Design efficiency for minimum projection uniformity designs with two levels

The objective of this paper is to study the issue of design efficiency for minimum projection uniformity designs. The results show that for orthogonal arrays with strength two, the minimum projection uniformity criterion is a good surrogate for the design efficiency criterion proposed by Cheng, Deng and Tang (2002).     

覆盖网络组播压力与伸长度的性能评价模型

提出了覆盖网络组播的链路压力均衡模型和组播树特征伸长度模型，用以评价覆盖网络组播协议的性能。链路压力均衡模型采用均匀性度量的偏差准则来衡量组播中的压力分布。组播树特征伸长度模型通过寻找路径伸长度密集分布区域来评价组播路径的优化程度。仿真结果表明，这两种模型能够很好地反映覆盖网络组播协议在压力和伸长度方面的性能。     

Hybrid alternate projection algorithm and its application for practical conformal array pattern synthesis

Based on the fabricated 12-element cavity-backed microstrip sector cylinder array,a novel hybrid alternate projection algorithm(HAPA),which combines analytical method with numerical techniques effectively,is proposed for synthesizing the pattern of practical conformal array.The algorithm applies the variable direction aperture projection method with mutual coupling correction techniques to provide the good initial excitations of elements to the enhanced alternate projection algorithm(EAPA).In order to do further optimization,which improves the convergent speed of the algorithm significantly.Finally,the HAPA has been applied to the fabricated sector cylinder array with mutual coupling considered.The results of synthesized patterns,such as low sidelobe with null points formed pattern,beam scanning with low sidelobe pattern and the shaped beam pattern are presented.It demonstrates the validity of HAPA in practical conformal array synthesis.     

相控阵的子阵级数字波束扫描方法研究

在子阵级相控阵中,对于多波束形成等很多应用,需要在子阵级进行数字波束扫描。此时抑制扫描后的方向图旁瓣是一个重要问题。基于具有圆形投影区域的期望子阵方向图,构造了子阵级加权网络,通过对子阵输出进行后处理得到了新的子阵方向图,从而抑制了子阵级波束扫描的方向图旁瓣。该方法与基于矩形投影区域的期望子阵方向图方法相比,提高了子阵级波束扫描的旁瓣抑制性能。仿真结果验证了理论分析的有效性。     

Low side lobe pattern synthesis using projection method with genetic algorithm for truncated cone conformal phased arrays

A hybrid method for synthesizing antenna＇s three dimensional （3D） pattern is proposed to obtain the low sidelobe feature of truncated cone conformal phased arrays. In this method, the elements of truncated cone conformal phased arrays are projected to the tangent plane in one generatrix of the truncated cone. Then two dimensional （2D） Chebyshev amplitude distribution optimization is respectively used in two mutual vertical directions of the tangent plane. According to the location of the elements, the excitation current amplitude distribution of each element on the conformal structure is derived reversely, then the excitation current amplitude is further optimized by using the genetic algorithm （GA）. A truncated cone problem with 8x8 elements on it, and a 3D pattern desired side lobe level （SLL） up to 35 dB, is studied. By using the hybrid method, the optimal goal is accomplished with acceptable CPU time, which indicates that this hybrid method for the low sidelobe synthesis is feasible.     

铜闪速熔炼过程操作模式分级匹配技术与演化策略

针对铜闪速熔炼过程关键工艺参数无法在线检测、过程建模及优化控制困难的问题, 阐述了基于数据的铜闪速熔炼过程操作模式优化方法. 基于综合工况评判指标及操作模式智能分类方法构建优良操作模式库, 在此基础上, 提出操作模式分级匹配技术; 借助投影寻踪回归思想, 建立操作模式与综合工况评判指标之间的非线性关系模型, 采用基于实数编码的加速遗传算法进行最优操作模式的获取, 实现熔炼过程的优化控制. 某冶炼厂生产数据验证了所提方法的可行性.     

