The Role of Knowledge Modeling Techniques in Software Development: A General Approach Based on a Knowledge Management Tool

The aim of the paper is to discuss the use of knowledge models to formulate general applications. First, the paper presents the recent evolution of the software field where increasing attention is paid to conceptual modeling. Then, the current state of knowledge modeling techniques is described where increased reliability is available through the modern knowledge acquisition techniques and supporting tools. The KSM (Knowledge Structure Manager) tool is described next. First, the concept of knowledge area is introduced as a building block where methods to perform a collection of tasks are included together with the bodies of knowledge providing the basic methods to perform the basic tasks. Then, the CONCEL language to define vocabularies of domains and the LINK language for methods formulation are introduced. Finally, the object oriented implementation of a knowledge area is described and a general methodology for application design and maintenance supported by KSM is proposed. To illustrate the concepts and methods, an example of system for intelligent traffic management in a road network is described. This example is followed by a proposal of generalization for reuse of the resulting architecture. Finally, some concluding comments are proposed about the feasibility of using the knowledge modeling tools and methods for general application design.

Using Electronic Documents for Knowledge Acquisition and Model Maintenance

Knowledge acquisition and model maintenance are key problems in knowledge engineering to improve the productivity in the development of intelligent systems. Although historically a number of technical solutions have been proposed in this area, the recent experience shows that there is still an important gap between the way end-users describe their expertise and the way intelligent systems represent knowledge. In this paper we propose an original way to cope with this problem based on electronic documents. We propose the concept of intelligent document processor as a tool that allows the end-user to read/write a document explaining how an intelligent system operates in such a way that, if the user changes the content of the document, the intelligent system will react to these changes. The paper presents the structure of such a document based on knowledge categories derived from the modern knowledge modeling methodologies together with a number of requirements to be understandable by end-users and problem solvers.

KATS: A Knowledge Acquisition Tool Based on Electronic Document Processing

This paper describes a particular knowledge acquisition tool for the construction and maintenance of the knowledge model of an intelligent system for emergency management in the field of hydrology. This tool has been developed following an innovative approach directed to end-users non familiarized in computer oriented terminology. According to this approach, the tool is conceived as a document processor specialized in a particular domain (hydrology) in such a way that the whole knowledge model is viewed by the user as an electronic document. The paper first describes the characteristics of the knowledge model of the intelligent system and summarizes the problems that we found during the development and maintenance of such type of model. Then, the paper describes the KATS tool, a software application that we have designed to help in this task to be used by users who are not experts in computer programming. Finally, the paper shows a comparison between KATS and other approaches for knowledge acquisition.

Explicit expressions for solar panel equivalent circuit parameters based on analytical formulation and the Lambert W - Function

Due to the high dependence of photovoltaic energy efficiency on environmental conditions (temperature, irradiation...), it is quite important to perform some analysis focusing on the characteristics of photovoltaic devices in order to optimize energy production, even for small-scale users. The use of equivalent circuits is the preferred option to analyze solar cells/panels performance. However, the aforementioned small-scale users rarely have the equipment or expertise to perform large testing/calculation campaigns, the only information available for them being the manufacturer datasheet. The solution to this problem is the development of new and simple methods to define equivalent circuits able to reproduce the behavior of the panel for any working condition, from a very small amount of information. In the present work a direct and completely explicit method to extract solar cell parameters from the manufacturer datasheet is presented and tested. This method is based on analytical formulation which includes the use of the Lambert W-function to turn the series resistor equation explicit. The presented method is used to analyze the performance (i.e., the I - V curve) of a commercial solar panel at different levels of irradiation and temperature. The analysis performed is based only on the information included in the manufacturer's datasheet.

On the harmonic analysis of cup anemometer rotation speed: A principle to monitor performance and maintenance status of rotating meteorological sensors

The calibration results of one anemometer equipped with several rotors, varying their size, were analyzed. In each case, the 30-pulses pert turn output signal of the anemometer was studied using Fourier series decomposition and correlated with the anemometer factor (i.e., the anemometer transfer function). Also, a 3-cup analytical model was correlated to the data resulting from the wind tunnel measurements. Results indicate good correlation between the post-processed output signal and the working condition of the cup anemometer. This correlation was also reflected in the results from the proposed analytical model. With the present work the possibility of remotely checking cup anemometer status, indicating the presence of anomalies and, therefore, a decrease on the wind sensor reliability is revealed.

Identification of intermediate debonding damage in FRP-plated RC beams based on multi-objective particle swarm optimization without updated baseline model

Fiber reinforced polymer composites (FRP) have found widespread usage in the repair and strengthening of concrete structures. FRP composites exhibit high strength-to-weight ratio, corrosion resistance, and are convenient to use in repair applications. Externally bonded FRP flexural strengthening of concrete beams is the most extended application of this technique. A common cause of failure in such members is associated with intermediate crack-induced debonding (IC debonding) of the FRP substrate from the concrete in an abrupt manner. Continuous monitoring of the concrete?FRP interface is essential to pre- vent IC debonding. Objective condition assessment and performance evaluation are challenging activities since they require some type of monitoring to track the response over a period of time. In this paper, a multi-objective model updating method integrated in the context of structural health monitoring is demonstrated as promising technology for the safety and reliability of this kind of strengthening technique. The proposed method, solved by a multi-objective extension of the particle swarm optimization method, is based on strain measurements under controlled loading. The use of permanently installed fiber Bragg grating (FBG) sensors embedded into the FRP-concrete interface or bonded onto the FRP strip together with the proposed methodology results in an automated method able to operate in an unsupervised mode.

Numerical Simulation of the Aerodynamic Behavior of High Velocity Trains under Synthetic Crosswinds of Different Shear and Turbulence Characteristics

A numerical simulation of the aerodynamic behavior of high-speed trains under synthetic crosswinds at a 90�� yaw angle is presented. The train geometry is the aerodynamic train model (ATM). Flow description based on numerical simulations is obtained using large eddy simulation (LES) and the commercial code ANSYSFluent V14.5. A crosswind whose averaged velocity and turbulence characteristics change with distance to the ground is imposed. Turbulent fluctuations that vary temporally and spatially are simulated with TurbSim code. The crosswind boundary condition is calculated for the distance the train runs during a simulation period. The inlet streamwise velocity boundary condition is generated using Taylor?s frozen turbulence hypothesis. The model gives a time history of the force and moments acting on the train; this includes averaged values, standard deviations and extreme values. Of particular interest are the spectra of the forces and moments, and the admittance spectra. For comparison, results obtained with LES and a uniform wind velocity fluctuating in time, and results obtained with Reynolds averaged Navier Stokes equations (RANS), and the averaged wind conditions, are also presented.

