Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (5738)
- Physical Sciences and Mathematics (2950)
- Aerospace Engineering (1677)
- Electrical and Computer Engineering (1344)
- Operations Research, Systems Engineering and Industrial Engineering (1247)
-
- Computer Sciences (1236)
- Business (994)
- Physics (919)
- Operational Research (610)
- Signal Processing (459)
- Civil and Environmental Engineering (422)
- Computer Engineering (414)
- Aviation (353)
- Electrical and Electronics (351)
- Social and Behavioral Sciences (349)
- Operations and Supply Chain Management (346)
- Materials Science and Engineering (335)
- Optics (330)
- Oceanography and Atmospheric Sciences and Meteorology (279)
- Navigation, Guidance, Control and Dynamics (252)
- Other Operations Research, Systems Engineering and Industrial Engineering (233)
- Human Resources Management (232)
- Systems Engineering (229)
- Atomic, Molecular and Optical Physics (198)
- Electromagnetics and Photonics (195)
- Aerodynamics and Fluid Mechanics (188)
- Environmental Sciences (188)
- Environmental Engineering (185)
- Nuclear Engineering (180)
- Applied Mathematics (178)
- Keyword
-
- #antcenter (380)
- #csra (135)
- Machine learning (94)
- Decision making (89)
- Algorithms (75)
-
- Global Positioning System (75)
- Image processing (73)
- Kalman filtering (65)
- Optimization (64)
- #afcec (62)
- Computer networks--Security measures (62)
- Drone aircraft (59)
- Computer security (57)
- Target acquisition (57)
- Neural networks (Computer science) (54)
- Software engineering (54)
- Additive manufacturing (52)
- Remote sensing (49)
- Flight control (48)
- Microelectromechanical systems (45)
- Computer vision (44)
- Artificial satellites (43)
- Decision support systems (43)
- #ctisr (42)
- Adaptive optics (42)
- Composite materials (42)
- Neural networks (41)
- Simulation (41)
- Wireless communication systems (41)
- Scheduling (40)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 1471 - 1500 of 8793
Full-Text Articles in Entire DC Network
Implications And Limitations Of Securing An Infiniband Network, Lucas E. Mireles
Implications And Limitations Of Securing An Infiniband Network, Lucas E. Mireles
Theses and Dissertations
The InfiniBand Architecture is one of the leading network interconnects used in high performance computing, delivering very high bandwidth and low latency. As the popularity of InfiniBand increases, the possibility for new InfiniBand applications arise outside the domain of high performance computing, thereby creating the opportunity for new security risks. In this work, new security questions are considered and addressed. The study demonstrates that many common traffic analyzing tools cannot monitor or capture InfiniBand traffic transmitted between two hosts. Due to the kernel bypass nature of InfiniBand, many host-based network security systems cannot be executed on InfiniBand applications. Those that …
Mismatched Filter Effects On Synthetic Aperture Radar Image Quality Metrics, Jerrod M. Kempf
Mismatched Filter Effects On Synthetic Aperture Radar Image Quality Metrics, Jerrod M. Kempf
Theses and Dissertations
Detection of targets across a wide dynamic range is an enduring challenge in radar. This work formulates a modified least-squares mismatched filter that greatly reduces these sidelobes in order to enable the detection of small radar cross section targets in the presence of considerably larger scatterers, increasing the dynamic range. Unlike previous mismatched filters, the proposed filter is applicable to noisy, oversampled signals with no requirements on signal structure. Range profiles and images are presented to demonstrate the superior sidelobe suppression of the modified least-squares mismatched filter in comparison to the commonly employed matched filter. Various weighting vectors are introduced …
Event-Based Visual-Inertial Odometry Using Smart Features, Zachary P. Friedel
Event-Based Visual-Inertial Odometry Using Smart Features, Zachary P. Friedel
Theses and Dissertations
Event-based cameras are a novel type of visual sensor that operate under a unique paradigm, providing asynchronous data on the log-level changes in light intensity for individual pixels. This hardware-level approach to change detection allows these cameras to achieve ultra-wide dynamic range and high temporal resolution. Furthermore, the advent of convolutional neural networks (CNNs) has led to state-of-the-art navigation solutions that now rival or even surpass human engineered algorithms. The advantages offered by event cameras and CNNs make them excellent tools for visual odometry (VO). This document presents the implementation of a CNN trained to detect and describe features within …
Near Real-Time Zigbee Device Discrimination Using Cb-Dna Features, Yousuke Z. Matsui
