首页期刊导航|Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales, Serie A. Matematicas
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Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales, Serie A. Matematicas
Real Academia de Ciencias Exactas, Fisicas y Naturales
Real Academia de Ciencias Exactas, Fisicas y Naturales
1578-7303
Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales, Serie A. Matematicas/Journal Revista de la Real Academia de Ciencias Exactas, Fisicas y Naturales, Serie A. Matematicas
查看更多>>摘要：We prove that Eberlein's theorem holds for the Mackey* topology in the dual X* of a Banach space. This improves a result of Howard. We prove, too, that in general the space X* endowed with the Mackey* topology is not angelic.
查看更多>>摘要：We characterize quasi-reflexive barrelled and complete locally convex Hausdorff spaces with a basis in terms of the properties of this basis. Moreover we prove that a complete, barrelled IcHs with a basis is quasi-reflexive of order one if and only if for every power bounded operator T, either T or T' is mean ergodic.
查看更多>>摘要：Let X be a completely regular (Tychonoff) space, and let C(X), U(X), and B_1(X) denote the sets of all real-valued functions on X that are continuous, have a closed graph, and of the first Baire class, respectively.We prove that U(X) = C(X) if and only if X is a P-space (i.e., every G_δ-subset of X is open) if and only if B_1 (X) = U(X). This extends a list of equivalences obtained earlier by Gillman and Henriksen, Onuchic, and Iseki. The first equivalence can be regarded as an unconditional closed graph theorem; it implies that if X is perfectly normal or first countable (e.g., metrizable), or locally compact, then there exist discontinuous functions on X with a closed graph. This complements earlier results by Dobos and Baggs on discontinuity of closed graph functions.
Eugenio Roanes-LozanoLuis M. LaitaAntonio HernandoEugenio Roanes-Macias...
P.19-40页
查看更多>>摘要：This article presents a survey of the authors' research on knowledge extraction and verification of Rule Based Expert Systems (RBES) using algebraic inference engines and based on Grobner bases theory. A shell, including a graphic user interface and inference engines for different logics (both classic and modal multi-valued) as well as in different computer algebra systems, is also presented here. The shell distinguishes three levels: at the lower level, we provide the computer algebra system code of the algebraic inference engines; at the intermediate level, the RBES developer has to detail the rules and integrity constraints of a certain RBES; and, finally, at the upper level, the final user deals with a simple GUI, where he can perform knowledge extraction or verify the RBES, after choosing the logic and inputing a consistent set of facts. We believe that this shell can be really useful for teaching and quick RBES design.
查看更多>>摘要：We reconsider bargaining models developed to determine fair and reasonable solution outcomes for bargaining problems. Based on these models we develop novel negotiation support methods that will be able to produce on demand recommendations during a negotiation process. We first briefly discuss Raiffa's solution of balanced increments and, based on that idea, propose another solution based on balanced concessions. The combined application of the bargaining process models associated with these solutions leads to a flexible negotiation support method. A risk sharing negotiation problem illustrates how to implement our negotiation support method in a negotiation case.
F. Javier GironElias MorenoGeorge CasellaM. L. Martinez...
P.57-67页
查看更多>>摘要：Casella et al. [2, (2009)] proved that, under very general conditions, for normal linear models the Bayes factor for a wide class of prior distributions, including the intrinsic priors, is consistent when the number of parameters does not grow with the sample size n. The special attention paid to the intrinsic priors is due to the fact that they are nonsubjective priors, and thus accessible priors for complex models.The case where the number of parameters of nested models grows as O (n~α) for α ≤ 1 was considered in Moreno et al. [13, (2010)], in which it was proved that the Bayes factor for intrinsic priors is consistent for the case where both models are of order O(n~α) for a < 1, and for a = 1 is consistent except for a small set of alternative models. The small set of models for which consistency does not hold was characterized in terms of a pseudo-distance between models.The goal of the present article is to extend the above results to the case where the linear models are nonnested. As the comparison of nonnested models calls for a method of encompassing, for proving consistency we use encompassing from below in this paper.
查看更多>>摘要：We show that which that for a Berwald structure, any Riemannian structure that is preserved by the Berwald connection leaves the indicatrix invariant under horizontal parallel transport. We also obtain the converse result: if (M, F) is a Finsler structure such that there exists a Riemannian structure that leaves invariant the indicatrix under parallel transport of the associated Levi-Civita connection, then the structure (M, F) is Berwald. As application, a necessary condition for pure Landsberg spaces is formulated. Using this criterion we provide an strategy to solve the existence or not of pure Landsberg surfaces.
Gabriel BartoliniAntonio F. CostaMilagros IzquierdoAna M. Porto...
P.81-86页
查看更多>>摘要：The moduli space M_g of compact Riemann surfaces of genus g has the structure of an orbifold and the set of singular points of such orbifold is the branch locus B_g. In this article we present some results related with the topology of B_g. We study the connectedness of B_g for g ≤ 8, the existence of isolated equisymmetric strata in the branch loci and finally we stablish the connectedness of the branch locus of the moduli space of Riemann surfaces considered as Klein surfaces. We just sketch the proof of some of the results; complete proofs will be published elsewhere.
查看更多>>摘要：A compact Riemann surface X of genus g > 1 is said to be a p-hyperelliptic if X admits a conformal involution ρ for which X/ρ has genus p. This notion is the particular case of so called cyclic (q, n)-gonal surface which is defined as the one admitting a conformal automorphism δ of order n such that X/δ has genus q. It is known that for g > Ap + 1, ρ is unique and so central in the automorphism group of X. We give necessary and sufficient conditions on p and g for the existence of a Riemann surface of genus g admitting commuting p-hyperelliptic involution ρ and (q, n)-gonal automorphism δ for some prime n and we study its group of automorphisms and the number of fixed points of δ. Furthermore, we deal with automorphism groups of Riemann surfaces admitting central automorphism with at most 8 fixed points. The condition on the small number of fixed points of such an automorphism is justified by the study of p-hyperelliptic surfaces.
查看更多>>摘要：Let X be a real Banach space, let A: D(A) is contained in X → X be an m-dissipative operator, let / a nonempty, bounded interval and let K: I → D(A) be a given multi-valued function. By using the concept of A-quasi-tangent set introduced by Carja, Necula, Vrabie [8] and [9] and using a tangency condition expressed in the terms of this concept, we establish a necessary and sufficient condition for C~0-viability referring to nonlinear evolution inclusions of the form u'(t) ∈ Au(t) + F(t,u(t)), where F is a multi-function defined on the graph of K. As an application, we deduce a comparison result for a class of fully nonlinear evolution inclusions driven by multi-valued perturbations of subdifferentials.
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