Abstract: A loop gain processing scheme for a speakerphone arrangement determines system loop gain according to two echo feedback paths within the speakerphone system. Gain values for each half-loop are calculated separately to ensure that both the local and far end telephone or speakerphone system are stable. A first half-loop includes gain contributions from a feedback path extending from a local speakerphone microphone to a hybrid line interface, which couples the speakerphone to the telephone network line, and subsequently to a local loudspeaker. A second half-loop defines a feedback path from a line receive channel to a transmit channel. Gain contributions are input into a system controller which determines gain values for each of the half-loops to accurately set the proper gain switching mode.

Abstract: A system for actively monitoring and controlling the effective ambient temperature in an application utilizing a fluorescent tube as the source of illumination. The system is the combination of a fluorescent tube, which may be thermally bonded to a reflector plate that is in physical contact with thermal electric cooler units and a heat sink. A temperature sensor in conjunction with drive circuitry and a power source, directs a magnitude and direction of current flow through the thermal electric cooler units thereby controlling the ambient operating temperature of the fluorescent tube.

Abstract: A system and method for monitoring and recording the mileage a truck travels within a particular state including a GPS receiver, an odometer, and a memory device which contains state boundary information and a processor for determining on a continual basis whether the positioned information received from the GPS receiver is in a particular state boundary and for recording mileage of the truck when the position and state boundary comparison determines that a change in state boundaries has occurred. Additionally, a storage device for storing the data output by the processor which includes the desired mileage within a particular state information is included.

Abstract: A hybrid focal plane array (FPA) structure including a soft, localized, and thick epoxy for supporting the FPA on a cooling device. The hybrid FPA arrangement includes a crystalline optical substrate with a layer of an optically sensitive material disposed on one surface of the substrate. The optically sensitive side of the substrate layer is coupled to a MUX chip via an interconnection scheme. The layered configuration of the detector, the optically-sensitive material, interconnection network, and the MUX is mounted to a platform or dewar cold plate with a pliable, thick epoxy which is locally deposited onto the platform to effectively form a raised mounting cushion which supports the MUX and reduces deleterious effects resulting form a close coupling of the FPA to the mounting platform.

Abstract: The present invention is a method for identifying a Most-Probable-Point (MPP) in original space obviating the need for a probability transformation, for use in first order/second order reliability analysis. It comprises generating the linear approximation of a limit-state-function, g(x) about the median, mean point, or mode of random variables, x of g(x). g(x) is defined so that g(x)f0 denotes a failure set. The Most-Probable-Point-Locus (MPPL) of g.sub.1, MPPL.sub.1, is constructed by the steps of: i) identifying the mode of x; ii) identifying the MPP of g.sub.1 (x)=c, where c is an arbitrary constant, and iii) constructing said MPPL.sub.1 by connecting said mode of x from step i), above, and the MPPs corresponding to different c's from step ii), above. A quadratic search algorithm is to identify point MPP.sub.1, the intersection of MPPL.sub.1 and g(x)=0, based on the following convergence criteria: ##EQU1## The process is then stopped, unless the convergence criteria are not satisfied. g.sub.

Abstract: A direct connect antenna includes a passive patch-type antenna mounted to a radio, wherein the need for and use of a coaxial cable extension arrangement is eliminated. Thus, the characteristic impedances of the load and source can be better matched, resulting in lower reflection and distributed losses. The antenna is formed with guide slots for alignment and simple snap-on connection of the antenna to the radio to prevent coaxial connector mismatch and damage. The radio may be directly affixed and electrically coupled to a PCMCIA compliant interface card which is insertable into a host computer. Accordingly, radio signals received by the direct connect antenna and radio arrangement are processed through the PC card and the computer.

Abstract: A wide viewing angle liquid crystal display and method of operating the same are disclosed. Each of a plurality of pixel elements of the display have individually driveable first and second pixel sub-elements. A desired average gray scale intensity for a first pixel element is determined. First and second drive voltages are determined as a function of the desired average gray scale intensity for the first pixel element. The first drive voltage is provided to the first pixel sub-element to drive it to a first gray scale intensity. The second drive voltage is provided to the second pixel sub-element to drive it to a second gray scale intensity. The average gray scale intensity for the first pixel element, which is a function of the first and second gray scale intensities, has reduced viewing angle dependence.

