Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Aerospace Engineering (1664)
- Electrical and Computer Engineering (1332)
- Operations Research, Systems Engineering and Industrial Engineering (1238)
- Physical Sciences and Mathematics (1164)
- Operational Research (605)
-
- Signal Processing (455)
- Computer Sciences (443)
- Civil and Environmental Engineering (421)
- Computer Engineering (414)
- Aviation (353)
- Electrical and Electronics (350)
- Physics (350)
- Materials Science and Engineering (329)
- Business (297)
- Navigation, Guidance, Control and Dynamics (250)
- Other Operations Research, Systems Engineering and Industrial Engineering (232)
- Systems Engineering (228)
- Electromagnetics and Photonics (190)
- Aerodynamics and Fluid Mechanics (188)
- Environmental Engineering (185)
- Engineering Science and Materials (176)
- Nuclear Engineering (176)
- Mechanical Engineering (169)
- Digital Communications and Networking (166)
- Space Vehicles (159)
- Optics (147)
- Management and Operations (144)
- Operations and Supply Chain Management (135)
- Semiconductor and Optical Materials (126)
- Keyword
-
- #antcenter (324)
- #csra (125)
- Global Positioning System (63)
- Image processing (61)
- #afcec (60)
-
- Optimization (54)
- Additive manufacturing (51)
- Decision making (51)
- Kalman filtering (51)
- Flight control (48)
- Machine learning (48)
- Target acquisition (47)
- Drone aircraft (46)
- Algorithms (45)
- Microelectromechanical systems (44)
- Composite materials (41)
- Artificial satellites (38)
- Synthetic aperture radar (38)
- Computer vision (37)
- Neural networks (Computer science) (37)
- Computer networks--Security measures (35)
- Signal processing (35)
- Finite element method (33)
- Scheduling (32)
- Simulation (31)
- Decision support systems (30)
- Neural networks (30)
- Remote sensing (28)
- Wireless communication systems (28)
- Silicon carbide (26)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 661 - 690 of 5699
Full-Text Articles in Engineering
Differential Game-Based Defensive Architecture Study Employing Ground-Based Interceptors, Stephen T. Zittrouer
Differential Game-Based Defensive Architecture Study Employing Ground-Based Interceptors, Stephen T. Zittrouer
Theses and Dissertations
A study of defensive architectures for combating hypersonic glide vehicles (HGVs) via interception with a ground-based interceptor (GBI) is presented. Pursuit-evasion differential games are formulated for numerical simulation of the interception engagements. A one-sided optimal control problem wherein the evader HGV is optimized and the pursuer GBI employs a suboptimal proportional navigation control strategy is solved. The solution space is characterized by varying the pursuer initial velocity advantage relative to the evader. A two-sided optimal control problem in which both players behave optimally is solved via the semi-direct collocation with nonlinear programming (semiDCNLP) method. The resulting state and control trajectories …
Aeroelasticity Of Six Degree-Of-Freedom Satellite Bus Configurations During Terminal Reentry, Jinhee F. Byun
Aeroelasticity Of Six Degree-Of-Freedom Satellite Bus Configurations During Terminal Reentry, Jinhee F. Byun
Theses and Dissertations
With disposable equipment on board, the emphasis on structural strength and robust thermal protection system (TPS) pales for a conventional satellite in comparison to reentry capsules, which are specifically designed to withstand the intense aerothermodynamic effects experienced during reentry. In this research, six degree-of-freedom (6DOF) analyses of three distinct non-aerodynamic satellite bus configurations were performed with emphasis on the investigation of their terminal reentry characteristics, and thermal and deceleration loading on the satellite body. Aeroelastic effects on their respective solar panel structures were also analyzed focusing on characterizing bending stress at their attachment/deployment mechanism. It was found that the Terra …
A Proposed Mission Assurance Framework For University Cubesat Programs, Mitchell R. Thomas
A Proposed Mission Assurance Framework For University Cubesat Programs, Mitchell R. Thomas
Theses and Dissertations
The low cost, small form factor, and use of Commercial-Off-The-Shelf components make CubeSats an ideal platform for university use given their unique constraints. Since 2000, roughly 55% of CubeSats developed by universities fail to meet mission goals. Mission assurance, which is used to increase confidence in mission success, is based around traditional government programs, and does not provide an adequate road map for universities. Leaving them without specific guidance in tailoring mission assurance activities to operate within their constraints. This paper adapts these traditional practices to develop a baseline mission assurance framework for university CubeSat programs.
