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Towards Hardware-Based Application Fingerprinting with Microarchitectural Signals for Zero Trust Environments
Get PDFThe interactions between software and hardware are increasingly important to computer system security. This research collects sequences of microprocessor control signals to develop machine learning models that identify software tasks. The proposed approach considers software task identification in hardware as a general problem with attacks treated as a subset of software tasks. Two lines of effort are presented. First, a data collection approach is described to extract sequences of control signals labeled by task identity during real (i.e., non-simulated) system operation. Second, experimental design is used to select hardware and software configuration to train and evaluate machine learning models. The machine learning models significantly outperform a Naive classifier based on Euclidean distances from class means. Various configurations produce balanced accuracy scores between 26.08% and 96.89%
Human Microbiome Transfer in the Built Environment Differs Based on Occupants, Objects, and Buildings
Get PDFCompared to microbiomes on other skin sites, the bacterial microbiome of the human hand has been found to have greater variability across time. To increase understanding regarding the longitudinal transfer of the hand microbiome to objects in the built environment, and vice versa, 22 participants provided skin microbiome samples from their dominant hands, as well as from frequently and infrequently touched objects in their office environments. Additional longitudinal samples from home environments were obtained from a subset of 11 participants. We observed stability of the microbiomes of both the hand and built environments within the office and home settings; however, differences in the microbial communities were detected across the two built environments. Occupants’ frequency of touching an object correlated to that object having a higher relative abundance of human microbes, yet the percent of shared microbes was variable by participants. Finally, objects that were horizontal surfaces in the built environment had higher microbial diversity as compared to objects and the occupants’ hands. This study adds to the existing knowledge of microbiomes of the built environment, enables more detailed studies of indoor microbial transfer, and contributes to future models and building interventions to reduce negative outcomes and improve health and well-being
Thermal Blooming with Laser-induced Convection: Radial Basis Function Simulation
Get PDFThe propagation of a high energy laser through a nearly stagnant absorbing medium is studied. The absorption values and time scale of the problem are such that the laser induces convective heat currents transverse to the beam. These currents couple to the laser via the refractive index, causing time dependent thermal blooming. A numerical method is developed and applied to the model in [ J. Electromagn. Waves Appl. 33, 96 (2019) ], using radial basis functions for spatial differencing, which allows for irregular point spacings and a wide class of geometries. Both the beam and laser-induced fluid dynamics are numerically simulated. These simulations are compared to a historical experiment of a 300 W laser in a smoke-filled chamber with good agreement; both cases include a crescent shaped spot at the target
Development of a Methodology for the Quantification of Reaerosolization of a Biological Contaminate Surrogate Particle from a Military Uniform Fabric
Get PDFIn a mass casualty medical evacuation after a bioaerosol (BA) dispersal event, a decontamination (DC) method is needed that can both decontaminate and prevent biological particle (BP) re-aerosolization (RA) of contaminated clothes. However, neither the efficacy of current DC methods nor the risk of BP RA is greatly explored in the existing literature. The goals of this study were to develop a repeatable method to quantify the RA of a biological contaminant off military uniform fabric swatches and to test the efficacy of one DC protocol (high-volume, low-pressure water) using 1 µm polystyrene latex (PSL) spheres as a surrogate. A four-step methodology was developed: contamination using a Collison Nebulizer; RA using a laboratory mixer and aerosol collection using an inhalable air sampler with a polyvinyl chloride filter; DC using a gravity-fed water shower; and quantification using ultraviolet microscopy via both visual and computer techniques. All results for uncontaminated control samples showed little to no presence of PSL sphere-like particles, while the contaminated experimental trials showed that RA was much lower after DC with water at the 99% confidence level (p-value = 0.0081). The water DC showed an average ∼73% reduction in particle RA, along with a change in air sampler filter deposition patterns from aerosol-like (before DC) to droplet-like (after DC). The fluorescent sphere contamination method for testing the DC residual risk of RA was repeatable and successful
Pulsed Power Neutron Production with Deuterated Polymer Accelerator Targets
