Abstract: A spar buoy for very low frequency (VLF) or low frequency (LF) transmission including a first portion of the spar buoy extending above a mean water line including a conductive structure including a coaxial feed, and an antenna coupled to the coaxial feed and extending above the conductive structure, and a second portion of the spar buoy below the mean water line including a transmitter coupled to the coaxial feed, an energy storage subsystem coupled to the transmitter and an electric power generation subsystem coupled to the energy storage subsystem.

Abstract: Described is a learning system for multi-agent applications. In operation, the system initializes a plurality of learning agents. The learning agents include both tactical agents and strategic agents. The strategic agents take an observation from an environment and select one or more of the tactical agents to produce an action that is used to control a platform's actuators or simulated movements in the environment to complete a task. Alternatively, the tactical agents produce the action corresponding to a learned low-level behavior to control the platform's actuators or simulated movements in the environment to complete the task.

Abstract: Some variations provide a magnetically anisotropic structure comprising a hexaferrite film disposed on a substrate, wherein the hexaferrite film contains a plurality of discrete and aligned magnetic hexaferrite particles, wherein the hexaferrite film is characterized by an average film thickness from about 1 micron to about 500 microns, and wherein the hexaferrite film contains less than 2 wt % organic matter. The hexaferrite film does not require a binder. Discrete particles are not sintered or annealed together because the maximum processing temperature to fabricate the structure is 500° C. or less, such as 250° C. or less. The magnetic hexaferrite particles may contain barium hexaferrite (BaFe12O19) and/or strontium hexaferrite (SrFe12O19). The hexaferrite film may be characterized by a remanence-to-saturation magnetization ratio of at least 0.7. Methods of making and using the magnetically anisotropic structure are also described.

Abstract: Described is a system for improving machine operation performance. The system assigns and displays, on an interface having multiple interactive controls, a performance score for each skill of a sequential task in a simulation of operation of a machine. Based on the performance scores, one or more skills to improve with targeted training are identified and displayed on the interface. A training scenario of skills to perform via the interactive controls in a subsequent simulation is recommended to improve the performance scores. Following performance of the training scenario in the subsequent simulation, the system assigns and displays, on the interface, a new performance score for each skill performed. The training scenario is adapted based on the new performance scores.

Abstract: One or more embodiments of the present disclosure are directed toward improved methods of fabricating a semiconductor device utilizing multi-level electron beam lithography (e-beam lithography), an alignment marker for multi-level e-beam lithography, and a semiconductor device including the alignment marker. A method of fabricating a semiconductor device may include: forming an alignment marker in a substrate, the alignment marker including tantalum; determining, utilizing a backscatter electron detector of an electron beam lithography tool, a location of an edge of the alignment marker based on an atomic number contrast between the alignment marker and the substrate; and forming, utilizing the electron beam lithography tool, at least one transistor in the substrate based on the location of the edge of the alignment marker.

Abstract: Some variations provide a system for producing a functionalized powder, comprising: an agitated pressure vessel; first particles and second particles contained within the agitated pressure vessel; a fluid contained within the agitated pressure vessel; an exhaust line for releasing the fluid from the agitated pressure vessel; and a means for recovering a functionalized powder containing the second particles disposed onto surfaces of the first particles. A preferred fluid is carbon dioxide in liquefied or supercritical form. The carbon dioxide may be initially loaded into the pressure vessel as solid carbon dioxide. The pressure vessel may be batch or continuous and is operated under reaction conditions to functionalize the first particles with the second particles, thereby producing a functionalized powder, such as nanofunctionalized metal particles in which nanoparticles act as grain refiners for a component ultimately produced from the nanofunctionalized metal particles.

