Analysis of The Key Parameters in Pedestrian Safety Assessment for the European Vehicle Fleet Using Multibody and Finite Element Mathematical Models

Esta tesis investiga cuales son los parámetros más críticos que condicionan los resultados que obtienen en los ensayos de protección de peatones la flota Europea de vehículos, según la reglamentación europea de protección de peatones de 2003 (Directiva CE 2003/102) y el posterior Reglamento de 2009 (Reglamento CE 2009/78). En primer lugar se ha analizado el contexto de la protección de peatones en Europa, viendo la historia de las diferentes propuestas de procedimientos de ensayo así como los cambios (y las razones de los mismos) que han sufrido a lo largo del proceso de definición de la normativa Europea. Con la información disponible de más de 400 de estos ensayos se han desarrollado corredores de rigidez para los frontales de los diferentes segmentos de la flota de vehículos europea, siendo este uno de los resultados más relevantes de esta tesis. Posteriormente, esta tesis ha realizado un estudio accidentológico en detalle de los escenarios de atropello de peatones, identificando sus características más relevantes, los grupos de población con mayor riesgo y los tipos de lesiones más importantes que aparecen (en frecuencia y severidad), que han sentado las bases para analizar con modelos matemáticos hasta qué punto los métodos de ensayo propuestos realmente tienen estos factores en cuenta. Estos análisis no habrían sido posibles sin el desarrollo de las nuevas herramientas que se presentan en esta tesis, que permiten construir instantáneamente el modelo matemático de cualquier vehículo y cualquier peatón adulto para analizar su iteración. Así, esta tesis ha desarrollado una metodología rápida para desarrollar modelos matemáticos de vehículos a demanda, de cualquier marca y modelo y con las características geométricas y de rigidez deseados que permitan representarlo matemáticamente y del mismo modo, ha investigado cómo evoluciona el comportamiento del cuerpo humano durante el envejecimiento y ha implementado una funcionalidad de escalado en edad al modelo de peatón en multicuerpo de MADYMO (ya escalable en tamaño) para permitir modelar ad hoc cualquier peatón adulto (en género y edad). Finalmente, esta tesis también ha realizado, utilizando modelos de elementos finitos del cuerpo humano, diferentes estudios sobre la biomecánica de las lesiones más frecuentes de este tipo de accidentes, (en piernas y cabeza) con el objetivo de mejorar los procedimientos de ensayo para que predigan mejor el tipo de lesiones que se quieren evitar. Con el marco temporal y las condiciones de contorno de esta tesis se han centrado los esfuerzos en reforzar algunos aspectos críticos pero puntuales sobre cómo mejorar el ensayo de cabeza y, sobretodo, en proponer soluciones viables y con un valor añadido real al ensayo de pierna contra parachoques, sin cambiar la esencia del mismo pero proponiendo un nuevo impactador mejorado que incorpore una masa extra que representa a la parte superior del cuerpo y sea válido para toda la flota europea de vehículos independiente de la geometría de su frontal.

Mathematical models for the arrangement and the cleaning of the river basin and surroundings of the river sandy grounds to its passage by the city of Salta (Argentina)

The province of Salta is located the Northwest of Argentina in the border with Bolivia, Chile and Paraguay. Its Capital is the city of Salta that concentrates half of the inhabitants of the province and has grown to 600000 hab., from a small active Spanish town well founded in 1583. The city is crossed by the Arenales River descending from close mountains at North, source of water and end of sewers. But with actual growing it has become a focus of infection and of remarkable unhealthiness. It is necessary to undertake a plan for the recovery of the river, directed to the attainment of the well-being and to improve the life?s quality of the Community. The fundamental idea of the plan is to obtain an ordering of the river basin and an integral management of the channel and its surroundings, including the cleaning out. The improvement of the water?s quality, the healthiness of the surroundings and the improvement of the environment, must go hand by hand with the development of sport activities, of relaxation, tourism, establishment of breeding grounds, kitchen gardens, micro enterprises with clean production and other actions that contribute to their benefit by the society, that being a basic factor for their care and sustainable use. The present pollution is organic, chemical, industrial, domestic, due to the disposition of sweepings and sewer effluents that affects not only the flora and small fauna, destroying the biodiversity, but also to the health of people living in their margins. Within the plan it will be necessary to consider, besides hydric and environmental cleaning and the prevention of floods, the planning of the extraction of aggregates, the infrastructure and consolidation of margins works and the arrangement of all the river basin. It will be necessary to consider the public intervention at state, provincial and local level, and the private intervention. In the model it has been necessary to include the sub-model corresponding to the election of the entity to be the optimal instrument to reach the proposed objectives, giving an answer to the social, environmental and economic requirements. For that the authors have used multi-criteria decision methods to qualify and select alternatives, and for the programming of their implementation. In the model the authors have contemplated the short, average and long term actions. They conform a Paretooptimal alternative which secures the ordering, integral and suitable management of the basin of the Arenales River, focusing on its passage by the city of Salta.

