Seminar August 7th of 2024

Seminar August 7th of 2024

Seminar in EDP and Applied Mathematics

August 7th , 2024 – 14h (Brazil)

Streaming: Youtube Channel | SEMINARIO DE EDP E MATEMATICA APLICADA 

Event

About Seminars

Our Online Seminar is one of the most important events in Brazil, it has been held since August 2020, every Wednesday at 2 pm, Brasília time, with a frequency of 14 days. Two 40-minute lectures are presented in each session. Our speakers are world-renowned mathematicians from Europe, the United States and South America.

Featured Talks & Speakers

Yue Wang

Department of Mathematics, FAU Erlangen-Nürnberg-Germany

14:00h – 14:40h

Random Batch Methods for Optimal Control of Networked 1D Hyperbolic Systems

 Optimal control for networks of hyperbolic systems is important in many
applications, such as gas networks, flexible multi-body systems, and
water networks. However, solving such optimal control problems can be
computationally demanding when the network is large or contains loops.
In this talk, we present new convergence results for the simulation and
optimal control of 1D hyperbolic systems by the Random Batch Method
(RBM). The RBM is a recently proposed randomized operator-splitting
technique inspired by the successes of stochastic algorithms in machine
learning [Shi Jin, Lei Li, Jian-Guo Liu, J. of Comp. Phys. , 2020]. The
results in this talk are the first extension of the analysis for
finite-dimensional optimal control problems in [Veldman, Zuazua, Numer.Math., 2022] to hyperbolic partial differential equations. A numerical example for a network with loops shows that the proposed method reduces the computational cost significantly.

Laurent Prouvée

Universidade Estadual do Rio de Janeiro UERJ-Brazil

14:50h – 15:30h

Local and global null controllability of a nonlinear
parabolic system with a multiplicative control in moving
domains

This presentation deals with the local and global null controllability of a nonlinear parabolic coupled system in a domain whose boundary moves in time by a control force with a multiplicative part acting on a prescribed subdomain. Our approach relies on an application of Liusternik’s inverse
mapping theorem that demands the proof of suitable Carleman estimate.

About Organization

Juan Limaco -UFF-Coordenador
Mauro Rincon – UFRJ – Brazil
Anna Doubova-U.Sevilla-Spain

Luz de Teresa-UNAM Mexico

Diego Souza – U Sevilla -Spain

Felipe Chaves-UFPB-Brazil

Roberto Capistrano – UFPE Brazil 
Sandra Malta – LNCC – Brazil
Marcelo Cavalcanti – UEM – Brazil;
Rui Almeida – UBI – Portugal
Roxana Lopez – UNMSM – Peru;
Mauricio Sepulveda – UdeC -Chile;

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Seminar July 24th of 2024

Seminar July 24th of 2024

Seminar in EDP and Applied Mathematics

July 24, 2024 – 14h (Brazil)

Streaming: Youtube Channel | SEMINARIO DE EDP E MATEMATICA APLICADA 

Event

About Seminars

Our Online Seminar is one of the most important events in Brazil, it has been held since August 2020, every Wednesday at 2 pm, Brasília time, with a frequency of 14 days. Two 40-minute lectures are presented in each session. Our speakers are world-renowned mathematicians from Europe, the United States and South America.

Featured Talks & Speakers

Praveen Agarwal

Anand International College of Engineering-India   Ajman University,-United Arab Emirates.

14:00h – 14:40h

Extended Caputo k- type fractional derivative operator

 Some fractional integral and derivative operators of any arbitrary order have gained considerable popularity and importance during the past few decades. The Caputo fractional derivative operator is one of the most popular of them which provides an improved formula for fractional derivatives. In this talk, we present some extensions of the k- hypergeometric functions and then develop the extended Caputo k- type fractional derivative operator by using two parameters k- Mittag-Le er function. We also discuss some properties like generating functions and Mellin transform of the new extended Caputo k- type fractional derivative operator.

