共查询到20条相似文献,搜索用时 62 毫秒
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本文探讨了布尔"复合函数"G(f1,L,fk)的有关密码学性质,分别给出了布尔"复合函数"是平衡函数、m阶相关免疫函数、(n,l.m)弹性函数,m阶广义ε-相关免疫函数的条件及其满足严格雪崩准则的条件. 相似文献
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布尔函数扩散性的矩阵刻画 总被引:1,自引:0,他引:1
该文利用布尔函数的特征矩阵, 给出了n(3) 元布尔函数在sGFn(2) 满足扩散准则的充分必要条件, 在此基础上得到了布尔函数满足严格雪崩准则(SAC)的一个充分必要条件和n元平衡布尔函数满足严格雪崩准则、代数次数达到最大且不含有非零线性结构的一个充分必要条件, 最后提出了平衡且满足严格雪崩准则的布尔函数的两种特殊的递补构造法。 相似文献
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性能好的布尔函数的研究 总被引:2,自引:0,他引:2
张文政 《信息安全与通信保密》1997,(3)
对n(n=3,4,5)个变量的布尔函数进行了研究,得出了满足平衡性、相关免疫性、SAC和高的代数式次数的布尔函数的精确数目,利用它们可以构造出满足上述特性的任意n(n>5)个变量的布尔函数。 相似文献
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利用t+1个n元布尔函数(称为基函数)级联构造了一类n+t元布尔函数G(x,y),并给出了G(x,y)的Walsh循环谱和自相关系数。通过Krawtchouk多项式与Krawtchouk矩阵对G(x,y)和基函数的关系进行了研究。分析了G(x,y)的密码学性质:相关免疫性、扩散性和代数免疫性。特别地,当t=2时,分析了G(x,y)与基函数的具体关系。另外,一般化该构造方法构造了一类多输出布尔函数,给出了该类多输出布尔函数的广义Walsh循环谱,进而分析了该类多输出布尔函数的相关免疫性和代数免疫性。 相似文献
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文章给出了寻找布尔函数低次零化子的几个算法。在分析布尔函数的代数次数与特征矩阵关系的基础上,算法利用布尔函数与其零化子的取值关系来寻找其低次零化子。利用这些算法可以得到布尔函数的所有低次零化子,也可用到其中若干个,利用算法1还可以计算任意一个布尔函数的代数免疫度。 相似文献
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该文首先给出了一种新的求布尔函数代数次数d的零化子的算法,并且利用布尔函数的特征矩阵得到了低次零化子存在性的判别条件。其次,该文通过研究(5,1,3,12)旋转对称饱和最优函数的代数免疫和一类构造函数的代数免疫,证明了一类函数为代数攻击不变量,并对此性质作了进一步推广。 相似文献
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布尔函数的处理效果取决于布尔函数的表达形式,二元决策图(BDD:Binary decisiondiagram)是布尔函数的图的表达形式,它能对布尔函数进行高效处理。本文将阐述一种更加有效的布尔函数处理技术,它使用具有属性边的共享二元决策图(SBDD:Shared Binary Decision Diagram)。此方法包括对输入变量的编序算法和对任意项的处理方法。最后将给出用此方法进行布尔函数运算的实验结果。 相似文献
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Beverley Christian Alexandre Romanov Irina Romanova Laura J. Turbini 《Journal of Electronic Materials》2014,43(11):4199-4213
Over the last few years, 85 cell phones have been disassembled, ground up, dissolved, and analyzed for elemental content, mainly for information about the metals present in the phones, but also for some metalloids and nonmetals. The following list of 38 elements were detected in some or all of the phones: Be, B, Mg, Al, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Y, Nb, Pd, Ag, In, Sn, Sb, Te, Ba, Ta, W, Pt, Au, Tl, Pb, Bi, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Er. Cadmium was never detected. This paper discusses the methods used for carrying out the analysis, proposes possible sources in the telephones for the elements of interest, the reasons for the interest in most of the elements, and method repeatability. 相似文献
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《IEEE transactions on information theory / Professional Technical Group on Information Theory》2005,51(9):3186-3199
A binary sequence satisfies a one-dimensional$(d_1, k_1, d_2, k_2)$ runlength constraint if every run of zeros has length at least$d_1$ and at most$k_1$ and every run of ones has length at least$d_2$ and at most$k_2$ . A two-dimensional binary array is$(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$ -constrained if it satisfies the one-dimensional$(d_1, k_1, d_2, k_2)$ runlength constraint horizontally and the one-dimensional$(d_3, k_3, d_4, k_4)$ runlength constraint vertically. For given$d_1, k_1, d_2, k_2, d_3, k_3, d_4, k_4$ , the two-dimensional capacity is defined as $$displaylines C(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4) hfillcr hfill=, lim_m,n rightarrow infty log_2 N(m, n ,vert, d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)over mn $$ where $$N(m, n ,vert, d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$$ denotes the number of$m times n$ binary arrays that are$(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$ -constrained. Such constrained systems may have applications in digital storage applications. We consider the question for which values of$d_i$ and$k_i$ is the capacity$C(d_1, k_1, d_2, k_2; d_3, k_3, d_4, k_4)$ positive and for which values is the capacity zero. The question is answered for many choices of the$d_i$ and the$k_i$ . 相似文献
