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1.
讨论了一类双臂三关节柔性梁系统的分析问题.首先,建立了一个与柔性梁的偏微分方程组及初值边值条件相应的希尔伯特空间中的一阶发展系统.接着讨论系统算子的谱性质和半群性质.最后借助系统算子的谱性质和半群性质提出并证明了柔性梁系统的指数稳定性.  相似文献   

2.
首次将时滞现象引入到线性切换系统的模型中,研究含时滞的线性切换系统的能控性及其判定条件.全部工作由三部分组成.第Ⅱ部分,主要研究含单时滞的线性切换系统的能控性及其判定准则.首先给出周期型系统的单周期能控性和多周期能控性的定义和充要条件,其次给出非周期系统的能控性的定义和充要条件.  相似文献   

3.
用投影方法求耗散广义Hamilton约束系统的李群积分   总被引:1,自引:0,他引:1  
针对耗散广义Hamilton约束系统.通过引入拉格朗日乘子和采用投影技术,给出了一种保持动力系统内在结构和约束不变性的李群积分法.首先将带约束条件的耗散Hamilton系统化为无约束广义Hamilton系统.进而讨论了无约束广义Hamilton系统的李群积分法,最后给出了广义Hamilton约束系统李群积分的投影方法.采用投影技术保证了约束的不变性,引入拉格朗日乘子后,在向约束流形投影时不会破坏原动力系统的李群结构.讨论的内容仅限于完整约束系统,通过数值例题说明了方法的有效性.  相似文献   

4.
基于小波包分解的非线性时变系统辩识   总被引:2,自引:0,他引:2  
在实际应用中,经常会碰到非线性时变系统,它们的辨识和建模比较困难.本文采用时变Hammerstein模型描述时变非线性系统.该模型可以以较简单的方式刻划系统的时变特性和非线性特性.然后用小波包对时变系数进行展开,把时变系统的辨识转化为对时不变系数的辨识.  相似文献   

5.
本文旨在研究连续的混沌系统是否存在“混沌+混沌=有序”的现象.证明了两个双向耦合的连续混沌系统在一些情况下可产生有序的动力学行为.作为例子,通过选取适当的耦合参数使Lorenz系统以及Chen和Lee引入的混沌系统同步,进而对同步系统的动力学行为进行了理论分析和数值模拟.结果表明,逐渐改变参数,系统实现了从混沌到有序的过渡.  相似文献   

6.
一类混杂动态系统的能控性(Ⅲ)--含多时滞的情形   总被引:2,自引:0,他引:2  
首次将时滞现象引入到线性切换系统的模型中,研究含有时滞线性切换系统的能控性及其判定条件.全部工作由三部分组成.第Ⅲ部分,主要研究含多时滞的线性切换系统的能控性及其判定规则.首先给出周期型系统的单周能控性和多周期能控性的定义和充要条件,其次给出非周期系统的能控性的定义和充要条件.最后,研究时滞大小不一致的情形,指出能控性与时滞大小无关.  相似文献   

7.
苏保河 《运筹学学报》2007,11(1):93-101
研究被检测系统的一个模型,假定系统有4种运行状态(正常工作、异常工作、正常故障和异常故障).系统故障时不需检测,系统工作时必须经过检测才能知道它是正常还是异常.系统开始工作后,每隔一段随机时间对它检测一次,直到系统故障或检测出系统处于异常状态为止.利用概率分析和随机模型的密度演化方法,导出了系统的一些新的可靠性指标和最优检测策略.  相似文献   

8.
本文研究了一大类刚体系统的单侧约束运动的局部和整体性质.主要结论是;局部地,这类系统的运动相当于某带过黎曼流形上的质点的运动;整体地,在能量守恒的假定下.这类系统相当于某带边黎曼流形上的台球系统.  相似文献   

9.
研究具有HollingIV功能性反应和脉冲的周期捕食食饵系统.找到了影响该系统动力学行为的阈值Ro.证明了当Ro〈1时,该系统的食饵灭绝周期解是局部渐近稳定的;当R0〉1时,该系统的食饵灭绝周期解变得不稳定且食饵将一致持久.  相似文献   

10.
具有预警功能的可修复系统   总被引:4,自引:0,他引:4  
研究了一个具有预警功能的可修复系统.通过选取空间和定义系统算子,将模型方程转化成为了抽象Cauchy问题.然后利用算子半群理论证明了系统解的存在唯一性与指数稳定性.另外,当风险系数趋于无穷时,这种系统逼近于一种具有弱解的模型系统,利用这个性质可得出相应结论并给出了数值仿真例子.  相似文献   

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We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.  相似文献   

13.
It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.  相似文献   

14.
As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years (2001-2005). The main topics are: convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.  相似文献   

15.
张丽娜  吴建华 《数学进展》2008,37(1):115-117
One of the most fundamental problems in theoretical biology is to explain the mechanisms by which patterns and forms are created in the'living world. In his seminal paper "The Chemical Basis of Morphogenesis", Turing showed that a system of coupled reaction-diffusion equations can be used to describe patterns and forms in biological systems. However, the first experimental evidence to the Turing patterns was observed by De Kepper and her associates(1990) on the CIMA reaction in an open unstirred reactor, almost 40 years after Turing's prediction. Lengyel and Epstein characterized this famous experiment using a system of reaction-diffusion equations. The Lengyel-Epstein model is in the form as follows  相似文献   

16.
Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.  相似文献   

17.
In this paper, we study the explicit representation and convergence of (0, 1; 0)-interpolation on infinite interval, which means to determine a polynomial of degree ≤ 3n - 2 when the function values are prescribed at two set of points namely the zeros of Hn(x) and H′n(x) and the first derivatives at the zeros of H′n(x).  相似文献   

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