Oscillatory genetic circuits: new designs and mathematical models

Introduction and motivation: A wide variety of organisms have developed in-ternal biomolecular clocks in order to adapt to cyclic changes of the environment. Clock operation involves genetic networks. These genetic networks have to be mod¬eled in order to understand the underlying mechanism of oscillations and to design new synthetic cellular clocks. This doctoral thesis has resulted in two contributions to the fields of genetic clocks and systems and synthetic biology, generally. The first contribution is a new genetic circuit model that exhibits an oscillatory behav¬ior through catalytic RNA molecules. The second and major contribution is a new genetic circuit model demonstrating that a repressor molecule acting on the positive feedback of a self-activating gene produces reliable oscillations. First contribution: A new model of a synthetic genetic oscillator based on a typical two-gene motif with one positive and one negative feedback loop is pre¬sented. The originality is that the repressor is a catalytic RNA molecule rather than a protein or a non-catalytic RNA molecule. This catalytic RNA is a ribozyme that acts post-transcriptionally by binding to and cleaving target mRNA molecules. This genetic clock involves just two genes, a mRNA and an activator protein, apart from the ribozyme. Parameter values that produce a circadian period in both determin¬istic and stochastic simulations have been chosen as an example of clock operation. The effects of the stochastic fluctuations are quantified by a period histogram and autocorrelation function. The conclusion is that catalytic RNA molecules can act as repressor proteins and simplify the design of genetic oscillators. Second and major contribution: It is demonstrated that a self-activating gene in conjunction with a simple negative interaction can easily produce robust matically validated. This model is comprised of two clearly distinct parts. The first is a positive feedback created by a protein that binds to the promoter of its own gene and activates the transcription. The second is a negative interaction in which a repressor molecule prevents this protein from binding to its promoter. A stochastic study shows that the system is robust to noise. A deterministic study identifies that the oscillator dynamics are mainly driven by two types of biomolecules: the protein, and the complex formed by the repressor and this protein. The main conclusion of this study is that a simple and usual negative interaction, such as degradation, se¬questration or inhibition, acting on the positive transcriptional feedback of a single gene is a sufficient condition to produce reliable oscillations. One gene is enough and the positive transcriptional feedback signal does not need to activate a second repressor gene. At the genetic level, this means that an explicit negative feedback loop is not necessary. Unlike many genetic oscillators, this model needs neither cooperative binding reactions nor the formation of protein multimers. Applications and future research directions: Recently, RNA molecules have been found to play many new catalytic roles. The first oscillatory genetic model proposed in this thesis uses ribozymes as repressor molecules. This could provide new synthetic biology design principles and a better understanding of cel¬lular clocks regulated by RNA molecules. The second genetic model proposed here involves only a repression acting on a self-activating gene and produces robust oscil¬lations. Unlike current two-gene oscillators, this model surprisingly does not require a second repressor gene. This result could help to clarify the design principles of cellular clocks and constitute a new efficient tool for engineering synthetic genetic oscillators. Possible follow-on research directions are: validate models in vivo and in vitro, research the potential of second model as a genetic memory, investigate new genetic oscillators regulated by non-coding RNAs and design a biosensor of positive feedbacks in genetic networks based on the operation of the second model Resumen Introduccion y motivacion: Una amplia variedad de organismos han desarro-llado relojes biomoleculares internos con el fin de adaptarse a los cambios ciclicos del entorno. El funcionamiento de estos relojes involucra redes geneticas. El mo delado de estas redes geneticas es esencial tanto para entender los mecanismos que producen las oscilaciones como para diseiiar nuevos circuitos sinteticos en celulas. Esta tesis doctoral ha dado lugar a dos contribuciones dentro de los campos de los circuitos geneticos en particular, y biologia de sistemas y sintetica en general. La primera contribucion es un nuevo modelo de circuito genetico que muestra un comportamiento oscilatorio usando moleculas de ARN cataliticas. La segunda y principal contribucion es un nuevo modelo de circuito genetico que demuestra que una molecula represora actuando sobre el lazo de un gen auto-activado produce oscilaciones robustas. Primera contribucion: Es un nuevo modelo de oscilador genetico sintetico basado en una tipica red genetica compuesta por dos genes con dos lazos de retroa-limentacion, uno positivo y otro negativo. La novedad de este modelo es que el represor es una molecula de ARN catalftica, en lugar de una protefna o una molecula de ARN no-catalitica. Este ARN catalitico es una ribozima que actua despues de la transcription genetica uniendose y cortando moleculas de ARN mensajero (ARNm). Este reloj genetico involucra solo dos genes, un ARNm y una proteina activadora, aparte de la ribozima. Como ejemplo de funcionamiento, se han escogido valores de los parametros que producen oscilaciones con periodo circadiano (24 horas) tanto en simulaciones deterministas como estocasticas. El efecto de las fluctuaciones es-tocasticas ha sido cuantificado mediante un histograma del periodo y la función de auto-correlacion. La conclusion es que las moleculas de ARN con propiedades cataliticas pueden jugar el misnio papel que las protemas represoras, y por lo tanto, simplificar el diseno de los osciladores geneticos. Segunda y principal contribucion: Es un nuevo modelo de oscilador genetico que demuestra que un gen auto-activado junto con una simple interaction negativa puede producir oscilaciones robustas. Este modelo ha sido estudiado y validado matematicamente. El modelo esta compuesto de dos partes bien diferenciadas. La primera parte es un lazo de retroalimentacion positiva creado por una proteina que se une al promotor de su propio gen activando la transcription. La segunda parte es una interaction negativa en la que una molecula represora evita la union de la proteina con el promotor. Un estudio estocastico muestra que el sistema es robusto al ruido. Un estudio determinista muestra que la dinamica del sistema es debida principalmente a dos tipos de biomoleculas: la proteina, y el complejo formado por el represor y esta proteina. La conclusion principal de este estudio es que una simple y usual interaction negativa, tal como una degradation, un secuestro o una inhibition, actuando sobre el lazo de retroalimentacion positiva de un solo gen es una condition suficiente para producir oscilaciones robustas. Un gen es suficiente y el lazo de retroalimentacion positiva no necesita activar a un segundo gen represor, tal y como ocurre en los relojes actuales con dos genes. Esto significa que a nivel genetico un lazo de retroalimentacion negativa no es necesario de forma explicita. Ademas, este modelo no necesita reacciones cooperativas ni la formation de multimeros proteicos, al contrario que en muchos osciladores geneticos. Aplicaciones y futuras lineas de investigacion: En los liltimos anos, se han descubierto muchas moleculas de ARN con capacidad catalitica. El primer modelo de oscilador genetico propuesto en esta tesis usa ribozimas como moleculas repre¬soras. Esto podria proporcionar nuevos principios de diseno en biologia sintetica y una mejor comprension de los relojes celulares regulados por moleculas de ARN. El segundo modelo de oscilador genetico propuesto aqui involucra solo una represion actuando sobre un gen auto-activado y produce oscilaciones robustas. Sorprendente-mente, un segundo gen represor no es necesario al contrario que en los bien conocidos osciladores con dos genes. Este resultado podria ayudar a clarificar los principios de diseno de los relojes celulares naturales y constituir una nueva y eficiente he-rramienta para crear osciladores geneticos sinteticos. Algunas de las futuras lineas de investigation abiertas tras esta tesis son: (1) la validation in vivo e in vitro de ambos modelos, (2) el estudio del potential del segundo modelo como circuito base para la construction de una memoria genetica, (3) el estudio de nuevos osciladores geneticos regulados por ARN no codificante y, por ultimo, (4) el rediseno del se¬gundo modelo de oscilador genetico para su uso como biosensor capaz de detectar genes auto-activados en redes geneticas.

The Learning of the Mathematical Models to Aid Decision Making in the High Level Engineering Schools?

At present, in the University curricula in most countries, the decision theory and the mathematical models to aid decision making is not included, as in the graduate program like in Doctored and Master´s programs. In the Technical School of High Level Agronomic Engineers of the Technical University of Madrid (ETSIA-UPM), the need to offer to the future engineers training in a subject that could help them to take decisions in their profession was felt. Along the life, they will have to take a lot of decisions. Ones, will be important and others no. In the personal level, they will have to take several very important decisions, like the election of a career, professional work, or a couple, but in the professional field, the decision making is the main role of the Managers, Politicians and Leaders. They should be decision makers and will be paid for it. Therefore, nobody can understand that such a professional that is called to practice management responsibilities in the companies, does not take training in such an important matter. For it, in the year 2000, it was requested to the University Board to introduce in the curricula an optional qualified subject of the second cycle with 4,5 credits titled " Mathematical Methods for Making Decisions ". A program was elaborated, the didactic material prepared and programs as Maple, Lingo, Math Cad, etc. installed in several IT classrooms, where the course will be taught. In the course 2000-2001 this subject was offered with a great acceptance that exceeded the forecasts of capacity and had to be prepared more classrooms. This course in graduate program took place in the Department of Applied Mathematics to the Agronomic Engineering, as an extension of the credits dedicated to Mathematics in the career of Engineering.

Development of mathematical models to elaborate strategies, select alternatives and development of plans for adaptation of communities to climate change in different geographical areas including costs to implement it.

There is evidence that the climate changes and that now, the change is influenced and accelerated by the CO2 augmentation in atmosphere due to combustion by humans. Such ?Climate change? is on the policy agenda at the global level, with the aim of understanding and reducing its causes and to mitigate its consequences. In most countries and international organisms UNO (e.g. Rio de Janeiro 1992), OECD, EC, etc . . . the efforts and debates have been directed to know the possible causes, to predict the future evolution of some variable conditioners, and trying to make studies to fight against the effects or to delay the negative evolution of such. The Protocol of Kyoto 1997 set international efforts about CO2 emissions, but it was partial and not followed e.g. by USA and China . . . , and in Durban 2011 the ineffectiveness of humanity on such global real challenges was set as evident. Among all that, the elaboration of a global model was not boarded that can help to choose the best alternative between the feasible ones, to elaborate the strategies and to evaluate the costs, and the authors propose to enter in that frame for study. As in all natural, technological and social changes, the best-prepared countries will have the best bear and the more rapid recover. In all the geographic areas the alternative will not be the same one, but the model must help us to make the appropriated decision. It is essential to know those areas that are more sensitive to the negative effects of climate change, the parameters to take into account for its evaluation, and comprehensive plans to deal with it. The objective of this paper is to elaborate a mathematical model support of decisions, which will allow to develop and to evaluate alternatives of adaptation to the climatic change of different communities in Europe and Latin-America, mainly in especially vulnerable areas to the climatic change, considering in them all the intervening factors. The models will consider criteria of physical type (meteorological, edaphic, water resources), of use of the ground (agriculturist, forest, mining, industrial, urban, tourist, cattle dealer), economic (income, costs, benefits, infrastructures), social (population), politician (implementation, legislation), educative (Educational programs, diffusion) and environmental, at the present moment and the future. The intention is to obtain tools for aiding to get a realistic position for these challenges, which are an important part of the future problems of humanity in next decades.

