Seminars

Oracle-Augmented Prophet Inequalities.

Event Date: Nov 30, 1999 in ACGO, Seminars

Abstract:  In the top-1-of-k prophet inequality setting, a gambler is given a sequence of n random variables X_1, …, X_n, taken from known distributions, observes their values in an adversarial order, and selects up to k of them, immediately after they are observed, so that the top value selected is as high as possible, comparing against a prophet who always selects the maximum realization. For k = 1, one recovers the classical prophet inequality, and thus this model serves as a generalization. In this talk, we look at a new approach to solve the top-1-of-k model. We generalize the...

Análisis de áreas quemadas a partir de imágenes de sensores remotos en el Parque Estadual do Cocó, Región Metropolitana de Fortaleza (Ceará).

Event Date: Apr 19, 2024 in Ciclo de Seminarios conjuntos CopLAC-Chile, Seminars

Resumen: El Parque Estadual do Cocó (PEC), situado en Fortaleza, capital del estado de Ceará, representa la mayor reserva urbana del Norte/Nordeste de Brasil y la cuarta en extensión en América Latina. Sin embargo, enfrenta diversos desafíos que comprometen su biodiversidad y su función ecológica. Estos incluyen incendios forestales, la expansión descontrolada de áreas urbanas, la fragmentación del hábitat debido al desarrollo de infraestructuras y carreteras, así como la contaminación del agua y del suelo, además de presiones derivadas de actividades humanas como la tala ilegal de árboles y...

Characterisation of the Set of Ground States of Uniformly Chaotic Finite-Range Lattice Models.

Event Date: Apr 15, 2024 in Dynamical Systems, Seminars

RESUMEN: The study of statistical physics models allows mathematics to offer another perspective on empirically observable phenomena. A point of interest is in particular the behavior of these models when the temperature tends towards 0, analogous to the emergence of complex crystal structures in materials. A way to model that is to consider tiling defined by local rules where some matching rules can be broken proportionally to a parameter which is the inverse of the temperature. This correspond to the Gibbs measure of the system and we are interested to the stability of these measures when...

Análisis de áreas quemadas a partir de imágenes de sensores remotos en el Parque Estadual do Cocó (Fortaleza, Brasil)

Event Date: Apr 19, 2024 in Ciclo de Seminarios quincenales de la Alianza Copernicus-Chile, Seminars

Expositor: Mauricio Perea, ingeniero forestal y estudiante de doctorado en Geografía de la Universidade Federal do Ceará (Brasil). Fecha y hora: viernes 19 de abril, 12:00 hrs. de Chile (16:00 UTC). Resumen: El Parque Estadual do Cocó (PEC), situado en Fortaleza, capital del estado de Ceará, representa la mayor reserva urbana del Norte/Nordeste de Brasil y la cuarta en extensión en América Latina. Sin embargo, enfrenta diversos desafíos que comprometen su biodiversidad y su función ecológica. Estos incluyen incendios forestales, la expansión descontrolada de áreas urbanas, la fragmentación...

Sobre la topología de ciertos grupos de difeomorfismos.

Event Date: Apr 08, 2024 in Dynamical Systems, Seminars

Event Date: Apr 10, 2024 in ACGO, Seminars

Abstract:  In this talk, I will give an introduction to linear programming hierarchies, with a particular focus on the hierarchy by Sherali & Adams. I will discuss some limitations of the tool, but also ways to get useful and stronger relaxations.