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Employing different loss functions for the classification of images via supervised learning

Radu Boţ, André Heinrich, Gert Wanka (2014)

Open Mathematics

Supervised learning methods are powerful techniques to learn a function from a given set of labeled data, the so-called training data. In this paper the support vector machines approach is applied to an image classification task. Starting with the corresponding Tikhonov regularization problem, reformulated as a convex optimization problem, we introduce a conjugate dual problem to it and prove that, whenever strong duality holds, the function to be learned can be expressed via the dual optimal solutions....

Enlarged Asymptotic Compensation in Discrete Distributed Systems

L. Afifi, M. Hakam, M. Bahadi, A. El Jai (2010)

Mathematical Modelling of Natural Phenomena

This work concerns an enlarged analysis of the problem of asymptotic compensation for a class of discrete linear distributed systems. We study the possibility of asymptotic compensation of a disturbance by bringing asymptotically the observation in a given tolerance zone 𝒞. Under convenient hypothesis, we show the existence and the unicity of the optimal control ensuring this compensation and we give its characterization

Enlarged exact compensation in distributed systems

Larbi Afifi, Abdelhakim Chafiai, Abdelaziz Bel Fekih (2002)

International Journal of Applied Mathematics and Computer Science

In this work, we examine, through the observation of a class of linear distributed systems, the possibility of reducing the effect of disturbances (pollution, etc.), by making observations within a given margin of tolerance using a control term. This problem is called enlarged exact remediability. We show that with a convenient choice of input and output operators (actuators and sensors, respectively), the considered control problem has a unique optimal solution, which will be given. We also study...

Epitaxially strained elastic films: the case of anisotropic surface energies

Marco Bonacini (2013)

ESAIM: Control, Optimisation and Calculus of Variations

In the context of a variational model for the epitaxial growth of strained elastic films, we study the effects of the presence of anisotropic surface energies in the determination of equilibrium configurations. We show that the threshold effect that describes the stability of flat morphologies in the isotropic case remains valid for weak anisotropies, but is no longer present in the case of highly anisotropic surface energies, where we show that the flat configuration is always a local minimizer...

Equazioni di bilancio della meccanica dei continui nell’ambito della teoria geometrica della misura

Alessandro Musesti (2004)

Bollettino dell'Unione Matematica Italiana

Si dà una presentazione della formulazione delle equazioni di bilancio della Meccanica dei Continui tramite l'approccio insiemistico (flussi e interazioni di Cauchy) e quello distribuzionale (potenze virtuali), illustrando i progressi ottenuti nell'indebolimento delle ipotesi, fino a comprendere campi tensoriali a divergenza misura. Si mostra poi come l'approccio attraverso il Principio delle potenze virtuali permetta di individuare il tensore degli sforzi anche nel caso di un corpo continuo dotato...

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