用警戒雷达跟踪海面舰船目标时,由于舰船运动速度较慢,这使得其在雷达两次观测之间的位移与雷达本身的测量误差是可比拟的。这种情况下,传统的Kalman滤波在付出较大计算量的同时并不能显著提高跟踪精度。为此,针对海面匀速直线运动的舰...用警戒雷达跟踪海面舰船目标时,由于舰船运动速度较慢,这使得其在雷达两次观测之间的位移与雷达本身的测量误差是可比拟的。这种情况下,传统的Kalman滤波在付出较大计算量的同时并不能显著提高跟踪精度。为此,针对海面匀速直线运动的舰船目标,提出了一种基于线性递推回归的投影滤波跟踪算法(Projection Filter based on Linear Recursive Regression,PFLRR),仿真实验表明该算法的滤波性能与Kalman滤波相当,但其计算量仅为Kalman滤波的2/5左右。展开更多
Based on analyzing the limitations of the commonly used back-propagation neural network （BPNN）, a wavelet neural network （WNN） is adopted as the nonlinear river channel flood forecasting method replacing the BPNN....Based on analyzing the limitations of the commonly used back-propagation neural network （BPNN）, a wavelet neural network （WNN） is adopted as the nonlinear river channel flood forecasting method replacing the BPNN. The WNN has the characteristics of fast convergence and improved capability of nonlinear approximation. For the purpose of adapting the timevarying characteristics of flood routing, the WNN is coupled with an AR real-time correction model. The AR model is utilized to calculate the forecast error. The coefficients of the AR real-time correction model are dynamically updated by an adaptive fading factor recursive least square（RLS） method. The application of the flood forecasting method in the cross section of Xijiang River at Gaoyao shows its effectiveness.展开更多
The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling...The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling of multi-output systems by LS-SVR. The multi-output LS-SVR is derived in detail. To avoid the inversion of large matrix, the recursive algorithm of the parameters is given, which makes the online algorithm of LS-SVR practical. Since the computing time increases with the number of training samples, the sparseness is studied based on the pro-jection of online LS-SVR. The residual of projection less than a threshold is omitted, so that a lot of samples are kept out of the training set and the sparseness is obtained. The standard LS-SVR, nonsparse online LS-SVR and sparse online LS-SVR with different threshold are used for modeling the isomerization of C8 aromatics. The root-mean-square-error (RMSE), number of support vectors and running time of three algorithms are compared and the result indicates that the performance of sparse online LS-SVR is more favorable.展开更多
文摘用警戒雷达跟踪海面舰船目标时,由于舰船运动速度较慢,这使得其在雷达两次观测之间的位移与雷达本身的测量误差是可比拟的。这种情况下,传统的Kalman滤波在付出较大计算量的同时并不能显著提高跟踪精度。为此,针对海面匀速直线运动的舰船目标,提出了一种基于线性递推回归的投影滤波跟踪算法(Projection Filter based on Linear Recursive Regression,PFLRR),仿真实验表明该算法的滤波性能与Kalman滤波相当,但其计算量仅为Kalman滤波的2/5左右。
基金The National Natural Science Foundation of China(No.50479017).
文摘Based on analyzing the limitations of the commonly used back-propagation neural network （BPNN）, a wavelet neural network （WNN） is adopted as the nonlinear river channel flood forecasting method replacing the BPNN. The WNN has the characteristics of fast convergence and improved capability of nonlinear approximation. For the purpose of adapting the timevarying characteristics of flood routing, the WNN is coupled with an AR real-time correction model. The AR model is utilized to calculate the forecast error. The coefficients of the AR real-time correction model are dynamically updated by an adaptive fading factor recursive least square（RLS） method. The application of the flood forecasting method in the cross section of Xijiang River at Gaoyao shows its effectiveness.
基金Supported by the National Creative Research Groups Science Foundation of China (60721062)the National Basic Research Program of China (2007CB714000)
文摘The least squares support vector regression (LS-SVR) is usually used for the modeling of single output system, but it is not well suitable for the actual multi-input-multi-output system. The paper aims at the modeling of multi-output systems by LS-SVR. The multi-output LS-SVR is derived in detail. To avoid the inversion of large matrix, the recursive algorithm of the parameters is given, which makes the online algorithm of LS-SVR practical. Since the computing time increases with the number of training samples, the sparseness is studied based on the pro-jection of online LS-SVR. The residual of projection less than a threshold is omitted, so that a lot of samples are kept out of the training set and the sparseness is obtained. The standard LS-SVR, nonsparse online LS-SVR and sparse online LS-SVR with different threshold are used for modeling the isomerization of C8 aromatics. The root-mean-square-error (RMSE), number of support vectors and running time of three algorithms are compared and the result indicates that the performance of sparse online LS-SVR is more favorable.
