Because of cloudy and rainy weather in south China, optical remote sens-ing images often can＇t be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model an...Because of cloudy and rainy weather in south China, optical remote sens-ing images often can＇t be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model and effect of ENVISAT/SAR and HJ-1A satel ite multispectral remote sensing images. Based on the ARSIS strat-egy, using the wavelet transform and the Interaction between the Band Structure Model （IBSM）, the research progressed the ENVISAT satel ite SAR and the HJ-1A satel ite CCD images wavelet decomposition, and low/high frequency coefficient re-construction, and obtained the fusion images through the inverse wavelet transform. In the light of low and high-frequency images have different characteristics in differ-ent areas, different fusion rules which can enhance the integration process of self-adaptive were taken, with comparisons with the PCA transformation, IHS transfor-mation and other traditional methods by subjective and the corresponding quantita-tive evaluation. Furthermore, the research extracted the bands and NDVI values around the fusion with GPS samples, analyzed and explained the fusion effect. The results showed that the spectral distortion of wavelet fusion, IHS transform, PCA transform images was 0.101 6, 0.326 1 and 1.277 2, respectively and entropy was 14.701 5, 11.899 3 and 13.229 3, respectively, the wavelet fusion is the highest. The method of wavelet maintained good spectral capability, and visual effects while improved the spatial resolution, the information interpretation effect was much better than other two methods.展开更多
We show that a class of spectral problems are related to the spectral problem of the Volterra lattice through a gauge transformation. The transformation is given. We hope that our discussion can draw attention to the ...We show that a class of spectral problems are related to the spectral problem of the Volterra lattice through a gauge transformation. The transformation is given. We hope that our discussion can draw attention to the study of gauge transformation theory of differential-difference integrable systems.展开更多
Heavy metal contamination in waste incineration fly ash poses serious environmental and public health risks,necessitating efficient and precise detection methods.Traditional techniques require complex sample preparati...Heavy metal contamination in waste incineration fly ash poses serious environmental and public health risks,necessitating efficient and precise detection methods.Traditional techniques require complex sample preparation and lengthy analysis,limiting their suitability for on-site or real-time monitoring.To address this,this study proposes a rapid detection method using visible and near-infrared reflectance spectroscopy to improve efficiency and reduce costs.Zn(zinc)and Pb(lead)spectral characteristics were analyzed through first-order differentiation(FD),second-order differentiation(SD),de-trending(DT),and logarithm of the reciprocal(LogInv)transformations,followed by continuous wavelet transform(CWT)to extract key bands(max|r|=0.78).A stacking model integrating partial least squares regression(PLSR),back-propagation neural network(BPNN),support vector regression(SVR),random forest(RF),and extreme gradient boosting(XGBoost)was developed to optimize spectral transformation and inversion modeling.Stacking outperformed individual models,achieving the highest accuracy for Zn(R^(2)=0.748)and Pb(R^(2)=0.735)with CWT-SD and CWT-FD transformation.BPNN exhibited overfitting in small samples,whereas PLSR was constrained by linear assumptions.In contrast,stacking combines the strengths of all the base models,improving accuracy and stability.This study elucidates the spectral characteristics of fly ash and validates the effectiveness of stacking in hyperspectral heavy metal prediction.The findings provide theoretical and technical support for efficient,non-destructive detection,with promising applications in waste incineration management and environmental monitoring.展开更多
The exact short time propagator, in a form similar to the Crank-Nicholson method but in the spirit of spectrally transformed Hamiltonian, was proposed to solve the triatomic reactive time-dependent schrodinger equatio...The exact short time propagator, in a form similar to the Crank-Nicholson method but in the spirit of spectrally transformed Hamiltonian, was proposed to solve the triatomic reactive time-dependent schrodinger equation. This new propagator is exact and unconditionally convergent for calculating reactive scattering processes with large time step sizes. In order to improve the computational efficiency, the spectral difference method was applied. This resulted the Hamiltonian with elements confined in a narrow diagonal band. In contrast to our previous theoretical work, the discrete variable representation was applied and resulted in full Hamiltonian matrix. As examples, the collision energy-dependent probability of the triatomic H＋H2 and O＋O2 reaction are calculated. The numerical results demonstrate that this new propagator is numerically accurate and capable of propagating the wave packet with large time steps. However, the efficiency and accuracy of this new propagator strongly depend on the mathematical method for solving the involved linear equations and the choice of preconditioner.展开更多
It is proposed to use the spectral form of mathematical description of control systems for modeling continuous-time Markov random processes described by linear stochastic differential equations with additive or multip...It is proposed to use the spectral form of mathematical description of control systems for modeling continuous-time Markov random processes described by linear stochastic differential equations with additive or multiplicative noise.The obtained results are applied to solve the output process analysis problem and the optimal estimation problem.展开更多
