Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Engineering (3203)
- Physical Sciences and Mathematics (3074)
- Computer Sciences (1281)
- Physics (961)
- Electrical and Computer Engineering (887)
-
- Aerospace Engineering (786)
- Operations Research, Systems Engineering and Industrial Engineering (738)
- Operational Research (421)
- Business (409)
- Optics (349)
- Signal Processing (343)
- Oceanography and Atmospheric Sciences and Meteorology (283)
- Computer Engineering (243)
- Atomic, Molecular and Optical Physics (211)
- Electrical and Electronics (209)
- Environmental Sciences (194)
- Applied Mathematics (189)
- Civil and Environmental Engineering (189)
- Aviation (186)
- Statistics and Probability (184)
- Information Security (181)
- Social and Behavioral Sciences (170)
- Atmospheric Sciences (167)
- Materials Science and Engineering (167)
- Navigation, Guidance, Control and Dynamics (167)
- Plasma and Beam Physics (156)
- Operations and Supply Chain Management (149)
- Electromagnetics and Photonics (142)
- Artificial Intelligence and Robotics (138)
- Other Operations Research, Systems Engineering and Industrial Engineering (126)
- Keyword
-
- #antcenter (259)
- Machine learning (95)
- #csra (73)
- Algorithms (60)
- Kalman filtering (52)
-
- Computer networks--Security measures (51)
- Image processing (50)
- Neural networks (Computer science) (50)
- Computer security (47)
- Software engineering (47)
- Decision making (45)
- Target acquisition (45)
- Global Positioning System (44)
- Optimization (41)
- Adaptive optics (40)
- Neural networks (40)
- #ctisr (38)
- Remote sensing (36)
- Computer vision (35)
- Drone aircraft (35)
- Synthetic aperture radar (34)
- #afcec (33)
- Artificial intelligence (31)
- Atmospheric turbulence (30)
- Genetic algorithms (29)
- Mathematical optimization (29)
- Flight control (28)
- Object-oriented programming (Computer science) (28)
- Wireless communication systems (28)
- Deep learning (27)
- Publication Year
- Publication
- Publication Type
- File Type
Articles 1951 - 1980 of 5602
Full-Text Articles in Entire DC Network
Potential Energy Curves And Associated Line Shape Of Alkali-Metal And Noble-Gas Interactions, Larry A. Blank
Potential Energy Curves And Associated Line Shape Of Alkali-Metal And Noble-Gas Interactions, Larry A. Blank
Theses and Dissertations
Recent interest in optically-pumped alkali laser systems has prompted this study into the binary interaction potentials between species of alkali-metal and rare-gas atoms and the effects of the collision of these species on the alkali-metal atom absorption spectrum. Special attention is placed on the relationship of the interaction potentials and the resulting line shape. The X2Σ+1/2, A2π1/2, A2π3/2, and B2Σ+1/2 potential energy curves and associated dipole matrix elements are computed for M+ Ng at the spin-orbit multi-reference configuration interaction level, where M = …
Terrain Referenced Navigation Using Sift Features In Lidar Range-Based Data, Matthew T. Leines
Terrain Referenced Navigation Using Sift Features In Lidar Range-Based Data, Matthew T. Leines
Theses and Dissertations
The use of GNSS in aiding navigation has become widespread in aircraft. The long term accuracy of INS are enhanced by frequent updates of the highly precise position estimations GNSS provide. Unfortunately, operational environments exist where constant signal or the requisite number of satellites are unavailable, significantly degraded, or intentionally denied. This thesis describes a novel algorithm that uses scanning LiDAR range data, computer vision features, and a reference database to generate aircraft position estimations to update drifting INS estimates. The algorithm uses a single calibrated scanning LiDAR to sample the range and angle to the ground as an aircraft …
Characterizing And Managing Intrusion Detection System (Ids) Alerts With Multi-Server/Multi-Priority Queuing Theory, Christopher C. Olsen
Characterizing And Managing Intrusion Detection System (Ids) Alerts With Multi-Server/Multi-Priority Queuing Theory, Christopher C. Olsen
Theses and Dissertations
The DoD sets forth an objective to employ an active cyber defense capability to prevent intrusions onto DoD networks and systems. Intrusion Detection Systems (IDS) are a critical part of network defense architectures, but their alerts can be difficult to manage. This research applies Queuing Theory to the management of IDS alerts, seeking to answer how analysts and priority schemes effect alert processing performance. To characterize the effect of these two variables on queue wait times, a MATLAB simulation was developed to allow parametric analysis under two scenarios. The first varies the number of analysts and the second varies the …
