Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 49381 - 49410 of 196902

Full-Text Articles in Engineering

Using Motion Capture And Augmented Reality To Test Aar With Boom Occlusion, Vincent J. Bownes Mar 2021

Using Motion Capture And Augmented Reality To Test Aar With Boom Occlusion, Vincent J. Bownes

Theses and Dissertations

The operational capability of drones is limited by their inability to perform aerial refueling. This can be overcome by automating the process with a computer vision solution. Previous work has demonstrated the feasibility of automated aerial refueling (AAR) in simulation. To progress this technique to the real world, this thesis conducts experiments using real images of a physical aircraft replica and a motion capture system for truth data. It also compares the error between the real and virtual experiments to validate the fidelity of the simulation. Results indicate that the current technique is effective on real images and that the …

Go to article

Real-Time Aerial Magnetic And Vision-Aided Navigation, Daniel J. Clarke Mar 2021

Real-Time Aerial Magnetic And Vision-Aided Navigation, Daniel J. Clarke

Theses and Dissertations

Aerial magnetic navigation has shown to be a viable alternative navigation method that has the potential for world-wide availability, to include over oceans. Obtaining GPS-level accuracy using magnetic navigation alone is challenging, but magnetic navigation can be combined with other alternative navigation methods that are more posed to obtaining GPS-level accuracy in their current state. This research presents an aerial navigation solution combining magnetic navigation and vision-aided navigation to aid an inertial navigation system (INS). The navigation solution was demonstrated in real-time playback using simulated magnetic field measurements and flight-test captured visual imagery. Additionally, the navigation solution was flight-tested on …

Go to article

Automated Find Fix And Track With A Medium Altitude Long Endurance Remotely Piloted Aircraft, Aubrey L. Olson Mar 2021

Automated Find Fix And Track With A Medium Altitude Long Endurance Remotely Piloted Aircraft, Aubrey L. Olson

Theses and Dissertations

A limitation in RPA ISR operations is loss of target track if the command link is severed. For an RPA to effectively execute the ISR mission without a command link, it needs the capability to F2T targets autonomously. Automated Find Fix and Track (AFFTRAC) was developed to help solve this problem by demonstrating a proof of concept tactical autopilot. Monocular stereo vision was used to process sequential images acquired during orbit to produce a partial structural point cloud of the original structure. This partial structural point cloud was then exploited to create a holding area density for the aircraft to …

Go to article

Investigating Manufacturer Selection Decisions For Built Infrastructure Assets Using A Technical Performance Metric, Sarah L. Brown Mar 2021

Investigating Manufacturer Selection Decisions For Built Infrastructure Assets Using A Technical Performance Metric, Sarah L. Brown

Theses and Dissertations

Facility and built infrastructure asset management are necessary functions of any organization that utilizes buildings to operate their businesses. However, most organizations require facility managers to ensure the successful operation of their assets without providing sufficient resources to accomplish this task. Therefore, in resource-scarce environments, facility managers require data-driven solutions to manage their assets and make the best decisions. Facility managers need novel solutions to help make asset life-cycle decisions. This research provides such a solution. Capitalizing on available data, a technical performance metric is created, allowing facility managers to calculate their assets' operational performance. This performance metric provides a …

Go to article

Accelerating Point Set Registration For Automated Aerial Refueling, Ryan M. Raettig Mar 2021

Accelerating Point Set Registration For Automated Aerial Refueling, Ryan M. Raettig

Theses and Dissertations

The goal of AAR is to control the tanker boom to safely refuel a receiving aircraft with no input or aid from the boom operator. To achieve this, the pose of the receiver relative to the tanker must be known. Point set registration is a fundamental issue used to estimate the relative pose of an object in an environment. However, it's likely a computational bottleneck of a vision processing pipeline. In addition, the matching of each sensed point with a closest truth point, nearest neighbor matching, is the most costly portion of the point set registration process. For this reason, …

