Two Globally Convergent Adaptive Speed Observers for Mechanical Systems

A globally exponentially stable speed observer for mechanical systems was recently reported in the literature, under the assumptions of known (or no) Coulomb friction and no disturbances. In this note we propose and adaptive version of this observer, which is robust vis--a--vis constant disturbances. Moreover, we propose a new globally convergent speed observer that, besides rejecting the disturbances, estimates some unknown friction coefficients for a class of mechanical systems that contains several practical examples

Re-Reforming the Bostonian System: A Novel Approach to the Schooling Problem

This paper proposes the notion of E-stability to conciliate Pareto efficiency and fairness. We propose the use of a centralized procedure, the Exchanging Places Mechanism. It endows students a position according with the Gale and Shapley students optimal stable matching as tentative allocation and allows the student to trade their positions. We show that the final allocation is E-stable, i.e. efficient, fair and immune to any justifiable objection that students can formulate.School allocation problem, Pareto efficient matching

Cómo la arquitectura desaparece para ser más arquitectura: el proceso de la Mediateca de Sendai

El edificio de la Mediateca de Sendai en Japón del arquitecto Toyo Ito se presenta como un prototipo arquitectónico paradigmático. Es una obra reconocida profesionalmente por sus valores formales, técnicos y funcionales. Se ha expuesto de manera amplia y extensa en la prensa especializada de arquitectura. Una exposición que paradójicamente se ha convertido en un exceso de información que ha velado, cambiado y pervertido las palabras del arquitecto acerca del proceso de construcción del edificio hasta ocultarlo. Hecho que deja sin valor el acontecimiento que ha supuesto la ideación colectiva de la nueva institución y proyecto de arquitectura. Este artículo muestra otra versión que abre posibilidades para la gobernanza de las obras públicas, y que sin embargo a los arquitectos y otros técnicos todavía les cuesta entender. Una versión que sirve de ejemplo para una gobernanza posible en arquitectura relacionada con los procesos colectivos productores de autonomía, que no está muy alejada del carácter del Movimiento 15M: horizontalidad, transparencia, apertura, procesos colectivos, democracia directa, prácticas de autonomía..

A Taste of Brown: Alimentary Anthropology Between Michoacan and Washington

Growing demands for alternative diets are filtered from the perspective of nation- building and agro-food employees in Washington State. Refusing food as the antithesis of death, brownness emerges as a conceptual frame that foregrounds multiple bodies and actors (human animals, nonhuman animals, and matter) simultaneously as it holds onto ways of being-in-common within scarcity and disavowal. “Sensing Inhumanity” inhabits the limits of nationalist political mobilization for brown bodies by exploring labor embodiment (pesticides, pharmaceuticals, and the sun) and the criminalization of food and color itself (illegalized food trucks and police brutality). Multimedia (video, images, and geographic information systems) and ethnographic writing invite a collective witnessing to our own obligations to the violence constitutive of food production in the U.S. today. Ultimately, how would it feel to embrace a synaesthetic politics of brown alimentary obligation

Impact on soil degradation factors of changes in rain intensity patterns in southern Spain

In southern of Spain, the torrential nature of the rainfalls alters the soil water availability for vegetation and, consequently, its spatially and temporally pattern. This fact, combined with the current global warming, raises a modification of the eco-geomorphological processes dynamics in Mediterranean areas