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In this paper, we consider the counting problem of matrix of set (Aij)k×n which satisfies k∪i=1 n∪j=1 Aij={a1,a2,…,am} and other conditions, and obtain some computational formulas which extend all the results in [1]. 相似文献
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《数学的实践与认识》2017,(20)
研究了一类基于集合种群网络的传染病模型.针对在疾病传播过程中,随着染病者数量的增加,被感染的人数会达到饱和,研究了带有饱和发生率的传染病模型,建立了不同集合种群之间扩散模式,并分析了模型动力学的性态,给出了无病平衡点及其稳定性和正平衡点的存在性.最后用数值模拟验证了理论结果的正确性. 相似文献
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对《全日制义务教育数学课程标准》理念部分的意见 总被引:4,自引:0,他引:4
《全日制义务教育数学课程标准(实验稿)》(以下简称《标准》)进行实验已经四年多了,现正在进行修订.趁此机会,向修订者提供一些意见和建议,谨供参考. 相似文献
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随机数在密码学、保密通信和国家安全等领域具有重要的作用,因此寻求一种提高随机数测试通过率的方法具有重要意义.对美国NIST SP800-22测试标准中的部分测试标准进行了分析,并针对其中的单比特频数测试、游程测试、块内最大游程测试以及子块测试分别给出了其物理意义和改进随机数发生器性能的硬件措施. 相似文献
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研究一类具有标准发生率的SIS传染病模型.应用微分方程定性理论,分别给出了保证该系统地方病平衡点、无病平衡点和总人口消亡平衡点全局渐近稳定的充分条件. 相似文献
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Dong Li CHEN Jing Jing FENG Chun Hui MA .School of Science Xi’an University of Architecture Technology Shaanxi P.R.China .Department of Basic Courses Xi’an Peihua University Shaanxi 《数学研究与评论》2011,31(2)
In this paper,the closeness of the τ-standard part of a set is discussed.Some related propositions of the τ-neighborhood system of a set are given.And then some related conclusions of the τ-monad of a set and the τ-standard part of a set are presented.And based on it,the necessary and sufficient conditions of the enlarged model and the saturated model are showed.Finally,some sufficient conditions that the τ-standard part of a set is closed are proved in the enlarged model and the saturated model. 相似文献
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Michael Rathjen 《Mathematical Logic Quarterly》2008,54(1):83-97
Constructive set theory started with Myhill's seminal 1975 article [8]. This paper will be concerned with axiomatizations of the natural numbers in constructive set theory discerned in [3], clarifying the deductive relationships between these axiomatizations and the strength of various weak constructive set theories. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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We deal with periodic groups saturated with dihedral groups. In particular, it is proved that periodic groups of bounded period, and also periodic Shunkov groups, saturated with dihedral groups, are locally finite.Supported by RFBR grant No. 03-01-00356 and by the Krasnoyarsk Science Foundation, project 11F0202C.Translated from Algebra i Logika, Vol. 44, No. 1, pp. 114–125, January–February, 2005. 相似文献
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In searching for cost-efficient strategies to reduce emissions from energy conversion, most western countries use energy-emission models. In these models, the whole energy conversion chain and possible future options for energy supply and emission reduction are mapped into a network of energy flows. Total discounted cost of energy supply and emission reduction is minimized under the restriction of maximum allowed emissions of SO2, NO
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, or CO2. The present paper extends one of these models to allow for fuzzy parameters. Such an extension appears to be useful when the data situation is weak. In this paper, a fuzzy linear program is developed, which has been applied to an energy-emission model of Lithuania. 相似文献
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Mauro Di Nasso 《Mathematical Logic Quarterly》1998,44(1):138-142
Assuming the existence of an inaccessible cardinal, transitive full models of the whole set theory, equipped with a linearly valued rank function, are constructed. Such models provide a global framework for nonstandard mathematics. 相似文献
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Groups Saturated by a Finite Set of Groups 总被引:1,自引:1,他引:0
We study the periodic groups that are saturated by a finite set of finite (nonabelian simple) groups, obtaining some information about the elements of the saturating set. 相似文献
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We show that if M is a countable recursively saturated model of True Arithmetic, then G = Aut(M) has nonmaximal open subgroups with unique extension to a maximal subgroup of Aut(M). Mathematics Subject Classification: 03C62, 03C50. 相似文献
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FUBINITHEOREMw.r.t.STOCHASTICMEASUREONPRODUCTMEASURABLESPACECHENPEIDE(陈培德)(InstituteofAppliedMathematics,theChineseAcademyofS... 相似文献
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We propose a set theory, called NRFST, in which the Cantorian axiom of infinity is negated, and a new notion of infinity is introduced via non standard methods, i. e. via adequate notions of standard and internal, two unary predicates added to the language of ZF. After some initial results on NRFST, we investigate its relative consistency with respect to ZF and Kawai's WNST. 相似文献
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Abstract One aspect of Manpower Planning is the investigation of wastage and internal transitions for homogeneous groups of employees in a Manpower system. In the relevant literature, the attainability of a desired stock vector was studied under control by recruitment for time-discrete Markov models. These approaches allow choosing a proper recruitment strategy, resulting in an attainable vector most similar to a desired one. In this article, this problem will be discussed under stochastic assumptions for attainability after one step. Based on fuzzy set theory, a procedure is introduced that allows evaluating and comparing recruitment strategies, resulting in the determination of a most preferable strategy. 相似文献