Suchergebnisse

Mención Internacional en el título de doctor ; In this thesis we address the problem of Air Traffic Flow Management (ATFM). In brief, this problem consists of finding optimal schedules and routes for a set of flights in such a way that, when the flight plans are executed, no region of the airspace has more aircraft flying over it than allowed by security restrictions. Likewise, no airport should be assigned more departures or arrivals than it can handle. In the thesis, continuing a research line originated some decades ago, we cope with this problem using mathematical optimization. The thesis content is organized as follows. In Chapter 2 we give a detailed description of the ATFM problem and review some of the most recent works that also employ mathematical programming to tackle the problem. The chapter also contains our modeling proposals for the ATFM problem. These consist of two new and equivalent 0-1 mathematical programming formulations. The formulations are shown to be an easy way to model different complex situations arising in practice, and permit to solve some limitations of the state-of-the-art models. The chapter concludes presenting a novel methodology to detect, beforehand, routes that will be part of the optimal solution. In Chapter 3 we generalize some of the results obtained in Chapter 2. Concretely, we introduce a family of shortest path problems that, to the best of our knowledge, has not been previously investigated: the Shared Resource Constrained Multi-Shortest Path Problem. In the chapter we show how to use this family of shortest path problems to solve some type of project scheduling problems. This way, the results obtained in the previous chapter for the ATFM problem are extended to a broader family of scheduling problems. In Chapter 3 we also discuss two different solution methods for the family of shortest path problems presented. The first method consists of a matheuristic algorithm, while the second one is based on two Lagrangian Relaxations of the problem. Chapter 4 contains an extensive computational experience to validate the results presented in the previous chapters. Moreover, the chapter includes the creation of ATFM instances which have been released for free disposal. Finally, in Chapter 5 we summarize the main conclusions and contributions accomplished in the thesis. Future lines of research that this work opens are also discussed there. ; En esta tesis tratamos el problema de la Gestión de Flujo del Tráfico Aéreo (ATFM). De manera breve, este problema consiste en encontrar una planificación temporal y de rutas óptima para un conjunto de vuelos de manera que, cuando se ejecuten los planes de vuelo, ninguna región del espacio aéreo tenga más aeronaves volando sobre ella que las permitidas por las restricciones de seguridad. Asimismo, no se debe asignar a ningún aeropuerto más salidas o llegadas de las que pueda manejar. En la tesis, continuando una línea de investigación originada hace algunas décadas atrás, abordamos este problema mediante optimización matemática. El contenido de la tesis está organizado de la siguiente manera. En el capítulo 2 damos una descripción detallada del problema del ATFM y revisamos algunos de los trabajos más recientes que también emplean optimización matemática para abordar el problema. El capítulo también contiene nuestras propuestas de modelización para el problema del ATFM. Estas consisten en dos nuevas y equivalentes formulaciones 0-1 de optimización matemática. En el capítulo se muestra como dichas formulaciones permiten modelar de manera sencilla diferentes situaciones complejas que surgen en la práctica, y cómo permiten resolver algunas limitaciones de los modelos que conforman el estado del arte. El capítulo concluye presentado una nueva metodología para detectar, de antemano, rutas que formarán parte de la solución óptima. En el capítulo 3 generalizamos algunos de los resultados obtenidos en el capítulo 2. Concretamente, introducimos una familia de problemas de camino mínimo que, hasta nuestro entender, no ha sido investigada previamente: el problema de múltiples caminos mínimos con recursos compartidos y restringidos. En el capítulo mostramos cómo usar esta familia de problemas de camino mínimo para resolver algunos problemas de planificación de proyectos. De esta manera, los resultados obtenidos en el capítulo anterior para el problema del ATFM se extienden a una familia más amplia de problemas de planificación. En el capítulo 3 también presentamos dos métodos de resolución diferentes para la familia de problemas de camino mínimo presentada. El primer método consiste en un algoritmo matheurístico, mientras que el segundo se basa en dos Relajaciones Lagrangianas del problema. El capítulo 4 contiene una extensa experiencia computacional para validar los resultados presentados en los capítulos anteriores. Además, el capítulo incluye la creación de instancias para el problema del ATFM que han sido liberadas para su libre disposición. Finalmente, en el capítulo 5 resumimos las principales conclusiones y contribuciones realizadas en la tesis. También se discuten las futuras líneas de investigación que este trabajo abre. ; This research was partially funded by projects MTM2015-63710-P and RTI2018-094269-B-I00 (A. Alonso-Ayuso and D. García-Heredia) from the Government of Spain. ; Programa de Doctorado en Ingeniería Matemática por la Universidad Carlos III de Madrid ; Presidente: Laureano F. Escudero Bueno.- Secretario: Francisco Javier Prieto Fernández.- Vocal: Sergio García Quiles

How the structures of opportunity, power, and relative numbers affect officers' behaviors and attitudes.

