Now showing items 184-203 of 244

    • Perfect (super) Edge-Magic Crowns 

      López Masip, Susana-Clara; Muntaner Batle, F. A.; Prabu, M. (Springer, 2017)
      A graph G is called edge-magic if there is a bijective function f from the set of vertices and edges to the set {1,2, ,|V(G)|+|E(G)|} such that the sum f(x)+f(xy)+f(y) for any xy in E(G) is constant. Such a function is ...
    • Period annulus of the harmonic oscillator with zero cyclicity under perturbations with a homogeneous polynomial field 

      García, I. A. (Isaac A.); Maza Sabido, Susana (Bolyai Institute. University of SzegedHungarian Academy of Sciences, 2019-01-14)
      In this work we prove, using averaging theory at any order in the small perturbation parameter, that the period annulus of the harmonic oscillator has cyclicity zero (no limit cycles bifurcate) when it is perturbed by any ...
    • Periodic orbits in Hyperchaotic Chen systems 

      Maza Sabido, Susana (Texas State University, 2015)
      In this work, we show a zero-Hopf bifurcation in a Hyperchaotic Chen system. Using averaging theory, we prove the existence of two periodic orbits bifurcating from the zero-Hopf equilibria located at the origin of ...
    • Periodic solutions for nonlinear differential systems: the second order bifurcation function 

      Buica, Adriana; Giné, Jaume; Llibre, Jaume (Nicolaus Copernicus University in Torun, Juliusz Schauder Centre for Nonlinear Studies, 2014)
      We are concerned here with the classical problem of Poincaré of persistence of periodic solutions under small perturbations. The main contribution of this work is to give the expression of the second order bifurcation ...
    • Polynomial and rational first integrals for planar homogeneous polynomial differential systems 

      Giné, Jaume; Grau Montaña, Maite; Llibre, Jaume (Universitat Autònoma de Barcelona, 2014)
      In this paper we find necessary and suficient conditions in order that a planar homogeneous polynomial differential system has a polynomial or rational first integral. We apply these conditions to linear and quadratic ...
    • Polynomial and rational first integrals for planar quasi-homogeneous polynomial differential systems 

      Giné, Jaume; Grau Montaña, Maite; Llibre, Jaume (American Institute of Mathematical Sciences, 2013-10)
      In this paper we find necessary and sufficient conditions in order that a planar quasi-homogeneous polynomial differential system has a polynomial or a rational first integral. We also prove that any planar quasi-homogeneous ...
    • Population Dynamics P system (PDP) models: a standarized protocol for describing and applying novel bio-inspires computing tools 

      Colomer, M. Àngels (Maria Àngels); Margalida, Antoni; Pérez Jiménez, Mario de Jesús (Public Library of Science (PLoS), 2013)
      Today, the volume of data and knowledge of processes necessitates more complex models that integrate all available information. This handicap has been solved thanks to the technological advances in both software and hardware. ...
    • Properties of mixed Moore graphs of directed degree one 

      López Lorenzo, Ignacio; Pujolàs Boix, Jordi (Elsevier, 2015-04-01)
      Mixed graphs of order n such that for any pair of vertices there is a unique trail of length at most k between them are known as mixed Moore graphs. These extremal graphs may only exist for diameter k = 2 and certain ...
    • Rainbow eulerian multidigraphs and the product of cycles 

      López Masip, Susana-Clara; Muntaner Batle, F. A. (DMTCS, 2016)
      An arc colored eulerian multidigraph with $l$ colors is rainbow eulerian if there is an eulerian circuit in which a sequence of $l$ colors repeats. The digraph product that refers the title was introduced by Figueroa-Centeno ...
    • Rendimiento matemático en contextos bilingües: análisis de la incidencia de algunas variables del contexto socio-educativo 

      Pifarré Turmo, Manoli; Sanuy Burgués, Jaume; Huguet, Àngel; Vendrell Serés, Mª Concepció (Universidad de Murcia. Servicio de PublicacionesAsociacion Interuniversitaria de Investigacion Pedagógica (AIDIPE), 2003)
      El trabajo que se presenta en este artículo se sitúa en el contexto bilingüe de la provincia de Lleida en la que coexisten dos lenguas en contacto, el catalán y el castellano, si bien existe un predominio de uso familiar ...
    • Repairing an aggregation-based smart metering system 

