数学分析

For the dynamic system of discrete coupled and nonlinear three phase voltage source PWM rectifier, the cycle switch average operator is introduced to transform the discrete system into continuous and the small signal perturbation method is used to transform the nonlinear system into linear, the small signal dynamic mathematical models are set up.

中文摘要：针对三相电压型PWM整流器这个离散的、耦合的、非线性的动态系统，引入开关周期平均算子将离散的系统变换为连续的系统，应用小信号扰动法将非线性的系统化解为线性的系统，进而分析系统的小信号动态数学模型。

For the dynamic system of discrete coupled and nonlinear three phase voltage source PWM rectifier, the cycle switch average operator is introduced to transform the discrete system into continuous andthe small signal perturbation method is used to transform the nonlinear system into linear, the small signal dynamic mathematical models are set up.

中文摘要：针对三相电压型PWM整流器这个离散的、耦合的、非线性的动态系统，引入开关周期平均算子将离散的系统变换为连续的系统，应用小信号扰动法将非线性的系统化解为线性的系统，进而分析系统的小信号动态数学模型。

Based on the discrete distribution characteristics of coil turns, the position error mathematical models of PCB air-core coils are set up and then analyzed.

该文基于线匝的离散分布特性建立了PCB空心线圈位置误差的数学模型，并进行了详细分析。

Through careful analysis of the mathematics model of daily dispatching optimization of the cascade hydropower station, a new method based on the combination of two dimensional dynamic programming and discrete differential dynamic programming is proposed.

通过仔细分析梯级水库日优化调度的数学模型，提出了一种基于二维动态规划和离散微分动态规划相结合的混合求解策略，该策略理论上严谨，计算时间比较短，能满足日常调度的需要。

This paper introduces the food refrigerated theory and the basis of the current industry refrigerated developments in the situation; And then in the long cylindrical-shaped food heat conduction process and the mathematical model using the method of differential thermal conduction equations for discrete, Programming come through long cylindrical-shaped food cooling process numerical solution; After further analysis of numerical solution of the test results; Finally, the impact of the cooling process food all relevant factors, such as moisture content, wind speed and temperature of the cooling medium for in-depth research, while comparing the different shapes of food to food cooling process.

本文首先介绍了有关食品冷冻冷藏的基础理论和目前冷冻冷藏行业的发展的发展概况；然后研究了长圆柱状食品热传导过程的数学模型并利用差分的方法对热传导方程进行离散，通过编程得出长圆柱状食品冷却过程的数值解；之后再分析解对数值解的结果进行验证；最后对影响食品冷却过程的各相关因素，如含水率、风速和冷却介质温度等进行了深入的研究，同时又对比了不同形状的食品对食品冷却过程的影响。

Results To construct several combining multiple regression mathematical models that use the arrested extent of epiphysis of sternal end of clavical and six joints to assess the chronological age of living subjects in Chinese Han female teenagers, and establish some Fisher's discriminatory analysis equations which are used to determine whether the chronological age of Chinese Han female teenagers has been to 14, 16 and 18 years old or not.

结果 建立了我国汉族女性青少年利用锁骨胸骨端及6大关节骨骺闭合程度联合推断活体年龄的多元回归数学模型，推导出判定我国汉族女性青少年是否已满14、16和18周岁的Fisher's两类判别分析方程。

To make occurrence degree prediction, single factor regression algorithms, stepwise regression algorithms, discriminatory analysis, Markovian model, fuzzy mathematics theory and Back propagation neural network algorithms are studied and models are builded.

将筛选出的主要气象因子作为预测因子，分别用单因子回归预测法、逐步回归预测法、判别分析预测法、马尔柯夫链预测法、模糊数学预测法与神经网络预测法建立了关中地区小麦吸浆虫的发生程度的预测模型。

Fully depending on the math, modern mainstream economists have a suit of unitive linguistic system and the common discourse foundation. And based on such an artificial linguistic system, economic discursion and analysis show more logically precious and accurate advantages than natural language.

充分依赖于数学这样一种符号化的诉求，现代主流经济学家不仅拥有了一套统一的语言体系及共同的话语基础，而且借助于这样一种人工语言系统，又使得经济学的推理与分析过程呈现了比自然语言更具逻辑严谨性和精确性的优势。

In this paper, the change rule of inner oil temperature in wet multiple disk brake is studied when braked. Mathematics model on unsteady state heat transfer is established in wet multiple disk brake On the basis of theory and experiment research, which will provided theory ground for design and choice type on wet multiple disk brake.

本论文在理论与试验研究的基础上，研究与分析了湿式多盘制动器在制动时内部油温的变化规律，建立了湿式多盘制动器整体非稳态散热的数学模型，为湿式多盘制动器的设计与选型提供了理论依据。

In chapter 2, the present distribution parameter of fluid pipe are analysed and compared with each other in both time domain and frequency domain. One of them is considered to be most suitable for theoretical analysis of hydraulic system.

第二章分别从时域和领域两个角度，对现存的各种流体管道数学模型进行了分析和对比，从中选择适合本课题进行研究的流体管道模型。

Singer Leona Lewis and former Led Zeppelin guitarist Jimmy Page emerged as the bus transformed into a grass-covered carnival float, and the pair combined for a rendition of "Whole Lotta Love".

歌手leona刘易斯和前率领的飞艇的吉他手吉米页出现巴士转化为基层所涵盖的嘉年华花车，和一双合并为一移交&整个lotta爱&。

This is Kate, and that's Erin.

这是凯特，那个是爱朗。