Near Real-Time Zigbee Device Discrimination Using Cb-Dna Features, Yousuke Z. Matsui
Theses and Dissertations
Currently, Low-Rate Wireless Personal Area Networks (LR-WPAN) based on the Institute of Electrical and Electronics Engineers (IEEE) 802.15.4 standard are at risk due to open-source tools which allow bad actors to exploit unauthorized network access through various cyberattacks by falsifying bit-level credentials. This research investigates implementing a Radio Frequency (RF) air monitor to perform Near RealTime (NRT) discrimination of Zigbee devices using the IEEE 802.15.4 standard. The air monitor employed a Multiple Discriminant Analysis/Euclidean Distance classifier to discriminate Zigbee devices based upon Constellation-Based Distinct Native Attribute (CB-DNA) fingerprints. Through the use of CB-DNA fingerprints, Physical Layer (PHY) characteristics unique to …
Honeyhive - A Network Intrusion Detection System Framework Utilizing Distributed Internet Of Things Honeypot Sensors, Zachary D. Madison
Honeyhive - A Network Intrusion Detection System Framework Utilizing Distributed Internet Of Things Honeypot Sensors, Zachary D. Madison
Theses and Dissertations
Exploding over the past decade, the number of Internet of Things (IoT) devices connected to the Internet jumped from 3.8 billion in 2015 to 17.8 billion in 2018. Because so many IoT devices remain upatched, unmonitored, and left on, they have become a tantalizing target for attackers to gain network access or add another device to their botnet. HoneyHive is a framework that uses distributed IoT honeypots as Network Intrusion Detection Systems (NIDS) sensors that beacon back to a centralized Command and Control (C2) server. The tests in this experiment involve four types of scans and four levels of active …
Relational Database Design And Multi-Objective Database Queries For Position Navigation And Timing Data, Sean A. Mochocki
Relational Database Design And Multi-Objective Database Queries For Position Navigation And Timing Data, Sean A. Mochocki
Theses and Dissertations
Performing flight tests is a natural part of researching cutting edge sensors and filters for sensor integration. Unfortunately, tests are expensive, and typically take many months of planning. A sensible goal would be to make previously collected data readily available to researchers for future development. The Air Force Institute of Technology (AFIT) has hundreds of data logs potentially available to aid in facilitating further research in the area of navigation. A database would provide a common location where older and newer data sets are available. Such a database must be able to store the sensor data, metadata about the sensors, …
Lightning Prediction For Space Launch Using Machine Learning Based Off Of Electric Field Mills And Lightning Detection And Ranging Data, Anson Cheng
Theses and Dissertations
Kennedy Space Center and Cape Canaveral Air Station, FL, where the Air Force conducts space launches, are in an area of frequent lightning strikes, which is main obstacle in meeting launch goals. The 45th Weather Squadron (45th WS) ensures that any weather safety requirements are met during pre-launch and actual space launch. Using only summer months from three years’ worth of lightning detection and ranging (LDAR) and electric field mill (EFM) data from KSC, several feedforward neural networks are constructed. Separate models are built for each EFM and trained by adjusting parameters to forecast lightning 30 minutes out in the …
Wideband Metasurface Antenna, Thomas A. Lepley
Wideband Metasurface Antenna, Thomas A. Lepley
Theses and Dissertations
This effort explored design of metasurface antennas and evaluated their suitability for ultra-wideband applications (2 to 18 GHz). Six unit cell types were characterized. Eigenmode simulations produced frequency vs. phase data for the unit cells, from which impedance vs. gap size data was computed. A holographic design equation was used to generate the metasurface antenna designs. The unit cell simulations revealed that the assumption of single mode operation is a constraint for wideband designs. An 8" by 8" metasurface antenna with a Rogers 3010 dielectric and a design frequency of 10 GHz was fabricated and tested. It had a 1.5:1 …
Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman
Focused Beam System Biaxial Material Characterization, Nicholas A. O'Gorman
Theses and Dissertations
Electromagnetic material characterization is the process of determining the constitutive parameters (complex permittivity and permeability) of given a sample. Due to the large number of unknowns involved, multiple unique measurements are required for material property extraction. Many measurement methods, such as waveguides and striplines, possess a rigid internal structure that the sample being measured must adhere to. This rigidity limits these methods to samples that fit within the device and inhibits oblique sample orientations, limiting the number of independent measurements that can be obtained. A focus beam system, due to being an open system with greater freedom in sample size …
