共查询到20条相似文献，搜索用时 140 毫秒
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随着计算机技术的发展 ,特别是密码学的发展 ,判定所给自然数ｎ是否是素数这一问题 ,不仅在理论上有重要意义 ,而且在实践中也具有很高的应用价值。本文就素数判定问题的一些常用算法给出比较和分析。所谓素数 ,是指除了能被 1和它本身整除而不能被其他任何数整除的数。根据素数的定义 ,只需用 2到ｎ - 1去除ｎ ,如果都除不尽则ｎ是素数 ,否则 ,只要其中有一个数能除尽则ｎ不是素数 ,结束循环。由此得出算法 1。算法 1(原始解法 )(1)ｆｌａｙ =0 ,ｉ=2 / ｆｌａｙ为标志 ,其初值为 0 ,只要有一个数除尽 ,其值变为 1。(2 )ｉｆｎｍｏｄｉ=… 相似文献
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李伟 《数学学习与研究(教研版)》2010,(6):107-107
大家知道2,3,5,7,11,13等素数的倍数是有判定方法的．但是17的倍数的判定方法却不常见．本文找到了一个能否被17整除的新的判定方法． 相似文献
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李明玉 《渭南师范学院学报》2013,(12):16-24
定义了奇素数函数和简化素数函数,证明了奇素数函数的值域是奇素数全集,简化素数函数的值域是不小于5的素数集合.同时应用这一结果,给出了素数判别函数,分析了孪生素数、梅森素数、费马素数、高斯素数、艾森斯坦素数、等差素数、偶变量素数、奇变量素数等的分布规律.说明了素数除了偶素数2之外,奇素数及其各类素数都有分布规律. 相似文献
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[竞赛要求] <初中数学竞赛大纲>对本章的要求:十进制整数及表示方法;整除性,被2,3,4,5,8,9,11等数整除的判定;素数和合数,最大公约数与最小公倍数;奇数和偶数,奇偶性分析;有余数除法和利用余数分类;完全平方数:因数分解的表示法.约数个数的计算. 相似文献
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郑云湖 《数学学习与研究(教研版)》2009,(9):105-107
根据对自然数的排列,可得到两个含有素数的数列.从这两个数列中找出内在联系,归纳出两个素数函数.由于某些素数相差2这一性质,可得到孪生素数对函数.运用这些函数可以轻松方便地找到任一素数. 相似文献
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Lin Zhou Gang Peng Hong-Ying Zheng I-Fan Su William S-Y. Wang 《Reading and writing》2013,26(6):967-989
Most sinograms (i.e., Chinese characters) are phonograms (phonetic compounds). A phonogram is composed of a semantic radical and a phonetic radical, with the former usually implying the meaning of the phonogram, and the latter providing cues to its pronunciation. This study focused on the sub-lexical processing of semantic radicals which are themselves free standing sinograms. Two primed naming experiments were carried out to examine whether the meanings and pronunciations of the semantic radicals embedded in phonograms were activated or not during sinogram recognition. In Experiment 1, semantically opaque phonograms were used as primes. We observed facilitatory priming effects for targets which were semantically related to the semantic radicals embedded in primes, but not to the primes themselves. These effects were present for low-frequency primes, but not for high-frequency primes. Experiment 2 used only low-frequency phonograms as primes. We observed facilitatory priming effects for targets which were homophones of the semantic radicals embedded in primes, but not of the primes themselves. These results suggest that sub-lexical semantic and phonological information of semantic radicals are activated, and that the activation processes are modulated by the lexical frequency of the host phonograms. Our study shows that sub-lexical processing of semantic radicals is similar to that of phonetic radicals, indicating no fundamental difference between sub-lexical processing of semantic and phonetic radicals, supporting the view that a radical has a unique representation irrespective of its function in the orthographic system of Taft’s model. 相似文献
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邱润民 《商丘师范学院学报》2002,18(5):112-117
六生素数是首次定义的多生素数。本文一反数坛惯用部分思维的常规，而是运用整体思维来解决问题：即不估计不超过任意正整数N有多少六生素数，而是直接着眼于全体正整数列来判断六生素数是否无限多。 相似文献
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Korean has visually salient syllable units that are often mapped onto either prefixes or suffixes in derived words. In addition, prefixed and suffixed words may be processed differently given a left-to-right parsing procedure and the need to resolve morphemic ambiguity in prefixes in Korean. To test this hypothesis, four experiments using the masked priming lexical decision paradigm were conducted. Results showed that suffixed primes facilitated responses to their stem targets regardless of the lexicality or interpretability of the primes. In contrast, prefixed primes had a significant effect only when they were real words, and not when they were either interpretable or noninterpretable prefixed pseudowords. These results suggest that there may be two different processing mechanisms for derived words in Korean. One is prelexical morphological decomposition for suffixed words, and the other is the supralexical analysis for prefixed words where decomposition occurs only after the whole word has been accessed. 相似文献
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This study investigated the development of automatic word recognition processes, in particular the development of the morphological
