Seminar 2018.2
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Organized by Reinier Diaz Millan
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The seminars in this semester will be held in the Lecture Room of IME/UFG, unless otherwise stated. All interested are very welcome to attend.
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Title: An complexity analysis of gradient descent for multiobjective optimization
Speaker: Mauricio Silva Louzeiro (Ph.D. student-IME/UFG)
Abstract: An complexity analysis of gradient descent for multiobjective optimization is analyzed in this talk. In addition, the results of the paper "Fliege, J.; A. I. F. Vaz; L. N. Vicente. Complexity of gradient descent for multiobjective optimization. (2018) " will be discussed.
Data: 23/08/2018
Hora: 08:00 hrs
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Title: A partially inexact generalized alternating direction method of multipliers and its iteration-complexity analysis
Speaker: Vando A. Adona (Ph.D student-IME/UFG)
Abstract: In this talk we will present the complexity analysis of a version partially inexact of the alternating direction method of multipliers for computing approximate solution of a linearly constrained convex optimization problem. Some numerical tests
for the proposed method will also be illustrated.
Data: 30/08/2018
Hora: 08:00 hrs
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Title: A Wolfe line search algorithm for vector optimization
Speaker: Leandro da Fonseca Prudente (Professor-IME/UFG)
Abstract: In a recent paper, Lucambio Pérez and Prudente extended the Wolfe conditions for the vector-valued optimization. In this talk, we will present a line search algorithm for finding a step-size satisfying the strong Wolfe conditions in the vector optimization setting. Well definiteness and finite termination results will be presented. We will discuss practical aspects related to the algorithm and present some numerical experiments illustrating its applicability.
Data: 06/09/2018
Hora: 08:00 hrs
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Title:Non-linear conjugate gradients algorithm in Riemannian Manifolds
Speaker: Luís Roman Lucambio Perez (Prof. IME/UFG)
Abstract: We will present an example of Vector Optimization Problem on Riemannian Manifold,
which, besides to be potentially useful, fulfils all hypothesis for global convergence of the by us
proposed conjugate gradient methods with the vector extensions of the Fletcher—Reeves,
Conjugate Descent, Dai—Yuan, Polak—Ribiére—Polyak and Hestenes—Stiefel parameters.
Data: 13/09/2018
Hora: 08:00 hrs
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Title: On the spherical quasi-convexity of quadratic functions
Speaker: Orizon Pereira Ferreira (Prof. IME/UFG) (joint work with Sándor Z. Németh and Lianghai Xiao)
Abstract: This talk is about the spherical quasi-convexity of quadratic functions on
spherically convex sets. Several conditions characterizing the spherical
quasi-convexity of quadratic functions are presented. In particular,
conditions implying spherical quasi-convexity of quadratic functions on
the spherical positive orthant are given. Some examples are provided as
an application of the obtained results.
Data: 20/09/2018
Hora: 08:00 hrs
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Title: Inexact proximal point method for locally Lipschitz functions in multiobjective optimization
Speaker: Lucas Vidal de Meireles (Ph.D student-IME/UFG)
Abstract: In this talk is presented a notion of approximate Pareto solution, which was introduced by Loridan in 1984, a condition necessary for characterizing such solution is studying for multiobjective programming. Moreover, exploiting these solutions formulate an inexact proximal point method for multiobjective optimization. The main convergence result is applied to locally Lipschitz functions. Also is proved full convergence to a weak Pareto optimal when the multiobjective program is convex.
Data: 27/09/2018
Hora: 08:00 hrs
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Title:Steepest Descent Method for Multiobjective Optimization on Riemannian Manifolds.
Speaker: Mauricio Silva Louzeiro (Ph.D. student-IME/UFG)
Abstract: In this talk, the steepest descent method for multiobjective optimization on Riemannian manifolds will be studied. An asymptotic convergence analysis, as well as limits of complexity, will be presented.
Data: 4/10/2018
Hora: 08:00 hrs
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Title: Convergence rates for the multiobjective proximal point method
Speaker: Ray Victor Guimarães Serra (Ph.D. student-IME/UFG)
Abstract: In this talk, we will present some convergence rate results for the multiobjective proximal point method and some variants.
Data: 11/10/2018
Hora: 08:00 hrs
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Title:Inexact and accelerated proximal point algorithms
Speaker: Tiago da Costa Menezes (Ph.D. student-IME/UFG)
Abstract: In this talk will be presented the paper "SALZO, Saverio; VILLA, Silvia. Inexact and accelerated proximal point algorithms. Journal of Convex analysis, v. 19, n. 4, p. 1167-1192, 2012.".Our main objective will be to present inexact accelerated proximal point algorithms for minimizing a proper lower semicontinuous and convex function, under different types of errors in the evaluation of the proximity operator and the corresponding convergence rates for the objective function values.
Speaker: Tiago da Costa Menezes​
Data: 25/10/2018
Hora: 08:00 hrs
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Title: On the gradient sampling algorithm
Speaker: Paulo César da Silva Júnior (Ph.D. student-IME/UFG)
Abstract: In the seminar will presented some results of the paper "Burke, J.V., Lewis, A.S., Overton, M.L.: A robust gradient sampling algorithm for nonsmooth, nonconvex optimization. SIAM J. Optim. 15(3), 751–779 (2005)".
Data: 01/11/2018
Hora: 08:00 hrs
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Title: Inexact Newton method for solving constrained nonlinear equations
Speaker: Fabiana Rodrigues de Oliveira (Ph.D. student-IME/UFG)
Abstract: In this talk, we present a version of inexact Newton method for solving constrained nonlinear equations. Under local assumptions, we will discuss the convergence rates of a sequence generated by the method. Moreover, some special cases and numerical experiments are mentioned.
Data: 08/11/2018
Hora: 08:00 hrs
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Title: A method for constrained injective-overdetermined nonlinear systems
Speaker: Fabrícia Rodrigues de Oliveira (Ph.D. student-IME/UFG)
Abstract: In this talk, we will present a method for solving constrained injective-overdetermined nonlinear systems. Under a majorant condition, the local convergence of the proposed method as well as results on its rate will be established.
Data: 22/11/2018
Hora: 08:00 hrs
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Title: Subgradient Method with feasible inexact projections for constrained convex optimization
Speaker: Ademir Alves Aguiar (Ph.D. student-IME/UFG)
Abstract: In this talk, we will present a version of Subgradient Method with feasible inexact projections for constrained convex optimizatio and its convergence analysis with differents stepsizes.
Data: 29/12/2018
Hora: 08:00 hrs
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Title: A proximal point method for DC functions on Hadamard manifolds
Speaker: Pedro Bonfim de Asunção Filho
Abstract: In this talk will be presented the paper " Souza,J.C.O. , Oliveira,P.R.; A proximal point method for DC functions on Hadamard manifolds, Jornal of Global Optimization, 63(4), 797-810, 2015.". The objective are present an extension of proximal point algorithm for difference of two convex functions in the context of riemannian manifolds.
Data: 06/12/2018
Hora: 08:00 hrs
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Coordinator schedule:
Reinier Diaz Millan (2018/2)
Luis Roman (2019/1)
Leandro F. Prudente (2019/2)
Glaydston C. Bento (2020/1)
Jefferson D. G. Melo (2020/2)