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本文以完全二叉树理论的可量词消去为基础,介绍了该理论的可数原子模型 及饱和模型,并计算了一元、二元完全型的CB秩,从而给出了CB秩在该理论中的 几何解释. 相似文献
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完全二叉树模型中元素的CB秩 总被引:4,自引:2,他引:2
本文以完全二叉树理论的可量词消去为基础,介绍了该理论的可数原子模型 及饱和模型,并计算了一元、二元完全型的CB秩,从而给出了CB秩在该理论中的 几何解释. 相似文献
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李西宁 《纯粹数学与应用数学》2002,18(1):32-35
对大型投入产出系统进行经济结构分析,需要考虑对投入产出系统的分解,由最终产品确定总产品,需要计算完全需要系数矩阵(I-A)^-1。由于投入产出系统的分析和计算的工作量主要集中于(I-A)^-1,本文给出了矩阵(I-A)^-1的简化计算方法,它具有非常的实际意义。 相似文献
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罗桂美 《数学的实践与认识》2016,(20):54-61
基于PAB(Pay-As-Bid)竞价机制,探讨不完全信息情况下供需关系对房屋成交价格的影响.在购房者对房屋价格预期不确定和购房者有限理性的假设下,利用鲁棒优化技术和演化博弈论中的"复制动态"思想,提出鲁棒演化博弈均衡的概念,建立相应的复制动态系统,并对系统的鲁棒演化均衡的渐进稳定性进行分析,得到在不同市场供需情况下购房者价格策略演化的一般规律.最后选用数值算例对模型加以验证. 相似文献
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关于矩阵乘法的一个改进算法的时间复杂度 总被引:2,自引:0,他引:2
两个n阶非负整数方阵相乘,常规算法的时间复杂度为O(n3),文献[1]提出一个“运算次数”为O(n2)的“最佳”算法,文献[2]对此算法做了进一步研究,提出三种改进策略.本文根据算法分析理论,得出改进后的算法的时间复杂度仍不低于O(n3logn),因而其阶仍高于常规算法的运算量的阶. 相似文献
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针对中药材供给中的信息不对称性,建立了三个中药材供给方与政府稽查部门之间的三个不完全信息动态博弈模型,得到了相应的子博弈精炼贝叶斯均衡解的五个结论.这五个结论合理刻画了中药材供给方与政府稽查部门的博弈行为并揭示了非法采挖野生中药材现象难以杜绝的原因.结果表明,政府对稽查行为的条件激励措施并不能有效杜绝非法采挖野生中药材现象,只有政府对所有的稽查行为实施普遍的强激励机制才可从根本上消除非法采挖野生中药材的现象. 相似文献
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在C~n中有界凸Reinhardt域上讨论了一类介于凸映射类与星形映射类之间的“完全准凸映射类”.特别地,在C~n中的多圆柱上给出了完全准凸映射的分解定理,得到了多圆柱上判别凸映射的一个改进的充分条件. 相似文献
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研究无原子布氏代数的计算复杂性 .得到了下面的新定理 :定理 1 无原子布氏代数理论Δ具有完全的量词消去法 ,也就是说每一个式子都Δ等价于一个开式子 .定理 2 无原子布氏代数的初等型Γ (x1,… ,xn)是由型内的不含量词的全体开式子所唯一决定 .定理 3 无原子布氏代数的一个长度为 n的语句的判断过程所消耗的 Turing时间和空间都是属于 2 2 cn指数级 . 相似文献
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Robert M. Corless 《Numerical Algorithms》2002,31(1-4):115-124
The cost of solving an initial value problem for ordinary differential equations to accuracy 2 is polynomial in ln. Adaptive step-size control is never theoretically more costly than fixed step-size control, and can be an unbounded factor less costly. These results contradict the standard theory, but are based on more realistic assumptions. 相似文献
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Mikhail Yu. Khachay 《Journal of Mathematical Modelling and Algorithms》2007,6(4):547-561
Two special cases of the Minimum Committee Problem are studied, the Minimum Committee Problem of Finite Sets (MCFS) and the
Minimum Committee Problem of a System of Linear Inequalities(MCLE). It is known that the first of these problems is NP-hard (see (Mazurov et al., Proc. Steklov Inst. Math., 1:67–101, 2002)). In this paper we show the NP-hardness of two integer optimization problems connected with it. In addition, we analyze the hardness of approximation to
the MCFS problem. In particular, we show that, unless NP⊂TIME(n
O(loglogn
)), for every ε>0 there are no approximation algorithms for this problem with approximation ratio (1–ε)ln (m–1), where m is the number of inclusions in the MCFS problem. To prove this bound we use the SET COVER problem, for which a similar result
is known (Feige, J. ACM, 45:634–652, 1998). We also show that the Minimum Committee of Linear Inequalities System (MCLE) problem is NP-hard as well and consider an approximation algorithm for this problem.