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单片机体积小、重量轻、抗干扰能力强、环境要求不高、价格低廉、可靠性高、灵活性好、深受初学者喜欢。以STC90C58为核心控制芯片,DS1302为时钟芯片,DS18B20采集温度,完成多功能电子时钟的设计。该设计能够准确显示年、月、日、星期、时、分、秒及温度,通过按键可以调整年、月、日、星期、时、分、秒、12/24小时转换、整点提示以及闹钟,还可显示阴阳历。 相似文献
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Better breast cancer detection 总被引:2,自引:0,他引:2
《Spectrum, IEEE》2001,38(5):50-54
X-rays go digital, computers read film, and chemicals mark tumors, but will these new technologies make it in the clinic? The imaging technologies considered for breast cancer include film-screen mammography, full field digital mammography, ultrasound, magnetic resonance imaging, scintimammography, thermography, electrical impedance imaging, optical imaging, electric potential measurement, positron emission tomography, novel ultrasound techniques, elastography, magnetic resonance spectroscopy, thermoacoustic computed tomography, microwave imaging, Hall-effect imaging and magneto-mammography 相似文献
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Continuing efforts under the auspices of the National Earthquake Hazards Reduction Program are under way to improve earthquake risk assessment and risk management in earthquake-prone regions of Alaska, California, Nevada, Washington, Oregon, Arizona, Utah, Wyoming, and Idaho, the New Madrid and Wabash Valley seismic zones in the central United States, the southeastern and northeastern United States, Puerto Rico, Virgin Islands, Guam, and Hawaii. Geologists, geophysicists, seismologists, architects, engineers, urban planners, emergency managers, health care specialists, and policymakers are having to work at the margins of their disciplines to bridge the gap between research and practice and to provide a social, technical, administrative, political, legal, and economic basis for changing public policies and professional practices in communities where the earthquake risk is unacceptable 相似文献
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Daskalov R. Hristov P. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(11):3001-3005
Sixteen new binary quasi-cyclic linear codes improving the best known lower bounds on minimum distance in Brouwer's tables are constructed. The parameters of these codes are [102, 26, 32], [102, 27, 30], [142, 35, 40], [142, 36, 38] [146, 36, 40], [170, 16, 72], [170, 20, 66], [170, 33, 52] [170, 36, 50], [178, 33, 56], [178, 34, 54], [182, 27, 64] [182, 36, 56], [186, 17, 76], [210, 23, 80], [254, 22, 102] Sixty cyclic and thirty quasi-cyclic codes, which attain the respective bounds in Brouwer's table and are not included in Chen's table are presented as well. 相似文献
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Lei Zhang Tian Gong Zhiqiang Yu Huan Dai Zhenjingfeng Yang Ganlin Chen Jinhua Li Ruikun Pan Huide Wang Zhinan Guo Han Zhang Xiao Fu 《Advanced functional materials》2021,31(1):2005471
The emerging monoelemental 2D materials named as Xenes including borophene, silicene, germanene, stanene, phosphorene, arsenene, antimonene, bisthumene, selenene, and tellurene, have attracted rising attention experimentally and theoretically. Because of their excellent and versatile physical, chemical, electrical, and optical advantages, Xenes have been shown or have been predicted to have excellent performance in nanotechnology applications, addressing challenges and advances in electronics, energy, healthcare, and environment. In this review, the basic fundamentals in the classification of the periodic table group and the synthesis methods for the emerging materials are summarized. Then, the hybridization, doping and functionalization of 2D Xenes, and their corresponding applications are presented. Furthermore, a summary of research progress on 2D Xenes and the challenges and perspectives for their further development are discussed. 相似文献
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CompactPCI总线技术及系统设计 总被引:1,自引:1,他引:0
CompactPCI总线具有高总线带宽、高性能、支持热插拔,满足高速度、高性能尤其是复杂控制算法并要求可视化操作的应用场合的功能需求。首先,对CompactPCI总线技术在扩展性、封装和连接、被动式背板、热插拔和高性能等方面的技术特点。然后对其核心技术——热插拔技术做了简要的介绍,并在此基础上,对CompactPCI系统设计的相关问题进行了详细的论述。最后指出CompactPCI总线技术在工业、热力、石化、冶金、交通、现代通讯、核能、航空、航天、军事等领域具有广阔的应用前景。 相似文献