带标识加权T—图的化简

本文首先给出带标识加权Ｔ－图的几种化简运算，然后证明在一定条件下，这几种运算能保持网的活性不变，从而为带标识加权Ｔ－图的分析和综合提供了有效途径。     

加权T图的几种化简运算

本文首先给出加权Ｔ图的几种化简运算，然后证明这几种运算于网的某些结构性质保持不变，从而为加权Ｔ图的化简及综合提供了有效途径。     

迭代投影的平顶方向图综合算法

针对现有的平顶波束综合形成算法计算量较大的问题,提出了一种迭代求解平顶波束的快速形成算法。该算法首先设置方向图参数、迭代条件,然后利用方向图与阵元加权系数的变换关系设计投影算法并通过二阶差分运算确定过渡带,最后结合蝶形计算方法快速迭代逼近理想的平顶方向图。实验结果表明,该算法相比凸优化算法运算效率较高,并且可修复阵元失效后的平顶方向图。算法运算次数随着副瓣阈值、主瓣宽度和零陷深度等参数的变化而变化。     

基于距离向多孔径接收的宽测绘带SAR成像方法的研究

该文提出了一种新的基于距离向多孔径接收宽测绘带合成孔径雷达(SAR)成像方法。首先对这种成像方法进行了严格的论证,并证明了运算中的加权矩阵为良态矩阵,然后分析了这种成像方法的计算量,讨论了这种宽测绘带SAR的信噪比,最后给出了仿真结果。     

基于捕获位置分布的导航参考图适配性分析及快速计算

导航参考图适配性分析是景像匹配导航的关键问题之一。文中提出了一种基于捕获位置分布的估计导航参考图适配性方法。该方法首先在参考图每一点挖出实测图大小的子图,然后计算子图的特征参数并应用匹配准则估计子图的匹配概率,最后利用捕获位置分布函数对子图匹配概率加权求和以得到参考图的匹配概率。为了消除特征参数计算中存在的大量冗余计算,还研究了特征参数的快速计算方法。实验结果证明该快速算法大大提高了运算效率     

基于捕获位置分布的导航参考适配性分析及快速计算

导航参考图适配性分析是景像匹配导航的关键问题之一。文中提出了一种基于捕获位置分布的估计导航参考图适配性方法。该方法首先在参考图每一点挖出实测图大小的子图,然后计算子图的特征参数并应用匹配准则估计子图的匹配概率,最后利用捕获位置分布函数对子图匹配概率加权求和以得到参考图的匹配概率。为了消除特征参数计算中存在的大量冗余计算,还研究了特征参数的快速计算方法。实验结果证明该快速算法大大提高了运算效率。     

一种基于双正交模的新型天线阵方向图综合方法

本文提出一种新型综合阵列天线方向图的模式方法。该方法基于双正交模式理论,考虑了阵元之间的耦合作用的影响,可以对任意形状的阵列天线进行方向图综合。利用双正交模式综合方法可以快速有效地获得每个阵元的特定激励,以期阵列天线的方向图满足特定的需求。模式组之间的双正交特性保证了该方法所得天线阵列方向图与期望方向图之间良好的一致性。通过对所需电场的加权,可以将整个球面上的二维曲面积分运算转化为一维线积分运算,使得方向图综合过程的计算量大为减少。若干阵列天线方向图综合实例验证了该方法的正确性和有效性。     

抽指加权的声表面波带通滤波器的计算机辅助设计

本文回顾了基于抽指加权设计的声表面波带通滤波器能够发展起来的原因,介绍了用来合成这类滤波器的计算机辅助设计程序.采用的是一种既适用于基波又适用于谐波的谱线加权换能器模型,介绍了用计算机设计的抽指加权滤波器的几个实例.     

天线相位中心位置的计算方法

本文提出了一种天线相位中心位置的计算方法,该方法基于天线远场幅度与相位方向图,能够快速计算出天线相位中心位置。首先建立天线相位中心位置与远场相位方向图之间的模型,然后求远场相位SSD对位置偏移的偏导,得到相位SSD的最小值以及此时的位置偏移。在计算相位中心的过程中可以根据要求选取不同的幅度加权方法,在计算结束后,通过补偿后的相位方向图来比较几种加权方法的计算效果。     

基于傅里叶系数权函数的宽带波束形成算法

提出了一种基于傅里叶级数系数函数权的宽带恒定束宽波束形成方法。该方法首先确定各个子带中心频率处的波束响应图,继而利用傅里叶系数求取公式分别求得各个子带中心频率处对应的权函数。并通过仿真验证了该方法可实现在信号带宽内基阵波束图主瓣宽度保持恒定,与基于Bessel函数的方法相比,具有更高的运算效率。     

