Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection ...Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection is proposed.Firstly,texture features of five scales and eight directions in the face region are extracted by Gabor wavelet transform.The statistical histogram is introduced to encode and fuse the directional index with the largest feature value on Gabor scales.Secondly,a new hybrid feature selection algorithm chaotic improved atom search optimisation with simulated annealing(CIASO-SA)is presented,which is based on an improved atomic search algorithm and the simulated annealing algorithm.Besides,the CIASO-SA algorithm introduces a chaos mechanism during atomic initialisation,significantly improving the convergence speed and accuracy of the algorithm.Finally,a support vector machine(SVM)is used to get classification results of the age group.To verify the performance of the proposed algorithm,face images with three resolutions in the Adience dataset are tested.Using the Gabor real part fusion feature at 48�48 resolution,the average accuracy and 1-off accuracy of age classification exhibit a maximum of 60.4%and 85.9%,respectively.Obtained results prove the superiority of the proposed algorithm over the state-of-the-art methods,which is of great referential value for application to the mobile terminals.展开更多
The main part of oil-immersed power equipment is oil-paper insulation.At lower ambient temperatures,transformer oil will become viscous.As a result,compared to those at room temperature or operating temperature,the fr...The main part of oil-immersed power equipment is oil-paper insulation.At lower ambient temperatures,transformer oil will become viscous.As a result,compared to those at room temperature or operating temperature,the frequency domain dielectric properties of oil-paper insulation at low temperatures are drastically different.For evaluating the insulation condition of electrical equipment,it is essential to accurately determine their dielectric properties.This paper described the FDS test,the DC conductivity test,and the transformer oil viscosity test,which was carried out in a laboratory environment for different ageing of oil-immersed pressboard and transformer oil at 233–373 K.The ef-fects of temperature on the dielectric properties at the competing mechanisms of polarisation and conductivity loss were clarified based on variations of the FDS curves.Considering the viscosity change of ageing transformer oil at low temperatures,the Arrhenius and VFT viscosity equations were used to achieve a fitting calculation in the different temperature zones.Based on the molecular/ion transition model in the force field and electric field,the characterisation relationships between the dynamic viscosity,DC conductivity,and test temperature of transformer oil were established.The limita-tions of conventional transformer oil equivalent dielectric relaxation models over a wide temperature range were finally clarified by combining the test findings of the DC con-ductivity over a wide temperature range with observed and simulated calculations.This paper provides an essential theoretical reference when using the FDS test to diagnose the insulation performance of oil-immersed power equipment in extremely cold regions.展开更多
Ince–Gaussian (IG) beams, as eigenfunctions of the paraxial wave equation in elliptical coordinates, are attracting increasing interest owing to their propagation-invariant and full-field properties. Optical amplific...Ince–Gaussian (IG) beams, as eigenfunctions of the paraxial wave equation in elliptical coordinates, are attracting increasing interest owing to their propagation-invariant and full-field properties. Optical amplification via parametric interactions can further expand their application areas, yet it is rarely studied. In this work, we report on a high-fidelity parametric amplifier for IG beams. The nonlinear transformation of the spatial spectra of the signal and associated influences on the beam profiles of the amplified signal, under different pump structures, were theoretically and experimentally investigated. By using a perfect flattop beam as the pump, we show that the transverse structure of IG signals is well maintained,and the distortion induced by radial-mode degeneration is overcome during amplification. This proof-of-principle demonstration paves the way for a mode-independent and distortion-free amplifier of arbitrary structured light and has great significance in relevant areas, such as quantum optics, tunable infrared-laser generation, and image amplification.展开更多
An abundance estimation algorithm based on orthogonal bases is proposed to address the problem of high computational complexity faced by most abundance estimation algorithms that are based on a linear spectral mixing ...An abundance estimation algorithm based on orthogonal bases is proposed to address the problem of high computational complexity faced by most abundance estimation algorithms that are based on a linear spectral mixing model(LSMM) and need to perform determinant operations and matrix inversion operations. The proposed algorithm uses the Gram-Schmidt method to calculate the endmember vector set to obtain the corresponding orthogonal basis set and solve the unmixing equations to obtain the eigenvector of each endmember. The spectral vector to be decomposed is projected onto the eigenvector to obtain projection vector, and the ratio between the length of the projection vector and the length of the orthogonal basis corresponding endmember is calculated to obtain an abundance estimation of the endmember. After a comparative analysis of different algorithms, it is concluded that the proposed algorithm only needs to perform vector inner product operations, thereby significantly reducing the computational complexity. The effectiveness of the algorithm was verified by experiments using simulation data and actual image data.展开更多
文摘Aiming at the problem of long time-consuming and low accuracy of existing age estimation approaches,a new age estimation method using Gabor feature fusion,and an improved atomic search algorithm for feature selection is proposed.Firstly,texture features of five scales and eight directions in the face region are extracted by Gabor wavelet transform.The statistical histogram is introduced to encode and fuse the directional index with the largest feature value on Gabor scales.Secondly,a new hybrid feature selection algorithm chaotic improved atom search optimisation with simulated annealing(CIASO-SA)is presented,which is based on an improved atomic search algorithm and the simulated annealing algorithm.Besides,the CIASO-SA algorithm introduces a chaos mechanism during atomic initialisation,significantly improving the convergence speed and accuracy of the algorithm.Finally,a support vector machine(SVM)is used to get classification results of the age group.To verify the performance of the proposed algorithm,face images with three resolutions in the Adience dataset are tested.Using the Gabor real part fusion feature at 48�48 resolution,the average accuracy and 1-off accuracy of age classification exhibit a maximum of 60.4%and 85.9%,respectively.Obtained results prove the superiority of the proposed algorithm over the state-of-the-art methods,which is of great referential value for application to the mobile terminals.
