Seminars

Condiciones de grado mínimo para subdivisiones generadoras.

Event Date: Oct 17, 2023 in Seminario de Grafos, Seminars

Resumen: En esta charla mostraremos que en todo grafo con n vértices y grado mínimo ligeramente por sobre n/2 es posible encontrar la subdivisión de un grafo completo, la que además usa todos los vértices del grafo huésped y donde cada arista está subdividida casi la misma cantidad de veces. La demostración es completamente probabilista y no usa ningún tipo de argumento tipo absorción o regularidad.

Dirac operators in a decaying random environment: dynamics and spectral statistics.

Event Date: Oct 11, 2023 in Seminario de Probabilidades de Chile, Seminars

Constructing separating hyperplanes for non-convex quadratic problems.

Event Date: Oct 11, 2023 in ACGO, Seminars

Abstract:  In 1971, Balas introduced the intersection cut framework as a method for generating separating hyperplanes (or “cuts”) in integer optimization. These cuts are derived from convex S-free sets, and inclusion-wise maximal S-free sets yield the strongest intersection cuts. When S is a lattice, maximal S-free sets are well-studied from theoretical and computational standpoints. In this talk, we focus on the case when S is defined by a non-convex quadratic inequality and show how to construct basic maximal quadratic-free sets. Additionally, we explore how to generalize the...

Fourier transform restriction phenomena and applications to control of dispersive equations.

Event Date: Oct 10, 2023 in Differential Equations, Seminars

Abstract: In 93′ Jean Bourgain discovered a subtle smoothing property of solutions of the KdV equation posed on a periodic domain. Since this celebrated article, the smoothing properties for dispersive systems are now well known. In this talk, we will see that in the last 15 years, the Bourgain spaces are fundamental to addressing the global control problems in periodic frameworks. Precisely, we will show that the propagation of compactness and regularity have been observed thanks to these spaces in various control problems for dispersive systems.

Acciones docentes que promueven la argumentación en situaciones de modelación.

Event Date: Oct 10, 2023 in Education, Seminars

RESUMEN El propósito de esta presentación es caracterizar acciones que realizan docentes cuando promueven la argumentación colectiva en problemas de modelación y se enmarca dentro de una investigación más amplia sobre la gestión de clases relacionando las competencias de argumentación y modelación. Desde la perspectiva de la comunicación en el aula, la argumentación debe ser vista como un elemento central, y por tanto deben ser promovida, pues la calidad en el aprendizaje depende de la participación del alumnado en la construcción colectiva de argumentos (Krummheuer, 2007). La...

A Unified Framework for Symmetry Handling.

Event Date: Oct 04, 2023 in ACGO, Seminars

Abstract:  Discrete optimization problems are often solved using constraint programming or mided-integer programming techniques, using enumeration or branch-and-bound techniques. It is well known that if the problem formulation is very symmetric,  there may exist many symmetrically equivalent solutions to the problem. Without handling the symmetries, traditional solving methods have have to check many symmetric parts of the solution space, which comes at a high computational cost. Handling symmetries in optimization problems is thus essential for devising efficient solution methods. In this...