共查询到10条相似文献,搜索用时 62 毫秒
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Data hiding in multiple images has been a significant research direction in information security. How to reasonably design the embedding strategy to spread the payload among multiple images is still an open issue. In this paper, we propose an embedding strategy on fusing multiple features. We utilize the typical characteristic parameters of gray level co-occurrence matrix, the image entropy and the shape parameter to describe image complexity. Furthermore, we combine with the number of cover images, the number of cover images assigned to steganographer and the size of cover image to estimate the steganographic capacity of each image. The strategy is implemented together with some state-of-the-art single image steganographic algorithms. Experimental results demonstrate that the security performance of the proposed strategy is higher than that of the state-of-the-art embedding strategy against the blind universal pooled steganalysis. 相似文献
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针对多用户多输入多输出技术上行传输系统,以最大信干噪比作为多址干扰(MAI)抑制的准则提出了一种新算法。该算法充分利用基站接收端所能获知的信道状态信息构造滤波矩阵,以抑制 MAI以及噪声带来的影响。与广泛关注的块对角化 MAI抑制算法相比,该算法考虑了噪声的影响,性能有较大提升。针对非理想信道环境,给出了本文算法的改进,仿真结果表明该算法具有优异的性能。 相似文献
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In terms of the multi-well energy representation technique, the effects of the distance between wells on the valence band structure and characteristics are analyzed for InGaAs/InGaAsP strain-compensated multiple quantum well lasers with zero net strain. The computed result shows that a coupling effect exists between the wells, causes an energy split, and affects the properties of the laser, such as the density of states, optical gain, differential gain, threshold wavelength, threshold carrier density and threshold current density. We find that when the distance between wells equals twice the thickness of the well, the effect of the distance between wells on the characteristics of the laser becomes weak. Therefore, for the practical design of lasers, it is reasonable to take the thickness of the barrier to be twice that of the well. 相似文献
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The DLTS divisor method, derived in a previous paper, is applied to multiple and overlapping DLTS peaks. An initial analysis
is made of two moderately separated peaks. Then, the same peaks are analyzed with 10 percent noise present, using four thermal
scans and no signal averaging. The results are compared with those obtained from other methods. Finally, to test the resolution,
the peaks are moved together until the method no longer applies. It is found that the divisor method successfully resolves
peaks with separation greater than 0.07 eV. 相似文献
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Pixel-value-ordering (PVO) technique is based on ranking the pixels within a block and often employed in reversible data hiding (RDH) to preserve the image fidelity. In this paper, an improved PVO-based algorithm is proposed to achieve a high-performance RDH. We formulate the PVO embedding as a problem of multiple histograms modification (MHM) and make two contributions. Firstly, the existing PVO-based algorithms are generalized in an MHM form and the systematic analysis of performance is offered by considering the parameter determination. Secondly, based on the new framework, an improved implementation of PVO embedding is proposed to adaptively determine the MHM manner by solving the distortion minimization of multiple histograms, which can handle different characteristics in image areas. Experimental results show the superiority of the new algorithm over the state-of-the-art methods. 相似文献
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In order to improve the angle measurement precision of LFM signals with a low computational complexity, a direction of arrival (DOA) estimation algorithm STFT-MI-ESPRIT is proposed in this paper. The algorithm is based on short time Fourier transform (STFT) and multiple invariance estimation of signal parameters via rotational invariance techniques (MI-ESPRIT). Firstly, the STFT of the array element’s output is calculated and the signals are transformed to the time-frequency domain. Then the spatial time-frequency distribution matrix can be obtained through selecting multiple single-source time-frequency points in the time-frequency plane and the signal subspace can also be obtained using Eigen decomposition. Finally, the multiple rotational invariant equation of the array based on STFT is obtained and the closed-form solution is obtained using the multi-least-squares (MLS) criterion. The simulation results show that the proposed algorithm can improve the estimation precision greatly compared with the traditional ESPRIT-like algorithms and its computational complexity remains the same in general. This paper also proposes that the STFT-MI-ESPRIT algorithm can use partial rotational invariances of the array instead of all the rotational invariances, which can reduce the computational complexity on the basis of ensuring the estimation precision basically. The simulation results verify the effectiveness of the conclusion. 相似文献