基金Heilongjiang Provincial Postdoctoral Science Foundation,Grant/Award Number:LBH-Z22202The technology project of the State Grid Corporation of China Headquarters,Grant/Award Number:5500-202330167A-1-1-ZN。
文摘The main part of oil-immersed power equipment is oil-paper insulation.At lower ambient temperatures,transformer oil will become viscous.As a result,compared to those at room temperature or operating temperature,the frequency domain dielectric properties of oil-paper insulation at low temperatures are drastically different.For evaluating the insulation condition of electrical equipment,it is essential to accurately determine their dielectric properties.This paper described the FDS test,the DC conductivity test,and the transformer oil viscosity test,which was carried out in a laboratory environment for different ageing of oil-immersed pressboard and transformer oil at 233–373 K.The ef-fects of temperature on the dielectric properties at the competing mechanisms of polarisation and conductivity loss were clarified based on variations of the FDS curves.Considering the viscosity change of ageing transformer oil at low temperatures,the Arrhenius and VFT viscosity equations were used to achieve a fitting calculation in the different temperature zones.Based on the molecular/ion transition model in the force field and electric field,the characterisation relationships between the dynamic viscosity,DC conductivity,and test temperature of transformer oil were established.The limita-tions of conventional transformer oil equivalent dielectric relaxation models over a wide temperature range were finally clarified by combining the test findings of the DC con-ductivity over a wide temperature range with observed and simulated calculations.This paper provides an essential theoretical reference when using the FDS test to diagnose the insulation performance of oil-immersed power equipment in extremely cold regions.
基金supported by the National Natural Science Foundation of China (NSFC) (Nos. 62075050 and 61975047)the High-Level Talents Project of Heilongjiang Province (No. 2020GSP12)。
文摘Ince–Gaussian (IG) beams, as eigenfunctions of the paraxial wave equation in elliptical coordinates, are attracting increasing interest owing to their propagation-invariant and full-field properties. Optical amplification via parametric interactions can further expand their application areas, yet it is rarely studied. In this work, we report on a high-fidelity parametric amplifier for IG beams. The nonlinear transformation of the spatial spectra of the signal and associated influences on the beam profiles of the amplified signal, under different pump structures, were theoretically and experimentally investigated. By using a perfect flattop beam as the pump, we show that the transverse structure of IG signals is well maintained,and the distortion induced by radial-mode degeneration is overcome during amplification. This proof-of-principle demonstration paves the way for a mode-independent and distortion-free amplifier of arbitrary structured light and has great significance in relevant areas, such as quantum optics, tunable infrared-laser generation, and image amplification.
基金supported by the National Natural Science Foundation of China(No.51677057)
文摘An abundance estimation algorithm based on orthogonal bases is proposed to address the problem of high computational complexity faced by most abundance estimation algorithms that are based on a linear spectral mixing model(LSMM) and need to perform determinant operations and matrix inversion operations. The proposed algorithm uses the Gram-Schmidt method to calculate the endmember vector set to obtain the corresponding orthogonal basis set and solve the unmixing equations to obtain the eigenvector of each endmember. The spectral vector to be decomposed is projected onto the eigenvector to obtain projection vector, and the ratio between the length of the projection vector and the length of the orthogonal basis corresponding endmember is calculated to obtain an abundance estimation of the endmember. After a comparative analysis of different algorithms, it is concluded that the proposed algorithm only needs to perform vector inner product operations, thereby significantly reducing the computational complexity. The effectiveness of the algorithm was verified by experiments using simulation data and actual image data.