A general n-th order spectral transform and a technique for inverting this transform is described in this paper and the usefulness of the whole procedure is illustrated by the solution of a system of nonlinear Klein G...A general n-th order spectral transform and a technique for inverting this transform is described in this paper and the usefulness of the whole procedure is illustrated by the solution of a system of nonlinear Klein Gordon equations.展开更多
基金supported by the National Natural Science Foundation of China(41171336)the Project of Jiangsu Province Agricultural Science and Technology Innovation Fund(CX12-3054)
文摘Because of cloudy and rainy weather in south China, optical remote sens-ing images often can＇t be obtained easily. With the regional trial results in Baoying, Jiangsu province, this paper explored the fusion model and effect of ENVISAT/SAR and HJ-1A satel ite multispectral remote sensing images. Based on the ARSIS strat-egy, using the wavelet transform and the Interaction between the Band Structure Model （IBSM）, the research progressed the ENVISAT satel ite SAR and the HJ-1A satel ite CCD images wavelet decomposition, and low/high frequency coefficient re-construction, and obtained the fusion images through the inverse wavelet transform. In the light of low and high-frequency images have different characteristics in differ-ent areas, different fusion rules which can enhance the integration process of self-adaptive were taken, with comparisons with the PCA transformation, IHS transfor-mation and other traditional methods by subjective and the corresponding quantita-tive evaluation. Furthermore, the research extracted the bands and NDVI values around the fusion with GPS samples, analyzed and explained the fusion effect. The results showed that the spectral distortion of wavelet fusion, IHS transform, PCA transform images was 0.101 6, 0.326 1 and 1.277 2, respectively and entropy was 14.701 5, 11.899 3 and 13.229 3, respectively, the wavelet fusion is the highest. The method of wavelet maintained good spectral capability, and visual effects while improved the spatial resolution, the information interpretation effect was much better than other two methods.
基金Supported by the National Natural Science Foundation of China under Grant No 11371241
文摘We show that a class of spectral problems are related to the spectral problem of the Volterra lattice through a gauge transformation. The transformation is given. We hope that our discussion can draw attention to the study of gauge transformation theory of differential-difference integrable systems.
基金supported by the National Key R&D Program of China(No.2024YFC3909000)the Major Scientific and Technological Innovation Projects of Hangzhou(No.2022AIZD0163)。
文摘Heavy metal contamination in waste incineration fly ash poses serious environmental and public health risks,necessitating efficient and precise detection methods.Traditional techniques require complex sample preparation and lengthy analysis,limiting their suitability for on-site or real-time monitoring.To address this,this study proposes a rapid detection method using visible and near-infrared reflectance spectroscopy to improve efficiency and reduce costs.Zn(zinc)and Pb(lead)spectral characteristics were analyzed through first-order differentiation(FD),second-order differentiation(SD),de-trending(DT),and logarithm of the reciprocal(LogInv)transformations,followed by continuous wavelet transform(CWT)to extract key bands(max|r|=0.78).A stacking model integrating partial least squares regression(PLSR),back-propagation neural network(BPNN),support vector regression(SVR),random forest(RF),and extreme gradient boosting(XGBoost)was developed to optimize spectral transformation and inversion modeling.Stacking outperformed individual models,achieving the highest accuracy for Zn(R^(2)=0.748)and Pb(R^(2)=0.735)with CWT-SD and CWT-FD transformation.BPNN exhibited overfitting in small samples,whereas PLSR was constrained by linear assumptions.In contrast,stacking combines the strengths of all the base models,improving accuracy and stability.This study elucidates the spectral characteristics of fly ash and validates the effectiveness of stacking in hyperspectral heavy metal prediction.The findings provide theoretical and technical support for efficient,non-destructive detection,with promising applications in waste incineration management and environmental monitoring.
文摘The exact short time propagator, in a form similar to the Crank-Nicholson method but in the spirit of spectrally transformed Hamiltonian, was proposed to solve the triatomic reactive time-dependent schrodinger equation. This new propagator is exact and unconditionally convergent for calculating reactive scattering processes with large time step sizes. In order to improve the computational efficiency, the spectral difference method was applied. This resulted the Hamiltonian with elements confined in a narrow diagonal band. In contrast to our previous theoretical work, the discrete variable representation was applied and resulted in full Hamiltonian matrix. As examples, the collision energy-dependent probability of the triatomic H＋H2 and O＋O2 reaction are calculated. The numerical results demonstrate that this new propagator is numerically accurate and capable of propagating the wave packet with large time steps. However, the efficiency and accuracy of this new propagator strongly depend on the mathematical method for solving the involved linear equations and the choice of preconditioner.
基金financially supported by the Russian Foundation for Basic Research,Project No.17-08-00530.
文摘It is proposed to use the spectral form of mathematical description of control systems for modeling continuous-time Markov random processes described by linear stochastic differential equations with additive or multiplicative noise.The obtained results are applied to solve the output process analysis problem and the optimal estimation problem.
文摘A general n-th order spectral transform and a technique for inverting this transform is described in this paper and the usefulness of the whole procedure is illustrated by the solution of a system of nonlinear Klein Gordon equations.