level of processing. We examined masked priming of Hebrew irregular forms at two levels of reading experience. Both third-
and seventh-grade children showed morphological priming for defective roots when primes and targets conformed to the canonical
morphological structure, containing all three letters of the roots, and also when the surface form of the primes and targets
contained only two of the root letters. However, priming was not observed when primes and targets did not overlap in the surface
form of the roots, i.e. the full three-letter root as prime and only two root letters in the target. These results suggest
that both tri- and bi-consonantal representations of defective roots exist in the mental lexicon of young readers. The formation
of interconnections between these allomorphic representations, however, requires more extensive reading experience. 相似文献
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第45和46个梅森素数的预测 总被引：1，自引：0，他引：1
根据已发现的44个梅森素数,运用非线性拟合,给出了梅森素数分布的猜想,由此得到第45和46个梅森素数的范围和可能值,即％中声取自然对数的范围是[0．396283124964472n-0．251065835613184,0．396283124964472n＋1．3570453473079]． 相似文献
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This study investigates the relative roles of internal and external letter features in word recognition. In Experiment 1 the efficacy of outer word fragments (words with all their horizontal internal features removed) was compared with inner word fragments (words with their outer features removed) as primes in a forward masking paradigm. These forward masked primes were followed by a word to be read aloud. Outer word primes presented for longer durations produced significantly faster naming responses than inner primes. Outer parts of words appear to provide more relevant information for lexical access at an earlier stage than inner fragments. In Experiment 2 words with only external features were named correctly on 96% of occasions compared with 52% of words with only their inner features presented. This indicates much greater information content in the periphery of a word (despite having a reduced area of print available: 45% compared to 55%). Multiple regression analyses controlling for ‘guessability’ (from data in Experiment 2) still produced significantly faster reaction times in the outer relative to the inner priming condition for longer prime durations. These experiments demonstrate that first, the most informative letter features are concentrated in the peripheral region of words; and second, even controlling for this effect, readers appear to have a bias towards analysing outer features of a word before inner features. 相似文献
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Shailesh A. Shirali 《Resonance》2013,18(3):226-240
Marin Mersenne was many things: scientist, mathematician and writer. He did original work on acoustics and on prime numbers; today his name is linked to a family of primes called ‘Mersenne primes’. But his greatest contribution was his work in propagating a culture of scientific inquiry in Europe — a culture which emphasized communication and dissemination and learning from one’s peers. The work done on the cycloid illustrates this theme beautifully. This article looks at some work for which Mersenne is best known. 相似文献
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就Mersenne素数的基本理论、探寻史、分布规律、有关猜想、探究意义及相关问题的研究情况作一综述,并提出了一些有待解决的问题. 相似文献
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Leonard A. Eiserer 《Learning & behavior》1978,6(3):308-312
After rats had been trained to press a lever for food reward, experimenter-initiated food “primes” increased the likelihood of subsequent responding during periods in which the subjects were nondeprived. No such priming effects were found after presentation of a stimulus that had previously been paired with food. In other experiments, nonreinforced leverpresses, as well as subthreshold components of the leverpress response (e.g., forepaw raising), were also found to be enhanced by food primes. Taken together with other reports in the literature, the present findings are consistent with a “motivational aftereffects” interpretation of priming, and also with the notion that all stimuli which possess reinforcing properties possess priming properties as well. 相似文献