Other

USA As Represented by Secretary of the Navy

Leland Stanford Junior University

Gas Research Institute

Cardinal Sound Labs, Inc.

Western Atlas International, Inc.

Tomex Corporation

Bernard Widrow

James R Zeidler

Bruce P Marion

John M McCool

James Rector

Iraj A Salehi

Juan Carlos Aragon

Brian Mitchell Percival

Robert H Hearn

Douglas M Chabries

Randall H Moore

Maurice N Brearley

Michael A Lehr

Designs for cognitive memory systems storing input data, images, or patterns, and retrieving it without knowledge of where stored when cognitive memory is prompted by query pattern that is related to sought stored pattern. Retrieval system of cognitive memory uses autoassociative neural networks and techniques for pre-processing query pattern to establish relationship between query pattern and sought stored pattern, to locate sought pattern, and to retrieve it and ancillary data. Cognitive memory, when connected to computer or information appliance introduces computational architecture that applies to systems and methods for navigation, location and recognition of objects in images, character recognition, facial recognition, medical analysis and diagnosis, video image analysis, and to photographic search engines that when prompted with a query photograph containing faces and objects will retrieve related photographs stored in computer or other information appliance, and will identify URL's of related photographs and documents stored on the World Wide Web.

Cognitive memory and auto-associative neural network based search engine for computer and network located images and photographs

System and method for cognitive memory and auto-associative neural network based pattern recognition

This invention provides designs for communication systems that use adaptive filters in circuits whose purpose is to enable two-way transmission of information signals in the same frequency band at the same time over twisted pair channels, coaxial cable channels, fiber optic channels, or wireless channels. The methodology allows two-way DSL transmission over telephone lines, making use of existing DSL hardware and signal standards, so that the upload speed is increased by an approximate factor of ten. Applied to wireless systems with single antennas at the two ends of the channel, a doubling of the data rate is achieved for a given bandwidth. Applied to wireless systems with 2-way adaptive antenna arrays at a central location and a 2-way adaptive antenna array at each of a plurality of subscriber locations, the data rate for a given bandwidth is increased by a large factor.

Simultaneous two-way transmission of information signals in the same frequency band

A directional acoustic receiving system is constructed in the form of a necklace including an array of two or more microphones mounted on a housing supported on the chest of a user by a conducting loop encircling the user's neck. Signal processing electronics contained in the same housing receives and combines the microphone signals in such a manner as to provide an amplified output signal which emphasizes sounds of interest arriving in a direction forward of the user. The amplified output signal drives the supporting conducting loop to produce a representative magnetic field. An electroacoustic transducer including a magnetic field pickup coil for receiving the magnetic field is mounted in or on the user's ear and generates an acoustic signal representative of the sounds of interest. The microphone output signals are weighted (scaled) and combined to achieve desired spatial directivity responses. The weighting coefficients are determined by an optimization process. By bandpass filtering the weighted microphone signals with a set of filters covering the audio frequency range and summing the filtered signals, a receiving microphone array with a small aperture size is caused to have a directivity pattern that is essentially uniform over frequency in two or three dimensions. This method enables the design of highly-directive hearing instruments which are comfortable, inconspicuous, and convenient to use. The invention provides the user with a dramatic improvement in speech perception over existing hearing aid designs, particularly in the presence of background noise and reverberation.

Directional hearing system

Disclosed is a convenient way of mounting the microphone array and associated electronics of a hearing aid on the person, and providing a convenient wireless means for delivering the microphone signals to the ear, and providing a signal processing technique that yields sharp directivity at audio frequencies. The wearer positions her/his body to receive the desired signal and to attenuate surrounding background noise and multipath interference.

Directional hearing aid

An apparatus (10) for providing while drilling information on a subterranean geologic formation (28) includes a drilling rig (12) and a rotary drill bit (18) attached to the drilling rig (12) for providing seismic waves as it drills in the earth (16). Geophones (20) are spaced from the rotary drill bit (18) in the earth (16) and receive in direct seismic wave paths (26) and seismic wave paths (30) reflected from the subterranean geologic formation (28) the seismic waves provided by the drill bit (18). A reference sensor (24) is located on the drilling rig (12). The seismic signals sensed by the reference sensor (24) and by the geophones (20) are cross-correlated to separate the drill bit generated signals from interference signals by combining the reference signals and the signals received by the geophones (20). The cross-correlated reference signals and the signals received by the geophones (20) are separated into a first group of the drill bit generated seismic signals travelling to the geophones (20) in direct paths and a second group of the drill bit generated seismic signals travelling to the geophones (20) in paths reflected from the subterranean geologic formation (28). The cross-correlation provides a domain where drill bit generated energy can be distinguished from interference. The two groups of the drill bit generated seismic signals can then be used to image the subsurface seismically so as to improve the chances of discovering hydrocarbons. The techinque is applicable to land operations and to drilling from an offshore platform over water.

Signal processing to enable utilization of a rig reference sensor with a

An apparatus (10) for providing while drilling information on a subterranean geologic formation (28) includes a drilling rig (12) and a rotary drill bit (18) attached to the drilling rig (12) for providing seismic waves as it drills in the earth (16). Geophones (20) are spaced from the rotary drill bit (18) in the earth (16) and receive indirect seismic wave paths (26) and seismic wave paths (30) reflected from the subterranean geologic formation (28) the seismic waves provided by the drill bit (18). A reference sensor (24) is located on the drilling rig (12). The seismic signals sensed by the reference sensor (24) and by the geophones (20) are cross-correlated to separate the drill bit generated signals from interference signals by combining the reference signals and the signals received by the geophones (20). The cross-correlated reference signals and the signals received by the geophones (20) are separated into a first group of the drill bit generated seismic signals travelling to the geophones (20) in direct paths and a second group of the drill bit generated seismic signals travelling to the geophones (20) in paths reflected from the subterranean geologic formation (28). The cross-correlation provides a domain where drill bit generated energy can be distinguished from interference. The two groups of the drill bit generated seismic signals can then be used to image the subsurface seismically so as to improve the chances of discovering hydrocarbons. The techniques is applicable to land operations and to drilling from an offshore platform over water.

