Interference Management and Energy Efficiency in Satellite Communications

The main areas of research of this thesis are Interference Management and Link-Level Power Efficiency for Satellite Communications. The thesis is divided in two parts. Part I tackles the problem of interference environments in satellite communications, and interference mitigation strategies, not just in terms of avoidance of the interferers, but also in terms of actually exploiting the interference present in the system as a useful signal. The analysis follows a top-down approach across different levels of investigation, starting from system level consideration on interference management, down to link-level aspects and to intra-receiver design. Interference Management techniques are proposed at all the levels of investigation, with interesting results. Part II is related to efficiency in the power domain, for instance in terms of required Input Back-off at the power amplifiers, which can be an issue for waveform based on linear modulations, due to their varying envelope. To cope with such aspects, an analysis is carried out to compare linear modulation with waveforms based on constant envelope modulations. It is shown that in some scenarios, constant envelope waveforms, even if at lower spectral efficiency, outperform linear modulation waveform in terms of energy efficiency.

Un’applicazione di elaborazione del linguaggio naturale per il gioco di "Indovina chi?" su robot umanoide

La tesi è stata incentrata sul gioco «Indovina chi?» per l’identificazione da parte del robot Nao di un personaggio tramite la sua descrizione. In particolare la descrizione avviene tramite domande e risposte L’obiettivo della tesi è la progettazione di un sistema in grado di capire ed elaborare dei dati comunicati usando un sottoinsieme del linguaggio naturale, estrapolarne le informazioni chiave e ottenere un riscontro con informazioni date in precedenza. Si è quindi programmato il robot Nao in modo che sia in grado di giocare una partita di «Indovina chi?» contro un umano comunicando tramite il linguaggio naturale. Sono state implementate regole di estrazione e categorizzazione per la comprensione del testo utilizzando Cogito, una tecnologia brevettata dall'azienda Expert System. In questo modo il robot è in grado di capire le risposte e rispondere alle domande formulate dall'umano mediante il linguaggio naturale. Per il riconoscimento vocale è stata utilizzata l'API di Google e PyAudio per l'utilizzo del microfono. Il programma è stato implementato in Python e i dati dei personaggi sono memorizzati in un database che viene interrogato e modificato dal robot. L'algoritmo del gioco si basa su calcoli probabilistici di vittoria del robot e sulla scelta delle domande da proporre in base alle risposte precedentemente ricevute dall'umano. Le regole semantiche realizzate danno la possibilità al giocatore di formulare frasi utilizzando il linguaggio naturale, inoltre il robot è in grado di distinguere le informazioni che riguardano il personaggio da indovinare senza farsi ingannare. La percentuale di vittoria del robot ottenuta giocando 20 partite è stata del 50%. Il data base è stato sviluppato in modo da poter realizzare un identikit completo di una persona, oltre a quello dei personaggi del gioco. È quindi possibile ampliare il progetto per altri scopi, oltre a quello del gioco, nel campo dell'identificazione.

A triplet spike-timing–dependent plasticity model generalizes the Bienenstock–Cooper–Munro rule to higher-order spatiotemporal correlations

Synaptic strength depresses for low and potentiates for high activation of the postsynaptic neuron. This feature is a key property of the Bienenstock–Cooper–Munro (BCM) synaptic learning rule, which has been shown to maximize the selectivity of the postsynaptic neuron, and thereby offers a possible explanation for experience-dependent cortical plasticity such as orientation selectivity. However, the BCM framework is rate-based and a significant amount of recent work has shown that synaptic plasticity also depends on the precise timing of presynaptic and postsynaptic spikes. Here we consider a triplet model of spike-timing–dependent plasticity (STDP) that depends on the interactions of three precisely timed spikes. Triplet STDP has been shown to describe plasticity experiments that the classical STDP rule, based on pairs of spikes, has failed to capture. In the case of rate-based patterns, we show a tight correspondence between the triplet STDP rule and the BCM rule. We analytically demonstrate the selectivity property of the triplet STDP rule for orthogonal inputs and perform numerical simulations for nonorthogonal inputs. Moreover, in contrast to BCM, we show that triplet STDP can also induce selectivity for input patterns consisting of higher-order spatiotemporal correlations, which exist in natural stimuli and have been measured in the brain. We show that this sensitivity to higher-order correlations can be used to develop direction and speed selectivity.

