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106 results about "Orthogonal wavelet" patented technology

An orthogonal wavelet is a wavelet whose associated wavelet transform is orthogonal. That is, the inverse wavelet transform is the adjoint of the wavelet transform. If this condition is weakened one may end up with biorthogonal wavelets.

Extraction method for early failure sensitive characteristics based on ensemble empirical mode decomposition (EEMD) and wavelet packet transform

InactiveCN103091096AGuaranteed Adaptive Accurate PartitioningAdaptive Precise Partition PreciseMachine gearing/transmission testingMachine bearings testingNODALDecomposition
The invention relates to an extraction method for early failure sensitive characteristics based on ensemble empirical mode decomposition (EEMD) and wavelet packet transform. The extraction method for the early failure sensitive characteristics based on the EEMD and the wavelet packet transform includes the following steps: (1), collected original vibration signals of mechanical and electrical equipment are decomposed according to the EEMD, white noise is added, and intrinsic mode function (IMF) components are obtained through decomposition; (2), the sensitive IMF components closely related to failure are chosen, and other irrelative IMF components are ignored; (3), the sensitive IMF components chosen through step (2) are decomposed in an orthogonal wavelet packet mode, and a wavelet coefficient of each node is obtained; and (4), envelopes are extracted from the obtained wavelet packet coefficients by adoption of the Hilbert transform and the Fourier transform, power spectrums are calculated, the power spectrum corresponding to each wavelet packet coefficient is obtained and serves as the early failure sensitive characteristic , and the sensitive characteristics are automatically obtained. Self-adapting signals can be decomposed, the sensitive characteristics can be convenient to obtain automatically, diagnosis precision and speed are improved, and a mechanical and electrical system can be diagnosed quickly, accurately and stably. The extraction method for the early failure sensitive characteristics based on the EEMD and the wavelet packet transform can be applied to the field of mechanical and electrical equipment failure diagnosis.
Owner:BEIJING INFORMATION SCI & TECH UNIV

Particle swarm optimization based orthogonal wavelet blind equalization method

The invention discloses a particle swarm optimization based orthogonal wavelet blind equalization method. The method comprises the following steps of: allowing a transmitted signal a(k) to pass through a pulse response channel h(k) to acquire a channel output signal x(k); acquiring an orthogonal wavelet transformation (WT) input signal y(k) through channel noise n(k) and x(k); performing WT on the input signal y(k) to acquire an output signal R(k); taking the input signal y(k) as input of a particle swarm optimization (PSO) algorithm and randomly initializing a group of weight vectors, wherein each particle corresponds to each group of weight vectors one to one; determining a fitness function of PSO through a cost function of an orthogonal wavelet transformation-constant module algorithm (WT-CMA) blind equalization method; when a fitness value is the maximum, finding out an optimal position vector in the group and taking the optimal position vector as an initialization weight vector W(k) of the WT-CMA; and acquiring an equalizer output signal z(k) from the output signal R(k) and initialization weight vector W(k). In the method, the optimal equalizer initialization weight vector is sought through PSO, and the autocorrelation of the signal is reduced by WT. Compared with WT-CMA, the method has higher convergence rate and lower steady-state error.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Leakage locating method combining self-adapting threshold value leak detection and multi-dimension fast delay time search

A leak positioning method combining self-adapting threshold value leak detection and multi-scale rapid time delay search belongs to the malfunction diagnosis technology field of oil (gap) pipeline, wherein pressure data at both ends of the pipeline and standard error of re-constructing signal difference value of the data based on orthogonal wavelet transformation de-noising process multiplying coefficient as threshold values at both ends. If average values before or after catastrophe point when the pressure at both ends reduces exceed the threshold value, judging that there is leak and positioning: calculating approximate wavelet transformation coefficient of pressure data at both ends, initializing searching interval, calculating a signal time delay value corresponding to approximate wavelet transformation coefficient in the searching interval from maximal scale N; converting the time delay value under scale N to that under N-1 by geometric proportion relation; updating the searching interval, repeating above processes until the scale is 0 and positioning based on the time delay value. The invention is capable of reducing rate of false report and rate of missing report effectively, reducing time delay estimated calculated amount, which is beneficial to accomplish arithmetic online.
Owner:TSINGHUA UNIV