Extracting Range Data From Images Using Focus Error, Erik M. Madden
Extracting Range Data From Images Using Focus Error, Erik M. Madden
Theses and Dissertations
Air-to-air refueling (AAR) has become a staple when performing long missions with aircraft. With modern technology, however, people have begun to research how to perform this task autonomously. Automated air-to-air refueling (A3R) is this exact concept. Combining many different systems, the idea is to allow computers on the aircraft to link up via the refueling boom, refuel, and detach before resuming pilot control. This document lays out one of the systems that is needed to perform A3R, namely, the system that extracts range data. While stereo cameras perform such tasks, there is interest in finding other ways of accomplishing the …
A Non-Destructive Evaluation Application Using Software Defined Radios And Bandwidth Expansion, Nicholas J. O'Brien
A Non-Destructive Evaluation Application Using Software Defined Radios And Bandwidth Expansion, Nicholas J. O'Brien
Theses and Dissertations
The development of low-complexity, lightweight and low-cost Non-Destructive Evaluation (NDE) equipment for microwave device testing is desirable from a maintenance efficiency and operational availability perspective. Current NDE equipment tends to be custom-designed, cumbersome and expensive. Software Defined Radio (SDR) technology, and a bandwidth expansion technique that exploits a priori transmit signal knowledge and auto-correlation provides a solution. This research investigated the reconstruction of simultaneous SDR receiver instantaneous bandwidth (sub-band) collections using single, dual and multiple SDR receivers. The adjacent sub-bands, collectively spanning a transmit signal bandwidth were auto-correlated with a replica transmit signal to restore frequency and phase offsets. The …
Newhope: A Mobile Implementation Of A Post-Quantum Cryptographic Key Encapsulation Mechanism, Jessica A. Switzler
Newhope: A Mobile Implementation Of A Post-Quantum Cryptographic Key Encapsulation Mechanism, Jessica A. Switzler
Theses and Dissertations
NIST anticipates the appearance of large-scale quantum computers by 2036 [34], which will threaten widely used asymmetric algorithms, National Institute of Standards and Technology (NIST) launched a Post-Quantum Cryptography Standardization Project to find quantum-secure alternatives. NewHope post-quantum cryptography (PQC) key encapsulation mechanism (KEM) is the only Round 2 candidate to simultaneously achieve small key values through the use of a security problem with sufficient confidence its security, while mitigating any known vulnerabilities. This research contributes to NIST project’s overall goal by assessing the platform flexibility and resource requirements of NewHope KEMs on an Android mobile device. The resource requirements analyzed …
A General Methodology To Optimize And Benchmark Edge Devices, Kyle J. Smathers
A General Methodology To Optimize And Benchmark Edge Devices, Kyle J. Smathers
Theses and Dissertations
The explosion of Internet Of Things (IoT), embedded and “smart” devices has also seen the addition of “general purpose” single board computers also referred to as “edge devices.” Determining if one of these generic devices meets the need of a new given task however can be challenging. Software generically written to be portable or plug and play may be too bloated to work properly without significant modification due to much tighter hardware resources. Previous work in this area has been focused on micro or chip-level benchmarking which is mainly useful for chip designers or low level system integrators. A higher …
Predicting Pilot Success Using Machine Learning, Aaron C. Giddings
Predicting Pilot Success Using Machine Learning, Aaron C. Giddings
Theses and Dissertations
The United States Air Force has a pilot shortage. Unfortunately, training an Air Force pilot requires significant time and resources. Thus, diligence and expediency are critical in selecting those pilot candidates with a strong possibility of success. This research applies multivariate and statistical machine learning techniques to pilot candidates pre-qualification test data and undergraduate pilot training results to determine whether there are selected pre-qualification tests or specific training evaluations that do a \best" job of screening for successful pilot training candidates and distinguished graduates. Flight experience, both during training and otherwise, indicates pilot training completion and performance.
