查询词典 two-dimensional distribution

Suppose is two-dimension random variable, for arbitrary real value ,call distribution function for two-dimension random variable or unity distribution function .

Definition 3.2 设是二维随机变量，对于任意实数，称二元函数为二维随机变量的分布函数，或称为的联合分布函数。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastocysts followed by fusion of cytoplasm and nucleus and cleavage in vitro. During the fusion of cytoplasm, the DNA methylation levels of the fused embryos are as high as these of two-cell diploid embryos in vivo Then the embryos are rapidly demethylated when the nucleus begin to fuse, resulting in the lowest DNA methylation levels when the nucleus are fused completely. After that, the DNA methylation levels of the fused embryos are gradually increased until the morula stage. However, whereas an asymmetric distribution of DNA methylation is established in vivo-derived blastocysts with a higher methylation level in the inner cell mass than that in the trophectoderm, we can not detect the asymmetric distribution in most in vitro-derived tetraploid blastocysts.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在桑葚胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

Tetraploid embryos could be produced by electrofusion at the stage of two-cell embryos, which could develop to blastcysts fellowed by fusion of cytoplasm and nucleus and cleavage in vitro.After fusion of cytoplasm, the DNA methylation levels of the fused embryos was very high as well as two-cell diploid embryos in vivo.Then the embryos was rapiddly demethylated when the nucleus begin to fuse, resulting the lowest DNA methylation levels when the nucleus fused completely.After that, the DNA methylation levels of fused embryos were gradually increased until the blastocysts stage.However, whereas an asymmetric distribution of DNA methylation was established in an vivo-derived blastocysts with a higher methylation level in the inner cell mass than in the trophectoderm, in most vitro-derived tetraploid blastocysts, we can not detect the asymmetric distribution.

结果表明：利用电融合方法制备的小鼠四倍体胚胎在体外培养体系中经历细胞质融合、细胞核融合及细胞继续分裂发育直到囊胚期的过程，在细胞质融合的时候胚胎卵裂球同体内体外培养二倍体胚胎一样，呈现高度甲基化状态；在细胞核开始融合的时候，甲基化水平急速下降，在细胞核完全融合的时候甲基化水平达到最低点；随着胚胎继续分裂，胚胎甲基化水平逐渐增加，在囊胚期甲基化水平最高；但是囊胚期四倍体胚胎内细胞团同滋养层细胞甲基化荧光信号没有差别，这与体内体外培养二倍体囊胚内细胞团细胞甲基化荧光强度高于滋养层细胞甲基化荧光强度不同。

The primary work of this paper includes: 1 The general process and the fundamental theory of genetic algorithm is introduced systematically, which is also be applied to an example; 2 The penalty function method and the constraint tournament method are introduced in the paper, which are used to process the constraint limit. Via analyzing the basic principle of NSGA-II ,which is elaborated in the paper, the fast non- dominated sorting method, congestion distance and its comparison operator, the elite strategy and the main process of NSGA-II is researched particularly. 3 Via modeling the fire distribution problem, the model is computed by the algorithm of NSGA-II, which is combined with both the penalty function method and the restraint league tournament method The optimization of two goals are also realized in the paper. The results derived from the VC++6.0 indicate that, two algorithms both have the high convergence, simultaneously the Pareto optimal solution also maintain the variety of distribution.

本文所作的主要工作如下：系统地介绍了遗传算法的一般流程和基本理论，并应用于一个函数优化的实例；研究了用于处理约束限制的罚函数法和约束联赛法，论述了NSGA-II的基本原理，并对其提出的快速非支配排序法、拥挤度及其比较算子、精英策略及NSGA-II的主要流程作了详细的研究；建立了火力分配问题的模型，并将NSGA-II算法分别与罚函数法和约束联赛法相结合对该模型进行了计算，实现了对两个目标的最优化；用VC++6.0编程计算后所得的结果表明，两种算法均具有很好的收敛性，同时Pareto最优解也保持了好的多样性分布。

In this paper, the statistical characteristics of one plane and one helicopter's RCS dynamic measurement data are studied by using the χ^2 distributing, log-normal distribution and Rayleigh distributing model, along with the Kolmogorov fit test to goodness, the fitting results in some notableness level are acquired by using the three models for different aspect angles for two targets, and the degree of freedom distribution of χ^2 model in all aspect angles is obtained for two targets' RCS data.

