基本类

Quadratic algebraic function fields are studied here.Fundamental units forseveral types of such fields are determined explicitly.

本文研究了二次代数函数域，明显决定了几类实二次函数域的基本单位，决定了多类二次函数域的理想类数的下界，给出了类。。。

This dissertation investigates the construction of pseudo-random sequences (pseudo-random numbers) from elliptic curves and mainly analyzes their cryptographic properties by using exponential sums over rational points along elliptic curves. The main results are as follows:(1) The uniform distribution of the elliptic curve linear congruential generator is discussed and the lower bound of its nonlinear complexity is given.(2) Two large families of binary sequences are constructed from elliptic curves. The well distribution measure and the correlation measure of order k of the resulting sequences are studied. The results indicate that they are "good" binary sequences which give a positive answer to a conjecture proposed by Goubin et al.(3) A kind of binary sequences from an elliptic curve and its twisted curves over a prime field F_p. The length of the sequences is 4p. The "1" and "0" occur almost the same times. The linear complexity is at least one-fourth the period.(4) The exponential sums over rational points along elliptic curves over ring Z_ are estimated and are used to estimate the well distribution measure and the correlation measure of order k of a family of binary sequences from elliptic curves over ring Z_.(5) The correlation of the elliptic curve power number generator is given. It is proved that the sequences produced by the elliptic curve quadratic generator are asymptotically uniformly distributed.(6) The uniform distribution of the elliptic curve subset sum generator is considered.(7) We apply the linear feedback shift register over elliptic curves to produce sequences with long periods. The distribution and the linear complexity of the resulting sequences are also considered.

本文研究利用椭圆曲线构造的伪随机序列，主要利用有限域上椭圆曲线有理点群的指数和估计讨论椭圆曲线序列的密码性质——分布、相关性、线性复杂度等，得到如下主要结果：(1)系统讨论椭圆曲线-线性同余序列的一致分布性质，即该类序列是渐近一致分布的，并给出了它的非线性复杂度下界；(2)讨论两类由椭圆曲线构造的二元序列的"良性"分布与高阶相关性(correlation of order κ)，这两类序列具有"优"的密码性质，也正面回答了Goubin等提出的公开问题；(3)利用椭圆曲线及其挠曲线构造一类二元序列，其周期为4p(其中椭圆曲线定义在有限域F_p上)，0-1分布基本平衡，线性复杂度至少为周期的四分之一；(4)讨论了剩余类环Z_上的椭圆曲线的有理点的分布估计，并用于分析一类由剩余类环Z_上椭圆曲线构造的二元序列的伪随机性；(5)讨论椭圆曲线-幂生成器序列的相关性及椭圆曲线-二次生成器序列的一致分布；(6)讨论椭圆曲线-子集和序列的一致分布；(7)讨论椭圆曲线上的线性反馈移位寄存器序列的分布，线性复杂度等性质。

Based on the principle of Otsu method with maximum variance between threshold algorithm of image segmentation, an improved method derived from Otsu algorithm is put forward, which combines interclass distance with intraclass distance, a partial recursive algorithm is used to search optimum threshold.

基于最大类间方差阈值图像分割算法的基本原理，然后结合目标与背景两类之间间距和类内距离对图像分割效果的影响，提出了一种改进的最大类间方差法，运用递归思想局部搜索图像的最佳阈值。

This paper briefs the basic principles of " transitive closure " cluster analysis based on fuzzy equivalent relation and fuzzy ISODATA cluster analysis based on soft division technique, and advances a classification and recognition method by combining K-L transformation and the two fuzzy cluster methods above, which makes full use of the advantages of both cluster methods.

介绍了基于模糊等价关系的"传递包"聚类和基于软划分的模糊ISODATA聚类2种模糊聚类分析方法的基本原理，充分利用2种方法的优点，提出了一种将K-L变换与上述2种模糊聚类方法相结合的分类识别方法。

The rules of photo bioactivities are: Without illumination, the tested xanthene derivatives showed almost the same level of inherent toxicity to the same organism, which showed the inherent toxicity of xanthene derivatives were primarily dependent on the structure of parent molecule. Upon illumination, the photosensitizers showed obvious phototoxicity to all organisms. The xanthene derivatives showed stronger phototoxicity to Gram-positive bacteria. With the increasing number of halogen substituents, the singlet oxygen yields increased and the phototoxic activity increased too.

呫吨类化合物的生物活性的变化规律为：未经光照的条件下，呫吨类化合物的对同种待测微生物的固有生物活性基本相同，说明固有毒性可能主要决定于化合物分子的母核结构，其卤素取代基团对其影响较小；经实验光源照射下，所测MLC值明显低于未经光照条件下的值，表明呫吨类化合物对三种微生物的光敏活性明显强于对其相应的固有活性；呫吨类化合物对革兰氏阳性菌能发挥较大的光敏活性。

The intake of fats,protein was higher than drls,while the carbohydrate vitamin a,vitamin b2 and some minerals was not sufficient to meet the demand of body.of all the 836 officers,there were many more people whose body mass was excessed the standard.and there were some people who had hypertension,hyperglycemia,hyperlipemia,hyperuricemia and fatty liver.conclusion the total energy of food can meet the need of the officers,but the food structure is not reasonable.therefore,it is necessary to adjust the food structure,increase the intake of grains,beans,milk,fruits and vegetables,decrease the intake of fat,salt and alcohol and diversify the food items.

食物摄入总热量基本符合要求，但分布不够合理。脂肪和蛋白质的摄入量偏高，碳水化合物摄入过低；维生素a、维生素b2及钾、钙、镁的摄取量偏低；836名高职在职干部体质量超标较为严重，部分患有高血压、高血糖、脂肪肝、高脂血症及高尿酸血症。结论食物摄入总能量基本符合要求，但饮食结构欠合理。建议调整饮食结构，适当增加谷类、豆奶类食物及果蔬类食物摄取，减少脂肪、食盐及酒精的摄入，提倡食物品种多样化。

"In the early 1970s it was discovered that these particles are made up of several types of even more basic units, named quarks, which, together with several types of leptons, constitute the fundamental building blocks of all matter."

1970年代初，发现这些粒子由几类称为夸克的更基本的单元组成。夸克与几类轻子一起组成了所有物质的基本结构单位。

"In the early 1970s it was discovered that these particle s are made up of several types of even more basic units, named quarks, which, together with several types of leptons, constitute the fundamental building blocks of all matter."

1970年代初，发现这些粒子由几类称为夸克的更基本的单元组成。夸克与几类轻子一起组成了所有物质的基本结构单位。

"In the early 1970s it was discover ed that these particles are made up of several types of even more basic units, named quarks, which, together with several types of leptons, constitute the fundamental building blocks of all matter."

1970年代初，发现这些粒子由几类称为夸克的更基本的单元组成。夸克与几类轻子一起组成了所有物质的基本结构单位。

With this measure, a new method for calculating the minimum embedding segment dimension of a linear segment sequence is proposed. With this method, the MESD of the linear segment representation of a real financial time series is calculated.

该方法实现了对时间序列的基于基本变化形态的合理分割，保证转换后的每一个符号都能代表一个基本的、相对独立的变化模式，为最终挖掘结果的有效性和可视化提供保证；同时，针对数据挖掘数据量大，对算法的计算效率和在线性能要求高的特点，提出了一个实现时间序列分段线性化的增量式更新算法；并利用神经网络模糊聚类算法实现了完全数据驱动的在线聚类分析。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。