An apparatus (10) for determining while drilling in the earth with a drill bit (12) the positions of seismic wave reflecting geologic formations (15, 17) has seismic wave sensors (A, B) positioned in the earth near its surface (42). The sensors (A, B) are disposed at known positions with respect to the borehole. The drill bit (12) generates the seismic waves. The sensors (A, B) receive the seismic waves both directly and by reflection from the geologic formations (15, 17). Adaptive filters (20, 26) are connected to each of the sensors (A, B). A summing circuit (34) receives outputs from the adaptive filters (20, 26). The converged impulse responses of the adaptive filters provide information about the amplitude of the reflected waves and their arrival times at the surface, thus allowing detection of the reflecting horizons and their location and physical characteristics.

Seismic processing and imaging with a drill-bit source

An apparatus (10) for providing while drilling information on a subterranean geologic formation (28) includes a drilling rig (12) and a rotary drill bit (18) attached to the drilling rig (12) for providing seismic waves as it drills in the earth (16). Geophones (20) are spaced from the rotary drill bit (18) in the earth (16) and receive in direct seismic wave paths (26) and seismic wave paths (30) reflected from the subterranean geologic formation (28) the seismic waves provided by the drill bit (18). A reference sensor (24) is located on the drilling rig (12). The seismic signals sensed by the reference sensor (24) and by the geophones (20) are cross-correlated to separate the drill bit generated signals from interference signals by combining the reference signals and the signals received by the geophones (20). The cross-correlated reference signals and the signals received by the geophones (20) are separated into a first group of the drill bit generated seismic signals travelling to the geophones (20) in direct paths and a second group of the drill bit generated seismic signals travelling to the geophones (20) in paths reflected from the subterranean geologic formation (28). The cross-correlation provides a domain where drill bit generated energy can be distinguished from interference. The two groups of the drill bit generated seismic signals can then be used to image the subsurface seismically so as to improve the chances of discovering hydrocarbons. The technique is applicable to land operations and to drilling from an offshore platform over water.

A pump is coupled through a discharge line to a wellbore, which in turn intersects a fracture, the wellbore and fracture being filled with fluid to form a fluid system. Sensors are located in position at the top and, under certain circumstances, at the bottom of the wellbore. The dimensions of the fracture are calculated from data generated by the sensors by analyzing the incident and reflected waves within the fluid system the acoustic waves being generated by pressure pulses from a pump and travel from the pump through the fluid into the fracture. In preferred embodiments of this invention, transfer functions are developed by analysis of the data, so that the data recorded by sensors at the top of the wellbore accurately represent pressure fluctuations at the bottom of the wellbore. Transfer functions relating pressure fluctuations at the top of the wellbore to pressure fluctuations at the bottom of the wellbore, i.e., at the mouth of the fracture, exhibit resonant phenomena in the fracture from which fracture length can be determined. A Fourier transform is generated of transfer fucntions relating the impulse at the top of the annulus to the impulse response at the fracture entrance and through the fracture, to provide a time domain analysis of the waves in the fracture. This way, travel times of waves in the fracture can be determined, and this data used to estimate the length and height of the fracture, given that the wave speed in the fracture is known.

Estimation of hydraulic fracture geometry from pumping pressure

A pair of sensitive microphones or transducers are mounted on a user's body, spaced apart by a distance equal to one-half a wavelength of the center frequency of a range of frequencies to be emphasized. By summing the outputs of the two microphones, sound in the broadside or look direction (i.e., the direction the listener faces, the microphones being on a line perpendicular to this direction) are emphasized; sounds in the endfire or side directions are nulled or produce a substantially null response in the region of the center frequency defined by the microphone spacing. A third microphone may be added that is not equally spaced from the microphones on either side, but is spaced to provide half wavelength distances which define maximum and null responses centered at the other points within the frequency range (1-4 KHz) desirable for highly effective hearing. The summed signal from each mircophone pair is bandpass filtered. Three bandpass filters are used. The centers of their pass bands are 1200 Hz, 2250 Hz, and 3600 Hz, respectively. Thus each microphone pair and associated bandpass filter is responsible for providing a directonal receiving capability in its assigned range of frequencies. The frequency ranges are contiguous and overlap slightly. The final output is obtained by summing and amplifying the bandpass filter outputs. A good bandpass filter design is a fourth order Butterworth filter, whose center frequency can be designed to be: ##EQU1##

Seismic exploration method and apparatus in which interference signals received by the sensing geophones from the seismic vibration source are cancelled by employing a signal representative of the seismic vibration source and combining it with the output from the sensing geophones.

Seismic exploration method and apparatus for cancelling interference

A technique utilizing a combination of adaptive noise cancelling and conventional signal processing is developed to enhance electrocardiographic monitoring in the operating room by reducing the noise interference that is created by an electrosurgical instrument. Significant amounts of interference are eliminated by radio frequency shielding, passive and active lowpass filtering and optical isolation. A digital adaptive canceller using the least-mean-square algorithm is used to reduce the remainder of the interference, yielding an improvement in signal-to-noise ratio of approximately 100 dB.

Growing community of inventors

Stanford, CA, United States of America

Bernard Widrow