Abstract: An antimicrobial coating is disclosed that provides fast transport rates of biocides for better effectiveness to deactivate SARS-CoV-2 and other viruses or bacteria on common surfaces. Some variations provide an antimicrobial structure comprising: a solid structural phase comprising a solid structural material; a continuous transport phase that is interspersed within the solid structural phase, wherein the continuous transport phase comprises a solid transport material; and an antimicrobial agent contained within the continuous transport phase, wherein the solid structural phase and the continuous transport phase are separated by an average phase-separation length from about 100 nanometers to about 500 microns. The antimicrobial structure is capable of destroying at least 99.99% of bacteria and/or viruses in 10 minutes of contact. Many options are disclosed for suitable materials to form the solid structural phase, the continuous transport phase, and the antimicrobial agent.

Abstract: The disclosed technology provides a vitrimeric poly(diketoenamine) network comprising: a plurality of multifunctional triketone dimers; a plurality of multifunctional amine species containing primary or secondary amine groups, but no tertiary amine groups; and optionally, one or more amine-reactive groups. The disclosed technology also provides a method of making a vitrimeric polymer network, comprising: obtaining multifunctional triketone dimers; obtaining a multifunctional imine compound, with imine groups blocking amine groups; mixing the multifunctional triketone dimers with the multifunctional imine compound, thereby forming a polymer precursor mixture; applying the polymer precursor mixture onto a substrate; and allowing the multifunctional imine compound to undergo hydrolysis with water, unblocking the amine functional groups and generating a multifunctional amine compound. The multifunctional amine compound reacts with the multifunctional triketone dimers to form a vitrimeric polymer network.

Abstract: Tethered Unmanned Aircraft Antenna utilizing a Vertical Take Off and Landing (VTOL) Unmanned Aerial System (UAS) which may be provided by quadcopter drone (for example) constrained by a tether connected at one end to a maritime or land-based platform, the tether also being used as a RF antenna. The tether is capable of transmitting DC power to the UAS or drone at a desired antenna height and simultaneously supports RF transmission power with the help of a DC power isolation circuit. The tether is desirously lightweight and corona resistant.

Abstract: A RF antenna comprises a quartz resonator having electrodes disposed thereon with a magnetostrictive film disposed on the quartz resonator either on, partially under or adjacent at least one of the electrodes.

Abstract: A HEMT comprising a channel layer of a first III-Nitride semiconductor material, grown on a N-polar surface of a back barrier layer of a second III-Nitride semiconductor material; the second III-Nitride semiconductor material having a larger band gap than the first III-Nitride semiconductor material, such that a positively charged polarization interface and two-dimensional electron gas is obtained in the channel layer; a passivation, capping layer, of said first III-Nitride semiconductor material, formed on top of and in contact with a first portion of a N-polar surface of said channel layer; a gate trench traversing the passivation, capping layer, and ending at said N-polar surface of said channel layer; and a gate conductor filling said gate trench.

Abstract: An ultraconductor includes: a base substrate; a carbon nanotube layer on the base substrate, the carbon nanotube layer including a plurality of carbon nanotubes; and an insulating layer on the carbon nanotube layer, wherein the plurality of carbon nanotubes are substantially all aligned along a longitudinal axis of the base substrate. A method of manufacturing the ultraconductor includes: preparing a base substrate; depositing a plurality of carbon nanotubes on the base substrate to form a carbon nanotube layer; depositing an insulating layer on the carbon nanotube layer, wherein the plurality of carbon nanotubes are substantially all aligned along a longitudinal axis of the base substrate.

Abstract: Described is a method for improved performance of agent-based machine learning. The method includes training a reinforcement learning (RL) agent on an image processing task. A dataset of states and corresponding actions is then extracted from the RL agent. A measure of attention is applied to an input space of the RL agent. During action selection by the RL agent, image patches of the input space are extracted based on the applied measure of attention. Portions of a set of inputs are clustered based on similarity to the image patches, generating a set of clusters having cluster centers. Non-semantic concept labels are provided as distances to the cluster centers for each state in the dataset.

