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  • Analysing spatial correlation of weeds and harvester ants in cereal fields using point processes 

    Comas Rodríguez, Carles; Royo-Esnal, Aritz; Recasens i Guinjuan, Jordi; Torra Farré, Joel (Springer Verlag, 2016)
    The interaction between the spatial distribution of weed richness and weed cover and the spatial location of harvester ant nets was investigated in cereal fields. The understanding of such interdependencies can be relevant ...
  • Estudio exploratorio de las respuestas de los estudiantes para maestro sobre el uso de la noción de medida en tareas matemáticas 

    Estrada Roca, M. Asunción; Moreno Moreno, Ma. del Mar; Huszar, Gabriel; Barbero Sola, Iván (Universitat Rovira i Virgili. Departament de Pedagogia, 2016)
    El siguiente informe de investigación aporta resultados sobre las respuestas a la prueba diagnóstica preparada ad hoc para la investigación que se está realizando con los estudiantes de primer curso del grado de Maestro ...
  • Analytic reducibility of nondegenerate centers: Cherkas systems 

    Giné, Jaume; Llibre, Jaume (Bolyai Institute, University of SzegedHungarian Academy of Sciences, 2016)
    In this paper we study the center problem for polynomial differential systems and we prove that any center of an analytic differential system is analytically reducible. x˙=y,y˙=P0(x)+P1(x)y+P2(x)y2, We also study the ...
  • Sequence Mixed Graphs 

    Dalfó, Cristina; Fiol, Miguel Angel; López Lorenzo, Ignacio (Elsevier, 2017-01-20)
    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 ...
  • Evaluación de la sustentabilidad del sistema agrícola de la Comunidad de Huapra (Perú) 

    Espinola, Jesús E.; Pla Aragonés, Lluís Miquel; Montañez, Eddy J.; Leyva, Jorge W.; Cáceres, Vladimir A. (Universidad de la Habana, 2017)
    This paper assesses the agricultural sustainability of the peasant community of Huapra, located in the Andes of Peru; this is a type of high land farming communities. The analysis has been made by applying the methodology ...
  • Integrability of Liénard systems with a weak saddle 

    Gasull i Embid, Armengol; Giné, Jaume (Springer International Publishing, 2017)
    We characterize the local analytic integrability of weak saddles for complex Li´enard systems, x˙ = y−F(x), y˙ = ax, 0 = a ∈ C, with F analytic at 0 and F(0) = F (0) = 0. We prove that they are locally integrable at the ...
  • A privacy-preserving reputation system with user rewards 

    Busom Figueres, Núria; Petrlic, R.; Sebé Feixas, Francesc; Sorge, C.; Valls Marsal, Magda (Elsevier, 2017)
    Reputation systems are useful to assess the trustworthiness of potential transaction partners, but also a potential threat to privacy since rating profiles reveal users’ preferences. Anonymous reputation systems resolve this ...
  • Clan information market games 

    El Obadi, Saadia; Miquel Fernández, Silvia (Springer US, 2016)
    We introduce a TU-game that describes a market where information is distributed among several agents and all these pieces of information are necessary to produce a good. This situation will be called clan information market. ...
  • Integrability conditions for Lotka–Volterra planar complex quintic systems 

    Giné, Jaume; Romanovski, Valery G. (Elsevier, 2010)
    In this paper we obtain necessary and sufficient integrability conditions at the origin for the Lotka–Volterra complex quintic systems which are linear systems perturbed by fifth degree homogeneous polynomials, i.e., we ...
  • The center problem for a 2:-3 resonant cubic Lotka–Volterra system 

    Dolićanin, Diana; Giné, Jaume; Oliveira, Regilene; Romanovski, Valery G. (Elsevier, 2013)
    In this paper we obtain conditions on the coefficients of a cubic Lotka–Volterra system of the form equation(1) x=x(2-a20x2-a11xy-a02y2), ẏ=y(-3+b20x2+b11xy+b02y2), which fulfillment yields the existence in a ...
  • 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 ...
  • The three-dimensional center problem for the zero-Hopf singularity 

    García, I. A. (Isaac A.); Valls, Claudia (American Institute of Mathematical Sciences, 2016-03-01)
    In this work we extend well-known techniques for solving the Poincar\'e-Lyapunov nondegenerate analytic center problem in the plane to the 3-dimensional center problem at the zero-Hopf singularity. Thus we characterize the ...
  • Cyclicity of a class of polynomial nilpotent center singularities 

    García, I. A. (Isaac A.); Shafer, Douglas S. (American Institute of Mathematical Sciences, 2016-04-01)
    In this work we extend techniques based on computational algebra for bounding the cyclicity of nondegenerate centers to nilpotent centers in a natural class of polynomial systems, those of the form $\dot x = y + P_{2m + ...
  • Center problem for systems with two monomial nonlinearities 

    Gasull i Embid, Armengol; Giné, Jaume; Torregrosa, Joan (American Institute of Mathematical Sciences, 2016)
    We study the center problem for planar systems with a linear center at the origin that in complex coordinates have a nonlinearity formed by the sum of two monomials. Our first result lists several centers inside this family. ...
  • Integrability of Lotka-Volterra planar complex cubic systems 

    Dukaric, Masa; Giné, Jaume (World Scientific, 2016)
    In this paper we study the Lotka-Volterra complex cubic systems. We obtain necessary conditions of integrability for these systems with some restriction on the parameters. The sufficiency is proved for all conditions, ...
  • Analytic integrability inside a family of degenerate centers 

    Algaba, Antonio; Checa, Isabel; García, Cristóbal; Giné, Jaume (Elsevier, 2016)
    In this paper we study the analytic integrability around the origin inside a family of degenerate centers or perturbations of them. For this family analytic integrability does not imply formal orbital equivalence to a ...
  • Centers and isochronous centers for generalized quintic systems 

    Giné, Jaume; Llibre, Jaume; Valls, Claudia (Elsevier, 2015)
    In this paper we classify the centers and the isochronous centers of certain polynomial differential systems in R2 of degree d≥5 odd that in complex notation are ż=(λ+i)z(zz̄)d−52(Az5+Bz4z̄+Cz3z̄2+Dz2z̄3+Ezz̄4+Fz̄5), ...
  • Optimizing the enzymatic elimination of clogging of a microfiltration membrane by Parellada grape cake 

    Conde Colom, Josep; Echavarría Vélez, Ana Paola; Ibarz Ribas, Alberto; Pagan i Gilabert, Jordi (Wiley, 2016)
    Clogging of the filtration membranes is one of the main problems in the process of obtaining grape must for white wine; therefore, clogging must be reduced to the maximum. The aim of this work was to find the optimal values ...
  • Centers for the Kukles homogeneous systems with odd degree 

    Giné, Jaume; Llibre, Jaume; Valls, Claudia (London Mathematical Society, 2015)
    For the polynomial differential system x˙ = −y, y˙ = x+Qn(x; y), where Qn(x; y) is a homogeneous polynomial of degree n there are the following two conjectures done in 1999. (1) Is it true that the previous system for ...
  • Integrability conditions of a resonant saddle perturbed with homogeneous quintic nonlinearities 

    Giné, Jaume; Valls, Claudia (Springer, 2015)
    In this work we complete the integrability conditions (i.e. conditions for the existence of a local analytic first integral) for a family of a resonant saddle perturbed with homogeneous quintic nonlinearities studied in a ...

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