Characterisation of the operation & maintenance phase in PV rural electrification programmes

Con 1.300 millones de personas en el mundo sin acceso a la electricidad (la mayor��a en entornos rurales de pa��ses empobrecidos), la energ��a solar fotovoltaica constituye una soluci��n viable t��cnica y econ��micamente para electrificar las zonas m��s remotas del planeta donde las redes el��ctricas convencionales no llegan. Casi todos los pa��ses en el mundo han desarrollado alg��n tipo de programa de electrificaci��n fotovoltaica rural durante los ��ltimos 40 a��os, principalmente los pa��ses m��s pobres, donde a trav��s de diferentes modelos de financiaci��n, se han instalado millones de sistemas solares domiciliarios (peque��os sistemas fotovoltaicos para uso dom��stico). Durante este largo per��odo, se han ido superando muchas barreras, como la mejora de la calidad de los sistemas fotovoltaicos, la reducci��n de costes, la optimizaci��n del dise��o y del dimensionado de los sistemas, la disponibilidad financiera para implantar programas de electrificaci��n rural, etc. Gracias a esto, la electrificaci��n rural descentralizada ha experimentado recientemente un salto de escala caracterizada por la implantaci��n de grandes programas con miles de sistemas solares domiciliarios e integrando largos per��odos de mantenimiento. Muchos de estos grandes programas se est��n llevando a cabo con limitado ��xito, ya que generalmente parten de supuestos e hip��tesis poco contrastadas con la realidad, comprometiendo as�� un retorno econ��mico que permita el desarrollo de esta actividad a largo plazo. En este escenario surge un nuevo reto: el de c��mo garantizar la sostenibilidad de los grandes programas de electrificaci��n rural fotovoltaica. Se argumenta que la principal causa de esta falta de rentabilidad es el imprevisto alto coste de la fase de operaci��n y mantenimiento. Cuestiones clave tales como la estructura de costes de operaci��n y mantenimiento o la fiabilidad de los componentes del sistema fotovoltaico no est��n bien caracterizados hoy en d��a. Esta situaci��n limita la capacidad de dise��ar estructuras de mantenimiento capaces de asegurar la sostenibilidad y la rentabilidad del servicio de operaci��n y mantenimiento en estos programas. Esta tesis doctoral tiene como objetivo responder a estas cuestiones. Se ha realizado varios estudios sobre la base de un gran programa de electrificaci��n rural fotovoltaica real llevado a cabo en Marruecos con m��s de 13.000 sistemas solares domiciliarios instalados. Sobre la base de este programa se ha hecho una evaluaci��n en profundidad de la fiabilidad de los sistemas solares a partir de los datos de mantenimiento recogidos durante 5 a��os con m��s de 80.000 inputs. Los resultados han permitido establecer las funciones de fiabilidad de los equipos tal y como se comportan en condiciones reales de operaci��n, las tasas de fallos y los tiempos medios hasta el fallo para los principales componentes del sistema, siendo este el primer caso de divulgaci��n de resultados de este tipo en el campo de la electrificaci��n rural fotovoltaica. Los dos principales componentes del sistema solar domiciliario, la bater��a y el m��dulo fotovoltaico, han sido analizados en campo a trav��s de una muestra de 41 sistemas trabajando en condiciones reales pertenecientes al programa solar marroqu��. Por un lado se ha estudiado la degradaci��n de la capacidad de las bater��as y por otro la degradaci��n de potencia de los m��dulos fotovoltaicos. En el caso de las bater��as, los resultados nos han permitido caracterizar la curva de degradaci��n en capacidad llegando a obtener una propuesta de nueva definici��n del umbral de vida ��til de las bater��as en electrificaci��n rural. Tambi��n sobre la base del programa solar de Marruecos se ha llevado a cabo un estudio de caracterizaci��n de los costes reales de operaci��n y mantenimiento a partir de la base de datos de contabilidad del programa registrados durante 5 a��os. Los resultados del estudio han permitido definir cu��les son costes que m��s incidencia tienen en el coste global. Se han obtenido los costes unitarios por sistema instalado y se han calculado los montantes de las cuotas de mantenimiento de los usuarios para garantizar la rentabilidad de la operaci��n y mantenimiento. Finalmente, se propone un modelo de optimizaci��n matem��tica para dise��ar estructuras de mantenimiento basado en los resultados de los estudios anteriores. La herramienta, elaborada mediante programaci��n lineal entera mixta, se ha aplicado al programa marroqu�� con el fin de validar el modelo propuesto. ABSTRACT With 1,300 million people worldwide deprived of access to electricity (mostly in rural environments), photovoltaic solar energy has proven to be a cost���effective solution and the only hope for electrifying the most remote inhabitants of the planet, where conventional electric grids do not reach because they are unaffordable. Almost all countries in the world have had some kind of rural photovoltaic electrification programme during the past 40 years, mainly the poorer countries, where through different organizational models, millions of solar home systems (small photovoltaic systems for domestic use) have been installed. During this long period, many barriers have been overcome, such as quality enhancement, cost reduction, the optimization of designing and sizing, financial availability, etc. Thanks to this, decentralized rural electrification has recently experienced a change of scale characterized by new programmes with thousands of solar home systems and long maintenance periods. Many of these large programmes are being developed with limited success, as they have generally been based on assumptions that do not correspond to reality, compromising the economic return that allows long term activity. In this scenario a new challenge emerges, which approaches the sustainability of large programmes. It is argued that the main cause of unprofitability is the unexpected high cost of the operation and maintenance of the solar systems. In fact, the lack of a paradigm in decentralized rural services has led to many private companies to carry out decentralized electrification programmes blindly. Issues such as the operation and maintenance cost structure or the reliability of the solar home system components have still not been characterized. This situation does not allow optimized maintenance structure to be designed to assure the sustainability and profitability of the operation and maintenance service. This PhD thesis aims to respond to these needs. Several studies have been carried out based on a real and large photovoltaic rural electrification programme carried out in Morocco with more than 13,000 solar home systems. An in���depth reliability assessment has been made from a 5���year maintenance database with more than 80,000 maintenance inputs. The results have allowed us to establish the real reliability functions, the failure rate and the main time to failure of the main components of the system, reporting these findings for the first time in the field of rural electrification. Both in���field experiments on the capacity degradation of batteries and power degradation of photovoltaic modules have been carried out. During the experiments both samples of batteries and modules were operating under real conditions integrated into the solar home systems of the Moroccan programme. In the case of the batteries, the results have enabled us to obtain a proposal of definition of death of batteries in rural electrification. A cost assessment of the Moroccan experience based on a 5���year accounting database has been carried out to characterize the cost structure of the programme. The results have allowed the major costs of the photovoltaic electrification to be defined. The overall cost ratio per installed system has been calculated together with the necessary fees that users would have to pay to make the operation and maintenance affordable. Finally, a mathematical optimization model has been proposed to design maintenance structures based on the previous study results. The tool has been applied to the Moroccan programme with the aim of validating the model.

