矢量计算

A novel direction of arrival and polarization estimation of electromagnetic vector sensors mounted on the airframe is proposed based on biquaternion. The signal processing model for EM-sensor mounted on the airframe is made by biquaternion and then the eigenvalue decomposition of spectral matrix is obtained by means of the EVD of its quaternion adjoint matrix. The memory requirement for data is reduced, and more accurate estimation result is gotten by deducing the stronger orthogonality constraint between the sin- gal and noise subspaces on the field of biquaternion. The performance of the new algorithm is confirmed through numerical examples.

针对机载电磁矢量传感器阵列DOA和极化参数估计问题，提出了一种基于复四元数估计方法，该算法利用四元数建立机载电磁矢量传感器阵列信号处理模型，然后利用四元数联合矩阵的特征分解得到阵列数据相关矩阵的特征分解，一方面使得计算过程中数据的贮存量大大减少，另一方面通过推导得到信号子空间和噪声子空间在四元数域上的正交性从而使DOA和极化参数佑计的精度更高，仿真证实了本算法的有效性。

The theory of function approximation is used to establish the transient model of thrust vectoring with the data calculated.

利用该程序计算了某矢量喷管在不同的压比、面积比和几何偏转角下的200多种三维有粘流场，获得了矢量喷管的性能数据。

We show that the differences between the results of our approach and the previous for the axial vector and vector vacuum susceptibilities are large, while that for the tensor vacuum susceptibility is small.

结果表明，我们的方法在计算轴矢量和矢量真空磁化率时与以前的方法相比数值差别是很大的，而张量真空磁化率的差别不大。

In this paper, based on the analysis of the structure, movement principle and math model of PMSM, fundamental theories of vector control, coordinates transform and algorithm of space vector PWM are introduced and PI control, speed and position calculation methods are discussed.

本论文在分析了PMSM的结构、运动原理及数学模型的基础上，系统地阐述了PMSM交流伺服系统矢量控制的基本原理、坐标变换方法及空间矢量脉冲宽度调制波的生成算法，论述了PI控制算法和速度位置计算方法。

For aeronautical static converter then three-phase unbalanced load, made use of four-leg three-phase main circuit topology solution based on abc coordinates of the three-dimensional vector control, so that the switch to select the vector and duty more than a simple calculation, a significant reduction in the modulation of the complexity of the algorithm.

为解决航空静止变流器在不平衡负载情况下不能正常工作的问题，提出了三相四桥臂主电路拓扑解决方案，并采用基于abc 坐标系下的三维空间矢量调制，使开关矢量的选取和占空比的计算简单化，显著降低了调制算法的复杂性。

This paper analyzes the different deflexion angle of thrust vectoring influence on aircraft take-off performance according to the result of numerical simulation.

通过数值仿真探讨了推力矢量的偏转大小对起飞性能的影响，对不同推力矢量偏转下飞机起飞性能的仿真计算结果进行了分析。

Line Integral Convolution method is a powerful technique for representing directional information in vector field visualization.

矢量场可视化是科学计算可视化中的一个研究热点，基于纹理图像的流线积分算法可以清楚地描述矢量场的细节。

First,a formula to calculate the normal vector of any hyperplane is given and a mixing matrix recovery algorithm based on the normal vector of any hyperplane is proposed.

首先给出了m维超平面的法矢量的计算公式，提出了一个基于超平面法矢量的矩阵恢复算法。

Firstly, two covering hypersphere algorithms were proposed, referred to as minimum volume covering hypersphere algorithm and moving medium centers covering hypersphere algorithm, to heuristically and rapidly select the promising hidden center vectors from all the training samples. Then the particle swarm optimization algorithm combined with recursive orthogonal least square algorithm was used to further prune the initial hidden centers and optimize the control parameters.

为在实际应用中加速优化速度，降低优化计算复杂度，首先提出了最小体积覆盖超球和移动平均中心覆盖超球两种算法，用于启发式的从训练样本中快速的初选出径向基概率神经网络的隐中心矢量，然后将粒子群优化算法和 ROLSA 结合进一步优选隐中心矢量，同时优化核函数控制参数，实现径向基概率神经网络的全结构优化。

Firstly, we research the Vlasov antenna with reflector mainly. A new method to calculate the radiation of the antenna is founded with Vectorial Theory of Diffraction, and the corresponding program is made. The reflective characters of Vlasov antenna are studied with Moment Methods, and the results show that the total reflected energy is less than 0.25%. The radiation patterns of the antenna are analyzed, and the formulas to estimate the wave beam parameters and to design the antenna are provided. The feasibility of radiating high-order modes by Vlasov antenna is also discussed and verified. The hermetization of the Vlasov antenna is researched and the results show that with such kinds of hermetization the antenna can work under gigawatt level. The design of the mode converter from TEM to TMoi is studied, which is useful when the TEM coaxial mode is radiated by Vlasov antenna. At last, the flared-end Vlasov antenna is also discussed.

在Vlasov天线方面：用矢量绕射理论建立了天线辐射场的计算模型并编写了计算程序，该程序计算结果在主瓣上与实验测量吻合良好，近旁瓣也基本一致；利用矩量法计算了天线的反射系数，表明该天线有较小的反射，总的能量反射小于0.25％；详细分析了天线的辐射特性，给出了天线辐射波束相关参数的估算公式和天线设计公式；进一步研究和论证了Vlasov天线辐射高阶轴对称模的可行性；对天线的密封方式和功率容量进行了讨论，结果表明在不需很大密封罩的情况下可以获得GW级的功率容量；为了用Vlasov天线辐射同轴TEM模，研究了TEM-TM_(01)模式转换器的设计，得到了一些基本规律；最后，介绍和分析了带有锥形喇叭的Vlasov天线。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。