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Articles 1141 - 1170 of 5699
Full-Text Articles in Engineering
Human Performance Modeling: Analysis Of The Effects Of Manned-Unmanned Teaming On Pilot Workload And Mission Performance, Jinan M. Andrews
Human Performance Modeling: Analysis Of The Effects Of Manned-Unmanned Teaming On Pilot Workload And Mission Performance, Jinan M. Andrews
Theses and Dissertations
Due to the advent of autonomous technology coupled with the extreme expense of manned aircraft, the Department of Defense (DoD) has increased interest in developing affordable, expendable Unmanned Aerial Vehicles (UAVs) to become autonomous wingmen for jet fighters in mosaic warfare. Like a mosaic that forms a whole picture out of smaller pieces, battlefield commanders can utilize disaggregated capabilities, such as Manned-Unmanned Teaming (MUM-T), to operate in contested environments. With a single pilot controlling both the UAVs and manned aircraft, it may be challenging for pilots to manage all systems should the system design not be conducive to a steady …
Preliminary Study Of Communication Network Characterization Towards Improved Organizational Behavior, Taylor F. Flaxington
Preliminary Study Of Communication Network Characterization Towards Improved Organizational Behavior, Taylor F. Flaxington
Theses and Dissertations
Nearly one third of the Air Force acquisition system’s large programs are over cost and half are over budget; performance must improve. This research applies a systems perspective to this challenge and frames the acquisition system as a complex system of systems. It is a system composed of people in multiple organizations; organizations interacting with one another to develop, acquire and sustain weapon programs. The system’s performance is an emergent behavior of its components (people), structure and processes. Communication networks are a view of a system’s structure, revealing the flows and interactions between components (people) as the system accomplishes its …
A Comparison Of Sbir Investment Methods: Afwerx Vs Legacy, Evan A. Gist
A Comparison Of Sbir Investment Methods: Afwerx Vs Legacy, Evan A. Gist
Theses and Dissertations
The AFWERX Open Topic (AOT) program uses funding from the United States Air Force’s (USAF) Small Business Innovation and Research (SBIR) budget to adapt commercial technology to USAF needs. The AOT approach to small business investment is markedly different from that of legacy SBIR investment methods. This research is a comparison of processes and outcomes for AOT and legacy SBIR. The first axis of comparison is on commercialization rates. Applying a legacy definition of commercialization on a sample of AOT contracts, we found AOT’s commercialization to be 37% (compared to an 8.8% for legacy SBIR). We caveat this finding by …
Analyzing Cost Effectiveness Of Photovoltaic Pavements, Ian N. Parks
Analyzing Cost Effectiveness Of Photovoltaic Pavements, Ian N. Parks
Theses and Dissertations
The United States Air Force (USAF) is the largest consumer of energy within the Department of Defense (DoD). As such, the USAF is continually looking for ways to reduce consumption, as well improving network resiliency and assuring supply. One potential method for addressing these items is focusing on applications of renewable energy. A specific application of renewable energy that could greatly benefit the USAF if viable would be photovoltaic (PV) pavements. PV pavements would be able to capitalize upon the large swathes of pavements on Air Force (AF) installations, while not being hampered by other concerns such as clear zones …
Analysis Of Construction Management At Risk Projects For Unites States Air Force Applicability, Danielle K. Tabb
Analysis Of Construction Management At Risk Projects For Unites States Air Force Applicability, Danielle K. Tabb
Theses and Dissertations
Construction management at risk is a project delivery method that sees widespread use in the private and public non-federal construction sectors. There is interest in the federal government of using a project delivery method such as construction management at risk. However, guiding regulations prohibit the federal government from using it as it is utilized in the private sector. This research analyzes private sector use of construction management at risk through a literature review and Delphi Panel, in order to determine its effects on project performance. The Delphi Panel consisted of two rounds of questions; the experts were selected through a …
Optimization Of Airfield Parking And Fuel Asset Dispersal To Maximize Survivability And Mission Capability Level, Ryley R. H. Paquette
Optimization Of Airfield Parking And Fuel Asset Dispersal To Maximize Survivability And Mission Capability Level, Ryley R. H. Paquette
Theses and Dissertations
While the US focus for the majority of the past two decades has been on combatting insurgency and promoting stability in Southwest Asia, strategic focus is beginning to shift toward concerns of conflict with a near-peer state. Such conflict brings with it the risk of ballistic missile attack on air bases. With 26 conflicts worldwide in the past 100 years including attacks on air bases, new doctrine and modeling capacity are needed to enable the Department of Defense to continue use of vulnerable bases during conflict involving ballistic missiles. Several models have been developed to date for Air Force strategic …
