坐标变换

InSection 2,we give several sufficient conditions for the existence of one solution,multiplesolutions and infinitely many solutions of the Sturm-Liouville bvps via the generalizedpolar coordinates.Then in Section 3,the existence of positive solutions are proved undersuperlinearity,sublinearity and many other conditions by a fixed point theorem in cones.Our results have generalized those in many articles.A detailed discussion of periodic solu-tions of a kind of functional differential equations with high-order Laplacian-like operatorcan be found in Section 4 and this subject has not been studied before.

在第二节，我们定义了一种新的坐标变换-广义极坐标，并利用它讨论了p-Laplacian算子和Laplacian-型算子的Sturm-Liouville边值问题，分别得到了存在一个解、多个解、无穷多个解的多个充分条件；第三节研究p-Laplacian算子的Sturm-Liouville边值问题正解的存在性与多重性，采用的是锥上的不动点定理，全面推广了这一方面已有的结果；对目前研究较少的高维Laplacian-型算子及带有Laplacian-型算子的泛函微分方程的周期解问题，我们在第四节做了一些研究，这也是拓扑方法的一个应用。

From Maxwell's equations, with material constitutive relation of optically active crystal and boundary conditions of electric field on the boundary between isotropic media and crystal, through coordinate transformation, the formula of the direction of refracted wave for arbitrary direction incident monochromic plane wave was derived. Furthermore, based on the unit vector of direction of refracted wave, eigen waves of electric field, electric displacement vectors and direction of energy flow can be easily obtained.

从麦克斯韦方程组出发，结合旋光晶体的物质方程以及单色平面波从各向同性介质入射到晶体界面时电场的连续性边界条件，通过晶体主轴坐标系和界面坐标系的坐标变换，推导了任意入射方向的单色平面波在晶体界面上的折射方向的求解公式，进而利用所得的折射方向求解晶体中折射波的电场本征模、电位移矢量本征模和光线方向。

The interfacial stability of the model was studied by Chebyshev pseudospectral method for different basic velocity profiles.

并用Chebyshev配点法研究了不同速度剖面自由射流的界面稳定性问题。利用非线性的坐标变换。

Firstly, this paper based upon coordinate transformation in vector space, the resolution principles of ship's swinging in three rotative axes of a hull – mounted array sonar are developed. The analytical results are used as the rules to control and stabilize the attitude of the array sonar so as to isolate the swinging of the ship.

本文首先根据矢量空间坐标变换的原理，分析了船舶摇摆运动在声纳基阵转动轴上的分解原理，得出了控制和稳定声纳基阵姿态不受船舶摇摆影响时所需的控制规律。

The method is based on a variable structure to control the SVC, wherein, the variable structure control method comprises two aspects of the unbalanced load equalization compensation and the parameter control of a PI controller, wherein, the unbalanced load equalization compensation adopts the SVC compensation susceptance computational method which is based on the synchronous rotation reference coordinate transformation of a virtual symmetrical three-phase system; meanwhile, in the stabilization control of the system voltage, the ant colony algorithm optimization method is adopted to real time adjust and to optimize the parameter kp and ki of the PI controller.

本发明公开了一种静止无功补偿器的不平衡补偿和蚁群优化方法，基于变结构对静止无功补偿器SVC进行控制，其中变结构控制方法包括不平衡负荷平衡化补偿和PI控制器的参数控制两个方面，其中不平衡负荷平衡化补偿采用基于虚拟对称三相系统的同步旋转参考坐标变换的SVC补偿电纳计算方法；同时在系统电压稳定控制时，采用蚁群算法优化方法，对PI控制器的参数kp、ki进行实时调整、寻优。

The speed-sensorless vector control and the identification of motor parameters in this paper are the two novel research of vector control.Using asynchronous machine's mathematic model in three-phase static reference frame, this paper has derived it's mathematic model in two-phase static reference frameand in two-phase rotating reference frame, and got the coordinate transformance formulus based on the constant magnetic force and power force, by compared different field orientation methods, we can find that field orientation at rotor field can realize the decoupling of the stator current flux component

无速度传感器矢量控制和电机参数辨识是矢量控制的两个新的研究方向，本文利用异步电机在三相静止坐标系下的数学模型推导出两相静止坐标系、两相同步旋转坐标系下的数学模型，根据磁动势守恒和功率守恒的原则，得出各坐标变换公式；通过不同磁场定向方式的比较发现，异步电机按转子磁场定向时定子电流励磁分量和转矩分量可以比较方便地实现解耦。

Firstly, this thesis makes an introduces on the developement of PMSM servo system based on DSP. According to the control theory of AC PMSM servo system, this paper analyzes the coordinate transformation, the rotor magnetic field orientation and the current control strategy of AC servo system. The control strategy is i_d=0. The system is orientates towards rotor magnetic field. Then the mathmatic models of PMSM in d-q coordinate are set up.

本文首先对基于DSP的永磁同步电机伺服系统的发展概况进行了介绍；根据永磁同步交流伺服系统的基本控制理论，分析了交流伺服系统坐标变换原理、常用的磁场定向方式及电流控制策略，并给出i_d=0电流控制策略及永磁同步电机按转子磁场定向的控制方式，从而建立永磁同步电机d-q坐标系下的数学模型。

According to investigate the relation of coordinate system in CNC lathe , this paper pointed out the coordinates transfer's equation and analyzed several methods of presetting cutter, and introduced to using this function well.

通过数控车床坐标系传递关系的研究，总结出坐标变换公式，就三种不同对刀方法的应用差别进行比较分析，介绍我们的认识，并说明如何针对不同系统的特点来灵活使用它们。

By means of presupposing the frequency in dual d-q coordinate transformation matrix the detection of specific-order harmonic is realized; by way of adding forecasted compensation angle into detecting link, the time-delay brought by digital controller and inverter is compensated.

该方法通过预设双d-q坐标变换矩阵中的频率，实现了对特定次谐波的检测，通过在检测环节中加入预测补偿角，补偿了数字控制器和逆变器带来的延时。

Besides converting the topographies to flat bottom, the transforms also change the distribution of forcing.

数值模拟和外海实验发现内潮多从地形的波折处产生，这从本文得到的坐标变换之后的强迫源的强度分布中可以得到解释。

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。