查询词典 simultaneous differential equations

This thesis first proposes the idea of EM in view of the drawbacks existing in traditional modeling methods. The main approaches and the general procedure of EM are described and the recent work of GP is surveyed using a taxonomy. Secondly, in terms of model types, the EM problem of complex functions, the EM problem of system of ordinary differential equations and the EM problem of higher-order ordinary differential equations are studied in detail. Finally, some advantages and disadvantages of the EM method are summarized at the end of this thesis.

本文首先针对传统建模方法的不足，提出了演化建模的思想，阐述了演化建模采用的主要方法和一般步骤，并分类概括了遗传程序设计目前的研究内容；然后，按照所建模型的类型不同，分三章详细研究了复杂函数的演化建模问题、常微分方程组的演化建模问题以及高阶常微分方程的演化建模问题；最后，本文对演化建模的主要特点和目前存在的主要问题作了概括和总结。

Then, it studies the supply chain management system as a complex system to confirm the state existing during operating of the system. After that, it conducts a probability analysis on the state which the system located by applying supplement variable method, and establishes the model of distributed parameter system in a form of partial differential equations. Combining C0 ? semigroup theory in the functional analysis, it conducts a dynamic analysis on the established mathematical model. Using this method, it obtains the mathematical expression of the dynamic solution and the steady state solution, and proves the uniqueness, non-negativity and the asymptotic stability of the system solution. This dissertation applies the Matlab tool and uses two-step, three-step Simpson integral equation to imitate the condition of system solution. Then, it adds possible mode of failure and the optimization adjustment state to the system, based on which it has established the distributed parameter system model which is described by partial differential system of equations. Combining the functional analysis C0 ? semigroup theory, it studies the established mathematical model, and obtains the mathematical expression of the dynamic solution system and the steady state solution. It has proven the existing of uniqueness of the system solution, the asymptotic stability of system solution and the system solution. In addition, it has lying the theory rationale for further analysis and the research on the optimization of system.

本文首先简要综述了供应链理论、可靠性研究、鲁棒性研究以及供应链鲁棒性研究的现状；然后，将供应链系统作为一个复杂系统来分析，确定了系统运行过程中所经历的状态，通过引入补充变量的方法，建立了用偏微分方程组描述的分布参数系统模型，用泛函分析中的C_0 -半群理论得到了系统动态解和稳态解的数学表达式，证明了系统解存在的唯一性、非负性和指数阶渐近稳定性；并借助Matlab工具，利用二阶、三阶辛普森积分方程模拟系统解的性态，并给出系统动态解的仿真图；本文又对上述系统增加了系统可能失效状态和优化调整状态，并在此基础上建立了用偏微分方程组描述的分布参数系统模型，同样用泛函分析中的C_0 -半群理论对所建立的数学模型进行了研究，得到系统动态解和稳态解的数学表达式，证明了系统动态解存在的唯一性、非负性及渐近稳定性，为进一步分析和研究供应链优化奠定了理论基础。

Oscillation theory of ordinary differential equations in the theory of differential equations is an important branch, it has a profound background of the physical and mathematical model.

常微分方程振动性理论是微分方程理论中的一个十分重要的分支，它具有深刻的物理背景和数学模型。

These transfer equations were used to reestablish the entropy transfer equation for the electromagnetic fluid,and further to reconstitute the differential component equations for different forms of exergy and the differential equation for total exergy in the fluid by the definitions of thermal,pressure,chemical,kinetic,potential and electromagnetic forms of exergy.

通过定义热火用、压火用、化学火用、动能火用、势能火用、电磁火用，重新构建了不同形式火用传递的分量方程及其总火用传递方程。

Based on Wu's elimination method and "divide-and-conquer" strategy, the undetermined coefficient method for constructing polynomial conservation laws of nonlinear differential-difference equations was improved. Furthermore, a Maple package CLawDDEs was developed to automatically derive conserved densities and associated fluxes of polynomial differential-difference equations.

基于吴消元法和"分治"策略，改进了基于标度不变性构造非线性微分差分方程多项式形式守恒律的待定系数算法，并在计算机代数系统Maple上实现了改进后的算法，其中的软件包CLawDDEs可自动推导出微分差分方程的守恒密度及连带流。

To investigate the dynamic stability of a two-degree-of-freedom manipulator as a system,differential equations of motion for this system were established on the basis of the Lagrange equation,and perturbed differential equations with period coefficients were derived for the period motion of this system by applying the perturbance theory.

为了研究两自由度机械手系统的动力学稳定性，基于拉格朗日方程给出了它的运动微分方程，并用扰动理论确定系统周期运动具有周期系数的扰动微分方程；根据F loquet理论对该系统扰动微分方程的平衡点的稳定性进行了分析，并用数值方法研究了平衡点失稳后的倍周期分岔过程。

The Jacobi pseudospectral methods are applied to numericalsolutions of singular differential equations,differential equations in infinite intervals andin disc.

事实上，通过适当的变量代换，我们可把无界区域问题转化成某些特定的退化系数的有界区域上的奇异问题。

Main contents are as follows :In chapter one, we give a survey to the development and current state of the oscillation of differential equations and difference equations. We also introduce some preliminary material , including some basic concepts of the oscillation theory and some important fixed point theorems.In chapter two, we investigate the oscillation of second order self-conjugate differential equation with impulses.

本文由五章组成，主要内容如下：第一章概述了微分方程及差分方程的应用背景和国内、外研究状况，这一章也包括一些预备知识，如有关微分方程、差分方程理论的基本概念和重要的不动点定理。

Mechanical models and differential equations of motion for high speed pantographs;2. By the principle, differential equations of motion for variable-mass nonholonomic systems constrained to the fixed axis rotation are obtained.

建立了变质量力学系统在定轴转动参考系中的Jourdain原理，由此得到了受定轴转动约束的变质量力学系统运动微分方程，给出了准坐标形式，最后举例说明方程的应用。

In Chapter 2, starting from the basic fractional ordinary differential equations,weapply a high order approximation of fractional derivative advanced by Lubich to frac-tional differential equation, construct a high numerical difference scheme to solve thefractional differential equation, present error analysis of the algorithms theoretically,and prove the consistency ,convergency and stability.

接下来的第二章中，首先从基本的分数阶常微分方程出发，对Lubich提出的一个关于分数阶导数的高阶近似，将其应用于分数阶微分方程，构造高阶数值差分格式来进行分数阶微分方程的数值求解，并在理论上给出这一算法的误差分析，证明了它的相容性，收敛性和稳定性。

Anna: No, I've got a hangover.

不是，我昨晚宿醉了。

We head into the mountains in Su's new Land Cruiser, stop for lunch at a scenic restaurant and then hang around drinking beer and eating fruit as two of his employees attempt to lure the birds with a tape recording of the fowl's mating call.

我们坐上苏的巡逻车向山顶出发，在一家风景优美的餐馆吃了中饭。然后我们喝着啤酒吃着水果四处逛。