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221.
The initial boundary value problem for linear elastodynamic system for viscoporous materials is considered. Exponential decay of solutions via the linear boundary feedback is established. Existence of solutions is obtained through the method of c0‐semigroups. Exponential stabilization is derived via a proper collection of ideas of observability inequality, energy identity and c0‐semigroup of contractions. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
222.
We prove that the class of finite dimensional selfinjective algebras over a field which admit Galois coverings by the repetitive
algebras of the quasitilted algebras, with Galois groups generated by compositions of the Nakayama automorphisms with strictly
positive automorphisms, is invariant under stable and derived equivalences.
Dedicated to Claus Michael Ringel on the occasion of his sixtieth birthday 相似文献
223.
The paper is concerned with the problem of reconstruction of acoustic or electromagnetic field from inexact data given on an open part of the boundary of a given domain. A regularization concept is presented for the moment problem that is equivalent to a Cauchy problem for the Helmholtz equation. A method of regularization by projection with application of the Meyer wavelet subspaces is introduced and analyzed. The derived formula, describing the projection level in terms of the error bound of the inexact Cauchy data, allows us to prove the convergence and stability of the method. 相似文献
224.
Numerous laboratory experiments indicate that the use of a layer or a coating material attached to the conventional steel body reduce the magnitude of contact stress. Therefore in this paper we solve numerically the wheel–rail contact problem with friction and wear assuming the existence of a small elastic layer on the rail surface. Material properties of this layer are changing with its depth. The friction between the bodies is governed by Coulomb law. In contact zone Archard's law of wear is assumed. We take special features of this rolling contact problem and use so-called quasistatic approach to solve this contact problem. Finite element method is used as a discretization method. The numerical results including the distribution of normal stress along the contact boundary are provided and discussed. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
225.
Daniel Král’ Jan Kratochvíl Andrzej Proskurowski Heinz-Jürgen Voss 《Discrete Applied Mathematics》2006,154(4):660-672
A mixed hypergraph is a triple (V,C,D) where V is its vertex set and C and D are families of subsets of V, called C-edges and D-edges, respectively. For a proper coloring, we require that each C-edge contains two vertices with the same color and each D-edge contains two vertices with different colors. The feasible set of a mixed hypergraph is the set of all k's for which there exists a proper coloring using exactly k colors. A hypergraph is a hypertree if there exists a tree such that the edges of the hypergraph induce connected subgraphs of the tree.We prove that feasible sets of mixed hypertrees are gap-free, i.e., intervals of integers, and we show that this is not true for precolored mixed hypertrees. The problem to decide whether a mixed hypertree can be colored by k colors is NP-complete in general; we investigate complexity of various restrictions of this problem and we characterize their complexity in most of the cases. 相似文献
226.
Anna Ja?kiewicz Andrzej S. Nowak 《Journal of Mathematical Analysis and Applications》2006,316(2):495-509
We consider Markov control processes with Borel state space and Feller transition probabilities, satisfying some generalized geometric ergodicity conditions. We provide a new theorem on the existence of a solution to the average cost optimality equation. 相似文献
227.
In the article, we study the structure of Galois coverings of self-injective artin algebras with infinite cyclic Galois groups. In particular, we characterize all basic, connected, self-injective artin algebras having Galois coverings by the repetitive algebras of basic connected artin algebras and with the Galois groups generated by positive automorphisms of the repetitive algebras. 相似文献
228.
We start by introducing a Čech homology with compact supports which we then use in order to construct an infinite-dimensional
homology theory. Next we show that under appropriate conditions on the nonlinearity there exists a ground state solution for
a semilinear Schr?dinger equation with strongly indefinite linear part. To this solution there corresponds a nontrivial critical
group, defined in terms of the infinite-dimensional homology mentioned above. Finally, we employ this fact in order to construct
solutions of multibump type. Although our main purpose is to survey certain homological methods in critical point theory,
we also include some new results.
Dedicated to Felix Browder on the occasion of his 80th birthday 相似文献
229.
Andrzej Dabrowski 《Journal of Combinatorial Theory, Series A》1997,80(2):385-544
We give short elementary proof of some combinatorial result in the theory of automorphic pseudodifferential operators. 相似文献
230.