AbstractIn the wake of the 1990 amendments to the Clean Air Act, localities across the United States initiated public
information campaigns both to raise awareness of threats to air quality and to change behavior related to air
pollution by recommending specific behavioral changes in the campaign messages. These campaigns are designed to
reduce the health hazards associated with poor air quality and to avoid federal sanctions resulting from the
failure to meet air quality standards. As in many other communities across the country, a coalition of government
agencies and businesses initiated a public information campaign in the Atlanta metropolitan region to reduce
certain targeted behaviors, mainly driving. A two‐stage model used to analyze data from a rolling sample
survey shows that the centerpiece of the information campaign—air quality alerts—was effective in
raising awareness and reducing driving in a segment of the population. When the overall information campaign was
moderated by employers' participation in programs to improve air quality, drivers significantly reduced the
number of miles they drove and the number of trips they took by car on days when air quality alerts were sounded.
Public information campaigns can be successful in increasing awareness, but changing well‐established
behaviors, such as driving, is likely to require institutional mediation to provide social contexts that support
the behavioral change, as well. © 2003 by the Association for Public Policy Analysis and Management.

This article addresses the concept of en plein air regarding men's fashion in early twentieth-century Italy. The act of painting outdoors has been addressed at length in the field of art history as one of the most radical practices of nineteenth-century avantgardes. It focused on the changing appearance of light and weather conditions, as in the case of the renowned French Impressionist painters, who often represented women and their clothing in the natural environment. However, en plein air can also provide an opportunity to reframe men's fashion in its relationship with the environment. The Italian painter and dandy Filippo de Pisis (1896–56) relied on en plein air to constitute his peculiar vision of 'pictorial elegance', connecting painting skills with the experience of wearing clothes in open spaces, for instance, during a stroll in the Mediterranean sunshine. This article analyses de Pisis's artworks and writings on male elegance and its pictorial qualities, aiming to explore the under-investigated invisibility of men's fashion in the early twentieth century. By doing so, it challenges the misogyny of the antifashion rhetoric of Modernist aesthetics. The case of de Pisis is particularly interesting in this regard because it provides an illuminating pictorial and textual affective interpretation of the interdependences between men's bodies, the colours and fabrics of their clothes and the qualities of the open-air environment in which they were experienced. This contribution intends to shed light on the concept of 'pictorial elegance' that was for de Pisis a queer, destabilizing and poetic transfiguration of masculinity in the context of European Modernism.

El artículo analiza la conflictiva implementación de la libertad de imprenta en Buenos Aires tras la caída del régimen rosista. Para ello examina tanto la normativa vigente y los proyectos para modificarla, como lo sucedido en algunos juicios, el accionar del gobierno y los debates en la legislatura y en la prensa. El estudio pone en discusión la interpretación canónica que enfatiza que en esos años rigió una amplia libertad de expresión en la provincia. Asimismo, y en una mirada de más largo plazo, sostiene que las dificultades para implementar la libertad de imprenta durante el siglo XIX se vincularon a la tensión provocada por la consideración de la prensa como un pilar de las sociedades republicanas y civilizadas y, a la vez, como un agente corrosivo del orden. ; This paper analyzes the conflictive implementation of freedom of the press in Buenos Aires, after the fall of Rosas' regime. It examines norms and the initiatives to reform them, some trials, government actions, and the debates within the legislature and the press. The study discusses the traditional interpretation according to which, in the province of Buenos Aires, those years were characterized by a wide freedom of expression. It also argues that the difficulties to implement freedom of the press in the 19th century are explained by the tension between the consideration of the press as a pillar of civilized, republican societies and, at the same time, as a corrosive agent of the social and political order.

