Abstract: An electrically heated soldering device adapted to simultaneously heat a plurality of spaced electrical elements in a reflow soldering operation includes an elongated metal laminate of substantially U-shaped cross section having a bight portion between two side portions which may be parallel or divergent. The laminate includes a layer of aluminum between a layer of copper and a layer of stainless steel, with the layers being roll bonded together. The copper and aluminum layers are removed at the bight portion to expose the stainless steel layer and form a heat generating zone for contacting the plurality spaced electrical elements which is corrosion resistant and nonwettable by solder. The edges of the copper and aluminum layers adjacent to the exposed stainless steel bight portion are shaped to impart a selectable temperature profile, either uniform or non-uniform along the length of the bight portion.

Abstract: A protection circuit for communication equipment connected to a two conductor communication line includes a bridge rectifier having alternating current terminals connected to the conductors and to ground. The direct current terminals of the rectifier are connected to a device responsive to a range of predetermined voltage and current conditions in the conductors for reflecting foreign electrical energy.

Abstract: This speech recognizer concatenates a string of reference isolated-words for comparison with the unknown string of connected-words. The invention includes a level-building (LB) algorithm, "level" implying a location in a sequence of words. A constrained endpoint dynamic-time-warp algorithm, in which the slope of the warping function is restricted between 1/2 and 2, is used to find the best alignment between an unknown continuous-word test pattern, and a concatenated sequence of L reference patterns. Properties of the LB algorithm include: modification of the references; back-track decision logic; heuristic selection of multiple candidates, and syntax constraints. As a result, the processing required is less than two-level dynamic-program-matching and sampling algorithms.

Abstract: In a transmission system, reconstruction of a portion of the signal lost in transmission is based on signal encoding at the transmitter, and decoding at the receiver; at the transmitter, sequential portions of the signal are intermixed to form encoded portions, and autocorrelation factors (waveform feature signals) of the original portions are added to each encoded portion to form a packet; at the receiver, any missing packet is reconstructed from the adjacent received packet.

Abstract: In a speech communication system, an input speech signal is partitioned into a plurality of subband portions. Responsive to each subband portion, a signal of lesser bandwidth representative of the subband portion is generated by dividing the instantaneous phase of the subband by an integer k. Where k=2, for example, the center frequency and bandwidth of each subband is halved. The lesser bandwidth subband portion representative signals are combined to form a compressed bandwidth signal representative of the input speech signal. A replica of the input speech signal is formed by partitioning the compressed bandwidth signal into subband portions thereof; converting each compressed signal subband portion into a signal representative of a subband of the input speech signal; and combining the converted subband representative signals into a single speech signal replica.

Abstract: A capstan winch for pulling cable through conduit includes means for measuring the torque applied to the capstan and a take-up reel. The torque measuring means comprises an inner drum connected by a tension spring to a concentric outer drum. A patterned disc on the inner drum is visible through a window in the outer drum. The pattern indicates the relative position of the inner and outer drums, which is correlated to the applied torque.

Abstract: An arrangement for endpoint detection improves speech recognition accuracy and lowers rejection rates by developing an ordered list of endpoint candidates. A triple thresholding technique defines energy signal pulses. The energy pulses are combined according to predetermined criteria to form the endpoint candidates.

Abstract: In a speaker recognition and verification arrangement, acoustic feature templates are stored for predetermined reference words. Each template is a standardized set of acoustic features for one word, formed for example by averaging the values of acoustic features from a plurality of speakers. Responsive to the utterances of identified speakers, a set of signals representative of the correspondence of the identified speaker's features with said feature templates of said reference words is generated. An utterance of an unknown speaker is analyzed and the reference word sequence of the utterance is identified. A set of signals representative of the correspondence of the unknown speaker's utterance features and the stored templates for the recognized words is generated. The unknown speaker is identified jointly responsive to the correspondence signals of the identified speakers and unknown speaker.

Abstract: A string of input characters is recognized as one of a plurality of reference sets which are stored in predetermined groups. A set of signals representative of the correspondence of the input characters to the reference characters is generated. The input character string is identified responsive to the character correspondence signals. The character string identification comprises forming a set of signals each representative of the correspondence of the input character string to one of the predetermined groups responsive to the character correspondence signals. Jointly responsive to the character correspondence signals, the reference character sets and the group correspondence signals, the reference set that most closely corresponds to the input character string is selected.

Abstract: In a communication system an input predictive type signal is analyzed in successive time intervals to generate a set of prediction signals for the interval. A predictive residual signal is produced jointly responsive to the input signal and the interval prediction signals. The predictive residual signal is quantized and encoded. The quantization includes dividing the predictive residual signal into a plurality of distinct portions and selectively quantizing the distinct portions to improve intelligibility.

