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 system and method for determining a sound speed profile of a water column. A free falling sound source is deployed in the water at a known location and time. The sound source transmits acoustic pulses omnidirectionally therefrom at predetermined times after deployment. An acoustic receiver located at a known location detects each acoustic pulse. The time differential between each predetermined time and a time of arrival for each subsequent acoustic pulse is determined. Speed of sound for each portion of the water column is then determined as a function of the time differential, the known locations of sound source deployment and the acoustic receiver, and the known rate of descent of the sound source. The sound source can be constructed from a hydrodynamic body housing a power source, timing electronics, and spark gap electrodes. A bubble, generated by the spark gap electrodes, implodes to create the acoustic pulse.

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: A free-floating altitude stabilized system is provided. Independently energizable wire coils are linearly aligned with one another in a vertical direction on a buoyant body. An induced magnetic field is generated by any of the wire coils that are energized. A float housing a magnet is coupled to the body in such a way that it is capable of independent movement relative thereto. A control system energizes a selected one or more of the wire coils in such a way the magnet's magnetic field and wire coil's induced magnetic field react with one another to generate movement of the float vertically in a direction that is the same as a vertical component of wave motion.

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: The detachable shock-absorbing ram-plate is used in a projectile launching system to mitigate launching impact forces and to prevent ram-plate re-strike during launch. The detachable shock-absorbing ram-plate is detachably coupled to the projectile using break-away fasteners that allow the ram-plate to be attached to the projectile during launch and detached from the projectile at the end of the launch. One embodiment of the detachable shock-absorbing ram-plate is a single impact, viscous fluid ram-plate including a cylinder, a perforated piston, and a viscous fluid disposed between the cylinder and the perforated piston. Upon receiving a high initial launch impact force, the piston compresses causing the viscous fluid to be forced through the perforated piston, thereby absorbing the shock of the initial launching impact force. Another embodiment of the detachable shock-absorbing ram-plate is a gas spring ram-plate having a cylinder and piston that compresses a gas to absorb shock caused by launching forces.

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: The present invention relates to a sensor interrogation system which comprises an optical fiber, at least one sensor containing first and second fiber lasers attached to the optical fiber with the first fiber laser being located spectrally at a first wavelength and the second fiber laser being located spectrally at a second wavelength different from the first wavelength, a pump laser for causing light to travel down the optical fiber so as to cause each of the fiber lasers to lase at its distinct wavelength and generate a distinct laser signal representative of the distinct wavelength, at least one filter for receiving the laser signals generated by the first and second lasers and for transmitting the laser signals from the first and second lasers within a wavelength band, and first and second scanning Fabry-Perot spectrum analyzers for receiving the laser signals for determining the wavelength difference between said fiber lasers.

Abstract: A termination assembly for disposal between a marine tow cable and an acoustic receiver array includes a cable sleeve having a grip portion adapted to grip a cable outer jacket, and a collar portion for disposition on a strength member portion of the cable. The termination assembly further includes a coupling comprising an inner sleeve for mounting on a coax portion of the cable, an electrical connector for abutting a distal end of the coax portion, a coupling body interconnecting the inner sleeve and the electrical connector, the coupling body having a cylindrically-shaped wall disposed around the electrical connector to define therebetween an annular recess for receiving a connector of the acoustic receiver array, a coupling nut mounted on the coupling body and engageable with the acoustic receiver array connector to lock the acoustic receiver array connector onto the electrical connector, and an outer sleeve fixed to the coupling body.

Abstract: An ultrasonic sparse imaging array includes a substrate of an acoustically absorptive material, through which extend a multiplicity of holes. Adhesive sheets, having selectively conductive regions, are fixed to a first side of the substrate, and are each disposed over a first end of one of the holes. Plano-convex shaped transducer elements, having a wide acoustic field of view, are disposed on each of the sheets, each of the sheets serving as a positive electrode and providing a mechanical and electrical connection between the substrate and a multiplicity of transducer elements. Plating is fixed to the first side of the substrate and covers each of the transducer elements and comprises a negative electrode. A conductive epoxy fills each of the holes and a power source is in electrical communication with the negative electrode.

Abstract: A dynamic memory processor for time variant pattern recognition and an input data dimensionality reduction is provided having a multi-layer harmonic neural network and a classifier network. The multi-layer harmonic neural network receives a fused feature vector of the pattern to be recognized from a neural sensor and generates output vectors which aid in discrimination between similar patterns. The fused feature vector and each output vector are separately provided to corresponding positional king of the mountain (PKOM) circuits within the classifier network. Each PKOM circuit generates a positional output vector with only one element having a value corresponding to one, the element corresponding to the element of its input vector having the highest contribution. The positional output vectors are mapped into a multidimensional memory space and read by a recognition vector array which generates a plurality of recognition vectors.