POST-PROJECT ASSESSMENT OF PIT LATRINES IN RURAL PANAMA

In Panama, one of the Environmental Health (EH) Sector’s primary goals is to improve the health of rural Panamanians by helping them to adopt behaviors and practices that improve access to and use of sanitation systems. In complying with this goal, the EH sector has used participatory development models to improve hygiene and increase access to latrines through volunteer managed latrine construction projects. Unfortunately, there is little understanding of the long term sustainability of these interventions after the volunteers have completed their service. With the Peace Corps adapting their Monitoring, Reporting, and Evaluation procedures, it is appropriate to evaluate the sustainability of sanitation interventions offering recommendations for the adaptions of the EH training program, project management, and evaluation procedures. Recognizing the need for evaluation of past latrine projects, the author performed a post project assessment of 19 pit latrine projects using participatory analysis methodologies. First, the author reviewed volunteers’ perspectives of pit latrine projects in a survey. Then, for comparison, the author performed a survey of latrine projects using a benchmarking scoring system to rate solid waste management, drainage, latrine siting, latrine condition, and hygiene. It was observed that the Sanitation WASH matrix created by the author was an effective tool for evaluating the efficacy of sanitation interventions. Overall more than 75%, of latrines constructed were in use. However, there were some areas where improvements could be made for both latrine construction and health and hygiene. The latrines scored poorly on the indicators related to the privacy structure and seat covers. Interestingly those are the two items least likely to be included in project subsidies. Furthermore, scores for hygiene-related indicators were low; particularly those related to hand washing and cleanliness of the kitchen, indicating potential for improvement in hygiene education. Based on these outcomes, the EH sector should consider including subsidies and standardized designs for privacy structures and seat covers for latrines. In addition, the universal adoption of contracts and/or deposits for project beneficiaries is expected to improve the completion of latrines. In order to address the low scores in the health and hygiene indicators, the EH sector should adapt volunteer training, in addition to standardizing health and hygiene intervention procedures. In doing so, the sector should mimic the Community Health Club model that has shown success in improving health and hygiene indicators, as well as use a training session plan format similar to those in the Water Committee Seminar manual. Finally, the sector should have an experienced volunteer dedicated to program oversight and post-project monitoring and evaluation.

Die Erziehung zu einer aktiven Bürgerschaft

Trying to give a definition of Citizenship Education is a challenging operation: it is characterized by a variety of meanings flowing from Civic Education (related to knowledge and practice about the system of laws, rules, conventions referring to a particular civil community) to Socio-political education (related to the awareness of being part of the system of cultural elements, values, traditions historically produced by the community itself). It would be not be correct identifying Citizenship Education only with elements of Civic Education, as it would restrict its range to formal level of rules and laws, rights and duties. Otherwise, limiting its understanding only on elements of Sociopolitical Education, would offer the risk of investing in cultural similarities, common roots, values homogeneity, that are strong in giving hold on identity, membership, participation, but so exposed to acts of fanaticism, exclusion of diversity, hostility towards minorities. Therefore, it is necessary to assume that Citizenship Education has to be established on problematic integration of the two presented perspectives, thus founding knowledge and practice about the rules of civil society on the system of values and cultural aspects that every single micro-community (and every single individual) recognizes to be source of the rules: a complex system of various elements made of homogeneity and inhomogeneity, similarities and differences in constant modification an dynamic intercommunication.

International horse movements and spread of equine diseases: Equine Infectious Anaemia and Glanders - two examples

International trade with horses is important and continuously increasing. Therefore the risk of spread of infectious diseases is permanently present. Within this context the worldwide situation of equine vector-borne diseases and of other diseases which are notifiable to the World Organisation of Animal Health (OIE), is described. Furthermore it provides estimates of the numbers of horse movements between these countries, as well as information on import requirements and preventive measures for reducing the risk of disease spread. According to TRACES (Trade Control and Expert System of the European Union) data from 2009 and 2010 81 horses per week were imported from North America into Europe, 42 horses per week from South America, 11 horses per week from the North of Africa and the African horse sichness free-zone of South Africa, 28 per week from the Middle East and the rest of Asia and approximately 4 horses per week from Australia / Oceania. Trade within the European Union resulted amongst others in the introduction of Equine Infectious Anaemia (EIA) from Roma- nia into other European countries. Another example is the suspected case of glanders which occurred after importation of horses from Leb- anon via France and Germany into Switzerland in July 2011.