      Garra Oronich, Ricard; Leibenger, Dominik; Miret, Josep M. (Josep Maria); Sebé Feixas, Francesc (Springer Berlin Heidelberg, 2019-04-05)
      Smart meters inform the electricity suppliers about the consumption of their clients in short intervals. Fine-grained electricity consumption information is highly sensitive as it has been proven to permit to infer people's ...
    • Reversible nilpotent centers with cubic homogeneous nonlinearities 

      Dukaric, Masa; Giné, Jaume; Llibre, Jaume (Elsevier, 2016)
      We provide 13 non--topological equivalent classes of global phase portraits in the Poincaré disk of reversible cubic homogeneous systems with a nilpotent center at origin, which complete the classification of the phase ...
    • Review of mathematical models for sow herd management 

      Pla Aragonés, Lluís Miquel (Elsevier, 2007)
      This paper is a survey of the different sow models described in literature, which made use of different mathematical methodologies, and were intended for sow herd management. Models were discussed under a wide classification, ...
    • Searching for large multi-loop networks 

      Feria Purón, Ramiro; Pérez Rosés, Hebert; Ryan, Joe (Elsevier, 2014)
      We describe and implement a computer-based method to find large multi-loop graphs with given degree and diameter. For some values of degree and diame- ter, our algorithm produces the largest known circulant graphs. We ...
    • Secure many-to-one communications in wireless sensor networks 

      Viejo Galicia, Alexandre; Domingo i Ferrer, Josep; Sebé Feixas, Francesc; Castellà Roca, Jordi (Molecular Diversity Preservation International (MDPI), 2009)
      Wireless Sensor Networks (WSN) are formed by nodes with limited computational and power resources. WSNs are finding an increasing number of applications, both civilian and military, most of which require security for the ...
    • Securing Databases by using Diagonal-based Order Preserving Symmetric Encryption 

      Martínez Rodríguez, Santi; Miret, Josep M. (Josep Maria); Valls Marsal, Magda; Tomàs, Rosana (Natural Sciences Publishing, 2014)
      The amount of information stored in databases is constantly increasing. Databases contain multiple records, each of them divided in several data fields. And some of these fields may contain sensitive information, so there ...
    • Sequence Mixed Graphs 

      Dalfó, Cristina; Fiol, Miguel Angel; López Lorenzo, Ignacio (Elsevier, 2017)
      A mixed graph can be seen as a type of digraph containing some edges (or two opposite arcs). Here we introduce the concept of sequence mixed graphs, which is a generalization of both sequence graphs and iterated line ...
    • Sex-related differences in body condition and serum biochemical parameters in red deer (Cervus elaphus) naturally infected with Mycobacterium bovis 

      López Olvera, J. R.; Fernández de Mera, I. G.; Vidal, D.; Vicente, J.; Fierro, Y.; Gortázar, C.; Serrano Ferrón, Emmanuel (Elsevier, 2013)
      Although Mycobacterium bovis infection is commonly reported in red deer (Cervus elaphus), potential differences in the effects of infection on male and female animals in terms of body condition and clinical biochemistry ...
    • Small cutsets in arc-transitive digraphs of prime degree 

      López Masip, Susana-Clara (Elsevier, 2013)
      We give an upper bound for the size of non-trivial sets that have small boundary in a family of arc-transitive digraphs. We state the exact size for these sets in case of prime degree. We also give a lower bound for the ...
    • Space–time trends in Spanish bird electrocution rates from alternative information sources 

      Guil, Francisco; Colomer, M. Àngels (Maria Àngels); Moreno-Opo, Rubén; Margalida, Antoni (Elsevier, 2015)
      Interaction with man-made infrastructures is one of the main sources of non-natural bird mortality. Here, we use a long-term study (1980–2010) to analyse spatial and temporal patterns in avian electrocution in Spain, using ...