Abstract: A FOG design is disclosed that eliminates the need for spatially averaging the output of a readout optical fiber by using a short coherence length light source and decorrelating the orthogonal fiber modes in the birefringent readout optical fiber prior to them being received by the photodetector. The orientation of the optical output of the readout optical fiber with respect to the photodetector is at an angle other than normal incidence, which is designed to reduce the reflections from the photodetector back into the readout optical fiber. The coherence length of the source and the length and birefringence of the readout optical fiber are selected so that there is a complete decorrelation of the polarization states of the light as they pass through the readout optical fiber.

Abstract: A focal plane array (FPA) mounted in an imbalanced configuration including several layers of materials with differing thermal expansion coefficients (TECs), moduli of elasticity, and thicknesses to maintain surface planarity and improve the reliability of the FPA during thermal cycling and excursions. An optical substrate is coupled to a multiplexer through an array of indium bumps. The typical TEC mismatch between the optical substrate and the multiplexer is eliminated by forcing the multiplexer to exhibit an effective TEC equal to that of the optical substrate by particularly selecting the types of materials used and the thicknesses of the individual layers of the composite structure. Consequently, undesirable deflections and distortion of the multiplexer and the indium bumps are minimized, thereby substantially improving FPA reliability.

Abstract: A rotatable member is positioned coaxial with a joint between a first element and a second element. The joint defines an angle to be measured. The rotatable member has coded information thereon. First and second sensing heads are attached to respective elements. Coded information is arranged on the rotatable member so as to periodically pass in readable proximity to the sensing heads once every revolution of the rotatable member. A decoding system is provided for each sensing head. Each decoding system includes threshold circuitry, a state machine, and a pulse generator for providing a timing strobe. A first timer uses a timing strobe from the first sensing head for continuously determining the average elapsed time for one complete revolution of the rotatable member. A second timer uses timing strobes from the first and second sensing heads to continuously determine the average elapsed time for the coded information on the rotatable member to travel from the first sensing head to the second head.

Abstract: A navigation and guidance system which directs a user toward a desired destination. Position and steering information are integrated into a single display to allow the user to immediately determine whether the correct course is being traveled, and to inform the use of any directional changes which may be necessary to be directed toward the desired destination waypoint. The user's position and course are determined by a navigation system and indicated on the display as a directional pointing icon, such as a line or arrow. The destination is displayed as a point. The user's Point of Closest Approach (PCA) can then be calculated according to current position, course, and the position of the desired destination. As the use's course gets closer to the bearing of the destination waypoint the PCA indicator can correspondingly shift with the user's movements. By superimposing the PCA over the destination waypoint, the user may precisely steer his or her craft to the desired destination.

Abstract: A vehicle navigation system uses a one-multiplier Gray-Markel filter. The sign parameter of each stage of the filter is selected by an algorithm which limits the maximum signal passing through the filter, thereby preventing overflow.

Abstract: A hybrid focal plane array (FPA) structure including a Balanced Composite Structure (BCS) in which several layers of materials having differing thermal expansion coefficients stabilize the FPA during cryogenic cooling. An optical substrate with a layer of an optically sensitive material detects impinging radiation. The optically sensitive material is coupled to a multiplexer (MUX) substrate via interconnection bumps. The MUX is bonded to a layer of a material having a high TEC. A rigid core layer is sandwiched between the MUX and a balancing layer formed of a material having similar mechanical and geometrical characteristics to the MUX substrate. The three-layer BCS consisting of the MUX, the rigid core layer and the balancing layer is designed to have an effective TEC matching that of the optical substrate. The bumps and the optically sensitive material are thus protected from undesirable stresses generated during thermal excursions, thereby resulting in substantially improved FPA reliability.

Abstract: The present invention is a method for enhancing reaction rates when digesting chemical systems which form passivating layers. Particles are introduced into a digestion fluid bath. Digestion is allowed to proceed until passivating layers of digestion products have partially formed on the particles. The layers constitute a diffusion barrier to the digestion fluid and reduce the digestion rate. The particles are periodically conveyed through an ultrasonic beam to remove portions of the passivating layers. Thus, fresh surfaces of the particles are exposed to the digestion fluid bath. The periodic conveyance is such that a desired rate of digestion is obtained.

