Abstract: A multiaxial high cycle fatigue test system for testing bending, torsion, and tension of a test unit, comprises servo-hydraulic components, including a hydraulic service manifold, two small high frequency actuators along a first axis, and one large main actuator along a second axis The large main actuator is used to apply a radial centrifugal force, and the two small actuators are used to apply vibratory loading; the two small side actuators being offset independently of each other, to enable the machine to apply both bending loads and torque to the test unit. The test unit is subjected to torsion loading when the traverse actuators move in phase, that is when both actuators move either in or out at the same time. The test unit is subjected to bending loading when the actuators move out-of-phase, that is one actuator moves in when the other moves out or vice-versa.

Abstract: The system according to the invention uses cutting edge technologies such as Uncooled Staring Focal Plane detector Array, Hot Pressed Polycrystal Objective Lens, Helmet Mounted Display Using Transparent Image Combiner, and Neural Network Image Colorization and Recognition to dramatically enhance the system performance and reduce the weight and cost. The helmet mounted infrared imaging system can: Detect and recognize flames, humans and other objects, Reduce the weight of the helmet components (including camera head and combiner) to less than 0.5 pounds, View simultaneously visible and invisible surroundings without hindering operations. Operate the imaging system hands-off; and Transmit the imaging data to and receive the map from a remote sight. Alternative Embodiment In an alternative embodiment, the infrared camera is mounted centered in front of the display.

Abstract: A passive/active infrared imaging system apparatus for mounting on a head/helmet includes a passive infrared camera Head Pack having a removable narrow band filter cover, an objective lens, a beam splitter, an uncooled focal plane array (UFPA) package, an interface board, and a display unit such a liquid crystal display (LCD), with forward/back, up/down, and tilt adjustment functions fitting any mask, mounted in the front of said head/helmet for converting infrared light images into electronic signals. An electronic unit coupled between the UFPA of the infrared camera and the display unit, includes a controller for processing video signals from the infrared camera and supplying them to the display unit. The electronic circuit includes a wireless video & audio transceiver, a piezoelectric microphone, a voice controller, and a neural network pattern recognition chip.

Abstract: The radio transmission circuit comprises 16 antenna elements in a broadside array. A carrier wave is routed to the 16 elements and the phase to each element is adjusted to direct the transmitted wavefront toward a selected receive point. Prior to transmission, however, the carrier to each element is independently modulated by a two-state (0/&pgr;) phase shifter. Each of the 16 carriers is modulated with the first 16 orthogonal Walsh waveforms (a digital counterpart of the Fourier Transform). The output power levels at all antennas are equal, only the phase of the RF carriers change. Depending upon the sign conditions (inverted or noninverted) for the various 16 modulation waveforms, a pulse position modulation (PPM) signal is transmitted in which the pulse can occupy one of 16 time positions.

Abstract: Two new homing guidance laws, designated as proportional Guidance (PROGUIDE) and Augmented Proportional Guidance (Augmented PROGUIDE), have been developed for use against non-maneuvering and maneuvering targets, respectively. These guidance laws are the solutions of linear-quadratic regulator control problems and minimize deviations from the collision triangle over the entire period of homing flight, thereby indirectly minimizing miss distance. In contrast to proportional navigation (PRONAV), these algorithms command the achievement of angular acceleration instead of linear acceleration and there is a significant advantage in doing so.

Abstract: The Pulsed Laser Deposition (PLD) growth process uses a target of a given material and a substrate located within a vacuum chamber. A UV laser beam scans the target to produce a plasma which coats the substrate. Sensors for the vacuum chamber, with a data acquisition channel, are coupled to a process control computer. The bus is also coupled to a mirror gimbal control for directing the laser beam on the target. The process control provides for initializing a PLD instrumentation system, opening a data file, controlling deposit of a PLD film, determining when a desired deposition time or thickness is completed and then shutting down the laser, and closing the data file.