Determination And Simulation Of The Neutron Spectrum Of Nuclear Detonations And Surrogate Sources, Taylor M. Nichols
Determination And Simulation Of The Neutron Spectrum Of Nuclear Detonations And Surrogate Sources, Taylor M. Nichols
Theses and Dissertations
This research determined a methodology for characterizing the Fast Beam Facility (FBF) at The Ohio State University Nuclear Reactor Laboratory to test the response of photovoltaic arrays to nuclear weapon radiation. Additionally, this research developed neutron and gamma nuclear weapon output spectra of two environments for comparison to the FBF spectrum. A Bonner sphere spectrometer (BSS), coupled with the unfolding program Maximum Entropy Deconvolution (MAXED), was employed as a means of determining the energy spectrum of neutrons. Using the ISO 8529 americium beryllium (AmBe) source as the a priori default spectrum, MAXED was used to unfold the spectrum of neutrons …
Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal
Analysis Of The Correlation Between Re Filament Surface Features And Tims Performance, Christopher J. Mihal
Theses and Dissertations
Thermal Ionization Mass Spectrometry (TIMS) is an invaluable tool in nuclear forensics as it enables isotopic assays of actinides to be measured, permitting analysis to include special nuclear material isotopic assays, nuclear reactor monitoring, and treaty verification. In one method of measurement for the TIMS system, samples are deposited in solution form on high-purity rhenium filaments. The filaments are heated to evaporate the solvent, and then further heated to cause sample ionization, permitting the sample to be transmitted through a magnetic field which separates ions based on mass to charge ratio into detectors for counting. Heavier ions will be deflected …
Determination Of Lithium Isotope Concentration By Laser Induced Breakdown Spectroscopy Using Chemometrics, Jason C. Wood
Determination Of Lithium Isotope Concentration By Laser Induced Breakdown Spectroscopy Using Chemometrics, Jason C. Wood
Theses and Dissertations
The role of enriched 6Li in nuclear applications makes the ability to detect and monitor lithium enrichment activity imperative. Detecting levels of enrichment of this isotope currently requires sensitive, complex equipment operated by highly-trained technicians, which is prohibitive to rapid detection of enrichment activity. While commercial companies market portable laser induced breakdown spectroscopy (LIBS) with the ability to detect elements on the order or parts per million concentrations, they have not yet been demonstrated to possess the ability to quantitatively determine isotopic concentrations of lithium. This research performs single-pulse LIBS experiments under laboratory conditions to determine concentrations of 7Li and …
Examining Healthy Community Design Characteristics And Its Influence On Physical Health, Alvin T. Yip
Examining Healthy Community Design Characteristics And Its Influence On Physical Health, Alvin T. Yip
Theses and Dissertations
Current trends in obesity rates associated with the community layout constitutes research towards understanding the interaction between the two in order to improve the public's physical health. Successes in healthy community planning studies for the public can be harnessed and implemented within the microcosm of military bases to yield similar results. Four factors were recognized through an in-depth academic literature review that showed positive influence on physical health and physical activity. They are access to green space, highly connected pedestrian and bicycle networks, access to public transportation, and integrated mixed land use. The four healthy planning strategies formed the necessary …
Detection Of Reconnection Signatures In Solar Flares, Taylor R. Whitney
Detection Of Reconnection Signatures In Solar Flares, Taylor R. Whitney
Theses and Dissertations
Solar flare forecasting is limited by the current understanding of mechanisms that govern magnetic reconnection, the main physical phenomenon associated with these events. As a result, forecasting relies mainly on climatological correlations to historical events rather than the underlying physics principles. Solar physics models place the neutral point of the reconnection event in the solar corona. Correspondingly, studies of photospheric magnetic fields indicate changes during solar flares -- particularly in relation to the field helicity -- on the solar surface as a result of the associated magnetic reconnection. This study utilizes data from the Solar Dynamics Observatory (SDO) Helioseismic and …
Simulation Of Sporadic-E Parameters Using Phase Screen Method, Daniel W. Stambovsky
Simulation Of Sporadic-E Parameters Using Phase Screen Method, Daniel W. Stambovsky
Theses and Dissertations
A phase screen simulation experiment is designed and implemented to model radio occultation through sporadic-E ionospheric disturbances between a GPS transmitter operating at the L1 frequency and a second receiving satellite in low earth orbit (LEO). Simulations were made to test the linear relationship between plasma intensity and scintillation S4 index both posited (Arras and Wickert, 2018) and contended (Gooch et al., 2020) in previous literature. Results brought into question both the linear relationship and the use of S4 as a whole and an alternate metric was sought.
