查询词典 solvable equation

In this paper, a further research is conducted to the finite solvable subsimple group, and a more detailed display of its nature and its structure is given.

本文首先对可解有限次单群进行了进一步深入的研究，使其结构和性质更加深入更加详细展现在我们面前。

Many sufficient and necessary conditions for a finite group to be solvable are given, which generalize some known results.

另一方面，我们研究了Sylow-子群的某些特殊子群的半覆盖远离性对有限群结构的影响，给出了一些有限群为p-幂零和超可解的充分条件。

Many scholars have studied these respects and given many important results, for example, the Hupperts famous theorem, namely, a finite group G is supersolvable if and only if every maximal subgroup of G has prime index; a finite group G is nilpotent if and only if every maximal subgroup of G is normal in G; a finite group G is solvable if and only if every maximal subgroup of G is c-normal in G (See it in [70]); etc.

很多学者都在这些方面进行了研究，得到了很多重要的结果，如：著名的Huppert定理，即有限群为超可解当且仅当它的所有极大子群的指数为素数；有限群为幂零当且仅当每个极大子群都正规；有限群为可解当且仅当它的极大子群均c-正规(见[70])；等等。

We know that the solutions of quadratic, cubic and quartic can be expressed by radicals. As to the solution of the quintic which has became an issue for past two or three hundred years, it was not solved until 1832 a great young Mathematician of French named Galois who recommended group theory that proved a polynomial of degree 5 and over 5 can't be solvable by radicals.

中文摘要我们知道二次、三次及四次的方程式都可以用根式表示，至於五次方程式的解迟迟无法解决，这个问题持续了两三百年，直到1832年，一位法国青年Galois在其决斗前夕，在他的遗书中，这位伟大的青年数学家引进了群的理论，证明了：五次及五次以上的方程式，不可能有公式解。

Solvable conditions for electrostatic problems using Gauss s law with direct integral method are presented.

给出应用高斯定理由直接积分法求解静电场问题时的可解性条件，用反例说明常见教科书中对此问题的表述是不完备的

Firstly, the strict-feedback nonlinear systems with unknown virtual control coefficients bi have been studied and the problem of its inverse optimality has been solved, that isThe new solvable theorem of inverse optimal gain assignment problem has been proposed through the method of modular design for the original system.

本论文的内容安排如下：第一部分把上述严格反馈系统进一步推广为具有未知虚拟控制系数bi的严格反馈系非线性统并研究其逆最优问题，即第二部分对于推广之前的系统利用模块设计方法提出新的逆最优增益配置定理。

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。

Given a p-solvable group G and an irreducible Brauer character χof G with respect to the prime p.

给定一个p-可解群G以及G的一个关于该素数p的不可约B rauer特征标χ。

Great. What repertoire did you see?

太棒了。你看的是什么剧目？

I prepared not to accept such ridiculousness:"Please," I said to him.

我可不想理会这套荒谬的东西："请你通情达理一点儿。"