In some nonlinear dynamic systems,the state variables function usually can be separated from the control variables function,which brings much trouble to the identifcation of such systems.To well solve this problem,an improved least squares support vector regression(LSSVR)model with multiple-kernel is proposed and the model is applied to the nonlinear separable system identifcation.This method utilizes the excellent nonlinear mapping ability of Morlet wavelet kernel function and combines the state and control variables information into a kernel matrix.Using the composite wavelet kernel,the LSSVR includes two nonlinear functions,whose variables are the state variables and the control ones respectively,in this way,the regression function can gain better nonlinear mapping ability,and it can simulate almost any curve in quadratic continuous integral space.Then,they are used to identify the two functions in the separable nonlinear dynamic system.Simulation results show that the multiple-kernel LSSVR method can greatly improve the identifcation accuracy than the single kernel method,and the Morlet wavelet kernel is more effcient than the other kernels.
为实现高效、精准的高光谱图像分类,该文利用低秩矩阵恢复从原始数据中提取低维特征,实现高光谱图像的压缩表示。针对高光谱应用的特殊性,该文算法基于结构相似性度量(Structural Similarity Index Measurement,SSIM)对矩阵恢复过程提出了信噪分离约束,有助于选择更优的模型参数,增强表示的准确性。实验证明,相比现有相关方法,该文算法能够有效去除高光谱图像中的噪声,表示结果更为鲁棒;在仅使用低维特征时,仍能达到较高的分类精度。