Considerations Using Iterative Closest Point In Presence Of Occlusions In Automated Aerial Refueling, Joel M. Miller
Considerations Using Iterative Closest Point In Presence Of Occlusions In Automated Aerial Refueling, Joel M. Miller
Theses and Dissertations
The United States Air Force is researching vision-based AAR and different methods for this actualization. Previous work has established a computer vision based pipeline with ICP. This work focuses on how ICP can become resilient to boom occlusion by minimizing errors and discusses the limitations of ICP in the face of occlusions. Specifically, we look at various filtering techniques to remove non-salient points. To register point clouds while maintaining real time interactivity, this work also presents a method for downsampling high resolution camera calibrations to preserve real-time processing and significantly decrease the vision pipeline latency.
Monocular Pose Estimation For Automated Aerial Refueling Via Perspective-N-Point, James C. Lynch
Monocular Pose Estimation For Automated Aerial Refueling Via Perspective-N-Point, James C. Lynch
Theses and Dissertations
Any Automated Aerial Refueling (AAR) solution requires the quick and precise estimation of the relative position and rotation of the two aircraft involved. This is currently accomplished using stereo vision techniques augmented by Iterative Closest Point (ICP), but requires post-processing to account for environmental factors such as boom occlusion. This paper proposes a monocular solution, combining a custom-trained single-shot object detection Convolutional Neural Network (CNN) and Perspective-n-Point (PnP) estimation to calculate a pose estimate with a single image. This solution is capable of pose estimation at contact point (22m) within 7cm of error and a rate of 10Hz, regardless of …
Towards The Integration Of Ferroelectric Negative Capacitance With Gallium Oxide Semiconductors For High Power Applications, Guillermo A. Salcedo
Towards The Integration Of Ferroelectric Negative Capacitance With Gallium Oxide Semiconductors For High Power Applications, Guillermo A. Salcedo
Theses and Dissertations
Gallium oxide is a relatively new semiconductor material with characteristics auspicious for high frequency and high-voltage applications. Although several research groups have already demonstrated radio-frequency (RF) devices on Ga2O3 with remarkable features, there is still room for improvement. For instance, the operating frequency of RF field-effect transistors (FET) decreases with the parasitic capacitance, which can be counteracted by higher gate capacitance. Implementing ferroelectric dielectrics with suitable parameters in Ga2O3 FET promises to enhance the gate capacitance and therefore increase operating frequency. This work investigated the effect of various factors (film composition, film thickness, TiN …
Analysis Of Container Shipments For Ustranscom, John N. Campos Y Campos
Analysis Of Container Shipments For Ustranscom, John N. Campos Y Campos
Theses and Dissertations
USTRANSCOM (United States Transportation Command) sends containers to various overseas destinations, mainly commercial container shipping companies. Delivering the containers to the destinations on time is important to support the United States (US) Forces deployed in foreign countries. This study analyzes container shipment records for two years from 2019 to 2021 and prepares insights for USTRANSCOM. This study utilizes descriptive statistics, data visualization, and one-way analysis of variance (ANOVA). According to the records, almost half of the containers (41.25%) were delivered late for one day or longer. The container with the longest delay took 408 days. Major reasons for delays included …
Real Time Evaluation Of Boom And Drogue Occlusion With Aar, Xiaoyang Wu
Real Time Evaluation Of Boom And Drogue Occlusion With Aar, Xiaoyang Wu
Theses and Dissertations
In recent years, Unmanned Aerial Vehicles (UAV) have seen a rise in popularity. Various navigational algorithms have been developed as a solution to estimate a UAV’s pose relative to the refueler aircraft. The result can be used to safely automate aerial refueling (AAR) to improve UAVs’ time-on-station and ensure the success of military operations. This research aims to reach real-time performance using a GPU accelerated approach. It also conducts various experiments to quantify the effects of refueling boom/drogue occlusion and image exposure on the pose estimation pipeline in a lab setting.