Fault management techniques for systems with SRAM-based FPGAs

Las Field-Programmable Gate Arrays (FPGAs) SRAM se construyen sobre una memoria de configuraci��n de tecnolog��a RAM Est��tica (SRAM). Presentan m��ltiples caracter��sticas que las hacen muy interesantes para dise��ar sistemas empotrados complejos. En primer lugar presentan un coste no-recurrente de ingenier��a (NRE) bajo, ya que los elementos l��gicos y de enrutado est��n pre-implementados (el dise��o de usuario define su conexionado). Tambi��n, a diferencia de otras tecnolog��as de FPGA, pueden ser reconfiguradas (incluso en campo) un n��mero ilimitado de veces. Es m��s, las FPGAs SRAM de Xilinx soportan Reconfiguraci��n Parcial Din��mica (DPR), la cual permite reconfigurar la FPGA sin interrumpir la aplicaci��n. Finalmente, presentan una alta densidad de l��gica, una alta capacidad de procesamiento y un rico juego de macro-bloques. Sin embargo, un inconveniente de esta tecnolog��a es su susceptibilidad a la radiaci��n ionizante, la cual aumenta con el grado de integraci��n (geometr��as m��s peque��as, menores tensiones y mayores frecuencias). Esta es una precupaci��n de primer nivel para aplicaciones en entornos altamente radiativos y con requisitos de alta confiabilidad. Este fen��meno conlleva una degradaci��n a largo plazo y tambi��n puede inducir fallos instant��neos, los cuales pueden ser reversibles o producir da��os irreversibles. En las FPGAs SRAM, los fallos inducidos por radiaci��n pueden aparecer en en dos capas de arquitectura diferentes, que est��n f��sicamente superpuestas en el dado de silicio. La Capa de Aplicaci��n (o A-Layer) contiene el hardware definido por el usuario, y la Capa de Configuraci��n contiene la memoria de configuraci��n y la circuiter��a de soporte. Los fallos en cualquiera de estas capas pueden hacer fracasar el sistema, lo cual puede ser ��s o menos tolerable dependiendo de los requisitos de confiabilidad del sistema. En el caso general, estos fallos deben gestionados de alguna manera. Esta tesis trata sobre la gesti��n de fallos en FPGAs SRAM a nivel de sistema, en el contexto de sistemas empotrados aut��nomos y confiables operando en un entorno radiativo. La tesis se centra principalmente en aplicaciones espaciales, pero los mismos principios pueden aplicarse a aplicaciones terrenas. Las principales diferencias entre ambas son el nivel de radiaci��n y la posibilidad de mantenimiento. Las diferentes t��cnicas para la gesti��n de fallos en A-Layer y C-Layer son clasificados, y sus implicaciones en la confiabilidad del sistema son analizados. Se proponen varias arquitecturas tanto para Gestores de Fallos de una capa como de doble-capa. Para estos ��ltimos se propone una arquitectura novedosa, flexible y vers��til. Gestiona las dos capas concurrentemente de manera coordinada, y permite equilibrar el nivel de redundancia y la confiabilidad. Con el objeto de validar t��cnicas de gesti��n de fallos din��micas, se desarrollan dos diferentes soluciones. La primera es un entorno de simulaci��n para Gestores de Fallos de C-Layer, basado en SystemC como lenguaje de modelado y como simulador basado en eventos. Este entorno y su metodolog��a asociada permite explorar el espacio de dise��o del Gestor de Fallos, desacoplando su dise��o del desarrollo de la FPGA objetivo. El entorno incluye modelos tanto para la C-Layer de la FPGA como para el Gestor de Fallos, los cuales pueden interactuar a diferentes niveles de abstracci��n (a nivel de configuration frames y a nivel f��sico JTAG o SelectMAP). El entorno es configurable, escalable y vers��til, e incluye capacidades de inyecci��n de fallos. Los resultados de simulaci��n para algunos escenarios son presentados y comentados. La segunda es una plataforma de validaci��n para Gestores de Fallos de FPGAs Xilinx Virtex. La plataforma hardware aloja tres M��dulos de FPGA Xilinx Virtex-4 FX12 y dos M��dulos de Unidad de Microcontrolador (MCUs) de 32-bits de prop��sito general. Los M��dulos MCU permiten prototipar Gestores de Fallos de C-Layer y A-Layer basados en software. Cada M��dulo FPGA implementa un enlace de A-Layer Ethernet (a trav��s de un switch Ethernet) con uno de los M��dulos MCU, y un enlace de C-Layer JTAG con el otro. Adem��s, ambos M��dulos MCU intercambian comandos y datos a trav��s de un enlace interno tipo UART. Al igual que para el entorno de simulaci��n, se incluyen capacidades de inyecci��n de fallos. Los resultados de pruebas para algunos escenarios son tambi��n presentados y comentados. En resumen, esta tesis cubre el proceso completo desde la descripci��n de los fallos FPGAs SRAM inducidos por radiaci��n, pasando por la identificaci��n y clasificaci��n de t��cnicas de gesti��n de fallos, y por la propuesta de arquitecturas de Gestores de Fallos, para finalmente validarlas por simulaci��n y pruebas. El trabajo futuro est�� relacionado sobre todo con la implementaci��n de Gestores de Fallos de Sistema endurecidos para radiaci��n. ABSTRACT SRAM-based Field-Programmable Gate Arrays (FPGAs) are built on Static RAM (SRAM) technology configuration memory. They present a number of features that make them very convenient for building complex embedded systems. First of all, they benefit from low Non-Recurrent Engineering (NRE) costs, as the logic and routing elements are pre-implemented (user design defines their connection). Also, as opposed to other FPGA technologies, they can be reconfigured (even in the field) an unlimited number of times. Moreover, Xilinx SRAM-based FPGAs feature Dynamic Partial Reconfiguration (DPR), which allows to partially reconfigure the FPGA without disrupting de application. Finally, they feature a high logic density, high processing capability and a rich set of hard macros. However, one limitation of this technology is its susceptibility to ionizing radiation, which increases with technology scaling (smaller geometries, lower voltages and higher frequencies). This is a first order concern for applications in harsh radiation environments and requiring high dependability. Ionizing radiation leads to long term degradation as well as instantaneous faults, which can in turn be reversible or produce irreversible damage. In SRAM-based FPGAs, radiation-induced faults can appear at two architectural layers, which are physically overlaid on the silicon die. The Application Layer (or A-Layer) contains the user-defined hardware, and the Configuration Layer (or C-Layer) contains the (volatile) configuration memory and its support circuitry. Faults at either layers can imply a system failure, which may be more ore less tolerated depending on the dependability requirements. In the general case, such faults must be managed in some way. This thesis is about managing SRAM-based FPGA faults at system level, in the context of autonomous and dependable embedded systems operating in a radiative environment. The focus is mainly on space applications, but the same principles can be applied to ground applications. The main differences between them are the radiation level and the possibility for maintenance. The different techniques for A-Layer and C-Layer fault management are classified and their implications in system dependability are assessed. Several architectures are proposed, both for single-layer and dual-layer Fault Managers. For the latter, a novel, flexible and versatile architecture is proposed. It manages both layers concurrently in a coordinated way, and allows balancing redundancy level and dependability. For the purpose of validating dynamic fault management techniques, two different solutions are developed. The first one is a simulation framework for C-Layer Fault Managers, based on SystemC as modeling language and event-driven simulator. This framework and its associated methodology allows exploring the Fault Manager design space, decoupling its design from the target FPGA development. The framework includes models for both the FPGA C-Layer and for the Fault Manager, which can interact at different abstraction levels (at configuration frame level and at JTAG or SelectMAP physical level). The framework is configurable, scalable and versatile, and includes fault injection capabilities. Simulation results for some scenarios are presented and discussed. The second one is a validation platform for Xilinx Virtex FPGA Fault Managers. The platform hosts three Xilinx Virtex-4 FX12 FPGA Modules and two general-purpose 32-bit Microcontroller Unit (MCU) Modules. The MCU Modules allow prototyping software-based CLayer and A-Layer Fault Managers. Each FPGA Module implements one A-Layer Ethernet link (through an Ethernet switch) with one of the MCU Modules, and one C-Layer JTAG link with the other. In addition, both MCU Modules exchange commands and data over an internal UART link. Similarly to the simulation framework, fault injection capabilities are implemented. Test results for some scenarios are also presented and discussed. In summary, this thesis covers the whole process from describing the problem of radiationinduced faults in SRAM-based FPGAs, then identifying and classifying fault management techniques, then proposing Fault Manager architectures and finally validating them by simulation and test. The proposed future work is mainly related to the implementation of radiation-hardened System Fault Managers.