Multi-Objective Trajectory Optimization Of A Hypersonic Reconnaissance Vehicle With Temperature Constraints, Tadeusz J. Masternak
Multi-Objective Trajectory Optimization Of A Hypersonic Reconnaissance Vehicle With Temperature Constraints, Tadeusz J. Masternak
Theses and Dissertations
Temperature-constrained optimal trajectories for a scramjet-based hypersonic reconnaissance vehicle were generated by developing an optimal control formulation and solving it using a variable order Gauss-Radau quadrature collocation method. The vehicle was assumed to be an air-breathing reconnaissance aircraft that has specified takeoff/landing locations, airborne refueling constraints, specified no-fly zones, and specified targets for sensor data collections. The aircraft model included fight dynamics, aerodynamics, and thermal constraints. This model was incorporated into an optimal control formulation that includes constraints on both the vehicle as well as mission parameters, such as avoidance of no-fly zones and coverage of high-value targets. Optimal trajectories …
Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez
Cloud-Induced Uncertainty For Visual Navigation, Alyssa N. Gutierrez
Theses and Dissertations
This research addresses the numerical distortion of features due to the presence of clouds in an image. The research aims to quantify the probability of a mismatch between two features in a single image, which will describe the likelihood that a visual navigation system incorrectly tracks a feature throughout an image sequence, leading to position miscalculations. First, an algorithm is developed for calculating transparency of clouds in images at the pixel level. The algorithm determines transparency based on the distance between each pixel color and the average pixel color of the clouds. The algorithm is used to create a dataset …
Approximate Dynamic Programming For Military Resource Allocation, Carl R. Parson
Approximate Dynamic Programming For Military Resource Allocation, Carl R. Parson
Theses and Dissertations
This research considers the optimal allocation of weapons to a collection of targets with the objective of maximizing the value of destroyed targets. The weapon-target assignment (WTA) problem is a classic non-linear combinatorial optimization problem with an extensive history in operations research literature. The dynamic weapon target assignment (DWTA) problem aims to assign weapons optimally over time using the information gained to improve the outcome of their engagements. This research investigates various formulations of the DWTA problem and develops algorithms for their solution. Finally, an embedded optimization problem is introduced in which optimization of the multi-stage DWTA is used to …
A Function-To-Task Process Model For Adaptive Automation System Design, Jason M. Bindewald, Michael E. Miller, Gilbert L. Peterson
A Function-To-Task Process Model For Adaptive Automation System Design, Jason M. Bindewald, Michael E. Miller, Gilbert L. Peterson
Faculty Publications
Adaptive automation systems allow the user to complete a task seamlessly with a computer performing tasks at which the human operator struggles. Unlike traditional systems that allocate functions to either the human or the machine, adaptive automation varies the allocation of functions during system operation. Creating these systems requires designers to consider issues not present during static system development. To assist in adaptive automation system design, this paper presents the concept of inherent tasks and takes advantage of this concept to create the function-to-task design process model. This process model helps the designer determine how to allocate functions to the …
Upward Flow Constructed Wetland For Treatment Of Water Contaminated With Chlorinated Aliphatics, Michael Shelley, Abinash Agrawal, Ke Qin, Garrett Struckhoff, Carl Enfield, James Waldron, Christina Powell
Upward Flow Constructed Wetland For Treatment Of Water Contaminated With Chlorinated Aliphatics, Michael Shelley, Abinash Agrawal, Ke Qin, Garrett Struckhoff, Carl Enfield, James Waldron, Christina Powell
AFIT Patents
An improved upward flow constructed wetland cell for treatment of water contaminated with chlorinated aliphatics is disclosed. The improvements include adding ammonia-oxidizing microorganisms to the methane-oxidizing microorganisms already present in an oxygenated root zone and adding improved pore-water sample chambers for measuring the performance of the constructed wetland cell.