Simulating Autonomous Cruise Missile Swarm Behaviors In An Anti-Access Area Denial (A2ad) Environment, Kyle W. Goggins
Simulating Autonomous Cruise Missile Swarm Behaviors In An Anti-Access Area Denial (A2ad) Environment, Kyle W. Goggins
Theses and Dissertations
The increasingly sophisticated anti-access area denial (A2AD) threat imposed by the modern integrated air defense system (IADS), coupled with the decreasingly potent advantage provided by high-end stealth platforms, has prompted Air Force senior leaders to invest in radically changing the nature of air power for the year 2030 and beyond. A prominent element of this new vision is weapon swarming, which aims to address this challenge by overwhelming the IADS with huge numbers of low-cost, attritable aerial assets emboldened by autonomous capabilities. This research proposes a framework for classifying the different levels of autonomous capability along three independent dimensions—namely ability …
Screening Heuristics For The Evaluation Of Covert Network Node Insertion Scenarios, Andrew E. Pekarek
Screening Heuristics For The Evaluation Of Covert Network Node Insertion Scenarios, Andrew E. Pekarek
Theses and Dissertations
The majority of research on covert networks uses social network analysis (SNA) to determine critical members of the network to either kill or capture for the purpose of network destabilization. This thesis takes the opposite approach and evaluates potential scenarios for inserting an agent into a covert network for information gathering purposes or future disruption operations. Due to the substantial number of potential insertion scenarios in a large network, this research proposes three screening heuristics that leverage SNA measures to reduce the solution space before applying a simple search heuristic.
Feasibility Of Fireball Trail Detection Using Ground-Based Gps Receivers, Ian R. Moffett
Feasibility Of Fireball Trail Detection Using Ground-Based Gps Receivers, Ian R. Moffett
Theses and Dissertations
The feasibility of using GPS data to detect fireballs is analyzed by first modeling the fireball’s trail diffusion and plasma chemistry to get a resulting ion density profile of the trail over time. The signal perturbation caused by the fireball trail is simulated for a ground receiver using an analytic solution for diffraction from a Gaussian lens. Five cases were modeled with varying initial peak ion densities and altitudes taken from fireball and reentry vehicle data. This paper shows that it is feasible to detect a fireball trail using GPS if the fireball has a sufficiently high initial ion density, …
Air Force Specialty Code Assignment Optimization, Rebecca L. Reynolds
Air Force Specialty Code Assignment Optimization, Rebecca L. Reynolds
Theses and Dissertations
Each year, the Air Force Personnel Center determines which career field newly commissioned officers will serve under during their time in the Air Force. The career fields are assigned while considering five priorities, dictated by Headquarters Air Force, Manpower and Personnel: target number of cadets, education requirements, average cadet percentile, cadet source of commissioning, and cadet preference. A mixed-integer linear program with elasticized constraints is developed to generate cadet assignments according to these priorities. Each elasticized constraint carries an associated reward and penalty, which is used to dictate the importance of the constraint within the model. A subsequent analysis is …
Analysis Of Generalized Artificial Intelligence Potential Through Reinforcement And Deep Reinforcement Learning Approaches, Jonathan Turner
Analysis Of Generalized Artificial Intelligence Potential Through Reinforcement And Deep Reinforcement Learning Approaches, Jonathan Turner
Theses and Dissertations
Artificial Intelligence is the next competitive domain; the first nation to develop human level artificial intelligence will have an impact similar to the development of the atomic bomb. To maintain the security of the United States and her people, the Department of Defense has funded research into the development of artificial intelligence and its applications. This research uses reinforcement learning and deep reinforcement learning methods as proxies for current and future artificial intelligence agents and to assess potential issues in development. Agent performance were compared across two games and one excursion: Cargo Loading, Tower of Hanoi, and Knapsack Problem, respectively. …
A Decision Support Simulation To Analyze Scheduling Alternatives For Applicant Processing At Military Entrance Processing Stations (Meps), Jonathan M. Escamilla
A Decision Support Simulation To Analyze Scheduling Alternatives For Applicant Processing At Military Entrance Processing Stations (Meps), Jonathan M. Escamilla
Theses and Dissertations
Applicant processing at Military Entrance Processing Stations (MEPS) is conducted via a batch arrival process by which all applicants arrive at the beginning of the processing day. Pursuit of alternate processing scenarios has never progressed beyond the pilot stage, possibly because the Command lacks a general decision support model to evaluate the impacts of proposed policies on applicant processing operations. This research creates a discrete event simulation of MEPS applicant processing operations and applies the model to three alternative applicant processing scenarios: split-shift, appointment- based, and express-lane. Results are examined and compared to benchmarks using multiple performance measurements.