Self-adaptive strategy based on fuzzy control systems for improving performance in wireless sensors networks

The solutions to cope with new challenges that societies have to face nowadays involve providing smarter daily systems. To achieve this, technology has to evolve and leverage physical systems automatic interactions, with less human intervention. Technological paradigms like Internet of Things (IoT) and Cyber-Physical Systems (CPS) are providing reference models, architectures, approaches and tools that are to support cross-domain solutions. Thus, CPS based solutions will be applied in different application domains like e-Health, Smart Grid, Smart Transportation and so on, to assure the expected response from a complex system that relies on the smooth interaction and cooperation of diverse networked physical systems. The Wireless Sensors Networks (WSN) are a well-known wireless technology that are part of large CPS. The WSN aims at monitoring a physical system, object, (e.g., the environmental condition of a cargo container), and relaying data to the targeted processing element. The WSN communication reliability, as well as a restrained energy consumption, are expected features in a WSN. This paper shows the results obtained in a real WSN deployment, based on SunSPOT nodes, which carries out a fuzzy based control strategy to improve energy consumption while keeping communication reliability and computational resources usage among boundaries.

An ICT-based closed-loop model to improve care for heart failure patients

Durante las ��ltimas d��cadas se ha producido un fen��meno global de envejecimiento en la poblaci��n. Esta tendencia se puede observar pr��cticamente en todos los pa��ses del mundo y se debe principalmente a los avances en la medicina, y a los descensos en las tasas de fertilidad y mortalidad. El envejecimiento de la poblaci��n tiene un gran impacto en la salud de los ciudadanos, y a menudo es la causa de aparici��n de enfermedades cr��nicas. Este tipo de enfermedades supone una amenaza y una carga importantes para la sociedad, especialmente en aspectos como la mortalidad o los gastos en los sistemas sanitarios. Entre las enfermedades cardiovasculares, la insuficiencia card��aca es probablemente la condici��n con mayor prevalencia y afecta a 23-26 millones de personas en todo el mundo. Normalmente, la insuficiencia card��aca presenta un mal pron��stico y una tasa de supervivencia bajas, en algunos casos peores que alg��n tipo de c��ncer. Adem��s, suele ser la causa de hospitalizaciones frecuentes y es una de las enfermedades m��s costosas para los sistemas sanitarios. La tendencia al envejecimiento de la poblaci��n y la creciente incidencia de las enfermedades cr��nicas est��n llevando a una situaci��n en la que los sistemas de salud no son capaces de hacer frente a la demanda de la sociedad. Los servicios de salud existentes tendr��n que adaptarse para ser efectivos y sostenibles en el futuro. Es necesario identificar nuevos paradigmas de cuidado de pacientes, as�� como mecanismos para la provisi��n de servicios que ayuden a transformar estos sistemas sanitarios. En este contexto, esta tesis se plantea la b��squeda de soluciones, basadas en las Tecnolog��as de la Informaci��n y la Comunicaci��n (TIC), que contribuyan a realizar la transformaci��n en los sistemas sanitarios. En concreto, la tesis se centra en abordar los problemas de una de las enfermedades con mayor impacto en estos sistemas: la insuficiencia card��aca. Las siguientes hip��tesis constituyen la base para la realizaci��n de este trabajo de investigaci��n: 1. Es posible definir un modelo basado en el paradigma de lazo cerrado y herramientas TIC que formalice el dise��o de mejores servicios para pacientes con insuficiencia card��aca. 2. El modelo de lazo cerrado definido se puede utilizar para definir un servicio real que ayude a gestionar la insuficiencia card��aca cr��nica. 3. La introducci��n, la adopci��n y el uso de un servicio basado en el modelo definido se traducir�� en mejoras en el estado de salud de los pacientes que sufren insuficiencia card��aca. a. La utilizaci��n de un sistema basado en el modelo de lazo cerrado definido mejorar�� la experiencia del usuario de los pacientes. La definici��n del modelo planteado se ha basado en el est��ndar ISO / EN 13940- Sistema de conceptos para dar soporte a la continuidad de la asistencia. Comprende un conjunto de conceptos, procesos, flujos de trabajo, y servicios como componentes principales, y representa una formalizaci��n de los servicios para los pacientes con insuficiencia card��aca. Para evaluar el modelo definido se ha definido un servicio real basado en el mismo, adem��s de la implementaci��n de un sistema de apoyo a dicho servicio. El dise��o e implementaci��n de dicho sistema se realiz�� siguiendo la metodolog��a de Dise��o Orientado a Objetivos. El objetivo de la evaluaci��n consist��a en investigar el efecto que tiene un servicio basado en el modelo de lazo cerrado sobre el estado de salud de los pacientes con insuficiencia card��aca. La evaluaci��n se realiz�� en el marco de un estudio cl��nico observacional. El an��lisis de los resultados ha comprendido m��todos de an��lisis cuantitativos y cualitativos. El an��lisis cuantitativo se ha centrado en determinar el estado de salud de los pacientes en base a datos objetivos (obtenidos en pruebas de laboratorio o ex��menes m��dicos). Para realizar este an��lisis se definieron dos ��ndices espec��ficos: el ��ndice de estabilidad y el ��ndice de la evoluci��n del estado de salud. El an��lisis cualitativo ha evaluado la autopercepci��n del estado de salud de los pacientes en t��rminos de calidad de vida, auto-cuidado, el conocimiento, la ansiedad y la depresi��n, as�� como niveles de conocimiento. Se ha basado en los datos recogidos mediante varios cuestionarios o instrumentos est��ndar (i.e. EQ-5D, la Escala de Ansiedad y Depresi��n (HADS), el Cuestionario de Cardiomiopat��a de Kansas City (KCCQ), la Escala Holandesa de Conocimiento de Insuficiencia Card��aca (DHFKS), y la Escala Europea de Autocuidado en Insuficiencia Card��aca (EHFScBS), as�� como cuestionarios dedicados no estandarizados de experiencia de usuario. Los resultados obtenidos en ambos an��lisis, cuantitativo y cualitativo, se compararon con el fin de evaluar la correlaci��n entre el estado de salud objetivo y subjetivo de los pacientes. Los resultados de la validaci��n demostraron que el modelo propuesto tiene efectos positivos en el cuidado de los pacientes con insuficiencia card��aca y contribuye a mejorar su estado de salud. Asimismo, ratificaron al modelo como instrumento v��lido para la definici��n de servicios mejorados para la gesti��n de esta enfermedad. ABSTRACT During the last decades we have witnessed a global aging phenomenon in the population. This can be observed in practically every country in the world, and it is mainly caused by the advances in medicine, and the decrease of mortality and fertility rates. Population aging has an important impact on citizens��� health and it is often the cause for chronic diseases, which constitute global burden and threat to the society in terms of mortality and healthcare expenditure. Among chronic diseases, Chronic Heart Failure (CHF) or Heart Failure (HF) is probably the one with highest prevalence, affecting between 23 and 26 million people worldwide. Heart failure is a chronic, long-term and serious condition with very poor prognosis and worse survival rates than some type of cancers. Additionally, it is often the cause of frequent hospitalizations and one of the most expensive conditions for the healthcare systems. The aging trends in the population and the increasing incidence of chronic diseases are leading to a situation where healthcare systems are not able to cope with the society demand. Current healthcare services will have to be adapted and redefined in order to be effective and sustainable in the future. There is a need to find new paradigms for patients��� care, and to identify new mechanisms for services��� provision that help to transform the healthcare systems. In this context, this thesis aims to explore new solutions, based on ICT, that contribute to achieve the needed transformation within the healthcare systems. In particular, it focuses on addressing the problems of one of the diseases with higher impact within these systems: Heart Failure. The following hypotheses represent the basis to the elaboration of this research: 1. It is possible to define a model based on a closed-loop paradigm and ICT tools that formalises the design of enhanced healthcare services for chronic heart failure patients. 2. The described closed-loop model can be exemplified in a real service that supports the management of chronic heart failure disease. 3. The introduction, adoption and use of a service based on the outlined model will result in improvements in the health status of patients suffering heart failure. 4. The user experience of patients when utilizing a system based on the defined closed-loop model will be enhanced. The definition of the closed-loop model for health care support of heart failure patients have been based on the standard ISO/EN 13940 System of concepts to support continuity of care. It includes a set of concept, processes and workflows, and services as main components, and it represent a formalization of services for heart failure patients. In order to be validated, the proposed closed-loop model has been instantiated into a real service and a supporting IT system. The design and implementation of the system followed the user centred design methodology Goal Oriented Design. The validation, that included an observational clinical study, aimed to investigate the effect that a service based on the closed-loop model had on heart failure patients��� health status. The analysis of results comprised quantitative and qualitative analysis methods. The quantitative analysis was focused on determining the health status of patients based on objective data (obtained in lab tests or physical examinations). Two specific indexes where defined and considered in this analysis: the stability index and the health status evolution index. The qualitative analysis assessed the self-perception of patients��� health status in terms of quality of life, self-care, knowledge, anxiety and depression, as well as knowledge levels. It was based on the data gathered through several standard instruments (i.e. EQ-5D, the Hospital Anxiety and Depression Scale, the Kansas City Cardiomyopathy Questionnaire, the Dutch Heart Failure Knowledge Scale, and the European Heart Failure Self-care Behaviour Scale) as well as dedicated non-standardized user experience questionnaires. The results obtained in both analyses, quantitative and qualitative, were compared in order to assess the correlation between the objective and subjective health status of patients. The results of the validation showed that the proposed model contributed to improve the health status of the patients and had a positive effect on the patients��� care. It also proved that the model is a valid instrument for designing enhanced healthcare services for heart failure patients.

