Scielo RSS <![CDATA[Proyecciones (Antofagasta)]]> http://www.scielo.cl/rss.php?pid=0716-091720100003&lang=en vol. 29 num. 3 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<b>ON THE DISTRIBUTIONS OF THE DENSITIES INVOLVING NON-ZERO ZEROS OF BESSEL AND LEGENDRE FUNCTIONS AND THEIR INFINITE DIVISIBILITY</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300001&lng=en&nrm=iso&tlng=en In the present paper, we introduce the probability density functions involving non-zero zeros of the Bessel and Legendre functions. Then, we evaluate the distributions of the characteristic functions defined by these probability density functions and again obtain their related functions and polynomials. Finally, we prove the infinite divisibility of these probability density functions. <![CDATA[<b>A NEW DEFINITION OF S* CLOSEDNESS IN L-"TOPOLOGICAL SPACES</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300002&lng=en&nrm=iso&tlng=en In this paper, a new notion of S* closedness in L-topological Spaces is introduced by means of semi-open L-"sets and their inequality where L is a complete DeMorgan algebra.This new definition doesn´ t rely on the structure of basic lattice L. It can be characterized by means of semi-open L-"sets and their inequality . When L is completely distributive DeMorgan algebra, its many characterizations are presented. <![CDATA[<b>PARTIAL ORDERS IN REGULAR SEMIGROUPS</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300003&lng=en&nrm=iso&tlng=en First we have obtained equivalent conditions for a regular semigroup and is equivalent to N = N1 It is observed that every regular semigroup is weakly separative and C ? S and on a completely regular semigroup S ? N and S is partial order . It is also obtained that a band (S, .) is normal iff C = N . It is also observed that on a completely regular semigroup (S, .), C = S = N iff (S, .) is locally inverse semigroup and the restriction of C to E(S) is the usual partial order on E(S). Finally it is obtained that, if (S, .) is a normal band of groups then C = S = N . <![CDATA[<b>POLYNOMIAL SETS GENERATED BY e<sup>t</sup></b><b>f</b><b>(xt)</b><b>?</b><b>(yt)</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300004&lng=en&nrm=iso&tlng=en The present paper deals with two variables polynomial sets generated by functions of the form e tf(xt)?(yt). Its special case analogous to Laguerre polynomials have been discussed. <![CDATA[<b>GENERALIZED ULAM-HYERS STABILITIES OF QUARTIC DERIVATIONS ON BANACH ALGEBRAS</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300005&lng=en&nrm=iso&tlng=en Let A , B be two rings. A mapping δ : A → B is called quartic derivation, if δ is a quartic function satisfies δ(ab) = a4δ(b) + δ(a)b4 for all a, b ∈ A. The main purpose of this paper to prove the generalized Hyers-Ulam-Rassias stability of the quartic derivations on Banach algebras. <![CDATA[<b>ALPHA-SKEW-NORMAL DISTRIBUTION </b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300006&lng=en&nrm=iso&tlng=en The main object of this paper is to introduce an alternative form of generate asymmetry in the normal distribution that allows to fit unimodal and bimodal data sets. Basic properties of this new distribution, such as stochastic representation, moments, maximum likelihood and the singularity of the Fisher information matrix are studied. The methodology developed is illustrated with a real application. <![CDATA[<b>BIFURCATION OF THE ESSENTIAL DYNAMICS OF LORENZ MAPS ON THE REAL LINE AND THE BIFURCATION SCENARIO FOR LORENZ LIKE FLOWS</b>: <b>THE CONTRACTING CASE</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300007&lng=en&nrm=iso&tlng=en In this article we provide, by using kneading sequences, the combinatorial bifurcation diagram associated to a typical two parameter family of contracting Lorenz maps on the real line. We apply these results to two parameter families of geometric Lorenz-like flows. <![CDATA[<b>FINITE TOPOLOGIES AND DIGRAPHS</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-09172010000300008&lng=en&nrm=iso&tlng=en In this paper we study the relation between finite topologies and digraphs. We associate a digraph to a topology by means of the “specialization” relation between points in the topology. Reciprocally, we associate a topology to each digraph, taking the sets of vertices adjacent (in the digraph) to v, for all vertex v, as a subbasis of closed sets for the topology. We use these associations to examine the relation between a simple digraph and its homologous topology. We also extend this relation to the functions preserving the structure between these classes of objects.