共查询到20条相似文献,搜索用时 15 毫秒
1.
In the present paper, we find that the Bemstein-Durrmeyer operators, besides their better applications in approximation theory and some other fields, are good tools in constructing translation network. With the help of the de la Vallee properties of the Bernstein-Durrmeyer operators a sequence of translation network operators is constructed and its degree of approximation is dealt. 相似文献
2.
In the present paper, we prove that the Bernstein-Kantorovič operators have the ability of preserving translation property
in both C and Lp norms.
Supported (in part) by the NSFC(10471130,10371024) of PRC and the Natural Science Foundation (Y604003) of Zhejiang Province. 相似文献
3.
In this paper,the technique of approximate partition of unity is used to construct a class of neural networks operators with sigmoidal functions.Using the modulus of continuity of function as a metric,... 相似文献
4.
We give a necessary and sufficient condition for the nilpotent operators to be similiar to irreducible operators, and give
an answer to D. A. Herrero Conjectures for nilpotent operators. 相似文献
5.
Werner Timmermann 《Acta Mathematica Hungarica》2005,107(1-2):149-160
Summary Structural results about elementary operators of length one, local elementary operators and injectivity preserving maps are proved. These are generalizations of results concerning algebras of bounded operators on Banach spaces to algebras of unbounded operators on Hilbert spaces. 相似文献
6.
M. Yahdi 《Proceedings of the American Mathematical Society》2006,134(9):2613-2620
The aim of this work is to study operators naturally connected to Ergodic operators in infinite-dimensional Banach spaces, such as Uniform-Ergodic, Cesaro-bounded and Power-bounded operators, as well as stable and superstable operators. In particular, super-Ergodic operators are introduced and shown to be strictly between Ergodic and Uniform-Ergodic operators, and that any power bounded operator is super-Ergodic in a superreflexive space. New relationships between these operators are shown, others are proven to be optimal or can be ameliorated according to structural properties of the Banach space, such as the superreflexivity or with unconditional basis.
7.
Normal operators similar to irreducible operators 总被引:1,自引:0,他引:1
A complete characterization of normal operators which are similar to irreducible operators and some related results are given. 相似文献
8.
本给出了一娄具有非负核函数的积分算子,并得到了该算子为拟零算子的充必要条件,该算子包括了重要的Hardy算子。 相似文献
9.
We study the action of translation operators on wavelet subspaces. This action gives rise to an equivalence relation on the
set of all wavelets. We show by explicit construction that each of the associated equivalence classes is non-empty. 相似文献
10.
In this paper, a family of interpolation neural network operators are introduced. Here, ramp functions as well as sigmoidal functions generated by central B-splines are considered as activation functions. The interpolation properties of these operators are proved, together with a uniform approximation theorem with order, for continuous functions defined on bounded intervals. The relations with the theory of neural networks and with the theory of the generalized sampling operators are discussed. 相似文献
11.
Kenneth R Davidson 《Journal of Functional Analysis》1977,24(3):291-302
We prove that an operator on H2 of the disc commutes modulo the compacts with all analytic Toeplitz operators if and only if it is a compact perturbation of a Toeplitz operator with symbol in H∞ + C. Consequently, the essential commutant of the whole Toeplitz algebra is the algebra of Toeplitz operators with symbol in QC. The image in the Calkin algebra of the Toeplitz operators with symbol in H∞ + C is a maximal abelian algebra. These results lead to a characterization of automorphisms of the algebra of compact perturbations of the analytic Toeplitz operators. 相似文献
12.
Oswald Wyler 《Annali di Matematica Pura ed Applicata》1964,66(1):251-263
Summary Generailzed Green's functions are kernels of integral operators with certain properties. Solution operators with these properties
are calledGreen's operators. Necessary and sufficient conditions for the existence of Green's operators are given for the general case, and for operators
on Banach spaces.
This work has been supported by Sandia Corporation, a prime contractor to the U. S. Atomic Energy Commission. 相似文献
13.