Bird species recorded in an untrained observer survey (UOS) and an expert observer survey (EOS) in 2011 in SE Peru

To evaluate the potential of community-based bird surveys in the tropics, we compared the species richness and abundances of bird functional groups that would be detected by a basic untrained observer (untrained observer survey, UOS) to a comprehensive bird species list compiled by a professional bird guide, in a coffee agroforestry landscape in the Peruvian East Andean foothills and compared functional signatures to global functional signatures of tropical bird assemblages. The submitted data comprises the transect counts of the UOS, the comprehensive bird list, ecological data of the recorded birds and information regarding the conservation status of the recorded birds from the IUCN Red List.

New data on the specular reflectance of ores (VNIR: 400 - 1000 nm) and their significance for ore microscopy

This work is part of the project CAMEVA for the development of an expert system aimed at the automatic identification of ores [1, 2]. It relies on the measure of their reflectance values, R, on digital images. Software for calibration, acquisition and analysis of the multispectral data was designed by AITEMIN [3]; the research was also assessed by H.J. Bernhardt and E. Pirard [1].

Efficient local unfolding with ancestor stacks

The most successful unfolding rules used nowadays in the partial evaluation of logic programs are based on well quasi orders (wqo) applied over (covering) ancestors, i.e., a subsequence of the atoms selected during a derivation. Ancestor (sub)sequences are used to increase the specialization power of unfolding while still guaranteeing termination and also to reduce the number of atoms for which the wqo has to be checked. Unfortunately, maintaining the structure of the ancestor relation during unfolding introduces significant overhead. We propose an efficient, practical local unfolding rule based on the notion of covering ancestors which can be used in combination with a wqo and allows a stack-based implementation without losing any opportunities for specialization. Using our technique, certain non-leftmost unfoldings are allowed as long as local unfolding is performed, i.e., we cover depth-first strategies. To deal with practical programs, we propose assertion-based techniques which allow our approach to treat programs that include (Prolog) built-ins and external predicates in a very extensible manner, for the case of leftmost unfolding. Finally, we report on our mplementation of these techniques embedded in a practical partial evaluator, which shows that our techniques, in addition to dealing with practical programs, are also significantly more efficient in time and somewhat more efficient in memory than traditional tree-based implementations. To appear in Theory and Practice of Logic Programming (TPLP).

An architectural model for software testing lesson learned systems

Software testing is a key aspect of software reliability and quality assurance in a context where software development constantly has to overcome mammoth challenges in a continuously changing environment. One of the characteristics of software testing is that it has a large intellectual capital component and can thus benefit from the use of the experience gained from past projects. Software testing can, then, potentially benefit from solutions provided by the knowledge management discipline. There are in fact a number of proposals concerning effective knowledge management related to several software engineering processes. Objective: We defend the use of a lesson learned system for software testing. The reason is that such a system is an effective knowledge management resource enabling testers and managers to take advantage of the experience locked away in the brains of the testers. To do this, the experience has to be gathered, disseminated and reused. Method: After analyzing the proposals for managing software testing experience, significant weaknesses have been detected in the current systems of this type. The architectural model proposed here for lesson learned systems is designed to try to avoid these weaknesses. This model (i) defines the structure of the software testing lessons learned; (ii) sets up procedures for lesson learned management; and (iii) supports the design of software tools to manage the lessons learned. Results: A different approach, based on the management of the lessons learned that software testing engineers gather from everyday experience, with two basic goals: usefulness and applicability. Conclusion: The architectural model proposed here lays the groundwork to overcome the obstacles to sharing and reusing experience gained in the software testing and test management. As such, it provides guidance for developing software testing lesson learned systems.

Automating HAZOP studies using D-higraphs

In this paper, we present the use of D-higraphs to perform HAZOP studies. D-higraphs is a formalism that includes in a single model the functional as well as the structural (ontological) components of any given system. A tool to perform a semi-automatic guided HAZOP study on a process plant is presented. The diagnostic system uses an expert system to predict the behavior modeled using D-higraphs. This work is applied to the study of an industrial case and its results are compared with other similar approaches proposed in previous studies. The analysis shows that the proposed methodology fits its purpose enabling causal reasoning that explains causes and consequences derived from deviations, it also fills some of the gaps and drawbacks existing in previous reported HAZOP assistant tools.

