Analysis of Control Systems on Symmetric Cones

It is well known that exploiting special structure is a powerful way to extend the reach of current optimization tools to higher dimensions. While many linear control systems can be treated satisfactorily with linear matrix inequalities (LMI) and semidefinite programming (SDP), practical considerations can still restrict scalability of general methods. Thus, we wish to work with high dimensional systems without explicitly forming SDPs. To that end, we exploit a particular kind of structure in the dynamics matrix, paving the way for a more efficient treatment of a certain class of linear systems. We show how second order cone programming (SOCP) can be used instead of SDP to find Lyapunov functions that certify stability. This framework reduces to a famous linear program (LP) when the system is internally positive, and to a semidefinite program (SDP) when the system has no special structure

Evolució i tendències en l'ocupació del sòl a les illes balears

Se analizan los cambios de ocupación del suelo en las Islas Baleares para el período 1956-2000, así como los potenciales de crecimiento que posibilitan los planes territorial, profundizando en el estudio de las cubiertas del suelo urbano-industriales, que tienen la origen en la explosión turísticoinmobiliaria de las Islas Baleares. La transformación territorial que resulta de la incorporación de las islas Baleares al capitalismo global hace que estas cubiertas urbano-industriales pasen de ocupar 7.416 Ha (1956) a 28.746 Ha (2000). A partir de los planes vigentes, la cubierta urbano-industrial podría alcanzar, potencialmente, unas 38.120 Ha para el 2015, con la siguiente distribución de superficies: urbano (32.360 Ha), viario (2966 Ha), ferroviario (252 Ha), golf (1189 Ha) y canteras (1353 Ha).This study analyses the changes in land use in the Balearic Islands during the 1956-2000 period and the growth potential generated by the planning policy, while examining the industrial and urban coverage of land caused by the tourism and real estate boom in the Islands. The land transformation stemming from the Balearic Islands’ entry into global capitalism gave rise to the growth of urban and industrial land, which went from 7,416 ha. in 1956 to 28,746 ha. in 2000. Based on the current planning model, the urban and industrial coverage could potentially reach some 38,120 ha. by around 2015, with the following distribution: urban (32,360 ha.), roads (2966 ha.), railway (252 ha.), golf (1189 ha.) and quarries (1353 ha.)

Photon Subtraction by Many-Body Decoherence

We experimentally and theoretically investigate the scattering of a photonic quantum field from another stored in a strongly interacting atomic Rydberg ensemble. Considering the many-body limit of this problem, we derive an exact solution to the scattering-induced spatial decoherence of multiple stored photons, allowing for a rigorous understanding of the underlying dissipative quantum dynamics. Combined with our experiments, this analysis reveals a correlated coherence-protection process in which the scattering from one excitation can shield all others from spatial decoherence. We discuss how this effect can be used to manipulate light at the quantum level, providing a robust mechanism for single-photon subtraction, and experimentally demonstrate this capability

El papel de las crisis en la producción, destrucción y reestructuración de los espacios turísticos. El caso de las Islas Baleares

The outbreak of the Great Crisis in 2008 has awakened the interest in the role of crisis within social sciences. Nevertheless, broadly speaking, tourism studies have given very little attention to the moments of crisis. In the case of the Balearic Islands, while there are important works on the historical evolution of the tourist space, those tend to consider crises as blank moments. For this reason, this article focuses on the role played by crises in the production of the Balearics’ space, by analyzing both moments of destruction and restructuring of the political economy. From the understanding of the different crises, from the Civil War to the present, we can conclude that the booms of the Balearic Islands are the indisputable fruit of those crises.El estallido de la Gran Crisis en 2008 ha despertado la reflexión sobre las crisis en el seno de las ciencias sociales. Sin embargo, los estudios turísticos han prestado mayoritariamente poca atención a los momentos de crisis. Pese a que en el caso de las Islas Baleares hay importantes trabajos sobre la evolución histórica del espacio turístico, en estos las crisis suelen considerarse como momentos en blanco. Por ello, este artículo se centra en el papel que las crisis han jugado en la producción del espacio balear, analizando tanto los momentos de destrucción como los de reestructuración de la economía política. A partir de la comprensión de las diferentes crisis, desde la Guerra Civil hasta la actual, se concluye que los booms turísticos baleares son fruto indiscutible de aquellas crisis.This research has been funded by the Spanish Ministry of Economy and Competitiveness. Project title: Crisis and restructuring of the Spanish coastal tourism areas (CSO2015-64468-P)

Using Social Networking Game to Teach Operations Research and Management Science Fundamental Concepts

