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A novel image encryption scheme based on Keplers third law and random Hadamard transform 被引量:3
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作者 罗玉玲 周戎龙 +2 位作者 刘俊秀 丘森辉 曹弋 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期146-159,共14页
In this paper, a novel image encryption scheme based on Keplers third law and random Hadamard transform is proposed to ensure the security of a digital image. First, a set of Kepler periodic sequences is generated to ... In this paper, a novel image encryption scheme based on Keplers third law and random Hadamard transform is proposed to ensure the security of a digital image. First, a set of Kepler periodic sequences is generated to permutate image data, which is characteristic of the plain-image and the Keplers third law. Then, a random Hadamard matrix is constructed by combining the standard Hadamard matrix with the hyper-Chen chaotic system, which is used to further scramble the image coefficients when the image is transformed through random Hadamard transform. In the end, the permuted image presents interweaving diffusion based on two special matrices, which are constructed by Kepler periodic sequence and chaos system. The experimental results and performance analysis show that the proposed encrypted scheme is highly sensitive to the plain-image and external keys, and has a high security and speed, which are very suitable for secure real-time communication of image data. 展开更多
关键词 Kepler&#39s third law random hadamard transform interweaving diffusion security
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新的求解大规模线性最小二乘问题的随机算法 被引量:1
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作者 董银丽 李鹏程 《宝鸡文理学院学报(自然科学版)》 CAS 2014年第2期15-19,共5页
目的针对传统的求解线性最小二乘问题方法的计算、存储复杂度大,不适于大规模问题的缺点,提出新的随机算法近似求解大规模线性最小二乘问题。方法通过随机采样对超大规模线性最小二乘问题的系数矩阵进行约减,利用快速Walsh-Hadamard对... 目的针对传统的求解线性最小二乘问题方法的计算、存储复杂度大,不适于大规模问题的缺点,提出新的随机算法近似求解大规模线性最小二乘问题。方法通过随机采样对超大规模线性最小二乘问题的系数矩阵进行约减,利用快速Walsh-Hadamard对问题进行变换来保留原问题的重要信息,再用QR分解算法求解约减问题,得到原问题的近似解。结果该方法有效降低了问题的求解复杂度和存储复杂度。结论数值实验表明新算法和相关算法相比求解精度可接受,但大大减少求解时间且在同等计算平台下可处理更大规模的问题。 展开更多
关键词 最小二乘问题 随机算法 Walsh-hadamard变换 QR分解
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