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333 results about "Cepstrum" patented technology

A cepstrum (/ˈkɛpstrʌm, ˈsɛp-, -strəm/) is the result of taking the inverse Fourier transform (IFT) of the logarithm of the estimated spectrum of a signal. It may be pronounced in the two ways given, the second having the advantage of avoiding confusion with "kepstrum", which also exists (see below). There is a complex cepstrum, a real cepstrum, a power cepstrum, and a phase cepstrum. The power cepstrum in particular has applications in the analysis of human speech.

Speaker verification for authorizing updates to user subscription service received by internet service provider (ISP) using an intelligent peripheral (IP) in an advanced intelligent network (AIN)

A method for controlling subscription services delivered to a user by an Internet Service Provider (ISP) coupled to an Automated Intelligent Network (AIN) telephone system with at least one central office switching system. An intelligent peripheral subsystem is connected to the central office switching system, via a call connection channel. The intelligent peripheral subsystem providing at least one auxiliary call processing capability via the call connection channel and provides a telephony speaker authentication method for selectively authorizing updates to user subscription services types provided by the ISP, wherein each of the subscription services types include one or more service options. The method for controlling subscription services including: a) prompting for a voice response; b) authenticating a user's voice response pattern by performing a speaker-dependent cepstrum matching algorithm with previously stored samples of the user's voice response, and if the user's voice response pattern is positively authenticated with previously stored samples, then performing the steps of: c) presenting a menu of user subscription types, each with available AIN service options; and d) responding to a user selection of at least one user subscription types, each with service option, by activating a service option selected by the user, wherein the service option is governed by said ISP by regulating one or more Uniform Resource Locator (URL) addresses received by a user subscriber device from said ISP over a telecommunication line.
Owner:IBM CORP

Fundamental frequency identification method for detecting cord force of cable-stayed bridge

The invention discloses an identification method of fundamental frequency for detection of the force of the cable of a stayed-cable bridge, which gets a first fundamental frequency by an autopower spectrum module, a second fundamental frequency by a cepstrum module, and then determines whether the quotient of the following two values is less than or equal to the set threshold: 1. the absolute value of the difference of the first fundamental frequency and the second fundamental frequency; 2. a half of the sum of the first fundamental frequency and the second fundamental frequency. In this way, whether the fundamental frequency of the pull cable is a half of the first fundamental frequency and the second fundamental frequency is determined. By adopting the method, the accuracy and the precision of the fundamental frequencies got are significantly improved. In addition, as the vibration acceleration response time interval signal got by an acceleration sensor passes through a signal conditioning module for filtration and smooth processing firstly, the environmental noise in the vibration acceleration response time interval signal is effectively suppressed; the antijamming capability of the stayed-cable bridge is improved so that the fundamental frequency is identified more clearly and accurately.
Owner:NINGBO UNIV

A Robust Speech Feature Extraction Method Based on Sparse Decomposition and Reconstruction

The invention discloses a robust speech characteristic extraction method based on sparse decomposition and reconfiguration, relating to a robust speech characteristic extraction method with sparse decomposition and reconfiguration. The robust speech characteristic extraction method solves the problems that 1, the selection of an atomic dictionary has higher the time complexity and is difficult tomeet the sparsity after signal projection; 2, the sparse decomposition of signals has less consideration for time relativity of speech signals and noise signals; and 3, the signal reconfiguration ignores the prior probability of atoms and mutual transformation of all the atoms. The robust speech characteristic extraction method comprises the following detailed steps of: step 1, preprocessing; step 2, conducting discrete Fourier transform and solving a power spectrum; step 3, training and storing the atom dictionary; step 4, conducting sparse decomposition; step 5, reconfiguring the speech spectrum; step 6, adding a Mel triangular filter and taking the logarithm; and step 7, obtaining sparse splicing of Mel cepstrum coefficients and a Mel cepstrum to form the robust characteristic. The robust speech characteristic extraction method is used for the fields of multimedia information processing.
Owner:哈尔滨工业大学高新技术开发总公司

Rolling bearing fault feature extraction method based on independent component analysis and cepstrum theory

The invention provides a rolling bearing fault feature extraction method based on an independent component analysis and cepstrum theory. The rolling bearing fault feature extraction method comprises the steps of acquiring a vibration acceleration testing signal of a rolling bearing by using an acceleration sensor; decoupling and separating the vibration acceleration testing signal by using FastICA based on negentropy maximization; selecting a separated signal capable of representing fault feather information to the maximum extent; carrying out cepstrum analysis on the selected separated signal, and drawing a cepstrum chart; observing whether the cepstrum chart has a fault feature frequency or an obvious peak value at a frequency multiplication position, and furthermore, judging whether the rolling bearing has a fault. By using the rolling bearing fault feature extraction method, the feature information of a fault signal of the rolling bearing can be effectively recognized from a complex sideband signal, a periodical fault component in a sideband can be conveniently extracted, the fault information is remarkably enhanced, the fault diagnosis precision is greatly improved, the fault diagnosis time period is shortened, and the spectral analysis difficulty is simplified; in addition, the rolling bearing fault feature extraction method is easy to realize and good in real-time property.
Owner:HARBIN ENG UNIV

