Revistas académicas de la Universidad Católica del Norte
Not a member yet
1687 research outputs found
Sort by
Preserving fuzzy sg-closed sets Conservando conjuntos Fuzzy sg-cerrados
No full textIn this paper we consider new weak and stronger forms of fuzzy irresolute and fuzzy semi-closure via the concept Fsgclosed sets which we call Fap-irresolute maps, Fap-semi-closed maps and contra-fuzzy irresolute and we use it to obtain several results in the literature concerning the preservation of fuzzy sgclosed sets and to obtain also a characterization of fuzzy semiT1/2 spaces
Separation problem for sturm-liouville equation with operator coefficient
No full textLet H be a separable Hilbert Space. Denote by H1 = L2(a,b; H) the set of function defned on the interval a < c < b (¾¥ a < c < b £ ¥)whose values belong to H strongly measurable [12] and satisfying the conditionZ b a ||f(x)||2 Hdx < ? If the inner product of function ¦(c) and g(c) belonging to H1 is defined by (f, g)1 = Z b a (f(x), g(x))Hdx then H1 forms a separable Hilbert space. We study separation problem for the operator formed by ¾ y"+ Q (c) y Sturm-Liouville differential expression in L2(¾ ¥, ¥; H) space has been proved where Q (c) in an operator which transforms at H in value of c,,self-adjoint, lower bounded and its inverse is complete continous
Schottky uniformizations and riemann matrices of maximal symmetric Riemann surfaces of genus 5
No full textIn this note we consider pairs (S, ? ), where S is a closed Riemann surface of genus five and ? : S ? S is some anticonformal involution with fixed points so that K(S, ? ) = {h ? Aut±(S) : h? = ?h} has the maximal order 96 and S/? is orientable. We observe that there are exactly two topologically different choices for ? . They give non-isomorphic groups K(S, ? ), each one acting topologically rigid on the respective surface S. These two cases give then two (connect) real algebraic sets of real dimension one in the moduli space of genus 5. In this note we describe these components by classical Schottky groups and with the help of these uniformizations we compute their Riemann matrices
Theorémes de Zilber-Eilemberg et de Brown en homologie ??
No full textNotion of acyclic models are introduced in Eleinberg-Maclane [4]. In [5] and [3], this theory is used as auxiliary tools to solve extension problems of morphisms of chains complexes and homotopy between those morphisms.So in the first section of this work, we will adapt the notion of acyclic models in the category of Banach chain differential complexes Ch?(Ban). In the second section, we recall the functor of real ??-singular homology (cf. [8]) on which we apply theorems proved in the first section. In particular, we prove an analogous of Zilber-Eilenberg theorem [5] in real ??-singular homology. In last section, we prove an analogous of Brown theorem in real ??-singular homology. As consequence of this theorem we show that the real ??-singular homology depends only on the fundamental group and we establish some exact sequences
Parabolic perturbation in the family z ?1 + 1=wz?
No full textConsider the family of rational mapsFd = {z? fw(z) =1+ : w ? C\{0}} (d ? N, d ? 2)and the hyperbolic component A? = {w : fw has an attracting fixed point}. We prove that if w? ? ?A? is a parabolic parameter with corresponding multiplier a primitive q-th root of unity, q ? 2; then there exists a hyperbolic component Wq; attached to A? at the point w?; which contains w-values for which fw has an attracting periodic cycle of period q
On structure and commutativity of near-rings
No full textThe aim of this paper is to generalize the results in [1] and [13]. Here, we are interested in two problems concerning certain classes of near rings satisfying one of the following polynomials identities :(?) For each x; y in a near-ring N, there exist positive integers t = (x; y) ? 1 and s = s (x; y) > 1 such that xy = ±ysxt.(??) For each x; y in a near-ring N, there exist positive integers t = t (x; y) ? 1 and s = s (x; y) > 1 such that xy = ±xtys
Edge fixed monophonic number of a graph
No full textFor an edge xy in a connected graph G of order p ≥ 3, a set SCV(G)is an xy-monophonic set of G if each vertex v Є V(G) lies on an x-u monophonic path or a y-u monophonic path for some element u in S. The minimum cardinality of an xy- monophonic set of G is defined as the xy-monophonic number of G, denoted by mxy (G). An xy-monophonic set of cardinality mxy (G) is called a mxy -set of G. We determine bounds for it and find the same for special classes of graphs. It is shown that for any three positive integers r, d and n ≥ 2 with 2 ≤ r ≤ d, there exists a connected graph G with monophonic radius r, monophonic diameter d and mxy (G) = n for some edge xy in G
On some generalized geometric difference sequence spaces
No full textIn this paper we introduce the generalized geometric difference sequence spaces and to prove that these are Banach spaces. Then we prove some inclusion properties. Also we compute their dual spaces.
 
Positive periodic solutions for neutral functional differential systems
No full textWe study the existence of positive periodic solutions of a system of neutral differential equations. In the process we construct two map- pings in which one is a contraction and the other compact. A Krasnoselskii's fixed point theorem is then used in the analysis