聚类分析在彩色图像量化中的应用

提出了一种基于模式识别技术的彩色图像量化的新算法—基于最小距离最大的快速统计聚类算法(FSCAMMD)。本算法克服了SCA算法对聚类中心初始值选取的不足,给出了最大频度与类内最小距离最大相结合的方法—初始值优选法。实验结果表明,本算法可较大幅度地减少图像量化后的总方差以及颜色失真度,量化效果优于SCA和其它一些聚类量化算法。     

基于自适应哈希链的分布式频繁模式挖掘算法

针对分布式系统,提出了自适应哈希链结构的频繁模式挖掘算法。该算法首先在每个站点产生局部频繁1-项集,再产生全局频繁1-项集,根据全局频繁1-项集产生各站点的投影数据库,在各个站点分别扫描投影数据库中的交易,并根据站点可用内存情况形成相应大小的哈希链结构。通过挖掘各站点的哈希链结构得到全局频繁项集。给出了基本步骤和挖掘算法。研究表明该算法不但效率高,而且适应性强。     

基于不确定性问题研究方法评价系统参数的重要性

探讨了利用对信息不确定性问题的研究来评价系统参数的重要性的方法 .首先讨论了根据信息熵的概念研究信息的不确定性 ,通过对信息的不确定性研究 ,提出模式识别系统中选取有效特征的概率统计方法 ;其次基于粗集理论思想 ,利用对于不确定性问题的近似分类概念研究了评价系统参数重要性的方法 .最后对两种方法作了一简单比较 ,并探讨粗集方法与概率统计方法在模式识别系统中选取重要特征准则下的统一性.     

局域网中分布式仿真系统的通讯模型

分布式多机仿真中，每当增加新的仿真子模块，就需要重新规定与其进行通讯的模块的消息接口以及新增模块的消息解析模块，无论是编程还是调试都较为繁琐。为解决上述问题，提出一种松散架构的分布式仿真通讯模型。这一通讯模型可以实现较为便捷的模块加入和删除工作。利用这一模型实现的网络通讯模块在虚拟航海仿真系统以及多屏投影系统的通讯模块中得到了应用。给出了应用结果并对几种不同通讯部署方式的应用性能进行了讨论。     

AHP中判断矩阵一致性修正的模式识别法

基于模式识别原理，给出了判断矩阵一致性修正的一种方法。在该方法中，首先把由专家或决策者给出的判断矩阵Ａ转化为ｎ个具有完全一致性的正互反阵。再将这ｎ个正互反阵和Ａ分别转化为反对称阵Ｂ（ｉ），ｉ＝１，…，ｎ和Ｂ。在Ｂ（ｉ），ｉ＝１，…，ｎ生成的线性空间中寻找与Ｂ最贴近的正互反阵Ｂ～＊，将Ｂ～＊对应的满足完全一致性的正互反阵Ａ～＊作为Ａ的修正矩阵，同时得到了Ａ～＊对应于最大特征值ｎ的正特征向量的计算公式。     

基于典型散射差异指数的PolSAR图像Lee滤波

为提高滤波后极化合成孔径雷达图像的边缘清晰度和保持目标的极化特性,提出了基于典型散射差异指数(typical scattering difference index, TSDI)的PolSAR图像Lee滤波算法。算法根据滤波像素和邻域像素之间的TSDI,采用自适应阈值法筛选出滤波像素的同质像素,然后用同质像素进行Lee滤波。针对筛选阈值,首先利用Parzen窗估计同质区域TSDI概率分布,然后根据估计结果计算阈值。用美国AIRSAR系统和UAVSAR系统采集的极化数据进行实验。实验结果表明该算法相对于精致Lee滤波算法相干斑抑制更加彻底,同时图像边缘清晰度和目标极化特性保持更完好。     

基于“垂面”距离的TOPSIS法——正交投影法

针对TOPSIS法的不足之处,提出了一种改进方法:基于"垂面"距离的TOPSIS法——正交投影法.回顾了TOPSIS法.定义"垂面"距离,讨论垂面距离的计算、性质、以及与目标贴近度的关系.给出经过简化的正交投影法的计算步骤.举一个具体的例子,应用正交投影法进行评估.总结正交投影法的优点.     

