Involutivity of the Hamilton-Cartan equations of a second-order Lagrangian admitting a first-order Hamiltonian formalism

Involutivity of the Hamilton-Cartan equations of a second-order Lagrangian admitting a first-order Hamiltonian formalism

Large-scale testing of proficiency in English: Back to multiple choice?

The paper analyses whether that a properly designed multiple choice test can discriminate with a high level of accuracy if a student in our context has reached a B2 level according to the CEFRL.

Mathematical modelling of neural processes within the oculomotor system

It is presented a mathematical model of the oculomotor plant, based on experimental data in cats. The system that generates, from the neuronal processes at the motoneuron, the control signals to the eye muscles that moves the eye. In contrast with previous models, that base the eye movement related motoneuron behavior on a first order linear differential equation, non-linear effects are described: A dependency on the eye angular position of the model parameters.

Optically Reconfigurable RF Circuits using Silicon Switches

Mobile and wireless communications systems have become an important part of our everyday lives. These ubiquitous technologies have a profound effect on how we live. People predict bright future to wireless technologies, but it wouldn’t be possible without a hard work of thousands of scientists in the wireless innovation research arena. My Marie Curie project is investigating enabling technologies for future mobile and wireless communications systems

El parque: Espacios, límites y jerarquías en la obra de SANAA

En los últimos tiempos, el estudio japonés SANAA ha realizado una serie de obras que le han puesto en el punto de mira de la arquitectura internacional, y que se ha visto reflejado en la concesión en el año 2010 del premio Pritzker a Kazuyo Sejima y Ryue Nishizawa por toda una carrera de trabajo ininterrumpido. SANAA ha construido una serie de edificios que han supuesto una gran influencia en el contexto de la arquitectura mundial y que está contribuyendo al trabajo de muchísimos arquitectos jóvenes, tanto en Japón como fuera de él, y su trabajo se estudia y analiza en las escuelas de arquitectura de medio mundo. La tesis doctoral, estudia el parque de SANAA desde las diversas formas en las que éste se presenta, parques por continuidad, o parques por acumulación, como una excusa para el estudio de los diferentes mecanismos arquitectónicos en los que se basa su modo de proyectar. Dichos mecanismos forman parte ya de una forma de proyectar contemporánea y su estudio permite la comprensión de algunos de los fenómenos arquitectónicos más interesantes que se están produciendo en la arquitectura de nuestro tiempo. La revelación de estos mecanismos supone el sacar a la luz gran parte de los procesos y desarrollos de proyecto, que por la lacónica manera de dibujar de SANAA, quedan ocultos la mayoría de las veces y, tan solo es percibido en una visita lenta y pausada por el edificio. El documento aquí presentado se convierte entonces, en una investigación, en la que el doctorando, como un detective, rastrea los proyectos de SANAA buscando aquellos mecanismos que permiten discernir el verdadero significado de conceptos como laberinto, jerarquía, orden, atmósfera o experiencia a lo largo de los principales proyectos de espacio horizontal de Sejima y Nishizawa. La tesis intenta por tanto dar forma a las principales referencias que constituyen el universo imaginario del estudio japonés y que, ya son parte de la cultura arquitectónica contemporánea. ABSTRACT In recent times, the Japanese Studio SANAA has produced a number of works that have taken it to the front sight of international architecture. This has led Kazuyo Sejima and Ryue Nishizawa to receiving the 2010 Pritzer award for an uninterrupted career. SANAA has built a series of buildings that have greatly influenced global architecture. Moreover, it is contributing to the work of many young architects, both in Japan and outside Japan. Its work is studied and assessed by architecture schools all over the world. This Doctoral thesis analyses the SANAA Park from all the perspectives it shows, parks by continuity or parks by accumulation, as an excuse to study different architectural mechanisms in which its way of projecting is based. Such mechanisms already are part of a contemporaneous way of projecting. In addition, its analysis allows for the further understanding of some of the most interesting architectural phenomena that are being produced nowadays. The release of these mechanisms entails shedding a light to most of the proceedings and courses of the project that, because of the SANAA’s laconic way of designing, remain hidden most of the times and are often noticed through a slow and thorough look at the building. This document becomes then a work of research, where the Doctorate, as a detective, tracks SANAA’s projects, searching for those mechanisms that allow for truly defining the meaning of concepts such as maze, hierarchy, order, atmosphere and experience throughout Sejima’s and Nishizawa’s main horizontal space projects. Therefore, this thesis aims at shaping key references that constitute the imaginary universe of the Japanese study and that already are part of the contemporaneous architectural culture.

