查询词典 mathematical analysis

A simulation research is conducted on the example of six-phase double star winding shifted by 30°synchronous motor.In order to investigate the control algorithm of multilevel inverter , high harmonics as well as its problems, a mathematical model of the control algorithm based on the voltage space vector is built. For the first time, the principle along boundary is introduced to confirm the chosen switch state when many switch states are corresponding to the same vector. Simulation analysis and hardware realization are conducted with the combination of diode clamped three-level inverter and five-level inverter.

建立了基于空间电压矢量控制算法的仿真模型；仿真研究中采用对偶小矢量搭配改善中点电位波动的问题；针对多个开关状态对应同一待选矢量的问题引入&循边原则&确定被选择的开关状态；对过调制问题进行了相应的处理：结合二极管嵌位式三电平逆变器和五电平逆变器进行了仿真分析和硬件实现。

For a class of Shunt-wound Active Power Line Conditioner, based on analysis of mathematical model of system and target of control, the algorithm of fuzzy variable structure sliding mode control is presented. The control algorithm can avoid complicated calculation of harmonic electric current in traditional control algorithm, and realize the feedback control of electric current. The algorithm is simple and easily implemented.

针对一类并联型有源电网调节器在分析系统数学模型和控制目标的基础上，提出了模糊滑模控制策略，避免了传统控制方法中复杂的谐波电流计算，实现对电源电流的闭环控制，该算法简单、易于实现，仿真结果证实了变结构滑模控制的有效性。

Theoretical analysis of strip mills AGC had been processed and a three-DOF mathematical model of hydraulic screw-down system had been built,which was specified cylinder displacement and inner gap and adapt to varied control way.

对板带轧机自动厚度控制模型进行了理论分析，建立了三自由度轧机负载的液压压下系统的模型，将缸位移和内辊缝相区分，使其适用于不同的控制方式，进而对厚度计式控制模型、变形的厚度计式控制模型、动态设定控制模型进行了对比研究，指出轧机模数和轧件塑性系数分别对应于自动厚度控制系统的静态指标和动态指标，为控制过程中参数的选取提供理论依据。

In addition, the blank holding force that is required to avoid wrinkle and rupture during conical part deep drawing is researched. The necessity of reasonable blank holding force in pressing is expounded. From the view of mechanical analysis, the wrinkle critical condition of side-wall is derived for the first time by the stress state of side-wall, the main deformation region on blank. According to the critical condition of plastic instability for flange, side--wall, corner of punch on blank, The blank holding force in conical part deep drawing is divided into four different regions within its forming figure. The basic principle of reasonable blank holding force during stamping is summarized and provided. The mathematical model of reasonable blank holding force that avoids the wrinkle and rupture is established and verified by the finite element numerical simulation and the grid experiment method. The result shows that it is accurate and reliable.

此外，本文还研究了圆锥形件拉深成形过程中，随着拉深变形过程的进行，毛坯为避免产生起皱、破坏缺陷而对压边力的需求情况，阐明了圆锥形件拉深成形过程中压边力合理变化的必要性；由毛坯主要变形区悬空锥壁部分的受力变形情况，从力学分析的角度，首次推导得出了圆锥形零件悬空锥壁起皱失稳的临界条件；并根据主要变形区法兰、悬空锥壁及凸模圆角部分的塑性失稳临界条件，在其成形范围图中，将圆锥形件成形过程中的压边力划分为四个区域；总结并提出了圆锥形件成形过程中压边力合理变化的基本原则；建立了防止起皱、破坏缺陷产生的压边力合理变化的数学模式，并得到了有限元数值模拟及网格实验法的验证，证实了理论分析结果的正确性和可靠性。

In the analysis, simple models and mathematical approximations are introduced.

从理论预计与实验结果的接近来看，这种解释是有意义的。

It is important to understand technical talk as social talk, to recognize that mathematics and mathematical objects are not (to borrow terms from the anthropologist Clifford Geertz' analysis of speech) simply "concatenations of pure form,""parades of syntactic variations," or sets of structural transformations.

（为了认识到数学和数学对象并非是简单的'纯粹形式的并列联接'、并非仅仅是句法变换、或并非是一套'结构转换'，以社会谈论理解技术谈论是重要的

Based on the analysis of working process of ejection gun of rocket ejection seat ,the physical and mathematical models of interior ballistics of ejection gun were established and the interior ballistics parameters of a rocket eject seat were validated by test and calculation.

在分析火箭弹射座椅弹射动力系统的工作过程的基础上，建立了其内弹道的物理模型和数学模型，并对某型火箭弹射座椅弹射动力系统内弹道进行了试验验证与计算，试验所测膛内气体压力随时间变化曲线与计算曲线基本吻合，弹射过程最大压力pm、工作时间tg、出口压力pg和出口速度vg分别为24.20(24.57)MPa，157(155)×10-3s，22.27(21.83)MPa，16.61(16.59)m.s-1，各特征参数的计算值最大误差小于3%。

At First, the thesis researches the dynamic characteristic of servo valve, model of dynamical outfit about valve control unsymmetrical hydraulic ram, influence of the additional disturbing force and the systematic static error, on the base of analysis of fatigue testing machine system. Then the mathematical models of position control system and force control system are built. According to the principle of load-matching, the hydraulic dynamical outfit and power source system are designed and components are chosen. Then the correlative parameters of system model are calculated and the simulation study is carried out.

研究了伺服阀的动态特性、阀控非对称液压缸系统的动力机构模型、附加干扰力的影响以及系统静差，继而建立了位置控制系统和力控制系统的数学模型，并在此基础上计算系统相关参数，对系统进行了仿真研究，进一步分析了系统的稳定性和可控性。

This paper introduces DDA, the basic mathematical principles, and presents applications in the analysis of rockfalls and slope stability problems.

在本篇文章将介绍DDA的发展渊源、基本的数理背景以及在比较特殊的落石与边坡稳定问题分析上的应用。

In this paper,the mathematical model of the automotive semi-active suspensions is established based.on the niechanical analysis.

本文根据汽车半主动悬架的基本结构，通过力学分析建立了其数学模型。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。