The Lp Relaxation Orthogonal Array Polytope And Its Permutation Symmetries, Andrew J. Geyer, Dursun A. Bulutoglu, Steven J. Rosenberg
The Lp Relaxation Orthogonal Array Polytope And Its Permutation Symmetries, Andrew J. Geyer, Dursun A. Bulutoglu, Steven J. Rosenberg
Faculty Publications
Symmetry plays a fundamental role in design of experiments. In particular, symmetries of factorial designs that preserve their statistical properties are exploited to find designs with the best statistical properties. By using a result proved by Rosenberg [6], the concept of the LP relaxation orthogonal array polytope is developed and studied. A complete characterization of the permutation symmetry group of this polytope is made. Also, this characterization is verified computationally for many cases. Finally, a proof is provided.
Machine Learning Nuclear Detonation Features, Daniel T. Schmitt, Gilbert L. Peterson
Machine Learning Nuclear Detonation Features, Daniel T. Schmitt, Gilbert L. Peterson
Faculty Publications
Nuclear explosion yield estimation equations based on a 3D model of the explosion volume will have a lower uncertainty than radius based estimation. To accurately collect data for a volume model of atmospheric explosions requires building a 3D representation from 2D images. The majority of 3D reconstruction algorithms use the SIFT (scale-invariant feature transform) feature detection algorithm which works best on feature-rich objects with continuous angular collections. These assumptions are different from the archive of nuclear explosions that have only 3 points of view. This paper reduces 300 dimensions derived from an image based on Fourier analysis and five edge …
Timing Mark Detection On Nuclear Detonation Video, Daniel T. Schmitt, Gilbert L. Peterson
Timing Mark Detection On Nuclear Detonation Video, Daniel T. Schmitt, Gilbert L. Peterson
Faculty Publications
During the 1950s and 1960s the United States conducted and filmed over 200 atmospheric nuclear tests establishing the foundations of atmospheric nuclear detonation behavior. Each explosion was documented with about 20 videos from three or four points of view. Synthesizing the videos into a 3D video will improve yield estimates and reduce error factors. The videos were captured at a nominal 2500 frames per second, but range from 2300-3100 frames per second during operation. In order to combine them into one 3D video, individual video frames need to be correlated in time with each other. When the videos were captured …
Nation-Building Modeling And Resource Allocation Via Dynamic Programming, Cade M. Saie
Nation-Building Modeling And Resource Allocation Via Dynamic Programming, Cade M. Saie
Theses and Dissertations
Dynamic programming is used in many military and industrial applications to solve sequential decision making problems. This research proposes the development of a model and approach to address the application of dynamic programming in nation-building modeling. Through the creation of component indices to capture the state of operational variables: Political, Military, Economic, Social, Infrastructure, and Information (PMESII), a functional form of a system of differential equations is developed to account for the interactions between the state indices and instruments of national power: Diplomatic, Informational, Military, and Economic (DIME). Solving this problem with dynamic programming provides an improved sequence which describes …
Improved Wireless Security Through Physical Layer Protocol Manipulation And Radio Frequency Fingerprinting, Benjamin W. Ramsey
Improved Wireless Security Through Physical Layer Protocol Manipulation And Radio Frequency Fingerprinting, Benjamin W. Ramsey
Theses and Dissertations
Wireless networks are particularly vulnerable to spoofing and route poisoning attacks due to the contested transmission medium. Traditional bit-layer defenses including encryption keys and MAC address control lists are vulnerable to extraction and identity spoofing, respectively. This dissertation explores three novel strategies to leverage the wireless physical layer to improve security in low-rate wireless personal area networks. The first, physical layer protocol manipulation, identifies true transceiver design within remote devices through analysis of replies in response to packets transmitted with modified physical layer headers. Results herein demonstrate a methodology that correctly differentiates among six IEEE 802.15.4 transceiver classes with greater …
Statistical Inference On Optimal Points To Evaluate Multi-State Classification Systems, Katherine A. Batterton
Statistical Inference On Optimal Points To Evaluate Multi-State Classification Systems, Katherine A. Batterton
Theses and Dissertations
