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Y. Liu D. Lin C. Cheng H. Chen T. Jiang 《International Journal of Communication Systems》2014,27(11):3223-3231
In 2009, Lee and Chang proposed an electronic t‐out‐of‐n lottery protocol over the Internet based on the Chinese remainder theorem and blind signature. However, a security flaw exists in Lee–Chang's protocol that the lottery agent and the malicious purchaser can collude to control the winning result, which is unfair for the honest participants. On the basis of a verifiable random number generated by using the Lagrange interpolation formula over a finite field, an improved t‐out‐of‐n e‐lottery protocol is proposed, which guarantees that each participant can generate the winning result equally. The improved protocol achieves public verifiability and fairness without a trusted third party and a delaying function, which makes it more robust and more efficient. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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A new method which employs compressive sensing (CS) to reconstruct the sparse spectrum is designed and experimentally demonstrated. On the basis of CS theory, the simulation results indicate that the probability of reconstruction is high when the step of the sparsity adaptive matching pursuit algorithm is confirmed as 1. Contrastive analysis for four kinds of commonly used measurement matrices:part Hadamard, Bernoulli, Toeplitz and Circular matrix, has been conducted. The results illustrate that the part Hadamard matrix has better performance of reconstruction than the other matrices. The experimental system of the spectral compression reconstruction is mainly based on the digital micro-mirror device (DMD). The experimental results prove that CS can reconstruct sparse spectrum well under the condition of 50% sampling rate. The system error 0.078 1 is obtained, which is defined by the average value of the 2-norm. Furthermore, the proposed method shows a dominant ability to discard redundancy. 相似文献
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针对动物的情绪识别问题,提出高斯混合模型在动物声音情绪识别上的应用方法。利用语音信号处理与机器学习技术,提取动物声音信号的过零率、共振峰、梅尔 频率倒谱系数3种描述动物情绪的特征参数。采用高斯混合模型对采集到的动物声音信号训练样本进行聚类分析,计算测试样本后验概率,实现动物情绪的自动识别。通过分析特征参数的权重系数组合、高斯混合数目对识别率的影响来择选最优参数。实验结果表明,经参数优化后的高斯混合模型可将动物声音情绪的识别率由84.25%提高至96.67%。 相似文献
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Gallium-titanium-zinc oxide(GTZO) transparent conducting oxide(TCO) thin films were deposited on glass substrates by radio frequency magnetron sputtering. The dependences of the microstructure and optoelectronic properties of GTZO thin films on Ar gas pressure were observed. The X-ray diffraction(XRD) and scanning electron microscopy(SEM) results show that all the deposited films are polycrystalline with a hexagonal structure and have a preferred orientation along the c-axis perpendicular to the substrate. With the increment of Ar gas pressure, the microstructure and optoelectronic properties of GTZO thin films will be changed. When Ar gas pressure is 0.4 Pa, the deposited films possess the best crystal quality and optoelectronic properties. 相似文献
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The transparent conducting titanium-gallium co-doped zinc oxide (TGZO) thin films were grown on glass substrates by radio-frequency magnetron sputtering technique. The effects of working pressure on the structural, optical and electrical properties of the films were investigated. The results show that the deposited films are polycrystalline with a hexagonal wurtzite structure and highly textured along the c-axis perpendicular to the substrate. The TGZO film prepared at the working pressure of 0.4 Pa exhibits the best crystallinity, the maximal grain size, the highest transmittance, the lowest resistivity and the highest figure of merit. The optical constants of the films were calculated using the method of optical spectrum fitting. The dispersion behavior of the films was studied by the single-electronic oscillator dispersion model. The oscillator parameters and optical bandgaps were determined. The results demonstrate that the microstructure and optoelectrical properties of the TGZO films are dependent on the working pressure. 相似文献
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In millimeter wave cellular networks,the spectrum efficiency of multi-operator dual frequency hybrid spectrum access scheme under open access mode was studied.Firstly,Poisson point process was used to model the distribution of base stations of each operator,the base station and carrier frequency were selected by users based on maximum received power criterion and high frequency carrier signal to interference plus noise ratio (SINR) threshold access criterion respectively.Secondly,the rate coverage was used as performance criteria to study the spectrum efficiency,and the theoretical expression of rate coverage was derived based on stochastic geometry theory according to channel model,path loss model and antenna model.Finally,the influence of user density,base station density and antenna gain on rate coverage was analyzed by simulation.The experimental results show that the multi-operator dual frequency hybrid spectrum access scheme has better spectrum utilization efficiency. 相似文献
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矩阵乘法是数值分析以及图形图像处理算法的基础,通用的矩阵乘法加速器设计一直是嵌入式系统设计的研究热点。但矩阵乘法由于计算复杂度高,处理效率低,常常成为嵌入式系统运算速度的瓶颈。为了在嵌入式领域更好地使用矩阵乘法,提出了基于MPSoC(MultiProcessor System-on-Chip)的软硬件协同加速的架构。在MPSoC的架构下,一方面,设计了面向硬件约束的矩阵分块方法,从而实现了通用的矩阵乘法加速器系统;另一方面,通过利用MPSoC下的多核架构,提出了相应的任务划分和负载平衡调度算法,提高了并行效率和整体系统加速比。实验结果表明,所提架构及算法实现了通用的矩阵乘法计算,并且通过软硬件协同设计实现的多核并行调度算法与传统单核设计相比在计算效率方面得到了显著的提高。 相似文献
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