Go to article

The Utility Of Modeling An Enterprise Architecture For Air Force Digital Transformation, Mark W. Kassan Mar 2021

The Utility Of Modeling An Enterprise Architecture For Air Force Digital Transformation, Mark W. Kassan

Theses and Dissertations

The Air Force Materiel Command is undergoing a digital transformation to increase the speed of delivering new warfighter capabilities. This Digital Campaign consists of six Lines of Effort (LOEs) formed with diverse goals to transform the enterprise. This research investigated using the Zachman Framework and Systems Modeling Language to analyze this transformation. Extensive modeling captured the as-is Preliminary Design Review (PDR) process, and mapped LOE goals as primary impacts to Zachman cells. This led to an identification of a to-be digital PDR process. Secondary affected cells were then traced following a relationship analysis. Four discoveries were made. (1) Enterprise modeling …

Go to article

Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland Mar 2021

Studying The Conditions For Magnetic Reconnection In Solar Flares With And Without Precursor Flares, Seth H. Garland

Theses and Dissertations

Forecasting of solar flares remains a challenge due to the limited understanding of the triggering mechanisms associated with magnetic reconnection, the primary physical phenomenon connected to these events. Consequently, methods continue to rely on the climatology of solar flare events as opposed to the underlying physics principles. Models of magnetic reconnection in the solar atmosphere places the null point of the reconnection within the corona. Though as of now the coronal magnetic field cannot be directly measured, the field is tied to the photospheric magnetic field, which can be. This study utilized data from the Solar Dynamics Observatory Helioseismic and …

Go to article

Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay Mar 2021

Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay

Theses and Dissertations

Collaborations utilizing small spacecraft in near earth orbit between the U. S. Coast Guard Academy (CGA), Naval Research Lab (NRL), the U. S. Naval Academy (USNA), and the Air Force Institute of Technology (AFIT) have initiated scientific and engineering space-based experiments. Sourced opportunities like the VaSpace ThinSat missions have provided a platform for payload, sensor, and experiment development that would have otherwise been resource prohibitive. We have constructed an impedance probe payload derived from the existing ‘Space PlasmA Diagnostic suitE’ (SPADE) mission operating from NASA’s International Space Station. Currently both space and laboratory plasmas are investigated with AC impedance measurements …

Go to article

Fluid Dynamics Modeling For Per- And Polyfluoroalkyl Substances Removal In Legacy Fire Suppression Systems, Jacob G. Spaulding Mar 2021

Fluid Dynamics Modeling For Per- And Polyfluoroalkyl Substances Removal In Legacy Fire Suppression Systems, Jacob G. Spaulding

Theses and Dissertations

Legacy per- and polyfluoroalkyl substances (PFASs) exist in the form of aqueous film-forming foams within hangar fire suppression systems throughout the country, posing a threat to both surrounding environments as well as local populations. The United States (US) Department of Defense (DoD), in conjunction with the US Environmental Protection Agency (EPA), is investigating best practices to flush out existing contaminants prior to disposal and replacement with a less environmentally harmful replacement. While current procedures dictate a triple rinse of the entire system to yield contaminant levels acceptable to the DoD, the practice has never truly been tested. Designed as a …

Go to article

Space To High-Altitude Region Adjoint Neutron Transport, Zachary W. Lamere Mar 2021

Space To High-Altitude Region Adjoint Neutron Transport, Zachary W. Lamere

Theses and Dissertations

The goal of this work was to use the adjoint transport equation to characterize the energy spectrum of a point neutron source using the time-energy fluence at the satellite. The adjoint transport was solved via Monte Carlo methods in the new program called Space to Air High-Altitude Region Adjoint (SAHARA). A new adjoint source event estimator was developed to improve the computational efficiency. This work explores SAHARA’s performance using mono-energetic and continuous sources. In general, the identified source spectra were noticeably shifted towards lower energies, but were able to capture the source spectrum shapes. Lastly, SAHARA was applied to the …

