期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
非线性函数的混沌优化方法比较研究 被引量:25
1
作者 杨迪雄 李刚 程耿东 《计算力学学报》 EI CAS CSCD 北大核心 2004年第3期257-262,共6页
已有的混沌优化方法几乎都是利用Logistic映射作为混沌序列发生器,而Logistic映射产生的混沌序列的概率密度函数服从两头多、中间少的切比雪夫型分布,不利于搜索的效率和能力。为此,首先根据Logistic映射混沌轨道点密度函数的特点,建立... 已有的混沌优化方法几乎都是利用Logistic映射作为混沌序列发生器,而Logistic映射产生的混沌序列的概率密度函数服从两头多、中间少的切比雪夫型分布,不利于搜索的效率和能力。为此,首先根据Logistic映射混沌轨道点密度函数的特点,建立改进的混沌-BFGS混合优化算法。之后,考虑到Kent映射混沌轨道点密度为均匀分布,建立了基于Kent映射的混沌-BFGS混合优化算法。然后对五种混合优化方法——不加改进的和改进的基于Logistic映射的混沌-BFGS法,基于Kent映射的混沌-BFGS法,MonteCarlo试验-BFGS法,网格-BFGS法进行了研究,分别对3个低维和2个高维非线性复杂测试函数进行优化计算,对它们的全局优化计算效率和寻优能力做了比较,并探讨了混合优化方法全局优化性能差异的原因。结果表明,混沌优化方法是与MonteCarlo方法类似的一种随机性试验优化方法。而且,这类优化方法的计算性能至少与以下因素有关:混沌/随机序列的统计性质,优化问题全局最优点位置。 展开更多
关键词 全局最优化 混沌优化方法 非线性 混沌/随机序列 概率密度函效
下载PDF
First-passage failure of harmonically and stochastically excited Duffing oscillator with delayed feedback control 被引量:3
2
作者 FENG ChangShui ZHU WeiQiu 《Science China(Technological Sciences)》 SCIE EI CAS 2011年第5期1072-1077,共6页
The first-passage failure of Duffing oscillator with the delayed feedback control under the combined harmonic and white-noise excitations is investigated. First, the time-delayed feedback control force is expressed ap... The first-passage failure of Duffing oscillator with the delayed feedback control under the combined harmonic and white-noise excitations is investigated. First, the time-delayed feedback control force is expressed approximately in terms of the system state variables without time delay. Then, the averaged It? stochastic differential equations for the system are derived by using the stochastic averaging method. A backward Kolmogorov equation governing the conditional reliability function and a set of generalized Pontryagin equations governing the conditional moments of the first-passage time are established. Finally, the conditional reliability function, the conditional probability density and moments of the first-passage time are obtained by solving the backward Kolmogorov equation and generalized Pontryagin equations with suitable initial and boundary conditions. The effects of time delay in feedback control force on the conditional reliability function, conditional probability density and moments of the first-passage time are analyzed. The validity of the proposed method is confirmed by digital simulation. 展开更多
关键词 first-passage failure combined harmonic and white noise excitations delayed feedback control stochastic averaging
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部