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354 results about "Effective frequency" patented technology

In advertising, the effective frequency is the number of times a person must be exposed to an advertising message before a response is made and before exposure is considered wasteful. The subject on effective frequency is quite controversial. Many people have their own definition on what this word means. There are also numerous studies with their own theories or models as to what the correct number is for effective frequency.

Link adapting method based on AMC-ARQ (Adaptive Modulation and Coding-Automatic Repeat-reQuest) striding layer

The invention relates to a link adapting method based on an AMC-ARQ (Adaptive Modulation and Coding-Automatic Repeat-reQuest) striding layer. The link adapting method comprises the step of designing a mapping relation of a receiving SNR (Signal to Noise Ratio) of a physical layer and MCS (Modulation Coding Scheme) by utilizing a QoS (Quality of Service) demand of a data link layer and the information of the physical layer according to a target packet error rate of the physical layer. According to an ergodic method, the optimal packet error rate of the physical layer, the maximum retransmission times of the ARQ of the data link layer and the size combination of a rearranging timer of the data link layer are searched, so that the use ratio of effective frequency spectrum is maximal. According to the link adapting method provided by the invention, the physical layer and the data link layer are comprehensively considered; the correlation influence of the parameters between the two layers is fully utilized to obtain AMC and ARQ parameters; the optimal parameter combination for maximizing the efficiency of the effective frequency spectrum is obtained; and the time delay is calculated by dividing the time delay into two parts of a queuing time delay and a transmission time delay, so that the calculation for the time delay is more accurate. According to the link adapting method provided by the invention, the selection for a modulation coding mode is relative to a channel condition and transmission times, and the redundant information transmitted at each time is fully utilized.
Owner:HUAZHONG UNIV OF SCI & TECH

Colorful blood flow imaging based on ultrasonic Doppler frequency spectrum and display method thereof

The invention discloses a colorful blood flow imaging based on an ultrasonic Doppler frequency spectrum and a display method thereof. The display method comprises the following steps: (1) selecting a sampling door which is large enough; (2) dividing the sampling door into M sub-doors; (3) calculating the frequency spectrum of a time series summed in every sub-door; (4) calculating the upper and lower envelope curves of the frequency spectrum corresponding to every sub-door, determining an effective frequency band analysis area, and calculating the average blood flow speed and a mean square error in the effective frequency band analysis area; and (5) converting speed and variance yields into colorful codes and displaying by using a preset color mapping table. According to the display method provided by the invention, a plurality of doors are utilized to obtain the flow velocity and variance distribution at different positions along the cross section of a blood vessel, therefore, the distribution of the blood flow in a spatial position can be observed better, the volume and blood flow velocity can be measured more precisely, and the colorful blood flow imaging has an important clinical meaning on the diagnosis of cardiovascular diseases.
Owner:SASET CHENGDU TECH LTD

Method for measuring thickness of coatings through ultrasonic signal spectrum filter technology in nondestructive mode

The invention provides a method for measuring thickness of coatings through the ultrasonic signal spectrum filter technology in a nondestructive mode, and belongs to the technical field of ultrasonic non-destructive testing. The method includes the steps that normalization processing is conducted on reflective sound pressure P[reflection] (x1) by ultrasonic incident sound pressure P[incidence] (x0), and then normalization sound pressure reflection coefficients R (x1-x0) of the coatings are acquired, and the R (x1-x0) is expanded to plural Fourier series through the spectrum analysis technology and divided into an independent real part function Real (f) and an independent imaginary part Imag (f); Fourier transformation is conducted on a real part function V[real] (f) in an effective frequency band acquired through windowing processing to acquire a power spectrum M (tau) of the real part function V real (f), FFT filtering bandwidths are selected according to the occurrence positions of maximum values of the power spectrum, the V[real] (f) is sequentially filtered to acquire a series of cosine functions, the periods of the cosine functions are read, propagation sound time ti of ultrasonic waves in the coatings is calculated, and then the thickness of the coatings is represented by the cooperation of longitudinal wave sound velocity of the coatings. The method is not affected by material attributes and the process environment, the problems that in a conventional ultrasonic method, aliasing occurs in time domains, and resonant frequency of the spectrum is difficult to recognize are solved, and the problem of ultrasonic thickness measurement of the multiple coatings is solved.
Owner:DALIAN UNIV OF TECH

