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1.
一种小波域音频信息隐藏方法 总被引:1,自引:0,他引:1
提出了一种基于量化的小波域音频隐藏算法,将保密语音隐藏到载体音频中.为提高隐藏重和保密语音传输的安全性,对保密语音进行了小波域压缩编码和m序列的扩频调制,生成待隐藏的比特序列;通过量化方法,将编码和调制后的保密语音隐藏到载体音频的小波系数中;保密语音的恢复过程不需要使用原始音频、仿真结果表明,隐藏有保密语音的载体音频听觉质量没有明显下降,提取的保密语音感知质量较好;该算法对重量化、加噪、低通滤波等攻击均有良好的鲁棒性. 相似文献
2.
Becky Lavi Abraham Marmur 《Colloids and surfaces. A, Physicochemical and engineering aspects》2004,250(1-3):409-414
An equation for the kinetics of partial drop spreading is proposed. This equation was empirically derived from experimental data for the spreading kinetics of partially wetting liquids in terms of the wet area versus time. The equation has the form of an exponential power law (EPL), and transforms into the well-known power law for complete wetting, when the equilibrium contact angle approaches zero. The EPL fits very well available experimental data. To lend additional support to the validity of this generalized equation, it will be demonstrated that when it is transformed to present the dynamic contact angle (DCA), it fits very well DCA experimental data for other wetting processes, such as capillary flow and tape coating. 相似文献
3.
4.
Frictionless indentation responses of transversely isotropic piezoelectric film/rigid substrate systems under circular cylindrical indenter (i.e., punch), conical indenter (i.e., cone), and spherical indenter (i.e., sphere) are investigated. Both insulating and conducting indenters are considered. The technique of Hankel transformation is employed to derive the corresponding dual integral equations for the mixed boundary value indentation problems. For the two limiting cases of infinitely thick and infinitely thin piezoelectric films, closed-form solutions are obtained. For piezoelectric films of finite thickness, a numerical method is constructed to solve the dual integral equations and semi-empirical models having only two unknown parameters are proposed for the responses of indentation force, electric charge and electric potential, and contact radius. With the two parameters inferred from the numerical results, the semi-empirical formulae are found to provide good estimates of the indentation responses for the two limiting cases of infinitely thick and thin piezoelectric films, as well as those in between. The inferred parameters in the proposed semi-empirical formulae for normalized indentation force and electric charge are checked against four different piezoelectric materials and are found to be insensitive to the selection of piezoelectric materials. It is believed that the proposed semi-empirical indentation formulae are useful in developing experimental indentation techniques to extract the material properties of piezoelectric films. 相似文献
5.
Marco Caliari Marco Vianello Luca Bergamaschi 《Journal of Computational and Applied Mathematics》2007,210(1-2):56-63
We implement a second-order exponential integrator for semidiscretized advection–diffusion–reaction equations, obtained by coupling exponential-like Euler and Midpoint integrators, and computing the relevant matrix exponentials by polynomial interpolation at Leja points. Numerical tests on 2D models discretized in space by finite differences or finite elements, show that the Leja–Euler–Midpoint (LEM) exponential integrator can be up to 5 times faster than a classical second-order implicit solver. 相似文献
6.
Kazimierz?DarowickiEmail author Waldemar?Felisiak Artur?Zieliński 《Journal of mathematical chemistry》2005,38(4):701-711
Oscillations of species concentration are phenomena accompanying several types of electrochemical and purely chemical processes.
Importance of analyzing of such processes results from both scientific and practical reasons. In the paper the authors deal
with investigation of time dependent spectra of various stages of Belousov-Zhabotinsky type chemical oscillations. As the
analytical tool the discrete wavelet transform is proposed. 相似文献
7.
In Phys. Lett. A 313 (2003) 343 we have found that the
self-reciprocal Hankel transformation (HT) is embodied in quantum
mechanics by a transform between two entangled state representations
of continuum variables. In this
work we study Hankel transforms and properties of Bessel function via
entangled state representations' transformation in quantum mechanics. 相似文献
8.
Rafael Rojas-Hernndez Juan Luis Díaz-de-Len-Santiago Grettel Barcel-Alonso Jorge Bautista-Lpez Valentin Trujillo-Mora Julio Csar Salgado-Ramírez 《Entropy (Basel, Switzerland)》2022,24(7)
This paper introduces a new method of compressing digital images by using the Difference Transform applied in medical imaging. The Difference Transform algorithm performs the decorrelation process of image data, and in this way improves the encoding process, achieving a file with a smaller size than the original. The proposed method proves to be competitive and in many cases better than the standards used for medical images such as TIFF or PNG. In addition, the Difference Transform can replace other transforms like Cosine or Wavelet. 相似文献
9.
骆程 《浙江大学学报(理学版)》1987,(1)
为刻划一类权函数W,使具有N阶消失矩的函数f的Hilbert变换f满足带权L~P强型不等式Adams给出了一个充要条件。利用A_P权的性质,本文进一步完善了这个结果。 相似文献
10.