Optimal binary codes from one-lee weight codes and two-lee weight projective codes over ℤ4

This paper investigates the structures and properties of one-Lee weight codes and two-Lee weight projective codes over Z4.The authors first give the Pless identities on the Lee weight of linear codes over Z4.Then the authors study the necessary conditions for linear codes to have one-Lee weight and two-Lee projective weight respectively,the construction methods of one-Lee weight and two-Lee weight projective codes over Z4 are also given.Finally,the authors recall the weight-preserving Gray map from（Z4n,Lee weight）to（F2（2n）,Hamming weight）,and produce a family of binary optimal oneweight linear codes and a family of optimal binary two-weight projective linear codes,which reach the Plotkin bound and the Griesmer bound.     

On the Properties of Cheng Projection

This paper mainly investigates some properties of Cheng projection, which was proposed recently by Prof. Cheng to reduce the dimension of vector. As a linear transformation from the original vector space to the target vector space, the matrix representation of Cheng projection is given. Then,the structure matrix of Cheng projection, called the Cheng projection matrix, is obtained. Algebraic properties of Cheng projection are derived via its projection matrix. Furthermore, the product and norm of Cheng projection matrices are concerned.     

一种基于高阶统计量的图像识别算法研究

提出了一种基于图像高阶统计量的识别算法。利用Radon变换将图像数据变换到一维空间,通过计算投影数据的双谱构造出具有比例和平移不变性的特征。利用Rapid变换获得特征的旋转不变特性;接着,利用阈值分析的方法进行特征选择,获得了较原始特征更好的识别效果。针对特征向量过长的问题,利用主元分析进行长度压缩。与不同方法的实验比较表明,算法能够有效地用于图像识别。     

三维成像系统的性能仿真分析

基于条纹投影方法和主动三角化技术，详细分析三维光学数字成像系统的性能，并对其进行仿真分析。首先简单描述系统的结构。然后定量分析各个参数对系统性能的影响，具体包括：成像系统出瞳和测量参考面之间的距离；成像系统出瞳和投影系统入瞳之间的距离；投影条纹的空间周期。最后用模拟数据对系统进行验证，结果说明所得到的三维测量数据更加精确。     

THEORETICAL AND NUMERICAL COMPARISON ON DOUBLE-PROJECTION METHODS FOR VARIATIONAL INEQUALITIES

Recently, double projection methods for solving variational inequalities have received much attention clue to their fewer projection times at each iteration. In this paper, we unify these double projection methods within two unified frameworks, which contain the existing double projection methods as special cases. On the basis of this unification, theoretical and numerical comparison between these double projection methods is presented.     

投影神经网络及其应用

本文提出了一种投影神经网络以实现模式矢量向某一空间的投影,文中详细讨论了网络的结构,并提出了一种调整联接权的格形学习算法。本文将投影神经网络应用于飞机目标冲激响应波形的识别问题,得到了良好的效果,研究结果表明这种投影神经网络具有投影精度高、实时性好的优点。     

Macwilliams Identities of Linear Codes over the Ring F_2+ uF_2+ vF_2

The Lee weight enumerators and the complete weight enumerators for the linear codes over ring R = F2 + u F2 + v F2 are defined and Gray map from Rnto F3n2 is constructed. By proving the fact that the Gray images of the self-dual codes over R are the self-dual codes over F2, and based on the Mac Williams identities for the Hamming weight enumerators of linear codes over F2, the Mac Williams identities for Lee weight enumerators of linear codes over R are given. Further, by introducing a special variable t, the Mac Williams identities for the complete weight enumerators of linear codes over R are obtained. Finally, an example which illustrates the correctness and function of the two Mac Williams identities is provided.