Development of mathematical models to elaborate strategies, to select alternatives and the development of plans for the adaptation of communities to climate change in different geographical areas including costs to implement it

Climate change is on the policy agenda at the global level, with the aim of understanding and reducing its causes and to mitigate its consequences. In most of the countries and international organisms UNO, OECD, EC, etc … the efforts and debates have been directed to know the possible causes, to predict the future evolution of some variable conditioners, and trying to make studies to fight against the effects or to delay the negative evolution of such. Nevertheless, the elaboration of a global model was not boarded that can help to choose the best alternative between the feasible ones, to elaborate the strategies and to evaluate the costs. As in all natural, technological and social changes, the best-prepared countries will have the best bear and the more rapid recover. In all the geographic areas the alternative will not be the same one, but the model should help us to make the appropriated decision. It is essential to know those areas that are more sensitive to the negative effects of climate change, the parameters to take into account for its evaluation, and comprehensive plans to deal with it. The objective of this paper is to elaborate a mathematical model support of decisions, that will allow to develop and to evaluate alternatives of adaptation to the climatic change of different communities in Europe and Latin-America, mainly, in vulnerable areas to the climatic change, considering in them all the intervening factors. The models will take into consideration criteria of physical type (meteorological, edaphic, water resources), of use of the ground (agriculturist, forest, mining, industrial, urban, tourist, cattle dealer), economic (income, costs, benefits, infrastructures), social (population), politician (implementation, legislation), educative (Educational programs, diffusion), sanitary and environmental, at the present moment and the future.

Cooperative Multi-robot Patrolling: A study of distributed approaches based on mathematical models of game theory to protect infrastructures

El principio de Teoría de Juegos permite desarrollar modelos estocásticos de patrullaje multi-robot para proteger infraestructuras criticas. La protección de infraestructuras criticas representa un gran reto para los países al rededor del mundo, principalmente después de los ataques terroristas llevados a cabo la década pasada. En este documento el termino infraestructura hace referencia a aeropuertos, plantas nucleares u otros instalaciones. El problema de patrullaje se define como la actividad de patrullar un entorno determinado para monitorear cualquier actividad o sensar algunas variables ambientales. En esta actividad, un grupo de robots debe visitar un conjunto de puntos de interés definidos en un entorno en intervalos de tiempo irregulares con propósitos de seguridad. Los modelos de partullaje multi-robot son utilizados para resolver este problema. Hasta el momento existen trabajos que resuelven este problema utilizando diversos principios matemáticos. Los modelos de patrullaje multi-robot desarrollados en esos trabajos representan un gran avance en este campo de investigación. Sin embargo, los modelos con los mejores resultados no son viables para aplicaciones de seguridad debido a su naturaleza centralizada y determinista. Esta tesis presenta cinco modelos de patrullaje multi-robot distribuidos e impredecibles basados en modelos matemáticos de aprendizaje de Teoría de Juegos. El objetivo del desarrollo de estos modelos está en resolver los inconvenientes presentes en trabajos preliminares. Con esta finalidad, el problema de patrullaje multi-robot se formuló utilizando conceptos de Teoría de Grafos, en la cual se definieron varios juegos en cada vértice de un grafo. Los modelos de patrullaje multi-robot desarrollados en este trabajo de investigación se han validado y comparado con los mejores modelos disponibles en la literatura. Para llevar a cabo tanto la validación como la comparación se ha utilizado un simulador de patrullaje y un grupo de robots reales. Los resultados experimentales muestran que los modelos de patrullaje desarrollados en este trabajo de investigación trabajan mejor que modelos de trabajos previos en el 80% de 150 casos de estudio. Además de esto, estos modelos cuentan con varias características importantes tales como distribución, robustez, escalabilidad y dinamismo. Los avances logrados con este trabajo de investigación dan evidencia del potencial de Teoría de Juegos para desarrollar modelos de patrullaje útiles para proteger infraestructuras. ABSTRACT Game theory principle allows to developing stochastic multi-robot patrolling models to protect critical infrastructures. Critical infrastructures protection is a great concern for countries around the world, mainly due to terrorist attacks in the last decade. In this document, the term infrastructures includes airports, nuclear power plants, and many other facilities. The patrolling problem is defined as the activity of traversing a given environment to monitoring any activity or sensing some environmental variables If this activity were performed by a fleet of robots, they would have to visit some places of interest of an environment at irregular intervals of time for security purposes. This problem is solved using multi-robot patrolling models. To date, literature works have been solved this problem applying various mathematical principles.The multi-robot patrolling models developed in those works represent great advances in this field. However, the models that obtain the best results are unfeasible for security applications due to their centralized and predictable nature. This thesis presents five distributed and unpredictable multi-robot patrolling models based on mathematical learning models derived from Game Theory. These multi-robot patrolling models aim at overcoming the disadvantages of previous work. To this end, the multi-robot patrolling problem was formulated using concepts of Graph Theory to represent the environment. Several normal-form games were defined at each vertex of a graph in this formulation. The multi-robot patrolling models developed in this research work have been validated and compared with best ranked multi-robot patrolling models in the literature. Both validation and comparison were preformed by using both a patrolling simulator and real robots. Experimental results show that the multirobot patrolling models developed in this research work improve previous ones in as many as 80% of 150 cases of study. Moreover, these multi-robot patrolling models rely on several features to highlight in security applications such as distribution, robustness, scalability, and dynamism. The achievements obtained in this research work validate the potential of Game Theory to develop patrolling models to protect infrastructures.

Morteros acumuladores con parafinas microencapsuladas para el aprovechamiento de la energía solar en suelos radiantes