Sistema de Aparcamiento Inteligente Aplicado a las Smart Cities

En las últimas décadas el mundo ha sufrido un aumento exponencial en la utilización de soluciones tecnológicas, lo que ha desembocado en la necesidad de medir situaciones o estados de los distintos objetos que nos rodean. A menudo, no es posible cablear determinados sensores por lo que ese aumento en la utilización de soluciones tecnológicas, se ha visto traducido en un aumento de la necesidad de utilización de sensórica sin cables para poder hacer telemetrías correctas. A nivel social, el aumento de la demografía mundial está estrechamente ligado al aumento de la necesidad de servicios tecnológicos, por lo que es lógico pensar que a más habitantes, más tecnología será consumida. El objetivo de este Proyecto Final de Carrera está basado en la utilización de diversos nodos o también llamados motas capaces de realizar transferencia de datos en modo sin cables, permitiendo así realizar una aplicación real que solvente problemas generados por el aumento de la densidad de población. En concreto se busca la realización de un sistema de aparcamiento inteligente para estacionamientos en superficie, ayudando por tanto a las tareas de ordenación vehicular dentro del marco de las Smart cities. El sistema está basado en el protocolo de comunicaciones 802.15.4 (ZigBee) cuyas características fundamentales radican en el bajo consumo de energía de los componentes hardware asociados. En primer lugar se realizará un Estado del Arte de las Redes Inalámbricas de Sensores, abordando tanto la arquitectura como el estándar Zigbee y finalmente los componentes XBee que se van a utilizar en este Proyecto. Seguidamente se realizará la algoritmia necesaria para el buen funcionamiento del sistema inteligente de estacionamiento y finalmente se realizará un piloto demostrador del correcto funcionamiento de la tecnología. ABSTRACT In the last decades the world has experienced an exponential increase in the use of technological solutions, which has resulted in the need to measure situations or states of the objects around us. Often, wired sensors cannot be used at many situations, so the increase in the use of technological solutions, has been translated into a increase of the need of using wireless sensors to make correct telemetries. At the social level, the increase in global demographics is closely linked to the increased need for technological services, so it is logical that more people, more technology will be consumed. The objective of this Final Project is based on the use of various nodes or so-called motes, capable of performing data transfer in wireless mode, thereby allowing performing a real application solving problems generated by the increase of population densities. Specifically looking for the realization of a smart outdoor parking system, thus helping to vehicular management tasks within the framework of the Smart Cities. The system is based on the communication protocol 802.15.4 (ZigBee) whose main characteristics lie in the low energy consumption associated to the hardware components. First there will be a State of the Art of Wireless Sensor Networks, addressing both architecture and finally the Zigbee standard XBee components to be used in this project. Then the necessary algorithms will be developed for the proper working of the intelligent parking system and finally there will be a pilot demonstrator validating the whole system.

Instalación de un sistema funcional sobre un computador convencional

En esta tesis se tratan dos aspectos fundamentales de los sistemas funcionales, de cuyo tratamiento depende, en gran medida, la eficiencia de tales sistemas. En primer lugar, se presentan y evalúan una serie de soluciones al problema de representación interna en los sistemas funcionales, soluciones basadas en la utilización de estructuras lineales para obtener una mejora en el tiempo de ejecución y en la ocupación de la memoria del sistema. En segundo lugar, se presenta un sistema de evaluación multitarea para reducir programas funcionales, basado en la especificación de varios ficheros de salida. En él, las tareas del sistema evalúan, de forma concurrente, las diversas partes del resultado de un programa y se .comunican entre sí en base a mensajes que permiten detectar y resolver, sin necesidad de abortar la ejecución, bucles de dependencias entre tareas. El sistema reacciona ante estas situaciones de error de forma comedida, de modo que este error no afecta al resto de las tareas del sistema. Se plantea también un mecanismo de gestión de memoria, mecanismo que introduce una tarea especial en el sistema, encargada de la gestión de una memoria común a todo él, y satisface las necesidades de memoria de las tareas de forma, transparente al mecanismo de evaluación.---ABSTRACT---Two fundamental aspects of functional systems, of which their efficiency to a large extent depends, are dealt with in this thesis. Firstly, several solutions to the internal representation problem of functional systems are proposed and evaluated. These solutions are based on the use of linear data structures in order to achieve a shorter execution time and smaller memory requirement. Secondly, a new multitask evaluation system for the reduction of functional programs is described; it is based on the specifücation of several output files. In this evaluation system, the task evaluates in the different parts of the program result concurrently. Tasks communicate one another through messages, which make it possible to detect and solve the dependency loops within tasks. The program does not need to be aborted, the sistem reacts to such error situations in a smooth way, no other tasks are affected. A memory management system is also introduced. This management system inserts a special task, that carries-out the management of a common memory and serves all tasks memory requirements in a transparent mode to the evaluation mechanism.

