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1.
A purely algebraic method which uses the matrix Routh algorithm and its reverse process of the algorithm is presented to decompose a matrix transfer function into a pair of right co-prime polynomial matrices or left co-primo polynomial matrices. The poles and transmission zeros of the matrix transfer function are determined from a pair of relatively prime polynomial matrices. Also, the common divisor of two matrix polynomials can be obtained by using the matrix Routh algorithm and the matrix Routh array.  相似文献   

2.
A stable proper right (left)nth-order inverse of a given linear time-invariant system of orderncan always be constructed, via a simple algorithm, if a proper right (left) inverse exists and the zeros of the given system are stable. Furthermore, it is shown that all of the poles of this inverse can be arbitrarily assigned except those which equal the zeros of the given system.  相似文献   

3.
经典字符串匹配算法的本质都是从左向右或者从右向左顺序进行字符匹配的,在主串中存在大量子串与模式串前缀或者后缀相同时效率较低,并且模式串最大右移长度为模式串长度。改进算法采用二分匹配字符串的方法,有效地避免了由主串中大量子串与模式串前缀相同或者后缀相同引起的无意义比较次数。模式串的移动距离根据改进的坏字符规则进行计算,增大了模式串的移动距离。实验结果表明,改进的字符串匹配算法可以有效地减少字符串的匹配次数和移动次数,达到了提高算法效率的目的。  相似文献   

4.
We investigate the quantum image matching algorithm proposed by Jiang et al. (Quantum Inf Process 15(9):3543–3572, 2016). Although the complexity of this algorithm is much better than the classical exhaustive algorithm, there may be an error in it: After matching the area between two images, only the pixel at the upper left corner of the matched area played part in following steps. That is to say, the paper only matched one pixel, instead of an area. If more than one pixels in the big image are the same as the one at the upper left corner of the small image, the algorithm will randomly measure one of them, which causes the error. In this paper, an improved version is presented which takes full advantage of the whole matched area to locate a small image in a big image. The theoretical analysis indicates that the network complexity is higher than the previous algorithm, but it is still far lower than the classical algorithm. Hence, this algorithm is still efficient.  相似文献   

5.
Stereo by intra- and inter-scanline search using dynamic programming   总被引:14,自引:0,他引:14  
This paper presents a stereo matching algorithm using the dynamic programming technique. The stereo matching problem, that is, obtaining a correspondence between right and left images, can be cast as a search problem. When a pair of stereo images is rectified, pairs of corresponding points can be searched for within the same scanlines. We call this search intra-scanline search. This intra-scanline search can be treated as the problem of finding a matching path on a two-dimensional (2D) search plane whose axes are the right and left scanlines. Vertically connected edges in the images provide consistency constraints across the 2D search planes. Inter-scanline search in a three-dimensional (3D) search space, which is a stack of the 2D search planes, is needed to utilize this constraint. Our stereo matching algorithm uses edge-delimited intervals as elements to be matched, and employs the above mentioned two searches: one is inter-scanline search for possible correspondences of connected edges in right and left images and the other is intra-scanline search for correspondences of edge-delimited intervals on each scanline pair. Dynamic programming is used for both searches which proceed simultaneously: the former supplies the consistency constraint to the latter while the latter supplies the matching score to the former. An interval-based similarity metric is used to compute the score. The algorithm has been tested with different types of images including urban aerial images, synthesized images, and block scenes, and its computational requirement has been discussed.  相似文献   

6.
小波变换在三维医学图象分割中的应用   总被引:4,自引:0,他引:4  
本文将多尺度小波变换应用到三维医学图象分割中的阈值选取中.由于小波变换在较大尺度,由噪音引起的细小突变较少,可描述信号的整体行为,取较大尺度的由负到正的零交叉点来确定图象的阈值,再逐步到相邻的小尺度由粗到精地确定精确的阈值.用以上算法对三维医学图象进行二值化后,根据待提取组织或区域的特征,再选取合适的数学形态学操作,最后对区域进行种子填充.从实验结果可以看出分割效果较好,能够满足三维重建的要求.  相似文献   

7.
Summary Left context precendence grammars which are defined in this paper are a proper subclass of the precedence grammars and contain properly the simple precedence grammars. Left context precedence grammars need not be uniquely invertible. The parsing algorithm developed for left context precedence languages works with linear time and has the viable prefix property which is a stronger property than the correct prefix property.  相似文献   

