Seminars

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.

 

A Study of the Difference-of-Convex Approach for Solving Linear Programs with Complementarity Constraints

Event Date: Sep 05, 2018 in Optimization and Equilibrium, Seminars

Abstract:   This work studies the difference-of-convex (DC) penalty formulations and the associated difference-of-convex algorithm (DCA) for computing stationary solutions of linear programs with complementarity constraints (LPCCs). We focus on two such formulations and establish connections between their stationary solutions and those of the LPCC. Improvements of the DCA are proposed to remedy some drawbacks in a straightforward adaptation of the DCA to these formulations. Extensive numerical results, including comparisons with an...

Strong Algorithms for the Ordinal Matroid Secretary Problem

Event Date: Sep 05, 2018 in AGCO, Seminars

Abstract: A general technique and analysis for the matroid secretary problem is presented and then we show how to achieve a 4-competitive algorithm for the case of graphic matroids.

SEMINAR CAPDE de EDPs

Event Date: Sep 03, 2018 in CAPDE, Seminars

SEMINAR CAPDE de EDPs   Primera Sesión 16:00 hs. Expositor Panayotis Smyrnelis DIM-CMM Universidad de Chile   Title Minimal heteroclinics for second and fourth order O.D.E systems   Segunda Sesión 17:00 hrs.   Expositor Chulkwang Kwak (PUC)   Title Well-posedness issues of some dispersive equations under the periodic boundary condition.   Abstract: In this talk, we are going to discuss about the well-posedness theory of dispersive equations (KdV- and NLS-type equations) posed on T, via analytic methods. I am going to briefly explain some...

El potencial de los satélites para estudiar y monitorear eventos hidrometeorológicos extremos.

Event Date: Sep 03, 2018 in Ciclo de Seminarios quincenales de la Alianza Copernicus-Chile, Seminars

Seminarios de la Alianza Copernicus-Chile Titulo El potencial de los satélites para estudiar y monitorear eventos hidrometeorológicos extremos. Expositor Roberto Rondanelli, U. de Chile Sala:  Sala Multimedia, Centro de Modelamiento Matemático, Beauchef 851, Edificio Norte, Piso 6. Fecha:  Lunes 03 de Septiembre de 2018 Hora:  16:00 horas Participación en Linea:...

Minicurso Mating of trees a cargo de Avelio Sepulveda (Université Lyon 1).

Event Date: Sep 03, 2018 in Seminars

Mating of trees: una aproximación discreta.   El objetivo de este mini-curso es introducir ciertos modelos canónicos de espacios métricos aleatorios discretos y obtener sus límites continuos. Para ello comenzaremos analizando los árboles aleatorios y probando su convergencia al CRT (continuous random tree). Luego, definiremos las cartas aleatorias uniformes ( uniform random planar maps) y estudiaremos su  convergencia como espacio métrico y cómo esta convergencia se relaciona con ciertos árboles contenidos en la carta. Finalmente,...

A (5/3 + ε)-Approximation for Unsplittable Flow on a Path: Placing Small Tasks into Boxes

Event Date: Aug 29, 2018 in AGCO, Seminars

Abstract:  In the unsplittable flow on a path problem (UFP) we are given a path with edge capacities and a collection of tasks. Each task is characterized by a subpath, a profit, and a demand. Our goal is to compute a maximum profit subset of tasks such that, for each edge e, the total demand of selected tasks that use e does not exceed the capacity of e. The current best polynomial-time approximation factor for this problem is 2 + eps for any constant eps>0. This is the best known factor even in the case of uniform edge capacities. These...

MST en grafos con incertidumbre y cómo encontrarlos con consultas de mínimo costo.

Event Date: Aug 22, 2018 in AGCO, Seminars

Abstract: En esta presentación estudiaremos el problema de MST en un contexto donde los pesos son inciertos. Dado un grafo, para cada arista se conocerá un conjunto no vacío que contiene los posibles pesos de la arista. Eventualmente los verdaderos pesos se darán a conocer y llamamos a esto una realización de los pesos. Los algoritmos a considerar tendrán acceso a una operación especial llamada “consulta” que revela de manera inmediata el verdadero peso de una arista a cierto costo predeterminado. Nos enfocaremos en los siguientes...

Dynamics of strongly interacting 2-solitons for dispersive equations

Event Date: Aug 20, 2018 in CAPDE, Seminars

Abstract:   The theory of linear dispersive equations predicts that waves should spread out and disperse over time. However, it is a remarkable phenomenon, observed both in theory and practice, that once there are nonlinear effects, many nonlinear dispersive equations (for example: NLS, gKdV, coupled NLS,…) admit special “compact” solutions, called solitary wave or solitons, whose shape does not change in time. A multi-soliton is a solution which is close to a superposition of several solitons. The problem we address is...

Sistemas Dinámicos de Santiago Dynamical Day

Event Date: Aug 20, 2018 in Dynamical Systems, Seminars

Primera Sesión:  14:30 hrs. Speaker:          Mike Todd (University of St Andrews, United Kingdom). Title:   Phase transitions and limit laws. Abstract:         The `statistics’ of a dynamical system is the collection of statistical limit laws it satisfies.  This starts with Birkhoff’s Ergodic Theorem, which is about averages of some observable along orbits: this is a pointwise result, for typical points for a given invariant measure.  Then we can look for forms of Central Limit Theorem, Large Deviations and so on: these are about how...