A technological framework based on automatic messaging for improving adherence of diabetic patients

En todo el mundo se ha observado un crecimiento exponencial en la incidencia de enfermedades cr��nicas como la hipertensi��n y enfermedades cardiovasculares y respiratorias, as�� como la diabetes mellitus, que causa un n��mero de muertes cada vez mayor en todo el mundo (Beaglehole et al., 2008). En concreto, la prevalencia de diabetes mellitus (DM) est�� aumentando de manera considerable en todas las edades y representa un serio problema de salud mundial. La diabetes fue la responsable directa de 1,5 millones de muertes en 2012 y 89 millones de a��os de vida ajustados por discapacidad (AVAD) (OMS, 2014). Uno de los principales dilemas que suelen asociarse a la gesti��n de EC es la adherencia de los pacientes a los tratamientos, que representa un aspecto multifactorial que necesita asistencia en lo relativo a: educaci��n, autogesti��n, interacci��n entre los pacientes y cuidadores y compromiso de los pacientes. Medir la adherencia del tratamiento es complicado y, aunque se ha hablado ampliamente de ello, a��n no hay soluciones ���de oro��� (Reviews, 2002). El compromiso de los pacientes, a trav��s de la participaci��n, colaboraci��n, negociaci��n y a veces del compromiso firme, aumentan las oportunidades para una terapia ��ptima en la que los pacientes se responsabilizan de su parte en la ecuaci��n de adherencia. Comprometer e involucrar a los pacientes diab��ticos en las decisiones de su tratamiento, junto con expertos profesionales, puede ayudar a favorecer un enfoque centrado en el paciente hacia la atenci��n a la diabetes (Martin et al., 2005). La motivaci��n y atribuci��n de poder de los pacientes son quiz��s los dos factores interventores m��s relevantes que afectan directamente a la autogesti��n de la atenci��n a la diabetes. Se ha demostrado que estos dos factores desempe��an un papel fundamental en la adherencia a la prescripci��n, as�� como en el fomento exitoso de un estilo de vida sana y otros cambios de conducta (Heneghan et al., 2013). Un plan de educaci��n personalizada es indispensable para proporcionarle al paciente las herramientas adecuadas que necesita para la autogesti��n efectiva de la enfermedad (El-Gayar et al. 2013). La comunicaci��n efectiva es fundamental para proporcionar una atenci��n centrada en el paciente puesto que influye en las conductas y actitudes hacia un problema de salud ((Frampton et al. 2008). En este sentido, la interactividad, la frecuencia, la temporalizaci��n y la adaptaci��n de los mensajes de texto pueden promover la adherencia a un r��gimen de medicaci��n. Como consecuencia, adaptar los mensajes de texto a los pacientes puede resultar ser una manera de hacer que las sugerencias y la informaci��n sean m��s relevantes y efectivas (Nundy et al. 2013). En este contexto, las tecnolog��as m��viles en el ��mbito de la salud (mHealth) est��n desempe��ando un papel importante al conectar con pacientes para mejorar la adherencia a medicamentos recetados (Krishna et al., 2009). La adaptaci��n de los mensajes de texto espec��ficos de diabetes sigue siendo un ��rea de oportunidad para mejorar la adherencia a la medicaci��n y ofrecer motivaci��n a adultos con diabetes. Sin embargo, se necesita m��s investigaci��n para entender totalmente su eficacia. Los consejos de texto personalizados han demostrado causar un impacto positivo en la atribuci��n de poder a los pacientes, su autogesti��n y su adherencia a la prescripci��n (Gatwood et al., 2014). mHealth se puede utilizar para ofrecer programas de asistencia de autogesti��n a los pacientes con diabetes y, al mismo tiempo, superar las dificultades t��cnicas y financieras que supone el tratamiento de la diabetes (Free at al., 2013). El objetivo principal de este trabajo de investigaci��n es demostrar que un marco tecnol��gico basado en las teor��as de cambios de conducta, aplicado al campo de la mHealth, permite una mejora de la adherencia al tratamiento en pacientes diab��ticos. Como m��todo de definici��n de una soluci��n tecnol��gica, se han adoptado un conjunto de diferentes t��cnicas de conducta validadas denominado marco de compromiso de retroacci��n conductual (EBF, por sus siglas en ingl��s) para formular los mensajes, guiar el contenido y evaluar los resultados. Los estudios incorporan elementos del modelo transte��rico (TTM, por sus siglas en ingl��s), la teor��a de la fijaci��n de objetivos (GST, por sus siglas en ingl��s) y los principios de comunicaci��n sanitaria persuasiva y eficaz. Como concepto general, el modelo TTM ayuda a los pacientes a progresar a su pr��xima fase de conducta a trav��s de mensajes de texto motivados espec��ficos y permite que el m��dico identifique la fase actual y adapte sus estrategias individualmente. Adem��s, se adoptan las directrices del TTM para fijar objetivos personalizados a un nivel apropiado a la fase de cambio del paciente. La GST encierra normas que van a ponerse en pr��ctica para promover la intervenci��n educativa y objetivos de p��rdida de peso. Finalmente, los principios de comunicaci��n sanitaria persuasiva y eficaz aplicados a la aparici��n de los mensajes se han puesto en marcha para aumentar la efectividad. El EBF tiene como objetivo ayudar a los pacientes a mejorar su adherencia a la prescripci��n y encaminarlos a una mejora general en la autogesti��n de la diabetes mediante mensajes de texto personalizados denominados mensajes de retroacci��n autom��ticos (AFM, por sus siglas en ingl��s). Despu��s de una primera revisi��n del perfil, consistente en identificar caracter��sticas significativas del paciente basadas en las necesidades de tratamiento, actitudes y conductas de atenci��n sanitaria, el sistema elige los AFM personalizados, los aprueba el m��dico y al final se transfieren a la interfaz del paciente. Durante el tratamiento, el usuario recopila los datos en dispositivos de monitorizaci��n de pacientes (PMD, por sus siglas en ingl��s) de una serie de dispositivos m��dicos y registros manuales. Los registros consisten en la toma de medicaci��n, dieta y actividad f��sica y tareas de aprendizaje y control de la medida del metabolismo. El compromiso general del paciente se comprueba al estimar el uso del sistema y la adherencia del tratamiento y el estado de los objetivos del paciente a corto y largo plazo. El m��dulo de an��lisis conductual, que consiste en una serie de reglas y ecuaciones, calcula la conducta del paciente. Tras lograr el an��lisis conductual, el m��dulo de gesti��n de AFM actualiza la lista de AFM y la configuraci��n de los env��os. Las actualizaciones incluyen el n��mero, el tipo y la frecuencia de mensajes. Los AFM los revisa peri��dicamente el m��dico que tambi��n participa en el perfeccionamiento del tratamiento, adaptado a la fase transte��rica actual. Los AFM se segmentan en distintas categor��as y niveles y los pacientes pueden ajustar la entrega del mensaje de acuerdo con sus necesidades personales. El EBF se ha puesto en marcha integrado dentro del sistema METABO, dise��ado para facilitar al paciente diab��tico que controle sus condiciones relevantes de una manera menos intrusiva. El dispositivo del paciente se vincula en una plataforma m��vil, mientras que una interfaz de panel m��dico permite que los profesionales controlen la evoluci��n del tratamiento. Herramientas espec��ficas posibilitan que los profesionales comprueben la adherencia del paciente y actualicen la gesti��n de env��os de AFM. El EBF fue probado en un proyecto piloto controlado de manera aleatoria. El principal objetivo era examinar la viabilidad y aceptaci��n del sistema. Los objetivos secundarios eran tambi��n la evaluaci��n de la eficacia del sistema en lo referente a la mejora de la adherencia, el control gluc��mico y la calidad de vida. Se reclutaron participantes de cuatro centros cl��nicos distintos en Europa. La evaluaci��n del punto de referencia inclu��a datos demogr��ficos, estado de la diabetes, informaci��n del perfil, conocimiento de la diabetes en general, uso de las plataformas TIC, opini��n y experiencia con dispositivos electr��nicos y adopci��n de buenas pr��cticas con la diabetes. La aceptaci��n y eficacia de los criterios de evaluaci��n se aplicaron para valorar el funcionamiento del marco tecnol��gico. El principal objetivo era la valoraci��n de la eficacia del sistema en lo referente a la mejora de la adherencia. En las pruebas participaron 54 pacientes. 