Abstract: A new algorithm for reinforcement learning, advantage updating, is proposed. Advantage updating is a direct learning technique; it does not require a model to be given or learned. It is incremental, requiring only a constant amount of calculation per time step, independent of the number of possible actions, possible outcomes from a given action, or number of states. Analysis and simulation indicate that advantage updating is applicable to reinforcement learning systems working in continuous time (or discrete time with small time steps) for which Q-learning is not applicable. Simulation results are presented indicating that for a simple linear quadratic regulator (LQR) problem with no noise and large time steps, advantage updating learns slightly faster than Q-learning. When there is noise or small time steps, advantage updating learns more quickly than Q-learning by a factor of more than 100,000. Convergence properties and implementation issues are discussed.

Abstract: The incorporation of an aluminum arsenide (AlAs) buffer layer in a gallium arsenide (GaAs) field effect transistor (FET) structure is found to improve the overall device performance, particularly in the high temperature operating regime. Similar characteristics may be obtained from devices fabricated with an Al.sub.x Ga.sub.1-x As 0.2.ltoreq.x.ltoreq.1 barrier layer. At temperatures greater than 250.degree. C., the semi-insulating gallium arsenide substrate begins to conduct significant amounts of current. The highly resistive AlAs buffer layer limits this increased conduction, thus permitting device operation at temperatures where parasitic leakage currents would impede or prevent device operation. Devices fabricated with AlAs buffer layers exhibited lower drain parasitic leakage currents and showed improved output conductance characteristics at 350.degree. C. ambient temperature.

Abstract: To greatly increase the sensitivity of a Heterodyne Ladar System, the receiver incorporates an optical preamplifier to amplify the ladar return signal prior to detection. This results in an increase in return signal power on the order of 25 dB. Spontaneous emission noise added by the fiber amplifier counters this gain in a normal scheme. The proposed receiver, however, incorporates a Polarization Optical Mixer to perform balanced mixing, thus rejecting added spontaneous emission beat noise terms and resulting in a large increase in system sensitivity.

Abstract: A microphone array speech enhancement algorithm based on analysis/synthesis filtering that allows for variable signal distortion. The algorithm is used to suppress additive noise and interference. The processing structure consists of delaying the received signals so that the desired signal components add coherently, filtering each of the delayed signals through an analysis filter bank, summing the corresponding channel outputs from the sensors, applying a gain function to the channel outputs, and combining the weighted channel outputs using a synthesis filter. The structure uses two different gain functions, both of which are based on cross correlations of the channel signals from the two sensors. The first gain yields the GEQ-I array, which performs best for the case of a desired speech signal corrupted by uncorrelated white background noise. The second gain yields the GEQ-II array, which performs best for the case where there are more signals than microphones.

Abstract: The encode and decode subsystems use a continuously variable slope delta-modulation (CVSD) approach, with either parallel or serial data transfers. To allow for synchronization with a stable data transfer, the entire subsystem uses the main acquisition systems bit rate clock (BRC) as a basis. All other clocks required are simply divided down versions of the BRC and a request pulse from the main system to transfer the data. The delta-modulator is clocked at a rate commensurate with the word placement in the minor frame of the data acquisition cycle; the NRZ-L bits are clocked into serial-to-parallel registers, then latched into the parallel discrete interface (PDI) unit of the main data system. For a serial feed, a similar situation is possible by clocking the data off the circuit board into a serial discrete interface (SDI) unit. The request pulse that activates, the transfer is synchronized with the BRC to ensure a stable transfer. The decoder uses the same CVSD integrated circuit to decode the digital data.

Abstract: A double diamond configuration of phase shift circuits are coupled via circulators, amplifiers, power dividers, and power combiners. The circuit arrangement serves to amplify signals in either direction while accurately maintaining relative phase shift. There is a 180 degree phase shift between components back to the originating transmission line, to this cancel them. The circuit may be used between microwave transmission lines, such as waveguides.

