不变

Feature of principal lines spatial distribution: detect the principal lines through edge detecting technology, and then divide the image of palmprint into blocks with same dimension, compute the mean and variance as feature; Feature of palmprint direction: divide the image into sub-images; compute the max angle of projection and coordinate of each sub-image, which stand for the direction and location of the line on the palm; Feature of moment invariants: compute the moment invariants of each sub-image and the whole image as feature.

掌纹主线空间分布特征：利用边缘检测技术检测出掌纹的主线，将图像分割成相同大小互不重叠的子图，提取每一个子图的均值和方差作为特征；掌纹线方向特征：将图像分成不重叠的子图，利用Radon变换求出每一个子图的最大投影角度和坐标，也就是子图内掌纹线的方向和位置，构造特征向量；掌纹不变矩特征：提取图像整体和分割后的子图的不变矩作为特征。

In the present paper, we shall show that there are many elliptic invariant tori of the equation for a given analytic potential which is not necessary to be constant.

在这篇文章中，证明对于给定的解析势函数，不一定是常数，方程存在许多椭圆不变环面，与 Kuksin 和 Poschel 的文章不同的是，不变环面上承载的是高频的拟周期解。

At the time of dealing with the fourth problem, we try calculus of variation of spending, move route transform into a line issue of the victory, Utilize Euler formula , ask and publish time running orbit after a little while most , confirm right route most, It's a pity that we can't get a satisfactory answer in a short time.

得到如下结果：在水流速度不变的情况下，年第一名的游速为，与方向与X轴成，如竞渡者以行进，则与X轴成，用时分秒，竞渡者若与对岸垂直游不可能达到终点；在不同区段内水流速度不变的情况下，竞渡者以折线前进，用时约为；在同一区段内水流速度变化情况下，竞渡者以曲线前进，用时约为。

This paper analyses the influence of scale factor on moment invariant features in discrete,constructs a new moment invariant with both scale,translation and rotating invariance.

分析了在离散状态下比例因子对不变矩特征的影响，构造了一种新的不变矩，使其具有平移、旋转和比例因子的不变性。

Tent, for the nomad in Chinese history, has been muchly constant as it is the best architecture for the nomad in working. Periodic or aperiodic graze has led in instability of residence and working facility, and tent becomes the sole selection in habitation for thousands of years due to its effective collection and transportation during regular and constant migration.

同样我们再看中国历史上的游牧民族居住的帐篷，之所以长久不变，是因为这是最最适合游牧民族生产作业的建筑功能形式，他们定期或不定期的放牧造成了住所和生产工具的流动性，在经常性的、不断迁徙情况下，帐篷这一简单有效的居住形式因其便于折叠收藏及运输，自然就成了其几千年来不变的居住建筑唯一选择。

In the first part, the thesis firstly constructs the production possibility sets deduced from constant, nonincreasing, nondecreasing and nondetermined returns to scale. Based on the above point, the thesis systematically deduces the models of DEA which evaluate production efficiency for exogenously fixed inputs and the models of ADEA (Allocative Data Envelopement Analysis) which evaluate cost, revenue, profit efficiencies and allocation efficiency in production possibility sets, and then discusses the solution properties of these mathematics models.

在第一部分中，首先以生产规模收益率不变、非增、非减和不确定四种情形下的生产可能集的构成为出发点，系统地归纳出在这四种生产可能集上评价具有固定不变输入或输出生产有效性的DEA模型及其相应情形下评价生产成本、收入、利润和生产配置有效性的ADEA模型，并讨论了这些数学规划模型解的性质。

First, the proposed scheme uses contourlet transform to extract multidirectional and multiscale texture information, and then obtains the feature points invariant to the affine transformation from the low and middle directional subbands by Harris-Affine detector. Second, the feature regions are adaptively computed by the feature scale of the local structure and normalized by U transform. The watermarking is embedded adaptively in those characteristic regions which are normalized. Finally, by vector quantization, several copies of the watermark are embedded into the no overlapped local feature regions in different directional subbands.

首先，用Contourlet变换提取出多尺度、多方向的纹理信息；再用Harris-Affine检测算子从变换域的中、低频方向子带中提取出仿射不变特征点，结合自适应局部结构的特征尺度确定特征区域，并用U变换对其归一化处理，水印就自适应地嵌入到归一化后的区域中；水印嵌入采纳矢量量化的策略，将水印信息重复嵌入到不同方向子带、多个不相交的局部仿射不变特征区域。

I do not have any prevision about your arrival.

我一直想找一样永远不变的东西来守住它，可我又不知道，这世界上究竟有没有永远不变的东西。

The results show that the vertical sintering speed changes notably with the proceeding of sintering process. After ignition and thermal retardation the bed permeability deteriorates and the sintering speed decreases notably because of the progress of physical chemistry reaction, formation and broaden of combustion zone, and formation of overwet zone. In about 25 min, the over wet zone vanishes, so the bed permeability meliorates and the speed arises rapidly.

结果表明：垂直烧结速度并非固定不变，而是随着烧结过程的逐步进行发生显著变化；点火保温后，随烧结物理化学反应的进行，燃烧带逐渐形成并变宽且产生过湿现象，导致料层的透气性显著变差，烧结速度显著下降，直至约25 min后过湿层完全消失，透气性变好，烧结速度迅速上升。

The original video is spitted into a series of frame groups,for each frame in the group,the points of contour shape are described by MPEG-7,and taking advantage of hash function to calculate the keys between those points in the 1D- DFT transform domain and the watermark signals.

在该算法中，原始视频数据被分割成等帧数的视频组，利用MPEG-7的轮廓编码计算每个视频帧的主要物体轮廓坐标点集合；接着通过傅立叶变换得到该帧轮廓点形状不变量，利用哈希的方法计算水印信号并将这些不变量的有效值作为密钥之一；再对整个视频组的轮廓点进行傅立叶变换，得到其时间轴上的有效不变域，将水印信号嵌入在这个不变域的中频部分以确保了水印的鲁棒性。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。