Conceptualization And Application Of Deep Learning And Applied Statistics For Flight Plan Recommendation, Nicholas C. Forrest
Conceptualization And Application Of Deep Learning And Applied Statistics For Flight Plan Recommendation, Nicholas C. Forrest
Theses and Dissertations
The Air Forces Pilot Training Next (PTN) program seeks a more efficient pilot training environment emphasizing the use of virtual reality flight simulators alongside periodic real aircraft experience. The PTN program wants to accelerate the training pace and progress in undergraduate pilot training compared to traditional undergraduate pilot training. Currently, instructor pilots spend excessive time planning and scheduling flights. This research focuses on methods to auto-generate the planning of in-flight events using hybrid filtering and deep learning techniques. The resulting approach captures temporal trends of user-specific and program-wide student performance to recommend a feasible set of graded flight events for …
Ground Weather Radar Signal Characterization Through Application Of Convolutional Neural Networks, Stephen M. Lee
Ground Weather Radar Signal Characterization Through Application Of Convolutional Neural Networks, Stephen M. Lee
Theses and Dissertations
The 45th Weather Squadron supports the space launch efforts out of the Kennedy Space Center and Cape Canaveral Air Force Station for the Department of Defense, NASA, and commercial customers through weather assessments. Their assessment of the Lightning Launch Commit Criteria (LLCC) for avoidance of natural and rocket triggered lightning to launch vehicles is critical in approving space shuttle and rocket launches. The LLCC includes standards for cloud formations, which requires proper cloud identification and characterization methods. Accurate reflectivity measurements for ground weather radar are important to meet the LLCC for rocket triggered lightning. Current linear interpolation methods for ground …
Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal
Sortie-Based Aircraft Component Demand Rate To Predict Requirements, Thomas R. O'Neal
Theses and Dissertations
Weapon System Sustainment (WSS) costs are growing at an increasing rate despite the vast efforts to reduce them. Researchers have attributed much of the cost increase to inaccurate demand forecasts for weapon system spare parts. In 2011, the forecast to sustain all United States Air Force (USAF) aircraft was 19% accurate and WSS costs per year have continuously increased. The purpose of this study is to explore a parsimonious change to aircraft component forecasting to reduce costly forecast error. This study substitutes flying hours with sorties for the purpose of demand forecasting. Many F-16 and B-52 spare parts are evaluated …
Mc80: Quantifying Effect Of Fleet Health On Sortie Execution In F-16 Fleet, Kyle R. Gladney
Mc80: Quantifying Effect Of Fleet Health On Sortie Execution In F-16 Fleet, Kyle R. Gladney
Theses and Dissertations
By order of the Secretary of Defense, all of the US Air Force's F-16 units were tasked to improve their fleet health to a Mission Capability (MC) rate of 80 percent, as part of a Department of Defense-wide push to make its Critical Aviation Platforms, and the units that employ them, more ready and lethal. This study uses historical fleet health and sortie execution data captured from LIMS-EV (Weapon System Viewer, 2020) to create a multiple regression model that quantifies the value of increased fleet health, defined as either MC rate or Aircraft Availability (AA) rate, in terms of increasing …
Strategic Sourcing Of Air Force Contingency Pharmaceuticals: A Cost-Benefit Analysis Approach, Adam J. Brubakken
Strategic Sourcing Of Air Force Contingency Pharmaceuticals: A Cost-Benefit Analysis Approach, Adam J. Brubakken
Theses and Dissertations
The purpose of this research is to identify and explore effective supply chain management principles as mitigating measures to improve contingency pharmaceutical item shortfalls in the Air Force Medical Service Contingency Pharmaceutical Program. Analysis of current pharmaceutical shortages demonstrates a significant trend of insufficient demand signals for various pharmaceutical items, resulting in instances of non-fulfillment by private sector suppliers. Through the scope of transaction cost economics, a cost-benefit analysis for various alternatives was conducted. The proposed alternatives evaluated in this thesis include continuation of the status quo, centralized procurement models from a single site, and procurement from regionally designated ordering …
Forecasting Attrition By Afsc For The United States Air Force, Trey S. Pujats
Forecasting Attrition By Afsc For The United States Air Force, Trey S. Pujats
