共查询到20条相似文献,搜索用时 31 毫秒
1.
Mustafa Kaya 《Applied mathematics and computation》2011,217(19):7669-7678
In this study, the new back controlled (BCSO) selection operator for genetic algorithm (GA) is presented. In the first stage, six existing operators and the BCSO were applied to the traveling salesman and space truss benchmark problems. An analysis of the results of the benchmark problems was made for each of the seven selection operators. In the second stage, the BCSO, the Roulette Wheel, dominant selection the hybrid II and operators were used to determine the fittest beam section has been used. In this stage, the cost of beam for a 18.3 m span developed by Mid-Atlantic States Pre-stressed Concrete Committee for Economic Fabrication and using a genetic algorithm the cost of a beam using BCSO were compared. It was determined that the beam produced using the proposed BCSO selection operator would be lower than those obtained with the existing selection operators. Also the determined beam cost is compares favourably with the average cost of a beam sold by the precast industry in the USA. 相似文献
2.
If Tφ is a hyponormal Toeplitz operator with polynomial symbol φ = ḡ + f (f, g ∈ H∞ (𝕋 )) such that g divides f, and if ψ := then where μ is the leading coefficient of ψ and 𝒵(ψ) denotes the set of zeros of ψ. In this paper we present a necessary and sufficient condition for Tφ to be hyponormal when φ enjoys an extremal case in the above inequality, that is, equality holds in the above inequality. 相似文献
3.
Dang Hung Thang 《Stochastics An International Journal of Probability and Stochastic Processes》2016,88(6):927-945
In this paper, we study infinite products of independent random operators. Conditions for the existence a.s. and the convergence in mean of order p of such infinite products are established. 相似文献
4.
Tyuriemskih's Lethargy Theorem is generalized to provide a useful tool for establishing when a sequence of (not necessarily) linear operators that converges point wise to the identity operator actually converges arbitrarily slowly. Then this generalization is used to answer affirmatively a 2010 conjecture of ours as well as establishing that all of the classical operators of Bernstein, Hermite-Fejer, Landau, Fejer, and Jackson converge arbitrarily slowly to the identity operator (and not just almost arbitrarily slowly as we established in 2010). 相似文献
5.
In this paper we study an application of nonlinear B‐bounded semigroups introduced in a previous paper. The application is similar to the particle transport problem which led to B‐bounded linear semigroups. We deal with a nonlinear particle transport problem, which can be solved by using B‐bounded nonlinear semigroups. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
6.
C-半群的Lumer-Phillips定理与C-Hermitian算子 总被引:1,自引:0,他引:1
本文给出了稠定闭算子A(或A的扩张)生成压缩C-半群的充分条件,且在C是等距算子时,证明了该条件是必要的,推广了Lumer-Phillips定理.并用结果刻划了等距C-群的生成元. 相似文献
7.
In this paper we prove subelliptic estimates for operators of the form Δx + λ2 (x)S in ?N = ? × ?, where the operator S is an elliptic integro - differential operator in ?N and λ is a nonnegative Lipschitz continuous function. 相似文献
8.
Gustavo Fernández André Arbex Hallack 《Journal of Mathematical Analysis and Applications》2005,309(1):52-55
In this paper we correct a proof by Aron and Markose in [R. Aron, D. Markose, On universal functions, J. Korean Math. Soc. 41 (2004) 65-76] for the hypercyclicity of the operator given by , in the case b≠0. 相似文献
9.
Daniel Carando Verónica Dimant Santiago Muro 《Journal of Mathematical Analysis and Applications》2007,336(2):1324-1340
A result of Godefroy and Shapiro states that the convolution operators on the space of entire functions on Cn, which are not multiples of identity, are hypercyclic. Analogues of this result have appeared for some spaces of holomorphic functions on a Banach space. In this work, we define the space holomorphic functions associated to a sequence of spaces of polynomials and determine conditions on this sequence that assure hypercyclicity of convolution operators. Some known results come out as particular cases of this setting. We also consider holomorphic functions associated to minimal ideals of polynomials and to polynomials of the Schatten-von Neumann class. 相似文献
10.
Ioan Gavrea 《Journal of Mathematical Analysis and Applications》2010,372(2):366-368
In this note we study the limit behavior of the iterates of a large class of positive linear operators preserving the affine functions and, as a byproduct of our result, we obtain the limit of the iterates of Meyer-König and Zeller operators. 相似文献
11.
