首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Two-scale homogeneous functions are functions hh satisfying h(x) = \gl h(2 x)h(x) = \gl h(2 x) for some constant \gl\gl. They form a class of special functions and include homogeneous polynomials. In this article we investigate two-scale homogeneous functions that are contained in a shift-invariant space S(f)S(\phi) where f\phi is an rr-vector of functions and satisfies a vector refinement equation. The structure of these functions is analyzed. In particular, we establish a one-to-one correspondence between these two-scale homogeneous functions with order \gl\gl and the left eigenvectors of a finite matrix (derived from the mask for f\phi) associated with eigenvalue \gl\gl.  相似文献   

2.
In this paper, we give the complete classifications of isoparametric hypersurfaces in Randers space forms. By studying the principal curvatures of anisotropic submanifolds in a Randers space (N, F) with the navigation data (h, W), we find that a Randers space form (N, F, dμBH) and the corresponding Riemannian space (N, h) have the same isoparametric hypersurfaces, but in general, their isoparametric functions are different. We give a necessary and sufficient condition for an isoparametric function of (N, h) to be isoparametric on (N, F, dμBH), from which we get some examples of isoparametric functions.  相似文献   

3.
动力系统在两种尺度意义下的Lipschitz半稳定性   总被引:1,自引:0,他引:1  
金淦 《应用数学》1999,12(2):9-13
本文将半稳定性(即在某种限制条件下的稳定性)和Lipschitz稳定性,两尺度稳定性概念结合,提出动力系统的(h0,h)-半稳定和(h0,h)-Lipschitz(局部)半稳定性概念,并且Liapuno类似函数给出相应的充要条件。  相似文献   

4.
金淦 《数学进展》1996,25(5):423-432
本文将两尺度稳定性理论引入了广义控制系统,并用类Liapunov函数给出稳定和渐近稳定的充要条件。这些准则推广了关于广义控制系统和两尺度稳定性的已有结果,使我们能在一个统一的框架内研究广义控制系统稳定性。  相似文献   

5.
本文证明了锥内一类调和函数h, 若其正部h+ = max{h,0} 满足一种增长条件, 则h 能被其边界值的积分表示. 同时证明了其负部h- = max{-h,0} 也能被类似的一种增长条件所控制. 所得结论推广了解析函数和调和函数在上半空间中关于积分表示的相关结果.  相似文献   

6.
In this paper, we unify recent optimality results under directional derivatives by the introduction of new pseudoinvex classes of functions, in relation to the study of Pareto and weak Pareto solutions for nondifferentiable multiobjective programming problems. We prove that in order for feasible solutions satisfying Fritz John conditions to be Pareto or weak Pareto solutions, it is necessary and sufficient that the nondifferentiable multiobjective problem functions belong to these classes of functions, which is illustrated by an example. We also study the dual problem and establish weak, strong, and converse duality results.  相似文献   

7.
Given a complete Riemannian manifold (M, g) with nonnegative sectional curvature outside a compact subset. Let h be another Riemannian metric which is uniformly equivalent to g. It was shown that the dimension of the space of bounded harmonic functions on (M, h) is finite and is the same as of that under metric g, and the dimension of the space spanned by nonnegative harmonic functions on (M, h) is also finite and is the same as of that under metric g. Moreover, bases were constructed for both spaces on (M, h) and precise estimates were established on the asymptotic behavior at infinity for those basic functions.  相似文献   

8.
Quasi-interpolation using radial basis functions has become a popular method for constructing approximations to continuous functions in many space dimensions. In this paper we discuss a procedure for generating kernels for quasi-interpolation, using functions which have series expansions involving terms liker logr. It is shown that such functions are suitable if and only if is a positive even integer and the spatial dimension is also even.  相似文献   

9.
A complex-valued harmonic function that is univalent and sense preserving in the unit disk U can be written in the form of f = h + g,where h and g are analytic in U.We define and investigate a new class LH_λ(α,β) by generalized Salagean operator of harmonic univalent functions.We give sufficient coefficient conditions for normalized harmonic functions in the class LH_λ(α,β).These conditions are also shown to be necessary when the coefficients are negative.This leads to distortion bounds and extreme points.  相似文献   

10.
Bounded universal functions in one and several complex variables   总被引:2,自引:0,他引:2  
We show how to obtain functions that are universal for the ball of , where . The existence of our functions will follow from universality criteria, but we also show how to construct them. Then we study the connection between certain interpolating sequences, runaway automorphisms, and the existence of universal functions on domains in .   相似文献   

11.