Abstract: The STREAMER FOR RISC DIGITAL SIGNAL PROCESSOR shown herein allows a CPU 46 to interface with a memory 60 via data registers 50. Pre-fetch and post-store of the correct address is determined by an address generator 58 according to a rule determined by a context register 52. An index indicative of this address is stored in an index register 54. The data, context, and index registers together form a streamer 56, streaming data between the CPU 46 and data memory 60. The rule of the context register 52 also drives a converter 62 for converting data between memory format and register format. The speed and flexibility of a RISC device is combined with the intensive memory access of a digital signal processor.

Abstract: A pyrochemical process is utilized to recover 99% of the remaining transuranium materials from plutonium-uranium extraction waste. One step of the overall pyrochemical process involves the electrochemical separation of the waste components. A solid anode and a solid cathode are used in this electrochemical separation step to electrorefine in single or multiple steps. The solid anode and solid cathode are selected from certain preferred anodic and cathodic materials. Where multiple electrorefining steps are used to obtain more complete electroseparation, this is achieved by employing in the multiple electrorefining steps both a solid anode, suitably graphite, and a molten metal anode containing a mixture of the actinide and rare earth elements. This results in greater separation than can be realized through electroseparation by use of either anode alone.

Abstract: A nonlinear optical material includes a noncentrosymmetric crystal of an anionic boron complex salt containing a cation and at least one organic ligand coordinated to a boron atom. The nonlinear optical crystal may consist of a compound having the formula A[BC.sub.2 ] where A is a monocation, B is boron, and C is the organic ligand, or a compound having the formula A[BC.sub.2 ].sub.2 where A is a dication, B is boron, and C is the organic ligand. The organic ligands may also be organic molecules having .alpha.-dihydroxy functionalities. Furthermore, the organic ligands may be selected from the group consisting of .alpha.-hydroxy carboxylic acids and 1,2-diols or from the group consisting of d-malic acid, d-lactic acid, d-tartaric acid, dimethyl-d-tartrate, diethyl-d-tartrate, l-malic acid, l-lactic acid, l-tartaric acid, dimethyl-l-tartrate, diethyl-l-tartrate, and ethylene glycol.

Abstract: An accurate estimate of the amplitude of a sparsely sampled sinusoidal signal is obtained by filtering the squares of the sampled values of the sinusoidal signal with an adjustable notch filter in order to remove a double-frequency component at twice the frequency of the sinusoidal signal. This amplitude estimate, for example, is used for automatic gain control of the amplitude of the sinusoidal signal. Preferably, the notch filter is a digital filter for computing an output signal (v) from successive samples (x.sub.n, x.sub.n-1, x.sub.n-2) of an input signal (x) according to: v.sub.n =x.sub.n -.beta.x.sub.n-1 +x.sub.n-2. The frequency control parameter (.beta.) is computed, so as to automatically track the frequency of the sinusoidal signal, by integrating a product of a derivative (x.sub.n-1 -x.sub.n-2) of the input signal (x) and a derivative (v.sub.n -v.sub.n-1) of the filtered signal (v).

Abstract: A tube nozzle having a thermal insulative barrier in it to prevent thermal fatigue cracks due to thermal transients in tube nozzles for all kinds of pipe joints that carry fluids with temperatures that change rapidly. This is particularly useful in mixing tees, where two different temperature fluids meet. The use of this invention could increase safety and reliability of processing streams in processing plants involving fluids maintained at various constant or fluctuating temperatures.

Abstract: For use with a quartz angular rate sensor, a frequency and phase-locked synthesizer recovers a reference signal virtually free of phase noise, and generates a quadrature-phase reference signal for complex demodulation of the angular rate signal. The synthesizer also ensures a precisely adjusted phase shift of approximately zero across the drive tines of the sensor. Moreover, the digital synthesizer provides a precise numerical indication of the drive frequency, which can be used for compensation and automatic tuning of filters, such as a tracking filter, a filter in an automatic gain control, and notch filters in the phase and/or frequency detectors in the digital synthesizer. The tracking filter is used as a pre-filter for the synthesizer, and is responsive to a passband-width control signal generated from the magnitude of the frequency and phase error signal controlling the frequency generated by the synthesizer.