Abstract: This document discusses, among other things, apparatus and methods for providing persistent biometric authentication for a computer system. In an example, a method can include collecting behavioral interaction information associated with a user account on the computer system, comparing the behavioral interaction information with a behavioral model associated with the user account; and adjusting an authentication confidence metric based on the comparison.

Abstract: A man-portable non-lethal pressure shield provides both a physical as well as pressure shield. The pressure shield addresses the concerns of military, police and human rights organizations and international law as regards effectiveness, efficiency and safety and efficiency. A folded acoustic horn is incorporated into the physical shell of the shield. The horn couples acoustic pulses from a sonic pulse generator to an acoustic aperture to output a pulsed pressure beam that approximates a plane wave to produce a pressure barrier. The operator may specify a desired effect on its human target that is maintained as range-to-target changes or a desired effect at a specified perimeter range. The shields may be networked to facilitate coordinated action among multiple pressure shields as a force multiplier or to provide a more sophisticated pressure barrier.

Abstract: An acoustic weapon comprises a sonic pulse generator configured to generate discrete sonic pulses at a repetition rate. A sensor is configured to measure a range-to-target. A controller is configured to control the sonic pulse generator to generate a single shot including a burst of multiple pulses at a fixed repetition rate, to adjust the fixed repetition rate to shift the frequency content of the burst in accordance with a target coupling efficiency towards improving energy transfer to the target and to adjust the peak pressure of the burst in accordance with the range-to-target towards applying a specified peak pressure to the target. The controller may incorporate the target coupling efficiency as well as other parameters such as target apparent area and beam width when adjusting the weapon peak pressure. A pulse detonation engine (PDE) or pulse manifold (PM) may be modified and controlled to provide the large discrete peak pressures required at a periodic repetition rate.

Abstract: A man-portable non-lethal pressure shield provides both a physical as well as pressure shield. The pressure shield addresses the concerns of military, police and human rights organizations and international law as regards effectiveness, efficiency and safety and efficiency. A folded acoustic horn is incorporated into the physical shell of the shield. The horn couples acoustic pulses from a sonic pulse generator to an acoustic aperture to output a pulsed pressure beam that approximates a plane wave to produce a pressure barrier. The operator may specify a desired effect on its human target that is maintained as range-to-target changes or a desired effect at a specified perimeter range. The shields may be networked to facilitate coordinated action among multiple pressure shields as a force multiplier or to provide a more sophisticated pressure barrier.