Text

We give series expansions for the Barnes multiple zeta functions in terms of rational functions whose numerators are complex-order Bernoulli polynomials, and whose denominators are linear. We also derive corresponding rational expansions for Dirichlet L-functions and multiple log gamma functions in terms of higher order Bernoulli polynomials. These expansions naturally express many of the well-known properties of these functions. As corollaries many special values of these transcendental functions are expressed as series of higher order Bernoulli numbers.

Video

For a video summary of this paper, please click here or visit http://youtu.be/2i5PQiueW_8.  相似文献   

12.
In the present paper, we introduce an interesting subclass Kps (h)of analytic functions in the open unit disk U. For functions belonging to theclass Kps (h), basic properties such as the coefficient bounds, the distortionand growth theorems are derived. The results presented here would provideextensions of those given by Q.-H. Xu et al. [2].  相似文献   

13.
Mendelson  S. 《Positivity》2001,5(2):177-191
We investigate connections between an important parameter in the theory of Banach spaces called the -norm, and two properties of classes of functions which are essential in Learning Theory – the uniform law of large numbers and the Vapnik–Chervonenkis (VC) dimension. We show that if the -norm of a set of functions is bounded in some sense, then the set satisfies the uniform law of large numbers. Applying this result, we show that if X is a Banach space which has a nontrivial type, then the unit ball of its dual satisfies the uniform law of large numbers. Next, we estimate the -norm of a set of {0,1}-functions in terms of its VC dimension. Finally, we present a `Gelfand number' like estimate of certain classes of functions. We use this estimate to formulate a learning rule, which may be used to approximate functions from the unit balls of several Banach spaces.  相似文献   

14.
首先引入h型Stepanov 加权伪概自守函数和∞型Stepanov加权伪概自守函数的概念, 接着建立了其函数空间的完备性以及相应组合定理, 最后证明了一类非自治无穷时滞偏中立型泛函微分方程在Sp-加权伪概自守系数下加权伪概自守解的存在唯一性.  相似文献   

15.
16.
Let F and G be the respective distributions of nonnegative random variables X and Y satisfying the convex ordering. We investigate the class of functions h for which the equality E[h(X)] = E[h(Y)] guarantees F = G. It leads to extensions of some existing results and at the same time offers a somewhat simpler proof.  相似文献   

17.
The classical estimates for analytic functions in a disc are carried over to functions which are analytic in Jordan domains whose boundaries are Lipschitz and Radon curves. Singular integrals, maximal estimates, and Lusin's inequality are considered. Analytic functions, the moduli of whose boundary values satisfy the conditions of B. Muckenhoupt are studied in detail. Properties of conformal maps and their level lines connected with the Muckenhoupt conditions on the moduli of the boundary derivatives are considered. This consideration lets one give real proofs of various distortion theorems for conformal maps of Lipschitz domains.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 73, pp. 70–90, 1977.  相似文献   

18.
Summary A characterization is given of all continuous algebra homomorphisms H from the weighted space of continuous functions CV(X, E) into ℂ, where X is a completely regular Hausdorff space, E a locally convex algebra and V a family of weight functions that vanish at infinity. These homomorphisms are represented in the form H(f) = h(f(x)) with x in X and h a continuous algebra homomorphism on E. We then consider the space of homomorphisms of CV(X, E) and give some counterexamples to possible further generalizations. Entrata in Redazione il 18 febbraio 1977. ? Aspirant ? of the Belgian ? Nationaal Fonds voor Wetenschappelijk Onderzoek ?.  相似文献   

19.
Let G be a compact, connected Lie group endowed with a bi-invariant Riemannian metric. Let t be the heat kernel on G; that is, t is the fundamental solution to the heat equation on the group determined by the Laplace–Beltrami operator. Recent work of Gross (1993) and Hijab (1994) has led to the study of a new family of functions on G. These functions, obtained from t and its derivatives, are the compact group analogs of the classical Hermite polynomials on . Previous work of this author has established that these Hermite functions approach the classical Hermite polynomials on in the limit of small t, where the Hermite functions are viewed as functions on via composition with the exponential map. The present work extends these results by showing that these Hermite functions can be expanded in an asymptotic series in powers of . For symmetrized derivatives, it is shown that the terms with fractional powers of t vanish. Additionally, the asymptotic series for Hermite functions associated to powers of the Laplacian are computed explicitly. Remarkably, these asymptotic series terminate, yielding a polynomial in t.  相似文献   

20.
Let {f_n} be a sequence of functions meromorphic in a domain D, let {h_n} be a sequence of holomorphic functions in D, such that that h(z)→h(z), where h.(z)→0 is holomorphic in D, and let k be a positive integer. If for each n∈N~+, f_n(z)≠0 and f_n~(k)(z)-h_n(z) has at most k distinct zeros(ignoring multiplicity) in D, then {f_n} is normal in D.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号