A survey on service quality description

Quality of service (QoS) can be a critical element for achieving the business goals of a service provider, for the acceptance of a service by the user, or for guaranteeing service characteristics in a composition of services, where a service is defined as either a software or a software-support (i.e., infrastructural) service which is available on any type of network or electronic channel. The goal of this article is to compare the approaches to QoS description in the literature, where several models and metamodels are included. consider a large spectrum of models and metamodels to describe service quality, ranging from ontological approaches to define quality measures, metrics, and dimensions, to metamodels enabling the specification of quality-based service requirements and capabilities as well as of SLAs (Service-Level Agreements) and SLA templates for service provisioning. Our survey is performed by inspecting the characteristics of the available approaches to reveal which are the consolidated ones and which are the ones specific to given aspects and to analyze where the need for further research and investigation lies. The approaches here illustrated have been selected based on a systematic review of conference proceedings and journals spanning various research areas in computer science and engineering, including: distributed, information, and telecommunication systems, networks and security, and service-oriented and grid computing.

Farmers behaviour on mitigation and adaptation to climate change: A case study in Kenya.

Farmers in Africa are facing climate change and challenging rural livelihoods while maintaining agricultural systems that are not resilient. By 2050 the mean estimates of production of key staple crops in Africa such as maize, sorghum, millet, groundnut, and cassava are expected to decrease by between 8 and 22 percent (Schlenker and Lobell 2010). In Kenya, although projections of rainfall do not show dramatic decreases, the distribution of impacts is clearly negative for most crops. As increases in temperature will lead to increases in evapotranspiration, a potential increase in rainfall in Kenya may not offset the expected increases in agricultural water needs (Herrero et al. 2010). In order to respond to these present and future challenges, potential mitigation and adaptation options have been developed. However, implementation is not evident. In addition to their benefits in either mitigating or reducing the vulnerability of climate change effects, many of these options do not have economic costs and even provide economic benefits (e.g. savings in the consumption of energy or natural resources). Nevertheless, it is demonstrated that even when there are no biophysical, technological or economic constraints and despite their potential benefits from either the economic or environmental climate change point of view, not all farmers are willing to adopt these measures. This reflects the key role that behavioural barriers can play in the uptake of mitigation and adaptation measures.

Metodología para la estimación de indicadores armonizados a partir de los inventarios forestales nacionales europeos con especial énfasis en la biodiversidad forestal

