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Mostrando ítems 1-10 de 27
Artículo
Bifurcation from zero of a complete trajectory for non-autonomous logistic PDEs
(World Scientific Publishing, 2005-08)
In this paper we extend the well-known bifurcation theory for autonomous logistic equations to the non-autonomous equation ut − ∆u = λu − b(t)u 2 with b(t) ∈ [b0, B0], 0 < b0 < B0 < 2b0. In particular, we prove the ...
Capítulo de Libro
Ceremonias y prácticas de los indígenas americanos en los procesos bélicos
(Universidad Internacional de Andalucía, 2008)
Artículo
The symmetric action on secondary homotopy groups
(The Belgian Mathematical Society, 2008-11)
We show that the symmetric track groups Sym(n), which are extensions of the symmetric groups Sym(n) associated to the second Stiefel-Whitney class, act as crossed modules on the secondary homotopy groups of a pointed space.
Artículo
On the cycling operation in braid groups
(Elsevier, 2008-09-06)
The cycling operation is a special kind of conjugation that can be applied to elements in Artin’s braid groups, in order to reduce their length. It is a key ingredient of the usual solutions to the conjugacy problem in ...
Artículo
The 1-type of a Waldhausen K-theory spectrum
(Elsevier, 2007-12-01)
We give a small functorial algebraic model for the 2-stage Postnikov section of the K-theory spectrum of a Waldhausen category and use our presentation to describe the multiplicative structure with respect to biexact functors.
Artículo
A new controller for the inverted pendulum on a cart
(2008)
This paper presents a complete solution to the problem of swinging-up and stabilization of the inverted pendulum on a cart, with a single control law. The resulting law has two parts: first, an energy-shaping law is able ...
Artículo
Estimates for singular multiplicative character sums
(Duke University Press, 2005)
We give some estimates for multiplicative character sums on quasiprojective varieties over finite fields depending on the severity of the singularities of the variety at infinity. We also remove the hypothesis of ...
Artículo
Valuations in algebraic field extensions
(Elsevier, 2007-06-15)
Let K → L be an algebraic field extension and ν a valuation of K. The purpose of this paper is to describe the totality of extensions {ν′} of ν to L using a refined version of MacLane’s key polynomials. In the basic case ...
Artículo
Caprellid assemblages (Crustacea: Amphipoda) in shallow waters invaded by Caulerpa racemosa var. cylindracea from southeastern Spain
(BMC, 2009)
Growth of the invasive algae Caulerpa racemosa var. cylindracea in shallow habitats may inXuence the faunal assemblage composition. We studied its eVects on caprellid assemblages associated with shallow-water habitats ...
Artículo
Maltsiniotis's first conjecture for K1
(Duke University Press, 2008)
We show that K1(E) of an exact category E agrees with K1(DE) of the associated triangulated derivator DE. More generally we show that K1(W) of a Waldhausen category W with cylinders and a saturated class of weak equivalences ...