This paper presents our experience using the popular game FarmVille by Zynga® to teach the fundamentals of linear programming and integer programming concepts to undergraduate students in an introductory operations research course. FarmVille is a popular game within the social networking website Facebook®. A month-long contest was introduced amongst the students with the goal to be the best individual farmer by striving to reach high levels of revenue, experience, and aesthetic appeal of their own unique farm. The contest is to demonstrate the concepts of problem formulation, solution methods, multiple and competing objectives, implementation of policy, and reformulation. The students were surveyed at the beginning of the semester to gain insight into their perceptions of the course. The students were also surveyed regarding the FarmVille Challenge, to gauge the effectiveness of the pedagogy and students\u27 opinions of the hand on approach. The paper demonstrates through surveyed results that the students favored this instruction. The students surveyed agree that this was an engaging and thought provoking exercise and saw the true application of multiple key fundamentals of operations research

HABITABILIDAD Y AIRBNB: EL ALQUILER DE LA VIVIENDA EN EL DISTRITO CENTRO DE MADRID

The irruption of the tourist rental, like the one offered on Airbnb, has brought profound changes around housing and urban spaces. Madrid has become the hand of the tourist rental, among other reasons, in a successful touristic city. This article analyses the proliferation of tourist rentals in the Central district of Madrid and its impact on residential rentals. In this case, as in other European and North American cities, the tourist exploitation of the houses has allowed to open the rent gap, while the rental price of the houses has skyrocketed.La irrupción del alquiler turístico, como el ofertado en Airbnb, ha provocado profundos cambios en torno a la vivienda y en los espacios urbanos. Así, Madrid se ha convertido de la mano del alquiler turístico, en una exitosa ciudad turística. En este artículo se analiza la proliferación del alquiler turístico en el distrito Centro de Madrid y su incidencia sobre el alquiler residencial. En este caso, como en otras ciudades europeas y norteamericanas, la explotación turística de las viviendas ha abierto la brecha de renta, mientras que el alquiler de las viviendas se ha disparado

The fishing footprint of a tourism-based economy: displacing seafood consumption from local to distant waters in the Balearic Islands

Since the Balearics are one of the key tourism destinations in Europe, the tourism industry has entailed a radical transformation of coastal life on the islands. In the 1960s and 1970s, fish captures increased enormously due to the expansion of consumption derived from tourism, and through technological improvements. There has been a change in target species from cheap fish consumed by local people towards expensive species consumed by tourists. However, since the 1980s a combination of factors including the adoption of the EU Common Fisheries Policy, the globalization of trade, and overfishing of some target species has led to a drastic fall in fishing sector jobs, catch reductions, and an increase in cheap imports. This article analyses the transformation of Balearic fisheries combining ecological economics (EE) and political ecology (PE) approaches. Material flow accounting (MFA) and the ecological footprint (EF) are applied in order to conceptualize the biophysical dimension of fisheries in relation to the historical dynamics of capital in the archipelago. Between 1940 and 2012, total fish catches doubled the official landings, while nonreported or hidden catches were underestimated. In the neoliberal period (1990-2012), fish catches decreased and seafood consumption was satisfied mainly through imports, five times the local captures. Thus, the metabolism of fish consumption in the Balearics illustrates the logics of capital and its metabolism in advanced capitalist regions, characterized by the displacement of socio-ecological conflicts to distant waters. Keywords: Balearic Islands; tourism; fisheries; material flow accounting; ecological footprint

Concesión del Premio Luz Marina García Herrera al mejor artículo de Scripta Nova (2020)

La evaluación de los artículos se realizó en dos fases hasta finales de julio de 2020, cuando finalmente el jurado decidió que el mejor artículo de 2020 era el de Michael Byrne: Los «bancos malos» y la resolución de la crisis financiero-inmobiliaria en Europa. La selección de este artículo no fue fácil, ya que el resto de los artículos seleccionados eran también de gran calidad y respondían a aspectos de enorme interés social. De hecho, una de las virtudes de la revista reside en la amplitud temática y de enfoques que alberga. Sin embargo, eso también añade más complejidad a la hora de decidir un premio de estas características. En cualquier caso, consideramos que el artículo premiado resulta muy novedoso en la geografía crítica de habla hispana al profundizar en los giros institucionales, mediante la creación de los “bancos malos” como solución espacial a la crisis financiero-inmobiliaria, y destacar cómo, tras la crisis, se intensifican los circuitos globales del capital financiero-inmobiliario. Precisamente, la relevancia de la temática viene corroborada por el hecho que el primer dosier monográfico de la revista en 2021 se ha dedicado precisamente al complejo urbano financiero inmobiliario en América Latina