[Todos] Nuevo Seminario del Instituto de Cálculo: HOY 14:30

[gduran en dm.uba.ar]

>
> Seminario de Matemática Aplicada e Industrial del Instituto de Cálculo
>
> Lunes 22 de Julio de 2013 14:30 hs.
> 3 charlas de 45 minutos cada una.
>
> Lugar: Instituto de Cálculo, Segundo Piso, Pabellón II, Ciudad
> Universitaria
>
> Primera Charla:
>
> 14:30  Richard Weber (Profesor Asociado, Departamento de Ingeniería
> Industrial, Universidad de Chile)
>
> Data-Mining para problemas Biotecnológicos
>
> Título de la charla:
>
> Simultaneous feature selection and classification using kernel-penalized
> support vector machines and applications in biotechnology (trabajo
> conjunto con Sebastián Maldonado, Universidad de Los Andes, Chile)
>
> Resumen:
>
> Feature selection is relevant in application domains where many features
> are available for classification, such as e.g. in microarray analysis. We
> introduce an embedded method that simultaneously selects relevant features
> during classifier construction by penalizing each feature’s use in the
> dual formulation of support vector machines (SVM). This approach called
> kernel-penalized SVM (KP-SVM) optimizes the shape of an anisotropic RBF
> Kernel eliminating features that have low relevance for the classifier.
> Additionally, KP-SVM employs an explicit stopping condition, avoiding the
> elimination of features that would negatively affect the classifier’s
> performance. We performed experiments on four real-world benchmark
> problems comparing our approach with well-known feature selection
> techniques. KP-SVM outperformed the alternative approaches and determined
> consistently fewer relevant features.
>
> Segunda Charla:
>
> 15:15 Thomas Pradeau (Ecole des Ponts et Chaussées, Francia; Visiting
> scholar, Universidad Torcuato Di Tella)
>
> Teoría de Juegos
>
> Título de la charla:
>
> Nash equilibrium on rings and uniqueness
>
> Resumen:
>
> We consider congestion games on networks with nonatomic users and
> user-specific costs. We are interested in the uniqueness property defined
> by Milchtaich [Milchtaich, I. 2005. Topological conditions for uniqueness
> of equilibrium in networks. Math. Oper. Res. 30 225-244] as the uniqueness
> of equilibrium flows for all assignments of strictly increasing cost
> functions. He settled the case with two-terminal networks. In the present
> work we characterize completely bidirectional rings for which the
> uniqueness property holds. The main result is that it holds precisely for
> nine networks and those obtained from them by elementary operations. For
> other bidirectional rings, we exhibit affine cost functions yielding to
> two distinct equilibrium flows. Related results are also proven.
>
> 16:00  Coffee-break
>
> Tercera charla:
>
> 16:15 Jorge Barnett Lawton (Posdoctorando en Gestión de Operaciones,
> Universidad Torcuato Di Tella)
>
> Optimización en problemas de Energía
>
> Título:
>
> Hydrogen production facility network design from stochastic renewable
> energy source
>
> Resumen:
>
> Significant emphasis has been placed by policy makers in increasing the
> penetration of renewable energy generation as part of the energy portfolio
> to reduce reliance on fossil fuels. Hydrogen has been identified as a
> clean carrier for storing energy from volatile sources and as an
> alternative fuel for transportation. We present a model for the design of
> a hydrogen distribution network, where hydrogen can be produced using
> energy from a stochastic source, subject to variability in both energy
> supply and prices. We provide solution approaches based on column
> generation, which we then apply to a potential hydrogen supply chain in
> Spain under different production incentive schemes and regulatory
> settings.
>