Conduction Mapping For Quality Control Of Laser Powder Bed Fusion Additive Manufacturing, Chance M. Baxter
Conduction Mapping For Quality Control Of Laser Powder Bed Fusion Additive Manufacturing, Chance M. Baxter
Theses and Dissertations
A process was developed to identify potential defects in previous layers of Selective Laser Melting (SLM) Powder Bed Fusion (PBF) 3D printed metal parts using a mid-IR thermal camera to track infrared 3.8-4 m band emission over time as the part cooled to ambient temperature. Efforts focused on identifying anomalies in thermal conduction. To simplify the approach and reduce the need for significant computation, no attempts were made to calibrate measured intensity, extract surface temperature, apply machine learning, or compare measured cool-down behavior to computer model predictions. Raw intensity cool-down curves were fit to a simplified functional form designed to …
Interoperable Ads-B Confidentiality, Brandon C. Burfeind
Interoperable Ads-B Confidentiality, Brandon C. Burfeind
Theses and Dissertations
The worldwide air traffic infrastructure is in the late stages of transition from legacy transponder systems to Automatic Dependent Surveillance - Broadcast (ADS-B) based systems. ADS-B relies on position information from GNSS and requires aircraft to transmit their identification, state, and position. ADS-B promises the availability of high-fidelity air traffic information; however, position and identification data are not secured via authentication or encryption. This lack of security for ADS-B allows non-participants to observe and collect data on both government and private flight activity. This is a proposal for a lightweight, interoperable ADS-B confidentiality protocol which uses existing format preserving encryption …
Pedestrian Navigation Using Artificial Neural Networks And Classical Filtering Techniques, David J. Ellis
Pedestrian Navigation Using Artificial Neural Networks And Classical Filtering Techniques, David J. Ellis
Theses and Dissertations
The objective of this thesis is to explore the improvements achieved through using classical filtering methods with Artificial Neural Network (ANN) for pedestrian navigation techniques. ANN have been improving dramatically in their ability to approximate various functions. These neural network solutions have been able to surpass many classical navigation techniques. However, research using ANN to solve problems appears to be solely focused on the ability of neural networks alone. The combination of ANN with classical filtering methods has the potential to bring beneficial aspects of both techniques to increase accuracy in many different applications. Pedestrian navigation is used as a …
Effects Of Long-Term Evolution Waveform On Synthetic Aperture Radar Image Quality Metrics, Blake M. Colson
Effects Of Long-Term Evolution Waveform On Synthetic Aperture Radar Image Quality Metrics, Blake M. Colson
Theses and Dissertations
As a greater demand by the private sector for bandwidth drives spectrum allocations away from defense, new methods for coexistence in the spectrum are being explored. One of the prominent areas in defense for this coexistence is passive radar. This mode of radar system allows for data collection by referencing signals already established in the environment of interest. Some of the most prolific signals currently available are those used for mobile communication networks. In particular, Long- Term Evolution (LTE) is a common waveform that could be leveraged for discrete collection of image intelligence. Seeking to build a base of knowledge, …
Structural Dynamic And Inherent Damping Characterization Of Additively Manufactured Airfoil Components, Andrew W. Goldin
Structural Dynamic And Inherent Damping Characterization Of Additively Manufactured Airfoil Components, Andrew W. Goldin
Theses and Dissertations
The push for low cost and higher performance/efficient turbine engines have introduced a new demand for novel technologies to improve robustness to vibrations resulting in High Cycle Fatigue (HCF). There have been many proposed solutions to this, some passive and some active. With the advent of Additive Manufacturing (AM), new damping techniques can now be incorporated directly into the design and manufacture process to suppress the vibrations that create HCF. In this study, this novel unfused pocket damping technology is applied to a blade structure and the resulting damping effectiveness is quantified. The application of this technology to complex geometries …
Meta Learning Recommendation System For Classification, Clarence O. Williams Iii
Meta Learning Recommendation System For Classification, Clarence O. Williams Iii
Theses and Dissertations
A data driven approach is an emerging paradigm for the handling of analytic problems. In this paradigm the mantra is to let the data speak freely. However, when using machine learning algorithms, the data does not naturally reveal the best or even a good approach for algorithm choice. One method to let the algorithm reveal itself is through the use of Meta Learning, which uses the features of a dataset to determine a useful model to represent the entire dataset. This research proposes an improvement on the meta-model recommendation system by adding classification problems to the candidate problem space with …