Theses and Dissertations
Retention and personnel management is a challenge for every organization, particularly the military due to its hierarchical structure and barriers to entry. Talent must be developed and retained to become leaders, beginning at the lowest level in the Air Force. The Air Force faces a retention problem unlike most organizations that requires a unique perspective and tailored solution to each Air Force Specialty Code (AFSC). There exists previous efforts to predict attrition rates in the Air Force based on economic factors. This study expands upon the economic factors and tailors the predictor variables of attrition based on the AFSC. The …
Database Analysis To Improve U.S. Transportation Command Forecasting Processes, Maxwell C. Thompson
Database Analysis To Improve U.S. Transportation Command Forecasting Processes, Maxwell C. Thompson
Theses and Dissertations
The United States Transportation Command (USTRANSCOM) facilitates air, land, and sea transportation for the DOD. On a periodic basis, a myriad of different agencies within USTRANSCOM project future workload to facilitate resource planning, budgeting, and reimbursable rate identification. Within USTRANSCOM, there are a variety of databases and metrics utilized for workload forecasts; neither a standard nor a preferred technique is prescribed. Currently, USTRANSCOM faces challenges in producing accurate workload forecasts [1]. These challenges can lead to unreliable budget requests and, ultimately, hinder the effectiveness and efficiency of USTRANSCOM [1]. For the purpose of routine aircraft movements of cargo and personnel, …
Applying Data Organizational Techniques To Enhance Air Force Learning, Jacob A. Orner
Applying Data Organizational Techniques To Enhance Air Force Learning, Jacob A. Orner
Theses and Dissertations
The USAF and the DoD use traditional schoolhouses to educate and train personnel. The physical aspects of these schoolhouses limit throughput. A method to increase throughput is to shift towards an asynchronous learning environment where students move through content at individually. This research introduces a methodology for transforming a set of unstructured documents into an organized TM students can use to orient themselves in a domain. The research identifies learning paths within the TM to create a directed KSAT. We apply this methodology in four case studies, each an education or training course. Using a graph comparison metric and the …
A Study Of Execution Performance For Rust-Based Object Vs Data Oriented Architectures, Joseph A. Vagedes
A Study Of Execution Performance For Rust-Based Object Vs Data Oriented Architectures, Joseph A. Vagedes
Theses and Dissertations
To investigate the Data-Oriented Design (DOD) paradigm, in particular, an architecture built off its principles: the Entity-Component-System (ECS). ECS is commonly used by video game engines due to its ability to store data in a way that is optimal for the cache to access. Additionally, the structure of this paradigm produces a code-base that is simple to parallelize as the workload can be distributed across a thread-pool based on the data used with little to no need for data safety measures such as mutexes and locks. A final benefit, although not easily measured, is that the DOD paradigm produces a …
Multivariate Analysis Of Human Performance Strong Lab Data, Kayla N. Tinucci
Multivariate Analysis Of Human Performance Strong Lab Data, Kayla N. Tinucci
Theses and Dissertations
This study uses multivariate analysis methods to find relationships between nutrition and wellness and nutrition and performance. The nutrition, daily wellness, and weight and bodyfat data are from a study performed by the STRONG lab in the 711th Human Performance Wing. Electronically collected nutrition data along with survey data for 19 individuals over a 12-week study period are examined with a focus on health, fitness, and nutrition. Factor analysis and linear regression are performed and inferences are drawn regarding what effects calories and macronutrient intake have on subjects perceived wellness, weight, and body fat percentage. These insights are discussed in …
An Analysis Of A Lighting Prediction Threshold For 45th Weather Squadron Electric Field Mill Data, Charles A. Skrovan
An Analysis Of A Lighting Prediction Threshold For 45th Weather Squadron Electric Field Mill Data, Charles A. Skrovan
Theses and Dissertations
The mission of the 45th Weather Squadron (45 WS) is to “exploit the weather to assure safe access to air and space” for Patrick Air Force Base, Cape Canaveral Air Force Station (CCAFS), and Kennedy Space Center (KSC) in support of various operations (United States Air Force, n.d.). To support that mission the 45 WS hosts a suite of weather detection instruments that include a lightning warning system that consists of an array of 31 electric field mills (EFM) and a lightning detection and ranging system (Department of the Air Force, 1976). Electric field mills at Cape Canaveral continuously record …