Modeling method of symmetrical type plate spring virtual model enhancing haptic feedback

InactiveCN101976298ASimple calculationReal-time deformation simulation is accurate and fastSpecial data processing applicationsOrthogonal waveletPull force
The invention discloses a modeling method of a symmetrical type plate spring virtual model enhancing haptic feedback, which is characterized by comprising the following steps of: only feeding back and outputting 1/f noise signals based on orthogonal wavelet bases before a virtual agent collides with a virtual flexible body; feeding back and outputting signals obtained by overlying the 1/f noise signals fitting to the response law of human bodies on irritation and the haptic information of the real-time deformation simulation of the flexible body, which is calculated by adopting the symmetrical type plate spring virtual model and responded under the action of pulling force, together in an interactive process, wherein the overlying of the deformation amount sum of each layer of symmetrical type single-plate spring of the symmetrical type plate spring virtual model enhancing the haptic feedback is externally equivalent to the deformation of the surface of the flexible body, and the sum of pulling force consumed when each layer of the symmetrical type single-plate spring is stretched is equivalent to given virtual contact pulling force. The modeling method can realize the real-time deformation simulation of the flexible body, has real haptic feeling and vivid deformation effect and meets the requirements of a virtual reality system on virtual surgery simulation.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Bridge deformation multi-frequency dynamic analysis method based on combined differential GNSS

The invention discloses a bridge deformation multi-frequency dynamic analysis method based on a combined differential GNSS and relates to the field of bridge deformation monitoring technologies. According to the method, an orthogonal wavelet fast decomposition algorithm is utilized to process a bridge GNSS monitoring signal, an analysis signal is separated on different bands, and multi-scale analysis is performed on a deformation signal; a high-frequency signal is utilized to analyze wink movement of a bridge under the action of external forces such as wind power, vehicle passage or other seismic disasters, and a de-noised low-frequency signal is utilized to analyze a deformation track of a bridge dynamic deformation body; and last, the analysis result is utilized to further analyze the bridge deformation trend. Therefore, by analyzing the characteristics of different frequencies in the GNSS monitoring signal, a static response and a dynamic response of the bridge can be effectively decomposed, the problem that the reason for bridge deformation caused by a bridge three-dimensional displacement change cannot be judged through an existing bridge monitoring system is solved, subsequent monitoring analysis is effectively guaranteed, and a good guarantee is provided for safety monitoring of the bridge.
Owner:CHINA ACAD OF TRANSPORTATION SCI +1

Self-adapting multi-dimension veins image segmenting method based on wavelet and average value wander

The invention discloses a self-adaptive multi-scale texture image segmentation method based on wavelet and mean shift, and relates to the image processing technical field. The invention aims to solve the contradiction between the region consistency of a texture image and the edge accuracy of adjacent regions in the regular method to achieve the effect that the image is effectively segmented under the condition of failing to obtain the priori knowledge. The realization process of the method is that: based on the orthogonal wavelet transformation, mean shift clustering without supervision is used to realize the segmentation of the feature of a wavelet transform coefficient on different scales; through the information transmission of the features among different scales, self-adaptive different regions as the image select appropriate segmentation scales, namely the interior of a texture region uses a coarse scale feature, the boundaries of different texture regions use a finer scale feature, thus the edge of the image is located more accurately while the region consistency is assured until the final segmentation result is obtained. The invention can be used to solve the texture image segmentation issue without any priori knowledge.
Owner:XIDIAN UNIV

Orthogonal wavelet multi-mode blind equalization method based on chaos optimization