Get PDFThis document presents an investigation of the effect of deuterated polyethylene accelerator targets on the neutron fluence from a local mass injection dense plasma focus driven by the United States Naval Research Laboratory’s Hawk pulsed-power generator. After successful production of thin targets, the acquisition of thicker targets, and testing inside Hawk, it was found that the presence of a deuterated polyethylene target increased the neutron fluence. Results suggested that fluence can significantly increase with the presence of a deuterated target vs a nondeuterated target. Additive manufacturing printing was used as a production method in order to determine if deuterated accelerator targets can be 3D printed and if yield is significantly different from the traditional method of thin-film casting. Specifically, photopolymerization-based 3D printing was performed, and it successfully produced both deuterated and nondeuterated polymer targets in disc and cone geometries. Results were inconclusive with regard to the relationship between deuterated 3D printed targets and increased neutron production, but diagnostic analysis revealed correlations between increased chamber voltage, plastic scintillator photomultiplier tube voltage, power delivered at time of pinch, and sodium iodide scintillator counts with increased neutron production. The targets showed impressive durability and the potential for reusability. However, the deuteration of the targets proved to be insufficient to overcome the inherent uncertainty of the bubble detectors and the bubble counting software. Increasing the deuterium atom fraction of the deuterated compound along with increasing the mass fraction of the deuterated compound within the mixed printing material are the hypothesized primary methods by which the deuteration-neutron fluence relationship may be more effectively investigated in future works
Fabrication and Testing of a Novel Layered Metascintillator for Neutron and Gamma Discrimination
Get PDFBy leveraging new developments in fast-curing of plastic scintillators, it is possible to fabricate multi-material plastic scintillators, or metascintillators, which offer improved and/or novel capabilities for radiation detection. This document proposes one geometry of metascintillator that uses layers of green and blue scintillating material to discriminate neutron/gamma radiation, details the devices necessary to fabricate it, and analyzes the metascintillator’s response to radiation. A model of the metascintillator using Geant4 and Python suggested that spectral-based neutron/gamma event discrimination is possible with 63% of gamma events and only 1% of neutron events being multi-color. Fabrication of a 500 µm per layer metascintillator was successful, as well as design and implementation of unique light collection mechanisms that allow for effective measurement of the two-color metascintillator. Exalite-416 and 3-Hydroxyflavone were used to produce blue and green emission light, respectively. Results on neutron/gamma discrimination were inconclusive
Measuring Radiation Protection: Partners from Across the Nuclear Enterprise Evaluate the Radiation Protection of US Army Vehicles
Get PDFRecent mounting nuclear threats and postures from adversary nation-states, such as Russia, China, North Korea, and Iran, represent a clear danger to the interests and security of the United States of America and its Allies. To meet these threats, the 2022 Nuclear Posture Review requires the Department of Defense (DoD) to design, develop, and manage a combat-credible U.S. military which, among other prioritizations, is survivable. A survivable force can generate combat power despite adversary attacks. As such, the US Army must prepare today to set the conditions for successful conventional warfare on the nuclear battlefields of tomorrow. Our Army cannot afford to project weakness, uncertainty, or vulnerability in the attainment of decisive victory over enemy forces on the ground, even when pursuant to hostile nuclear weapon employment
Robust Feature Matching for Visual-based Aerial Navigation Using Registered Imagery
Get PDFThis work leverages the SIFT detector along with known robust feature matching techniques for vision-aided sUAS navigation solutions. The proposed algorithm focuses on a sufficient number of features extracted, their quality and their distribution
Strategic Action Execution Through Regret Matching In Press Diplomacy
Get PDFTo take most advantage of collaboration, negotiation is paramount to succeed in press Diplomacy. Humans use this construct to work towards self victory or sometimes towards an alternative strategic objective undefined in the game’s rules. To emulate this behavior, this thesis examines how to use communication to enable the victory or defeat of any other player in the game. This research develops a press Diplomacy agent, Lyre, that can work to attain these specific objectives in Diplomacy through the regret matching algorithm (RM). We also study how Lyre can begin Diplomacy with the goal to win, then shift strategies to support a different power once its believes victory is infeasible - emulating the human “kingmaking” behavior. Our results indicate Lyre’s success against pre-existing baselines and against alternatives to RM at achieving personal victory or completion of alternative strategic objectives. This shows the utility of RM and the potential for Diplomacy as a serious game to practice wargaming in an environment with unpredictable opponents