Abstract: Described is a system for performing a simulated vehicle control task based on adversarial decision analysis. Empirical game theoretic analyses are performed between an evolving and an adversary population of neural network strategies. Each empirical game theoretic analysis includes using a neuroevolution procedure to perform a fitness-based selection of a strategy in the evolving population that out-performs the adversary population. Using an empirical game theory procedure, the neuroevolution procedure is iteratively run and the selected strategy is added to the adversary population with each iteration, resulting in monotonic strategy improvement with each iteration. Following the empirical game theoretic analyses, a final strategy is selected for the evolving population and the adversary population using a tournament selection procedure. The final strategy is used to train a neural network which is used to perform a simulated vehicle control task.

Abstract: An electronic assembly, comprising a carrier wafer of a first material, having a top wafer surface and a bottom wafer surface; said carrier wafer comprising a through-wafer cavity having walls that join said top wafer surface to said bottom wafer surface; and an insulator of a second material, different from the first material, having insulator top and bottom surfaces, joined by insulator side surfaces, and having a conducting via that passes through said insulator between said insulator top surface and said insulator bottom surface; wherein the insulator is held in said through-wafer cavity by direct contact of the insulator side surfaces with an attachment metal that fills said through-wafer cavity.

Abstract: An exemplary receive antenna having a conductive surface. The conductive surface includes an aperture configured to operate as a slot antenna, and one or more amplifiers or buffer amplifiers is electrically connected across the aperture. At least one feed is connected between the one or more amplifiers and the aperture. An input impedance ZB of each of the one or more amplifiers at the at least one feed location is lower than 0.5× an impedance of the aperture ZA at a first resonance frequency.

Abstract: Described is a system for optimizing controllers for micro-air vehicles. The system identifies binary rules that lead to a desired behavior of a micro-air vehicle. The binary rules are identified by sampling rule-sets from a probability distribution over a search space. A fitness value of each rule-set for the desired behavior is determined, and top-performing rule-sets are selected. The top-performing rule-sets are used to update the probability distribution over the search space until a convergence criterion is met, resulting in a fittest rule-set. A control signal based on the identified binary rules is transmitted to one or more actuators of the micro-air vehicle.

Abstract: Some variations provide an atomic instrument configured with an optically transparent and electrochemically cleanable window, comprising: a transparent first electrode; a second electrode with an atom reservoir for first metal ions; an ion conductor interposed between the first electrode and a second electrode, wherein the ion conductor is capable of transporting second metal ions, wherein the ion conductor is in contact with the first electrode and with the second electrode, and wherein the ion conductor is optically transparent; and a transparent window support in contact with the ion conductor, wherein the electrochemically cleanable window is optically transparent, wherein the transparent window support, the ion conductor, and the first electrode collectively form a transparent and electrochemically cleanable window.

Abstract: An apparatus and related method are disclosed for compensation of an antenna and/or an antenna array located at a surface that experiences environmental conditions. The apparatus can include: an embedded compensation and/or calibration structure configured to be interrogated by an electromagnetic wave, to dynamically compensate for surface erosion, thermal expansion, and/or dielectric constant changes of a surface scattering antenna; and a processor configured to: receive measurements of the compensation and/or calibration structure to determine beam pointing for dynamically varying surface conditions and perform sensing and/or seeking observation.

Abstract: An atomic-beam source device is configured to provide a collimated beam of atoms, wherein solid-state electrochemistry is employed to recirculate atoms that are caught on collimation channel walls. The use of solid-state electrochemistry to recirculate atoms enables a chip-scale, dark-wall, high-quality collimated beam source that does not clog over time. Some variations provide an atomic-beam source device comprising: a first electrode; a second electrode that is electrically isolated from the first electrode; a first ion conductor interposed between the first electrode and the second electrode, wherein the first ion conductor is capable of transporting metal ions, and wherein the first ion conductor is in contact with the first electrode and with the second electrode; and one or more collimation channels disposed outwardly from the first ion conductor. Methods of using the atomic-beam source device are disclosed, including methods to recirculate and reuse metal atoms adsorbed on collimation channel walls.