Multiplication-free adaptive digital filters

The authors update delta modulation digital filter weights using the LMS (least-mean-squares) and the SIGN algorithms to realize an adaptive digital filter without multiplication operations. It is shown that using the SIGN algorithm results in an adaptive filter that can be implemented using the simple up/down counting operations. Learning curves demonstrating convergence properties of the algorithms for a system identification problem are presented     

云计算中基于QoS的调配优化算法

研究和设计云计算环境下一种优化的基于QoS约束的调配算法,并验证其正确性。在QoS需求下采用具有服务等级协议(SLA)参数的约束条件,对任务划分优先级,形成优先级队列。SLA服务参数采用二进制权值的方法进行标记,避免了作业分级重叠的情况。在对该任务分配计算资源时,采用资源等级队列的方法,分配合理的工作节点。通过对几种算法的比较实验,验证优化算法运转的鲁棒性和正确性。     

Gray code weighting system (Corresp.)

Contrary to what has been believed, it is found that weights can be associated with different bit positions of the standard binary reflected Gray code. Therefore, two algorithms are devised for direct Gray-to-decimal and decimal-to-Gray conversions. These algorithms are much simpler than old algorithms which involve conversions to and from binary code and exclusive-OR operations.     

Envelope-constrained time-domain deconvolution for transversal-filter equalisers

A deconvolution algorithm is presented for calculating the N tap weights of a transversal-filter equaliser. The procedure attempts to control the size of individual, time-domain response errors rather than simply minimise total mean-square error of the response. A least-square error solution for the tap weights is iteratively modified, using only elementary algebraic matrix operations, in an effort to satisfy tolerance constraints on the envelope of the equalised impulse response. The algorithm is suitable for digital computation.     

神经网络余数制系统与余数制神经网络模型

余数制和神经网络各有其独特优点，将其有机结合这些优点得以充分发挥。将神经网络结构和方法引人余数制信号处理系统，构造出完成余数约化运算和余／十转换运算以及余数加法运算的新结构，开辟了高速实时信号处理的新途径．将余数制引入神经网络，即神经网络中的数据、权值均按余数制表示和运算，构造出一种新的感知机模型—余数制神经网络，由于余数制运算具有一种独特的非线性特点，使这种模型比常规神经网络具有更强的功能。     

Adaptive processing using real weights based on a direct data domain least squares approach

In traditional, adaptive signal processing algorithms one change both the amplitude and phase of the weight vectors associated with an array at each of the antenna elements. The use of complex weights offers greater control over the array response at the expense of system complexity. However, it is easier if one requires only amplitude variation with a fixed phase for all the weight vectors associated with all the antenna elements. Because one uses only real arithmetic operations to find the amplitude of the weights connected to the antenna, the computational complexity is reduced considerably. Hence, this paper addresses the use of real weights in an adaptive system. In this paper we describe a new direct data domain least squares (D/sup 3/LS) method using real weights, which utilizes only a single snapshot of the data for adaptive processing. This technique may be useful for real time implementation of the D/sup 3/LS method on a chip.     

Efficient Hamming Weight Comparators for Binary Vectors Based on Accumulative and Up/Down Parallel Counters

New counting-based methods for comparing the Hamming weight of a binary vector with a constant, as well as comparing the Hamming weights of two input vectors, are proposed. It is shown that the proposed comparators are faster and simpler, both in asymptotic sense and for moderate vector lengths, compared with the best available fully digital designs. These speed and cost advantages result from a more efficient population counting, as well as the merger of counting and comparison operations, via accumulative and up/down parallel counters.      

基于层次-效用法的空中目标威胁度判断模型

在现代防空作战中,要对来袭目标进行指标因素区分.利用层次分析法(AHP)来确定各指标因素的权重,建立指标因素的效用函数矩阵,计算出目标的威胁度,并进行威胁度大小排序,是防空一方指挥员合理、准确地运用火力的重要依据.     

Fast Block Center Weighted Hadamard Transform

Motivated by the Hadamard transforms and center weighted Hadamard transforms, a new class of block center weighted Hadamard transforms (BCWHT) are proposed, which weights the region of midspatial frequencies of the signal more than the Hadamard transform. Based on the Kronecker product, direct sum operations, the identity matrix and recursive relations, the proposed one and 2-D fast BCWHTs algorithms through sparse matrix factorization are simply obtained.     

On superresolution effects in maximum likelihood adaptive antenna arrays

The superresolution performance of maximum likelihood (Frost) adaptive antennas is analyzed. Assunming that the adaptive weights have had enough time to converge to the optimal (Wiener) solution, the beampattern and spatial resolution of the array are computed. Simple expressions are derived which allow close-approximation computations of converged adaptive beampatterns using only scalar operations. The analysis applies to narrow-band line-array adaptive beamformers. Computer simulations are presented to verify the excellent match between theoretical and measured beampatterns for small angle deviations from the look direction.