查询词典 difference equation

The beginning of this article gives the definition of elliptic curve, ellipse standard equation, and the long axis of oval, short, with an area of the formula of a binary quadratic equation of the circumstances under which the judge said to provide the basis of an oval, as well as the conditions in this the long axis of the ellipse, short, with an area of what is the formula?

本文开始给出了椭圆曲线的定义，椭圆的标准方程，及椭圆的长轴，短轴，面积公式，对一个二元二次方程在什么情况下表示椭圆提供了判断依据，以及在此条件下的椭圆的长轴，短轴，面积公式是什么？

For the four laterals simply supported plate, the transverse deflection of plate is expanded over the modal shapes, the electroelastic model with self-sensing actuators plate is given, and the current is considered as output variable of measurement equation. Generalized modal coordinates being state variables, LQG and H∞control is proceeded using the state space equation.

将板的横向位移按模态展开，对配置压电自感作动器的薄板建立了模型，给出以广义模态坐标为状态变量的状态方程和以传感电流为输出的观测方程，在此基础上，对系统进行了LQG控制和H∞控制。

In the fourth chapter, theoretical analysis was performed by using the stochastic oscillation theory, the stochastic averaging equation and the FPK equation were deduced and some simulation results about the stationary probability density function of such system were given.

第四章利用随机振动理论，对系统进行了一些理论分析，推导了此类系统的随机平均方程与FPK方程，并初步给出了一些关于系统响应的平稳概率密度的模拟结果。

According to structural characteristics of floating slab tracks, a track segment element was taken between two adjacent fasteners. For each element, rails were regarded as Euler beams supported by discrete viscoelastic supports. The fasteners and rubber supports were replaced by a linear spring and damp. So the vibration model of the floating slab track was established. In constructing vibration model of a metro train, each car of the metro train with two suspensions was modeled as a multi-rigid body system, in which rigid bodies were connected with each other by a linear spring and damp. Combining the potential energy of vertical vibration of the track with that of the metro train, the total potential energy of vertical vibration of the train and track was obtained. And then, the matrix equation of vertical vibration of the system was established using the principle of total potential energy with stationary value in elastic system dynamics and the "set-in-right-position" rule for formulating system matrices. The vibration responses of the system can be obtained by solving the matrix equation with the direct time integration such as Wilson-θ method.

摘 要：针对浮置板式轨道结构特点，取相邻2个扣件之间的轨道为1个轨段单元，钢轨视为连续弹性点支承Euler梁，浮置板视为弹性薄板，扣件系统及橡胶支座均模拟为线性弹簧及粘滞阻尼器，建立浮置板式轨道振动模型；将城轨列车中的车辆均离散为多刚体系统，各刚体之间通过线性弹簧及粘滞阻尼器相连，建立列车振动模型；将浮置板式轨道及列车振动势能叠加，得到系统竖向振动总势能；基于弹性系统动力学总势能不变值原理及形成系统矩阵的"对号入座"法则，建立此系统竖向振动矩阵方程；采用Wilson-θ逐步积分法求解此矩阵方程，得出此系统竖向振动响应。

We structure a general equilibrium dynamic model of optimize behavior under the stick price, the model is made up of IS equation , AS equation and interest rate rule , these three equations :::: We utilize state space model and Kalman filter to measure the variable which can't be observed --The China Real Interest Rate Gap and China potential GDP .

我们构建了粘性价格下基于主体最优化行为的一般均衡动态模型，模型由IS方程、AS方程和利率规则这三个方程组成：：：：我们利用状态空间模型和卡尔曼滤波的方法对于不可观测变量——中国实际利率缺口和中国潜在GDP进行了度量。

Moreover, applying the theories of backward stochastic differential equation and partial differential equation, the models have been converted.

并借助于倒向随机微分方程以及偏微分方程的重要理论完成了对模型的转化。

By introducing random factors on differential equation, stochastic differential equation is formed.

微分方程反映了系统中的动态变化情况，在实际生产生活中得到了广泛的应用；微分方程的基础上引入随机因素，便形成了随机微分方程。

This thesis will be expanded from two aspects: first, delta-sequence obtained by cubic spline interpolation cardinal function showed the properties of symmetry, Riesz basis and interpolation. Non linear convection diffusion equation (Burgers′equation) was used as an example. Then we modified this delta-sequence to improve the attenuation, the same example was used in numerical application.

在小波方法与PDE算法相结合方面，本文主要从两方面入手：首先是以样条插值基函数为基础构造δ-序列核，以非线性对流扩散方程为例给出了一种数值算法；进而对三次样条插值基函数进行改进，构造新的具有更快衰减性质的δ-序列核，同样以非线性对流扩散方程为例验证了新函数在数值求解中的有效性。

In the study of the Lagrange stability of impact motion, we give some conditions of the bouncing solution of the asymptotically linear equation which is bounded or unbounded. Outside of a large disc, using the symplectic transformation of the Hamilton system to estimate the iteration of the successor map. Applying the Moser's small twist theorem, we get the invariant curves and then give the proof of the bouncing solutions which is bounded. We will estimate the successor map of the equation directly for proving the unboundedness of the bouncing solutions.

在碰撞运动的Lagrange稳定性的讨论中，给出了渐近线性方程碰撞解有界或无界的条件，在充分大的圆盘外，通过Hamilton系统的辛坐标变换的角度平均来估计后继映射的迭代，应用Moser小扭转定理得到不变曲线从而给出在一定条件下碰撞解有界的证明，碰撞解无界性的证明将采用直接估计后继映射的方法给出。

The discretisation of the velocity space in the kinetic theory of gases allowsus to replace an integro-partial-differential equation,the Boltzmann equation,by a system of hyperbolic semi-linear partial differential equations.

在气体运动论中将速度空间离散化处理，使得我们可以用一个双曲型的半线性偏微分方程组来取代Boltzmann方程这个积分微分方程。

I'm going tor her!

我这就去救她！

As rise are design to help keep a several toney , a brain chemical at continues lever.

SSRI被设计来帮助保持血液中的复合胺即在大脑中一个连续水平的化学物质。