 

Hannes Meinlschmidt

Department of Mathematics, FAU Erlangen-Nürnberg-Germany

14:50h – 15:30h

 Renormalized solutions for optimal control of the drift in Fokker-Planck equations

We consider a bilinear optimal control problem subject to a
Fokker-Planck equation, where the control acts as the temporal amplitude of a given spatial vector field in the first-order drift term. The
problem setup regarding the spatial vector field is going to be very
restrictive, so we cannot rely on the usual energy methods; this is
motivated by applications. We thus propose to work with a renormalized
concept of solutions here, which is however inherently nonlinear and
thus in principle not compatible with established optimal control
theory. It will be shown how to overcome these issues and how to
establish optimality conditions for the optimal control problem.

About Organization

Juan Limaco -UFF-Coordenador
Mauro Rincon – UFRJ – Brazil
Anna Doubova-U.Sevilla-Spain

Luz de Teresa-UNAM Mexico

Diego Souza – U Sevilla -Spain

Felipe Chaves-UFPB-Brazil

Roberto Capistrano – UFPE Brazil 
Sandra Malta – LNCC – Brazil
Marcelo Cavalcanti – UEM – Brazil;
Rui Almeida – UBI – Portugal
Roxana Lopez – UNMSM – Peru;
Mauricio Sepulveda – UdeC -Chile;

Our Partners

Access our channel!

A channel for students, professors, researchers and professionals who wish to deepen their knowledge in EDP and applied mathematics.

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Seminar July 10th of 2024

Seminar July 10th of 2024

Seminar in EDP and Applied Mathematics

July 10, 2024 – 14h (Brazil)

Streaming: Youtube Channel | SEMINARIO DE EDP E MATEMATICA APLICADA 

Event

About Seminars

Our Online Seminar is one of the most important events in Brazil, it has been held since August 2020, every Wednesday at 2 pm, Brasília time, with a frequency of 14 days. Two 40-minute lectures are presented in each session. Our speakers are world-renowned mathematicians from Europe, the United States and South America.

Featured Talks & Speakers

Alberto Domínguez Corella

Department of Mathematics, FAU Erlangen-Nürnberg-Germany

14:00h – 14:40h

A randon domain decomposition scheme for parabolic PDE constrained optimization problems

Probability theory has had a significant impact on various areas of mathematics, particularly in algorithms and
combinatorics. The use of randomness in algorithms dates back to the Monte Carlo methods [6, 7]. In subsequent
years, random algorithms gained strength in optimization, notably with the emergence of techniques such as
simulated annealing [5] and genetic algorithms [4], which were used in complex optimization problems. In
recent years, stochastic gradient descent has attracted attention in machine learning and artificial intelligence; its
development has been crucial in training large-scale models, specially machine learning algorithms, see [1, 2].
In this talk, we discuss a random domain decomposition scheme for parabolic optimal control problems,
inspired by mini-batch algorithms used in machine learning. This scheme is based on the papers [3, 8] The method
discretizes the parabolic equation using the explicit Euler scheme and replaces the full elliptic operator with a
randomly selected elliptic operator acting on a part of the domain at each step. This approach aims to reduce
computational time. We will demonstrate the convergence of the scheme, highlighting the trade-off between speed
and accuracy. Special attention is paid to optimal control problems with bang-bang minimizers.
Acknowledgements
The author has been funded by means of an Alexander von Humboldt scholarship.
References
[1] Léon Bottou. Large-scale machine learning with stochastic gradient descent. In Proceedings of COMPSTAT’2010, pages 177–186.
Physica-Verlag/Springer, Heidelberg, 2010.
[2] Léon Bottou, Frank E. Curtis, and Jorge Nocedal. Optimization methods for large-scale machine learning. SIAM Rev., 60(2):223–311,
2018. doi:10.1137/16M1080173.
[3] Monika Eisenmann and Tony Stillfjord. A randomized operator splitting scheme inspired by stochastic optimization methods. arXiv
preprint arXiv:2210.05375, 2022.
[4] John H. Holland. Adaptation in natural and artificial systems. University of Michigan Press, Ann Arbor, MI, 1975. An introductory
analysis with applications to biology, control, and artificial intelligence.
[5] S. Kirkpatrick, C. D. Gelatt, and M. P. Vecchi. Optimization by simulated annealing. Science, 220(4598):671–680, 1983.
URL: https://www.science.org/doi/abs/10.1126/science.220.4598.671, arXiv:https://www.science.org/doi/pdf/
10.1126/science.220.4598.671, doi:10.1126/science.220.4598.671.
[6] N. Metropolis, A.W. Rosenbluth, M.N. Rosenbluth, A.H. Teller, and E. Teller. Equation of state calculations by fast computing machines.
The Journal of Chemical Physics, 21(6):1087–1092, 1953.
[7] Nicholas Metropolis and S. Ulam. The Monte Carlo method. J. Amer. Statist. Assoc., 44:335–341, 1949. URL: http://links.jstor.
org/sici?sici=0162-1459(194909)44:247<335:TMCM>2.0.CO;2-3&origin=MSN.
[8] D. W. M. Veldman and E. Zuazua. A framework for randomized time-splitting in linear-quadratic optimal control. Numer. Math.,
151(2):495–549, 2022. doi:10.1007/s00211-022-01290-3.