New agri-environmental policies for the sustainability of mountainous olive farming. Evidences from Andalusia, Spain

La sostenibilidad de los sistemas olivareros situados en zonas de pendiente y montaña (SMOPS) en Andalucía se encuentra actualmente amenazada por las elevadas tasas de abandono que afectan a estos sistemas productivos. Así, la consumación de este proceso de abandono, no sólo pondría en peligro a las propias explotaciones, sino a todo el conjunto de bienes y servicios no productivos y al patrimonio cultural generado por este sistema productivo. En este contexto, la búsqueda de alternativas políticas enfocadas a revertir este proceso se erige como una necesidad categórica en aras de garantizar en el largo plazo la sostenibilidad de los olivares de montaña. Esta tesis pretende hacer frente a esta necesidad a través de la construcción de un marco político alternativo para los SMOPS, que permita la integración simultánea de todas las dimensiones que pueden influir en su desarrollo; esto es: el marco político actual, principalmente determinado por la Política Agraria Común (PAC) de la Unión Europea (UE); las preferencias de la sociedad hacia la oferta de bienes y servicios públicos generados por los SMOPS; y las preferencias y voluntad de innovación hacia nuevos manejos y sistemas de gestión de los agricultores y propietarios de las explotaciones. Para ello, se emplea una metodología de investigación mixta, que abarca la realización de cuatro encuestas (personales y online) llevadas a cabo a los agentes o grupos de interés involucrados directa o indirectamente en la gestión de los SMOPS –ciudadanos, agricultores y propietarios y expertos-; una profunda revisión de las herramientas de política agroambiental actuales y posibles alternativas a las mismas; y el desarrollo de nuevas estrategias metodológicas para dotar de mayor precisión y fiabilidad las estimaciones obtenidas a partir del Método del Experimento de Elección (MEE) en el campo de la valoración medioambiental. En general, los resultados muestran que una estrategia de política agroambiental basada en la combinación de los Contratos Territoriales de Zona Rural (CTZR) y el manejo ecológico supondría una mejora en la sostenibilidad de los sistemas olivareros de montaña andaluces, que, al mismo tiempo, propiciaría una mejor consideración de las necesidades y demandas de los agentes implicados en su gestión. Asimismo, los hallazgos obtenidos en esta investigación demandan un cambio de paradigma en los actuales pagos agroambientales, que han de pasar de una estrategia basada en la implementación de acciones, a otra enfocada al logro de objetivos, la cual, en el caso del olivar, se podría centrar en el aumento del secuestro de carbono en el suelo. Desde un punto de vista metodológico, los resultados han contribuido notablemente a mejorar la fiabilidad y precisión de las conclusiones estimadas a partir del MEE, mediante el diseño de un novedoso proceso iterativo para detectar posibles comportamientos inconsistentes por parte de los entrevistados con respecto a su máxima Disposición al Pago (DAP) para lograr la situación considerada como “óptima” en los olivares ecológicos de montaña andaluces. En líneas generales, el actual marco institucional favorece la puesta en práctica de la mayoría de las estrategias propuestas en esta tesis; sin embargo son necesarios mayores esfuerzos para reconducir los actuales Pagos Agroambientales y Climáticos de la PAC, hacia una estrategia de política agroambiental adaptada a las necesidades y requisitos del territorio en el que se aplica, enfocada al logro de objetivos y que sea capaz de integrar y coordinar al conjunto de agentes y grupos de interés involucrados -directa o indirectamente- en la gestión de los olivares de montaña. En este contexto, se espera que la puesta en práctica de nuevas estructuras y acuerdos de gobernanza territorial juegue un importante papel en el desarrollo de una política agroambiental realmente adaptada a las necesidades de los sistemas olivareros de montaña andaluces. ABSTRACT The long-term sustainability of Andalusian sloping and mountainous olive production systems (SMOPS) is currently threatened by the high abandonment rates that affect these production systems. The effective occurrence of this abandonment process is indeed menacing not only farms themselves, but also the wide array of public goods and services provided by SMOPS and the cultural heritage held by this production system. The search of policy alternatives aimed at tackling this process is thus a central necessity. This thesis aims to undertake this necessity by building an alternative policy framework for SMOPS that simultaneously integrates the several dimensions that are susceptible to influence it, namely: the current policy framework, mainly determined by the European Union’s (EU) Common Agricultural Policy (CAP); the social preferences toward the supply of SMOPS’ public goods and services; and farmers’ preferences and willingness to innovate toward new management practices in their farms. For this purpose, we put into practice a mixed-method strategy that combines four face-to-face and online surveys carried out with SMOPS’ stakeholders -including citizens, farmers and experts-; in-depth analysis of current and alternative agrienvironmental policy (AEP) instruments; and the development of novel methodological approaches to advance toward more reliable Discrete Choice Experiment’s (DCE) outcomes in the field of environmental valuation. Overall, results show that a policy strategy based on the combination of Territorial Management Contracts (TMC) and organic management would further enhance Andalusian SMOPS’ sustainability by simultaneously taking into account stakeholders’ demands and needs. Findings also call for paradigm shift of the current action-oriented design of Agri-Environmental-Climate Schemes (AECS), toward a result-based approach, that in the case of olive orchards should particularly be focused on enhancing soil carbon sequestration. From a methodological perspective, results have contributed to improve the accuracy and feasibility of DCE outcomes by designing a novel and iterative procedure focused in ascertaining respondents’ inconsistent behaviour with respect to their stated maximum WTP for the attainment of an ideal situation to be achieved in organic Andalusian SMOPS. Generally, the present institutional framework favours the implementation of the main policy strategies proposed in this thesis, albeit further efforts are required to better conduct current CAP’s agri-environmental instruments toward a territorially targeted result-oriented strategy capable to integrate and coordinate the whole set of stakeholders involved in the management of SMOPS. In this regard, alternative governance structures and arrangements are expected to play a major role on the process of tackling SMOPS’ agri-environmental policy challenge.