Durante las últimas décadas el objetivo principal de la silvicultura y la gestión forestal en Europa ha pasado de ser la producción de madera a ser la gestión sostenible de los ecosistemas, por lo que se deben considerar todos los bienes y servicios que proporcionan los bosques. En consecuencia, es necesario contar con información forestal periódica de diversos indicadores forestales a nivel europeo para apoyar el desarrollo y la implementación de políticas medioambientales y que se realice una gestión adecuada. Para ello, se requiere un seguimiento intensivo sobre el estado de los bosques, por lo que los Inventarios Forestales Nacionales (IFN), (principal fuente de información forestal a gran escala), han aumentado el número de variables muestreadas para cumplir con los crecientes requerimientos de información. Sin embargo, las estimaciones proporcionadas por los diferentes países no son fácilmente comparables debido a las diferencias en las definiciones, los diseños de muestreo, las variables medidas y los protocolos de medición. Por esto, la armonización de los datos que proporcionan los diferentes países es fundamental para la contar con una información forestal sólida y fiable en la Unión europea (UE). La presente tesis tiene dos objetivos principales: (i) establecer el diseño de una metodología para evaluar la biodiversidad forestal en el marco del Inventario forestal nacional de España teniendo en cuenta las diferentes iniciativas nacionales e internacionales, con el objetivo de producir estimaciones comparables con las de otros países de la UE y (ii) armonizar los indicadores más relevantes para satisfacer los requerimientos nacionales e internacionales. Como consecuencia del estudio realizado para alcanzar el primer objetivo, la metodología diseñada para estimar la biodiversidad fue adoptada por el Tercer Inventario forestal nacional. Ésta se componía de indicadores agrupados en: cobertura del suelo, composición de árboles y especies de arbustos, riqueza de especies herbáceas y helechos, especies amenazadas, estructura, madera muerta, y líquenes epífitos. Tras el análisis del diseño metodológico y de los datos proporcionados, se observó la conveniencia de modificarla con el fin de optimizar los costes, viabilidad, calidad y cantidad de los datos registrados. En consecuencia, en el Cuarto Inventario Forestal Nacional se aplica una metodología modificada, puesto que se eliminó el muestreo de especies herbáceas y helechos, de líquenes epífitos y de especies amenazadas, se modificaron los protocolos de la toma de datos de estructura y madera muerta y se añadió el muestreo de especies invasoras, edad, ramoneo y grado de naturalidad de la masa. En lo que se refiere al segundo objetivo, se ha avanzado en la armonización de tres grupos de variables considerados como relevantes en el marco de los IFN: los indicadores de vegetación no arbórea (que juegan un papel relevante en los ecosistemas, es donde existe la mayor diversidad de plantas y hasta ahora no se conocían los datos muestreados en los IFN), la determinación de los árboles añosos (que tienen un importante papel como nicho ecológico y su identificación es especialmente relevante para la evaluación de la biodiversidad forestal) y el bosque disponible para el suministro de madera (indicador básico de los requerimientos internacionales de información forestal). Se llevó a cabo un estudio completo de la posible armonización de los indicadores de la vegetación no arbórea en los IFN. Para ello, se identificaron y analizaron las diferentes definiciones y diseños de muestreo empleados por los IFN, se establecieron definiciones de referencia y se propusieron y analizaron dos indicadores que pudiesen ser armonizados: MSC (mean species cover) que corresponde a la media de la fracción de cabida cubierta de cada especie por tipo de bosque y MTC (mean total cover). Se estableció una nueva metodología que permite identificar los árboles añosos con los datos proporcionados por los inventarios forestales nacionales con el objetivo de proporcionar una herramienta eficaz para facilitar la gestión forestal considerando la diversidad de los sistemas forestales. Se analizó el concepto de "bosque disponible para el suministro de madera" (FAWS) estudiando la consistencia de la información internacional disponible con el fin de armonizar su estimación y de proporcionar recomendaciones para satisfacer los requerimientos europeos. Como resultado, se elaboró una nueva definición de referencia de FAWS (que será adoptada por el proceso paneuropeo) y se analiza el impacto de la adopción de esta nueva definición en siete países europeos. El trabajo realizado en esta tesis, puede facilitar el suministrar y/o armonizar parcial o totalmente casi la mitad de los indicadores de información forestal solicitados por los requerimientos internacionales (47%). De éstos, prácticamente un 85% tienen relación con los datos inventariados empleando la metodología propuesta para la estimación de la biodiversidad forestal, y el resto, con el establecimiento de la definición de bosque disponible para el suministro de madera. No obstante, y pese a que esta tesis supone un avance importante, queda patente que las necesidades de información forestal son cambiantes y es imprescindible continuar el proceso de armonización de los IFN europeos. ABSTRACT Over the last few decades, the objectives on forestry and forest management in Europe have shifted from being primarily focused on wood production to sustainable ecosystem management, which should consider all the goods and services provided by the forest. Therefore, there is a continued need for forest indicators and assessments at EU level to support the development and implementation of a number of European environmental policies and to conduct a proper forest management. To address these questions, intensive monitoring on the status of forests is required. Therefore, the scope of National Forest Inventories (NFIs), (primary source of data for national and large-area assessments), has been broadened to include new variables to meet these increasing information requirements. However, estimates produced by different countries are not easily comparable because of differences in NFI definitions, plot configurations, measured variables, and measurement protocols. As consequence, harmonizing data produced at national level is essential for the production of sound EU forest information. The present thesis has two main aims: (i) to establish a methodology design to assess forest biodiversity in the frame of the Spanish National Forest Inventory taking into account the different national and international initiatives with the intention to produce comparable estimates with other EU countries and (ii) to harmonize relevant indicators for national and international requirements. In consequence of the work done related to the first objective, the established methodology to estimate forest biodiversity was adopted and launched under the Third National Forest Inventory. It was composed of indicators grouped into: cover, woody species composition, richness of herbaceous species and ferns, endangered species, stand structure, dead wood, and epiphytic lichens. This methodology was analyzed considering the provided data, time costs, feasibility, and requirements. Consequently, in the ongoing Fourth National Forest Inventory a modified methodology is applied: sampling of herbaceous species and ferns, epiphytic lichens and endangered species were removed, protocols regarding structure and deadwood were modified, and sampling of invasive species, age, browsing impact and naturalness were added. As regards the second objective, progress has been made in harmonizing three groups of variables considered relevant in the context of IFN: Indicators of non-tree vegetation (which play an important role in forest ecosystems, it is where the highest diversity of plants occur and so far the related sampled data in NFIs were not known), the identification of old-growth trees (which have an important role as ecological niche and its identification is especially relevant for the assessment of forest biodiversity) and the available forest for wood supply (basic indicator of international forestry information requirements). A complete analysis of ground vegetation harmonization possibilities within NFIs frame was carried on by identifying and analyzing the different definitions and sampling techniques used by NFIs, providing reference definitions related to ground vegetation and proposing and analyzing two ground vegetation harmonized indicators: “Mean species cover” (MSC) and “Mean total cover” (MTC) for shrubs by European forest categories. A new methodology based on NFI data was established with the aim to provide an efficient tool for policy makers to estimate the number of old-growth trees and thus to be able to perform the analysis of the effect of forest management on the diversity associated to forest systems. The concept of “forest available for wood supply” (FAWS) was discussed and clarified, analyzing the consistency of the available international information on FAWS in order to provide recommendations for data harmonization at European level regarding National Forest Inventories (NFIs). As a result, a new reference definition of FAWS was provided (which will be adopted in the pan-European process) and the consequences of the use of this new definition in seven European countries are analyzed. The studies carried on in this thesis, can facilitate the supply and/or harmonization partially or fully of almost half of the forest indicators (47%) needed for international requirements. Of these, nearly 85% are related to inventoried data using the proposed methodology for the estimation of forest biodiversity, and the rest, with the establishment of the definition of forest available for wood supply. However, despite this thesis imply an important development, forest information needs are changing and it is imperative to continue the process of harmonization of European NFIs.