EEG (electroencephalogram) feature extraction method

The invention discloses an EEG (electroencephalogram) feature extraction method. The EEG feature extraction method includes the steps of removing artifacts in background EEG data and EEG data to be processed to obtain effective frequencies of the background EEG data and the EEG data to be processed, and respectively dividing the effective frequencies of the background EEG data and the EEG data to be processed into a plurality of data segments; extracting time-frequency feature and morphological feature of each data segment to obtain time-frequency feature value and morphological feature value of each data segment; calculating to obtain a frequency distribution function of the feature values according to the time-frequency feature value and the morphological feature value of each data segment of the background EEG data; obtaining probabilities of occurrence of the time-frequency feature value and the morphological feature value of each data segment of the EEG data to be processed according to the frequency distribution functions of the background EEG data; and calculating to obtain IMF-VoE (intrinsic mode functions and upper and lower envelopes) feature values according to the probabilities of the feature values. Change features of EEG signals can be quickly and effectively recognized by the IMF-VoE feature values to monitor brain statuses.
Owner:浙江浙大西投脑机智能科技有限公司

Electrocardiograph detection method based on quantum simple recursion neural network

The invention relates to an intelligent method for testing cardiograms by basing on quanta a simple recursion neural network, which comprises the steps that: the cardiac electric signals are sent to a self-adaptation power frequency disturbance-restriction module for restricting the disturbance of the power frequency; the two output cardiac electric signals in the previous step are sent to a blind baseline drift disturbance-restriction module so as to remove the breath baseline drift disturbance; the output cardiac electric signals in the second step are sent to the quanta simple recursion neural network for carrying out cardiac electric intellectual test and output. The self-adaptation power frequency disturbance-restriction module comprises two same groups of self-adaptation power frequency disturbance-restriction units, and carries out power frequency disturbance-restriction on the two collected groups of cardiac electric signals simultaneously and respectively. The self-adaptation power frequency disturbance-restriction module can automatically restrict power frequency disturbance by adopting the cardiac electric power frequency disturbance-restriction method basing on QR decomposing recursive least squares (RLS) algorithm self-adaptation trap technology. The invention can not only realize cardiac electric intellectualization test, but also remove the power frequency and the breath baseline drift disturbance in the effective frequency band of cardiac electric signals, and solve the difficulty that digital filtration method eliminates the disturbance of aliasing in spectrum.
Owner:CIVIL AVIATION UNIV OF CHINA

Fault diagnosis method of motor bearing based on time-frequency domain statistical characteristic

The invention discloses a fault diagnosis method of a motor bearing based on a time-frequency domain statistical characteristic. The fault diagnosis method comprises the following steps that: speed pulse signals and vibration signals of the motor bearing in T time interval are collected simultaneously, and a frequency conversion curve f is calculated according to the speed pulse signals; the vibration signals at a stationary speed are intercepted according to the frequency conversion curve and are sectioned; health indicators of the vibration signals in all segments are calculated according toa formula of the health indicators, a fault degree grade of each segment is obtained by comparing the health indicators with a fault threshold table, and the fault grade with the highest fault degreegrades counted is the fault grade of the motor bearing; Hilbert envelope spectrums of the vibration signals in all segments are calculated, effective frequencies of all envelope spectrums are determined according to a calculation method of the effective frequencies, the most frequent occurrence frequency of the effective frequencies counted is a fault frequency, and then a fault position of the bearing is determined. The overall fault degree and the fault position of the motor bearing are accurately obtained by counting the fault grade of the vibration signals and the effective frequencies ofthe envelope spectrums in a plurality of time intervals.
Owner:XI AN JIAOTONG UNIV

An off-resonance type wheel-type generator based on a cantilever beam piezoelectric vibrator

