We consider the escape of the particles multi-state noise. It is shown that, the noise can make over fluctuating potential barrier for a system only driven by a the particles escape over the fluctuating potential barr...We consider the escape of the particles multi-state noise. It is shown that, the noise can make over fluctuating potential barrier for a system only driven by a the particles escape over the fluctuating potential barrier in some circumstances; but in other circumstances, it can not. If the noise can make the particle escape over the fluctuating potential barrier, the mean first passage time （MFPT） can display the phenomenon of multi-resonant-activation. For this phenomenon, there are two kinds of resonant activation to appear. One is resonant activation for the MFPTs as the function of the flipping rates of the fluctuating potential barrier; the other is that for the MFPTs as the functions of the transition rates of the multi-state noise.展开更多
对不同渗透性天然岩芯分别以Cross-plotting法、排水实验法与声波动态法测试其Biot系数,结果表明,对于中高渗岩芯,其结果为k e a?>?>?(k?为Cross-plotting法Biot系数值,e?为排水实验法Biot系数值,a?为声波动态法Biot系数值),而低...对不同渗透性天然岩芯分别以Cross-plotting法、排水实验法与声波动态法测试其Biot系数,结果表明,对于中高渗岩芯,其结果为k e a?>?>?(k?为Cross-plotting法Biot系数值,e?为排水实验法Biot系数值,a?为声波动态法Biot系数值),而低渗岩芯则无法通过排水实验法获取Biot系数。Cross-plotting法测试结果表明,高渗岩芯Biot系数为0.90~1.00内,中渗岩芯为0.80~0.90,而低渗岩芯Biot系数为0.60~0.75。砂岩等中高渗岩芯推荐用排水实验法获得Biot系数,而低渗岩芯则推荐通过Cross-plotting法测试Biot系数。最后,讨论Biot系数的影响因素。展开更多
We studied the feedback maximization of reliability of multi-degree-of-freedom （MDOF） quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. First, the partially averaged Ito equat...We studied the feedback maximization of reliability of multi-degree-of-freedom （MDOF） quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. First, the partially averaged Ito equations are derived by using the stochastic averaging method for quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. Then, the dynamical programming equation and its boundary and final time conditions for the control problems of maximizing the reliability is established from the partially averaged equations by using the dynamical programming principle. The nonlinear stochastic optimal control for maximizing the reliability is determined from the dynamical programming equation and control constrains. The reliability function of optimally controlled systems is obtained by solving the final dynamical programming equation. Finally, the application of the proposed procedure and effectiveness of the control strategy are illustrated by using an example.展开更多
基金Supported by National Natural Science Foundation of China under Grant No. 10975079by K.C. Wong Magna Fund of Ningbo University in Chinaby the Ningbo Natural Sciences Foundation in China
文摘We consider the escape of the particles multi-state noise. It is shown that, the noise can make over fluctuating potential barrier for a system only driven by a the particles escape over the fluctuating potential barrier in some circumstances; but in other circumstances, it can not. If the noise can make the particle escape over the fluctuating potential barrier, the mean first passage time （MFPT） can display the phenomenon of multi-resonant-activation. For this phenomenon, there are two kinds of resonant activation to appear. One is resonant activation for the MFPTs as the function of the flipping rates of the fluctuating potential barrier; the other is that for the MFPTs as the functions of the transition rates of the multi-state noise.
文摘对不同渗透性天然岩芯分别以Cross-plotting法、排水实验法与声波动态法测试其Biot系数,结果表明,对于中高渗岩芯,其结果为k e a?>?>?(k?为Cross-plotting法Biot系数值,e?为排水实验法Biot系数值,a?为声波动态法Biot系数值),而低渗岩芯则无法通过排水实验法获取Biot系数。Cross-plotting法测试结果表明,高渗岩芯Biot系数为0.90~1.00内,中渗岩芯为0.80~0.90,而低渗岩芯Biot系数为0.60~0.75。砂岩等中高渗岩芯推荐用排水实验法获得Biot系数,而低渗岩芯则推荐通过Cross-plotting法测试Biot系数。最后,讨论Biot系数的影响因素。
基金Project supported by the National Natural Science Foundation of China (No. 10772159)the Research Fund for the Doctoral Program of Higher Education of China (No. 20060335125)the Zhejiang Provincial Nature Science Foundation of China (No. Y7080070)
文摘We studied the feedback maximization of reliability of multi-degree-of-freedom （MDOF） quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. First, the partially averaged Ito equations are derived by using the stochastic averaging method for quasi integrable-Hamiltonian systems under combined harmonic and white noise excitations. Then, the dynamical programming equation and its boundary and final time conditions for the control problems of maximizing the reliability is established from the partially averaged equations by using the dynamical programming principle. The nonlinear stochastic optimal control for maximizing the reliability is determined from the dynamical programming equation and control constrains. The reliability function of optimally controlled systems is obtained by solving the final dynamical programming equation. Finally, the application of the proposed procedure and effectiveness of the control strategy are illustrated by using an example.
