Respuesta no lineal y criterios de diseño de puentes arco espaciales

El desarrollo más reciente de los puentes arco ha llevado a una nueva tipología: los “puentes arco espaciales”. Se entiende por puente arco espacial todo puente arco en el que, por su configuración geométrica y estructural, las cargas gravitatorias generan esfuerzos no contenidos en el plano del arco. Por un lado, aparecen para satisfacer las necesidades funcionales cuando estructuras en arco resultan las más adecuadas para sostener tableros curvos y evitar así apoyos intermedios. Desde un punto de vista estético, surgen como demanda de los nuevos puentes en entornos urbanos, buscando, no sólo una forma cuidada, sino persiguiendo convertirse en emblemas de la ciudad a partir de la originalidad y la innovación. Su proyecto y construcción es posible gracias a las grandes posibilidades que ofrecen los nuevos métodos de cálculo y dibujo por ordenador, en los que, a través del incremento de memoria y rapidez, cada vez se emplean programas más completos y nuevas modelizaciones, más cercanas a la realidad. No menos importante es el desarrollo de los medios auxiliares de construcción y de las herramientas de CAD/CAM, que convierte en construibles por control numérico formas de manufactura impensables. Ello trasciende en infinitas posibilidades de diseño y estructura. Sin embargo, el diseño y construcción de estas nuevas tipologías no ha estado acompañado por el avance en el estado del conocimiento fundamentado en la investigación, ya que se han desarrollado pocos estudios que explican parcialmente la respuesta estructural de estos puentes. Existe, por lo tanto, la necesidad de profundizar en el estado del conocimiento y clarificar su respuesta estructural, así como de plantear, finalmente, criterios de diseño que sirvan de apoyo en las fases de concepción y de proyecto a estas nuevas tipologías.

A critical application of securitization theory: overcoming the normative dilemma of writing security

This article addresses the normative dilemma located within the application of `securitization,’ as a method of understanding the social construction of threats and security policies. Securitization as a theoretical and practical undertaking is being increasingly used by scholars and practitioners. This scholarly endeavour wishes to provide those wishing to engage with securitization with an alternative application of this theory; one which is sensitive to and self-reflective of the possible normative consequences of its employment. This article argues that discussing and analyzing securitization processes have normative implications, which is understood here to be the negative securitization of a referent. The negative securitization of a referent is asserted to be carried out through the unchallenged analysis of securitization processes which have emerged through relations of exclusion and power. It then offers a critical understanding and application of securitization studies as a way of overcoming the identified normative dilemma. First, it examines how the Copenhagen School’s formation of securitization theory gives rise to a normative dilemma, which is situated in the performative and symbolic power of security as a political invocation and theoretical concept. Second, it evaluates previous attempts to overcome the normative dilemma of securitization studies, outlining the obstacles that each individual proposal faces. Third, this article argues that the normative dilemma of applying securitization can be avoided by firstly, deconstructing the institutional power of security actors and dominant security subjectivities and secondly, by addressing countering or alternative approaches to security and incorporating different security subjectivities. Examples of the securitization of international terrorism and immigration are prominent throughout.

Territorial autonomy and self-determination conflicts: opportunity and willingness cases from Bolivia, Niger, and Thailand

The paradox of autonomy is about whether self-rule accommodates or exacerbates armed conflict. This study attempts to unpack the puzzle examining the effectiveness of territorial autonomy as a state response to self-determination conflicts throughout the world. It challenges the conflict-inducing features of autonomy arguing that territorial autonomy can mitigate armed conflict by channeling group grievances into peaceful forms of protest. Thus, this study aims at arriving at a comprehensive theory that identifies which factors are responsible for violent escalation of conflicts grounded in self-determination demands. By using the concepts of opportunity structures and willingness dimension, this study shows that conflict escalation only takes place when minorities with greater bargaining power vis-à-vis the center, in contexts of high levels of economic inequality within dyad, are mobilized around autonomy and separatist demands.

