共查询到20条相似文献，搜索用时 371 毫秒
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论述了目前Matlab软件中最新版Matlab 2009的特性及应用,介绍基于Matlab 2009对信号频域处理的工具和方法,主要包括连续时间信号的傅里叶变换、傅里叶级数以及离散时间信号的傅里叶级数和傅里叶变换的分析方法,Matlab 2009傅里叶变换分析的相对误差比较. 相似文献
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提出一种在数字音频信号中嵌入水印的算法，该算法基于离散傅里叶变换域，嵌入的水印不是传统的伪随机序列形式，而是视觉可辨的二值图像。首先将二维图像降成一维序列．然后对数字音频信号作分段离散傅里叶变换，最后在离散傅里叶变换域内．通过量化分段的音频信号的频域系数嵌入水印。在水印的嵌入过程中使用了伪随机排序技术。 相似文献
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刘保童 《贵州教育学院学报》2009,20(9):1-4
不规则采样信号的谱估计是时间序列分析中的一个重要问题。为改进不规则采样信号谱估计的分辨率,提出了一种抑制非均匀离散傅里叶变换频谱泄漏的算法,通过迭代非线性估计实现不规则采样信号离散傅里叶变换的计算。实际计算试验结果显示,这种方法能有效地抑制非均匀离散傅里叶变换结果中的频谱泄漏,提高DFT频谱的分辨率。 相似文献
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利用Lab VIEW设计了频域抽样定理仿真实验。输入信号可以是参数可调的正弦信号或用户公式输入信号,频域抽样定理采用直接抽样法和离散傅里叶变换(DFT)法两种方法编程实现,实验虚拟仪器界面具有交互性好、通用性强、方便比较、验证结果正确等特点。通过理论推导和实验编程过程帮助学生将所学的知识融会贯通,有利于学生深入理解离散傅里叶变换和离散时间傅里叶变换(DTFT)之间的关系和正确应用频域抽样定理。 相似文献
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覃丹婵 《广东职业技术师范学院学报》2014,(7):12-15
主要研究了快速傅里叶变换和离散小波变换在两种不同信号中应用,对处理的结果进行了比较分析.说明在突变信号处理中,更适宜使用小波处理,而对于相对平稳的信号,应用傅里叶变换处理则更为有效. 相似文献
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从实现物理系统中采集来的数据一般采用时域来表示,给出了被采样信号的幅值和相位信息,实际上在时域中很多有用的信息隐藏着,只有当将采样信号变换到频域中后,很多有用信息才能被提取出来.将离散采样信号由时域变换到频域的一种常用算法是离散傅里叶变换(DFT),由于直接采用DFT算法效率较低,在应用中一般采用它的一种快速算法,即快速傅里叶变换(Fast Fourier Transformation).本文基于NI公司推出的虚拟仪器软件LabView2013实现快速傅里叶变换(FFT). 相似文献
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阐述了分数傅里叶变换及其应用,首先简单介绍了传统的傅里叶变换以及Namias和Shih型的分数傅里叶变换表达式,然后在此基础上,提出了对图像数据的数字水印嵌入技术的图像版权保护方法的实现,即通过原始图像信号,加密数据信号以及水印信号在频域的叠加以及傅里叶逆变换来实现图像信号的数字水印嵌入。 相似文献
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针对信号处理中常用的傅里叶变换、拉普拉斯变换、离散时间傅里叶变换、离散傅里叶级数、Z变换、离散傅里叶变换等几种重要的变换,从它们的定义、时频域表达式、物理意义、图形等方面进行了分析。总结出了这几种变换的特点及它们之间的关系． 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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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
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GUO Bao-feng Xiao Da-wei 《重庆大学学报(英文版)》2005,4(3):129-133
Using virtual reality for interactive design gives a designer an intuitive vision of a design and allows the designer to achieve a viable, optimal solution in a timely manner. The article discusses the process of making the Virtual Reality System of the Humble Administrator＇s Garden. Translating building data to the Virtual Reality Modeling Language （VRML） is by far unsatisfactory. This creates a challenge for computer designers to do optimization to meet requirements. Five different approaches to optimize models have been presented in this paper. The other methods are to optimize VRML and to reduce the file size. This is done by keeping polygon counts to a minimum and by applying such techniques as object culling and level-ofdetail switching. 相似文献
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The awareness of individualism can be traced back to the period of American Revolution when the Declaration of Independence was produced.It expressed basic beliefs concerning freedom,equality,democracy,privacy and the relationship between people and government,which were exactly what the philosophy of individualism mostly dealt with at that time.This paper is to exploit the essence of individualism by analyzing the Declaration .The analysis enables us to reconsider its significance to the issue of America human rights and foreign policies. 相似文献
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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. 相似文献