26 fueron asignados al grupo de intervenci��n y equipados con tecnolog��a m��vil donde estaba instalado el EBF: 14 pacientes ten��an T1DM y 12 ten��an T2DM. El grupo de control estaba compuesto por 25 pa cientes que fueron tratados con atenci��n est��ndar, sin el empleo del EBF. La intervenci��n profesional tanto de los grupos de control como de intervenci��n corri�� a cargo de 24 cuidadores, entre los que inclu��an diabet��logos, nutricionistas y enfermeras. Para evaluar la aceptabilidad del sistema y analizar la satisfacci��n de los usuarios, a trav��s de LimeSurvey, se cre�� una encuesta multiling��e tanto para los pacientes como para los profesionales. Los resultados tambi��n se recopilaron de los archivos de registro generados en los PMD, el panel m��dico profesional y las entradas de la base de datos. Los mensajes enviados hacia y desde el EBF y los archivos de registro del sistema y los servicios de comunicaci��n se grabaron durante las cinco semanas del estudio. Se entregaron un total de 2795 mensajes, lo que supuso una media de 107,50 mensajes por paciente. Como se muestra, los mensajes disminuyen con el tiempo, indicando una mejora global de la adherencia al plan de tratamiento. Como se esperaba, los pacientes con T1DM recibieron m��s consejos a corto plazo, en relaci��n a su estado. Del mismo modo, al ser el centro de T2DM en cambios de estilo de vida sostenible a largo plazo, los pacientes con T2DM recibieron m��s consejos de recomendaci��n, en cuanto a dietas y actividad f��sica. Tambi��n se ha llevado a cabo una comparaci��n de la adherencia e ��ndices de uso para pacientes con T1DM y T2DM, entre la primera y la segunda mitad de la prueba. Se han observado resultados favorables para el uso. En lo relativo a la adherencia, los resultados denotaron una mejora general en cada dimensi��n del plan de tratamiento, como la nutrici��n y las mediciones de inserci��n de glucosa en la sangre. Se han llevado a cabo m��s estudios acerca del cambio a nivel educativo antes y despu��s de la prueba, medidos tanto para grupos de control como de intervenci��n. Los resultados indicaron que el grupo de intervenci��n hab��a mejorado su nivel de conocimientos mientras que el grupo de control mostr�� una leve disminuci��n. El an��lisis de correlaci��n entre el nivel de adherencia y las AFM ha mostrado una mejora en la adherencia de uso para los pacientes que recibieron los mensajes de tipo alertas, y unos resultados no significativos aunque positivos relacionados con la adherencia tanto al tratamiento que al uso correlacionado con los recordatorios. Por otra parte, los AFM parec��an ayudar a los pacientes que no tomaban suficientemente en serio su tratamiento en el principio y que s�� estaban dispuestos a responder a los mensajes recibidos. Aun as��, los pacientes que recibieron demasiadas advertencias, comenzaron a considerar el env��o de mensajes un poco estresante. El trabajo de investigaci��n llevado a cabo al desarrollar este proyecto ofrece respuestas a las cuatro hip��tesis de investigaci��n que fueron la motivaci��n para el trabajo. ��� Hip��tesis 1 : es posible definir una serie de criterios para medir la adherencia en pacientes diab��ticos. ��� Hip��tesis 2: es posible dise��ar un marco tecnol��gico basado en los criterios y teor��as de cambio de conducta mencionados con anterioridad para hacer que los pacientes diab��ticos se comprometan a controlar su enfermedad y adherirse a planes de atenci��n. ��� Hip��tesis 3: es posible poner en marcha el marco tecnol��gico en el sector de la salud m��vil. ��� Hip��tesis 4: es posible utilizar el marco tecnol��gico como soluci��n de salud m��vil en un contexto real y tener efectos positivos en lo referente a indicadores de control de diabetes. La verificaci��n de cada hip��tesis permite ofrecer respuesta a la hip��tesis principal: La hip��tesis principal es: es posible mejorar la adherencia diab��tica a trav��s de un marco tecnol��gico mHealth basado en teor��as de cambio de conducta. El trabajo llevado a cabo para responder estas preguntas se explica en este trabajo de investigaci��n. El marco fue desarrollado y puesto en pr��ctica en el Proyecto METABO. METABO es un Proyecto I+D, cofinanciado por la Comisi��n Europea (METABO 2008) que integra infraestructura m��vil para ayudar al control, gesti��n y tratamiento de los pacientes con diabetes mellitus de tipo 1 (T1DM) y los que padecen diabetes mellitus de tipo 2 (T2DM). ABSTRACT Worldwide there is an exponential growth in the incidence of Chronic Diseases (CDs), such as: hypertension, cardiovascular and respiratory diseases, as well as diabetes mellitus, leading to rising numbers of deaths worldwide (Beaglehole et al. 2008). In particular, the prevalence of diabetes mellitus (DM) is largely increasing among all ages and constitutes a major worldwide health problem. Diabetes was directly responsible for 1,5 million deaths in 2012 and 89 million Disability-adjusted life year (DALYs) (WHO 2014). One of the key dilemmas often associated to CD management is the patients��� adherence to treatments, representing a multi-factorial aspect that requires support in terms of: education, self-management, interaction between patients and caregivers, and patients��� engagement. Measuring adherence is complex and, even if widely discussed, there are still no ���gold��� standards ((Giardini et al. 2015), (Costa et al. 2015). Patient���s engagement, through participation, collaboration, negotiation, and sometimes compromise, enhance opportunities for optimal therapy in which patients take responsibility for their part of the adherence equation. Engaging and involving diabetic patients in treatment decisions, along with professional expertise, can help foster a patient-centered approach to diabetes care (Martin et al. 2005). Patients��� motivation and empowerment are perhaps the two most relevant intervening factors that directly affect self-management of diabetes care. It has been demonstrated that these two factors play an essential role in prescription adherence, as well as for the successful encouragement of a healthy life-style and other behavioural changes (Heneghan et al. 2013). A personalised education plan is indispensable in order to provide the patient with the appropriate tools needed for the effective self-management of the disease (El-Gayar et al. 2013). Effective communication is at the core of providing patient-centred care since it influences behaviours and attitudes towards a health problem (Frampton et al. 2008). In this regard, interactivity, frequency, timing, and tailoring of text messages may promote adherence to a medication regimen. As a consequence, tailoring text messages to patients can constitute a way of making suggestions and information more relevant and effective (Nundy et al. 2013). In this context, mobile health technologies (mHealth) are playing significant roles in improving adherence to prescribed medications (Krishna et al. 2009). The tailoring of diabetes-specific text messages remains an area of opportunity to improve medication adherence and provide motivation to adults with diabetes but further research is needed to fully understand their effectiveness. Personalized text advices have proven to produce a positive impact on patients��� empowerment, self-management, and adherence to prescriptions (Gatwood et al. 2014). mHealth can be used for offering self-management support programs to diabetes patients