Isolated word speech recognition method based on HRSF and improved DTW algorithm

The invention discloses an isolated word speech recognition method based on an HRSF (Half Raised Sine Function) and an improved DTW (Dynamic Time Warping) algorithm. The isolated word speech recognition method comprises the following steps that (1), a received analog voice signal is preprocessed; preprocessing comprises pre-filtering, sampling, quantification, pre-emphasis, windowing, short-time energy analysis, short-time average zero crossing rate analysis and end-point detection; (2), a power spectrum X(n) of a frame signal is obtained by FFT (Fast Fourier Transform) and is converted into a power spectrum under a Mel frequency; an MFCC (Mel Frequency Cepstrum Coefficient) parameter is calculated; the calculated MFCC parameter is subjected to HRSF cepstrum raising after a first order difference and a second order difference are calculated; and (3), the improved DTW algorithm is adopted to match test templates with reference templates; and the reference template with the maximum matching score serves as an identification result. According to the isolated word speech recognition method, the identification of a single Chinese character is achieved through the improved DTW algorithm, and the identification rate and the identification speed of the single Chinese character are increased.
Owner:SOUTH CHINA NORMAL UNIVERSITY +1

High-tension transmission line single-ended traveling wave fault distance detection method combined with time-frequency characteristics

The invention discloses a high-tension transmission line single-ended traveling wave fault distance detection method combined with time-frequency characteristics. According to the method, time of reciprocating propagation between an end point and a fault point and inherent frequency corresponding to the time are fully used, wherein the end point and the fault point are simultaneously obtained in a cepstrum analysis. The advantages of a traveling wave method and the advantages of a traveling wave inherent-frequency distance detection method are centralized, and therefore the problems that in single-ended traveling wave fault location, wave velocity is difficult to calculate, propagation time of a small phase angle is difficult to seek, due to the fact that only the traveling wave inherent-frequency distance method is used, the frequency is not easy to extract, and in the calculation, an initial phase angle of a bus end reflection and an initial phase angle of fault point reflection need to be considered are solved. Meanwhile, due to the fact that other interference signals are irrelevant with traveling wave signals, the high-tension transmission line single-ended traveling wave fault distance detection method combined with the time-frequency characteristics has the advantages of being high in anti-interference capacity, easy to operate, high in distance detection accuracy and very suitable for distance detection on site.
Owner:SOUTHEAST UNIV

Audio-reverberation inhibiting device and inhibiting method thereof

ActiveCN103440869AImplement reverberation suppressionImprove auditory perception qualitySpeech analysisSound producing devicesComputation complexitySpectral subtraction
The invention discloses an audio-reverberation inhibiting device and an inhibiting method thereof. The device includes a reverberation-time blind estimation module, a later-period reverberation power spectrum estimation module, a spectral-subtraction module and a complex-cepstrum-domain filtering module. A reverberation voice estimates a reverberation time through the reverberation-time blind estimation module. The later-period reverberation power spectrum estimation module establishes a reverberation statistical model through the estimated reverberation time and carries out analysis processing on the reverberation voice so that a later-period reverberation power spectrum is obtained. The spectral-subtraction module includes a gain function structure and a spectral-subtraction implementation module and a spectral-subtraction gain function is constructed firstly through use of a reverberation-voice power spectrum and a later-period reverberation power spectrum. Then the spectral-subtraction gain function and the reverberation voice are input into the spectral-subtraction implementation module so that an earlier-period voice is obtained. Finally, the earlier-period voice is input into the complex-cepstrum-domain filtering module so that a reverberation-removed voice is obtained. The audio-reverberation inhibiting device and the inhibiting method thereof is low in calculation complexity, convenient to handle in a real-time manner and capable of inhibiting audio reverberation obviously and improving voice quality efficiently.
Owner:DALIAN UNIV OF TECH

Bi-ear time delay estimating method based on frequency division and improved generalized cross correlation

The invention provides a bi-ear time delay estimating method based on frequency division and improved generalized cross correlation in reverberation environment, and relates to the field of sound source positioning. A Gammatone filter is used to effectively simulate characteristics of a basal membrane of a human ear, voice signals are subjected to frequency division processing, and two-ear cross-correlation delay is estimated under a reverberation environment. Compared with a generalized cross correlation delay estimating method, the method can estimate time delay more accurately. The sound source positioning system has better robustness. A Gammatone filter is used to conduct frequency dividing processing for bi-ear signals, and each sub-band signal is subjected to inverse transformation to a time domain after reverberation processing of cepstrum and pre-filtering. Each sub-band signal of left and right ears are subjected to generalized cross correlation operation, an improved phase transformation weight function is employed in a generalized cross correlation algorithm to obtain cross correlation value of each sub-band for summing operation, and the bi-ear time difference corresponding to maximal cross correlation value is obtained.
Owner:CHONGQING UNIV OF POSTS & TELECOMM
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