Paraphrasing : scope and typology : a computational approach

This PhD project aims to study paraphrasing, initially understood as the different ways in which the same content is expressed linguistically. We will go into that concept in depth trying to define and delimit its scope more accurately. In that sense, we also aim to discover which kind of structures and phenomena it covers. Although there exist some paraphrasing typologies, the great majority of them only apply to English, and focus on lexical and syntactic transformations. Our intention is to go further into this subject and propose a paraphrasing typology for Spanish and Catalan combining lexical, syntactic, semantic and pragmatic knowledge. We apply a bottom-up methodology trying to collect evidence of this phenomenon from the data. For this purpose, we are initially using the Spanish Wikipedia as our corpus. The internal structure of this encyclopedia makes it a good resource for extracting paraphrasing examples for our investigation. This empirical approach will be complemented with the use of linguistic knowledge, and by comparing and contrasting our results to previously proposed paraphrasing typologies in order to enlarge the possible paraphrasing forms found in our corpus. The fact that the same content can be expressed in many different ways presents a major challenge for Natural Language Processing (NLP) applications. Thus, research on paraphrasing has recently been attracting increasing attention in the fields of NLP and Computational Linguistics. The results obtained in this investigation would be of great interest in many of these applications.

Mechanisms of agglomeration: Evidence from the location of new manufacturing firms in Spain

El objetivo de esta investigación es aportar evidencia sobre las fuentes de las economías de aglomeración para el caso español. De todas las maneras posibles que se han tomado en la literatura para medir las economías de aglomeración, nosotros lo analizamos a partir de las decisiones de localización de las empresas manufactureras. La literatura reciente ha puesto de relieve que el análisis basado en la disyuntiva localización / urbanización (relaciones dentro de un mismo sector) no es suficiente para entender las economías de aglomeración. Sin embargo, las relaciones entre los diferentes sectores sí resultan significativas al examinar por qué las empresas que pertenecen a diferentes sectores se localizan unas al lado de las otras. Con esto en mente, intentamos explicar que relaciones entre diferentes sectores pueden explicar coaglomeración. Para ello, nos centramos en aquellas relaciones entre sectores definidos a partir de los mecanismos de aglomeración de Marshall, es decir, labor market, input sharing y knowledge spillovers. Trabajamos con el labor market pooling en la medida en que los dos sectores utilizan los mismos trabajadores (clasificación de ocupaciones). Con el segundo mecanismo de Marshall, input sharing, introducimos cómo dos sectores tienen una relación de comprador / vendedor. Por último, nos referimos a dos sectores que utilizan las mismas tecnologías en cuanto a los knowledge spillovers. Con el fin de capturar todos los efectos de los mecanismos de aglomeracion en España, en esta investigación trabajamos con dos ámbitos geográficos, los municipios y los mercados de trabajo locales. La literatura existente nunca se ha puesto de acuerdo en cual es el ámbito geográfico en el que mejor trabajan los mecanismos Marshall, por lo que hemos cubierto todas las unidades geográficas potenciales.

Projectes d’autoaprenentatge de Biologia Cel·lular a la Llicenciatura de Medicina

Aquest projecte de MQD ha permès realitzar una sèrie d’experiències diverses i valuoses que han apuntat formes alternatives en la docència de la Biologia Cel·lular i l’aprenentatge de l'estudiant de la llicenciatura o del grau de medicina. En base a la valoració qualitativa del grau de satisfacció dels usuaris i en un estudi antitatiu de la seva opinió, considerem que ha estat experiències molt vàlides que afavoreixen que l’alumne participi de forma més activa en la seva formació. La principal dificultat observada ha estat o millor dit serà, l’aplicació de les experiències desenvolupades, de forma obligatòria i generalitzada, a tots els alumnes, sobretot als de 1er curs, donat que es tracta d’un grup molt nombrós (més de 300 alumnes). De totes maneres l’experiència adquirida ha estat molt favorable. Les activitats desenvolupades es continuen aplicant i es continuaran aplicant en el nou pla de medicina. Una aplicació perllongada en cursos successius afavorirà poder extreure’n conclusions de tipus més quantitatiu a més de les apreciacions qualitatives.

Structural decomposition analysis and input-output subsystems: An application to Spanish CO2 emissions

Analysis of gas emissions by the input-output subsystem approach provides detailed insight into pollution generation in an economy. Structural decomposition analysis, on the other hand, identifies the factors behind the changes in key variables over time. Extending the input-output subsystem model to account for the changes in these variables reveals the channels by which environmental burdens are caused and transmitted throughout the production system. In this paper we propose a decomposition of the changes in the components of CO2 emissions captured by an input-output subsystems representation. The empirical application is for the Spanish service sector, and the economic and environmental data are for years 1990 and 2000. Our results show that services increased their CO2 emissions mainly because of a rise in emissions generated by non-services to cover the final demand for services. In all service activities, the decomposed effects show an increase in CO2 emissions due to a decrease in emission coefficients (i.e., emissions per unit of output) compensated by an increase in emissions caused both by the input-output coefficients and the rise in demand for services. Finally, large asymmetries exist not only in the quantitative changes in the CO2 emissions of the various services but also in the decomposed effects of these changes. Keywords: structural decomposition analysis, input-output subsystems, CO2 emissions, service sector.

