General Electric Company

John J Bloomer

William E Engeler

Matthew N O'Donnell

Aiman A Abdel-Malek

John T Pedicone

Fathy F Yassa

John Erik Hershey

Michael James Hartman

Richard I Hartley

Bruce Gordon Barnett

Andrew Walter Crapo

Steven P Roehm

Barbara Jean Vivier

Hsuan Chang

Chukka Srinivas

A system for determining a maximum length digital sequence is constructed by selecting a Mersenne Prime integer and a primitive polynomial having an ORDER equal to the Mersenne Prime integer. An arbitrarily selected mask m is either provided to the transmitter and receiver, or constructed, at either, or both. The mask is used to create a decimated M sequence, and work backwards to define a recursion rule vector r which is associated with another primitive polynomial corresponding to the decimated M sequence. This recursion rule vector r is used to create a new feedback shift register which produces a maximum length sequence. An initialization vector i is provided to the transmitter and receiver and used as an initial load of the shift register. A selected stage of this register is exclusive-ORed ('XORed') with each bit of a plaintext message to be sent to result in cipher text. At the receiver, the same process is performed with the same mask m, and initialization vector i, to create the same recursion rule vector r, and shift register. The same stage of this shift register is then XORed with the received ciphertext message to result in the original plaintext message.

Digital information privacy system

A system and method for managing faults in a distributed system. The fault management system includes a configuration manager that maintains configuration information of components used in the distributed system. A plurality of measurement agents obtain performance information from the components in the distributed system. A diagnostic system has a plurality of rules written according to the configuration information stored therein. The diagnostic system is coupled to the configuration manager and each of the plurality of measurement agents and identifies faults occurring in the distributed system and provides solutions for correcting the faults The diagnostic system receives the configuration information from the configuration manager and the performance information from the plurality of measurement agents and uses the configuration and performance information with the plurality of rules to identify faults and provide solutions for the faults.

System and method for managing faults in a distributed system

A fluoroscopic imager for observing a living creature with reduced x-ray dosage uses a video monitor for displaying frames of image samples received during respective ones of frame scan intervals that regularly and successively occur at a display frame rate sufficiently high that brightness flicker is acceptably low to a human observer; an x-ray source that can be gated on for intervals not as long as a display frame; and a fluoroscopic camera, including a raster-scanning video camera and x-ray-to-light conversion apparatus with persistence not appreciably longer than a display frame and frame-filling apparatus. Especially during purely diagnostic procedures, the frame-filling apparatus generates a continuous succession of frames of image samples at the display frame rate by interpolating between successively grabbed frames of image samples. During procedures in which interpolating between successively grabbed frames of image samples introduces unacceptable delay in the observed image, the frame-filling apparatus generates the continuous succession of frames of image samples by extrapolating from each most recently grabbed frame.

Fluoroscopic imager with frame-filling apparatus

An interactive system for producing acceptable quality fluoroscopy images determines X-ray tube photon count and voltage while minimizing X-ray radiation dosage to a subject. Parameters of the subject and the type of image to be produced are provided to the system. X-ray tube voltage U and photon count Q are initialized at a fraction of conventional values for a portion of a subject to be imaged. An image is created and sectioned into rectangles. Rectangles having the greatest and least gradient values are used to determine variances indicating signal and noise power respectively. Images are produced and adjusted until the maximum transmitted power is reached, or the signal-to-noise ratio does not increase beyond a quality increment. The process is repeated to optimize X-ray tube voltage. The X-ray fluoroscopy procedure is then performed with the optimum X-ray tube photon count and the optimum X-ray tube voltage thereby reducing X-ray dosage. The optimization is repeated periodically to readjust the system.

X-ray dose reduction in pulsed systems by adaptive X-ray pulse adjustment

An interactive system for producing acceptable quality fluoroscopy images determines X-ray tube photon count and voltage while minimizing X-ray radiation dosage to a subject. Parameters of the subject and the type of image to be produced are provided to the system. X-ray tube voltage and current are initialized at a fraction of conventional values for a portion of a subject to be imaged. An image is then created and transformed. A power ratio of low frequency components to high frequency components is calculated indicating quality of the image. Images are produced and adjusted until the maximum exposure is reached, or the power ratio does not increase beyond a quality increment. The process is repeated to optimize X-ray tube voltage. The X-ray fluoroscopy procedure is performed with the optimum X-ray tube photon count and the optimum voltage thereby reducing X-ray dosage. The optimization is repeated periodically to readjust the system.

