Abstract: An adaptive data compression system is reset when performance drops below a predetermined threshold to permit greater compression of long files with evolving distributions of symbol combinations. The compression system uses a resettable dictionary in which initially unassigned codes are strategically assigned to symbol combinations as they are encountered in the data stream.The difference between the bit-lengths of corresponding lengths of the compressor input and output is compared with a value representing a predetermined performance threshold. The dictionary can be reset if the actual performance falls below the performance threshold. The reset can be inhibited while the dictionary is less than half-full to ensure that performance measures are statistically significant. However, if the performance is such that data expansion is occurring, reset is not so delayed.

Abstract: The trichromatic beamsplitter consists of composited dichroic beamsplitter plates that separate a projected image into its three color components with spacial as well as spectral precision. The three linear array photosensor comprises a monolithic sensor having three parallel photodiode arrays spaced precisely to accept the color component images of the trichromatic beamsplitter.

Abstract: A retaining wall system which uses rigid tieback elements having portions, column portions and web portions and wall panels disposed between the tieback elements. The tieback elements are designed to produce arching in the soil to reduce bearing stresses on the soil below base portions of the tieback elements by providing web portions sufficiently large to produce a complete ditch condition in the soil upon movement of the rigid tieback elements. This provides an economical retaining wall system in which multiple tiered walls can be spaced by an amount sufficient to produce a complete ditch condition. The wall can be implemented as a vertical wall or as a battered wall.

Abstract: A cable terminal which connects two woven ribbon cables and has a terminal connector which is capable of engaging standard device connectors. A switch mounted in the cable terminal provides selective interconnection of the woven ribbon cables in the cable terminal which allows the channel to be fed back when the cable terminal is unplugged. The cable terminal can be employed in a tag cable for computer applications. The cable terminal utilizes a housing which can be disassembled for repair of conductive connections within the cable terminal. The cable terminal employs a PC board which provides two-sided termination with a separate connector for each signal wire to reduce termination time. Additionally, mass ground terminators are also provided to reduce termination time. Teeth are incorporated within the structure of the housing to engage the woven ribbon cable so as to provide strain relief between the woven ribbon cable and the PC board.

Abstract: A control system for moving a piston in a reciprocating piston respirator which utilizes predictive servo control techniques. Present invention uses nonlinear time domain analysis rather than linear frequency domain analysis to produce a predictive servo control system for precisely controlling the movement of a piston in a reciprocating piston respirator. A plurality of flow profiles can be produced using stored factor tables. Current pressure and position information are used in the predictive servo control system.

Abstract: A unitary, self-contained card (10) which does not require interaction with a fixed terminal device to prevent monitoring of confidential information contained within the card (10). The unitary, self-contained card (10) has the ability to verify a personal identification number (PIN) which is entered directly into the card by way of a keyboard (12) without the use of an outside terminal and produce a transaction identification code (TIC) which varies for each transactional use of the card (10) and which can later be verified to determine the validity of the transaction. The card (10) is capable of storing issue and expiration dates, credit limit balances and other card transactional data. The card (10) can be used in conjunction with a validation system (102) with provisions for verifying information recorded on the magnetic indicia (22) of the card (10).

Abstract: An inclinometer for producing high resolution signals of inclination relative to various references and which is capable of displaying inclination angles in various modes. High resolution data signals are produced through the use of a digital encoding wheel which is suspended in equilibrium in a fluid to substantially eliminate frictional forces. A microprocessor, or state logic machine is used to analyze and process the data to provide various displays of inclination including an audible output.

Abstract: A retaining wall system utilizing a support structure formed from standard concrete Tee forms. The structural members are assembled using post tensioning devices which impart added strength to the component members. Wall can be employed in a tier configuration, can utilize cross tie members, counterbalancing slabs and foot support devices to offset bending moment forces. The base member can be formed in a Tee configuration or as a single slab unit. The invention can utilize continuous footers and retaining flanges for holding the wall segments.

Abstract: A force and multiplication control valve which utilizes ball leverage to produce multiplied forces on a ball lock seat device. Constantly changing wear surfaces provide self-cleaning and self-compensating wear characteristics to provide extremely high reliability of the device of the present invention. Non-hardened metals can be used because of the self-compensating wear characteristics. High pressures can be handled by the valve of the present invention because of the ability to use metals for metal contact surfaces to produce a valve seal. Additionally, the present invention can be used with many fluids which would normally be corrosive to materials used in valves employing rubber-type seals. The device can be configured to act as a pressure regulator control valve, a solenoid valve and can be used with various fluids including gases and liquids.

Abstract: A wide range radioactive gas concentration detector and monitor which is capable of measuring radioactive gas concentrations over a range of eight orders of magnitude. The device of the present invention is designed to have an ionization chamber which is sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.

Abstract: A device and method for optical pumping in a whispering mode optical waveguide. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature for confining the beam to increase intensity. An optical pumping medium is disposed in the optical path of the beam as it propagates along the waveguide. Optical pumping is enhanced by the high intensities of the beam and long interaction pathlengths which are achieved in a small volume.