On the automatic application of inequality indexes in the analysis of the international distribution of environmental indicators

In recent years traditional inequality measures have been used to quite a considerable extent to examine the international distribution of environmental indicators. One of its main characteristics is that each one assigns different weights to the changes that occur in the different sections of the variable distribution and, consequently, the results they yield can potentially be very different. Hence, we suggest the appropriateness of using a range of well-recommended measures to achieve more robust results. We also provide an empirical test for the comparative behaviour of several suitable inequality measures and environmental indicators. Our findings support the hypothesis that in some cases there are differences among measures in both the sign of the evolution and its size. JEL codes: D39; Q43; Q56. Keywords: international environment factor distribution; Kaya factors; Inequality measurement

Mixture of bivariate Poisson regression models with an application to insurance

In a recent paper Bermúdez [2009] used bivariate Poisson regression models for ratemaking in car insurance, and included zero-inflated models to account for the excess of zeros and the overdispersion in the data set. In the present paper, we revisit this model in order to consider alternatives. We propose a 2-finite mixture of bivariate Poisson regression models to demonstrate that the overdispersion in the data requires more structure if it is to be taken into account, and that a simple zero-inflated bivariate Poisson model does not suffice. At the same time, we show that a finite mixture of bivariate Poisson regression models embraces zero-inflated bivariate Poisson regression models as a special case. Additionally, we describe a model in which the mixing proportions are dependent on covariates when modelling the way in which each individual belongs to a separate cluster. Finally, an EM algorithm is provided in order to ensure the models’ ease-of-fit. These models are applied to the same automobile insurance claims data set as used in Bermúdez [2009] and it is shown that the modelling of the data set can be improved considerably.

Modified differentials and basic cohomology for Riemannian foliations

We define a new version of the exterior derivative on the basic forms of a Riemannian foliation to obtain a new form of basic cohomology that satisfies Poincaré duality in the transversally orientable case. We use this twisted basic cohomology to show relationships between curvature, tautness, and vanishing of the basic Euler characteristic and basic signature.

Application of the combined integral method to Stefan problems

In this paper we present a new, accurate form of the heat balance integral method, termed the Combined Integral Method (or CIM). The application of this method to Stefan problems is discussed. For simple test cases the results are compared with exact and asymptotic limits. In particular, it is shown that the CIM is more accurate than the second order, large Stefan number, perturbation solution for a wide range of Stefan numbers. In the initial examples it is shown that the CIM reduces the standard problem, consisting of a PDE defined over a domain specified by an ODE, to the solution of one or two algebraic equations. The latter examples, where the boundary temperature varies with time, reduce to a set of three first order ODEs.

MEVA-Ambiental: MEtodologia per a la Valoració de l'Aprenentatge. Centrada en l'educació ambiental

Aquest projecte abasta el disseny i el desenvolupament d’un model prototípic de Metodologia per a la Valoració de l’Aprenentatge Ambiental, a la qual anomenem “MEVA-Ambiental”. Per a fer possible aquesta fita ens hem basat en fonaments ontològics i constructivistes per representar i analitzar el coneixement a fi de poder quantificar l’Increment de Coneixement (IC). Per nosaltres l’IC esdevé un indicador socio-educatiu que ens servirà per a determinar l’efectivitat dels tallers d’educació ambiental en percentatge. En procedir d’aquesta manera, les qualificacions resultats poden es poden prendre com punt de partida per a desenvolupar estudis en el temps i comprendre com “s’ancora” el nou coneixement a l’estructura cognitiva dels aprenents. Més enllà del plantejament teòric de mètode, també proveïm la solució tècnica que mostra com n’és de funcional i d’aplicable la part empírica metodològica. A aquesta solució que hem anomenat “MEVA-Tool”, és una eina virtual que automatitza la recollida i tractament de dades amb una estructura dinàmica basada en “qüestionaris web” que han d’emplenar els estudiants, una “base de dades” que acumula la informació i en permet un filtratge selectiu, i més “Llibre Excel” que en fa el tractament informatiu, la representació gràfica dels resultats, l’anàlisi i conclusions.

