共查询到20条相似文献,搜索用时 78 毫秒
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1.引言 关于代数Riccati方程(ARE)的研究是大量的.从数值角度看,有关数值方法,扰动理论的研究已比较深入.而关于条件数理论的研究则还不多[3],[6]. Ryers[1]研究了时连续代数 Riccati方程可稳解的条件数; Kenney和 Hewer[3]讨论了时连续代数 Riccati方程(以下简称 CTARE)可稳解的敏度分析,给出了一阶扰动界,引进了条件数; Sun[6]从最佳向后扰动理论角度研究了时离散代数Riccati方程(以下简称DTARE)可稳解的条件数;徐树方[8]针对 CTA… 相似文献
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非线性DEDS的周期时间部分合并配置与能稳性 总被引:2,自引:0,他引:2
对于具有状态反馈的非自治非线性DEDS,通过引入强连通系的最大能并子集,定义了周期时间部分合并配置和能稳性,给出了周期时间部分合并配置的一个充要条件以及能稳性的一个充分条件,前者推广了已有结果. 相似文献
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冀敏 《数学的实践与认识》2013,43(10)
现代控制增稳飞机是高达几十阶的复杂系统,将其降阶为特定形式的低阶等效系统才能与已有飞行品质规范进行比较,进而预测和评价飞机飞行品质.从时域角度出发,提出了一种高阶控制增稳系统等效拟配参数在线辨识方法.分析了时域等效系统拟配的基本方法,提出了等效系统实时在线拟配的系统框架思路,基于Tustin变换法推导了由高阶系统时域响应获取四阶等效系统参数的数学公式,应用最小二乘法在MATLAB中实现了算法编程,并用试飞数据验证了所提方法的可行性.计算结果表明,所提方法可以快速准确地实现高阶控制增稳系统的等效系统参数辨识. 相似文献
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董旺远 《数学物理学报(A辑)》2008,28(6):1133-1149
该文研究了一类半线性抛物型方程组平衡解的有限维反馈能稳性, 控制器由对应于平衡解的线性化系统的LQ问题所导出. 该文发现在受控系统中如何施加控制是与平衡解有关的, 对于不同的平衡解, 在受控系统中应施加不同的控制. 相似文献
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董小娟 《高校应用数学学报(A辑)》2010,25(2)
研究了具有周期混合信号的带时滞项和non-Gaussian噪声项的非对称双稳系统的随机共振.首先应用统一色噪声理论近似了non-Gaussian噪声项,然后用小时滞近似理论简化了时滞项,进而根据两态理论得到了系统的输出信噪比的表达式.并讨论了系统的非对称性r,时滞量τ和噪声相关时间τ_0对信噪比的影响,发现信噪比曲线上出现了随机多振现象,这种现象与不考虑时滞影响时系统中的随机共振现象是不同的.且数值模拟表明,系统的非对称性r,时滞量τ和周期混合信号的影响使得信噪比曲线上出现了多个峰值. 相似文献
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阶梯状黄土边坡稳定性分析的关键是估算其稳定系数的最小值.稳定系数的求解涉及诸多因素且计算过程繁杂,传统优化算法往往不能有效地搜索到其全局最小解.为此,提出一种改进的自适应遗传算法.算法对基因变量空间进行网格状划分,采用迭代选优法建立均匀分布的初始种群,运用优质个体保留遗传策略,并按照特定的准则自适应地调整交叉概率和变异概率,提高算法的全局搜索能力和收敛速度.实例应用表明算法能够快速有效地收敛于土坡稳定系数的全局最小解,且计算结果与实际情况更加吻合. 相似文献
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本文利用GL算法,通过权衡五项指标,对白英中总皂苷含量的测定方法进行稳定性分析,得到了稳定中心,使得能够更为准确地测定白英中总皂苷含量。 相似文献
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Ammar Khemmoudj Taklit Hamadouche 《Mathematical Methods in the Applied Sciences》2016,39(12):3282-3293
In this paper, we are concerned with asymptotic stability of a class of Bresse‐type system with three boundary dissipations. The beam has a rigid body attached to its free end. We show that exponential stabilization can be achieved by applying force and moment feedback boundary controls on the shear, longitudinal, and transverse displacement velocities at the point of contact between the mass and the beam. Our method is based on the operator semigroup technique, the multiplier technique, and the contradiction argument of the frequency domain method. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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多层厚壁圆筒频率方程的简化及一类贝塞尔函数递推公式 总被引:1,自引:0,他引:1
本文从理论上研究了相同材料的多层厚壁圆筒径向振动的频率方程,证明若干层相互接触的层筒的整体频率方程,可以用单个厚壁圆筒的频率方程替代,从而大大简化了求解过程.并从该实际问题出发,推导出了一类贝塞尔函数的递推公式. 相似文献