Silvia Sastre-Gómez

Universidad de Sevilla,Spain

14:50h – 15:30h

Nonlocal Diffusion Equations with Nonlocal reaction.

In this talk we are interested in a nonlocal diffusion equation with a nonlocal reaction
term, which is a nonlinear function g of the mean value of the solution u in a ball centered in x with radius delta. We study the existence and uniqueness of solution of the equation. We give some comparison results under hypotheses on the nonlinear term and the kernel of the nonlocal diffusion operator. Finally we give some asymptotic estimates of the solution of the equation with nonlinear term g globally Lipschitz. We prove the existence of two extremal equilibria and finally we prove that the semigroup is asymptotically smooth, and with this property, we obtain the existence of a global attractor.

About Organization

Juan Limaco -UFF-Coordenador
Mauro Rincon – UFRJ – Brazil
Anna Doubova-U.Sevilla-Spain

Luz de Teresa-UNAM Mexico

Diego Souza – U Sevilla -Spain

Felipe Chaves-UFPB-Brazil

Roberto Capistrano – UFPE Brazil 
Sandra Malta – LNCC – Brazil
Marcelo Cavalcanti – UEM – Brazil;
Rui Almeida – UBI – Portugal
Roxana Lopez – UNMSM – Peru;
Mauricio Sepulveda – UdeC -Chile;

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Seminar June 26 of 2024

Seminar June 26 of 2024

Seminar in EDP and Applied Mathematics

june 26, 2024 – 14h (Brazil)

Streaming: Youtube Channel | SEMINARIO DE EDP E MATEMATICA APLICADA 

Event

About Seminars

Our Online Seminar is one of the most important events in Brazil, it has been held since August 2020, every Wednesday at 2 pm, Brasília time, with a frequency of 14 days. Two 40-minute lectures are presented in each session. Our speakers are world-renowned mathematicians from Europe, the United States and South America.

Featured Talks & Speakers

Giovanni Fantuzzi

Department of Mathematics, FAU Erlangen-Nürnberg,Germany

14:00h – 14:40h

Moment-Sum-of-Squares relaxations for variational problems

Moment-Sum-of-Squares (moment-SOS) relaxations are an established technique to compute converging sequences of lower bounds on the global minimum of finite-dimensional polynomial optimization problems. In this talk, I will discuss two recent extensions of moment-SOS relaxations to infinite-dimensional variational problems, where a (possibly nonconvex) integral functional is to be minimized over functions from a Sobolev space. The first extension optimizes so-called “null Lagrangian translations” and returns certified lower bounds on the global minimum of the variational problem. The second extension, instead, produces upper bounds by approximating minimizers of finite element discretizations of the variational problem. Conditions that ensure the convergence of these upper and lower bounds to the desired global minimum will be discussed, and current gaps between theory and practice will be illustrated by means of examples.