Evaluating The Use Of Boot Image Encryption On Talos Ii Architecture, Calvin M. Muramoto
Evaluating The Use Of Boot Image Encryption On Talos Ii Architecture, Calvin M. Muramoto
Theses and Dissertations
Sensitive devices operating in unprotected environments are vulnerable to hardware attacks like reverse engineering and side channel analysis. This represents a security concern because the root of trust can be invalidated through boot firmware manipulation. For example, boot data is rarely encrypted and typically travels across an accessible bus like the LPC bus, allowing data to be easily intercepted and possibly manipulated during system startup. The ash chip storing the boot data can also be removed from these devices and examined to reveal detailed boot information. This paper details an implementation of encrypting a section of the boot image and …
Qualitative Insights On The Military Entrance Processing Station (Meps) Of Excellence Program, Brian T. Johnson
Qualitative Insights On The Military Entrance Processing Station (Meps) Of Excellence Program, Brian T. Johnson
Theses and Dissertations
The Military Entrance Processing Station (MEPS) of Excellence Program (MOE) is a program to improve operations through recognition and motivation and to sustain excellence in MEPSs core services. Quantitative MOE program data was studied using a hybrid approach of descriptive statistics, statistical process control, and logistic regression to gain relevant insights with respect to the program objectives of improvement, excellence, motivation, and recognition. Future work should employ information such as climate surveys, worker performance reports, and the civilian awards program for further insights into the MOEs effectiveness as a motivator.
Optimal Aircraft Maneuvering Models For Cruise Missile Engagement: A Modeling And Computational Study, Izaiah G. Laduke
Optimal Aircraft Maneuvering Models For Cruise Missile Engagement: A Modeling And Computational Study, Izaiah G. Laduke
Theses and Dissertations
Given the increased threat and proliferation of adversary military capabilities, this research seeks to develop reasonably accurate and computationally tractable models to optimally maneuver aircraft to intercept cruise missile attacks. The research leveraged mathematical programming to model the problem, informed by constraints representing a system of (temporal) difference equations. The research began by comparing six models having alternative representations of velocity and acceleration constraints while analyzing situations with stationary targets. The Multiple Aircraft, Multiple Stationary Target Engagement Problem with Box Constraint Bounds (MAMSTEP-BC) Model yielded superior overall performance and was further analyzed through alternative mathematical programming model enhancements to create …
Applying Models Of Circadian Stimulus To Explore Ideal Lighting Configurations, Alexander J. Price
Applying Models Of Circadian Stimulus To Explore Ideal Lighting Configurations, Alexander J. Price
Theses and Dissertations
Increased levels of time are spent indoors, decreasing human interaction with nature and degrading photoentrainment, the synchronization of circadian rhythms with daylight variation. Military imagery analysts, among other professionals, are required to work in low light level environments to limit power consumption or increase contrast on display screens to improve detail detection. Insufficient exposure to light in these environments results in inadequate photoentrainment which is associated with degraded alertness and negative health effects. Recent research has shown that both the illuminance (i.e., perceived intensity) and wavelength of light affect photoentrainment. Simultaneously, modern lighting technologies have improved our ability to construct …
Game Theory Framework To Evaluate Nuclear Deterrence, Michael A. Cevallos
Game Theory Framework To Evaluate Nuclear Deterrence, Michael A. Cevallos
Theses and Dissertations
This research game theory framework evaluates the resilience of nuclear deterrence options between two players. We use lexicographic prioritization to value four priorities of political, military, economic, and civilian casualties. The value order may be varied. We demonstrate our approach with six player choices of no nuclear strike, demonstration, counterforce, tactical military, economic, or countervalue strike. We use game theory to construct and analyze the resulting damage matrix. We conclude that credible deterrence requires having at least equivalent offensive damage capabilities.