X-ray fluoroscopy system for reducing dosage employing iterative power

A method for fluoroscopically observing a living creature with reduced x-ray dosage is usable with a video monitor for displaying frames of image samples received during respective ones of frame scan intervals that regularly and successively occur at a display frame rate sufficiently high that brightness flicker is acceptably low to a human observer; an x-ray source that can be gated on for intervals not as long as a display frame; a fluoroscopic camera, including a raster-scanning video camera and a x-ray-to-light conversion apparatus with persistence not appreciably longer than a display frame; and frame filling apparatus for grabbing frames of image samples and interpolating between successively grabbed frames of image samples, when necessary, to generate frames of image samples at said display frame rate. During ones of said successive frame scan intervals, x-ray radiation is directed from the gated x-ray source through the living creature; the x-ray shadow of at least a portion of the living creature is viewed with the fluoroscopic camera; and the frame filling apparatus grabs frames of image samples from the raster-scanning video camera to be stored in frame stores and used as bases from which to compute fill frames of image samples. The frame filling apparatus continuously supplies to the video monitor the frames of image samples it generates at display frame rate.

Fluoroscopic method with reduced x-ray dosage

A method for dynamic focus of received energy, in a vibratory energy imaging system, into a beam in which contribution from transducers in an array of N such transducers, are progressively enabled to contribute to beam focussing dependent upon distance between a particular j-th transducer (where 1.ltoreq.j.ltoreq.N) is responsive to the depth, or range R, of the focal point at any instant of time; the initial steering angle .theta., with respect to the array normal, is used in conjunction with a range clock, to determine the time when each off-normal transducer channel is enabled to add to the beam (dynamic apodization) and to finely adjust the channel time delay to properly focus the beam after the enablement of the channel.

Dynamic phase focus for coherent imaging beam formation

Apparatus for providing a desired output signal as a function of a single-valued input signal in an electronic system, includes: an addressable memory, having a plurality L locations, each for storage of a data word of B bits; a circuit for storing in each of the L locations of the memory means a B-bit data word having a value selected to provide a particular output value; and circuitry for converting a present single-valued increment of input signal to a unique address, within the range of allowable locations of the memory, to cause each increment of input signal to select the associated one of the L data word locations, from which to output corresponding data.

Apparatus for implementation of desired input/output function in an

Apparatus for testing data conversion/transfer functions in each of a plurality N of channels of a vibratory energy imaging system includes a multiplexer for providing, to an addressable memory having a plurality of L=2.sup.M locations in each of which a data word of B bits can be stored, a selected one of an input data word and a test data word, each of which can address one of the L locations of the memory means. The address multiplexer facilitates retrieval from memory of a B-bit data word having a value selected to implement a selected function for that channel, so that comparision of data from the selected test address with the data which has been sent to that location for storage, will indicate if proper data is stored for carrying out the designated function.

Apparatus for testing data conversion/transfer functions in a vibratory

A method for correcting data conversion/transfer errors in each of a plurality N of channels of a vibratory energy imaging system, by: providing an addressable memory having a plurality L=2.sup.M locations, each for storage of a data word of B bits; then storing in each of the L locations of the memory means a B-bit data word having a value selected to cause the output-to-input transfer function for that channel to assume a desired relationship, with respect to a standard transfer measure; and selecting that one of the L data word locations, responsive to that actual one of an M-bit data word output from a channel ADC or from a data bus, responsive to a test signal, in which to place corresponding data.

Methods of correcting data conversion/transfer errors in a vibratory

A method for generating a stream of digital data words, each representing an analog signal amplitude from a beam of vibratory energy received by a plurality N of transducers each associated with one of a like number of separate channels of a phased array, uses the steps of: sampling, after a delay of a multiple number of cycles at a fixed frequency F, an analog input signal in each channel at a fixed frequency F for conversion to a digital data word at each sample; then demodulating the digital data word stream in each channel to baseband and reducing the data word rate by a factor D; and phase-rotating the baseband data stream of each channel by a phase difference .DELTA..phi. determined by the focal range R and steering angle .theta. to obtain, along both the sampling delay, a different channel time delay t.sub.d,j, for each j-th channel, where 1.ltoreq.j.ltoreq.N, necessary to steer and focus the beam to a desired angle/range combination. Apparatus for generating the stream of digital data words is disclosed, and uses a special output-switching section in each channel to allow a pipelined coherent summation to be obtained across the entire phased transducer array.

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Schenectady, NY, United States of America

John J Bloomer