Noticias en español
Seminars appear in decreasing order in relation to date. To find an activity of your interest just go down on the list. Normally seminars are given in English. If not, they will be marked as Spanish Only.
La estructura de sistemas simbólicos de complejidad baja.
RESUMEN: En el contexto de dinámica simbólica, la clase de “subshifts de complejidad lineal” es de particular relevancia, ya que ocurre en una variedad de áreas, tales como sistemas dinámicos geométricos, teoría de lenguajes, teoría de números y sistemas de numeración, entre otros. Durante el intenso estudio de este tema en los noventa, fue propuesto que una descomposición jerárquica basada en secuencias S-ádicas que caracterice a los subshifts de complejidad lineal sería útil para entenderlos. El problema de encontrar tal...
A gluing construction of singular solutions for a fully non-linear equation in conformal geometry.
Abstract: We study construction of a complete non-compact Riemannian metrics with positive constant σ2-curvature, on the sphere Sn with a prescribed singular set Λ given by a disjoint union of closed submanifolds whose dimension is positive and strictly less than n−√n−22 . This is a fully non-linear problem, nevertheless, we show that the classical gluing method of Mazzeo-Pacard for the scalar curvature still works in this setting since the linearized operator has good mapping properties in weighted spaces. A necessary condition is that 2 ≤...
Constructing separating hyperplanes for non-convex quadratic problems.
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...
Acciones docentes que promueven la argumentación en situaciones de modelación.
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...
Fourier transform restriction phenomena and applications to control of dispersive equations.
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...
Una plataforma de monitoreo y alerta temprana de una especie invasora en la Patagonia, el Castor Canadiense.
Resumen: “Las especies invasoras en Chile implican un enorme costo económico, social y ambiental, y su gestión se hace prácticamente imposible en zonas remotas, como la Patagonia. Se hace necesaria una evaluación espacial a gran escala de la expansión actual de la especie, además de sus potenciales rutas de expansión, para poder trazar una estrategia a largo plazo que permita su erradicación. En este proyecto hemos combinado exitosamente herramientas satelitales, modelación ecológica y tecnologías de la información para implementar dos...
A Unified Framework for Symmetry Handling.
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...
Variational techniques for non-trivial boundary conditions in fluid dynamics and beyond.
Abstract: Despite the widely spread usage of no-slip boundary conditions in fluid dynamics, there exist several applications where it is not true that the fluid sticks to the boundary. Instead, the natural condition is setting the normal flux to zero, and then complementing the tangential direction with certain friction conditions known as the Navier boundary condition. In this talk, we will explore the many issues that can arise from strongly imposed boundary conditions in this setting, and how such issues can be alleviated in a way that...
Load Balancing Algorithms on Scheduling Problems with a Concave Function of the Load.
Abstract: In load balancing scheduling problems n jobs are to be assigned to m machines. Each job has its own processing time, and we define the load of a machine as the sum of the processing time of all jobs assigned to it. In this work, the machines have a concave non-decreasing function (accessed through a value oracle) applied to their loads and our goal is to maximize the sum of these valuations. This setting models a productivity maximization of machines where we aim to allocate indivisible resources, such as fuel tanks. We prove the...