The invention relates to an off-resonance type wheel-type generator based on a cantilever beam piezoelectric vibrator, and belongs to the field of piezoelectric power generating. A rotary disc slide sink cavity is communicated with a central hole on the other side and communicated with an annular cavity through a guide hole; a cantilever shaft sleeved in the center hole is connected with a side plate installed on a side of the sink cavity; the side plate is provided with an annular cavity and a guide hole; extrusion balls are filled in the guide holes of the rotary disc and the side plate; a cantilever of a metal substrate pressed by the end cap in the annular cavities of the rotary disc and the side plate and a bonded piezoelectric wafer constitute a piezoelectric vibrator; an excitation disc is filled in a slide formed the slide sink cavity and the cantilever shaft; balls are embedded in the inner rim and the outer rim of the excitation disc; and a lift inclined plane, a convex surface, return inclined surface and a concave surface on the two sides of the excitation disc form an excitation unit. The advantages and characteristics of the off-resonance type wheel-type generator are that no fixed support is needed and no electromagnetic interference exists; the piezoelectric oscillator structure is reasonable; off-resonance power generation is realized and the deformation of the radius is determined by a limit surface; stress points are the same and only bear compressive stress, so that the electric power generation is large; the reliability is high; an effective frequency band width is large; and the off-resonance type wheel-type generator is especially suitable for a low rotating speed environment.
Owner:ZHEJIANG NORMAL UNIVERSITY

Coherent value obtaining method and system of earthquake data amplitude spectrum

The invention discloses a coherent value obtaining method and system of an earthquake data amplitude spectrum. The method comprises: step 1, obtaining a three-dimensional post-stack earthquake data body; step 2, calculating an effective frequency range for obtaining an amplitude spectrum; step 3, selecting a certain sampling point in the three-dimensional post-stack earthquake data body, and setting a slave data body which centers on a certain sampling point and includes a J-channel earthquake record; step 4,superposeing a window function on the J-channel earthquake record in the slave data body, and respectively performing Fourier transformation to obtain the amplitude spectrum of the J-channel earthquake record; step 5, obtaining and using the amplitude spectrum of the effective frequency range in the amplitude spectrum of the J-channel earthquake record to construct a J-dimensional covariance matrix, and calculating the characteristic roots of the J-dimensional covariance matrix, wherein the ratio of the maximum characteristic root in the characteristic roots to the sum of all the characteristic roots is a coherent value of a certain sampling point; and step 6, repeating step 3 to step 5, traversing each sampling point in the three-dimensional post-stack earthquake data body, and obtaining and recording the coherent value of each sampling point.
Owner:PETROCHINA CO LTD

Seismic phase and frequency correction method based on complex seismic trace decomposition and reconstruction

The invention relates to a seismic phase and frequency correction method based on complex seismic trace decomposition and reconstruction. The method includes the following steps that first, according to an effective frequency band range recorded in known earthquakes, a subwave base traversing the effective frequency band range and a non-stationary convolution model are established; second, the subwave base is converted into complex numbers through Hilbert conversion, and a complex subwave base is established; third, the non-stationary convolution model is changed into the complex number form through the complex subwave base, complex reflection coefficients (please see the formula in the specification) are resolved through linear operation and sparse inversion constrained by L1 norm, the complex reflection coefficients (please see the formula in the specification) are substituted into the non-stationary convolution model in the complex number form, the real number part of the complex reflection coefficients is obtained, reconstruction on the seismic section is achieved, and according to the frequency of the seismic subwaves in the complex subwave base changed before reconstruction and obtained phase information in the complex reflection coefficients, frequency correction, phase correction and synchronous correction of frequency and phases on the original earthquake records are achieved. The method can be widely applied in the oil exploration process.
Owner:CHINA NAT OFFSHORE OIL CORP +1

Audio signal processing device

InactiveCN103347229ASolve the problem that data transmission cannot be performed through existing methodsEffectively filter out noiseTransducer circuitsTransfer procedureData transmission
Provided in the invention is an audio signal processing device that comprises a first device and a second device. The first device includes a first loudspeaker outputting a first audio signal. The second device includes a first microphone and a first filter; the first microphone receives the first audio signal and carries out sampling on the first audio signal to generate first audio data; and the first filter filters frequency points of the first audio data to obtain second audio data. According to the invention, the audio signal is used to carry out data transmission, thereby solving a problem that an audio device with an audio interface can not carry out data transmission by the existing way. During the transmission process, the amplitude of the audio signal is attenuated with increasing of the distance and the frequency of the audio signal is not changed with the distance changing. Therefore, corresponding frequency points of the audio data generated by the microphone are filtered and noises are filtered, thereby obtaining frame head and frame tail information of effective information; and a signal frequency of an effective frequency point is responded according to the information so as to obtain effective information, thereby ensuring accuracy of signal transmission.
Owner:TENDYRON CORP
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