文中以某歼击机和直升机为对象，应用χ^2分布、对数正态分布和瑞利分布模型，以及Kolmogorov拟合优度检验方法，研究其RCS动态测量数据的统计分布特征，得到了在一定显著性水平下，两种目标在不同视向角下对三种模型的拟合效果，同时得到应用χ^2分布拟合时模型半自由度随视向角的分布情况。

Based on the composite bounded reservoir model with two porous media, the Laplace solution of dimensionless pressure distribution under inner boundary condition (considering the wellbore storage and the skin effect) has been studied, and through analyzing the structures and interrelations of Laplace solution, the correlations with usual composite, two porous media and homogeneous reservoir pressure distribution have been found.

针对双孔介质复合封闭储层模型，研究了两种内边界条件(是否考虑井筒储存和表皮效应)下的变流率问题的无因次内、外区储层压力分布的Laplace空间解，在深入剖析了解的结构和相互联系的基础上，找出了它与常见的复合、双孔、均质储层压力分布间的相互关系。

Suppose is two-dimension random variable, call the probability distribution of measuremarginal distribution on for ; the probability distribution of measure Y marginal distribution on Y for .

Definition 3.6 设是二维随机变量，称分量的概率分布为关于的边缘分布；分量的概率分布为关于的边缘分布。

Suppose is two-dimension random variable, call the probability distribution of measure X marginal distribution on X for ; the probability distribution of measure Y marginal distribution on Y for .

Definition 设是二维随机变量，称分量的概率分布为关于的边缘分布；分量的概率分布为关于的边缘分布。

Among n web pages, access probability increment will decrease from the first web page to nth web page. Web pages above n will be accessed less frequently then ever. We analysed a Web server log and two proxy server logs. Analysis mainly focus on Web page request distribution, Web static document size distribution, Web static document access distance distribution, Web static doment access intertime distribution.

对一个典型的Web服务器和两个代理服务器的日志进行了分析，并将Web页面请求分布、Web静态文档大小的分布、Web静态文档的访问距离的分布、Web静态文档访问间隔时间分布同既有文献的结果进行了对比，有些结论是相同的，有些不同，可以视为我国WWW访问所特有的访问特性。

Through field observations and sampling, by referencing to other documents and information, with correlation analysis and principal component analysis as mathematical tools, we know that: the distribution of the number of birds has close relations with density of zoobenthos and ratio of water area, the correlation coefficient of the distribution and the two factors are 0.916 and 0.745, the density of zoobenthos is the most direct reflection; Vegetation types , the coverage and water level may have relations with the distribution of the kind of birds, normally, middle and large volume birds need high vegetation and high coverage as their habitats, and waterfowl like deep water as their habitats; Human activities have low impact on the the distribution of the number of birds, but the activities have relations with all the other environmental factors.

通过实地的观测、采样，并结合其他文献的资料，以相关分析和主成分分析作为数学工具，得知：鸟类的数量分布和底栖生物密度、水域面积比例有着密切关系，鸟类数量分布与两者的相关系数分别为0.916和0.745，其中，底栖生物密度是鸟类数量分布的最直接反映；植被类型、植被盖度和水位可能与鸟类的种类分布有一定关系，通常体积中、大型的鸟类需要较高的植被高度，来作为自己的栖息场所，水禽需要水位较深的区域作为自己的栖息场所；人为活动对鸟类数量分布的影响不大，但对所有自然环境因子都有一定影响。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！