72/2022 |
On the Hermitian metrics and complex structures of #nS³ x S³ Yuri Bozhkov rp-2022-72.pdf |

2/2022 |
Tópicos de processos estocásticos Vicenzo Bonasorte Reis Pereira , Élcio Lebensztayn rp-2022-022022.pdf |

1/2022 |
Estimates for entropy numbers of multiplier operators of multiple series Sérgio A. Córdoba, Jéssica Milaré, Sérgio A. Tozoni The asymptotic behavior for entropy numbers of general Fourier multiplier operators of rp-2022-012022.pdf |

1/2020 |
Extending Multivariate-t Semiparametric Mixed Models for Longitudinal data with Censored Responses and Heavy Tails Thalita B. Mattos, Larissa A. Matos, Victor H. Lachos In this paper we extended the semiparametric mixed model for longitudinal censored data with rp-2020-01.pdf |

6/2019 |
ON ARCS AND PLANE CURVES Beatriz Motta, Fernando Torres We investigate complete plane arcs which arise from the set of rational points of certain non-Frobenius classical plane curves over finite fields. We also point out direct consequences on the Griesmer bound for some linear codes. rp-2019-06.pdf |

5/2019 |
ON THE CURVE Y n = Xℓ(Xm + 1) OVER FINITE FIELDS II Saeed Tafazolian, Fernando Torres Abstract. Let F be the finite field of order q2. In this paper we continue the study rp-2019-05.pdf |

4/2019 |
Explosion in a Growth Model with Cooperative Interaction on an Innite Graph Bruna de Oliveira Gonçalves, Marina Vachkovskaia In this paper we study explosion/non-explosion of a continuous time growth process with cooperative interaction on Z+. We consider symmetric neighborhood and dierent types of rate functions and prove that explosion occurs for exponential rates, but not for polynomial. We also present some simulations to illustrate the explosion rp-2019-04.pdf |

3/2019 |
A NEW SIMPLE PROOF FOR THE LUM-CHUA'S CONJECTURE Victoriano Carmona, Fernando Fernández-Sánchez, Douglas D. Novaes. In this paper, using the theory of inverse integrating factor, we provide a new simple proof for the Lum-Chua's conjecture, which says that a continuous planar piecewise linear differential system with two zones separated by a straight line has at most one limit cycle. In addition, we prove that if this limit cycle exists, then it is hyperbolic and its stability is characterized in terms of the parameters. To the best of our knowledge, the hyperbolicity of the limit cycle has not been pointed out before. rp-2019-03.pdf |

2/2019 |
Estimates for n-widths of sets of smooth functions on complex spheres Deimer J. J. Aleans, Sergio A. Tozoni In this work we investigate n-widths of multiplier operators defined for functions on a complex sphere and bounded from L^p into L^q. We study lower and upper estimates for the n-widths of Kolmogorov, linear, of Gelfand and of Bernstein, of such operators. As application we obtain, in particular, estimates for the Kolmogorov n-width of classes of Sobolev, of finitely differentiable, infinitely differentiable and analytic functions on a complex sphere, in L^q, which are order sharp in various important situations. rp-2019-02.pdf |

1/2019 |
Estudo de um Método Baseado em Autovalores Generalizados para o Subproblema de Região de Confiança Jean Carlos A. Medeiros , Sandra Augusta Santos The trust-region methods are iterative methods for numerically solving minimization problems, not only unconstrained but also constrained ones. They consist of defining a quadratic model for the objective function f from a current point x^k and establishing a closed ball centered on x^k and with radius Δ; this neighborhood around x^k is called trust region, because in this region we will trust that the model generates a good approximation for the objective function; then each iteration will have a subproblem of minimizing the model subject to the trust region, thereby generating a sequence of approximations to the solution of the problem, ie the objective function minimizer. Recently, Adachi et al.[1], based on Gander et al.[4], developed a method adressing the subproblem in a non-iterative way, solving only one generalized eigenvalue problem. This work investigates the usage of this strategy for solving low dimensional unconstrained minimization problems. The visual appeal provides an additional tool for exploring the geometric features of this approach. rp-2019-01.pdf |