Abstract: A manufacturing process is provided to increase fracture toughness and reduce brittleness for a semi-crystalline polymer material. A material such as poly(vinylidene fluoride-trifluorethylene) or p(VDF-TrFE) is placed in an inert oxygen-free atmosphere and heated to a temperature that is greater than room temperature but below the melting temperature of the material. The material is then irradiated with beta particles until a desired level of fracture toughness is achieved where fracture toughness is a function of the radiation dose.

Abstract: A neural director is provided which is a neural network constructed with weights that are determined a priori. The neural director receives an input vector X comprising “I” input components “Xi” and generates in response an output vector Y comprising “J” output components. The neural director has an input processing node layer which receives the input vector X and an output processing node layer which generates the output vector Y. The connections between the input and output processing node layers are a unique weighting set w(i,j) that contains an internal representation of a uniform spatial distribution of “J” unit vectors throughout a unit sphere of “I” dimensions. Thus the cosine value between any two adjacent unit vectors is a constant everywhere in the unit sphere.

Abstract: The apparatus and method of the present invention utilize hysteresis to provide accurate and stable track quality indicator (TQI) data. In accordance with the present invention, each TQI state has two corresponding thresholds. Specifically, each TQI state has an initial threshold that must be surpassed by an initial or first summed log likelihood ratio (SLLR0) before a change in current TQI state is made to a higher TQI state, and a lower threshold below which a second SLLR1 must decrease in order to effect a change in current TQI state to a lower TQI state. Thus, SLLR0 is used to determine if the tracker quality indicates a low SNR track, an uncertain track or a lost track, and SLLR1 is used to determine if the tracker quality indicates a strong track. In accordance with the present invention, the values of SLLR0 and SLLR1 and the absolute value of the smoothed tracker residual are used to generate a current TQI value.

Abstract: A system for bearinqs-only contact state estimation in response to target bearing and ownship speed and course information provided for a plurality of observation legs at successive points in time, includes a plurality of neural networks and a data fusion circuit. Each of the neural networks generates range-normalized parameter estimate information for one of the observation legs in response to target bearing and ownship speed and course information for an associated one of the observation legs, provided thereto at each point in time and information generated for the previous point in time. The data fusion system receives the range-normalized parameter estimate information from the neural networks and generates the contact state estimate in response thereto.

Abstract: A method for estimating the real and imaginary Young's modulus, shear modulus and Poisson's ratio of a specimen at an excitation frequency. The specimen is first joined to a reciprocating test apparatus at one end with a mass positioned at the other end. The test apparatus reciprocates at the excitation frequency and accelerations are recorded at each end of the specimen. The Young's modulus is calculated from the recorded accelerations. The specimen is then joined to a reciprocating rotational test apparatus at one end with a rotational inertial mass positioned at the other end. Accelerations are recorded upon subjecting the specimen to rotational reciprocations at the excitation frequency. The shear modulus is calculated from these accelerations. Poisson's ration can be calculated from the Young's modulus and the shear modulus at the excitation frequency. All of the calculations may be performed giving both real and imaginary values.

Abstract: A method for coupling fiber optic elements includes providing a hollow wax housing. A first fiber optic element is inserted in a first direction into the housing to position a free end thereof in the housing. A second fiber optic element is inserted into the housing from an opposite direction to position a free end of the second fiber optic element in the housing confronting the first fiber optic element free end. The housing is filled with optical grade epoxy resin which is permitted to cure, thereby to effect physical and optical connection between the first and second fiber optic elements. The free ends are in close proximity, or in the case of coupling from one strand to many, in enough of a spaced relation to cause needed light diffusion.

Abstract: A system and method is disclosed for retrieving an untethered submarine tube-retrievable UUV in which the untethered submarine tube-retrievable UUV may be retrieved through the torpedo tube of a submarine. The untethered submarine tube-retrievable UUV has a capture cable extending therefrom with a transducer to produce a homing signal. A tethered homing signal seeking UUV is guided toward the homing signal. Capture arms on the tethered homing signal seeking UUV engage the capture cable and guide the capture cable to one of several cable snagging eye-members. The winching cable is then winched back into the torpedo tube thereby drawing the untethered submarine tube-retrievable UUV into the torpedo tube.