Indicators Of Political Instability In The Presence Of Rapid Urban And Youth Population Growth, Douglas W. Hubbard
Indicators Of Political Instability In The Presence Of Rapid Urban And Youth Population Growth, Douglas W. Hubbard
Theses and Dissertations
Large and rapidly growing cities and other urban agglomerations have the potential to become incubators of political instability. This is especially true of rapidly growing cities which are located in countries that are also experiencing high rates of growth in their youth population. Rapid growth rates put stress on urban infrastructure and other institutions, and these stresses can cause major problems for both city and national governments. Knowing when these cities and countries may be trending toward their tipping points regarding political instability will help governments and international organizations develop and implement effective strategies to mitigate the risk of instability.
Deep Learning Techniques To Estimate 3d Position In Stereoscopic Imagery, Jonathan I. Nicholson
Deep Learning Techniques To Estimate 3d Position In Stereoscopic Imagery, Jonathan I. Nicholson
Theses and Dissertations
Current AAR efforts utilize machine vision algorithms to estimate the pose of a receiver aircraft. However, these algorithms are dependent on several conditions such as the availability of precise 3D aircraft models; the accuracy of the pipeline significantly degrades in the absence of high-quality information given beforehand. We propose a deep learning architecture that estimates the 3D position of an object based on stereoscopic imagery. We investigate the use of both machine learning techniques and neural networks to directly regress the 3D position of the receiver aircraft. We present a new position estimation framework that is based on the differences …
Malware Detection Using Electromagnetic Side-Channel Analysis, Matthew A. Bergstedt
Malware Detection Using Electromagnetic Side-Channel Analysis, Matthew A. Bergstedt
Theses and Dissertations
Many physical systems control or monitor important applications without the capacity to monitor for malware using on-device resources. Thus, it becomes valuable to explore malware detection methods for these systems utilizing external or off-device resources. This research investigates the viability of employing EM SCA to determine whether a performed operation is normal or malicious. A Raspberry Pi 3 was set up as a simulated motor controller with code paths for a normal or malicious operation. While the normal path only calculated the motor speed before updating the motor, the malicious path added a line of code to modify the calculated …
Detection And Identification Of Cellphone Emitted Light Detection And Ranging Light In Security Camera Video Footage, Tristan V. Creek
Detection And Identification Of Cellphone Emitted Light Detection And Ranging Light In Security Camera Video Footage, Tristan V. Creek
Theses and Dissertations
The prevalence of Light Detection and Ranging (LiDAR) sensors in consumer cellphones has ushered in an era of access to technologies previously inaccessible to the average person. Although LiDAR sensors emit light in the infrared spectrum invisible to the naked eye, many security cameras possess the ability to capture infrared light reflected off surfaces to detect LiDAR light in an environment. Once detected and recorded to video footage, current classification methods fail to identify the LiDAR light. Therefore, this research develops a methodology to detect LiDAR light in security camera video footage and identify it as cellphone LiDAR. A proposed …
Exploiting The Iot Through Network-Based Covert Channels, Kyle S. Harris
Exploiting The Iot Through Network-Based Covert Channels, Kyle S. Harris
Theses and Dissertations
Information leaks are a top concern to industry and government leaders. The IoT is a technology capable of sensing real-world events. A method for exfiltrating data from these devices is by covert channel. This research designs a novel IoT CTC without the need for inter-packet delays to encode data. Instead, it encodes data within preexisting network information, namely ports or addresses. Additionally, the CTC can be implemented in two different modes: Stealth and Bandwidth. Performance is measured using throughput and detectability. The Stealth methods mimic legitimate traffic captures while the Bandwidth methods forgo this approach for maximum throughput. Detection results …
Testbed Creation To Study Noise Radar Network Weighting Models And Data Fusion With Radio Tomographic Imaging, Ryan M. Jans
Testbed Creation To Study Noise Radar Network Weighting Models And Data Fusion With Radio Tomographic Imaging, Ryan M. Jans
Theses and Dissertations
Significant research has been conducted on RTI weighting models; however, very little comparative research has been conducted for NRN weighting methods. In order to create comparative weighting methods for NRN, it is necessary to create a testbed which allows for RTI and NRN research to be conducted simultaneously and allow for data fusion methods to also be researched. After creating the testbed and analyzing results, the newly proposed weighting method provides an up to 33% performance increase in target localization accuracy when compared to the previous weighting model used for NRN. The attenuation image resolution improvements resulted in a 79% …
Monocular Camera Localization Using A Bag Of Visual Words From Virtual World Data, Joshua A. Rinaldi
Monocular Camera Localization Using A Bag Of Visual Words From Virtual World Data, Joshua A. Rinaldi
Theses and Dissertations
The Visual Localization problem is the question of how to use visual information to determine the location of the camera that captured that data. The wide availability and low price of RGB cameras has made this useful in many fields such as SLAM, SAM and AR. This research seeks to determine if a BOVW can adequately overcome repetitious features in indoor environments and be effectively incorporated into a VL pipeline.