Go to article

Characterization Of The Spatial Distribution And Evolution Of Cerium And Calcium In Laser Produced Plasma, Michael G. Rynders Mar 2021

Characterization Of The Spatial Distribution And Evolution Of Cerium And Calcium In Laser Produced Plasma, Michael G. Rynders

Theses and Dissertations

Understanding plasma plumes and the distribution of plasma species microseconds after their formation has a variety of applications in fields such as hypersonics, explosion and combustion dynamics, and nuclear fireball chemistry. In this work, Laser Induced Breakdown Spectroscopy (LIBS) using double pulses of 532 nm light were used to analyze samples of cerium in atmospheres of air, vacuum, and argon. Cerium was used in this experiment to serve as a plutonium surrogate. CeO2 powder was pressed with CaO at 90-10 ratio to produce calcium doped pellets for use as sputtering targets. Inclusion of calcium impurities allowed the identification of …

Go to article

Application Of Artificial Neural Networks To Elemental Assay Data For Nuclear Forensics Analysis, Jason G. Seik Mar 2021

Application Of Artificial Neural Networks To Elemental Assay Data For Nuclear Forensics Analysis, Jason G. Seik

Theses and Dissertations

There is a need to quickly and accurately determine the likely physical origins of a collected sample for nuclear treaty verification purposes. The objective of this research is to prove there is a means to relate different samples (Q-values) to one another using a 'same versus not-same' artificial neural network called a Siamese network. This would provide the capability of comparing an unknown sample to a database of samples with known physical origins. Using moment transformations on current data has shown to increase the prediction capabilities of a Siamese network, and using a triplet loss function in connection with the …

Go to article

Lithium Compound Characterization Via Laser Induced Breakdown Spectroscopy And Raman Spectroscopy, James T. Stofel Mar 2021

Lithium Compound Characterization Via Laser Induced Breakdown Spectroscopy And Raman Spectroscopy, James T. Stofel

Theses and Dissertations

Industries such as lithium-ion battery producers and the nuclear industry community seek to produce and store lithium in pure chemical forms. However, these lithium compounds are reactive with the atmosphere and quickly degrade into less desirable forms. Therefore, industry desires a fast and effective quality control approach to quantify the ingrowth of these secondary lithium chemical forms. This research presents a novel approach using Laser-Induced Breakdown Spectroscopy (LIBS) and Raman spectroscopy in tandem to enhance lithium compound characterization beyond what is achieved by either technique alone. The resulting spectral data are aggregated using data fusion and analyzed using chemometrics for …

Go to article

The Obstacles To The Modernization Of Common Support Equipment, J. Erik Ritschard Mar 2021

The Obstacles To The Modernization Of Common Support Equipment, J. Erik Ritschard

Theses and Dissertations

The current fleet of Common Support Equipment (CSE) is faced with a $2B funding disconnect that threatens 9 of the 12 USAF Core Functions. This research identifies the barriers to efforts to modernize CSE across the sustainment, acquisition, and maintenance communities. Using a qualitative, grounded theory methodology, the responses are explored of interviewed Support Equipment managers responsible for the sustainment and modernization of CSE. Significant barriers to current modernization efforts were exposed, resulting in expensive, duplicative, and unreliable equipment; concluding that the AF must change the way CSE is administrated, funded, and culturally understood to prevent future mission degradation.

Go to article

Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson Mar 2021

Defensive Counterair For Air Base Air Defense Using Directed Energy And Kinetic Energy Weapons, Andrew S. Wilson

Theses and Dissertations

Air bases in key locations provide a strategic advantage to the countries that access them, and are at constant threat from adversaries. This research seeks to determine the optimal maneuvering of a fixed number of fighter aircraft in a combat air patrol for defensive counterair to maximally and effectively attrit the inbound cruise missile threat to a stationary high value asset such as an air base. The problem formulation identifies multiple objectives for the model: minimize the distance traveled for the fighters, minimize the time utilized to engage the incoming cruise missiles, and maximize the number of cruise missiles destroyed. …