Esta Tesis plantea la pregunta de si el uso de morteros con parafinas microencapsuladas combinado con colectores solares térmicos puede reducir el consumo de energías convencionales, en un sistema tradicional de suelo radiante. Se pretende contribuir al conocimiento acerca del efecto que produce en el edificio, el calor latente acumulado en suelos radiantes, utilizando morteros de cemento Portland con material de cambio de fase (PCM), en conjunto con la energía solar. Para cumplir con este propósito, la investigación se desarrolla considerando diversos aspectos. En primer lugar, se revisa y analiza la documentación disponible en la actualidad, de almacenamiento de energía mediante calor latente en la construcción, y en particular la aplicación de microcápsulas de PCM en morteros y suelos radiantes. También se revisa la documentación relacionada con la aplicación de la energía solar térmica y en suelo radiante. Se analiza la normativa vigente respecto al material, a los colectores solares y al suelo radiante. Se verifica que no hay normativa relacionada con mortero-PCM, debido a esto se aplica en la investigación una adaptación de la existente. La fase experimental desarrollada esta principalmente dirigida a la cuantificación, caracterización y evaluación de las propiedades físicas, mecánicas y térmicas del mortero de cemento Portland con parafinas microencapsuladas. Los resultados obtenidos y su análisis, permiten conocer el comportamiento de este tipo de morteros, con las diferentes variables aplicadas en la investigación. Además, permite disponer de la información necesaria, para crear una metodología para el diseño de morteros con parafina microencapsulada, tanto del punto de vista de su resistencia a la compresión y contenido de PCM, como de su comportamiento térmico como acumulador de calor. Esto se logra procesando la información obtenida y generando modelos matemáticos, para dosificar mezclas, y predecir la acumulación de calor en función de su composición. Se determinan los tipos y cantidades de PCM, y el cemento más adecuado. Se obtienen importantes conclusiones respecto a los aspectos constructivos a considerar en la aplicación de morteros con PCM, en suelo radiante. Se analiza y evalúa la demanda térmica que se puede cubrir con el suelo radiante, utilizando morteros con parafina microencapsulada, a través de la acumulación de energía solar producida por colectores solares, para condiciones climáticas, técnicas y tipologías constructivas específicas. Se determina que cuando los paneles cubren más de 60 % de la demanda por calefacción, se puede almacenar en los morteros con PCM, el excedente generado durante el día. Se puede cubrir la demanda de acumulación de energía con los morteros con PCM, en la mayoría de los casos analizados. Con esto, se determina que el uso de morteros con PCM, aporta a la eficiencia energética de los edificios, disminuyendo el consumo de energías convencionales, reemplazándola por energía solar térmica. En esta investigación, el énfasis está en las propiedades del material mortero de cemento-PCM y en poder generar metodologías que faciliten su uso. Se aborda el uso de la energía solar, para verificar que es posible su acumulación en morteros con PCM aplicados en suelo radiante, posibilitando el reemplazo de energías convencionales. Quedan algunos aspectos de la aplicación de energía solar a suelo radiante con morteros con PCM, que no han sido tratados con la profundidad que requieren, y que resultan interesantes de evaluar en este tipo de aplicaciones constructivas, como entre otros, los relacionados con la cuantificación de los ahorros de energía en las diferentes estaciones del año, de la estabilización de temperaturas internas, su análisis de costo y la optimización de este tipo de sistemas para utilización en verano, los que dan pie para otras Tesis o proyectos de investigación. ABSTRACT This Thesis proposes the question of whether the use of mortars with microencapsulated paraffin combined with solar thermal collectors can reduce conventional energy consumption in a traditional heating floor system. It aims to contribute to knowledge about the effect that it has on the building, the latent heat accumulated in heating floor, using Portland cement mortars with phase change material (PCM), in conjunction with solar energy. To fulfill this purpose, the research develops it considering various aspects. First, it reviews and analyzes the documentation available today, about energy storage by latent heat in the building, and in particular the application of PCM microcapsules in mortars and heating floors. It also reviews the documentation related to the application of solar thermal energy and heating floor. Additionally, it analyzes the current regulations regarding to material, solar collectors and heating floors. It verifies that there aren’t regulations related to PCM mortar, due to this, it applies an adaptation in the investigation. The experimental phase is aimed to the quantification, mainly, characterization and evaluation of physical, mechanical and thermal properties of Portland cement mortar with microencapsulated paraffin. The results and analysis, which allow us to know the behavior of this type of mortars with different variables applied in research. It also allows having the information necessary to create a methodology for designing mortars with microencapsulated paraffin, both from the standpoint of its resistance to compression and PCM content, and its thermal performance as a heat accumulator. This accomplishes by processing the information obtained, and generating mathematical models for dosing mixtures, and predicting heat accumulation depending on their composition. The research determines the kinds and amounts of PCM, and the most suitable cement. Relevant conclusions obtain it regarding constructive aspects to consider in the implementation of PCM mortars in heating floor. Also, it analyzes and evaluates the thermal demand that it can be covered in heating floor using microencapsulated paraffin mortars, through the accumulation of solar energy produced by solar collectors to weather conditions, technical and specific building typologies. It determines that if the panels cover more than 60% of the demand for heating, the surplus generated during the day can be stored in PCM mortars. It meets the demand of energy storage with PCM mortars, in most of the cases analyzed. With this, it determines that the use of PCM mortars contributes to building energy efficiency, reducing consumption of conventional energy, replacing it with solar thermal energy. In this research approaches the use of solar energy to determine that it’s possible to verify its accumulation in PCM mortars applied in heating floor, enabling the replacement of conventional energy. The emphasis is on material properties of PCM mortar and, in order to generate methodologies to facilitate their use. There are some aspects of solar energy application in PCM mortars in heating floor, which have not been discussed with the depth required, and that they are relevant to evaluate in this kind of construction applications, including among others: the applications related to the energy savings quantification in different seasons of the year, the stabilizing internal temperatures, its cost analysis and optimization of these systems for use in summer, which can give ideas for other thesis or research projects.

Medida de la conductividad térmica con el método de la aguja térmica, basado en la fuente lineal de calor transitorio, para su aplicación en los cerramientos de adobes y bloques de tierra comprimida

Existe un creciente interés internacional por el ahorro energético y la sostenibilidad en la edificación con importantes repercusiones en la Arquitectura. La inercia térmica es un parámetro fundamental para poder valorar energéticamente un edificio en condiciones reales. Para ello es necesario cambiar el enfoque tradicional de transmisión de calor en régimen estacionario por otro en régimen dinámico en el que se analizan las ondas térmicas y el flujo de calor oscilante que atraviesan los cerramientos. Los parámetros que definen la inercia térmica son: el espesor, la difusividad y el ciclo térmico. A su vez la difusividad está determinada por la conductividad térmica, la densidad y el calor específico del material. De estos parámetros la conductividad es el más complejo, variable y difícil de medir, especialmente en los cerramientos de tierra debido a su heterogeneidad y complejidad higrotérmica. En general, los métodos de medida de la conductividad o transmitancias en los paramentos presentan inconvenientes a la hora de medir un edificio construido con tierra: dificultades de implementación, el elevado coste o la fiabilidad de los resultados, principalmente. El Método de la Aguja Térmica (MAT) se basa en el principio de la evolución en el tiempo del calor emitido por una fuente lineal al insertarse en el seno de un material. Se ha escogido este método porque resulta práctico, de bajo coste y de fácil aplicación a gran escala pero tiene serios problemas de fiabilidad y exactitud. En esta tesis se desarrolla un método de medida de la conductividad térmica para Piezas de Albañilería de Tierra Cruda en laboratorio basado en el MAT, se mejora su fiabilidad, se analiza su incertidumbre, se compara con otros métodos de referencia y se aplica en adobes, Bloques de Tierra Comprimida y probetas de tierra estabilizada con distintas proporciones de paja. Este método servirá de base a una posterior aplicación in situ. Finalmente se proponen modelos matemáticos para mejorar la exactitud del dispositivo utilizado y para la estimación de la conductividad de cerramientos de tierra en función de su densidad. Con los resultados obtenidos se analizan las posibilidades de amortiguación y retardo de las ondas térmicas y capacidad de almacenaje de energía de los cerramientos en función de su densidad y humedad. There is growing international interest in energy saving and sustainability in buildings with significant impact on Architecture. Thermal inertia is a key parameter to assess energy in buildings in real conditions. This requires changing the traditional approach to heat transfer in steady state by another in dynamic regime which analyzes the thermal waves and oscillating heat flux passing through the external walls. The parameters defining the thermal inertia are: the thickness, the diffusivity and the thermal cycle. In turn, the diffusivity is determined by the thermal conductivity, density and specific heat of the material. Of these parameters, thermal conductivity is the most complex, variable and difficult to measure, especially in earth walls due to their heterogeneity and hygrothermal complexity. In general, the methods of measurement of conductivity and transmittance in walls have drawbacks when measuring a building with earth: implementation difficulties, high cost, or reliability of the results, mainly. The Thermal Needle Procedure (TNP) is based on the principle of evolution in time of heat from a line source when inserted within a material. This method was chosen because it is a practical, low cost and easy to implement on a large scale but has serious problems of reliability and accuracy. This thesis develops a laboratory method for measuring the thermal conductivity of Masonry Units Unfire Earth-based based on TNP, its uncertainty is analyzed, compared to other reference methods and applies in adobes, Compressed Earth Blocks and stabilized soil specimens with different proportions of straw. This method will form the basis of a subsequent application in situ. Finally, mathematical models are proposed to improve the accuracy of the device used, and to estimate the conductivity of earth enclosures depending on its density. With the results obtained earth enclosures are analyzed to estimate their possibilities of delay and buffer of termal waves and energy storage capacity according to their density and moisture.

