El Gratis (1842-1843): aproximación al estudio de un periódico innovador

El presente trabajo expone el análisis de El Gratis, diario de anuncios publicado en 1842-43, algunas de cuyas características (aplicación de la ley del doble mercado, distribución gratuita de parte de los ejemplares, edición de un diario-cartel…) representan una verdadera novedad para la época y para la historia del periodismo decimonónico en España.

Stability in Linear Optimization Under Perturbations of the Left-Hand Side Coefficients

This paper studies stability properties of linear optimization problems with finitely many variables and an arbitrary number of constraints, when only left hand side coefficients can be perturbed. The coefficients of the constraints are assumed to be continuous functions with respect to an index which ranges on certain compact Hausdorff topological space, and these properties are preserved by the admissible perturbations. More in detail, the paper analyzes the continuity properties of the feasible set, the optimal set and the optimal value, as well as the preservation of desirable properties (boundedness, uniqueness) of the feasible and of the optimal sets, under sufficiently small perturbations.