The relationship between air transportation and urbanization at the national scale is investigated in order to illustrate its role in the post-war evolution of the Turkish urban system. Theory suggests that major transportation innovations have exhibited profound and prolonged interdependencies with patterns of growth in national or regional urban systems. As the most recent major intercity transportation innovation, it should be expected that utilization of air transportation should bear some relationship to patterns of growth in urban places. This paper investigates this relationship by using government air transportation data and Turkish Census data to correlate volumes of air passenger flows per capita with changes in population and employment for the 24 largest Turkish metropolitan areas and cities.The expectation that higher volumes of air passenger flow per capita exhibit a positive correlation with both previous and subsequent growth is confirmed by the analysis. At the same time, this relationship is investigated at the regional and provincial level. The results illustrate the importance of balance of air transportation and airport planning in balance urbanization and economic development of the provincies and regions. Further, especially increasing importance of Turkey's location as a result of globalisation requires the rapid and efficient development of hierarchical airport system in order to stimulate overall development and balanced urbanization.

El trabajo estudia la evolución en la distribución de la propiedad de la tierra en el sector rural de Buenos Aires entre los años centrales del gobierno de Rosas y los inicios de etapa liberal, utilizando como fuentes principales unos censos económicos realizados por motivos fiscales, así como los padrones de población. Se observa una creciente desigualdad general que se puede asociar a las limitaciones en la oferta de tierra junto a un importante incremento demográfico. Pero a la vez se encuentran divergencias regionales significativas que se busca explicar por un conjunto de motivos que van desde la orientación productiva, las condiciones iniciales desiguales de poblamiento y parcelamiento de la tierra en cada lugar, así como los procesos de urbanización, entre otros. ; This article studies the evolution in land property distribution in the rural sector of Buenos Aires between the central years of Rosas government and the beginning of the liberal era, employing as its principal sources some economic censuses taken for fiscal purposes and some population lists. We observe a global increase in inequality that may be associated with the limitations in land availability alongside an important demographic growth. But we also find significant regional differences that can be explained by a number of reasons among which are the productive profile, the initial conditions of population density and land distribution, and the urbanization process, among others.

"Suffocating smog regularly envelops Chinese metropolises from Beijing to Shanghai, clouding the future prospect of China's growth sustainability. Air pollutants do not discriminate between the rich and the poor, the politician and the 'average Joe.' They put everyone's health and economic prosperity at risk, creating future costs that are difficult to calculate. Yet many people, including some in China, are concerned that addressing environmental challenges will jeopardize economic growth. In 'The Economics of Air Pollution in China, ' leading Chinese economist Ma Jun makes the case that the trade-off between growth and environment is not inevitable. In his ambitious proposal to tackle severe air pollution and drastically reduce the level of so-called PM 2.5 particles--microscopic pollutants that lodge deeply in lungs--Ma Jun argues that in targeting pollution, China has a real opportunity to undertake significant structural economic reforms that would support long-term growth. Rooted in rigorous analyses and evidence-based projections, Ma Jun's 'big bang' proposal aims to mitigate pollution and facilitate a transition to a greener and more sustainable growth model."--JSTOR website (viewed March 7, 2017)

AbstractThe paper explores the aerial dimension of policing and surveillance. It does so by drawing upon select results from a large‐scale survey conducted in 2017 among professional (public and private) drone users in Switzerland. Focusing in particular on the police, the paper shows that the technology not only generates novel ways of looking down from above, but also of looking up from below, thus instilling a kind of air‐mindedness among the police. In making the airspace explicit as an object, and stake of imaginaries, concerns and practices, drones mediate novel ways of relating to the air, understanding it, approaching it and acting in relation to it.

AbstractThe implementation of participatory budgeting in Buenos Aires following the crisis of December 2001 was a highly unlikely event. The different parties involved had competing and contradictory agendas that did not coincide with participatory budgeting's stated aims of extending citizen participation in government, but these interacted in a way that contingently created a space for a viable process to develop. Subsequent political shifts led to the demise of participatory budgeting, but the Buenos Aires case is nevertheless important because it highlights the way in which such processes can emerge in the absence of strong programmatic politics, thereby potentially opening new avenues for the promotion of democratic innovation.