Military Personnel Flight Customer Wait Time Reduction Model Using Simulation, Nicholas C. Anderson
Military Personnel Flight Customer Wait Time Reduction Model Using Simulation, Nicholas C. Anderson
Theses and Dissertations
Customers at Military Personnel Flights (MPFs) have been experiencing long wait times. These customers are typically employees of the United States Air Force and every moment spent waiting for service is a moment they are away from their actual jobs. By reducing the mean wait time of MPF customers, manhours can be saved and customer complaints may be alleviated. This research uses data collected from an MPF to build a discrete-event simulation model of an MPF. A full factorial experimental design was conducted in the model using five factors. The factors included the total number of employees, the total number …
Narrative Analysis Of Open-Source Social Media Activity In The Indopacom Aor, Aaron K. Glenn
Narrative Analysis Of Open-Source Social Media Activity In The Indopacom Aor, Aaron K. Glenn
Theses and Dissertations
Emotion classification can be a powerful tool to derive narratives from social media data. Recurrent Neural Networks (RNN) can meet or exceed the performance of state-of-the-art traditional machine learning techniques using exclusively open-source data and models. Specifically, these results show that RNN variants can produce more than an 8% gain in accuracy in comparison to Logistic Regression and SVM techniques and a 15% gain over Random Forest when using FastText embeddings. This research found a statistical significance in the performance of a single layer Bi-directional Long Short-Term Memory (Bi-LSTM) model over a 2-layer stacked Bi-LSTM model. This research also found …
Approximate Dynamic Programming For An Unmanned Aerial Vehicle Routing Problem With Obstacles And Stochastic Target Arrivals, Kassie M. Gurnell
Approximate Dynamic Programming For An Unmanned Aerial Vehicle Routing Problem With Obstacles And Stochastic Target Arrivals, Kassie M. Gurnell
Theses and Dissertations
The United States Air Force is investing in artificial intelligence (AI) to speed analysis in efforts to modernize the use of autonomous unmanned combat aerial vehicles (AUCAVs) in strike coordination and reconnaissance (SCAR) missions. This research examines an AUCAVs ability to execute target strikes and provide reconnaissance in a SCAR mission. An orienteering problem is formulated as anMarkov decision process (MDP) model wherein a single AUCAV must optimize its target route to aid in eliminating time-sensitive targets and collect imagery of requested named areas of interest while evading surface-to-air missile (SAM) battery threats imposed as obstacles. The AUCAV adjusts its …
A New Approach To Career Field Matching For Commissioning Air Force Cadets, Daniel Griffen Laird
A New Approach To Career Field Matching For Commissioning Air Force Cadets, Daniel Griffen Laird
Theses and Dissertations
The current method of assigning graduating cadets from the United States Air Force Academy and Reserve Officers' Training Corps (ROTC) detachments to their career fields uses an integer programming model to maximize \global" Air Force utility, subject to several Air Force-defined constraints. This utility evaluates the positive benefit of assigning a certain cadet to a certain career field. This paper discusses the issues with such a model, as well as presents a new, more refined approach to the problem. Rather than provide a one-size-fits-all formulation of this particular assignment problem, a Value-Focused Thinking (VFT) framework is applied, in conjunction with …