoidance system in Low Earth Orbit (LEO). Specifically, SOS will use Global Positioning System (GPS) position estimates for on-board orbit de- termination. Currently, SOS will use the Simplified General Perturbations-4 (SGP4) algorithm as its …

Military Applications Of High-Altitude Satellite Orbits In A Multi-Body Dynamical Environment Using Numerical Methods And Dynamical Systems Theory, Meredith M. Wilmer

Theses and Dissertations

The circular restricted three-body problem (CR3BP) is a simplified dynamical model for a satellite under the gravitational influence of both the Earth and the Moon, maintaining closer fidelity to the gravitational environment experienced by a high-altitude Earth-orbiting spacecraft than modeling in the Earth-satellite two-body problem. Resonant orbit arcs are used to determine an initial guess to input into an algorithm that computes a trajectory solution with specific design requirements and constraints. A test case uses this method to compute a lunar fly-by transfer solution requiring less than two-body transfer methods and offers an unusual pathway that adds an unpredictability element …

Applications Of Correlated 2d-Acar And Cdbar Using A Low-Energy Positron Beam, Angelo M. Bonavita

Theses and Dissertations

The three-dimensional positron annihilation spectroscopy system (3D-PASS) at the Air Force Institute of Technology (AFIT) correlates coincidence Doppler broadening of annihilation radiation with two-dimensional angular correlation of annihilation radiation measurements using two position-sensitive, high-purity germanium (HPGe) detectors. The low photoelectric cross section of germanium, combined with the limited output of the radioisotope-based positron beam, produced sparse data necessitating careful data extraction. Processing techniques employed to increase 3D-PASS spectra quality include an improved algorithm for determining radiation-interaction position on HPGe double-sided strip detectors, a momentum sampling function based correction scheme and spectra folding informed by crystal symmetries. The 3D nature of …

Determining The Degree Of The Routinization Of Additive Manufacturing In The Air Logistics Complexes, Candis A. Woods

Theses and Dissertations

Fiscal constraints have affected the USAF’s spending and sustainment of weapons systems that are being utilized beyond their programmed life cycle; therefore, it is imperative that processes be given the critical eye for improvement, innovative approaches, and/or best practice implementation. The AFSC, part of the AFMC, has embarked on a groundbreaking effort to transform operations and leverage industry best practices, while maintaining focus on warfighter support to create “The AFSC Way.” The AFSC Way is based on a shared leadership model that emphasizes speed, safety, and quality, which gives way to innovative ideas and new technologies in order to achieve …

A Model Of Ambient Noise Caused By Wind Flow, Jovan Popovich

Theses and Dissertations

The generation of noise caused by wind owing past a human ear is an important yet vastly understudied factor in determining the ambient noise of an environment experienced by a human observer. Sound level measurements were obtained from wind tunnel tests simulating a human experiencing wind ows at various speeds and from various directions. This data set was used in this thesis. This thesis presents a collection of models for predicting wind noise levels across a broad spectrum of frequencies based on wind speed and angle inputs. Graphical approaches are included to characterize the observed data and illustrate the models' …

Material And Design Considerations For A Portable Ultra-Violet (Uv) Light Emitting Diode (Led) Water Purification Device, Drew D. Gallucci

Theses and Dissertations

Department of Defense personnel often deploy to austere environments where clean water is not readily available. Ultraviolet (UV) radiation through the use of light emitting diodes (LEDs) in a portable device offers a potential method for expedient water treatment. This research studied the application of one diode, low power, UV LEDs and nine diode, high power, UV LEDs within a portable steel reactor and Teflon reactors of three different wall thicknesses. Reactor efficiency was determined through measuring and comparing the rate constants for Advanced Oxidation of hydrogen peroxide with yellow tartrazine as a witness dye. Experiments conducted with low power …