Its advantage is that absolute decoupling for the nominal responses of system outputs can be implemented , and moreover , the controller parameters can be tuned on - line in a monotonous manner to cope with the plant unmodelled dynamics , so that significant decoupling regulation can be achieved 其突出优点是能够使标称系统各路输出响应之间完全解耦，并且能够在线以单调的方式整定控制器参数来适应对象的未建模动态，从而实现显著解耦调节。
The principle of i d = 0 control method is analyzed systematically based on vector control technique of pmsm . this thesis points out that vector control is more a static decoupling than a full decoupling . in fact , the i d = 0 control method of pmsm , which can realize torque linearization control , is a vector decoupling control 主要内容概括如下: 1 .对永磁同步电机的矢量控制技术进行了系统的分析,深入地剖析了i _ d = 0控制的机理,指出矢量控制只是一种静态解耦,并非完全解耦,永磁同步电机的i _ d = 0控制实质是一种矢量解耦控制,可以实现转矩线性化控制。
Simulations for these two conditions prove validity of theoretical analysis . on the basis of this scheme , a new speed adjustment strategy about vector control of doubly fed motor based on rotor current vector fixing is given . it introduces the closed - loop of stator excitation current to the system , which increases two adjustment channels : speed and excitation adjustment 经理论分析可知，该方案中，由于转子电流与磁链无法实现完全解耦，故仅在亚同步工况下有效，在超同步时则会因为调速系统不能自动校正转子磁链幅值变化引起的横向电流而使系统失去控制，无法达到稳定状态。
For the regular curves , we find two killing fields for the purpose of integrating the structural equations of the p - elastic curves and express the p - elastica by quadratures in a system of cylindrical coordinates . for the star - like affine curves , we solve the euler - lagrange equation by quadratures and reduced the higher order structure equation to a first order linear system by using killing field and the classification of linear lie algebra sl ( 2 , r ) , sl ( 3 , r ) and sl ( 4 , r ) . we solve the centroaffine p - elastica completely by quadratures 对于正则曲线的情形，我们发现了两个用于求解p -弹性曲线的结构方程的killing向量场并用积分将p -弹性曲线在一个柱面坐标系中表示出来，而对仿射星形曲线的情形，我们用积分方法解出了欧拉-拉格朗日方程，利用killing向量场及线性李代数s1 ( 2 ， r ) 、 s1 ( 3 ， r )和s1 ( 4 ， r )的分类将高阶结构方程降为一阶线性方程，因此我们用积分完全解出了中心仿射p -弹性曲线。
Although it can dramatically improve the dynamic peculiarity in the theory , the vector control approach not only makes the complex reference frame changes , but also rely on the parameters of the motor to a large extent . at the same time , the completely uncoupling in the dynamic process is not ensured and the effectiveness of the torque control is reduced 尽管矢量控制方法从理论上可以使交流传动系统的动态特性得到显著改善，但实现时要进行复杂的坐标变换，而且对电机的参数依赖性很大，难以保证动态过程完全解耦，使转矩控制效果打了折扣。
General compressing technologies are not proper in some circumstances for the receivers are always required to decompress the data completely to manupulate the original data ( querying , validating etc . ) . the embedded document structure of xml also makes it difficult to perform access control because the traditional file level access control systems could not fulfill the requirement of element or attribute level access control . in the paper we first present a scheme for xml - based data exchange which is an xpath - query - friendly compressor for xml 压缩技术是提高交换效率的一种方法，但接收方需要对压缩文档完全解压才能够执行进一步的操作，在很多应用中这种方式并不适用，这就提出了如何在高效压缩的同时在压缩后的xml文档上进行查询等操作的问题；另一方面，由于xml文档的层次结构的特殊性，传统的文件级别的访问控制已经不能适应在元素、属性的级别上进行访问控制的需要，所以对只需要访问部分xml文档内容的用户进行有效的数据访问控制也是xml数据访问控制面临的一个问题。