Optimización multiobjetivo inteligente del dimensionamiento energético en sistemas ferroviarios señalizados y en plataformas software de tiempo real

La capacidad de transporte es uno de los baremos fundamentales para evaluar la progresión que puede llegar a tener un área económica y social. Es un sector de elevada importancia para la sociedad actual. Englobado en los distintos tipos de transporte, uno de los medios de transporte que se encuentra más en alza en la actualidad, es el ferroviario. Tanto para movilidad de pasajeros como para mercancías, el tren se ha convertido en un medio de transporte muy útil. Se encuentra dentro de las ciudades, entre ciudades con un radio pequeño entre ellas e incluso cada vez más, gracias a la alta velocidad, entre ciudades con gran distancia entre ellas. Esta Tesis pretende ayudar en el diseño de una de las etapas más importantes de los Proyectos de instalación de un sistema ferroviario: el sistema eléctrico de tracción. La fase de diseño de un sistema eléctrico de tracción ferroviaria se enfrenta a muchas dudas que deben ser resueltas con precisión. Del éxito de esta fase dependerá la capacidad de afrontar las demandas de energía de la explotación ferroviaria. También se debe atender a los costes de instalación y de operación, tanto costes directos como indirectos. Con la Metodología que se presenta en esta Tesis se ofrecerá al diseñador la opción de manejar un sistema experto que como soluciones le plantee un conjunto de escenarios de sistemas eléctricos correctos, comprobados por resolución de modelos de ecuaciones. Correctos desde el punto de vista de validez de distintos parámetros eléctrico, como de costes presupuestarios e impacto de costes indirectos. Por tanto, el diseñador al haber hecho uso de esta Metodología, tendría en un espacio de tiempo relativamente corto, un conjunto de soluciones factibles con las que poder elegir cuál convendría más según sus intereses finales. Esta Tesis se ha desarrollado en una vía de investigación integrada dentro del Centro de Investigaciones Ferroviarias CITEF-UPM. Entre otros proyectos y vías de investigación, en CITEF se ha venido trabajando en estudios de validación y dimensionamiento de sistemas eléctricos ferroviarios con diversos y variados clientes y sistemas ferroviarios. A lo largo de los proyectos realizados, el interés siempre ha girado mayoritariamente sobre los siguientes parámetros del sistema eléctrico: - Calcular número y posición de subestaciones de tracción. Potencia de cada subestación. - Tipo de catenaria a lo largo del recorrido. Conductores que componen la catenaria. Características. - Calcular número y posición de autotransformadores para sistemas funcionando en alterna bitensión o 2x25kV. - Posición Zonas Neutras. - Validación según normativa de: o Caídas de tensión en la línea o Tensiones máximas en el retorno de la línea o Sobrecalentamiento de conductores o Sobrecalentamiento de los transformadores de las subestaciones de tracción La idea es que las soluciones aportadas por la Metodología sugieran escenarios donde de estos parámetros estén dentro de los límites que marca la normativa. Tener la posibilidad de tener un repositorio de posibles escenarios donde los parámetros y elementos eléctricos estén calculados como correctos, aporta un avance en tiempos y en pruebas, que mejoraría ostensiblemente el proceso habitual de diseño para los sistemas eléctricos ferroviarios. Los costes directos referidos a elementos como subestaciones de tracción, autotransformadores, zonas neutras, ocupan un gran volumen dentro del presupuesto de un sistema ferroviario. En esta Tesis se ha querido profundizar también en el efecto de los costes indirectos provocados en la instalación y operación de sistemas eléctricos. Aquellos derivados del impacto medioambiental, los costes que se generan al mantener los equipos eléctricos y la instalación de la catenaria, los costes que implican la conexión entre las subestaciones de tracción con la red general o de distribución y por último, los costes de instalación propios de cada elemento compondrían los costes indirectos que, según experiencia, se han pensado relevantes para ejercer un cierto control sobre ellos. La Metodología cubrirá la posibilidad de que los diseños eléctricos propuestos tengan en cuenta variaciones de coste inasumibles o directamente, proponer en igualdad de condiciones de parámetros eléctricos, los más baratos en función de los costes comentados. Analizando los costes directos e indirectos, se ha pensado dividir su impacto entre los que se computan en la instalación y los que suceden posteriormente, durante la operación de la línea ferroviaria. Estos costes normalmente suelen ser contrapuestos, cuánto mejor es uno peor suele ser el otro y viceversa, por