8.
在牙齿三维矫正中需要对牙齿进行排列,常用方法是通过人机交互完成,效率不高。提出了一种基于粒子群的自动化排牙方法,将每颗牙齿上的特征点到标准牙弓曲线的距离和作为目标函数,利用粒子群算法对解空间进行搜索,在搜索过程中加入约束条件,得到牙齿移动的最终位置。利用该算法对牙齿进行排列,可以省去人机交互中的平移等操作。实验结果表明该算法能够有效地用于牙齿三维矫正中,提高了排牙效率。  相似文献   

9.
基于距离正则水平集模型(DRLSE)的左心室MR图像分割算法对梯度信息有很强的依赖性,在图像弱边缘区域容易陷入局部最优,且对初始轮廓的选取敏感。为降低算法对初始轮廓的敏感程度,提高其在左心室图像弱边缘的分割能力,提出一种适用于弱边缘信息的左心室分割算法。在DRLSE的基础上,该分割算法提出运用拟合方法计算基于变异系数分割模型(PSM)的新局部项,算法依靠梯度与图像局部信息驱动曲线演化,降低了DRLSE对初始轮廓的敏感度;引入形状约束力,克服DRLSE算法在左心室外膜弱边界处出现边界泄露的情况。为验证所提算法分割的准确性,基于多伦多市患病儿童医院影像科提供的数据库,利用DRLSE、保持凸性水平集模型(CPLSE)模型、U-Net网络以及提出的内膜算法对心内膜进行分割;利用DRLSE、引入外膜形状约束力的DRLSE模型(DRLSE-shape)、U-Net网络以及提出的外膜算法对心外膜进行分割。实验结果表明,针对左心室内、外膜,所提算法优于上述算法,能降低DRLSE对初始轮廓的敏感程度,提升对左心室弱边界MR图像分割的精确度。  相似文献   

10.
基于相关系数的隐私保护关联规则挖掘   总被引:1,自引:0,他引:1       下载免费PDF全文
传统的隐私保护关联规则挖掘算法由于没有考虑规则左右件相关系数的影响,对非敏感规则的支持度影响很大。为了减小这种影响,提出通过调整规则左右件相关系数隐藏敏感规则的算法。该算法通过调整相关系数,使敏感规则的价值无法被发现,从而达到隐藏敏感规则的目的。实验结果表明,该算法的规则丢失率和相异度均有所下降。  相似文献   

11.
格线删除是计算机自动笔迹鉴定系统预处理过程中的关键步骤。在分析已有的手写汉字文本格线删除算法利弊的基础上。采用Pavlidis提出的块邻接图表示法来进行格线删除。并提出了格线删除后的笔画重构算法。该算法首先采用链表结构将笔迹图像保存为块邻接图;然后根据该邻接图搜索出满足条件的连通子图,这些连通子图就是需要删除的格线;最后再对因格线删除而断开的笔画进行重构。由于块邻接图只需进行一次水平或垂直扫描就能获得,因此格线的搜索和删除非常迅速;同时该算法还考虑了格线删除后的笔画重构,这样既删除了笔迹图像中的干扰信息,又不改变笔迹图像的特征。实验结果显示,该方法具有很强的抗干扰能力,对格线的删除非常有效。  相似文献   

12.
交替运动转向行为,即动物在迷宫中连续转向时,其运动转向与前一次转向是相反的。传统做法是利用人工观察和手工记录,观察动物的运动转向行为。基于视频的运动行为分析为动物行为研究提供了一种便捷、准确的研究工具,然而这些方法主要针对大鼠、小鼠和昆虫类等动物。潮虫(woodlice)是一种研究动物交替转向行为的常用实验动物,其个体远小于小鼠,又比果蝇大许多。由此提出了一种适用于潮虫的视频自动分析算法,该算法利用线性迭代的跟踪算法获得运动信息,同时可以获得潮虫运动转向与转向时间。实验结果表明:运动转向和运动转向时间结果比较准确。此方法为交替转向行为研究提供了一种准确客观的实验工具。  相似文献   