In decision making, an optimal point represents the settings for which a classification system should be operated to achieve maximum performance. Clearly, these optimal points are of great importance in classification theory. Not only is the selection of the optimal point of interest, but quantifying the uncertainty in the optimal point and its performance is also important. The Youden index is a metric currently employed for selection and performance quantification of optimal points for classification system families. The Youden index quantifies the correct classification rates of a classification system, and its confidence interval quantifies the uncertainty in this measurement. This …
Advances In Sca And Rf-Dna Fingerprinting Through Enhanced Linear Regression Attacks And Application Of Random Forest Classifiers, Hiren J. Patel
Advances In Sca And Rf-Dna Fingerprinting Through Enhanced Linear Regression Attacks And Application Of Random Forest Classifiers, Hiren J. Patel
Theses and Dissertations
Radio Frequency (RF) emissions from electronic devices expose security vulnerabilities that can be used by an attacker to extract otherwise unobtainable information. Two realms of study were investigated here, including the exploitation of 1) unintentional RF emissions in the field of Side Channel Analysis (SCA), and 2) intentional RF emissions from physical devices in the field of RF-Distinct Native Attribute (RF-DNA) fingerprinting. Statistical analysis on the linear model fit to measured SCA data in Linear Regression Attacks (LRA) improved performance, achieving 98% success rate for AES key-byte identification from unintentional emissions. However, the presence of non-Gaussian noise required the use …
Nondestructive Electromagnetic Characterization Of Uniaxial Materials, Neil G. Rogers
Nondestructive Electromagnetic Characterization Of Uniaxial Materials, Neil G. Rogers
Theses and Dissertations
In this dissertation, a method for the simultaneous non-destructive extraction of the permittivity and permeability of a dielectric magnetic uniaxial anisotropic media is developed and several key contributions are demonstrated. The method utilizes a single fixture in which the MUT is clamped between two rectangular waveguides with 6 x 6 PEC flanges. The transmission and reflection coefficients are measured, then compared with theoretically calculated coefficients to find a least squares solution to the minimization problem. One of the key contributions of this work is the development of the total parallel plate spectral-domain Green's function by two independent methods. The Green's …
Investigating Time And Spectral Dependence In Neutron Radiation Environments For Semiconductor Damage Studies, Matthew R. Halstead
Investigating Time And Spectral Dependence In Neutron Radiation Environments For Semiconductor Damage Studies, Matthew R. Halstead
Theses and Dissertations
As legacy neutron irradiation facilities are shut down due to security and financial constrictions, a growing need arises for alternatives that can provide the same or similar radiation environments using methods and/or fuels that do not pose the same risks. For this reason, facilities that provide much lower neutron fluxes and different spectral shapes are being leveraged over longer irradiation intervals to meet this need. However, the question arises as to whether the use of these types of facilities provide a valid comparison to the legacy systems' results. To this end, a model using a system of coupled, non-linear ordinary …
Development Of Imaging Fourier-Transform Spectroscopy For The Characterization Of Turbulent Jet Flames, Jacob L. Harley
Development Of Imaging Fourier-Transform Spectroscopy For The Characterization Of Turbulent Jet Flames, Jacob L. Harley
Theses and Dissertations
Recent advances in computational models to simulate turbulent, reactive flow fields have outpaced the ability to collect highly constraining data--throughout the entire flow field--for validating and improving such models. In particular, the ability to quantify in three dimensions both the mean scalar fields (i.e. temperature & species concentrations) and their respective fluctuation statistics via hyperspectral imaging would be a game-changing advancement in combustion diagnostics, with high impact in both validation and improvement efforts for computational combustion models. This research effort establishes imaging Fourier-transform spectrometry (IFTS) as a valuable tool (which complements laser diagnostics) for the study of turbulent combustion. Specifically, …
Exploring Heuristics For The Vehicle Routing Problem With Split Deliveries And Time Windows, Marcus E. Mcnabb
Exploring Heuristics For The Vehicle Routing Problem With Split Deliveries And Time Windows, Marcus E. Mcnabb
Theses and Dissertations
This dissertation investigates the Vehicle Routing Problem with Split Deliveries and Time Windows. This problem assumes a depot of homogeneous vehicles and set of customers with deterministic demands requiring delivery. Split deliveries allow multiple visits to a customer and time windows restrict the time during which a delivery can be made. Several construction and local search heuristics are tested to determine their relative usefulness in generating solutions for this problem. This research shows a particular subset of the local search operators is particularly influential on solution quality and run time. Conversely, the construction heuristics tested do not significantly impact either. …