Abstract: A signal processing system provides and processes a digital signal, converted from to an analog signal, which includes a noise component and possibly also an information component comprising small samples representing four mutually orthogonal items of measurement information representable as a sample point in a symbolic Cartesian four-dimensional spatial reference system. An information processing sub-system receives said digital signal and processes it to extract the information component. A noise likelihood determination sub-system receives the digital signal and generates a random noise assessment of whether or not the digital signal comprises solely random noise, and if not, generates an assessment of degree-of-randomness. The information processing system is illustrated as combat control equipment for undersea warfare, which utilizes a sonar signal produced by a towed linear transducer array, and whose mode operation employs four mutually orthogonal items of measurement information.

Abstract: A missile launch assembly for underwater vehicles includes a launch tank having mounted therein an expandable elastomeric disc and a turbine, a water inlet conduit, an impulse tank interconnecting the water inlet conduit and a missile launch tube, and a pump inducer mounted in the water inlet conduit and drivable by the turbine. Movement of the disc from an expanded to a non-expanded condition causes water in the launch tank to drive the turbine to drive the pump inducer to pump water from the water inlet conduit to the impulse tank and thence to the launch tube to effect launch of a missile therein.

Abstract: A neural sensor is provided which receives raw input data defining a pattern, such as image or sound data, and generates a classification identifier for the pattern. The neural sensor has a pattern array former which organizes the raw input data into the proper array format. A first order processing section receives the pattern array and generates a first order feature vector illustrative of first order features of the input data. A second order processing section also receives the pattern array and generates at least one second order feature vector illustrative of gradients in the input data. A vector fusion section receives the feature vectors from the first and second order processing sections and generates a single fused feature vector which is provided to a pattern classifier network. The pattern classifier network, in turn, generates a pattern classification for the input data.

Abstract: A system for digitally demodulating optical hydrophone signals is provided. The system includes an optical hydrophone connected to an analog-to-digital converter and further connected to a digital signal processor. Within the digital signal processor, a demodulator is calibrated by a preferred automatic calibration circuit such that mixer frequencies are coherently mixed with the incoming acoustic signals received by the hydrophone. The automatic calibration circuit preferably determines an extreme case of phase offset by following a programmable routine including a series of tests. After the extreme case is detected, the precise phase calibration is known and provided to the demodulator mixer tables. The automatic calibration circuit can be utilized for automatic calibrations of multisensor systems containing large numbers of hydrophones.

Abstract: A method is disclosed for protecting optical fibers embedded in the armor of a tow cable. The method includes the steps of winding a resin-impregnated fiber onto a stainless steel tube, and curing the resin to form a hard protective filament shell around the stainless steel tube. The fiber is a continuous fiber and the step of impregnating is either in combination with the step of winding or prior to the step of winding. The fiber used is any one of a carbon fiber, a Kevlar™ fiber, a boron fiber or the like. The winding is either applied during formation of the steel tube or subsequent to formation of the steel tube. The method further comprises the step of winding galvanized steel armor wires of a predetermined diameter around the tow cable core to form the tow cable and helixing the protected tube amongst the galvanized steel armor wires.

Abstract: A system and method are provided for an adaptive filter that is especially useful for sonar signal processing. The beam outputs of a conventional beamformer are provided as inputs to adaptive notch filters in accord with the present invention. The outputs of the plurality of adaptive notch filters are applied to a standard cross correlation process. In each of the adaptive notch filters, the beam outputs are split into two paths and in one path are applied directly to a signal combiner. In the second path, the beam outputs are delayed. The delayed beam outputs are applied to an adaptive finite impulse response filter, the output of which is an estimate of the narrowband interference contained within the beam output. The narrowband interference is then suppressed in the signal combiner prior to application to the standard cross correlation process.

