In order to accurately describe the dynamic characteristics of flight vehicles through aerodynamic modeling, an adaptive wavelet neural network (AWNN) aerodynamic modeling method is proposed, based on subset kernel pr...In order to accurately describe the dynamic characteristics of flight vehicles through aerodynamic modeling, an adaptive wavelet neural network (AWNN) aerodynamic modeling method is proposed, based on subset kernel principal components analysis (SKPCA) feature extraction. Firstly, by fuzzy C-means clustering, some samples are selected from the training sample set to constitute a sample subset. Then, the obtained samples subset is used to execute SKPCA for extracting basic features of the training samples. Finally, using the extracted basic features, the AWNN aerodynamic model is established. The experimental results show that, in 50 times repetitive modeling, the modeling ability of the method proposed is better than that of other six methods. It only needs about half the modeling time of KPCA-AWNN under a close prediction accuracy, and can easily determine the model parameters. This enables it to be effective and feasible to construct the aerodynamic modeling for flight vehicles.展开更多
Photo dissociation dynamics of diatomic molecular ion HBr＋ interacting with ultra fast laser pulses of different envelop function has been presented both in zero and non zero temperature environment. The calculations...Photo dissociation dynamics of diatomic molecular ion HBr＋ interacting with ultra fast laser pulses of different envelop function has been presented both in zero and non zero temperature environment. The calculations pertain primarily to the ground electronic state of the molecular ion HBr＋. The used potential of HBr＋ is calibrated with the help of the ab initio theoretical calculation at the CCSD/6-311＋＋G（3df, 2pd） level and then fitted with appropriate Morse parameters. The numerical bound states vibrational eigenvalues obtained by the time independent Fourier Grid Hamiltonian method have been compared with analytical values of the fitted Morse potential. The effect of temperature, pulse envelops function, and light intensity on the dissociation process has been explored.展开更多
基金Project(51209167) supported by Youth Project of the National Natural Science Foundation of ChinaProject(2012JM8026) supported by Shaanxi Provincial Natural Science Foundation, China
文摘In order to accurately describe the dynamic characteristics of flight vehicles through aerodynamic modeling, an adaptive wavelet neural network (AWNN) aerodynamic modeling method is proposed, based on subset kernel principal components analysis (SKPCA) feature extraction. Firstly, by fuzzy C-means clustering, some samples are selected from the training sample set to constitute a sample subset. Then, the obtained samples subset is used to execute SKPCA for extracting basic features of the training samples. Finally, using the extracted basic features, the AWNN aerodynamic model is established. The experimental results show that, in 50 times repetitive modeling, the modeling ability of the method proposed is better than that of other six methods. It only needs about half the modeling time of KPCA-AWNN under a close prediction accuracy, and can easily determine the model parameters. This enables it to be effective and feasible to construct the aerodynamic modeling for flight vehicles.
文摘Photo dissociation dynamics of diatomic molecular ion HBr＋ interacting with ultra fast laser pulses of different envelop function has been presented both in zero and non zero temperature environment. The calculations pertain primarily to the ground electronic state of the molecular ion HBr＋. The used potential of HBr＋ is calibrated with the help of the ab initio theoretical calculation at the CCSD/6-311＋＋G（3df, 2pd） level and then fitted with appropriate Morse parameters. The numerical bound states vibrational eigenvalues obtained by the time independent Fourier Grid Hamiltonian method have been compared with analytical values of the fitted Morse potential. The effect of temperature, pulse envelops function, and light intensity on the dissociation process has been explored.