Mejora de los modelos térmicos de las presas bóveda en explotación : aplicación al análisis del efecto del cambio climático

Las cargas de origen térmico causadas por las acciones medioambientales generan esfuerzos apreciables en estructuras hiperestáticas masivas, como es el caso de las presas bóvedas. Ciertas investigaciones apuntan que la variación de la temperatura ambiental es la segunda causa de reparaciones en las presas del hormigón en servicio. Del mismo modo, es una causa de fisuración en un porcentaje apreciable de casos. Las presas son infraestructuras singulares por sus dimensiones, su vida útil, su impacto sobre el territorio y por el riesgo que implica su presencia. La evaluación de ese riesgo requiere, entre otras herramientas, de modelos matemáticos de predicción del comportamiento. Los modelos han de reproducir la realidad del modo más fidedigno posible. Además, en un escenario de posible cambio climático en el que se prevé un aumento de las temperaturas medias, la sociedad ha de conocer cuál será el comportamiento estructural de las infraestructuras sensibles en los futuros escenarios climáticos. No obstante, existen escasos estudios enfocados a determinar el campo de temperaturas de las presas de hormigón. Así, en esta investigación se han mejorado los modelos de cálculo térmico existentes con la incorporación de nuevos fenómenos físicos de transferencia de calor entre la estructura y el medio ambiente que la rodea. También se han propuesto nuevas metodologías más eficientes para cuantificar otros mecanismos de transferencia de calor. La nueva metodología se ha aplicado a un caso de estudio donde se disponía de un amplio registro de temperaturas de su hormigón. Se ha comprobado la calidad de las predicciones realizadas por los diversos modelos térmicos en el caso piloto. También se han comparado los resultados de los diversos modelos entre sí. Finalmente, se ha determinado las consecuencias de las predicciones de las temperaturas por algunos de los modelos térmicos sobre la respuesta estructural del caso de estudio. Los modelos térmicos se han empleado para caracterizar térmicamente las presas bóveda. Se ha estudiado el efecto de ciertas variables atmosféricas y determinados aspectos geométricos de las presas sobre su respuesta térmica. También se ha propuesto una metodología para evaluar la respuesta térmica y estructural de las infraestructuras frente a los posibles cambios meteorológicos inducidos por el cambio climático. La metodología se ha aplicado a un caso de estudio, una presa bóveda, y se ha obtenido su futura respuesta térmica y estructural frente a diversos escenarios climáticos. Frente a este posible cambio de las variables meteorológicas, se han detallado diversas medidas de adaptación y se ha propuesto una modificación de la normativa española de proyecto de presas en el punto acerca del cálculo de la distribución de temperaturas de diseño. Finalmente, se han extraído una serie de conclusiones y se han sugerido posibles futuras líneas de investigación para ampliar el conocimiento del fenómeno de la distribución de temperaturas en el interior de las presas y las consecuencias sobre su respuesta estructural. También se han propuesto futuras investigaciones para desarrollar nuevos procedimiento para definir las cargas térmicas de diseño, así como posibles medidas de adaptación frente al cambio climático. Thermal loads produced by external temperature variations may cause stresses in massive hyperstatic structures, such as arch dams. External temperature changes are pointed out as the second most major repairs in dams during operation. Moreover, cracking is caused by thermal loads in a quite number of cases. Dams are unique infrastructures given their dimensions, lifetime, spatial impacts and the risks involve by their presence. The risks are assessed by means of mathematical models which compute the behavior of the structure. The behavior has to be reproduced as reliable as possible. Moreover, since mean temperature on Earth is expected to increase, society has to know the structural behavior of sensitive structures to climate change. However, few studies have addressed the assessment of the thermal field in concrete dams. Thermal models are improved in this research. New heat transfer phenomena have been accounted for. Moreover, new and more efficient methodologies for computing other heat transfer phenomena have been proposed. The methodology has been applied to a case study where observations from thermometers embedded in the concrete were available. Recorded data were predicted by several thermal models and the quality of the predictions was assessed. Furthermore, predictions were compared between them. Finally, the consequences on the stress calculations were analyzed. Thermal models have been used to characterize arch dams from a thermal point of view. The effect of some meteorological and geometrical variables on the thermal response of the dam has been analyzed. Moreover, a methodology for assessing the impacts of global warming on the thermal and structural behavior of infrastructures has been proposed. The methodology was applied to a case study, an arch dam, and its thermal and structural response to several future climatic scenarios was computed. In addition, several adaptation strategies has been outlined and a new formulation for computing design thermal loads in concrete dams has been proposed. Finally, some conclusions have been reported and some future research works have been outlined. Future research works will increase the knowledge of the concrete thermal field and its consequences on the structural response of the infrastructures. Moreover, research works will develope a new procedure for computing the design thermal loads and will study some adaptation strategies against the climate change.

Aplicación de la técnica de inyección del terreno por fracturación hidráulica a las cimentaciones de puentes en circunstancias de especial dificultad