lo que hace falta un sistema que trate ambos objetivos por separado. Para conseguir los objetivos comentados, se ha construido la Metodología sobre tres pilares básicos: - Simulador ferroviario Hamlet: Este simulador integra módulos para construir esquemas de vías ferroviarios completos; módulo de simulación mecánica y de la tracción de material rodante; módulo de señalización ferroviaria; módulo de sistema eléctrico. Software realizado en C++ y Matlab. - Análisis y estudio de cómo focalizar los distintos posibles escenarios eléctricos, para que puedan ser examinados rápidamente. Pico de demanda máxima de potencia por el tráfico ferroviario. - Algoritmos de optimización: A partir de un estudio de los posibles algoritmos adaptables a un sistema tan complejo como el que se plantea, se decidió que los algoritmos genéticos serían los elegidos. Se han escogido 3 algoritmos genéticos, permitiendo recabar información acerca del comportamiento y resultados de cada uno de ellos. Los elegidos por motivos de tiempos de respuesta, multiobjetividad, facilidad de adaptación y buena y amplia aplicación en proyectos de ingeniería fueron: NSGA-II, AMGA-II y ɛ-MOEA. - Diseño de funciones y modelo preparado para trabajar con los costes directos e indirectos y las restricciones básicas que los escenarios eléctricos no deberían violar. Estas restricciones vigilan el comportamiento eléctrico y la estabilidad presupuestaria. Las pruebas realizadas utilizando el sistema han tratado o bien de copiar situaciones que se puedan dar en la realidad o directamente sistemas y problemas reales. Esto ha proporcionado además de la posibilidad de validar la Metodología, también se ha posibilitado la comparación entre los algoritmos genéticos, comparar sistemas eléctricos escogidos con los reales y llegar a conclusiones muy satisfactorias. La Metodología sugiere una vía de trabajo muy interesante, tanto por los resultados ya obtenidos como por las oportunidades que puede llegar a crear con la evolución de la misma. Esta Tesis se ha desarrollado con esta idea, por lo que se espera pueda servir como otro factor para trabajar con la validación y diseño de sistemas eléctricos ferroviarios. ABSTRACT Transport capacity is one of the critical points to evaluate the progress than a specific social and economical area is able to reach. This is a sector of high significance for the actual society. Included inside the most common types of transport, one of the means of transport which is elevating its use nowadays is the railway. Such as for passenger transport of weight movements, the train is being consolidated like a very useful mean of transport. Railways are installed in many geography areas. Everyone know train in cities, or connecting cities inside a surrounding area or even more often, taking into account the high-speed, there are railways infrastructure between cities separated with a long distance. This Ph.D work aims to help in the process to design one of the most essential steps in Installation Projects belonging to a railway system: Power Supply System. Design step of the railway power supply, usually confronts to several doubts and uncertainties, which must be solved with high accuracy. Capacity to supply power to the railway traffic depends on the success of this step. On the other hand is very important to manage the direct and indirect costs derived from Installation and Operation. With the Methodology is presented in this Thesis, it will be offered to the designer the possibility to handle an expert system that finally will fill a set of possible solutions. These solutions must be ready to work properly in the railway system, and they were tested using complex equation models. This Thesis has been developed through a research way, integrated inside Citef (Railway Research Centre of Technical University of Madrid). Among other projects and research ways, in Citef has been working in several validation studies and dimensioning of railway power supplies. It is been working by a large range of clients and railways systems. Along the accomplished Projects, the main goal has been rounded mostly about the next list of parameters of the electrical system: - Calculating number and location of traction substations. Power of each substation. - Type of Overhead contact line or catenary through the railway line. The wires which set up the catenary. Main Characteristics. - Calculating number and position of autotransformers for systems working in alternating current bi-voltage of called 2x25 kV. - Location of Neutral Zones. - Validating upon regulation of: o Drop voltages along the line o Maximum return voltages in the line o Overheating/overcurrent of the wires of the catenary o Avoiding overheating in the transformers of the traction