Jesús de la Cal Javier Cárcamo 《Journal of Mathematical Analysis and Applications》2007,334(2):1106-1115
As a consequence of Jensen's inequality, centered operators of probabilistic type (also called Bernstein-type operators) approximate convex functions from above. Starting from this fact, we consider several pairs of classical operators and determine, in each case, which one is better to approximate convex functions. In almost all the discussed examples, the conclusion follows from a simple argument concerning composition of operators. However, when comparing Szász-Mirakyan operators with Bernstein operators over the positive semi-axis, the result is derived from the convex ordering of the involved probability distributions. Analogous results for non-centered operators are also considered. 相似文献
12.
A.S. Mohamed 《Applicable analysis》2013,92(3-4):179-184
In this paper, we study conditions under which Schrodinger type operators with a matrix potential is separated and Schrodinger equation has a unique solution in the weighted space L2,k(Rn)l, where l is any natural number and k ε C1(Rn) is a positive function 相似文献
13.
《Quaestiones Mathematicae》2013,36(3):399-410
Abstract An old result of J.S. Cohen states that each p* -summing operator on a L p -space has a p* -summing dual. Also, another old result of S. Kwapień states that each p* -summing operator on a Banach space X has a p* -summing dual if and only if X is isomorphic to a quotient of some L p (µ). In this paper we prove some multilinear and polynomial variants of these results. 相似文献
14.
Stanislav Shkarin 《Journal of Mathematical Analysis and Applications》2008,348(1):193-210
We prove that under certain topological conditions on the set of universal elements of a continuous map T acting on a topological space X, that the direct sum T⊕Mg is universal, where Mg is multiplication by a generating element of a compact topological group. We use this result to characterize R+-supercyclic operators and to show that whenever T is a supercyclic operator and z1,…,zn are pairwise different non-zero complex numbers, then the operator z1T⊕?⊕znT is cyclic. The latter answers affirmatively a question of Bayart and Matheron. 相似文献
15.
We consider a boundary value problem
where is a maximal monotone operator in and E is a multivalued operator in 2 with non decre asing resolvent. We introduce a condition on E which insures that the operator inL
1 (0,1) associated to this problem has non decreasing resolvent, and caracterise the subsolutions of the problem. We give different examples of operatorsE satisfying this condition. 相似文献
16.
J. C. Yao 《Journal of Optimization Theory and Applications》1994,83(2):391-403
In this paper, we first employ the 1961 celebrated Fan lemma to derive a very general existence result for multi-valued variational inequalities involving multi-valued K-pseudomonotone operators. It will be seen that this result improves and unifies existence results of variational inequalities for monotone operators. Next, we establish some uniqueness results for multi-valued variational inequalities by introducing the concepts of strict, , and strong K-pseudomonotonicity of multi-valued operators, respectively. These uniqueness results appear to be new even if the underlying space is finite-dimensional.This work was partially supported by the National Science Council Grant NSC 82-0208-M-110-023. The author would like to express his sincere thanks to the referees for their valuable comments and suggestions that improved this paper substantially. 相似文献
17.
Given a bounded selfadjoint operator a in a Hilbert space , the aim of this paper is to study the orbit of a, i.e., the set of operators which are congruent to a. We establish some necessary and sufficient conditions for an operator to be in the orbit of a. Also, the orbit of a selfadjoint operator with closed range is provided with a structure of differential manifold.
相似文献
18.
In Sung Hwang Woo Young Lee 《Transactions of the American Mathematical Society》2002,354(6):2461-2474
In this paper we establish a tractable and explicit criterion for the hyponormality of arbitrary trigonometric Toeplitz operators, i.e., Toeplitz operators with trigonometric polynomial symbols . Our criterion involves the zeros of an analytic polynomial induced by the Fourier coefficients of . Moreover the rank of the selfcommutator of is computed from the number of zeros of in the open unit disk and in counting multiplicity.
19.
Xuanhao Ding 《Journal of Mathematical Analysis and Applications》2008,337(1):726-738
In this paper we completely characterize when the product of a Hankel operator and a Toeplitz operator on the Hardy space is a finite rank perturbation of a Hankel operator, and when the commutator of a Hankel operator and a Toeplitz operators has finite rank. 相似文献
20.
Our main technical tool is a principally new property of compact narrow operators which works for a domain space without an absolutely continuous norm. It is proved that for every Köthe F-space X and for every locally convex F-space Y the sum T1+T2 of a narrow operator T1:X→Y and a compact narrow operator T2:X→Y is a narrow operator. This gives a positive answers to questions asked by M. Popov and B. Randrianantoanina [6, Problems 5.6 and 11.63]. 相似文献