基于多通道Gabor滤波和2DPCA的虹膜识别算法

为提高虹膜识别系统的识别率和识别时效性,设计了基于多通道Gabor滤波和二维主分量分析(2DPCA)的虹膜识别算法。利用多通道Gabor滤波器对采集的虹膜进行特征提取。由于得到的特征向量矩阵的维数通常较大,会影响特征匹配和虹膜识别的运算速度,因而需要对特征矩阵进行降维处理。2DPCA算法能有效地克服传统虹膜识别系统中的"维数危机"问题,在保留虹膜特征主分量的基础上,降低虹膜匹配运算量,提高虹膜系统的识别效率。虹膜识别采用差异度匹配法,通过阈值比较得到识别结果,对容量不等的各类虹膜图库均具有良好的适应性。实验中对容量为50的虹膜图库进行了算法测试,系统的最低识别率达到了88%,识别时间仅为传统非降维识别方法的一半。理论分析和实验结果表明,该算法对虹膜纹理的特征提取精度高,识别率高,识别速度快。     

基于Gabor核函数窗设置的图像识别

提出一种依据Gabor核函数窗的设置对红外图像进行识别,首先给出Gabor核函数窗的定义,分析核函数窗对红外图像识别卷积过程,给出了核函数窗的时窗和频窗,最后在对红外图像滤波识别时给出了最优核函数窗的计算方法。计算机仿真实验表明,只有在优化核函数窗设置设置情况下,才能取得了较好的识别结果。     

纹理的不变性特征和识别性能的视觉心理学研究

设计了三个视觉心理学实验,对人眼识别纹理过程中是否也提取了不变性的特征、以及目前的计算机识别算法的性能是否超过人眼视觉系统的纹理识别性能问题进行了实验比较,结果发现:(1)几种计算机识别算法的不变性性能与人类视觉系统的纹理不变性性能基本上是一致的;(2)人类视觉系统对纹理识别具有旋转不变性。纵观人类视觉系统,单独的数字"6"和"9"认知区别很明显,一旦它们各自随机排列,形成纹理图像后,人类视觉系统会判断为同一纹理;(3)纹理特征由物体表面所展现,它取决于视觉分辨率。观测条件在某些设定情形下,人眼视觉系统纹理特征的空间尺度,其缩放尺度不变的范围大约为2.3倍;(4)一些计算机纹理分类算法的性能在限定条件下(如多尺度纹理斑块特征方法和Gabor滤波器方法),能够达到甚至超过人类视觉系统对纹理的识别能力。     

基于激光测距法的智能虹膜识别系统设计

针对传统虹膜识别系统计算复杂、实时性差等问题,设计了一种激光测距法的智能虹膜识别系统。在Gabor滤波图像的基础上,利用分块图像的幅值均值和相位信息来提取虹膜特征量,并结合k-近邻算法来完成虹膜识别功能,减小识别时间并提高识别准确度;同时,针对红外相机在日夜转换时因可见光与红外光波长不同导致的虚焦、画面模糊现象,采用激光测距法自动对焦,实现低成本、快速、精确的人眼图像预处理。本设计将识别结果通过WiFi发送至云端服务器,减少了布线。经测试,该系统运行稳定、识别速度快,已应用于某安防系统。     

含复指数函数对偶积分方程的数值求解

在断裂力学和热弹性动力学中，常常会出现含复指数函数对偶积分方程的求解，此类方程不能直接用Copson-Sih方法求解。文中基于Copson—Sih方法，证明了含余弦函数的对偶积分方程可化为第二类Fred—holm积分方程进行数值求解。利用欧拉公式，可将含复指数函数的对偶积分方程为含正余弦函数的对偶积分方程，进一步可转化为第二类Fredholm积分方程进行数值求解。最后给出了含余弦函数对偶积分方程的数值算例。     

基于Gabor滤波和纹理分析的票据手写体字符鉴别

特征提取是模式识别技术中的重要环节,在图像特征提取方面有很多的算法。利用手写体字符具有的纹理特征,在经过必要的预处理操作之后,通过构造Gabor滤波器对票据手写体字符进行纹理分析,在获得字符图像的特征向量之后,选用支持向量机对结果进行分类。该方法在由六十个人的手写体笔迹样本组成的集合上进行试验,取得了很好的识别效果。     

对偶基函数升阶算法

根据泛函分析中的对偶理论,给出低次Bernstein基函数的对偶基函数,根据对偶基函数的升阶算法,得到Bernstein基函数的高阶对偶基函数;这种算法与传统的算法相比,避免大量的繁琐计算,也不需要所给基函数是正交基函数,对计算机辅助几何设计及图形绘制系统的效率有重要意义.     

活体虹膜识别算法研究

对活体虹膜提出了一种新的分窗小波包分解和Hamming距离匹配相结合的识别算法,在特征提取过程中利用了奇异值分解,有效地减少了代码长度,不影响识别效果.实验结果表明,该方法计算速度快,提取特征的效果好,可用于实际的身份鉴别系统.     

2-D实值离散Gabor变换的快速算法实现

Gabor变换是揭示图象或信号进行时频分析的重要方法之一，因此在信号检测，信号识别，信号分析和处理等诸多领域应用广泛。但Gabor变换系数的求解较为复杂，计算量大，这就阻碍了Gabor变换在线应用领域作用的发挥。寻求Gabor变换的快速实现算法是当前这一领域研究较多的一个问题。本文从2-D实值离散Gabor变换（RDGT）自身特点出发，讨论了快速算法实现的一些方法。     

虹膜识别技术综述

虹膜识别技术作为一种身份识别手段具有独特的优势,是近年来国际上的研究热点．对虹膜识别系统的相关原理及算法进行了介绍,分析了目前研究中有待解决的问题,并提出了虹膜技术的研究方向及重点．     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.