Go to article

Developing Infrastructure Adaptation Pathways To Combat Hurricane Intensification: A Coupled Storm Simulation And Economic Modeling Framework For Coastal Installations, Alexander J. Baldwin Mar 2021

Developing Infrastructure Adaptation Pathways To Combat Hurricane Intensification: A Coupled Storm Simulation And Economic Modeling Framework For Coastal Installations, Alexander J. Baldwin

Theses and Dissertations

Climate change projections suggest intensification of extreme weather events, including hurricanes, is expected throughout the 21st century. This will lead to increased destruction for coastal military bases unless infrastructure resiliency and adaptation measures are implemented. This research focuses on examining the simulation of probabilistic, climate-intensified hurricane events at Eglin Air Force Base. FEMA Hazus models are combined with climate projections for wind Intensity, tide, and sea-level rise to produce an assessment of losses to the installation. Damage estimates and hurricane intensity outputs are downscaled to the facility-level so that climate adaptation signals can be identified. The facility losses and climate …

Go to article

Display Design To Avoid And Mitigate Limit Cycle Oscillations (Lco) On The F-16c, David J. Feibus Mar 2021

Display Design To Avoid And Mitigate Limit Cycle Oscillations (Lco) On The F-16c, David J. Feibus

Theses and Dissertations

The U.S. Air Force F-16 Fighting Falcons flying characteristics and flight envelope are dynamic and defined by its external weapon stores configuration. The employment of its munitions at certain speeds can put the F-16 into a flutter-like state in which Limit Cycle Oscillations (LCO) are induced. In LCO, a pilots fine motor control might be hindered, and the aircraft may lose combat effectiveness until flight conditions are reduced. The current research attempted to provide pilots with a predictive feedback display to avoid an LCO-susceptible configuration by increasing their situation awareness about the consequences of employing certain munitions to their flight …

Go to article

Long Distance Bluetooth Low Energy Exploitation On A Wireless Attack Platform, Stephanie L. Long Mar 2021

Long Distance Bluetooth Low Energy Exploitation On A Wireless Attack Platform, Stephanie L. Long

Theses and Dissertations

In the past decade, embedded technology, known as the Internet of Things, has expanded for many uses. The smart home infrastructure has drastically grown to include networked refrigerators, lighting systems, speakers, watches, and more. This increase in the use of wireless protocols provides a larger attack surface for cyber actors than ever before. Wireless loT traffic is susceptible for sniffing by an attacker. The attack platform skypie is upgraded to incorporate Bluetooth Low Energy (BLE) beacon collection for pattern-of-life data, as well as device characteristic enumeration and potential characteristic modification. This platform allows an attacker to mount the skypie to …

Go to article

Guidance For Building Motivation In Space Operator Training, Foster E. Davis Mar 2021

Guidance For Building Motivation In Space Operator Training, Foster E. Davis

Theses and Dissertations

Services provided by spacecraft, including communications and global positioning, are integral to small businesses, multinational corporations, and the United States Department of Defense. United States rivals recognize the need to undermine the military advantage provided by the space domain and are exploring ways to degrade these services in their warfare doctrine. In response, the United States will need space systems suited to counter these threats and personnel who are trained to respond to the new reality of a contested space environment. This paper also reviews the academic literature and written guidelines for developing motivation in an interactive environment for improving …

Go to article

Modeling Situation Awareness In A Uav Scenario Using Sysml, Tommy R. Hernandez Mar 2021

Modeling Situation Awareness In A Uav Scenario Using Sysml, Tommy R. Hernandez

Theses and Dissertations

The U.S. Department of Defense (DoD) is rapidly moving towards using increasingly automated systems. Unmanned Aerial Systems (UAS) will be used in contested environments where direct human control may be impossible for long stretches of time. This increase in automation brings with it challenges in maintaining resilient Situation Awareness (SA) for operators, who still need to set goals for the UAS to accomplish their missions. Simultaneously, the DoD is increasing the adoption of Model-Based Systems Engineering (MBSE) in the development of weapon systems. This thesis explores the use of SysML to model of an SA repair system for a UAS …