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Let X
n be either the symmetric group on n letters, the set of planar binary n-trees or the set of vertices of the (n – 1)-dimensional cube. In each case there exists a graded associative product on
n0
K[X
n]. We prove that it can be described explicitly by using the weak Bruhat order on S
n, the left-to-right order on planar trees, the lexicographic order in the cube case. 相似文献
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V. M. Petrogradskii 《Mathematical Notes》2000,68(5-6):751-759
Let
be the sequence of codimension growth for a variety V of associative algebras. We study the complexity function
, which is the exponential generating function for the sequence of codimensions. Earlier, the complexity functions were used to study varieties of Lie algebras. The objective of the note is to start the systematic investigation of complexity functions in the associative case. These functions turn out to be a useful tool to study the growth of varieties over a field of arbitrary characteristic. In the present note, the Schreier formula for the complexity functions of one-sided ideals of a free associative algebra is found. This formula is applied to the study of products of T-ideals. An exact formula is obtained for the complexity function of the variety U
c of associative algebras generated by the algebra of upper triangular matrices, and it is proved that the function
is a quasi-polynomial. The complexity functions for proper identities are investigated. The results for the complexity functions are applied to study the asymptotics of codimension growth. Analogies between the complexity functions of varieties and the Hilbert--Poincaré series of finitely generated algebras are traced. 相似文献
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Investigating the principle of equivalent utility under Cumulative Prospect Theory, Kałuszka and Krzeszowiec (2012) established characterizations of several important properties of the premium. It turns out that the results concerning positive homogeneity and comonotonic additivity are in general not true. The aim of this paper is to present modified and essentially generalized versions of the mentioned above results. 相似文献
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Irenée Briquel 《Discrete Applied Mathematics》2011,159(1):1-14
We study representations of polynomials over a field K from the point of view of their expressive power. Three important examples for the paper are polynomials arising as permanents of bounded tree-width matrices, polynomials given via arithmetic formulas, and families of so called CNF polynomials. The latter arise in a canonical way from families of Boolean formulas in conjunctive normal form. To each such CNF formula there is a canonically attached incidence graph. Of particular interest to us are CNF polynomials arising from formulas with an incidence graph of bounded tree- or clique-width.We show that the class of polynomials arising from families of polynomial size CNF formulas of bounded tree-width is the same as those represented by polynomial size arithmetic formulas, or permanents of bounded tree-width matrices of polynomial size. Then, applying arguments from communication complexity we show that general permanent polynomials cannot be expressed by CNF polynomials of bounded tree-width. We give a similar result in the case where the clique-width of the incidence graph is bounded, but for this we need to rely on the widely believed complexity theoretic assumption #P?FP/poly. 相似文献
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Consider K ≥ 2 independent copies of the random walk on the symmetric group SN starting from the identity and generated by the products of either independent uniform transpositions or independent uniform neighbor transpositions. At any time $n\in \mathbb{N}$, let Gn be the subgroup of SN generated by the K positions of the chains. In the uniform transposition model, we prove that there is a cut‐off phenomenon at time N ln(N)/(2K) for the non‐existence of fixed point of Gn and for the transitivity of Gn, thus showing that these properties occur before the chains have reached equilibrium. In the uniform neighbor transposition model, a transition for the non‐existence of a fixed point of Gn appears at time of order $N^{1+\frac{2}{K}}$ (at least for K ≥ 3), but there is no cut‐off phenomenon. In the latter model, we recover a cut‐off phenomenon for the non‐existence of a fixed point at a time proportional to N by allowing the number K to be proportional to ln(N). The main tools of the proofs are spectral analysis and coupling techniques. © 2011 Wiley Periodicals, Inc. Random Struct. Alg., 2012 相似文献
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A general form of Jordan-type double inequality for the generalized and normalized Bessel functions 总被引:1,自引:0,他引:1
Ling Zhu 《Applied mathematics and computation》2010,215(11):3802-3810
In this note, a general form of Jordan-type double inequality involving the generalized and normalized Bessel functions is presented, and then some recent results concerning generalized and sharp work of Jordan’s inequality are extended. At the same time, the applications of the results above give two new infinite series for sinx/x and sinhx/x. 相似文献