Abstract: Recognition of continuous speech by comparison with prestored isolated words may be confused by the merging together of spoken adjacent words (coarticulation). Improved recognition is attained by generating overlap-words, e.g., words whose first phoneme is the end phoneme of the preceding word in a string of words. The reference candidate series of overlap-words is transformed under dynamic time warping so as to time-match the utterance series of overlap-words.

Abstract: A speech controlled dialing circuit identifies input utterances which may be a command word (mode select), repertory word (dialing name or number), or non-recognized ("Other"). Responsive to the identification of each occurring input utterance, a set of predetermined templates are selected to identify the next occuring utterance. A programmed microprocessor system is described to implement the main controller function.

Abstract: Apparatus for the electrical protection of communication circuits includes an insulative base (e.g., 13) having a line terminal (e.g., 3) and a station terminal (e.g., 1). A fuse wire (e.g., 2) is enclosed within a cavity (e.g., 21) within the base (e.g., 13). The fuse wire (e.g., 2) is connected in series between the line terminal (e.g., 3) and the station terminal (e.g., 1). The cavity (e.g., 21) is filled with an arc-extinguishing material (e.g., 22) to prevent a power arc when the fuse wire (e.g., 2) melts.

Abstract: An arrangement reduces transmission errors in a communication system that includes a transmitter operative to convert an input signal into blocks of coded signals and a receiver operative to convert the coded blocks into a replica of the input signal. In the transmitter, a signal representative of first features of the input signal and a signal corresponding to second features of the input signal are generated. In the receiver, corrupted received coded signals are detected responsive to the first feature signal and the received blocks of coded signals. Each corrupted received coded signal is modified jointly responsive to the received blocks of coded signals and the second feature signal to reduce errors in the input signal replica.

Abstract: X-ray generation and detection apparatus for use in a computer assisted tomography system which permits relatively high speed scanning. A large X-ray tube having a circular anode (3) surrounds the patient area. A movable electron gun (8) orbits adjacent to the anode. The anode directs into the patient area X-rays which are delimited into a fan beam by a pair of collimating rings (21). After passing through the patient, X-rays are detected by an array (22) of movable detectors. Detector subarrays (23) are synchronously movable out of the X-ray plane to permit the passage of the fan beam.

Abstract: In a speech processing arrangement for synthesizing more natural sounding speech, a speech signal is partitioned into intervals. For each interval, a set of coded prediction parameter signals, pitch period and voicing signals, and a set of signals corresponding to the spectrum of the prediction error signal are produced. A replica of the speech signal is generated responsive to the coded pitch period and voicing signals as modified by the coded prediction parameter signals. The pitch period and voicing signals are shaped responsive to the prediction error spectral signals to compensate for errors in the predictive parameter signals whereby the speech replica is natural sounding.

Abstract: An electroacoustic transducer assembly adapted to filter sound waves in a digital communication system incorporates a plurality of tandemly arranged tubular members and a transducer. Each tubular member includes an apertured plate end, a tubular cavity and an open end. The open end of each tubular member is secured to the plate end of the adjacent tubular member to form a housing with a divided longitudinal passageway. The open end of the housing is secured to the transducer. Every tubular cavity is partitioned into longitudinal sections by structural elements to inhibit cross mode resonance. The apertures, cavity lengths and structural elements are dimensioned relative to the cavity cross sections to suppress passage of sound waves outside a predetermined frequency band.

Abstract: To improve the speech quality at lower bit rates within a digital communication system in which the coefficients of a frequency transform (e.g. discrete cosine transform) are adaptively encoded with adaptive quantization and adaptive bit-assignment, the adaptation is controlled by a short-term spectral estimate signal formed by combining the formant spectrum and the pitch excitation spectrum of the coefficient signals.

Abstract: A speech analyzer for recognizing an unknown utterance as one of a set of reference words is adapted to generate a feature signal set for each utterance of every reference word. At least one template signal is produced for each reference word which template signal is representative of a group of feature signal sets. Responsive to a feature signal set formed from the unknown utterance and each reference word template signal, a signal representative of the similarity between the unknown utterance and the template signal is generated. A plurality of similarity signals for each reference word is selected and a signal corresponding to the average of said selected similarity signals is formed. The average similarity signals are compared to identify the unknown utterance as the most similar reference word.

Abstract: A speech analyzer for recognizing an unknown utterance as one of a set of reference words is adapted to generate a feature signal set for each utterance of every reference word. At least one template signal is produced for each reference word which template signal is representative of a group of feature signal sets. Responsive to a feature signal set formed from the unknown utterance and each reference word template signal, a signal representative of the similarity between the unknown utterance and the template signal is generated. A plurality of similarity signals for each reference word is selected and a signal corresponding to the average of said selected similarity signals is formed. The average similarity signals are compared to identify the unknown utterance as the most similar reference word.