Go to article

The Wargaming Commodity Course Of Action Automated Analysis Method, William T. Deberry Mar 2021

The Wargaming Commodity Course Of Action Automated Analysis Method, William T. Deberry

Theses and Dissertations

This research presents the Wargaming Commodity Course of Action Automated Analysis Method (WCCAAM), a novel approach to assist wargame commanders in developing and analyzing courses of action (COAs) through semi-automation of the Military Decision Making Process (MDMP). MDMP is a seven-step iterative method that commanders and mission partners follow to build an operational course of action to achieve strategic objectives. MDMP requires time, resources, and coordination – all competing items the commander weighs to make the optimal decision. WCCAAM receives the MDMP's Mission Analysis phase as input, converts the wargame into a directed graph, processes a multi-commodity flow algorithm on …

Go to article

Robust Scandium Aluminum Nitride Mems Resonators For L Band Operation In Orbital Environments, Israel W. Dunk Mar 2021

Robust Scandium Aluminum Nitride Mems Resonators For L Band Operation In Orbital Environments, Israel W. Dunk

Theses and Dissertations

This thesis investigates AlN alloyed with scandium in a variety of resonator architectures including WEM, overtone WEM, LEM, and SAW that have the potential to achieve high levels of electrical performance and environmental robustness. SAW resonators operating near 370 MHz are fabricated on polycrystalline Sc.37Al.63N, and AlN with the resulting devices compared and conclusions drawn as to the merits of each material. The design and fabrication of SAW devices is discussed in detail, with the operating characteristics of these resonators then tested both electrically and mechanically. Mechanical characterisation includes analysis of vibration and shock effects on …

Go to article

Surface Defect Detection In Aircraft Skin & Visual Navigation Based On Forced Feature Selection Through Segmentation, Tyler B. Hussey Mar 2021

Surface Defect Detection In Aircraft Skin & Visual Navigation Based On Forced Feature Selection Through Segmentation, Tyler B. Hussey

Theses and Dissertations

Visual inspection of aircraft skin for surface defects is an area of maintenance that is particularly intensive for time and manpower. One novel way to combat this problem is through the use of computer vision and the advent of Artificial Neural Networks (ANN), or more specifically, semantic segmentation via Convolutional Neural Networks (CNN). The research in the paper explores the use of semantic segmentation of aerial imagery as a way to force feature selection onto key areas of an image that might be more likely to correspond under seasonal variations. Utilizing feature selection and matching on the masked aerial image …

Go to article

Examining Military Cargo Pilots' Eco-Friendly Flying Intention, Ioan A. Gaitan Mar 2021

Examining Military Cargo Pilots' Eco-Friendly Flying Intention, Ioan A. Gaitan

Theses and Dissertations

The US Air Force is the largest operational energy consumer within the Department of Defense primarily due to aviation fuel use. Military pilots can play important roles in saving aviation fuel by flying aircraft in an eco-friendly manner. According to the theory of planned behavior (TPB), intention is the major predictor of behavior. This study tests two models based on TPB for understanding cargo pilots’ eco-friendly intentions when they conduct channel or logistics missions. The study found that attitude, subjective norm, and perceived behavior control were significant antecedents to intention in a multiple regression with aggregated scales.

Go to article

Examining The Impact Of Logistics On Military Strength Among European Nations Using Data Envelopment Analysis, Hunter C. Kalin Mar 2021

Examining The Impact Of Logistics On Military Strength Among European Nations Using Data Envelopment Analysis, Hunter C. Kalin

Theses and Dissertations

The purpose of this study is to evaluate if logistics and economic factors affect how a country achieves its military power. Countries have focused on material factors such as nuclear weapons or massive military presence for far too long. What has not been discussed is, do other factors play a role in achieving military power. This study applied Data Envelopment Analysis (DEA) and linear regression to a series of United States European Command (EUCOM) countries and the United States to understand how efficient each country was at achieving its military power. Additionally, the overall relationship between military power and each …

