查询词典 approximate differential

In this paper, we expand the eigenvalue of Poisson equation using nonconforrn-ing Q1rot element. The principal term of error we get is not negative. In general, the approximate eigenvalue is the upper bound, but the approximate eigenvalue may be the lower bound when the principal term is zero.

本论文对Poisson方程的特征值采用方形旋转双线性非协调元Q_1~(rot元进行展开，得出的误差主项大于或等于零，因此在一般情况下近似特征值是上界，但当主项等于零时近似特征值可能是下界。

This work gives an algorithm to simplify the rational curves in this situation. After the approximate proper index is defined, it is computed by solving the semi-algebra system. The greatest common divisor is obtained according to the computing process of approximate proper index.

为此，讨论了这类有误差的有理参数曲线，定义了近似非恰当参数形式和近似非恰当指数，并通过半代数系统计算近似非恰当指数；在给出近似非恰当指数的同时，得到近似最大公因子。

We have also introduced a method of approximate description of three order systems, using a kind of bang-bang control to approximate the extremal control.

同时利用bang-bang控制来近似极端控制的方法，给出了三阶反稳定系统可控区域的近似描述。

So, in this thesis, discussing the interrelated theory and by using finite element method,fixed Supported Square Plates with openings for different location and size of the openings are investigated. The mechanics rule of plates after openings are presented. A comparison is made for the above plates and the plates supported in three sides and the cantilever of plate in approximate boundary conditions. Some approximate results are obtained.

为此，本文论述了钢筋混凝土板的相关理论并用ANSYS软件分析了四边固支开孔板在不同开孔位置和形状、不同开孔面积的情况下内力的改变，获得了内力改变的规律，并和三边固支板、悬挑板在近似的边界条件下的受力倩况进行比较，得到一些相近的结果。

Finally, to explain the advantage and shortcoming of nonparametric analysis and parametric analysis, and introduce some main shapes of nonpametric regression model: Fourier series, kernel estimators, and spline smoothing. In the meantime, we give the approximate theory and approximate distribution theory of these methods.

阐述了非参数回归分析和参数回归分析的优缺点，介绍了非参数回归模型的几种主要形式：富氏级数，核估计量和样条平滑，给出了这些方法的逼近理论和逼近分布情况。

Base on the fact that a hard-edge aperture function can be expanded into a finite sum of complex Gaussian functions, the approximate analytical expressions for the propagation characters of Hermite-Guassian beams passing through double rectangular apertured are derived. The approximate analysis uses Collins formula. At last, Matlab illustrates some numerical examples.

基于硬边孔函数能拓展成一组有限复高斯函数的和，研究厄米－高斯光束通过双矩孔的传输特性，用Collins公式分析，用Matlab进行一些数值模拟。

Isomap is one of the representative techniques of nonlinear dimensionality reduction.It extends classical multidimensional scaling by considering approximate geodesic distance. However,Isomap is sensitive to noise because the approximate geodesic distance is constructed on the basis of Euclidean distance. In this paper,a kernel-induced distance metric defined in the feature space is introduced instead of the Euclidean distance to evaluate the geodesic distance and construct the corresponding neighborhood graph.

采用核方法在特征空间推导出一类异于欧氏距离的新度量，代替等度规特征映射中的对噪声敏感的欧式距离，用新度量构造测地距离和相应的最小近邻图，提高Isomap算法的抗噪声能力。

If average values before or after catastrophe point when the pressure at both ends reduces exceed the threshold value, judging that there is leak and positioning: calculating approximate wavelet transformation coefficient of pressure data at both ends, initializing searching interval, calculating a signal time delay value corresponding to approximate wavelet transformation coefficient in the searching interval from maximal scale N; converting the time delay value under scale N to that under N-1 by geometric proportion relation; updating the searching interval, repeating above processes until the scale is 0 and positioning based on the time delay value.

若两端压力下降突变点前后的均值变化均超过阈值，判定有泄漏并进行定位：计算两端压力数据的近似小波变换系数，初始化搜索区间，从最大尺度N开始在搜索区间内计算对应近似小波变换系数的信号时延值，利用等比关系将尺度N下的时延估计值转换为N-1下时延估计值，以该值更新搜索区间，重复以上过程至尺度为0，以此时延估计值进行定位。

In the method, the symmetric positive semidefinite matrices are updated to approximate the Hessian matrices of the elemental objective functions and their sum to approximate the Hessian matrix of the objective function.

算法用对称半正定矩阵作为元素目标函数的Hessian阵的近似，使得其和仍然保持目标函数的Hessian阵的某种稀疏性。

As CMAC neural network could not be used to approximate the multi-valued mapping of an inverse hysteresis directly, an inverse hysteretic operator was proposed to transform the multi-valued mapping into a one-to-one mapping which could enable neural networks to approximate the behavior of an inverse hysteresis.

由于CMAC神经网络不能够直接逼近滞回逆这种具有记忆性的多映射现象，通过引入一个滞回逆算子，将多映射的滞回逆转换成一一映射，然后运用CMAC神经网络控制器来逼近这个一一映射，从而建立一个基于CMAC神经网络的滞回逆模型。

Cable dampener cannot be rolled up but must be hung over the cable.

缆帆不能被卷起，必须保证处于展开状态

"This skylark is a present from my master," he says.

"这只云雀是我主人献上的礼物。"他说。