Continuous on-line adaptation of the rotor time constant in FOC induction machine system

Rotor time constant is an important parameter for the indirect lleld oraentateO control of mauc- tion motor. Incorrect rotor tittle constant value will cause the flux observer generating a wrong angu- lar orientation of the rotor field. A new approach serves for rotor time constant on-line adaptation by setting the stator current to be zero for a short period. A smooth eorrector is designed to prevent ab- normal detection result from making adaptation. Impact of zero current duration on detection error and rotor speed is analyzed by experiments.     

Direction and polarization estimation for coherent sources using vector sensors

A two-dimensional direction-of-arrival (DOA) and polarization estimation algorithm for coherent sources using a linear vector-sensor array is presented. Two matrices are first constructed by the receiving data. The ranks of the two matrices are only related to the DOAs of the sources and independent of their coherency. Then the source’s elevation is resolved via the matrix pencil (MP) method, and the singular value decomposition (SVD) is used to reduce the noise effect. Finally, the source’s steering vector is estimated, and the analytics solutions of the source’s azimuth and polarization parameter can be directly computed by using a vector cross-product estimator. Moreover, the proposed algorithm can achieve the unambiguous direction estimates, even if the space between adjacent sensors is larger than a half-wavelength. Theoretical and numerical simulations show the effectiveness of the proposed algorithm.     

环保型涂装前处理技术开发方向

随着国家对环保的重视程度日益加深,污染防治已成为几乎所有行业,尤其是工业领域急需解决的课题。而作为前瞻技术,环保型涂装前处理技术的开发将对涂装行业甚至汽车工业产生深远的意义,尤其是纳米陶瓷锆盐处理和硅烷处理技术的成功应用必将成为涂装前处理技术上的飞跃。     

基于企业服务总线的物流园区信息管理平台模型构建

采用一种与平台/编程无关的消息传递架构企业服务总线(ESB)构建物流园区信息系统平台架构,从而使物流园区能快速搭建敏捷的、按需应变的商业动态信息环境,使企业在市场上占据领先的竞争优势。     

Acquiring synonymous attribute phrases for named entities via online encyclopedia

In this work,an approach is proposed to acquire synonymous attribute phrases of named entities （NEs） from an online encyclopedia.Synonymous attribute phrases are the phrases that express the same attribute with different surface forms for a class of NEs.Specifically,the proposed approach is composed of three stages.Firstly,the entries related to a given NE class are automatically selected from an online encyclopedia.Secondly,attribute phrases are extracted based on the statistics of phrase frequency.Thirdly,synonymous attributes are identified in a pairwise manner through a classification framework combining multiple features.The proposed approach is applied on Baidu Baike,a Chinese online encyclopedia,for four different NE classes.Experimental results show that the approach obtains an average precision of 74％ and an average F-value of 65％ for the four NE classes.In particular,thousands of synonymous attribute phrase pairs are acquired for each class,which demonstrates the effectiveness of the proposed approach.     

用广义相量法求解动态电路强制响应

当动态电路的激励是时间函数时，求电路全响应的关键是强制分量的求解。通常采用设特解方式进行。本文针对一些常见激励，给出一种新的方法──广义相量法．从而将微分运算变换成相量的代数运算，使强制分量的求解得到简化．     

带对合范畴中态射的(1,…,i)—逆

在文[1]—[5]的基础上,本文给出了带对合范畴中态射的（l,…,i）—逆的定义,进一步得到了具有三重分解的态射f的f{1,2,3}、f{1,2,4}的具体表达式。     

连续分布时滞系统最优控制的广义正交多项式方法

本文介绍了广义正交多项式及其运算矩阵．应用广义正交多项式的展开式及运算矩阵，将连续分布时滞系统的最优控制问题转化为求解代数方程组，最后求出最优控制解。该方法有效且简单．     

广义逆A_(T,S)~((2))的表示、行列式公式及其应用

本文给出了任一复矩阵 A 的广义逆 A_(T,S)~(2)的多种表示及其分量的多种行列式公式,从而得到许多重要的广义逆 A~+,A_(MN)~+,A~(d),A~#,A_(L)~(-1),A_(L)~(+)的多种表示和行列式公式,特别是 A_(MN)~+和 A~(d)的两个更简单的表示式。     

动态利率模型估计方法的一个实证检验

在分析广义矩估计法和极大似然法原理和方法的基础上，采用上海证券交易所国债回购利率数据对这两种估计方法在动态利率模型估计上的实证效果进行检验．为使其检验结果具有可比性，运用蒙特卡罗法产生仿真回购利率路径，然后对利率模型参数进行二次估计，所得结果就可用于对比评价这两种估计方法．检验结果表明，两种估计方法都能够比较准确地估计长期平均利率θ值，同时都过高地估计均值回复参数；对于波动项参数σ^2和γ值，MLE法的估计均值和标准误差要优于GMM法；总体上MLE法的估计误差明显小于GMM法的误差．