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This paper is concerned with the free vibration of the fluid-filled multi-walled carbon nanotubes (MWCNTs) with simply supported ends. Based on simplified Donnell’s cylindrical shell model and potential flow theory, the effect of internal fluid on the coupling vibration of the MWCNTs-fluid system is discussed in detail. The results show that the resonant frequencies are decreased due to the effect of the fluid, and the fluid has only a little influence on the associated amplitude ratio in MWCNTs corresponding to the natural resonant frequency (frequency of the innermost tube), while plays a significant role in the associated amplitude ratios corresponding to the intertube resonant frequency. For the natural resonant frequency, the vibration mode is coaxial. However, for the intertube resonant frequency, the system shows complex noncoaxial vibration, which plays a critical role in electronic and transport properties of carbon nanotubes (CNTs). 相似文献
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SiShoukui 《高校应用数学学报(英文版)》1999,14(4):467-474
In this paper,the boundary stabiligstion of tbe Timoshenko equation of a nononiform beam,with clarrmped boundary condition at one end and witb bending moment and shear force controls at the other end, is considered. It is proved that the system is exponentially stahilizable when the bending moment and shear force controls are simultaneously appiied. The frequency domain method and the multiplier technique are used. 相似文献
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We discuss the relationship between the frequency and the growth of H-harmonic functions on the Heisenberg group.Precisely,we prove that an H-harmonic function must be a polynomial if its frequency is globally bounded.Moreover,we show that a class of H-harmonic functions are homogeneous polynomials provided that the frequency of such a function is equal to some constant. 相似文献
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V. P. Maslov 《Mathematical Notes》2006,80(1-2):214-223
We obtain two new distributions in frequency probability theory and demonstrate them, in particular, in the example of frequency dictionaries. One of these distributions gives a logarithmic correction to the Zipf-Mandelbrot law, and the other describes the “tails” of the distribution. 相似文献
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Richard Barakat 《Stochastic Processes and their Applications》1978,8(1):77-85
The average frequency with which a trigonometric sum having linearly independent frequencies achieves a given value in a specified time interval was solved by Kac in the form of a double integral. In the present paper, Kac's solution is generalized by allowing the amplitudes of the sinusoidal terms to be statistically independent random variables possessing compact probability density functions. The average frequency is expressed as a Fourier cosine series. Representative numerical calculations are shown. The asymptotic form of the average frequency is also discussed. 相似文献
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本文研究具有局部分布反馈与边界反馈耦合控制的非均质Timoshenko梁的镇定问题,利用频域乘子方法,证明了系统能指数稳定 相似文献
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二阶跟踪—微分器的频率特性 总被引:12,自引:0,他引:12
本文给出二阶跟踪—微分器的频率特性 ,此频率特性类似于二阶线性低通滤波器的频率特性 ,但具有线性系统所没有的优点 ,即通带内有较小的相移 ,且无谐振现象 .同时 ,文中指出频率特性与跟踪参数和正弦输入信号幅值之间的关系就是一个简单的“平移” 相似文献