查询词典 derived equation

It is known theoretically that to the variational problem with weak constraints in cost functional J, its Euler equation can be discreted into difference format, by using matrix theory and difference method of partial differential equation we know that there exists optimal selection of weight factors in the cost functional under the condition of minimal variance between analysis field and ideal field.

从理论上可知，对于目标泛函J带有约束条件的变分问题，将其Euler方程离散成差分形式，利用矩阵理论和偏微分方程的差分方法，则目标泛函的权重因子，在分析场和理想场的最小方差意义下存在最优选取。

It's proved that the long duration response is stable under stationary random excitation, when the mean equation of the temperature in all parts of heat conductor shows no difference with the heat conduction differential equation under classical stationary heat conduction condition.

研究表明，在平稳随机激励下，导热系统的长时间响应也是平稳的。

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。

He difference between quantities equation and numerical value equation is analyzed in detail.

从定义、概念、应用以及相互关系等方面对量方程式和数值方程式进行了分析对比，指出了正确使用这两种方程式的重要性和方法。

To obtain state matrix A of linear differential algebra equation, the equation set of the model, then the eigenvalue of state matrix A and its effection on sensitivity of excition system are calculated by QR method.

对模型方程组进行线性化，得到线性微分-代数方程的状态矩阵A；使用QR法，计算状态矩阵A的特征值及特征值对发电机励磁系统参数灵敏度。

This paper gives the probabilistic interpretation for one system of the second order quasilinear parabolic partial differential equations combined with an algebra equation using fully coupled forward-backward stochastic differential equation.

本文利用完全耦合的正倒向随机微分方程，对一类耦合了一个代数方程的二阶拟线性抛物型偏微分方程系统，给出概率表示。

Traffic momentum differential equation and Euler′s equation are constructed by means of differential calculus.

通过对交通流参数的微分分析，建立了交通流的运动微分方程和欧拉方程。

Because the equation is a various coefficients second-order parabolical partial differential equation,explicit difference formats usually have high condition for stability. Implicit difference formats have good stability,but they must calculate a set of algebraic equations,which are too complex.

由于泥沙扩散方程是一个二维变系数的抛物型方程，对于多维的方程，显格式往往稳定性要求很高，而隐格式虽然稳定性较好，但它要解大型的代数方程组，工作量也非常大，为了克服这两种格式的不足，常用ADI法求解，但仍存在一些计算量偏大等不足之处，因此构造出更好的差分格式是有必要的。

Among used machine learning methods, the gradient descent method is widely used to train various classifiers, such as Back-propagation neural network and linear text classifier. However, the gradient descent method is easily trapped into a local minimum and slowly converges. Thus, this study presents a gradient forecasting search method based on prediction methods to enhance the performance of the gradient descent method in order to develop a more efficient and precise machine learning method for Web mining.However, a prediction method with few sample data items and precise forecasting ability is a key issue to the gradient forecasting search method. Applying statistic-based prediction methods to implement GFSM is unsuitable because they require a large number of data items to model a prediction model. In the contrast with statistic-based prediction methods, GM(1,1) grey prediction model does not need a large number of data items to build a prediction model, and it has low computational load. However, the original GM(1,1) grey prediction model uses a mathematical hypothesis and approximation to transform a continuous differential equation into a discrete difference equation in order to model a forecasting model.

其中梯度法是一个最常被使用来实现机器学习的方法之一，然而梯度法具有学习速度慢以及容易陷入局部最佳解的缺点，因此，本研究提出一个梯度预测搜寻法则(gradient forecasting search method， GFSM)来改善传统梯度法的缺点，用来提升一些以梯度学习法则为基础的分类器在资讯探勘上的效率与正确性；而一个所需资料量少、计算复杂度低且精确的预测模型是梯度预测搜寻法能否有效进行最佳解搜寻之关键因素，传统统计为基础之预测方法的缺点是需要较大量的数据进行预测，因此计算复杂度高，灰色预测模型具有建模资料少且计算复杂度低等优点，然而灰色预测理论以连续之微分方程式为基础，并且透过一些数学上的假设与近似，将连续之微分方程式转换成离散之差分方程式来对离散型资料进行建模及预测，这样的作法不尽合理，且缺乏数学理论上的完备性，因为在转换过程中已经造成建模上的误差，且建模过程仅考虑相邻的两个资料点关系，无法正确反应数列未来的变化趋势。

This paper proposes a new differential equation for production declining rate ,which has different form from differential equation of J.

研究提出了一种新的产量递减率微分方程，这个方程与J J阿尔普斯的递减率微分方程在形式上是不同的，并由此推导出了一种油气藏可采储量预测方法。

I was up all night because I was in pain, she said.

我整夜，因为我在疼痛，她说。

A crow caws /craoks.

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