Abstract: An apparatus and method for determining linear and angular velocity of a moving body. A magnet is attached or fixed to the body, the velocity of which is to be determined. The apparatus comprises a sensor comprising a core of magnetic material and a coil wound about the core. The movement of the body and magnet relative to the core effects a time-varying magnetic field between the magnet and the core thereby producing Barkhausen effect time-varying voltage signals in the coil. The apparatus further comprises a system for detecting and processing the time-varying voltage signals so as to effect a transformation of the signals into data defining the velocity of the moving body.

Abstract: A submarine countermeasure vehicle includes an elongated body for supporting a countermeasure device, and a propulsion assembly mounted on an after end of the body. The propulsion assembly includes a rotatable propeller hub, propeller blades mounted on the hub and moveable between a first position wherein the blades extend substantially radially outwardly from the hub, and a second position wherein the blades extend generally axially of the hub. A spring is mounted on each of the blades and in the hub, the spring biasing the blades toward the first position, but of sufficient flexibility to permit the blades to move to the second position upon launch of the vehicle from an underwater launch tube.

Abstract: A method to improve communication system performance using an adaptive modem that estimates the communication channel scattering function to select one of several modulation schemes. The scattering function is estimated from the channel's frequency (doppler) and time (multipath) spreading effects on a probe signal. The probe signal is transmitted from a first modem to a second modem. The second modem processes the channel measurements and transmits the channel spreading factors to the first modem. Based upon the channel scattering function estimate, channel characteristic data, propagation models, strategic information, and modem position estimates, the first modem selects one of several modulation schemes. Subsequent data transmissions from the first modem to the second modem contain a modulation mode identifier. The second modem uses the modulation mode identifier to select the correct demodulation scheme.

Abstract: An underwater self adjusting displacement device includes a sealed housing having an exterior wall and an inner component area, the exterior wall having an opening formed therein. A sealing plug is slidably seated in the opening of the exterior wall, and an actuator mechanism selectively adjusts the sealing plug within the opening, thereby adjusting a total displacement of the sealed housing. The displacement device is incorporated into any substantially neutrally buoyant underwater deployable device such as an acoustic countermeasure device or an oceanographic sensor device. Further, the deployable devices may be deployed individually or as a field due. The displacement device requires less weight and weight within an overall deployed device, enabling large deployments and performance enhancements.

Abstract: The invention is directed to a high-speed, puncture proof tire including a tire casing having a tread portion and a pair of side wall portions and a plurality of small diameter pressurized tubes disposed within the tire casing. Each pressurized tube has an elongate body fabricated from film material that is sealed crosswise along the length of the body to define at least two compartments that contain gas-under pressure. The tubes can be oriented radially or circumferentially within the annular space of the tire casing. In another embodiment of the tire, at least one panel of film material resistant to shear forces is disposed within the annular space of the tire casing. The panel is sealed lengthwise thereof to define a plurality of small diameter pressurized tubes. Each pressurized tube is sealed crosswise along the length of the tube to define at least two compartments that contain gas under pressure.

Abstract: A warning system for identifying a track misalignment. An RF generator and horn antenna direct energy onto a track rail that acts as a traveling wave antenna. An antenna near a potential discontinuity radiates RF energy, the amount of energy radiated being related to the amount of misalignment in the track. If radiated energy exceeds a certain threshold, a receiver energizes an alarm that announces a misalignment.

Abstract: A flexible nose assembly for an underwater vehicle provides increased energy-absorbing capabilities and facilitates recovery and handling of the vehicle. The flexible nose assembly includes a flexible nose cap, at least one retrieval device, and at least one cable that is strong in tension, yet weak in compression which is coupled between the retrieval device and the UUV body. The flexible nose cap has a gap formed therein allowing the communication of environmental water into the region between the vehicle body and the nose cap. Optionally, the retrieval device may be recessed into the flexible nose assembly, thereby reducing hydrodynamic drag and overall vehicle length. Energy-absorbing ballast can be positioned within the nose cap in order to further enhance survivability.

Abstract: Accordingly there is provided a class specific classifier for classifying data received from a data source. The classifier has a feature transformation section associated with each class of data which receives the data and provides a feature set for the associated data class. Each feature transformation section is joined to a pattern matching processor which receives the associated data class feature set. The pattern matching processors calculate likelihood functions for the associated data class. One normalization processor is joined in parallel with each pattern matching processor for calculating an inverse likelihood function from the data, the associated class feature set and a common data class set. The common data class set can be either calculated in a common data class calculator or incorporated in the normalization calculation. The inverse likelihood function is then multiplied with the likelihood function for each associated data class.