The invention discloses a chaos-optimized orthogonal wavelet multi-mode blind equalization method (CO-WT-MMA). It includes the following steps: pass the transmitted signal a(k) through the impulse response channel h(k) to obtain the channel output vector x(k); use the channel noise n(k) and the channel output vector x(k) to obtain the orthogonal wavelet transformer ( WT) input signal y(k)=n(k)+x(k); After the real part and imaginary part of y(k) are subjected to orthogonal wavelet transform and chaos initialization respectively, and then through the corresponding real part and imaginary part The partial equalizer is output to the complex adder to get the output z(k). On the basis of the multi-mode blind equalization method (MMA), the multi-mode blind equalization method (WT-MMA) based on the orthogonal wavelet transform obtained after the normalized orthogonal wavelet transform accelerates the convergence speed, and at the same time utilizes The ergodicity of the chaotic variable disturbs the current point of the weight vector, and the time-varying parameters are used to gradually reduce the disturbance amplitude during the search process, so that the weight vector reaches the global optimal value. The underwater acoustic channel simulation results show that, compared with MMA and WT-MMA, the CO-WT-MMA of the present invention has faster convergence speed and smaller steady-state mean square error.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Orthogonal wavelet transform constant modulus blind equalization algorithm based on optimization of DAN genetic algorithm

The invention discloses an orthogonal wavelet transform constant modulus blind equalization algorithm based on optimization of the DAN genetic algorithm (DNA-GA-WTCMA). According to the algorithm, the DNA genetic algorithm is combined with the WTCMA and the advantages of the WT-CMA and the advantages of the DNA genetic algorithm are thoroughly utilized. According to the orthogonal wavelet transform constant modulus blind equalization algorithm, a weight vector of the blind equalization algorithm is shown according to a coding method based on a DNA nucleotide chain and interlace operation and mutation operation are conducted on the coded DNA chain to find an optimal individual in a DAN group, the decoded optimal individual serves as an optimal initial weight vector of a blind equalization device, and the shortages that the WTCMA is low in convergence rate, large in mean square error and prone to getting into local minimum are overcome. Compared with the WTCMA and the GA-WTCMA, the DNA-GA-WTCMA is the highest in convergence rate, the smallest in mean square error, globally optimal in performance and high in practical value in the communication technical field.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Orthogonal wavelet constant modulus blind equalization method based on IWPA (Improved Wolf Pack optimization Algorithm)

The invention discloses an orthogonal wavelet constant modulus blind equalization method based on an IWPA (Improved Wolf Pack optimization Algorithm). According to the invention, A CM (Complex Method) with high local searching capacity is embedded into a WPA with high global optimizing capacity; an update mechanism of a wolf pack is improved to obtain an excellent IWPA; the new method promotes optimizing capacity of the WPA; a reciprocal of a cost function in the constant modulus blind equalization method CMA is used as a fitness function of the IWPA; an input signal of the CMA is used as an input of the IWPA; a leader wolf position captured by utilizing the IWPA is used as an initial weight vector of the CMA; then signal correlation is reduced by a wavelet; signals are output in an equalizing mode by the CMA; and an excellent equalizing effect can be obtained. Compared with the prior art, the orthogonal wavelet constant modulus blind equalization method has the advantages that correlations between the signals and between the signals and noise can be reduced; an algorithm convergence speed is improved; a steady state error is reduced; balancing quality is improved; and the orthogonal wavelet constant modulus blind equalization method has a certain practical value.
Owner:HUAINAN UNITED UNIVERSITY

Orthogonal wavelet blind equalization method based on immune clone particle swarm optimization

The invention discloses an orthogonal wavelet blind equalization method based on immune clone particle swarm optimization. The method comprises the steps of: by regarding a particle swarm as an immune system, randomly initializing particles in a search space, namely, initializing the speed and the positions of antibodies, wherein the position vectors of the particles are taken as the weight vectors of an equalizer and the number of the weight vectors is taken as the scale of the particles; randomly generating an initial population, wherein the position vector with a maximal fitness value (that is optimal solution) is used as an antigen, the particles are used as the antibodies, the affinity degree is used for presenting the approaching degree of the antibodies and the antigen, and a fitness degree function of the particle swarm optimization is selected as the affinity degree of the antibodies; carrying out immune clone operation on the antibodies with higher fitness degree through iteration to continuously generate a new-generation antibody population; carrying out the immune clone operation on the selected optimal solution in each iteration; selecting the optimal position vector (that is the generated maximal value of the corresponding fitness degree function) of the particles after the iteration ends; and iterating by taking the position vector as an initialization weight vector of the equalizer.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Simulation annealing and fruit fly hybrid optimization wavelet generalized discrete multi-modulus blind equalization method