Elena Cordero Kasso A. Okoudjou 《Journal of Mathematical Analysis and Applications》2007,325(2):1103-1116
In this paper we introduce a notion of multilinear localization operators. By reinterpreting these operators as multilinear Kohn-Nirenberg pseudodifferential operators, we give sufficient conditions for their boundedness on products of modulation spaces. Moreover, we prove that these conditions are also necessary for the boundedness of the operators. Finally, as application, we construct various examples of bounded multilinear pseudodifferential operators. 相似文献
14.
In this paper, we obtain the continuity for some multilinear operators related to certain non-convolution operators on the
Triebel-Lizorkin space. The operators include Littlewood-Paley operator and Marcinkiewicz operator. 相似文献
15.
Zhirayr Avetisyan Alexey Karapetyants 《Mathematical Methods in the Applied Sciences》2023,46(1):811-829
We introduce and study in a general setting the concept of homogeneity of an operator and, in particular, the notion of homogeneity of an integral operator. In the latter case, homogeneous kernels of such operators are also studied. The concept of homogeneity is associated with transformations of a measure—measure dilations, which are most natural in the context of our general research scheme. For the study of integral operators, the notions of weak and strong homogeneity of the kernel are introduced. The weak case is proved to generate a homogeneous operator in the sense of our definition, while the stronger condition corresponds to the most relevant specific examples—classes of homogeneous integral operators on various metric spaces—and allows us to obtain an explicit general form for the kernels of such operators. The examples given in the article—various specific cases—illustrate general statements and results given in the paper and at the same time are of interest in their own way. 相似文献
16.
Nathan S. Feldman 《Proceedings of the American Mathematical Society》1999,127(4):1171-1181
An operator is essentially subnormal if its image in the Calkin algebra is subnormal. We shall characterize the essentially subnormal operators as those operators with an essentially normal extension. In fact, it is shown that an essentially subnormal operator has an extension of the form ``normal plus compact'.
The essential normal spectrum is defined and is used to characterize the essential isometries. It is shown that every essentially subnormal operator may be decomposed as the direct sum of a subnormal operator and some irreducible essentially subnormal operators. An essential version of Putnam's Inequality is proven for these operators. Also, it is shown that essential normality is a similarity invariant within the class of essentially subnormal operators. The class of essentially hyponormal operators is also briefly discussed and several examples of essentially subnormal operators are given.
17.
Kamil John 《Czechoslovak Mathematical Journal》1999,49(3):607-616
We suggest a method of renorming of spaces of operators which are suitably approximable by sequences of operators from a given class. Further we generalize J. Johnsons's construction of ideals of compact operators in the space of bounded operators and observe e.g. that under our renormings compact operators are u-ideals in the: space of 2-absolutely summing operators or in the space of operators factorable through a Hilbert space. 相似文献
18.
The proposed decision model, based on Analytic Network Process (ANP), has been developed in order to determine the dynamics
of the Global System for Mobile Communications (GSM) market. In accordance with the sequence of ANP, first of all, the problem
was structured and modeled. At the next step, a quantitative analysis was conducted with the customers in order to assess
the importance of the related factors and forecast the market shares of the Turkish mobile communication operators. The forecasted
market share values were compared with actual ones for the validation of the decision model. The assessed importance of the
factors in a valid model would be a potential competitive advantage for the mobile operators. 相似文献
19.
We give summability results for the eigenvalues of certain types of compact operators that are then applied to study integral operators. 相似文献
20.
《Topology and its Applications》1987,27(2):129-143
Closure operators in an (E, M)-category X are introduced as concrete endofunctors of the comma category whose objects are the elements of M. Various kinds of closure operators are studied. There is a Galois equivalence between the conglomerate of idempotent and weakly hereditary closure operators of X and the conglomerate of subclasses of M which are part of a factorization system. There is a one-to-one correspondence between the class of regular closure operators and the class of strongly epireflective subcategories of X. Every closure operators admits an idempotent hull and a weakly hereditary core.Various examples of additive closure operators in Top are given. For abelian categories standard closure operators are considered. It is shown that there is a one-to-one correspondence between the class of standard closure operators and the class of preradicals. Idempotent, weakly hereditary, standard closure operators correspond to idempotent radicals (= torsion theories). 相似文献