子阵

Final, improve of beam-pointing drift with digital delayer at elements or sub-arrays is given.

文章也给出了阵列单元或子阵设置数字延迟器后，扫描波束指向漂移改善的分析结果。

On the basis of array model of the Multiple-Input Multiple-Output radar, a universal array model of the Synthetic Impulse and Aperture Radar is constructed and a realization sheme for microwave SIAR with a thinned subarray set for the transmitted array and a dense subarray set for the received array is proposed.

结合MIMO雷达多发多收的特点，建立了微波综合脉冲孔径雷达的阵列模型，并提出该阵列的一种实现方案：发射阵采用稀布子阵集，接收阵采用密布子阵的形式。

However the available direction estimation region is only within the 3dB beam width of subarrays,in order to estimate at any interested direction one can combine this method with beam scanning.

但其有效的方向估计范围只在子阵的3dB波束宽度内，然而与波束扫描相结合可实现任意空间范围内的方向估计。

The method transfers the observed data from space domain to 2-D space-time domain by exploiting the cross-correlation of the array outputs,and a large amount of virtual elements are generated through space-time processing.Therefore the constraint over the array configuration and the element identity can be significantly weakened,which means the matching subarray is no longer needed and the advantage of the traditional DOA matrix method,such as automatical parameter alignment and no need of 2-D search,is still available.

该方法在保持原DOA矩阵方法无需二维谱峰搜索和参数配对等优点的基础上，利用阵元输出之间的互相关关系将空域的阵列观测数据变换到时空域，通过空时二维处理在时空域中衍生出大量虚拟阵元，从而大大减弱了传统方法中对阵列结构、排布方式和阵元一致性的约束，不需要匹配子阵，无冗余阵元与孔径损失，并适用于阵元排列不规则的阵列。

The integral steering vector of coherently distributed source is deduced to be a Schur-Hadamard product comprising the steering vector of the point source and a real vector. And then a second statistics is proposed for the data collected at subarray X, the rotational invariance matrices can be estimated based on propagator method.

该算法通过将积分形式的相干分布式信源方向向量化简为点信源方向向量与实向量的Schur-Hadamard积，对子阵X接收的数据构造二阶统计量；利用传播因子最小二乘估计子阵X与Z，X与W之间的旋转不变矩阵。

To the problem that the isotropy and the technological efficiency of the parallel kinematic machine based on Stewart platform are not satisfactory, a novel architecture of 6-DOF 3-dimensional platform parallel kinematic machine (6-DOF 3-D PPKM) based on the 2-2-2-SPS 3-D PPR is presented. The technological efficiency of design of the parallel kinematic machine is analyzed. Its workspace and the effect of design parameters to the workspace volume are studied. By using the submatrices of Jacobian matrix and force Jacobian matrix, the kinematics/mechanics transmission isotropic indices, kinematics transmission indices, load-bearing capacity indices at any configuration of the parallel kinematic machine are proposed, respectively.

分析其结构和装配工艺性，研究其定位姿工作空间及机床结构参数对工作空间大小的影响，基于Jacobian矩阵和力Jacobian矩阵中同量纲元素构成的子阵，提出该并联机床在任意位姿的运动／力学传递各向同性评价指标、运动学传递能力评价指标和承载能力评价指标；基于柔度矩阵中同量纲元素构成的子阵，提出该并联机床在任意位姿的力-位置柔度评价指标、力-姿态柔度评价指标、力矩-姿态柔度评价指标和力矩-位置柔度评价指标；研究各性能指标在定位姿工作空间内的分布情况。

The processor (50) generates partial matrix H1 to satisfy the conditions that, when any two rows contained in partial matrix H1 are selected, the two rows have periods that are relatively prime, or when the periods are identical, the two rows have different phases.

处理器(50)产生子阵H1以满足以下条件：当选择子阵H1中所包含的任何两行时，这两行具有互质的周期，或者当周期相同时，这两行具有不同的相位。

And the sufficient and necessary conditions are obtained and the uniqueness of T is discussed and an algorithm for solving the inverse problem is provided. The other kind of structure inverse eigenvalue problem is for unitary Hessenberg matrices with positive subdiagonal elements. That is, a unitary Hessenberg matrices with positive sub-diagonal elements can be constructed when its eigenvalues and the eigenvalues of H_(11) and H_(22) are known. Here H_(11) and H_(22) are rank-one modifications of k × k leading principal submatrix of H and of its × remain submatrix respectively. In the end, the uniqueness of H and an algorithm is obtained.

文中首先讨论了这三组特征值之间的交错关系，接着确定了该逆问题有解的充要条件，并论证了其解的唯一性问题，最后给出了相应的数值算法；本文第二个问题解决的是一类不可约的酉Hessenberg阵的逆特征值问题：即一个不可约的酉Hessenberg阵可以由它的特征值、它的前k阶秩一修正的顺序主子阵的特征值以及它的后n—k阶余子阵的秩一修正阵的特征值来确定，文中最后讨论了唯一性和相应的算法。

Firstly, an inverse eigenvalue problem for Jacobi matrices is presented: we could construct the Jacobi matrix T if we know the spectral data: the eigenvalues of T and the eigenvalues of T_1 and of T_2, where T_1 is different to the k × k leading principal submatrix of T only at the position, while T_2 is different to the × remain submatrix only at the (1, 1) position.

首先给出的是一类Jacobi阵的逆特征值问题，即给定三组实数：一组是Jacobi阵的n个特征值，一组是只修改了最后一个对角元的它的前k阶顺序主子阵的特征值，最后一组是修改了第一个对角元的后n—k阶余子阵的特征值，用这些给定的特征值来确定相应的Jacobi矩阵。

It results that although the improvement factor is higher with the number of sub-arrays, the distribution rule of residue clutter plus noise power or the output signal to clutter plus noise ratio doesn't show monotonical relationship with the number of sub-arrays.

研究结果表明：虽然子阵数越多改善因子越高，但在辅助样本数一定的前提下剩余杂噪功率和输出信杂噪比的分布规律并不随子阵数增多而单调趋好。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