The invention discloses a simulation annealing and fruit fly hybrid optimization wavelet generalized discrete multi-module blind equalization method. The method comprises initializing location vectors of fruit flies in a swarm of fruit flies to serve as the decision variable of the simulation annealing method and the fruit fly hybrid optimization method, taking an input signal of an orthogonal wavelet transformer as the input of the hybrid optimization method, determining a smell concentration function of the fruit flies by a cost function of the generalized discrete multi-modulus blind equalization method, performing simulation annealing operation on the optimal location vector of the swarm of the fruit flies obtained through the fruit fly optimization method, obtaining the global optimal location vector, which does not fall into a local minimum, of the swarm of the fruit flies, and taking the location vector as the initialization weight vector of the wavelet generalized discrete multi-modulus blind equalization method. The method, while processing high-order orthogonal amplitude modulation signals, is rapid in convergence, small in steady state error, overcomes a defect of falling into the local optimum, and has strong practicality.
Owner:南京鸿晟科技有限公司

Frequency-domain self-adaptation wavelet multi-mode blind equalization method for immune artificial shoal optimization

The invention discloses a frequency-domain self-adaptation wavelet multi-mode blind equalization method for immune artificial shoal optimization. The frequency-domain self-adaptation wavelet multi-mode blind equalization method for the immune artificial shoal optimization comprises the following steps that an immune artificial shoal is a mixed group of an artificial shoal and an immune system antibody shoal, position vectors of the artificial shoal and antibody vectors of an immune system of a set of immune artificial shoal are initialized in a random mode, the position vectors and the antibody vectors serve as decision variables of an immune artificial shoal method, input signals of an orthogonal wavelet converter serve as input signals of the immune artificial shoal method, a fitness function of the immune artificial shoal is determined by a cost function of the frequency-domain self-adaptation wavelet multi-mode blind equalization method, and initialization weight vectors of the frequency-domain self-adaptation wavelet multi-mode blind equalization method are determined by an immune artificial shoal optimization method. The frequency-domain self-adaptation wavelet multi-mode blind equalization method for the immune artificial shoal optimization is high in rate of convergence, low in steady-state error, low in complexity and good in practicability when the frequency-domain self-adaptation wavelet multi-mode blind equalization method for the immune artificial shoal optimization is used for processing high-order QAM signals.
Owner:NANJING UNIV OF INFORMATION SCI & TECH

Data compression and decompression method on basis of orthogonal wavelet packet transform and rotating door algorithm

The invention discloses a two-stage data compression and decompression method on the basis of orthogonal wavelet packet transformation and a rotating door algorithm. Data compression comprises the following steps of: (1) carrying out orthogonal wavelet packet transformation on original data to obtain a wavelet packet coefficient; (2) carrying out threshold processing on the wavelet packet coefficient obtained in the step (1); and (3) carrying out secondary compression on the wavelet packet coefficient subjected to threshold processing by adopting the rotating door algorithm. Compressed data is stored into a historical database or a disk. Decompression on the compressed data comprises the following steps of: (4) carrying out linear interpolation on the compressed data and recovering to obtain primary compressed data; and (5) carrying out wavelet packet reconstitution on the primary compressed data to obtain the original data. The invention solves the problem of difficulty in compressing a nonstationary analog signal in a large-scale real-time database and provides the data compression and decompression method which is simple to implement, has a high data compression ratio and has an obvious compressing effect on the nonstationary analog signal.
Owner:GUODIAN NANJING AUTOMATION
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