变换点

Utilizing the symmetric property of the hyperbolic complex space-time, we may explain the correspondence relations of time inversions, energy inversions and complex conjugate transformations.

利用双曲复时空间的对称性，可以解释时间反演、能量反演与复共轭变换的对应关系，能够找出正、反粒子的时空对应点。

As the demanding of storage capacity by photographs increases sharply and numerical signal processing units become more and more cheap, effective techniques of lossy compression are generally seperated from some special hardwares and applied to table compter systems.

该文在分析了音频和视频数据同异点的基础上阐述了一种基于离散余弦变换的图像压缩方法，并给出了算法的基本步骤和一些技巧。

After a power spectrum is constructed, empirical wavelet coefficients are used to detect the jump points in the function to obtain the strong consistent estimator of the position and number of the frequencies. Numerical simulations show this method is reliable.

根据它们的协方差函数可以表示为一个Fourier级数，而其Fourier系数可通过协方差函数的逆变换得到的特性，我们对于零均值的近周期相关序列构造了类似于周期图的函数，并构造其经验小波系数，利用频率处于此函数的尖点的特性，以及此性质在经验小波系数中的反映，来确定频率的个数和位置，所有的估计量都是强相合的，此外，数值模拟的结果表明，我们的方法是有效的。

Based on the equilibrium equation of an arch element the cubic nonlinear dynamic model with second order is established and the nonlinear differential dynamic system without constant term is obtained through a transfer process of T=U+b. Hence three fixed points and the homoclinic orbits are found. The critical condition of the chaotic vibration of the elastic arch is given by using the method of Melnikov function. The numerical results of the stationary and chaotic motion are given and discussed.

首先利用拱的单元平衡方程建立了拱的二阶三次非线性动力学模型；然后通过变换使方程转化为不含常数项的非线性微分动力系统，并由此得到无扰动系统的3个不动点与同宿轨道；再用Melnikov函数法给出了发生混沌的临界条件；最后给出了该系统出现定常运动和混沌运动的数值结果。

In the continuous limit, the quantum one-dimensional extended Hubbard lattice model with half-filled band is transformed into the fermion field.

在连续化极限情况下把量子一维格点扩展Hubbard模型变换为连续的费米场。

The fractal code of the image consists of the parameters of the contractive transformation.

因此，一幅图像的分形编码就是寻找一个合适的压缩仿射变换，它的不动点是原始图像尽可能好的近似。

The PSE in the curve coordinate systems are solved by the numerical techniques developed efficiently in this paper. A normal transform is introduced, and there are enough much grids in the region between the critical layer and the wall, where the variation of the disturbance is the quickest. The finite-difference of governing equations with fourth-order accuracy in the normal direction is utilized in full regions including points close the wall, and is very important for accurately discreting equations.

对于曲线坐标系下的抛物化稳定性方程，文中发展了求解的高效数值方法：引进法向变换，使得在临界层与壁面之间的扰动量变化最快的区域有更多的法向网格点；导出包含边界邻域在内的完全四阶精度的法向有限差分格式，这对方程精确离散至关重要；采用全局法和局部法相结合的方法及其新的迭代公式，大大加速收敛并得到更精确的特征值。

The former applies to those situations that the formulas of two projections are simple and easy to find out the direct relation of the plane rectangular coordinate.

数值变换法应用范围较广，它可以避开较复杂的投影坐标公式的反解问题，求出两个不同投影平面场上点的对应关系。

In chapter 1,we find out a kind of two-parameter invariant cubic curve family of a certainquadratic system which is important one for studying the distribution of limit cycles.

第二章讨论一般的二次系统具有三次代数曲线同宿环的充要条件，针对问题，我们采用了具有双曲鞍点的二次系统的标准形，利用仿射坐标变换，我们把系统和曲线同时简化，使问题得到了完满解决。

Analysed existing dactylogram to collect detailed rules, commutation, dry to valid area, gray scale the respect such as deflection of wet, position undertook be discussinged deep to the influence of dactylogram picture quality, the is based on brim detail to nod information dactylogram picture quality that offers a kind to improve evaluates a method, the dactylogram image to be being collected undertakes quality is evaluated, the pretreatment that is image provides the dactylogram picture with higher quality.

分析了现有的指纹采集细则，对有效面积、灰度变换、干湿、位置偏移等方面对指纹图像质量的影响进行了深入的探索，并提出一种改进的基于边缘细节点信息的指纹图像质量评估方法，对采集到的指纹图像进行质量评测，为图像的预处理提供质量较高的指纹图像。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。