Bifurcation of solutions through a contact manifold in bidisperse models

This research focuses on a hyperbolic system that describes bidisperse suspensions, consisting of two types of small particles dispersed in a viscous fluid. The dependence of solutions on the relative position of contact manifolds in the phase space is examined. The wave curve method serves as the basis for the first and second analyses. The former involves the classification of elementary waves that emerge from the origin of the phase space. Analytical solutions to prototypical Riemann problems connecting the origin with any point in the state space are provided. The latter focuses on semi-analytical solutions for Riemann problems connecting any state in the phase space with the maximum packing concentration line, as observed in standard batch sedimentation tests. When the initial condition crosses the first contact manifold, a bifurcation occurs. As the initial condition approaches the second manifold, another structure appears to undergo bifurcation, although it does not represent an actual bifurcation according to the triple shock rule. The study reveals important insights into the behavior of solutions in relation to these contact manifolds. This research sheds light on the existence of emerging quasi-umbilic points within the system, which can potentially lead to new types of bifurcations as crucial elements of the elliptic/hyperbolic boundary in the system of partial differential equations. The implications of these findings and their significance are discussed

A simulation model for two-phase pedestrian flow

We introduce a two-dimensional macroscopic model for the simulation of pedestrian flow based on a multiphase approach, which is well suited for the case of intersecting streams. A flow composed of two populations of pedestrians moving in different directions is modeled by a two-dimensional system of convection-diffusion equations. The model is intended to be the basic step of a more complex simulation model. © 2011 American Institute of Physics

Calibración numérica de leyes de conservación escalar vía un algoritmo genético continuo

Our work deals with the flux identication problem for scalar conservation laws. The problem is formulated as an optimization problem, where the objective function compares the solution of thedirect problem with observed proles at a fixed time. A finite volume scheme solves the direct problem and a continuous genetic algorithm solves the inverse problem. The numerical method is tested with synthetic experimental data. Simulation parameters are recovered approximately. The tested heuristic optimization technique turns out to be more robust than classical optimization techniques.En este artículo se investiga sobre el problema de la identificación de parámetros del flujo en una ley de conservación escalar. El problema es formulado como un problema de optimización, donde la función objetivo compara la solución del problema directo con el perfil observado en un tiempo fijo. Un esquema de volúmenes finitos resuelve el problema directo y un algoritmo genético continuo resuelve el problema inverso. El método numérico es verificado con datos experimentales sintéticos. Los parámetros simulados se recuperan aproximadamente. La técnica de optimización heurística probada resulta ser mas robusta que las técnicas clásicas de optimización

Magíster en matemáticas aplicadas de la universidad católica de temuco: una contribución al continuo educativo del profesor de matemática

El Magíster en Matemáticas Aplicadas (MMA) de la Universidad Católica de Temuco es un posgrado profesional, según lo define la Comisión Nacional de Acreditación (2013), que inició sus actividades en marzo del 2014. Su misión es formar graduados que posean las competencias para aplicar la matemática al análisis cuantitativo de sistemas complejos. El objetivo de este póster es informar a la comunidad los avances de su proceso de autoevaluación actualmente en curso

Calibration of a sedimentation model through a continuous genetic algorithm

In this contribution we consider the problem of flux identification in a scalar conservation law modelling the phenomenon of sedimentation. The experimental observation data used for the calibration consist of a solid concentration profile at a fixed time. The identification problem is formulated as an optimization one, where the distance between the profiles of the model simulation and observation data is minimized by a least squares cost function. The direct problem is approximated by a monotone finite volume scheme. The numerical solution of the calibration problem is obtained by a continuous genetic algorithm. Numerical results are presented in order to validate the efficiency of the proposed algorithm

An adaptive finite-volume method for a model of two-phase pedestrian flow

A flow composed of two populations of pedestrians moving in different directions is modeled by a two-dimensional system of convection-diffusion equations. An efficient simulation of the two-dimensional model is obtained by a finite-volume scheme combined with a fully adaptive multiresolution strategy. Numerical tests show the flow behavior in various settings of initial and boundary conditions, where different species move in countercurrent or perpendicular directions. The equations are characterized as hyperbolic-elliptic degenerate, with an elliptic region in the phase space, which in one space dimension is known to produce oscillation waves. When the initial data are chosen inside the elliptic region, a spatial segregation of the populations leads to pattern formation. The entries of the diffusion-matrix determine the stability of the model and the shape of the patterns

Competencias necesarias en graduados de ingeniería según representantes de la industria regional Chilena

En el marco de una media jornada de trabajo con representantes de la industria regional de la región de la Araucanía, en su mayoría de formación de Ingeniero Civil Industrial o áreas afines, aplicamos una serie de instrumentos cualitativos para identificar las competencias necesarias en graduados de ingeniería. Primero se aplicó un cuestionario con ocho preguntas, luego se realizó un análisis FODA donde cada participante formuló una nota para cada ítem (fortaleza, oportunidades, amenaza y debilidades). Finalmente se incentivó una discusión grupal sobre cada uno de estos ítems. Como conclusión, las características más relevantes de egresados para las empresas se pueden distinguir en tres dimensiones: el rol del conocimiento (conocimiento teórico versus conocimiento específico), la visión global del negocio, y la actitud en la vinculación con la empresa