161 results about "Phase domain" patented technology

The invention relates to a modal parameter identification method based on response signal time-frequency joint distribution characteristics. According to the modal parameter identification method based on the response signal time-frequency joint distribution characteristics, signal analysis and structural modal parameter identification are carried out directly through a structural vibration response. The modal parameter identification method based on the response signal time-frequency joint distribution characteristics comprises the steps of firstly carrying out complex wavelet continuous transformation on a structural response signal, obtaining energy distribution characteristics of various wavelet transformation domains (a real domain, a virtual domain, a modal domain and a phase domain), obtaining a time average wavelet energy spectrum through a wavelet transformation coefficient, therefore carrying out quantification on selection of model orders and the scale corresponding to each order modality, on the basis, obtaining the optimum scale required by parameter identification, achieving pre-identification of modal frequency through the corresponding relation of the scale and the frequency, finally extracting a wavelet transformation coefficient slice at the specific scale, carrying out linear fitting through an amplitude value and a phase component, and achieving structural identification of inherent frequency and a damping ratio. As simulation and experiment results show, even if an external incentive function is not included, accurate identification of structural modal parameters can be achieved through the modal parameter identification method based on the response signal time-frequency joint distribution characteristics.

The invention relates to a preparation method of a nylon-6-based polyesteramide fiber. The method comprises the steps of carrying out melt spinning on a nylon-6-based polyesteramide polymer to obtainthe nylon-6-based polyesteramide fiber. A preparation method of the nylon-6-based polyesteramide polymer comprises the steps of mixing nylon-6 prepolymer ester with a polyester prepolymer and then carrying out an ester exchange reaction to obtain the nylon-6-based polyesteramide polymer. The nylon-6 prepolymer ester is prepared by firstly synthesizing a dibasic-acid-terminated nylon-6 prepolymer and then adding dihydric alcohol to enable dihydric alcohol to react with carboxyl of terminal groups. According to the preparation method of the nylon-6-based polyesteramide fiber, the nylon-6-based polyesteramide polymer is obtained through a copolymerization approach, so that the uniformity of nylon-6 and polyester blocks is improved, and the phase domain is controllable; polyesteramide slices containing polyester chain segments at different ratios can be obtained by changing the addition quantity of the polyester prepolymer, so that the sequence structure is controllable, and the polymerization process is flexible. The prepared fiber has high spinnability and stiffness and can be applied to the fields of clothing, home textiles, automobile interior decoration and the like.

The invention discloses a multi-target learning far field speech recognition method based on amplitude and phase information, which comprises the following steps of: S1, preparing input data; S2, extracting an amplitude characteristic and various phase characteristics; and S3, constructing a multi-task deep neural network, inputting the extracted amplitude characteristic and phase characteristicsinto the neural network to train, and outputting an enhanced speech and the enhanced characteristics. The enhanced speech is utilized to carry out SRMR evaluation, and the enhanced characteristics areutilized to carry out speech recognition. The method utilizing multi-target learning, which is disclosed by the invention, simultaneously enhances the speech and the characteristics, and compared toan existing method, in consideration of a bad effect of characteristics of a group delay system (MGDCC) under a reverberation speech, adds another phase characteristic, i.e., channel information (PBSFVT) of a source separation method based on a phase domain, to make up the defect of the MGDCC, so as to improve speech recognition accuracy.

Provided is an approach for active control of cross currents flowing among multiple paralleled converters. Control of cross currents is achieved by using at least one proportional-integral (PI) controller and at least one resonant controller to target several selected dominant harmonics with infinite gains to ensure elimination of targeted harmonic cross currents in steady state. The cross currents are decomposed by into (1) common mode and differential mode components or (2) current phase domain components and each component is suppressed to a value approximately near zero using the controller. Also provided is a device comprises instructions, that, when executed by a processor, cause the processor to perform operations, which regulate and suppress cross current within a power system.