Noticimat: 29

Seminario de Cuantificación de Incertidumbre

Lunes 15

Título: Sphere stepping algorithms for Dirichlet-type problems with the fractional Laplacian
Ponente: Andreas Kyprianou (Department of Mathematical Sciences, The University of Bath)
Lugar: Salón K201
Hora: 4:00 pm
Resumen: Abstract: We review the sphere-stepping algorithm for simulating the solution to the classical Dirichlet problem and consider whether the same can be done when the Laplacian can be changed to the fractional Laplacian. Whereas in the former case, we need knowledge about isotropic Brownian motion, in the latter case, we need information about isotropic stable Levy processes. We will show that the stable case offers a “faster” convergence than in the Brownian case thanks to the trajectory of stable processes having jumps.

Seminario de Estadística Espacial

Martes 16

Tema: Median Polish Kriging
Ponente: Eduardo Álvarez Rodríguez (CIMAT)
Lugar: Salón K201
Hora: 3:00 pm
Resumen: En algunas ocasiones es de interés realizar predicciones a partir de  datos observados. En estadística para datos espaciales, se cuenta con varios predictores capaces de realizar dicha actividad. Entre ellos está el predictor Kringing pulido por la mediana (Median Polish Kringing). Está basado en la estimación robusta de la estructura media y la estimación de la estructura del error de un proceso aleatorio que genera datos espaciales. Dichas estimaciones se realizan mediante el uso del algoritmo de pulido por la mediana (Median Polish), mejorando las desventajas producidas por el estimador de interpolaciones planas.

Seminario de Álgebra Conmutativa

Martes 16

Título: Introducción al álgebra conmutativa combinatoria
Ponente: Luis Núñez Betancourt (CIMAT)
Lugar: Por confirmar
Hora: 4:30 pm

Seminario de Probabilidad (Sesión doble extraordinaria)

Miércoles 17

Título: When does noise disturb a deterministic system?
Ponente: Gotz Kersting (Goethe University, Frankfurt am Main)
Lugar: Salón de seminarios “Diego Bricio Hernández” (G101)
Hora: 1:00 pm
Resumen: We discuss stochastic processes X which can be considered as deterministic systems Y perturbed by some random noise. The question is, whether properties of Y are preserved in the noisy system X or whether they are eliminated. In the talk we address different models, with discrete or continuous time and with values in one-dimensional or higher dimensional space. Altogether a general scheme crystallizes showing that there is a precise borderline outside of which the noise becomes the predominant component of the models. This borderline does not depend on the models dimension.

Título: The interplay of two mutations in a population of varying size: a stochastic eco-evolutionary model for clonal interference
Ponente: Charline Smadi Lasserre (Institut des Systemes Complexes, Paris Ile-de-France)
Lugar: Salón de seminarios “Diego Bricio Hernández” (G101)
Hora: 4:00 pm
Resumen: Joint work with Sylvain Billiard. Clonal interference, competition between multiple beneficial mutations, has a major role in adaptation of asexual populations.

We provide a simple stochastic model of clonal interference taking into account a wide variety of competitive interactions.

The population evolves as a three-type birth-and-death process with type dependent competitions. This allows us to relax the classical assumption of transitivity between mutations, and to predict genetic patterns, such as coexistence of several mutants or emergence of Rock-Paper-Scissors cycles, which were not explained by existing models. In addition, we call into questions some classical preconceived ideas about fixation time and fixation probability of competing mutations.

Seminario de Robótica y Sistemas Inteligentes (RSI)

Viernes 19