Neutron Energy Effects On Asteroid Deflection, Lansing S. Horan Iv
Neutron Energy Effects On Asteroid Deflection, Lansing S. Horan Iv
Theses and Dissertations
In the future, a hazardous asteroid will find itself on a collision course with Earth. It is an inevitability; the question is not if, but when. For asteroids of moderate size or larger, a nuclear device is one of humanity's only technologies capable of mitigating this threat via deflection on a timescale of less than a decade. This work examined how changing the output neutron energy from a nuclear device detonation affects asteroid deflection. The notional asteroid target was 300 meters in diameter and composed of silicon dioxide at a bulk density of 1.855 g/cm3. To calculate the …
Optimizing The Environmental And Economic Sustainability Of Remote Community Infrastructure, Jamie E. Filer, Justin D. Delorit, Andrew J. Hoisington, Steven J. Schuldt
Optimizing The Environmental And Economic Sustainability Of Remote Community Infrastructure, Jamie E. Filer, Justin D. Delorit, Andrew J. Hoisington, Steven J. Schuldt
Faculty Publications
Remote communities such as rural villages, post-disaster housing camps, and military forward operating bases are often located in remote and hostile areas with limited or no access to established infrastructure grids. Operating these communities with conventional assets requires constant resupply, which yields a significant logistical burden, creates negative environmental impacts, and increases costs. For example, a 2000-member isolated village in northern Canada relying on diesel generators required 8.6 million USD of fuel per year and emitted 8500 tons of carbon dioxide. Remote community planners can mitigate these negative impacts by selecting sustainable technologies that minimize resource consumption and emissions. However, …
Nuclear Data Covariance Analysis In Radiation-Transport Simulations Utilizing Scale Sampler And The Irdff Nuclear Data Library, Nicholas J. Quartemont, Abigail A. Bickley, James E. Bevins
Nuclear Data Covariance Analysis In Radiation-Transport Simulations Utilizing Scale Sampler And The Irdff Nuclear Data Library, Nicholas J. Quartemont, Abigail A. Bickley, James E. Bevins
Faculty Publications
This article describes the nuclear data covariance analysis of an experimental design for a neutron energy-tuning assembly (ETA) created to shape a 14-MeV neutron point source to an objective spectrum. Underlying nuclear data uncertainties play a large role in the radiation transport and reaction rates for the range of responses to be expected from an experiment. The methodology leveraged the Standardized Computer Analysis for Licensing Evaluation (SCALE) Sampler module to determine the uncertainty in the neutron transport. The reaction uncertainty was perturbed with the International Reactor Dosimetry and Fusion File v.1.05 uncertainty, correlation matrix, and reaction cross section through multivariate …
Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments At The National Ignition Facility, Nicholas J. Quartemont, James E. Bevins, Rachel N. Slaybaugh, Lee A. Bernstein
Analysis Of An Energy Tuning Assembly For Simulating Nuclear Weapon Environments At The National Ignition Facility, Nicholas J. Quartemont, James E. Bevins, Rachel N. Slaybaugh, Lee A. Bernstein
Faculty Publications
An energy tuning assembly ETA was developed to spectrally shape the National Ignition Facility NIF deuterium-tritium D-T fusion neutron source to a notional thermonuclear and prompt fission neutron spectrum TNPFNS to approximate a boosted nuclear device. The spectrally shaped neutron environment can be used to create realistic synthetic post-detonation weapon debris that contain spectrally accurate fission products across all mass chains to enhance U.S. technical nuclear forensics capabilities for nuclear weapon attribution and device reconstruction. This research performed nuclear data covariance analysis through stochastic sampling techniques to predict the performance of an ETA to create the objective TNPFNS, assess anticipated …
Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv
Synthesizing General Electromagnetic Partially Coherent Sources From Random, Correlated Complex Screens, Milo W. Hyde Iv
Faculty Publications
We present a method to generate any genuine electromagnetic partially coherent source (PCS) from correlated, stochastic complex screens. The method described here can be directly implemented on existing spatial-light-modulator-based vector beam generators and can be used in any application which utilizes electromagnetic PCSs. Our method is based on the genuine cross-spectral density matrix criterion. Applying that criterion, we show that stochastic vector field realizations (corresponding to a desired electromagnetic PCS) can be generated by passing correlated Gaussian random numbers through “filters” with space-variant transfer functions. We include step-by-step instructions on how to generate the electromagnetic PCS field realizations. As an …
Applications Of Unmanned Aerial Systems (Uas): A Delphi Study Projecting Future Uas Missions And Relevant Challenges, Alberto Sigala, Brent T. Langhals
Applications Of Unmanned Aerial Systems (Uas): A Delphi Study Projecting Future Uas Missions And Relevant Challenges, Alberto Sigala, Brent T. Langhals
Faculty Publications