La implantación de una gran obra de paso facilita en multitud de ocasiones la vida de aquellos que aprovechen las ventajas que ofrece esta estructura. Sin embargo, el camino que lleva a su construcción supone importantes y tortuosos retos cuando el terreno de cimentación presenta condiciones geotécnicas no compatibles con las grandes cargas que el viaducto necesita transmitirle para su buen funcionamiento. El trabajo que desarrolla esta Tesis Doctoral proporciona una herramienta eficaz y económica, por lo reducido de su extensión y medios, que permite allanar el camino que acomete la construcción de una estructura de tal envergadura. Mediante el análisis de la problemática del terreno y de las distintas soluciones de cimentación empleadas en la actualidad, se conduce al lector hacia una técnica de cimentación innovadora que combina la técnica del micropilotaje, para la canalización de las cargas estructurales, junto a la técnica de la inyección de fracturación hidráulica, que mejorará el terreno de implantación de los micropilotes, conformando así un medio capaz de recibir y transmitir grandes cargas en cualquier tipo de terreno. La técnica ya empleada del micropilotaje, por su trabajo esencialmente axil, requiere, aunque sin problema, la constitución de sistemas de fuerzas que equilibren el sistema de cargas provenientes del viaducto. Pero su capacidad resistente viene condicionada por el terreno circundante. Cuando la roca rodea el micropilote, su empleo se realiza sin problema y sin necesidad de mejorar el terreno. Pero sin terreno consistente, el empleo de inyecciones de fracturación hidráulica a través de los propios micropilotes, no sólo mejorará la capacidad resistente de los micropilotes, aumentando la inercia necesaria cuando las cargas son de origen sísmico o estructural ferroviario, sino que resolverá y eliminará los problemas de estabilidad que presentan las laderas que frecuentemente deben recibir las cargas de la obra de paso. Tras recoger el análisis ya realizado en el Trabajo de Investigación, donde se justificaba la alta capacidad resistente de un micropilote con terreno circundante mejorado por la inyección, en la actual Tesis se emplean modelos matemáticos sobre un caso real de viaducto sometido a un gran sismo e implantado en una enorme quebrada (500 m) de Colombia, sujeta a lluvias torrenciales y en la zona de mayor sismicidad del país. Con ello se comprueba la estabilización que se alcanza en el terreno de cimentación con el empleo de esta técnica de transmisión de carga y mejora del terreno. De esta forma se completa un ciclo que justifica las bondades de esta combinación de técnicas de cimentación, pero se abren las puertas a nuevos entornos de aplicación, como edificios antiguos de cualquier tipo que requieran recalces, y no sólo en la implantación de grandes obras de paso. ABSTRACT The establishment of a large bridge represents, in many cases, a better life for those who can take profit of the advantages provided by that structure. Nevertheless, the process of building this structure has to overcome important and difficult circumstances whenever the geotechnical conditions of the bridge site are not adequate to carry the large loads transmitted by the bridge structure. This study develops a method both effective and economical, due to the extension and means necessary for its application, which allows to solve properly the foundation of a structure of that importance. Considering the geotechnical problems inherent to the bridge site, along with the different foundation solutions that are presently used and their limitations, the study leads the reader to an innovative technique which combines the micropile system, for transmission of the structural loads of the bridge, with the technique of hydraulic fracture grouting for improvement of the ground around the micropiles, allowing to both stabilizing and transmitting large loads in any kind of ground. It is well known that the micropiles work axially, and this condition requires an adequate distribution of those units, in order to properly absorb the load system introduced by the viaduct. The resistance of the bridge foundation is, in any case, provided by the ground. When rock is encountered, the micropiles have been successfully used without improving the ground. However, as it is shown in this study, by using the micropiles as sleeve-pipes for hydraulic fracture grouting, not only the micropile resistance can be improved in any ground, but it is possible to develop grouted “solids” in the ground, whose inertia allows to absorb actions of structural and seismic origin. Additionally, as it is shown and analyzed in the Thesis, the ground improvement can give an adequate safety factor to the slopes frequently encountered in bridge sites. In order to properly justify those advantages of combining micropiles with ground improvement through fracture grouting around the micropiles, mathematical models have been developed and applied to a real case of a cable-stayed bridge installed on a very large ravine (500 m) in Colombia, located in the highest seismic zone of the country, and subject to torrential rains. The results of this numerical analysis show the high safety condition provided by the ground improvement to the viaduct site. In conclusion, the Thesis shows the important improvement that can be provided by the combination of micropiles and soil improvement, through fracture grouting, to the problem of founding bridges. However, it can be understood that this technique could be applied successfully to underpinning buildings, specially old buildings of any type, apart from its use in bridge foundations.

Contributions to the Resilience Management in the Internet of Things

El auge del "Internet de las Cosas" (IoT, "Internet of Things") y sus tecnologías asociadas han permitido su aplicación en diversos dominios de la aplicación, entre los que se encuentran la monitorización de ecosistemas forestales, la gestión de catástrofes y emergencias, la domótica, la automatización industrial, los servicios para ciudades inteligentes, la eficiencia energética de edificios, la detección de intrusos, la gestión de desastres y emergencias o la monitorización de señales corporales, entre muchas otras. La desventaja de una red IoT es que una vez desplegada, ésta queda desatendida, es decir queda sujeta, entre otras cosas, a condiciones climáticas cambiantes y expuestas a catástrofes naturales, fallos de software o hardware, o ataques maliciosos de terceros, por lo que se puede considerar que dichas redes son propensas a fallos. El principal requisito de los nodos constituyentes de una red IoT es que estos deben ser capaces de seguir funcionando a pesar de sufrir errores en el propio sistema. La capacidad de la red para recuperarse ante fallos internos y externos inesperados es lo que se conoce actualmente como "Resiliencia" de la red. Por tanto, a la hora de diseñar y desplegar aplicaciones o servicios para IoT, se espera que la red sea tolerante a fallos, que sea auto-configurable, auto-adaptable, auto-optimizable con respecto a nuevas condiciones que puedan aparecer durante su ejecución. Esto lleva al análisis de un problema fundamental en el estudio de las redes IoT, el problema de la "Conectividad". Se dice que una red está conectada si todo par de nodos en la red son capaces de encontrar al menos un camino de comunicación entre ambos. Sin embargo, la red puede desconectarse debido a varias razones, como que se agote la batería, que un nodo sea destruido, etc. Por tanto, se hace necesario gestionar la resiliencia de la red con el objeto de mantener la conectividad entre sus nodos, de tal manera que cada nodo IoT sea capaz de proveer servicios continuos, a otros nodos, a otras redes o, a otros servicios y aplicaciones. En este contexto, el objetivo principal de esta tesis doctoral se centra en el estudio del problema de conectividad IoT, más concretamente en el desarrollo de modelos para el análisis y gestión de la Resiliencia, llevado a la práctica a través de las redes WSN, con el fin de mejorar la capacidad la tolerancia a fallos de los nodos que componen la red. Este reto se aborda teniendo en cuenta dos enfoques distintos, por una parte, a diferencia de otro tipo de redes de dispositivos convencionales, los nodos en una red IoT son propensos a perder la conexión, debido a que se despliegan en entornos aislados, o en entornos con condiciones extremas; por otra parte, los nodos suelen ser recursos con bajas capacidades en términos de procesamiento, almacenamiento y batería, entre otros, por lo que requiere que el diseño de la gestión de su resiliencia sea ligero, distribuido y energéticamente eficiente. En este sentido, esta tesis desarrolla técnicas auto-adaptativas que permiten a una red IoT, desde la perspectiva del control de su topología, ser resiliente ante fallos en sus nodos. Para ello, se utilizan técnicas basadas en lógica difusa y técnicas de control proporcional, integral y derivativa (PID - "proportional-integral-derivative"), con el objeto de mejorar la conectividad de la red, teniendo en cuenta que el consumo de energía debe preservarse tanto como sea posible. De igual