共查询到20条相似文献,搜索用时 0 毫秒
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Stefano Mazzanti 《Mathematical Logic Quarterly》2002,48(1):93-104
Abasisforaset C of functions on natural numbers is a set F of functions such that C is the closure with respect to substitution of the projection functions and the functions in F. This paper introduces three new bases, comprehending only common functions, for the Grzegorczyk classes ℰn with n ≥ 3. Such results are then applied in order to show that ℰn+1 = Kn for n ≥ 2, where {Kn}n∈ℕ is the Axt hierarchy. 相似文献
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We investigate the dynamics of two extensive classes of recursive sequences:xn+1=c∑ k ∑xn-ioxn-i1…xn-i2j+f(xn-io,xn-i1,…,xn-i2k)j=0(i0,i1,…,i2j)∈A2j/c∑ k ∑xn-ioxn-i1…xn-i2j-1+c+f(xn-io,xn-i1,…,xn-i2k)j=1(i0,i1,…,i2j)∈A2j-1 and xn+1=c∑ k ∑xn-ioxn-i1…xn-i2j-1+c+f(xn-io,xn-i1,…,xn-i2k)j=1(i0,i1,…,i2j)∈A2j-1/c∑ k ∑xn-ioxn-i1…xn-i2j+f(xn-io,xn-i1,…,xn-i2k)j=0(i0,i1,…,i2j)∈A2j We prove that their unique positive equilibrium x = 1 is globally asymptotically stable.And a new access is presented to study the theory of recursive sequences. 相似文献
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Siberian Mathematical Journal - 相似文献
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L. Aggoun L. Benkherouf A. Benmerzouga 《Journal of Applied Mathematics and Decision Sciences》2003,7(4):249-263
In this paper we propose a new discrete time discrete state inventory model for perishable items of a single product. Items in stock are assumed to belong to one of a finite number of quality classes that are ordered in such a way that Class 1 contains the best quality and the last class contains the pre-perishable quality. By the end of each epoch, items in each inventory class either stay in the same class or lose quality and move to a lower class. The movement between classes is not observed. Samples are drawn from the inventory and based on the observations of these samples, optimal estimates for the number of items in each quality classes are derived. 相似文献
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It is well known and important that if u ≥ 0 is subharmonic on a domain Ω in ℝ
n
and p > 0, then there is a constant C(n,p) ≥ 1 such that for each open ball B(x,r) ⊂ Ω. The definition of a relatively new function class, quasi-nearly subharmonic functions, is based on such a generalized
mean value inequality. It is pointed out that the obtained function class is natural. It has important and interesting properties
and, at the same time, it is large: In addition to nonnegative subharmonic functions, it includes, among others, Hervé’s nearly
subharmonic functions, functions satisfying certain natural growth conditions, especially certain eigenfunctions, polyharmonic
functions and generalizations of convex functions. Further, some of the basic properties of quasi-nearly subharmonic functions
are stated in a unified form. Moreover, a characterization of quasi-nearly subharmonic functions with the aid of the quasihyperbolic
metric and two weighted boundary limit results are given.
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Siberian Mathematical Journal - 相似文献
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本文讨论R.Péter[3]所提出的二重递归函数的性质,给出了二重递归函数的另一种等价刻画,即证明了二重速归函数类就是文[6]中所讨论的Z—分层函数类Z=(?).结合文[6]的结论我们便得到了关于二重递归函数类的一种Grzegorezyk型分层和一种更简单的二重递归模式. 相似文献
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This paper studies the spaces of Gateaux and Frechet Operator
Differentiable functions of a real variable and their link with the space of Operator
Lipschitz functions. Apart from the standard operator norm on B(H),
we consider a rich variety of spaces of Operator Differentiable and Operator
Lipschitz functions with respect to symmetric operator norms. Our approach
is aimed at the investigation of the interrelation and hierarchy of these spaces
and of the intrinsic properties of Operator Differentiable functions. We apply
the obtained results to the study of the functions acting on the domains
of closed *-derivations of C*-algebras and prove that Operator Differentiable
functions act on all such domains.We also obtain the following modification of
this result: any continuously differentiable, Operator Lipschitz function acts
on the domains of all weakly closed *-derivations of C*-algebras. 相似文献
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In this paper, some classes of local polynomial functions on abelian groups are characterized by the properties of their variety. For this characterization, we introduce a numerical quantity depending on the variety of the local polynomial only. Moreover, we show that the known characterization of polynomials among generalized polynomials can be simplified: a generalized polynomial is a polynomial if and only if its variety contains finitely many linearly independent additive functions. 相似文献
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给出由非标准离散函数及其差商所定义的新广义函数的某些类,它们密切联系于通常的直至某阶为连续可微的函数.周的一个深刻的定理被用来建立这些类与非标准Sobolev空间之间的关系. 相似文献
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邓冠铁 《应用泛函分析学报》2006,8(3):197-201
对包含在Hp空间上的函数准解析类Hp(Mn)的准解析问题给出了解答,这个解答与经典的Denjoy-Carleman准解析和Mandelbrojt准解析问题的解答相类似. 相似文献
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