共查询到20条相似文献，搜索用时 62 毫秒
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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。 相似文献
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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。 相似文献
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《兰州石化职业技术学院学报》2016,(4)
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。 相似文献
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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。 相似文献
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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。 相似文献
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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. 相似文献
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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。 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F. 相似文献
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《海外英语》2007,(5):10-11
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? 相似文献
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陈美曦 《山东教育学院学报》2008,23(2):103-107
Different nations have different social cultures, and the social culture of every nation is developing with the development of the nation, language is greatly influenced by social culture, which enables language to possess national and historical characteristics. Word is the smallest, independent, meaningful linguistic unit of language. It can well reflect the national and historical characteristics. From synchronic aspect, the social and cultural influence on word meaning is mainly embodied in conceptual and associative meanings of word. The incorrespondence of word meaning is a phenomenon that exists in both conceptual and associative meanings of word among different languages. From diachronic aspect, the development of social culture causes some changes of word meaning to some extent. Therefore, social culture plays a key role in vocabulary learning and mastery of a language. 相似文献
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邱崇丙 《唐山师范学院学报》2014,(1):21-23
汉字的六书,《说文》对“转注”一类,语焉不详。后世学者提及转注,也仅限于许慎所举出的例字。《汉字例说》一文,作者从转注的角度综合考虑,对部分现代常用字作了分析,跟传统的解释有所不同。希望能抛砖引玉,互相切磋,以推进学术研究。 相似文献
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《海外英语》2007,(4):36
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. 相似文献
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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. 相似文献