查询词典 difference equation

The optimal control law obtained consists of linear analytic functions and a compensation term which is a series sum of the adjoint vectors. The analytic functions can be found by solving a Riccati matrix difference equation and a matrix difference equation. The compensation term can be obtained by a recursion formula that solves adjoint vector equations.

得到的最优输出跟踪控制律由状态向量的线性解析函数和伴随向量级数形式的补偿项组成，其解析函数由一次性求解Riccati矩阵差分方程和矩阵差分方程得到，补偿项由求解伴随向量差分方程的递推公式得到。

The main idea of the finite difference method is as follows: We consider the discrete difference equation with the finite alphas as approximate substitution for the differential equation with the continuous variant and boundary conditions.

有限差分方法的基本思想是用离散的，只含有有限个未知数的差分方程去近似代替连续变量的微分方程及边界条件，并把相应的差分方程解作为微分方程的近似解。

Differential equations and difference equations are powerful tools that describe the law of nature, but it is difficult to find their general solutions. Therefore , there has been an increasing interest in the study of the nature of solutions of differential equation and difference equation in theory.

微分方程及差分方程是用来描述自然现象变化规律的一种有力工具，由于寻求其通解十分困难，故从理论上探讨解的性态一直是近年来研究的热点问题。

Through the limit difference method,the partial differential equation of the semiconductor device is transformed into a difference equation,and the corresponding boundary condition is discretized with high accuracy.

采用有限差分法把器件工作的偏微分方程转化为差分方程，并将相应的边界条件转化为精度较高的离散化形式。

The modeling of GM (1,1) model is to gain difference equation by dispersing albinism differential equation, then to estimate model parameters by the difference equation.

GM(1，1)模型的建模过程是由白化微分方程离散化得到差分方程，再由该差分方程估计模型参数。

The relation between difference equation and differential equation is studied by analyzing the mechanism in building grey models, and a "bridge" is set up between difference equation and differential equation by sampling theorem and state transition matrix.

通过对灰色系统模型建模机理进行深入剖析，利用采样定理和状态转移矩阵在差分方程和微分方程之间架起一座桥梁，通过算例仿真实验证明了该算法的有效性。

The main content of the study includes: the policy variables are classified into two types, which are continuous policy variable and discrete policy variable, and the two variable is analyzed respectively; as to the continuous policy variable, use reasonable weighting to synthesize comprehensive policy indicator to reflect the comprehensiveness of each main policy indicator; undertake regression analysis for the comprehensive policy indicator, economic and stock market variable and get the effect of all kinds of comprehensive policy indictor variables on the economy and stock market; undertake regression analysis for data on the economic indicator and the data on the stock market and get the relationship between the economy and the stock market; use event research method to analyze its effect on the stock market and get some corresponding conclusions; structure the differential or difference equation groups on the interactive relationship among the variable economy, stock market and policy and do the difference operation and constitute simultaneous equation with the original main variables one after another; use quantitative regression method and solve the coefficient of the simultaneous equation to predict the operating tendency.

本研究主要内容包括：将政策变量划分为连续性政策变量和离散政策变量两个类型，并分别进行分析；对于连续性政策变量，采取合理的权重来合成政策综合指标，反映各主要政策指标的综合力度大小；将各政策综合指标与经济、股市变量进行回归分析，获得各类政策综合指标变量对经济、股市影响程度的大小；将经济指标数据与股市数据进行回归分析，获得经济与股市之间关系的大小；采取事件研究方法来分析其对股市的影响程度；构建关于经济、股市与政策各主要变量之间互动关系的微分或差分方程组，进行差分运算，并以此与原来各主要变量组成联立方程；运用计量回归方法，求出联立方程系数用于预测。

Within this context, four specific areas are addressed:(1) By means of finite integration technique, a new kind of the first order partial difference equation is derived from the original disperse transmission line equation of the uniform waveguide's. As it is the kind of one dimension Dirichlet's boundary problem, it is convenient for us to solve this equation from the leapfrog scheme. Because computation is carried out in one dimension, both high calculation efficiency and precision have been obtained in this method. Meanwhile, this method provide us a different selection to simulate the transient response of waveguide with non-simplical, for examples cylinder and elliptic waveguide, and avoid solving the second order equation, or using finite difference time domain to simulate a three dimension problem, sometimes the latter precision is not satisfied with the need, or low efficiency.

在这一研究内容下，主要研究四个方面的问题：(1)在完成金属波导传输线方程时域形式的基础之上，应用有限积分技术，把波导特征模式的色散传输线方程，化简为一组新的一阶偏微分方程组，该边值问题属一维Dirichlet边值问题，从而便于用蛙跳格式求解，由于是在一维中计算，该方法具有很高计算效率和精度，从而避免了以往为得到金属波导中特征模的时域响应特性，须要求解二阶方程，或用时域有限差分方法求解三维问题的方法，对于后者来说，计算有时是不准确的，或是很耗时的例如计算诸如圆波导、椭圆波导等其它复杂形状的波导。

The input - output relationship of any linear time-invariant discrete system can be described by a difference equation The complete solution of a linear difference equation consists of two parts: the free component and the forced component.

任何一个线性时不变离散系统的输入输出关系都可用线性差分方程式来描写。差分方程式的解答包括两部分：即自由分量和强制分量。

Based on the given results of second order boundary value problem, the existence of solutions of nonlinear differential-difference equation and unique of solutions of Hammerstein type integro-differential-difference linear equation were established because Hammerstein linear equation featured only one solution.

以二阶边值问题的已知结果为基础，建立了微分差分非线性方程解的存在性，以及Hammerstein型线性方程解的唯一性。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

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如果有任何问题，你可以随时联系我。