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281.
Yu-liang Shi Yu Chen Zhong-min Zhou Li-zhen Cui 《Journal of Signal Processing Systems》2017,89(1):27-39
Nowadays big data security plays a major issue in cloud computing. Chunk-confusion-based privacy protection mechanism (CCPPM) protects the privacy of the tenants in plaintext. But both multi-tenant applications’ data and tenants’ privacy requirements are dynamically changing, which will have a great effect on the underlying storage model of cloud data. Moreover, the tenants’ business processing will change the data distribution and destroy the distribution balance of privacy data, which makes the data stored in the cloud face the risk of leakage of privacy. Therefore, the paper proposed a privacy protection evaluation mechanism for dynamic data based on CCPPM. The paper firstly introduces three kinds of the privacy leakages due to unbalanced data under the CCPPM, and analyzes two methods used for attacking. Aiming at the privacy leakages and the attack methods, we proposed a dynamic data processing algorithm to record the tenants’ operation sequence and set up the corresponding evaluation formula. Next, we evaluated the effect of privacy protection from two aspects of simple attack and background-knowledge-based attack, and used the data distribution similarity privacy preserving dynamic evaluation algorithm presented in this paper to obtain the measurement results of privacy leakages. Finally, according to the evaluation results, the defense strategies are given to prevent data privacy leakages. The experimental evaluation proves that rationality of dynamic the evaluation mechanism proposed in this paper has better feasibility and practicality for big data privacy protection. 相似文献
282.
Acta Mathematicae Applicatae Sinica, English Series - This paper introduces two local conditional dependence matrices based on Spearman’s ρ and Kendall’s τ given the condition... 相似文献
283.
Dr. Christian Dubiella Dr. Haissi Cui Prof. Dr. Michael Groll 《Angewandte Chemie (International ed. in English)》2016,55(42):13330-13334
Electrophiles are commonly used for the inhibition of proteases. Notably, inhibitors of the proteasome, a central determinant of cellular survival and a target of several FDA‐approved drugs, are mainly characterized by the reactivity of their electrophilic head groups. We aimed to tune the inhibitory strength of peptidic sulfonate esters by varying the leaving groups. Indeed, proteasome inhibition correlated well with the pKa of the leaving group. The use of fluorophores as leaving groups enabled us to design probes that release a stoichiometric fluorescence signal upon reaction, thereby directly linking proteasome inactivation to the readout. This principle could be applicable to other sulfonyl fluoride based inhibitors and allows the design of sensitive probes for enzymatic studies. 相似文献
284.
Wenhe Du Jingxuan Yang Zhongmin Yao Junguo Lu Daosen Liu Quanling Cui 《Journal of Russian Laser Research》2014,35(4):416-423
Both increasing experimental evidence and some results of theoretical investigation have shown that there exist two kinds of turbulence in the aerosphere, Kolmogorov and non-Kolmogorov turbulence. Thus, it is necessary to improve the theory of optical wave propagation through atmospheric turbulence, namely, study the laser-beam propagation in non-Kolmogorov turbulence, before analyzing the joint influence of the Kolmogorov turbulence and non-Kolmogorov one on satellite laser communication. The beam wander will lead to the performance degradation of satellite laser communication systems and exert an influence on the achievement and stability of its links. In this paper, we consider a theoretical power spectrum of refractive-index fluctuations with a generalized power law in order to derive the variance of Gaussian-beam wave wander in weak turbulence for a horizonal path and analyze the influence of spectral power-law variations on the beam wander. We show that the expression for the beam-wander variance is of concise closed form and independent of the optical wavelength. 相似文献
285.
This paper proposes a novel method to obtain frequency modulation (FM) signals from a single fringe pattern for phase retrieval. First, a 1D discrete Meyer wavelet is employed to decompose the pattern image signal row by row and the soft-thresholding approach is applied to remove noise. The low frequency coefficients of the wavelet decomposition are then set to 0, and the signal is reconstructed. Moreover, the optimal wavelet decomposition level is adaptively determined using a cost function-based method. The reconstructed signal, which no longer contains a background component, is normalized using a nonlinear and piecewise normalization method. The proposed method is faster and more accurate than some other phase retrieval approaches, which is illustrated with two test cases. 相似文献
286.
阿尔茨海默病(AD)和轻度认知功能损伤(MCI)具有患者多、诊断难的特点,改进BP神经网络,提出自适应BP神经网络(ABP)进行100次AD和MCI诊断模拟,ABP神经网络的诊断正确率显著高于BP和RBF神经网络.采用留一法将101例正常人、200例MCI和90例AD患者的样本分为训练集和检测集,用ABP神经网络对其进行诊断模拟,总正确率达到73.91%. 相似文献
287.
随着社会和科技的不断发展,计算机的应用已经很普及,本文针对任务驱动法进行概述,分析了任务驱动法在高校计算机基础课程中的实践,提出了要明确教学目标、及时对学生进行指导、及时进行纠错,发现教学难点、及时进行归纳总结的实践方法。 相似文献
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