manera, se ha tenido en cuenta que el algoritmo de control debe ser distribuido debido a que, en general, los enfoques centralizados no suelen ser factibles a despliegues a gran escala. El presente trabajo de tesis implica varios retos que conciernen a la conectividad de red, entre los que se incluyen: la creación y el análisis de modelos matemáticos que describan la red, una propuesta de sistema de control auto-adaptativo en respuesta a fallos en los nodos, la optimización de los parámetros del sistema de control, la validación mediante una implementación siguiendo un enfoque de ingeniería del software y finalmente la evaluación en una aplicación real. Atendiendo a los retos anteriormente mencionados, el presente trabajo justifica, mediante una análisis matemático, la relación existente entre el "grado de un nodo" (definido como el número de nodos en la vecindad del nodo en cuestión) y la conectividad de la red, y prueba la eficacia de varios tipos de controladores que permiten ajustar la potencia de trasmisión de los nodos de red en respuesta a eventuales fallos, teniendo en cuenta el consumo de energía como parte de los objetivos de control. Así mismo, este trabajo realiza una evaluación y comparación con otros algoritmos representativos; en donde se demuestra que el enfoque desarrollado es más tolerante a fallos aleatorios en los nodos de la red, así como en su eficiencia energética. Adicionalmente, el uso de algoritmos bioinspirados ha permitido la optimización de los parámetros de control de redes dinámicas de gran tamaño. Con respecto a la implementación en un sistema real, se han integrado las propuestas de esta tesis en un modelo de programación OSGi ("Open Services Gateway Initiative") con el objeto de crear un middleware auto-adaptativo que mejore la gestión de la resiliencia, especialmente la reconfiguración en tiempo de ejecución de componentes software cuando se ha producido un fallo. Como conclusión, los resultados de esta tesis doctoral contribuyen a la investigación teórica y, a la aplicación práctica del control resiliente de la topología en redes distribuidas de gran tamaño. Los diseños y algoritmos presentados pueden ser vistos como una prueba novedosa de algunas técnicas para la próxima era de IoT. A continuación, se enuncian de forma resumida las principales contribuciones de esta tesis: (1) Se han analizado matemáticamente propiedades relacionadas con la conectividad de la red. Se estudia, por ejemplo, cómo varía la probabilidad de conexión de la red al modificar el alcance de comunicación de los nodos, así como cuál es el mínimo número de nodos que hay que añadir al sistema desconectado para su re-conexión. (2) Se han propuesto sistemas de control basados en lógica difusa para alcanzar el grado de los nodos deseado, manteniendo la conectividad completa de la red. Se han evaluado diferentes tipos de controladores basados en lógica difusa mediante simulaciones, y los resultados se han comparado con otros algoritmos representativos. (3) Se ha investigado más a fondo, dando un enfoque más simple y aplicable, el sistema de control de doble bucle, y sus parámetros de control se han optimizado empleando algoritmos heurísticos como el método de la entropía cruzada (CE, "Cross Entropy"), la optimización por enjambre de partículas (PSO, "Particle Swarm Optimization"), y la evolución diferencial (DE, "Differential Evolution"). (4) Se han evaluado mediante simulación, la mayoría de los diseños aquí presentados; además, parte de los trabajos se han implementado y validado en una aplicación real combinando técnicas de software auto-adaptativo, como por ejemplo las de una arquitectura orientada a servicios (SOA, "Service-Oriented Architecture"). ABSTRACT The advent of the Internet of Things (IoT) enables a tremendous number of applications, such as forest monitoring, disaster management, home automation, factory automation, smart city, etc. However, various kinds of unexpected disturbances may cause node failure in the IoT, for example battery depletion, software/hardware malfunction issues and malicious attacks. So, it can be considered that the IoT is prone to failure. The ability of the network to recover from unexpected internal and external failures is known as "resilience" of the network. Resilience usually serves as an important non-functional requirement when designing IoT, which can further be broken down into "self-*" properties, such as self-adaptive, self-healing, self-configuring, self-optimization, etc. One of the consequences that node failure brings to the IoT is that some nodes may be disconnected from others, such that they are not capable of providing continuous services for other nodes, networks, and applications. In this sense, the main objective of this dissertation focuses on the IoT connectivity problem. A network is regarded as connected if any pair of different nodes can communicate with each other either directly or via a limited number of intermediate nodes. More specifically, this thesis focuses on the development of models for analysis and management of resilience, implemented through the Wireless Sensor Networks (WSNs), which is a challenging task. On the one hand, unlike other conventional network devices, nodes in the IoT are more likely to be disconnected from each other due to their deployment in a hostile or isolated environment. On the other hand, nodes are resource-constrained in terms of limited processing capability, storage and battery capacity, which requires that the design of the resilience management for IoT has to be lightweight, distributed and energy-efficient. In this context, the thesis presents self-adaptive techniques for IoT, with the aim of making the IoT resilient against node failures from the network topology control point of view. The fuzzy-logic and proportional-integral-derivative (PID) control techniques are leveraged to improve the network connectivity of the IoT in response to node failures, meanwhile taking into consideration that energy consumption must be preserved as much as possible. The control algorithm itself is designed to be distributed, because the centralized approaches are usually not feasible in large scale IoT deployments. The thesis involves various aspects concerning network connectivity, including: creation and analysis of mathematical models describing the network, proposing self-adaptive control systems in response to node failures, control system parameter optimization, implementation using the software engineering approach, and evaluation in a real application. This thesis also justifies the relations between the "node degree" (the number of neighbor(s) of a node) and network connectivity through mathematic analysis, and proves the effectiveness of various types of controllers that can adjust power transmission of the IoT nodes in response to node failures. The controllers also take into consideration the energy consumption as part of the control goals. The evaluation is performed and comparison is made with other representative algorithms. The simulation results show that the proposals in this thesis can tolerate more random node failures and save more energy when compared with those representative algorithms. Additionally, the simulations demonstrate that the use of the bio-inspired algorithms allows optimizing the parameters of the controller. With respect to the implementation in a real system, the programming model called OSGi (Open Service Gateway Initiative) is integrated with the proposals in order to create a self-adaptive middleware, especially reconfiguring the software components at runtime when failures occur. The outcomes of this thesis contribute to theoretic research and practical applications of resilient topology control for large and distributed networks. The presented controller designs and optimization algorithms can be viewed as novel trials of the control and optimization techniques for the coming era of the IoT. The contributions of this thesis can be summarized as follows: (1) Mathematically, the fault-tolerant probability of a large-scale stochastic network is analyzed. It is studied how the probability of network connectivity depends on the communication range of the nodes, and what is the minimum number of neighbors to be added for network re-connection. (2) A fuzzy-logic control system is proposed, which obtains the desired node degree and in turn maintains the network connectivity when it is subject to node failures. There are different types of fuzzy-logic controllers evaluated by simulations, and the results demonstrate the improvement of fault-tolerant capability as compared to some other representative algorithms. (3) A simpler but more applicable approach, the two-loop control system is further investigated, and its control parameters are optimized by using some heuristic algorithms such as Cross Entropy (CE), Particle Swarm Optimization (PSO), and Differential Evolution (DE). (4) Most of the designs are evaluated by means of simulations, but part of the proposals are implemented and tested in a real-world application by combining the self-adaptive software technique and the control algorithms which are presented in this thesis.