Abstract: Boundary scan testing of devices such as printed circuit boards and multi chip modules, when the needed circuits have not been provided on IC chips by the manufacturer, is accomplished with a diagnostic and testing integrated circuit that performs a boundary scan external to available integrated circuitry with the addition of programmable input/output parameters. Programmable boundary scan functions include input or output functions, enable or disable cells, and shift register orders. The boundary scan function programming will allow each boundary scan cell to be defined as an input/output boundary scan cell. The enable cell programmability would provide the capability of shutting down unused cells in a given application to program proper data flow and to conserve power.

Abstract: A hierarchical control PLD system controls deposition processes by feedback means, for industrial production of tribological thin films. PLD process system identification, intelligent feedback control architecture, and implementation for ultraviolet pulsed laser deposition processes are provided. This system has three levels of feedback control. The first level of feedback control improves the precision and tracking of sub process variables by linear observer based compensator control. The Mo I plume species density per laser pulse and bulk substrate thickness by the quartz crystal micro balance provide real time sub process data to the observer. The observer based compensator then directly calculates laser energy density per pulse and pulse repetition rate based on the current values predicted by the linear model. The second level consists of a dynamical system design algorithm and nonlinear process map.

Abstract: This invention involves a method of providing suitable electrical isolation for small metal particles (such as iron) from each other, agglomerating these particles into a larger size, and overcoating the agglomerates to provide environmental protection. A product of this type has attractive electromagnetic absorbing properties at ultra high frequencies even when used in a high temperature environment that would have oxidized uncoated iron particles with resultant deterioration of its absorbing properties.

Abstract: An instantaneous frequency measurement receiver (IFM) is used at each output of a digital channelized receiver. A Fast Frequency Transform (FFT) is used to form an instantaneous frequency measurement (IFM) receiver at every frequency component. These IFM receivers can perform frequency coding and produce fine frequency measurement.

Abstract: A solution to the AOA problem is provided, receiving the data via a plurality of antennas, which uses a switching network to couple the antennas to a single receiver and a single analog-to-digital converter to digitize the incoming signal. It is possible to solve the problem where there might be multiple signals present. In the receiver, the incident radiation is mixed with a local oscillator signal and down converted to an intermediate frequency (IF). This IF signal is discretely sampled in the analog-to-digital converter, and further processing is done using digital techniques. The incoming signal has to be phase compared to obtain the angle of arrival. Different delay times are used to receive the digital data from the different antennas at the same sampling times, with the data aligned according to the time axis. The frequency of the incoming signals can then be detected by performing a Fast Fourier Transform (FFT) on the data from one antenna with respect to time.

Abstract: In the design of the process to machine discrete mechanical parts, the sequence of removing material is arrived at to ensure that the resulting part is of the correct geometry and finish, and the process is safe, feasible and accomplished in minimum time. For complex parts, an experienced machinist makes use of inductive methods to relate similar part material, geometries together with interdependencies and their associated machining sequences which have produced quality parts in the past with minimum time expended, or deductive methods to generate a sequence by relating feature attributes (relative size and position) and relations (intersections and common tooling). Of interest is the interaction between the two methods because their coupling enables a self-improving design system to be realized. A feature-based solid modelling software environment provides the elements of a symbolic language for describing a discrete mechanical part in terms of its product and process design.

Abstract: This system compares the phases from Fast Frequency Transform (FFT) outputs to obtain angle of arrival (AOA) information.

Abstract: Two new adaptive homing guidance laws are developed which are variants of Augmented Proportional Navigation (PRONAV). The first guidance law commands flight path angle rate and is referred to as adaptive matched augmented PRONAV (AMAAP). The second guidance law commands linear acceleration and is referred to as adaptive matched augmented linear PRONAV (AMALP). The major attributes of these guidance laws are (1) they are the solutions of a linear quadratic control problem, (2) they do not require an estimate of time-to-go (tgo), (3) they are matched to a nonlinear model of the target's motion, (4) they adapt in real time to provide optimal guidance over each small segment of the intercept trajectory, and (5) they optimally account for missile deceleration.