Over recent decades, the world has experienced a growing demand for and reliance upon unmanned aerial systems (UAS) to perform a broad spectrum of applications to include military operations such as surveillance/reconnaissance and strike/attack. As UAS technology matures and capabilities expand, especially with respect to increased autonomy, acquisition professionals and operational decision makers must determine how best to incorporate advanced capabilities into existing and emerging mission areas. This research seeks to predict which autonomous UAS capabilities are most likely to emerge over the next 20 years as well as the key challenges for implementation for each capability. Employing the Delphi …
Cyber-Physical Security With Rf Fingerprint Classification Through Distance Measure Extensions Of Generalized Relevance Learning Vector Quantization, Trevor J. Bihl, Todd J. Paciencia, Kenneth W. Bauer Jr., Michael A. Temple
Cyber-Physical Security With Rf Fingerprint Classification Through Distance Measure Extensions Of Generalized Relevance Learning Vector Quantization, Trevor J. Bihl, Todd J. Paciencia, Kenneth W. Bauer Jr., Michael A. Temple
Faculty Publications
Radio frequency (RF) fingerprinting extracts fingerprint features from RF signals to protect against masquerade attacks by enabling reliable authentication of communication devices at the “serial number” level. Facilitating the reliable authentication of communication devices are machine learning (ML) algorithms which find meaningful statistical differences between measured data. The Generalized Relevance Learning Vector Quantization-Improved (GRLVQI) classifier is one ML algorithm which has shown efficacy for RF fingerprinting device discrimination. GRLVQI extends the Learning Vector Quantization (LVQ) family of “winner take all” classifiers that develop prototype vectors (PVs) which represent data. In LVQ algorithms, distances are computed between exemplars and PVs, and …
Integrated Quantum Information Processing Controlled Phase Gate, Richard S. Kim, Attila A. Szep, Michael L. Fanto, Paul M. Alsing, Gordon E. Lott, Christopher C. Tison
Integrated Quantum Information Processing Controlled Phase Gate, Richard S. Kim, Attila A. Szep, Michael L. Fanto, Paul M. Alsing, Gordon E. Lott, Christopher C. Tison
AFIT Patents
An electro-optical directional coupler is provided having a substrate and a first and second optical waveguide formed on the substrate, where the second waveguide extends adjacent to and parallel with the first waveguide for at least one interaction length. The interaction length has a first end and a second end such that an optical signal applied only to one of the first and second waveguides couples to the other of the first and second waveguides between the ends. A first electrode is proximate the first and second waveguides and between the ends of the interaction length. A first voltage applied …
A Sequential Partial Information Bomber‐Defender Shooting Problem, Krishna Kalyanam, David W. Casbeer, Meir Pachter
A Sequential Partial Information Bomber‐Defender Shooting Problem, Krishna Kalyanam, David W. Casbeer, Meir Pachter
Faculty Publications
No abstract provided.
Generating Electromagnetic Dark And Antidark Partially Coherent Sources, Milo W. Hyde Iv
Generating Electromagnetic Dark And Antidark Partially Coherent Sources, Milo W. Hyde Iv
Faculty Publications
We present two methods to generate an electromagnetic dark and antidark partially coherent source. The first generalizes a recently published scalar approach by representing the stochastic electric field vector components as sums of randomly weighted, randomly tilted plane waves. The second method expands the field’s vector components in series of randomly weighted dark and antidark coherent modes. The statistical moments of the random weights—plane waves in the former method, coherent modes in the latter—are found by comparing the resulting means and covariances to those of the desired electromagnetic dark and antidark source. We validate both methods by simulating the generation …
Differential Vector Phase Locked Loop Gps Reception Method, James Brewer, John F. Raquet
Differential Vector Phase Locked Loop Gps Reception Method, James Brewer, John F. Raquet
AFIT Patents
A method for enhancing GPS location accuracy includes providing a base station receiver having a known surveyed location, and a roving receiver at a location distinct from the base station receiver. The method further includes receiving single-frequency code and carrier-phase measurements from the base station, and translating the single-frequency code and carrier-phase measurements to a Kalman filter-predicted location of the roving receiver. The translated single frequency code and carrier phase measurements are used to generate a local replica of the Kalman filter-predicted location signals for each channel of the roving receiver. The method further includes correlating the local replicas with …
Graduate School Of Engineering And Management Catalog 2020-2021, Graduate School Of Engineering And Management, Air Force Institute Of Technology
Graduate School Of Engineering And Management Catalog 2020-2021, Graduate School Of Engineering And Management, Air Force Institute Of Technology
AFIT Documents
The Graduate Catalog represents the offerings, programs, and requirements in effect at the time of publication.