Γ-Z源双级矩阵变换器

针对传统的双极性矩阵变换器(TSMC)电压传输比低的缺点,提出了一种基于Γ-Z源的TSMC拓扑及其调制策略。该拓扑可通过改变变压器的匝数比来调节输出电压范围,与已有的Z源TSMC相比具有电容电压应力更低、所需电容数量少的优点。此处还对Γ-Z源TSMC的电压传输比与r-z源网络参数设计进行了分析,并搭建了一台TMS320F28335和EPM570为控制器的Γ-Z源TSMC实验样机,仿真和实验验证了所提拓扑和控制策略的可行性和优越性。

三值Read-Muller展式的最优极性

本文提出了计算3~n个不同极性Reed-Muller展式的新方法。该方法不需进行矩阵计算,即可从函数值(真值)向量直接得到3~n个RM展式.这样,不但减少了计算复杂性,且有利于较快求出RM展式的最优极性表示.

基于关系的DCT域盲水印算法

为了更好进行版权保护,提出一种基于关系的DCT域盲提取数字水印算法。首先,对原始图像进行8×8分块的离散余弦变换,根据变换后每一块内的直流系数和中频系数的关系得到一个极性矩阵,将该极性矩阵与最佳置乱处理后的二值水印图像进行对比,根据对比的结果对载体图像的中频系数进行修改达到水印嵌入的目的。在水印的提取过程中不需要原始图像,实现了水印的盲提取。大量的仿真实验结果表明了该算法的有效性。

Ground roll attenuation using a time-frequency dependent polarization filter based on the S transform

The ground roll and body wave usually show significant differences in arrival time, frequency content, and polarization characteristics, and conventional polarization filters that operate in either the time or frequency domain cannot consider all these elements. Therefore, we have developed a time-frequency dependent polarization filter based on the S transform to attenuate the ground roll in seismic records. Our approach adopts the complex coefficients of the S transform of the multi-component seismic data to estimate the local polarization attributes and utilizes the estimated attributes to construct the filter function. In this study, we select the S transform to design this polarization filter because its scalable window length can ensure the same number of cycles of a Fourier sinusoid, thereby rendering more precise estimation of local polarization attributes. The results of applying our approach in synthetic and real data examples demonstrate that the proposed polarization filter can effectively attenuate the ground roll and successfully preserve the body wave.

Robust L_2-L_∞ filtering with pole constraint in a disk via parameter-dependent Lyapunov functions

Addresses the design problems of robust L2-L∞ filters with pole constraint in a disk for uncertain continuous-time linear systems. The uncertain parameters are assumed to belong to convex bounded domains. The aim is to determine a stable linear filter such that the filtering error system possesses a prescribed L2-L∞ noise attenuation level and expected poles location. The filtering strategies are based on parameter-dependent Lyapunov stability results to derive new robust L2-L∞ performance criteria and the regional pole placement conditions. From the proposed multi-objective performance criteria, we derive sufficient conditions for the existence of robust L2-L∞ filters with pole constraint in a disk, and cast the filter design into a convex optimization problem subject to a set of linear matrix inequality constraints. This filtering method exhibits less conservativeness than previous results in the quadratic framework. The advantages of the filter design procedures are demonstrated by means of numerical examples.

Weighted Polar Decomposition

In this paper,a new matrix decomposition called the weighted polar decomposition is considered.Two uniqueness theorems of weighted polar decomposition are presented,and the best approximation property of weighted unitary polar factor and perturbation bounds for weighted polar decomposition are also studied.

Towards skin polarization characterization using polarimetric technique

Measurement of optical properties of skin is an expanding and growing field of research.Recent studies have shown that the biological tissue,especially skin,changes the polarization state of the incident light.Using this property will enable the study of abnormalities and diseases that alter not only the light intensity but also its polarization state.In this paper we report an experimental study for measuring changes of polarization state of the light scattered from a phantom similar to a sample model of scattering skin.Using the notation of Stokes vector for the polarized light and Mueller matrix for the sample with its polarization properties,we have shown that some elements of the matrix were particularly sensitive to the changes of the polarization-altering physical properties of the scatterers within the phantom.

Anisotropic Hardy-Lorentz spaces and their applications

Let p ∈(0, 1], q ∈(0, ∞] and A be a general expansive matrix on Rn. We introduce the anisotropic Hardy-Lorentz space H^(p,q)_A(R^n) associated with A via the non-tangential grand maximal function and then establish its various real-variable characterizations in terms of the atomic and the molecular decompositions, the radial and the non-tangential maximal functions, and the finite atomic decompositions. All these characterizations except the ∞-atomic characterization are new even for the classical isotropic Hardy-Lorentz spaces on Rn.As applications, we first prove that Hp,q A(Rn) is an intermediate space between H^(p1,q1)_A(Rn) and H^(p2,q2)_A(R^n) with 0 < p1 < p < p2 < ∞ and q1, q, q2 ∈(0, ∞], and also between H^(p,q1)_A(Rn) and H^(p,q2)_A(R^n) with p ∈(0, ∞)and 0 < q1 < q < q2 ∞ in the real method of interpolation. We then establish a criterion on the boundedness of sublinear operators from H^(p,q)_A(R^n) into a quasi-Banach space; moreover, we obtain the boundedness of δ-type Calder′on-Zygmund operators from H^(p,∞)_A(R^n) to the weak Lebesgue space L^(p,∞)(R^n)(or to H^p_A(R^n)) in the ln λcritical case, from H^(p,q)_A(R^n) to L^(p,q)(R^n)(or to H^(p,q)_A(R^n)) with δ∈(0,(lnλ)/(ln b)], p ∈(1/(1+,δ),1] and q ∈(0, ∞], as well as the boundedness of some Calderon-Zygmund operators from H^(p,q)_A(R^n) to L^(p,∞)(R^n), where b := | det A|,λ_:= min{|λ| : λ∈σ(A)} and σ(A) denotes the set of all eigenvalues of A.