Dynamic Bayesian Networks As A Probabilistic Metamodel For Combat Simulations, Clayton T. Kelleher
Dynamic Bayesian Networks As A Probabilistic Metamodel For Combat Simulations, Clayton T. Kelleher
Theses and Dissertations
Simulation modeling is used in many situations. Simulation meta-modeling is used to estimate a simulation model result by representing the space of simulation model responses. Metamodeling methods are particularly useful when the simulation model is not particularly suited to real-time or mean real-time use. Most metamodeling methods provide expected value responses while some situations need probabilistic responses. This research establishes the viability of Dynamic Bayesian Networks for simulation metamodeling, those situations needing probabilistic responses. A bootstrapping method is introduced to reduce simulation data requirement for a DBN, and experimental design is shown to benefit a DBN used to represent a …
Enterprise Analysis Of Strategic Airlift To Obtain Competitive Advantage Through Fuel Efficiency, Adam D. Reiman
Enterprise Analysis Of Strategic Airlift To Obtain Competitive Advantage Through Fuel Efficiency, Adam D. Reiman
Theses and Dissertations
The rising cost of fuel has led to increasing emphasis on fuel efficiency in the aviation industry. As fuel costs become a larger proportion of total costs, those entities with a dynamic capability to increase their fuel efficiency will obtain competitive advantage. Assessing cargo throughput and fuel efficiency requires the creation of all routes of potential value for a given set of requirements that need to be airlifted from source to destination airfield. The time required for route computation can be significantly reduced through the use of nodal reduction. Use of the proposed model can assist evaluation of enterprise wide …
Navigation Solution For A Multiple Satellite And Multiple Ground Architecture, Abraham M. Leigh
Navigation Solution For A Multiple Satellite And Multiple Ground Architecture, Abraham M. Leigh
Theses and Dissertations
This research presents the phased development of an algorithm to plan impulsive orbital maneuvers based on the relative motion between multiple satellites and multiple ground locations. The algorithm leverages the state transition matrix derived from the equations of motion and the equations of variation for the non-spherical Earth and air drag effects. The algorithm determines the impulsive maneuver to achieve the user-defined terminal conditions. The first phase solves for the first burn of an orbital transfer between user-defined altitudes. The optimum trajectory is determined and compared to the first burn in a Hohmann Transfer. The results are expanded to include …
Stochastic Prediction And Feedback Control Of Router Queue Size In A Virtual Network Environment, Muflih Alqahtani
Stochastic Prediction And Feedback Control Of Router Queue Size In A Virtual Network Environment, Muflih Alqahtani
Theses and Dissertations
Modern congestion and routing management algorithms work well for networks with static topologies and moderate QoS requirements. However, these algorithms may not be suitable for modern military networks with fluid dynamic topologies and traffic demands that include mobile networks with many assets. These secure networks require a high level of Quality of Service (QoS) that must adapt to changing demands with no service interruptions. The idea of a network weatherman was developed by Stuckey to predict router queue size by using an extended Kalman filter. He modeled and exercised his design in OPNET with positive results. The goal of this …
Integration Of A Star Tracker And Inertial Sensors Using An Attitude Update, Humood Alkhaldi
Integration Of A Star Tracker And Inertial Sensors Using An Attitude Update, Humood Alkhaldi
Theses and Dissertations
The Global Positioning System (GPS) is widely used in most of the military and civilian applications because of its precision navigation capability. Unfortunately, GPS is not available in all environments (e.g., indoors, under sea, under ground, or jamming environment). The motivation of this research is to address the limitations of GPS by using star trackers as an attitude update to an inertial navigation systems (INS). Commercial, tactical, and navigation grade INS are modeled and simulated with measurements from GPS, star tracker, and barometer. GPS measurements are used to update the INS position and velocity for a small duration in the …
Conceptual Modeling Of A Quantum Key Distribution Simulation Framework Using The Discrete Event System Specification, Jeffrey D. Morris
Conceptual Modeling Of A Quantum Key Distribution Simulation Framework Using The Discrete Event System Specification, Jeffrey D. Morris
Theses and Dissertations