Abstract: An isolated mechanical fastening system, which includes an exterior first section having a first transverse bore. The system also includes an exterior second section having a second transverse bore, wherein the second transverse bore is aligned with the first transverse bore. There is also an interior third section having a third transverse aperture. This third section is interposed between the first section and the second section and the third transverse bore is aligned with the first and second transverse bores. A fastener is positioned in the first, second and third transverse bore and is fixed to the first section. A polymeric material is positioned in the third section between the fastener and the peripheral wall of the third section.

Abstract: An apparatus and method for identifying the timing of the onset of and duration of an event characteristic of sleep breathing disorder while a patient is awake. Chaotic processing techniques analyze data concerning a cardio-respiratory function, such as nasal air flow. Excursions of the resulting signal beyond a threshold provide markers for delivering the average repetition rate for such events that is useful in the diagnosis of obstructed sleep apnea and other respiratory dysfunctions.

Abstract: A method is provided to process system test data to determine certification parameters of the system based on the test data. For a torpedo launch system, the velocity data is generated by a Pressure/Velocity/Displacement housing interfaced with a computer based data acquisition system and known launch system and test parameters, such as sample rate, muzzle exit length, time of acquisition, decimation factor and low pass cutoff frequency are provided as inputs. The method forces assigns a value of zero to any data less than a predetermined threshold in order to eliminate non-zero levels contributed by ambient noise. The method then passes the data through a filter chosen to agree with hand fit smoothing methods, so as to obtain a smoothed velocity profile. The smoothed data is processed to obtain and display an acceleration profile and a displacement profile, as well as data points for peak acceleration, time at peak, acceleration pulse width, muzzle exit velocity and time at exit.

Abstract: The present invention provides an outboard test facility that is operable for testing a ship's direction finding antenna system in all directions as the ship circles while receiving test signals from the outboard test facility. The test facility provides a computer control operable for monitoring and storing signal power produced by any selected patch interconnections between a plurality of antennas, a plurality of radio frequency amplifiers and a plurality of signal generators at the outboard test facility. The computer control permits a single operator to monitor a signal analyzer to determine the optimum signal power for each of a list of signal frequencies to be broadcast to the ship based on the selected patch interconnection.

Abstract: The calibration circuit is used with a differential input, monolithic integrated circuit preamplifier in a sensor system. The calibration circuit tests the integrity of the sensor, the preamplifier, and the wiring in the sensor system. The calibration circuit includes first and second calibration capacitors having different capacitances connected to the preamplifier input leads. A calibration signal source is connected between the capacitors. The capacitors are preferably implemented on the same integrated circuit as the preamplifier. In operation, a calibration signal of known amplitude is applied to the calibration circuit and the level at the preamplifier output is determined. The level at the preamplifier output indicates certain conditions relating to the integrity of the sensor and its wiring, for example, an open circuit condition or a short circuit condition.

Abstract: An apparatus and method are used to determine equivalent individual phase voltages and phase currents from an alternating delta power source and load configuration. A delta-wye input transformer and a wye-delta output transformer are interconnected between the delta power source and the delta power load. Each phase of the delta power source is effectively connected across a corresponding wye configured coil. The delta-wye input transformer and the wye-delta output transformer are electrically connected to each other in a manner thereby providing three conductors through which the individual phase currents through the wye coils may be directly measured. The phase voltages are preferably measured across the wye coils of either the input transformer or the output transformer not intermixed.

Abstract: A method is provided to capture and process wire guidance fire control command tones. The method is implemented on a computer, which monitors and displays the wire guidance command tones in real time, showing the tone or signal over time. A user controls the beginning and ending of the capture period. The captured data is stored within the computer. Once data capturing has ended, the full record of the captured data is displayed. The display includes active cursors denoting the start and stop of the recorded event. The cursors may be positioned independently along the data display so as to bracket a tone event of interest. Once the cursors are positioned, the method updates the display to show only the bracketed event. The time duration of the event is also shown as well as a computed frequency for the event. The user may then continue refining the positions of the cursors to accurately identify the event of interest.