and at the same time surmounting the technical and financial difficulties involved in diabetes treatment (Free et al. 2013). The main objective of this research work is to demonstrate that a technological framework, based on behavioural change theories, applied to mHealth domain, allows improving adherence treatment in diabetic patients. The framework, named Engagement Behavioural Feedback Framework (EBF), is built on top of validated behavioural techniques to frame messages, guide the definition of contents and assess outcomes: elements from the Transtheoretical Model (TTM), the Goal-Setting Theory (GST), Effective Health Communication (EHC) guidelines and Principles of Persuasive Technology (PPT) were incorporated. The TTM helps patients to progress to a next behavioural stage, through specific motivated text messages, and allow clinician���s identifying the current stage and tailor its strategies individually. Moreover, TTM guidelines are adopted to set customised goals at a level appropriate to the patient���s stage of change. The GST was used to build rules to be applied for enhancing educational intervention and weight loss objectives. Finally, the EHC guidelines and the PPT were applied to increase the effectiveness of messages. The EBF aims to support patients on improving their prescription adherence and persuade them towards a general improvement in diabetes self-management, by means of personalised text messages, named Automatic Feedback Messages (AFM). After a first profile screening, consisting in identifying meaningful patient characteristics based on treatment needs, attitudes and health care behaviours, customised AFMs are selected by the system, approved by the professional, and finally transferred into the patient interface. During the treatment, the user collects the data into a Patient Monitoring Device (PMD) from a set of medical devices and from manual inputs. Inputs consist in medication intake, diet and physical activity, metabolic measurement monitoring and learning tasks. Patient general engagement is checked by estimating the usage of the system and the adherence of treatment and patient goals status in the short and the long term period. The Behavioural Analysis Module, consisting in a set of rules and equations, calculates the patient���s behaviour. After behavioural analysis is accomplished, the AFM library and the dispatch setting are updated by the AFM Manager module. Updates include the number, the type and the frequency of messages. The AFMs are periodically supervised by the professional who also participates to the refinement of the treatment, adapted to the current transtheoretical stage. The AFMs are segmented in different categories and levels and patients can adjust message delivery in accordance with their personal needs. The EBF was integrated to the METABO system, designed to facilitate diabetic patients in managing their disease in a less intrusive approach. Patient device corresponds in a mobile platform, while a medical panel interface allows professionals to monitoring the treatment evolution. Specific tools allow professional to check patient adherence and to update the AFMs dispatch management. The EBF was tested in a randomised controlled pilot. The main objective was to examine the feasibility and acceptance of the system. Secondary objectives were also the assessment of the effectiveness of system in terms of adherence improvement, glycaemic control, and quality of life. Participants were recruited from four different clinical centres in Europe. The baseline assessment included demographics, diabetes status, profile information, knowledge about diabetes in general, usage of ICT platforms, opinion and experience about electronic devices and adoption of good practices with diabetes. Acceptance and the effectiveness evaluation criteria were applied to evaluate the performance of the technological framework. The main objective was the assessment of the effectiveness of system in terms of adherence improvement. Fifty-four patients participated on the trials. Twenty-six patients were assigned in the intervention group and equipped with mobile where the EBF was installed: 14 patients were T1DM and 12 were T2DM. The control group was composed of 25 patients that were treated through a standard care, without the usage of the EBF. Professional���s intervention for both intervention and control groups was carried out by 24 care providers, including endocrinologists, nutritionists, and nurses. In order to evaluate the system acceptability and analyse the users��� satisfaction, an online multi-language survey, using LimeSurvey, was produced for both patients and professionals. Results were also collected from the log-files generated in the PMDs, the professional medical panel and the entries of the data base. The messages sent to and from the EBF and the log-files of the system and communication services were recorded over 5 weeks of the study. A total of 2795 messages were submitted, representing an average of 107,50 messages per patient. As demonstrated, messages decrease over time indicating an overall improvement of the care plan���s adherence. As expected, T1DM patients were more loaded with short-term advices, in accordance with their condition. Similarly, being the focus of T2DM on long-term sustainable lifestyle changes, T2DM received more reminders advices, as for diet and physical activity. Favourable outcomes were observed for treatment and usage adherences of the intervention group: for both the adherence indices, results denoted a general improvement on each care plan���s dimension, such as on nutrition and blood glucose input measurements. Further studies were conducted on the change on educational level before and after the trial, measured for both control and intervention groups. The outcomes indicated the intervention group has improved its level of knowledge, while the control group denoted a low decrease. The correlation analysis between the level of adherences and the AFMs showed an improvement in usage adherence for patients who received warnings message, while non-significantly yet even positive indicators related to both treatment and usage adherence correlated with the Reminders. Moreover, the AFMs seemed to help those patients who did not take their treatment seriously enough in the beginning and who were willing to respond to the messages they received. Even though, patients who received too many Warnings, started to consider the message dispatch to be a bit stressful. The research work carried out in developing this research work provides responses to the four research hypothesis that were the motivation for the work: ������Hypothesis 1: It is possible to define a set of criteria to measure adherence in diabetic patients. ������Hypothesis 2: It is possible to design a technological framework, based on the aforementioned criteria and behavioural change theories, to engage diabetic patients in managing their disease and adhere to care plans. ������Hypothesis 3: It is possible to implement the technological framework in the mobile health domain. ������Hypothesis 4: It is possible to use the technological framework as a mobile health solution in a real context and have positive effects in terms of diabetes management indicators. The verification of each hypothesis allowed us to provide a response to the main hypothesis: The Main Hypothesis is: It is possible to improve diabetic adherence through a mHealth technological framework based on behavioural change theories. The work carried out to answer these questions is explained in this research work. The framework was developed and applied in the METABO project. METABO is an R&D project, co-funded by the European Commission (METABO 2008) that integrates mobile infrastructure for supporting the monitoring, management, and treatment of type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) patients.