Two-dimensional direct rainfall hydraulic models applied to direct calculation of hydrologic events in dams to prevent overtopping

One of the main concerns when conducting a dam test is the acute determination of the hydrograph for a specific flood event. The use of 2D direct rainfall hydraulic mathematical models on a finite elements mesh, combined with the efficiency of vector calculus that provides CUDA (Compute Unified Device Architecture) technology, enables nowadays the simulation of complex hydrological models without the need for terrain subbasin and transit splitting (as in HEC-HMS). Both the Spanish PNOA (National Plan of Aereal Orthophotography) Digital Terrain Model GRID with a 5 x 5 m accuracy and the CORINE GIS Land Cover (Coordination of INformation of the Environment) that allows assessment of the ground roughness, provide enough data to easily build these kind of models

Co-simulation Methodologies for Hybrid and Electric Vehicle Dynamics

In recent decades, full electric and hybrid electric vehicles have emerged as an alternative to conventional cars due to a range of factors, including environmental and economic aspects. These vehicles are the result of considerable efforts to seek ways of reducing the use of fossil fuel for vehicle propulsion. Sophisticated technologies such as hybrid and electric powertrains require careful study and optimization. Mathematical models play a key role at this point. Currently, many advanced mathematical analysis tools, as well as computer applications have been built for vehicle simulation purposes. Given the great interest of hybrid and electric powertrains, along with the increasing importance of reliable computer-based models, the author decided to integrate both aspects in the research purpose of this work. Furthermore, this is one of the first final degree projects held at the ETSII (Higher Technical School of Industrial Engineers) that covers the study of hybrid and electric propulsion systems. The present project is based on MBS3D 2.0, a specialized software for the dynamic simulation of multibody systems developed at the UPM Institute of Automobile Research (INSIA). Automobiles are a clear example of complex multibody systems, which are present in nearly every field of engineering. The work presented here benefits from the availability of MBS3D software. This program has proven to be a very efficient tool, with a highly developed underlying mathematical formulation. On this basis, the focus of this project is the extension of MBS3D features in order to be able to perform dynamic simulations of hybrid and electric vehicle models. This requires the joint simulation of the mechanical model of the vehicle, together with the model of the hybrid or electric powertrain. These sub-models belong to completely different physical domains. In fact the powertrain consists of energy storage systems, electrical machines and power electronics, connected to purely mechanical components (wheels, suspension, transmission, clutch…). The challenge today is to create a global vehicle model that is valid for computer simulation. Therefore, the main goal of this project is to apply co-simulation methodologies to a comprehensive model of an electric vehicle, where sub-models from different areas of engineering are coupled. The created electric vehicle (EV) model consists of a separately excited DC electric motor, a Li-ion battery pack, a DC/DC chopper converter and a multibody vehicle model. Co-simulation techniques allow car designers to simulate complex vehicle architectures and behaviors, which are usually difficult to implement in a real environment due to safety and/or economic reasons. In addition, multi-domain computational models help to detect the effects of different driving patterns and parameters and improve the models in a fast and effective way. Automotive designers can greatly benefit from a multidisciplinary approach of new hybrid and electric vehicles. In this case, the global electric vehicle model includes an electrical subsystem and a mechanical subsystem. The electrical subsystem consists of three basic components: electric motor, battery pack and power converter. A modular representation is used for building the dynamic model of the vehicle drivetrain. This means that every component of the drivetrain (submodule) is modeled separately and has its own general dynamic model, with clearly defined inputs and outputs. Then, all the particular submodules are assembled according to the drivetrain configuration and, in this way, the power flow across the components is completely determined. Dynamic models of electrical components are often based on equivalent circuits, where Kirchhoff’s voltage and current laws are applied to draw the algebraic and differential equations. Here, Randles circuit is used for dynamic modeling of the battery and the electric motor is modeled through the analysis of the equivalent circuit of a separately excited DC motor, where the power converter is included. The mechanical subsystem is defined by MBS3D equations. These equations consider the position, velocity and acceleration of all the bodies comprising the vehicle multibody system. MBS3D 2.0 is entirely written in MATLAB and the structure of the program has been thoroughly studied and understood by the author. MBS3D software is adapted according to the requirements of the applied co-simulation method. Some of the core functions are modified, such as integrator and graphics, and several auxiliary functions are added in order to compute the mathematical model of the electrical components. By coupling and co-simulating both subsystems, it is possible to evaluate the dynamic interaction among all the components of the drivetrain. ‘Tight-coupling’ method is used to cosimulate the sub-models. This approach integrates all subsystems simultaneously and the results of the integration are exchanged by function-call. This means that the integration is done jointly for the mechanical and the electrical subsystem, under a single integrator and then, the speed of integration is determined by the slower subsystem. Simulations are then used to show the performance of the developed EV model. However, this project focuses more on the validation of the computational and mathematical tool for electric and hybrid vehicle simulation. For this purpose, a detailed study and comparison of different integrators within the MATLAB environment is done. Consequently, the main efforts are directed towards the implementation of co-simulation techniques in MBS3D software. In this regard, it is not intended to create an extremely precise EV model in terms of real vehicle performance, although an acceptable level of accuracy is achieved. The gap between the EV model and the real system is filled, in a way, by introducing the gas and brake pedals input, which reflects the actual driver behavior. This input is included directly in the differential equations of the model, and determines the amount of current provided to the electric motor. For a separately excited DC motor, the rotor current is proportional to the traction torque delivered to the car wheels. Therefore, as it occurs in the case of real vehicle models, the propulsion torque in the mathematical model is controlled through acceleration and brake pedal commands. The designed transmission system also includes a reduction gear that adapts the torque coming for the motor drive and transfers it. The main contribution of this project is, therefore, the implementation of a new calculation path for the wheel torques, based on performance characteristics and outputs of the electric powertrain model. Originally, the wheel traction and braking torques were input to MBS3D through a vector directly computed by the user in a MATLAB script. Now, they are calculated as a function of the motor current which, in turn, depends on the current provided by the battery pack across the DC/DC chopper converter. The motor and battery currents and voltages are the solutions of the electrical ODE (Ordinary Differential Equation) system coupled to the multibody system. Simultaneously, the outputs of MBS3D model are the position, velocity and acceleration of the vehicle at all times. The motor shaft speed is computed from the output vehicle speed considering the wheel radius, the gear reduction ratio and the transmission efficiency. This motor shaft speed, somehow available from MBS3D model, is then introduced in the differential equations corresponding to the electrical subsystem. In this way, MBS3D and the electrical powertrain model are interconnected and both subsystems exchange values resulting as expected with tight-coupling approach.When programming mathematical models of complex systems, code optimization is a key step in the process. A way to improve the overall performance of the integration, making use of C/C++ as an alternative programming language, is described and implemented. Although this entails a higher computational burden, it leads to important advantages regarding cosimulation speed and stability. In order to do this, it is necessary to integrate MATLAB with another integrated development environment (IDE), where C/C++ code can be generated and executed. In this project, C/C++ files are programmed in Microsoft Visual Studio and the interface between both IDEs is created by building C/C++ MEX file functions. These programs contain functions or subroutines that can be dynamically linked and executed from MATLAB. This process achieves reductions in simulation time up to two orders of magnitude. The tests performed with different integrators, also reveal the stiff character of the differential equations corresponding to the electrical subsystem, and allow the improvement of the cosimulation process. When varying the parameters of the integration and/or the initial conditions of the problem, the solutions of the system of equations show better dynamic response and stability, depending on the integrator used. Several integrators, with variable and non-variable step-size, and for stiff and non-stiff problems are applied to the coupled ODE system. Then, the results are analyzed, compared and discussed. From all the above, the project can be divided into four main parts: 1. Creation of the equation-based electric vehicle model; 2. Programming, simulation and adjustment of the electric vehicle model; 3. Application of co-simulation methodologies to MBS3D and the electric powertrain subsystem; and 4. Code optimization and study of different integrators. Additionally, in order to deeply understand the context of the project, the first chapters include an introduction to basic vehicle dynamics, current classification of hybrid and electric vehicles and an explanation of the involved technologies such as brake energy regeneration, electric and non-electric propulsion systems for EVs and HEVs (hybrid electric vehicles) and their control strategies. Later, the problem of dynamic modeling of hybrid and electric vehicles is discussed. The integrated development environment and the simulation tool are also briefly described. The core chapters include an explanation of the major co-simulation methodologies and how they have been programmed and applied to the electric powertrain model together with the multibody system dynamic model. Finally, the last chapters summarize the main results and conclusions of the project and propose further research topics. In conclusion, co-simulation methodologies are applicable within the integrated development environments MATLAB and Visual Studio, and the simulation tool MBS3D 2.0, where equation-based models of multidisciplinary subsystems, consisting of mechanical and electrical components, are coupled and integrated in a very efficient way.

Application of the dynamic models to the detection of imperfections in plate Structures

This paper is part of a set of publications related with the development of mathematical models aimed to simulate the dynamic input and output of experimental nondestructive tests in order to detect structural imperfections. The structures to be considered are composed by steel plates of thin thickness. The imperfections in these cases are cracks and they can penetrate either a significant part of the plate thickness or be micro cracks or superficial imperfections. The first class of cracks is related with structural safety and the second one is more connected to the structural protection to the environment, particularly if protective paintings can be deteriorated. Two mathematical groups of models have been developed. The first group tries to locate the position and extension of the imperfection of the first class of imperfections, i.e. cracks and it is the object of the present paper. Bending Kirchoff thin plate models belong to this first group and they are used to this respect. The another group of models is dealt with membrane structures under the superficial Rayleigh waves excitation. With this group of models the micro cracks detection is intended. In the application of the first group of models to the detection of cracks, it has been observed that the differences between the natural frequencies of the non cracked and the cracked structures are very small. However, geometry and crack position can be identified quite accurately if this comparison is carried out between first derivatives (mode rotations) of the natural modes are used instead. Finally, in relation with the analysis of the superficial crack existence the use of Rayleigh waves is very promising. The geometry and the penetration of the micro crack can be detected very accurately. The mathematical and numerical treatment of the generation of these Rayleigh waves present and a numerical application has been shown.