共查询到20条相似文献，搜索用时 437 毫秒
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数字水印技术是解决多媒体数字产品版权保护与信息完整性的有效方法。提出了一种基于离散小波变换和奇异值分解的盲数字水印算法,算法利用小波变换和矩阵奇异值本身的特性,将Arnold变换后的水印信息量化地嵌入到原始图像小波低频子带分块奇异值分解后的向量中。实验表明,该算法具有较好的透明性和鲁棒性。 相似文献
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方娜 《渭南师范学院学报》2014,(11):43-47
提出一种基于奇异值分解和离散小波变换并应用计算机生成全息图作为水印图像的新算法．该算法结合了奇异值分解抗几何攻击能力强以及离散小波变换抗噪声、压缩等能力强的特点．实验表明,该算法能有效地抵抗旋转、平移、翻转和缩放等几何攻击,同时对滤波、加噪声、JPEG压缩、图像模糊、裁剪、锐化和对比度增强等常规攻击也有很强的鲁棒性． 相似文献
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基于离散小波变换与奇异值分解提出一种新型数字水印算法,其主要目的是提供一种合适的解决方案,以降低几何攻击带来的影响。为了达到该目标,将宿主图像分为4个互不重叠的子图,然后使用DWT-SVD技术分别在其中嵌入水印。水印的冗余可以降低裁剪攻击造成的影响。此外,为了应对诸如旋转、平移等几何攻击,提出一种校正技术,通过边缘检测与对所需图像边角的获取,以重构遭受几何攻击的图像。实验结果表明,与其它水印算法相比,该方案对常见的信号处理与几何攻击都具有较强的鲁棒性。 相似文献
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针对传统视频水印算法鲁棒性和安全性较差的问题,提出了一种新的结合双树复小波变换(DT-CWT)和奇异值分解(SVD)的视频半盲水印方法。算法首先从视频中提取I帧,其数量和位置均由用户决定,具有良好的保密性。I帧的亮度分量经DT-CWT变换的系数有较强的鲁棒性、更佳的重构效果、灵活的水印嵌入位置以及更多的方向选择性,SVD分解后的奇异值具有良好的抗几何失真不变性。同时还生成了一个随机密钥,有效提高了视频水印的安全性。实验结果表明,该算法对视频质量的影响较小,并且能有效抵御高斯噪声、椒盐噪声、JPEG压缩、直方图均衡化、帧交换、帧删除及帧平均等多种攻击,具有较强的鲁棒性。 相似文献
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提出了一种新的基于DCT-SVD的数字水印算法．该算法将图像分块后,先进行离散余弦变换,再进行奇异值分解,根据数字图像进行奇异值分解后得到的奇异值序列是递减的序列这一特性来嵌入水印．提取水印时不需要原始图像,所以本水印方案是盲的．实验结果表明,该算法不仅对几何失真具有很强的抵抗能力,而且对添加噪声、滤波及JPEG压缩也具有良好的鲁棒性． 相似文献
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新的基于奇异值分解和小波变换的图像水印技术 总被引：2，自引：0，他引：2
基于传统的奇异值分解技术和小波变换技术,这里将两种技术相结合,提出了一种新的数字图像水印技术。将灰度水印图像嵌入到了载体小波变换分解后的中频子带。仿真实验结果表明,该算法比较有效,能够抵抗多种攻击,具有较好的鲁棒性和透明性。 相似文献
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提出了一种基于多小波变换的数字水印算法,将二值水印嵌入到宿主图像的多小波变换域中。首先将对应于相同位置的多小波系数形成向量序列,然后采用均值量化方法嵌入数字水印。实验结果表明,该水印算法在多种攻击下都具有较好的鲁棒性。 相似文献
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研究了彩色图像水印算法,重点研究了彩色图像空间表示和转换关系、余弦变换、基于奇异值分解算法等。提出了一种彩色水印算法,该算法将彩色图像从RGB空间转换到HSV空间,并提取饱和度S分量,对S分量进行了DCT变换,从而获取低频信息,作为水印嵌入位置;在水印嵌入过程时,采用了基于奇异值分解的算法进行嵌入水印。为了检测该算法的鲁棒性,对该算法进行了加入高斯噪声、椒盐噪声、JEPG压缩、几何等方式攻击。结果表明,该算法能有效地抵抗JPEG压缩攻击,对加入噪声攻击也表现了较好的鲁棒性。 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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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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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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Rachel Zupek 《海外英语》2007,(11):40-41
我们绝大部分人都同意一件事情——我们喜欢金钱。但是你对金钱的喜欢之情足够到让你创立一份事业么?.财富通常被人忽视,主要在于人们不能真正了 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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YANGShiguo 《重庆大学学报(英文版)》2004,3(1):86-88
The problem on the geometrc inequalities involving an n-dimensional simplex and its inscribed simplex is studied. Aninequality is established, which reveals that the difference between the squared circumradius of the n-dimensional simplex andthe squared distance between its circumcenter and barycenter times the squared circumradius of its inscribed simplex is not lessthan the 2(n-1)th power of n times its squared inradius, and is equal to when the simplex is regular and its inscribed siplex is atangent point one. Deduction from this inequality reaches a generalization of n-dimensional Euler inequality indicating that thecircumradius of the simplex is not less than the n-fold inradius. Another inequality is derived to present the relationship betweenthe circumradius of the n-dimensional simplex and the circumradius and inradius of its pedal simplex. 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