13.
14.
针对区间多目标优化问题,利用云模型对NSGA-II算法进行改进,提出一种非支配排序云模型算法(NSCMA)。首先,从初始云团中随机选取一个云滴作为父代,通过正态云算子生成子代云滴,用来替代传统NSGA-II遗传操作中的交叉和变异;其次,用约束条件对生成的云滴进行筛选处理,避免不可行解进入下一步算法;最后,运用区间占优关系对满足约束条件的解进行占优排序,对无法比较的同序值解计算拥挤距离。仿真结果验证了所设计算法的有效性。  相似文献   

15.
程一飞 《微机发展》2007,17(11):157-159
很多基于椭圆曲线的密码协议都需要计算多标量乘法kP lQ。目前常见的多标量乘算法的效率主要取决于标量的(联合)海明权值。JSF表示的平均联合海明权密度为1/2,是所有带符号二进制表示中最优的,但JSF编码只能从右到左实现。提出一个新的从左到右的基于MOF的编码方法,该方法的平均联合海明权密度与基于JSF表示的相同,并提出一个新的多标量乘算法,该算法对标量从左到右进行编码,并将编码合并到多标量乘的主计算中,从而节省了存储标量的新编码的内存空间,提高了实现效率。  相似文献   

16.
As the standard iris biometric algorithm “sees” them, the left and right irises of the same person are as different as irises of unrelated people. Similarly, in terms of iris biometric matching, the eyes of identical twins are as different as irises of unrelated people. The left and right eyes of an individual or the eyes of identical twins are examples of genetically identical irises. In experiments with human observers viewing pairs of iris images acquired using an iris biometric system, we have found that there is recognizable similarity in the left and right irises of an individual and in the irises of identical twins. This result suggests that iris texture analysis different from that performed in the standard iris biometric algorithm may be able to answer questions that iris biometrics cannot answer.  相似文献   

17.
《自动化博览》2011,(Z2):43-48
The nesting problem has been for many years a subject of interest to shipbuilders as continuously rising price of raw material.An optimized steel plate cutting plan saves shipyard both time and material,improves production efficiency,and in return enhances the company’s competition capability.In this paper,the author will propose a polygon nesting method using bottom left strategy with genetic algorithm.The algorithm allows parts to be nested within several steel plates which have fixed sizes by searching a suitable accommodate node among the intersection points of the no-fit polygons of previously placed parts relative to the new part following a bottom left policy.We verify this algorithm using a rectangular nesting problem from published literatures.And then give more computational experiments on polygon nesting problems.  相似文献   

18.
钢结构节点详图的自动标注算法   总被引:2,自引:0,他引:2       下载免费PDF全文
钢结构设计是计算机辅助设计中的一个重要分支,对钢结构工程图纸进行自动标注不仅可以极大地提高设计效率,而且能提高钢结构设计的准确性和自动化程度,为了产生有序的图纸注,结合钢结构软件的开发,提出了针对钢结构节点详图的实用性自动标注策略,并详细介绍了其中的布局策略等关键算法,从而为最终找到全自动的图纸生成方法进行有益的探索,该算法及自动标注策略所涉及的工作已经在PDSOFT Steelworks钢结构软件的开发工作中全部实现。  相似文献   

19.
A new method for the computation of two-sided Gröbner bases of ideals and bimodules shifting the problem to the enveloping algebra is proposed. This alternative method appears to be more efficient than the one in [Kandri-Rody, A., Weispfenning, V., 1990. Non-commutative Gröbner bases in algebras of solvable type. J. Symbolic Comput. 9, 1–26] since it calls the left Buchberger algorithm once. We introduce the notion, arising from the ideas that this method involves, of two-sided syzygy, which is revealed to be useful in the computation of, e.g., the intersection of bimodules. Further applications are left for a later work.  相似文献   

20.
一种基于检索结果集的图像检索相关反馈算法   总被引:1,自引:0,他引:1       下载免费PDF全文
基于内容的图像检索相关反馈方法大都把着眼点放在调整用户反馈和修改系统的查询策略上,忽略研究每轮检索结果包含的丰富信息。本文基于移动查询点算法,提出截取部分检索结果作为检索结果集,在结果集中使用SVM方法并以系统交互过程的记忆为辅助得到最终结果的方法。由对比实验表明,本文的方法比传统反馈方法具有更高的查准率和查全率。  相似文献   

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