Re-opening the black box in societal metabolism: the application of MuSIASEM to water

In this paper we address the complexity of the analysis of water use in relation to the issue of sustainability. In fact, the flows of water in our planet represent a complex reality which can be studied using many different perceptions and narratives referring to different scales and dimensions of analysis. For this reason, a quantitative analysis of water use has to be based on analytical methods that are semantically open: they must be able to define what we mean with the term “water” when crossing different scales of analysis. We propose here a definition of water as a resource that deal with the many services it provides to humans and ecosystems. WE argue that water can fulfil so many of them since the element has many characteristics that allow for the resource to be labelled with different attributes, depending on the end use –such as drinkable. Since the services for humans and the functions for ecosystems associated with water flows are defined on different scales but still interconnected it is necessary to organize our assessment of water use across different hierarchical levels. In order to do so we define how to approach the study of water use in the Societal Metabolism, by proposing the Water Metabolism, tganized in three levels: societal level, ecosystem level and global level. The possible end uses we distinguish for the society are: personal/physiological use, household use, economic use. Organizing the study of “water use” across all these levels increases the usefulness of the quantitative analysis and the possibilities of finding relevant and comparable results. To achieve this result, we adapted a method developed to deal with multi-level, multi-scale analysis - the Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MuSIASEM) approach - to the analysis of water metabolism. In this paper, we discuss the peculiar analytical identity that “water” shows within multi-scale metabolic studies: water represents a flow-element when considering the metabolism of social systems (at a small scale, when describing the water metabolism inside the society) and a fund-element when considering the metabolism o ecosystems (at a larger scale when describing the water metabolism outside the society). The theoretical analysis is illustrated using two case which characterize the metabolic patterns regarding water use of a productive system in Catalonia and a water management policy in Andarax River Basin in Andalusia.

Application of ZnO-Functionalised-Sepiolite in weaning piglet diets

The objective was to evaluate the effect of ZnO-Functionalised-Sepiolite (ZnO-Sepiolite) to fulfil Zn requirements and health status of weaning piglets. Pre-starter Basal Diet (BD, corn– soybean based, from weaning till 14 days on trial) was calculated to provide 27 mg Zn/kg feed from raw materials and had no added ZnO and no antibiotics or organic acids. Treatments during pre-starter period were: 1) BD+90% of NRC Zn requirements completed with ZnO (ZnO90); 2) BD+90% of NRC Zn requirements completed with ZnO-Sepiolite (ZnOS90); 3) BD+3000 mg ZnO/kg of diet (ZnO3000); 4) BD+150 mg added Zn/kg diet from ZnO-Sepiolite (ZnOS150). The starter feed (corn–soybean based, from 14 till 31 days on trial) was common for all piglets, and met 90% NRC Zn requirements by adding ZnO. Diarrhea affected more than 50% of the animals of ZnO90, ZnOS90 and ZnOS150, and 33% of the ZnO3000 animals. Animals from ZnOS90 tended (Pb0.10) to improve Gain to Feed ratio (G:F) compared to animals from ZnO90 (0.830 kg/kg vs. 0.811 kg/kg for G:F). Performance of animals from ZnO3000 was not significantly different from the other treatments, and was numerically similar to animals from ZnOS90. The inclusion of ZnO at 3000 mg/kg of feed in the pre-starter period numerically decreased P in serum at the end of this period, with no effect on Ca level; normal levels were restored after 2 weeks of feeding the same levels of Zn than other animals. Animals fed ZnOSepiolite diets had numerically higher serum Ca than ZnO90 and ZnO3000 at 12 days and higher than ZnO90 at 28 days. Serum Zn levels were significantly higher for ZnO3000 than the other treatments.

Aplicación de la ingeniería del software sobre la herramienta MATE : application controller

Este proyecto tiene como objetivo crear y aplicar una metodología a una aplicación llamada MATE que fue creada en en el año 2003 por Anna Sikora para su tesis doctoral. Se trata de dotar el proyecto MATE de las herramientas necesarias para garantizar su evolución. La metodología creada consta de la especificación de un entorno de trabajo y una serie de documentos que detallan los procesos relativos al desarrollo de MATE. Además se han creado algunas nuevas características que hacen de MATE una herramienta más completa y cómoda.