Song Yongcun

Department of Mathematics, FAU Erlangen-Nürnberg,Germany

14:50h – 15:30h

Physics-informed neural networks for non-smooth PDE-constrained optimization problems

We study the application of well-known physics-informed neural networks (PINNs) for solving non-smooth PDE-constrained optimization problems. First, we consider a class of PDE-constrained optimization problems where additional nonsmooth regularization is employed for constraints on the control or design variables. For solving such problems, we combine the alternating direction method of multipliers (ADMM) and PINNs and propose the ADMM-PINNs algorithmic framework, which unties the PDE constraints and the nonsmooth regularization terms for iterations. Accordingly, at each iteration, one of the resulting subproblems is a smooth PDE-constrained optimization which can be efficiently solved by PINNs, and the other is a simple nonsmooth optimization problem which usually has a closed-form solution or can be efficiently solved by various standard optimization algorithms or pre-trained neural networks. Then, we consider the optimal control of PDEs with interfaces. We employ the recently developed discontinuity-capturing neural network to tackle the non-smoothness of the PDEs with interfaces and propose hard-constraint PINNs for solving such optimal control problems. The hard-constraint PINNs ensure both the boundary and interface conditions are satisfied strictly, and meanwhile, they are decoupled from the learning of the PDEs.  All these PINNs methods are mesh-free, easy to implement, and scalable to different PDE settings. Various numerical results are reported to validate the effectiveness and efficiency of the proposed PINNs methods. 

About Organization

Juan Limaco -UFF-Coordenador
Mauro Rincon – UFRJ – Brazil
Anna Doubova-U.Sevilla-Spain

Luz de Teresa-UNAM Mexico

Diego Souza – U Sevilla -Spain

Felipe Chaves-UFPB-Brazil

Roberto Capistrano – UFPE Brazil 
Sandra Malta – LNCC – Brazil
Marcelo Cavalcanti – UEM – Brazil;
Rui Almeida – UBI – Portugal
Roxana Lopez – UNMSM – Peru;
Mauricio Sepulveda – UdeC -Chile;

Our Partners

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A channel for students, professors, researchers and professionals who wish to deepen their knowledge in EDP and applied mathematics.

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Seminar June 12 of 2024

Seminar June 12 of 2024

Seminar in EDP and Applied Mathematics

june 12, 2024 – 14h (Brazil)

Streaming: Youtube Channel | SEMINARIO DE EDP E MATEMATICA APLICADA 

Event

About Seminars

Our Online Seminar is one of the most important events in Brazil, it has been held since August 2020, every Wednesday at 2 pm, Brasília time, with a frequency of 14 days. Two 40-minute lectures are presented in each session. Our speakers are world-renowned mathematicians from Europe, the United States and South America.

Featured Talks & Speakers

Gabriel Paternain

Cambridge University UK

14:00h – 14:40h

Geometric inverse problems in 2D: a transport twistor perspective.

 I will discuss some landmark results in geometric inverse
problems in 2D from the point of view of the transport twistor space, a natural complex surface designed to be sensitive to the geodesic vector field. Towards the end of the lecture I will present some recent developments and open questions motivated by this point of view.

Cristian Morales Rodrigo

Universidad de Sevilla Spain

14:50h – 15:30h

Local and Nonlocal problems in elliptic PDEs.

 This talk is devoted to some local and nonlocal problems by the sub-supersolution method and topological methods. We will focus on different kind of nonlinearities (logistic, sublinear and concave-convex).

About Organization

Juan Limaco -UFF-Coordenador
Mauro Rincon – UFRJ – Brazil
Anna Doubova-U.Sevilla-Spain

Luz de Teresa-UNAM Mexico

Diego Souza – U Sevilla -España

Felipe Chaves-UFPB-Brazil

Roberto Capistrano – UFPE Brazil 
Sandra Malta – LNCC – Brazil
Marcelo Cavalcanti – UEM – Brazil;
Rui Almeida – UBI – Portugal
Roxana Lopez – UNMSM – Peru;
Mauricio Sepulveda – UdeC -Chile;

Our Partners

Access our channel!

A channel for students, professors, researchers and professionals who wish to deepen their knowledge in EDP and applied mathematics.

Contact Us

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