Quantum Key Distribution (QKD) is a revolutionary security technology that exploits the laws of quantum mechanics to achieve information-theoretical secure key exchange. QKD is suitable for use in applications that require high security such as those found in certain commercial, governmental, and military domains. As QKD is a new technology, there is a need to develop a robust quantum communication modeling and simulation framework to support the analysis of QKD systems. This dissertation presents conceptual modeling QKD system components using the Discrete Event System Specification (DEVS) formalism to assure the component models are provably composable and exhibit temporal behavior independent …
Capturing Uncertainty In Fatigue Life Data, Brent D. Russell
Capturing Uncertainty In Fatigue Life Data, Brent D. Russell
Theses and Dissertations
Time-to-failure (TTF) data, also referred to as life data, are investigated across a wide range of scientific disciplines and collected mainly through scientific experiments with the main objective of predicting performance in service conditions. Fatigue life data are times, measured in cycles, until complete fracture of a material in response to a cyclical loading. Fatigue life data have large variation, which is often overlooked or not rigorously investigated when developing predictive life models. This research develops a statistical model to capture dispersion in fatigue life data which can be used to extend deterministic life models into probabilistic life models. Additionally, …
Extending Differential Fault Analysis To Dynamic S-Box Advanced Encryption Standard Implementations, Bradley M. Flamm
Extending Differential Fault Analysis To Dynamic S-Box Advanced Encryption Standard Implementations, Bradley M. Flamm
Theses and Dissertations
Advanced Encryption Standard (AES) is a worldwide cryptographic standard for symmetric key cryptography. Many attacks try to exploit inherent weaknesses in the algorithm or use side channels to reduce entropy. At the same time, researchers strive to enhance AES and mitigate these growing threats. This paper researches the extension of existing Differential Fault Analysis (DFA) attacks, a family of side channel attacks, on standard AES to Dynamic S-box AES research implementations. Theoretical analysis reveals an expected average keyspace reduction of 2-88:9323 after one faulty ciphertext using DFA on the State of Rotational S-box AES-128 implementations. Experimental results revealed an average …
Effects Of Dynamically Weighting Autonomous Rules In A Uas Flocking Model, Jennifer N. Kaiser
Effects Of Dynamically Weighting Autonomous Rules In A Uas Flocking Model, Jennifer N. Kaiser
Theses and Dissertations
Within the U.S. military, senior decision-makers and researchers alike have postulated that vast improvements could be made to current Unmanned Aircraft Systems (UAS) Concepts of Operation through inclusion of autonomous flocking. Myriad methods of implementation and desirable mission sets for this technology have been identified in the literature; however, this thesis posits that specific missions and behaviors are best suited for autonomous military flocking implementations. Adding to Craig Reynolds' basic theory that three naturally observed rules can be used as building blocks for simulating flocking behavior, new rules are proposed and defined in the development of an autonomous flocking UAS …
Simulation Platform For Vision Aided Inertial Navigation, Jason Png
Simulation Platform For Vision Aided Inertial Navigation, Jason Png
Theses and Dissertations
Integrated Inertial Navigation System (INS) and Global Positioning System (GPS) solutions have become the backbone of many modern positioning and navigation systems. The Achilles' heel of such systems are their susceptibility to GPS outages. Hence, there has been sustained interest in alternate navigation techniques to augment a GPS/INS system. With the advancement in camera technologies, visual odometry is a suitable technique. As the cost and effort required to conduct physical trials on a visual odometry system is extensive, this research seeks to provide a simulation platform that is capable of simulating different grades of GPS/INS systems under various realistic visual …
Crack Initiation And Growth Behavior At Corrosion Pit In 2024-T3 Aluminum Alloy, Ibrahim Al-Qahtani
Crack Initiation And Growth Behavior At Corrosion Pit In 2024-T3 Aluminum Alloy, Ibrahim Al-Qahtani
Theses and Dissertations
In this research, fatigue crack formation from two types of corrosion pits at a circular hole was investigated under uniaxial fatigue. Through pits and corner pits were created on the edge of a circular hole in test specimens using an electrochemical process. Specimens of 2024-T3 aluminum alloy were subjected to cyclic uniaxial loads with stress ratio of R = 0.5 in both air and saltwater environments. A fracture mechanics approach was used to investigate the crack initiation and crack growth from corrosion pits. Specimens with a through pit at the edge of a circular hole had a closed form solution …