查询词典 approximate differentiability

First, we discuss the classification of existing spatial indexing methods and point out the problems of them. Second, the approximate representation of spatial objects is given. Third, the structure and the algorithm of CP tree, which based...

本文首先介绍了目前常用的几类空间索引技术及其特点，接着讨论了面向地理信息的空间索引技术面临的基本问题，提出了基于凸多边形的空间索引结构—— CP-树，并侧重分析了其空间运算算法及时空效率，最后指出了空间索引技术所存在的问题及下一步的研究方向。

A variational method with differential forms gives better precision for numerical solution of transport critical problem based on spherical geometry, and its computation seems simple than other approximate methods.

对于球几何问题，讨论了一种基于微分方程的变分形式求解方法，数值计算显示达到了较满意的精度，而且计算过程比起其他近似方法要简单

First of all, we use approximate method of the super-symmetric quantum mechanics to calculate super-potential and eigenvalues of spheroidal functions in the first several terms. Further more , we derive the ground eigenfunction in the first order terms, which is very useful for applying of the spheroidal wave function probably

首先我们使用近似的超对称量子力学方法计算出前几阶超势和广义椭球函数的本征值；接着根据之前所求得的超势和本征值推导出广义椭球函数一阶基态波函数，该超对称量子力学方法的引入及一阶基态波函数形式将有利于广义椭球函数深入研究

The Welsh Springer Spaniel head is unique and should in no way approximate that of other spaniel breeds.

威尔斯激飞猎犬的头部非常独特，与其他猎鹬犬品种的头部完全不同。

We then say that whatever kind of picture these make, I can always approximate as closely as I wish to the description of it by covering the surface with a sufficiently fine square mesh, and then saying of every square whether it is black or white.

于是我们可以说，不管这些斑块构成一种什么图像，只要用一张足够精细的方格网覆盖住这个表面，然后说出每一个方格是黑的还是白的，我就总是能够使对这个表面的描述达到任意程度的近似。

Secondly, method of Taylor series is used to approximate the slow manifold and the O approximation of the slow manifold is given; slow dynamics such as saddle node bifurcation which has been proven to be the same as that for the full system is analyzed; at the same time, fast dynamics including bifurcation conditions and domain of attractor of the stable equilibrium are also analyzed; the attracting region which consists of the stable manifold of the unstable equilibrium and stable equilibrium is given; we found that when the inner flux decay increases, the domain of attractor is enlarged.

首先，给出了电力系统SMIB模型的时间尺度分解，得到标准的奇异摄动模型；其次，利用幂级数方法，给出了慢流形的O近似M〓，分析了在慢流形M〓上的慢动态，得到了慢子系统的鞍结分支值，并证明此分支值与原系统的鞍结分支值相同；分析了快子系统的平衡点和全局分支的存在条件，给出由不稳定平衡点的稳定流形与稳定平衡点形成的吸引域；并研究内部电压对稳定域的影响，发现稳定域随内部电压增加而扩大；最后给出整个系统的稳定平衡点的近似吸引域。

Aimed at the problem of choosing the initial value when the Newton method is used to compute the controlling unstable equilibrium point, a practical and rigorous solving scheme was presented: by identifying the controlling load bus of the given fault, and using the Thevenin equivalent circuit to represent the rest of the system at the state of the post disturbance stable equilibrium point, using the steady equivalent circuit to represent the induction motor in composite load, and then using the torque characteristics of induction motor, a point near the CUEP is gained to be the initial value. The second order normal forms was used to approximate the stable manifold of CUEP, and the local approximating boundary of the region of attraction of the post disturbance stable equilibrium point was gained. Then just by simulating the state of the system at the fault clearing time, the transient voltage stability of the system could be determined.

针对采用牛顿法求取故障后系统主导不稳定平衡点(controlling unstable equilibrium point，CUEP)存在的初值选取难题，提出一种实用但不失严谨的解决方案：通过识别给定故障的主导负荷母线，对主导负荷母线以外系统由故障后稳定平衡点处的状态进行戴维南等值，对负荷中感应电动机部分采用其稳态等值电路，再由感应电动机的转矩特性求得CUEP附近的一个点作为近似的CUEP，以此为迭代初值可靠求得CUEP；采用二阶正规型来近似CUEP的稳定流形的方法求得近似的局部吸引域边界；由仿真得到故障清除时刻系统的状态并根据该状态是否位于吸引域内判断系统的暂态电压稳定性。

To obtain the approximate solution, the pressure acting on the gate is divided into two parts, one is the fluctuating pressure of the flow underneath the stationary gate, which is investigated with experiment; the other is the hydrodynamic pressure due to the vibration, which is equivalent to the attached mass matrix, damping matrix and stiffness matrix of the equation.

为了获得方程的近似解，本文将作用在闸门上的水动力荷载分为两个部分，一是闸门无振动时的水流压力，用水力模型试验测定；二是由于闸门振动引起流场扰动的动水压力，通过运动方程中的附加质量阵，附加阻尼阵和附加刚度阵来等效。

The stationary probability density function and the stationary mean out-crossing rate of the response of ship nonlinear roll-motion subjected to additive stochastic white noise excitation are examined by a new approximate method in this paper.

应用求解FPK方程近似解的一种新理论研究白噪声激励下船舶非线性横摇运动的联合概率密度函数及稳定期望穿阈率。

The approximate stationary probability density function for the response of multi-degree-of-freedom dissipated Hamiltonian systems to Poisson white noises are obtained by solving the four-order generalized Fokker-Planck-Kolmogorov equation using perturbation approach.

通过用摄动法求解四阶广义福克－普朗克方程，得到泊松白噪声激励的多自由度耗散的哈密顿系统的近似平稳响应概率密度函数。

Chinese traditional virtue is humility and wariness,the compliment and praise to the others should be declination

中国人的传统美德是谦虚谨慎，对别人的恭维和夸奖应是推辞。如

We bought this house on the never-never.

我们以分期付款的方式买下这座房子。