One dimensional non-steady, non-Darcy flow of water in a rock stratum was reduced into a system described by six ordinary differential equations involving five controlling parameters. Through response computations and...One dimensional non-steady, non-Darcy flow of water in a rock stratum was reduced into a system described by six ordinary differential equations involving five controlling parameters. Through response computations and time series analysis, chaotic behavior in the reduced system was discussed in details. Firstly, the dynamical response of the reduced system under a set of parameters was calculated, and the power spectrum of the attractor was obtained through fast Lagrangian transformation; then the phase space was reconstructed by fixing embedding dimension to be 6 and delay time to range from 1 to 20, and the correlation dimension of the attractor was calculated based on the curves under the coordinates of logarithm of correlation integral vs. logarithm of covering radius; and lastly, the Lyapunov indices of the attractor were calculated by using Gram-Schmit's orthogonalization method. The results show that the power spectrum of the attractor is continuous; the correlation dimension of the attractor is equal to 2.36; among the Lyapunov indices, LE1, LE2, LE3 are positive, LE5, LE6 are negative, and LE4 fluctuates near zero. All the analysis indicates that there may exist chaos in the system of non-steady, non-Darcy flow.展开更多
The digital simulation technology is adopted to establish the flight environment and scenario,which realizes the flight display instrument interface and unusual attitude recovery task.The humancomputer interaction(HCI...The digital simulation technology is adopted to establish the flight environment and scenario,which realizes the flight display instrument interface and unusual attitude recovery task.The humancomputer interaction(HCI) experiment is carried out in the flight simulation system,and the behavior performances and physiological parameters are recorded as the evaluation indices of mental workload.Participants are required to perform the unusual attitude recovery tasks and keep monitoring the target flight indicators.Once the unusual attitude occurs,the corresponding operation of steering wheel is expected to be taken immediately to response and eliminate it.The results show that most of behavior performances and physiological parameters are sensitive to mental workload and some of the indices are significantly correlative.展开更多
基金supported by the National Natural Science Foundation of China (No.50874104)
文摘One dimensional non-steady, non-Darcy flow of water in a rock stratum was reduced into a system described by six ordinary differential equations involving five controlling parameters. Through response computations and time series analysis, chaotic behavior in the reduced system was discussed in details. Firstly, the dynamical response of the reduced system under a set of parameters was calculated, and the power spectrum of the attractor was obtained through fast Lagrangian transformation; then the phase space was reconstructed by fixing embedding dimension to be 6 and delay time to range from 1 to 20, and the correlation dimension of the attractor was calculated based on the curves under the coordinates of logarithm of correlation integral vs. logarithm of covering radius; and lastly, the Lyapunov indices of the attractor were calculated by using Gram-Schmit's orthogonalization method. The results show that the power spectrum of the attractor is continuous; the correlation dimension of the attractor is equal to 2.36; among the Lyapunov indices, LE1, LE2, LE3 are positive, LE5, LE6 are negative, and LE4 fluctuates near zero. All the analysis indicates that there may exist chaos in the system of non-steady, non-Darcy flow.
基金National Basic Research Program of China(No.2010CB734104)Foundation of Graduate Technology Innovation and Practice of Beihang University,China(No.YCSJ-01-201305)
文摘The digital simulation technology is adopted to establish the flight environment and scenario,which realizes the flight display instrument interface and unusual attitude recovery task.The humancomputer interaction(HCI) experiment is carried out in the flight simulation system,and the behavior performances and physiological parameters are recorded as the evaluation indices of mental workload.Participants are required to perform the unusual attitude recovery tasks and keep monitoring the target flight indicators.Once the unusual attitude occurs,the corresponding operation of steering wheel is expected to be taken immediately to response and eliminate it.The results show that most of behavior performances and physiological parameters are sensitive to mental workload and some of the indices are significantly correlative.