Abstract: A fixed-pitch wind turbine system utilizing a permanent magnet alternator. Optimum output power is achieved by controlling the load on the stator output armature of the permanent magnet alternator. Energy is stored in the ac utility grid utilizing a synchronous inverter which couples energy from the alternator for storage in the ac utility grid in a controlled manner to regulate the rotational speed of the wind turbine and thereby extract a substantially optimum amount of output power from the wind turbine.

Abstract: A device and method for optically pumping a gaseous laser using blackbody radiation produced by a plasma channel which is formed from an electrical discharge between two electrodes spaced at opposite longitudinal ends of the laser. A preionization device which can comprise a laser or electron beam accelerator produces a preionization beam which is sufficient to cause an electrical discharge between the electrodes to initiate the plasma channel along the preionization path. The optical pumping energy is supplied by a high voltage power supply rather than by the preionization beam. High output optical intensities are produced by the laser due to the high temperature blackbody radiation produced by the plasma channel, in the same manner as an exploding wire type laser. However, unlike the exploding wire type laser, the disclosed invention can be operated in a repetitive manner by utilizing a repetitive pulsed preionization device.

Abstract: A self-supporting uniformly redundant array pattern for coded aperture imaging. The present invention utilizes holes which are an integer times smaller in each direction than holes in conventional URA patterns. A balance correlation function is generated where holes are represented by 1's, nonholes are represented by -1's, and supporting area is represented by 0's. The self-supporting array can be used for low energy applications where substrates would greatly reduce throughput. The balance correlation response function for the self-supporting array pattern provides an accurate representation of the source of nonfocusable radiation.

Abstract: A combination regenerative ring and backward Raman waveguide amplifier and a combination regenerative ring oscillator and backward Raman waveguide amplifier which produce Raman amplification, pulse compression, and efficient energy extraction from the CO.sub.2 laser pump signal for conversion into a Stokes radiation signal. The ring cavity configuration allows the CO.sub.2 laser pump signal and Stokes signal to copropagate through the Raman waveguide amplifier. The backward Raman waveguide amplifier configuration extracts a major portion of the remaining energy from the CO.sub.2 laser pump signal for conversion to Stokes radiation. Additionally, the backward Raman amplifier configuration produces a Stokes radiation signal which has a high intensity and a short duration. Adjustment of the position of overlap of the Stokes signal and the CO.sub.2 laser pump signal in the backward Raman waveguide amplifiers alters the amount of pulse compression which can be achieved.

Abstract: Sensor and method of fabricating a sensor for detecting relative humidity with a substantially linear response from 0% to 100% and also detecting temperature. The sensor utilizes a unique essentially pure Al.sub.2 O.sub.3 layer which has a disordered crystalline structure and a density gradient which varies from a low density at its lower surface to a higher density at its upper surface which together produce the desired linear response to relative humidity.The sensor is employed as a three-terminal semiconducting device which is biased with d.c. current, allowing implementation with standard ICs and LSI circuitry. Application of a biasing current on the top electrode allows the RH sensor to be operated simultaneously as a temperature sensor.Also disclosed is a relative humidity detector system for adjusting sensitivity of the sensor for changes in environmental temperature so as to provide a true linear relative humidity response. Periodic discharge of the d.c.

Abstract: A homodyne radar transmitter/receiver device which produces a single combined output which contains modulated backscatter information for all phase conditions of both modulated and unmodulated backscatter signals. The device utilizes taps along coaxial transmission lines, strip transmission line, and waveguides which are spaced by 1/8 wavelength or 1/6 wavelength, etc. This greatly reduces costs by eliminating separate transmission and reception antennas and an expensive arrangement of power splitters and mixers utilized in the prior art.

Abstract: A system utilizing uniformly redundant arrays to image non-focusable radiation. The uniformly redundant array is used in conjunction with a balanced correlation technique to provide a system with no artifacts such that virtually limitless signal-to-noise ratio is obtained with high transmission characteristics. Additionally, the array is mosaicked to reduce required detector size over conventional array detectors.

Abstract: A device and method for Raman scattering in a whispering mode optical waveguide. Both a helical ribbon and cylinder are disclosed which incorporate an additional curvature .rho. p for confining the beam to increase intensity. A Raman scattering medium is disposed in the optical path of the beam as it propagates along the waveguide. Raman scattering is enhanced by the high intensities of the beam and long interaction path lengths which are achieved in a small volume.

Abstract: A device for detecting imminent failure of a high-dielectric stress capacitor utilizing circuitry for detecting pulse width variations and pulse magnitude variations. Inexpensive microprocessor circuitry is utilized to make numerical calculations of digital data supplied by detection circuitry for comparison of pulse width data and magnitude data to determine if preselected ranges have been exceeded, thereby indicating imminent failure of a capacitor. Detection circuitry may be incorporated in transmission lines, pulse power circuitry, including laser pulse circuitry or any circuitry where capacitors or capactior banks are utilized.