[Todos] Nuevo Seminario del Instituto de Cálculo: Lunes 22 de Julio, 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.