随机

First ,it is proved that a positive Hermite form corresponds uniquely to a positive self2adjoint operator in a complete random inner product module ,then this result leads directly to the proof of the main result of...

值得指出的是：完备随机内积模上Friedrichs 定理的证明中所涉及的一系列基本概念与方法都是以随机共轭空间理论为出发点的，与经典情形完全不同。

Firstly, the study of the mechanical model. The three-dimensional finite element model is established, and it is condensed into M-dof interlamination structural model. The structural dynamic analysis is implemented by use of three-dimensional finite element model and M-dof interlamination structural model.

本文通过严谨的数学推导，得出"力学不耦合"的超高层结构顺风向和尾流旋涡干扰引起的横风向振动随机响应公式，并编制了相关计算程序，深入研究了应用随机振动理论进行结构风振反应分析的方法。

Experimental results show that the method proposed can overcomethe block effect caused by the linear or spline interpolation method, and the error is less than that inlinear, spline and ran...

实验表明所提出的方法能够克服传统的线性或样条插值所产生的方块效应，并且比一些随机插值算法如随机中点偏移插值算法失真度小。

This method can reduce the required time to generate variates, and when the inverse distribution function is sufficiently smooth, the interpolation formula has a higher convergence order.

非均匀随机变量的产生是运行仿真模型的需要，而产生非均匀随机变量却没有一个通用的方法，这给实现仿真的自动化和一些实际应用带来了困难。

An efficient method is developed for integrating interruptible electricity contracts in probabilistic production simulation of power systems.

提出了一种结合可中断电力合同交易的电力系统随机生产模拟方法，其中把可中断电力等效为具有随机停运特性的灵活发电资源。

Suppose that the random Doeblin condition is satisfied, we prove that the invariant measure exists and any initial distibution convergence to the measure with an exponential rate.

假设随机"Doeblin"条件成立，我们证明了随机环境的马氏链的不变测度存在，且任何初始分布以指数收敛速度到些不变测度。

By performing an inverse Laplace transformation of the stretch exponential function a distribution curve of the diffusivity is obtained which is enables the molecular weight distribution to be extracted.The results show that the width of the molecular weight distribution increasing as the average molecular weight decreases during the degradation process.

结果发现，在降解过程中随着聚合物平均分子量的降低，体系中的分子量分布不断变宽，这一结果与GPC实验结果完全吻合，而且从PFG实验中得到的平均分子量变化趋势和随机断裂方式下的Monte Carlo模拟实验结果十分吻合，据此可以认为聚合物的降解是一个随机断裂的过程。

Chapter 5 deals with the solvable theorem of adaptive inverse optimal control problems for a class of stochastic nonlinear systems driven by Wiener noises of unknown covariance. The systems are depicted by It〓 stochastic differential equations. By using an adaptive backstepping algorithm and stochastic control Lyapunov functions, the designing procedure of control laws of global asymptotic stability in probability and adaptive inverse optimal stabilization in probability are presented systematically. Adaptive control laws and parameter update laws can be obtained at the same time by this design scheme.

在第5章中，针对具有方差不确定Wiener噪声扰动和未知定常参数的随机非线性系统（假设方差的F—范数是一个常数或一个缓慢变化的量，对其进行在线辨识），给出并证明了自适应逆最优控制问题可解定理，基于随机Lyapunov定理和It〓微分规则，采用自适应Backstepping设计方法，系统地设计了全局依概率渐近稳定和自适应逆最优控制策略，这种设计方法可同时获得控制策略和自适应律，计算机数值仿真结果表明该控制算法是有效性的。

In our thesis, contents are organized as following In Chapter 1 we present our topic's internal and overseas research situations, theoretical and practical significance, and introduce the research object and contents, and the main contributions of this dissertation. Chapter 2 reviews the development of the stability results for nonlinear systems and some relevant recent results, which include Lyapunov and LaSalle-Yoshizawa theorems for nonlinear systems, and stochastic edition for stochastic nonlinear systems. Sontag's formula for systems affine in control is presented in the frame of CLF. The concepts of disturbance attenuation and the inverse optimality are also explained in this Chapter. In chapter 3 we present the solvable theorem of inverse optimal gain assignment problem, design the inverse optimal controller and the inverse optimal tracking controller for strict-feedback nonlinear continuous systems with unknown time-varing bounded disturbances and constant unknown parameters using an adaptive backstepping algorithm, which are nonlinear, continuous and are easier to realize. These designs are fully systematic and the algorithm can be directly coded in symbolic software. The results of simulation show the effectiveness of the control algorithms.

论文的结构如下：在第1章中，给出了本文研究课题的研究现状、理论意义和实际应用，并介绍了本文的研究对象、研究内容以及主要贡献；在第2章中，针对确定性非线性系统和随机非线性系统，分别介绍了Lyapunov定理、LaSalle-Yoshizawa定理及其随机版本；对仿射系统，在控制Lyapunov函数框架下，给出了Sontag公式；同时给出了非线性系统扰动抑制和逆最优控制问题的基本概念；在第3章中，针对具有未知时变有界扰动和未知定常参数的一类不确定非线性系统，给出并证明了逆最优增益配置可解定理，使用自适应Backstepping算法和均值定理，系统地设计了自适应逆最优控制器和逆最优跟踪器，这种设计方法可同时获得逆最优控制策略和自适应律，简单明了，仿真结果表明该控制算法的有效性，并给出了性能估计。

In Chapter 4 we discuss the solvable theorem of adaptive inverse optimal control problems, and proceed with controller designs of global asymptotic stability in probability, adaptive inverse optimal stabilization in probability and output-feedback adaptive inverse optimal stabilization in probability for strict-feedback stochastic nonlinear continuous systems with additive standard Wiener noises and constant unknown parameters using It〓's differentiation rule and an adaptive backstepping algorithm. Control laws and adaptive laws can be obtained at one time by this design scheme. Many simulations have been performed to validate the properties of the proposed adaptive control scheme.

在第4章中，针对具有标准Wiener噪声扰动和未知定常参数的不确定随机非线性系统，提出并证明了自适应逆最优控制问题可解定理，构造了适当形式的四次型随机控制Lvapunov函数，基于It〓微分规则和自适应Backstepping算法，系统地设计了全局依概率渐近稳定控制器、自适应逆最优控制器、输出反馈逆最优控制器以及在设计中如何处理二阶Hessian矩阵函数的方法，这种方法可同时获得控制律和自适应律，通过实例仿真，表明该控制算法是有效性的。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。