查询词典 mathematical

By means of both experiments and calculation to the mathematical model, the relation between construction of induction coil and profile of magnetic field as well as the meniscus shape of melt were researched systematically.

采用实验与建立数学模型进行计算相结合的方法对感应圈构造与磁感应强度的分布以及熔体成型形状之间的相互关系进行了全面、系统的研究。

Induction heating furnace is a complex delay system.Exact mathematical model is not easy to be established.

感应加热炉是一个复杂的非线性大滞后系统，很难建立一个精确的数学模型，用常规的控制方法难以得到满意的效果，而且人工调试比较困难，在扰动比较大的时候，就会远离设定值。

Induction is the most common method to solve mathematical problems.

化归是解决数学问题中最一般的原则。

Mathematical induction is an important method in mathematics.

数学归纳法是数学中一种重要的证明方法，也是中学数学一个非常重要的内容，用于证明与无穷的自然数集相关的命题。

Not considering the restriction of the depot s transporting ability in the existing achievement of emergency dispatch, consequently, this chapter establishes a sole-resource optimized dispatch model aimed at "the shortest dispatch time" which includes the constraint of transporting ability under time restriction firstly. Moreover, the chapter deduces the algorithm of the model by mathematical induction step by step. Secondl y, it simplifies the former model and gives a simpler sole-objective model and corresponding algorithm including the constraint of transporting ability. At last, on the basis of the improved model, this chapter discusses a two-phase programming model and a multi-objective programming model which are aimed at "the shortest dispatch time" and "the fewest number of mobilized depots" including the constraint of transporting ability under time restriction.

由于现有应急调运的研究成果中没有考虑到各物资供应点受运输能力的约束，因此本章首先建立限制期内以"应急调运时间最短"为目标且含有运输能力约束的单物资调运优化模型：并利用逐步递推法推导出具体的求解算法；然后，进一步地将此模型及算法进行简化，建立更加简单的含有运输能力约束的单目标优化模型：并且讨论其算法；最后，在改进的优化模型的基础上，讨论限制期内含有运输能力约束且以"调运时间最短"、"出动的供应点数目最少"为目标的双层规划及多目标规划的优化模型及解法。

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

The analysis is based on the mathematical induction.

我们的分析方式是以数学归纳法为基础。

In this thesis a mathematical model referring to the relationship between the case depth and carbon distribution by using a nonlinear regression. The electromagnetic characteristics in carburized materials were discussed. Results show that inductivity and magnetic inductivity depend on the carbon concentration in carburized layer. A relationship model between the electric, magnetic inductivity and carbon concentration was built.

结合渗碳材料的碳浓度和组织状态对电导率和磁导率的影响规律，建立了渗碳材料电导率和磁导率与碳浓度的关系模型，利用该模型及渗碳层深度和碳浓度分布关系的数学模型，建立了渗碳层深度与渗层电磁性能的关系，为实现对渗碳层深度的无损检测提供了可靠的理论与实验基础。

Current tuning is introduced, and the speed open-loop transfer function is established based on current closed-loop. A mathematical inequation about the speed open-loop transfer function is deduced, then the measured amplitude-frequency data is introduced in the inequation, thus the mathematic expressions about moment of inertia and mechanism time constant are obtained.

引入了电流校正环节，建立了基于电流闭环的速度开环传递函数，推导了关于该速度开环传递函数的数学不等式，再将实际测得的幅频特性代入此不等式中，得到了关于转动惯量和机械时间常数的数学表达式。

Using differential calculus knowledge to testify inequality, Calculus of higher mathematics is the core and calculus method of higher mathematics is typical of the whole mathematical method, the method is introduced for calculus ideas to solve the problem of finding an inequation, to make way for obtaining inequalities can be simple, the application of differential mid-value theorem and Taylor formula illustrate some of the inequality proof method.

运用微分学知识证明不等式；微积分是高等数学的核心，微积分思想方法是高等数学乃至整个数学的典型方法，微积分思想方法的引入为解决不等式证明的难题找到了突破，用来解不等式可使解题思路变得简单，文章应用微分中值定理及泰勒公式举例说明了部分不等式的证明方法。

You can do some assertiveness training.

你可以进行一些自信训练。

We were well on the path to making a rear-wheel-drive global platform," says Mays."

我们正致力于建立一个后轮驱动的平台，"Mays这样说道。"