substations. Main objective is that the solutions given by the Methodology, could be suggest scenarios where all of these parameters from above, would be between the limits established in the regulation. Having the choice to achieve a repository of possible good scenarios, where the parameters and electrical elements will be assigned like ready to work, that gives a great advance in terms of times and avoiding several tests. All of this would improve evidently the regular railway electrical systems process design. Direct costs referred to elements like traction substations, autotransformers, neutral zones, usually take up a great volume inside the general budget in railway systems. In this Thesis has been thought to bear in mind another kind of costs related to railway systems, also called indirect costs. These could be enveloped by those enmarked during installation and operation of electrical systems. Those derived from environmental impact; costs generated during the maintenance of the electrical elements and catenary; costs involved in the connection between traction substations and general electric grid; finally costs linked with the own installation of the whole electrical elements needed for the correct performance of the railway system. These are integrated inside the set has been collected taking into account own experience and research works. They are relevant to be controlled for our Methodology, just in case for the designers of this type of systems. The Methodology will cover the possibility that the final proposed power supply systems will be hold non-acceptable variations of costs, comparing with initial expected budgets, or directly assuming a threshold of budget for electrical elements in actual scenario, and achieving the cheapest in terms of commented costs from above. Analyzing direct and indirect costs, has been thought to divide their impact between two main categories. First one will be inside the Installation and the other category will comply with the costs often happens during Railway Operation time. These costs normally are opposed, that means when one is better the other turn into worse, in costs meaning. For this reason is necessary treating both objectives separately, in order to evaluate correctly the impact of each one into the final system. The objectives detailed before build the Methodology under three basic pillars: - Railway simulator Hamlet: This software has modules to configure many railway type of lines; mechanical and traction module to simulate the movement of rolling stock; signaling module; power supply module. This software has been developed using C++ and Matlab R13a - Previously has been mandatory to study how would be possible to work properly with a great number of feasible electrical systems. The target comprised the quick examination of these set of scenarios in terms of time. This point is talking about Maximum power demand peaks by railway operation plans. - Optimization algorithms. A railway infrastructure is a very complex system. At the beginning it was necessary to search about techniques and optimization algorithms, which could be adaptable to this complex system. Finally three genetic multiobjective algorithms were the chosen. Final decision was taken attending to reasons such as time complexity, able to multiobjective, easy to integrate in our problem and with a large application in engineering tasks. They are: NSGA-II, AMGA-II and ɛ-MOEA. - Designing objectives functions and equation model ready to work with the direct and indirect costs. The basic restrictions are not able to avoid, like budgetary or electrical, connected hardly with the recommended performance of elements, catenary and safety in a electrical railway systems. The battery of tests launched to the Methodology has been designed to be as real as possible. In fact, due to our work in Citef and with real Projects, has been integrated and configured three real railway lines, in order to evaluate correctly the final results collected by the Methodology. Another topic of our tests has been the comparison between the performances of the three algorithms chosen. Final step has been the comparison again with different possible good solutions, it means power supply system designs, provided by the Methodology, testing the validity of them. Once this work has been finished, the conclusions have been very satisfactory. Therefore this Thesis suggest a very interesting way of research and work, in terms of the results obtained and for the future opportunities can be created with the evolution of this. This Thesis has been developed with this idea in mind, so is expected this work could adhere another factor to work in the difficult task of validation and design of railway power supply systems.