Go to article

Improving Airfield Pavement Degradation Prediction Skill With Local Climate And Traffic, Evan M. Fortney Mar 2021

Improving Airfield Pavement Degradation Prediction Skill With Local Climate And Traffic, Evan M. Fortney

Theses and Dissertations

Airfield pavements are a critical component of the global transportation network that provide a platform for national defense. Preventative and corrective maintenance activities are founded upon accurate expectations of degradation. The leading pavement management software creates degradation predictions from pavement groups using age as the IV and current state conditions as the DV. For this work, a framework is created and implemented that utilizes a PCR model to build upon accepted practices for degradation modeling to enhance and possibly augment future prediction capabilities. The model was applied to pairs of location and pavement family and reveals several findings: the selected …

Go to article

Mitigating The Multipath Effects On Radio Tomographic Imaging, Destinee N. Battle Mar 2021

Mitigating The Multipath Effects On Radio Tomographic Imaging, Destinee N. Battle

Theses and Dissertations

Various radio tomographic imaging (RTI) models and reconstruction methods are equipped with capabilities to mitigate the effects of multipath interference. This thesis combined the network shadowing (NeSh) and weighting-g models in conjunction with Tikhonov regularization and low-rank and sparse decomposition (LRSD). MATLAB was used to implement the four combinations for six experimental data sets and produce attenuation images. The attenuation images were analyzed qualitatively and quantitatively to accomplish the goal of determining which combination performed best at locating human targets. After analyzing the results, it was determined that no single combination outperformed the others for at least three out of …

Go to article

Indoor Navigation Using Convolutional Neural Networks And Floor Plans, Ricky D. Anderson Mar 2021

Indoor Navigation Using Convolutional Neural Networks And Floor Plans, Ricky D. Anderson

Theses and Dissertations

The goal of this thesis is to evaluate a new indoor navigation technique by incorporating floor plans along with monocular camera images into a CNN as a potential means for identifying camera position. Building floor plans are widely available and provide potential information for localizing within the building. This work sets out to determine if a CNN can learn the architectural features of a floor plan and use that information to determine a location. In this work, a simulated indoor data set is created and used to train two CNNs. A classification CNN, which breaks up the floor plan into …

Go to article

Comparison Of Conic Ray Tracing For Occlusion Determination On 3d Point Cloud Data, Henry Cho Mar 2021

Comparison Of Conic Ray Tracing For Occlusion Determination On 3d Point Cloud Data, Henry Cho

Theses and Dissertations

The US Air Force has been increasing the use of automation in its weapon systems to include the remotely piloted aircraft (RPA) platforms. The RPA career field has had issues with poor pilot retention due to job stressors. For example, RPA operators spend a lot of time and attention surveilling a suspect on the ground for many hours, so adding automation to this activity could help improve pilot retention. The research problem in this thesis attempted to automate the process of observing a ground target. This thesis presents a method termed conic ray tracing for determining visibility and occlusion of …

Go to article

Modeling Aircraft Disturbance Fields For Magnetic Navigation Using Dense Anns And The Novel Manntl Architecture, Kyle A. Emery Mar 2021

Modeling Aircraft Disturbance Fields For Magnetic Navigation Using Dense Anns And The Novel Manntl Architecture, Kyle A. Emery

Theses and Dissertations

The ability to use GPS for navigation is becoming increasingly limited in certain areas of the world. Knowing this, the Air Force Research Labs is constantly looking for ways to improve alternate navigation methods such as magnetic navigation. In the interest of making advancements in aircraft disturbance field modelling, Lieutenant Emery recreates models from previous works to prove results. Lieutenant Emery also introduces a novel model architecture that attempts to mix the filtering properties of Tolles-Lawson with the non-linear capabilities of an artificial neural network. The introduction of this model could present better aircraft disturbance field modelling and in turn, …

Go to article

First Prev Next Last