A Metamodel Recommendation System Using Meta-Learning, Megan K. Woods
A Metamodel Recommendation System Using Meta-Learning, Megan K. Woods
Theses and Dissertations
The importance and value of statistical predictions increase as data grows in availability and quantity. Metamodels, or surrogate models, provide the ability to rapidly approximate and predict information. However, selection of the appropriate metamodel for a given dataset is often arduous, and the choice of the wrong metamodel could lead to considerably inaccurate results. This research proposes and tests the framework for a metamodel recommendation system. The implementation allows for virtually any dataset and preprocesses data, calculates meta-features, evaluates the performance of various metamodels, and learns how the data behaves via meta-learning, thus preparing and bettering itself for future recommendations. …
Resilient Aircraft Sustainment: Quantifying Resilience Through Asset And Capacity Allocation, Zachary B. Shannon
Resilient Aircraft Sustainment: Quantifying Resilience Through Asset And Capacity Allocation, Zachary B. Shannon
Theses and Dissertations
Decision makers lack a clear, generalizable method to quantify how additional investment in inventory and capacity equates to additional levels of resilience. This research facilitates a deeper understanding of the intricacies and complex interconnectedness of organizational supply chains by monetarily quantifying changes in network resilience. The developed Area under the Curve metric (AUC) is used to quantify the level of demand that each asset allocation can meet during a disruptive event. Due to its applicability across multiple domains, the USAF F-16 repair network in the Pacific theater (PACAF) is modeled utilizing discrete event simulation and used as the illustrating example. …
Using A Field Mill Climatology To Assess All Lightning Launch Commit Criteria, Shane C. Gardner
Using A Field Mill Climatology To Assess All Lightning Launch Commit Criteria, Shane C. Gardner
Theses and Dissertations
Due to the danger and cost of lightning striking a space vehicle, the Cape Canaveral Air Force Station (CCAFS) balances between the mission of launching and cessation thereof to minimize the risk of a lightning strike. This process is mediated through a set of rules called the Lightning Launch Commit Criteria (LLCC). To date, no empirical modeling of these rules has been established. To alleviate this shortcoming, this thesis uses the voltage readings of the surrounding CCAFS surface field mills to establish the viability of modeling the entirety of the LLCC rules statistically. Converting approximately 312,000,000 field mill voltage readings …
Validation Technique For Modeled Bottomside Ionospheres Via Ray Tracing, Kevin S. Burg
Validation Technique For Modeled Bottomside Ionospheres Via Ray Tracing, Kevin S. Burg
Theses and Dissertations
A new method for validating ionosphere models using High Frequency (HF) angle of arrival (AoA) data is presented. AoA measurements from a field campaign held at White Sands Missile Range, New Mexico, USA in January 2014 provide the actual elevation angle, azimuth and group delay results from 10 transmitter-receiver circuits. Simulated AoAs are calculated by ray tracing through the electron density profiles predicted from the ionosphere models hosted by NASA's Community Coordinated Modeling Center: IRI-2016, USU-GAIM, GITM, CTIPe, TIE-GCM, and SAMI3. Through the implementation of metrics including Mean Absolute Error, Prediction Efficiency, Correlation Coefficient, and others, we are able to …
Investigation Of Ultem 9085 For Use In Printed Orbital Structures, William R. Gallagher
Investigation Of Ultem 9085 For Use In Printed Orbital Structures, William R. Gallagher
Theses and Dissertations
Additive manufacturing is revolutionizing industries ranging from medicine to space. However, the structural characteristics of plastic parts created by these methods are not as well understood as their more established counterparts. This research explored two relevant areas: how the structural characteristics of ULTEM 9085 plastic behaved after exposure to orbital conditions and the design of the cross-sectional area of a beam to be 3-D printed in microgravity based on the expected loads from the printer. To study orbital effects, ULTEM 9085 was printed into 1/4th scale ASTM D638- 14 dogbones using a Stratasys 450mc printer. These dogbones were placed in …