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SAFER-64的弱密钥 被引量:1
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作者 侯宇 《中国计量学院学报》 2007年第1期54-58,共5页
通过对SARER-64系统基础模块的深入分析,构建了由6个线性逼近式组成的循环逼近式系统.由于循环性,该逼近式系统可以用来对任意轮次的SARER-64进行多重线性密码分析,从而确定系统的弱密钥.现以五轮SARER-64为例,构建多重线性逼近式并分... 通过对SARER-64系统基础模块的深入分析,构建了由6个线性逼近式组成的循环逼近式系统.由于循环性,该逼近式系统可以用来对任意轮次的SARER-64进行多重线性密码分析,从而确定系统的弱密钥.现以五轮SARER-64为例,构建多重线性逼近式并分析系统的弱密钥. 展开更多
关键词 弱密钥 多重线性密码分析 线性逼近式 循环逼近系统 SAFER-64
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基于图像传感器的仪表自动读数系统 被引量:11
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作者 郭永彩 刘丽君 高潮 《传感器与微系统》 CSCD 北大核心 2012年第11期115-117,121,共4页
基于图像传感器的仪表自动读数是现代测量的发展趋势。利用机器视觉和图像处理技术,设计了一种机器视觉与图像传感器测量相结合的自动读数测量系统。利用LED漫反射光源的特性设计测量用光,有效削弱仪表表面的强镜面反射,取得光照较均匀... 基于图像传感器的仪表自动读数是现代测量的发展趋势。利用机器视觉和图像处理技术,设计了一种机器视觉与图像传感器测量相结合的自动读数测量系统。利用LED漫反射光源的特性设计测量用光,有效削弱仪表表面的强镜面反射,取得光照较均匀的图像;利用移位寄存式线性逼近法从刻线群中识别出对准刻线;利用特征窗平移法提取字符特征实现了快速字符识别。实验表明:系统的测量准确性比用传统的测量方法提高了1倍,而且操作便捷,测量效率高。 展开更多
关键词 图像传感器 仪表自动读数系统 机器视觉 双排刻线特征仪表 发光二极管 移位寄存线性逼近 特征窗平移法
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Proximal Point-Like Method for Updating Simultaneously Mass and Stiffness Matrices of Finite Element Model
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作者 DAI Hua WANG Kangkang 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2020年第1期1-12,共12页
The problem of correcting simultaneously mass and stiffness matrices of finite element model of undamped structural systems using vibration tests is considered in this paper.The desired matrix properties,including sat... The problem of correcting simultaneously mass and stiffness matrices of finite element model of undamped structural systems using vibration tests is considered in this paper.The desired matrix properties,including satisfaction of the characteristic equation,symmetry,positive semidefiniteness and sparsity,are imposed as side constraints to form the optimal matrix pencil approximation problem.Using partial Lagrangian multipliers,we transform the nonlinearly constrained optimization problem into an equivalent matrix linear variational inequality,develop a proximal point-like method for solving the matrix linear variational inequality,and analyze its global convergence.Numerical results are included to illustrate the performance and application of the proposed method. 展开更多
关键词 model updating proximal point method optimal matrix pencil approximation matrix linear variational inequality
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On Approximation of Nonbounded Continuous Functions
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作者 ZHENGCheng-de WANGRen-hong 《Chinese Quarterly Journal of Mathematics》 CSCD 2003年第1期44-48,共5页
This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are ... This paper generalizes the basic principle of multiplier-enlargement approach to approximating any nonbounded continuous functions with positive linear operators, and as an example, Bernstein polynomial operators are analysed and studied. This paper gives a certain theorem as a general rule to approximate any nonbounded continuous functions. 展开更多
关键词 positive linear operator approximation of nonbounded continuous function method of multiplier-enlargement Bernstein polynomial operator
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Approximation Properties of a Class of Extremal Polynomials over Smooth Jordan Curves
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作者 谢庭藩 周颂平 朱来义 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2001年第2期185-190,共6页
There have been many elegant results discussing the approximation proper- ties of the Bieberbach polynomials. However, very few papers investigated the approxi- mation properties of the extremal polynomials over Jorda... There have been many elegant results discussing the approximation proper- ties of the Bieberbach polynomials. However, very few papers investigated the approxi- mation properties of the extremal polynomials over Jordan curves. In the present paper, some results on a class of extremal polynomials over C1+αsmooth Jordan curves are obtained. 展开更多
关键词 smooth Jordan curve extremal polynomial approximation property.
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