La Pen��nsula Ib��rica en el transporte masivo de mercanc��as entre Europa y ��frica : futuras autopistas del mar

La competitividad del transporte de mercanc��as depende del estado y funcionamiento de las redes existentes y de sus infraestructuras, no del modo de transporte. En concreto, la rentabilidad o la reducci��n de los costes de producci��n del transporte mar��timo se ver��a incrementado con el uso de buques de mayor capacidad y con el desarrollo de plataformas portuarias de distribuci��n o puertos secos, ya que el 90% del comercio entre la Uni��n Europea y terceros pa��ses se realiza a trav��s de sus puertos a un promedio de 3,2 billones de toneladas de mercanc��as manipuladas cada a��o y el 40% del tr��fico intraeuropeo utiliza el transporte mar��timo de corta distancia. A pesar de que los puertos europeos acogen anualmente a m��s de 400 millones de pasajeros, los grandes desarrollos se han producido en los puertos del norte de Europa (R��terdam, Amberes, ��msterdam). Los pa��ses del Sur de Europa deben buscar nuevas f��rmulas para ser m��s competitivos, ya sea mediante creaci��n de nuevas infraestructuras o mediante refuerzo de las existentes, ofreciendo los costes de los puertos del Norte. El fomento del transporte mar��timo y fluvial como alternativa al transporte por carretera, especialmente el transporte mar��timo de corta distancia, ha sido impulsado por la Comisi��n Europea (CE) desde 2003 a trav��s de programas de apoyo comunitario de aplicaci��n directa a las Autopistas del Mar, a modo de ejemplo, cabr��a citar los programas Marco Polo I y II, los cuales contaron con una dotaci��n presupuestaria total de 855 millones de euros para el per��odo 2003 ��� 2013; en ese per��odo de tiempo se establecieron objetivos de reducci��n de congesti��n vial y mejora del comportamiento medio ambiental del sistema de transporte de mercanc��as dentro de la comunidad y la potenciaci��n de la intermodalidad. El concepto de Autopista del Mar surge en el Libro Blanco de Transportes de la Comisi��n Europea ���La pol��tica europea de transportes de cara al 2010: La hora de la verdad��� del 12 de diciembre de 2001, en el marco de una pol��tica europea para fomento y desarrollo de sistemas de transportes sostenibles. Las Autopistas del Mar consisten en rutas mar��timas de corta distancia entre dos puntos, de menor distancia que por v��a terrestre, en las que a trav��s del transporte intermodal mejoran significativamente los tiempos y costes de la cadena log��stica, contribuyen a la reducci��n de accidentes, ruidos y emisiones de CO2 a la atm��sfera, permite que los conductores pierdan horas de trabajo al volante y evita el deterioro de las infraestructuras terrestres, con el consiguiente ahorro en mantenimiento. La viabilidad de una Autopista del Mar depende tanto de factores de ubicaci��n geogr��ficos, como de caracter��sticas propias del puerto, pasando por los diferentes requerimientos del mercado en cada momento (energ��ticos, medio ambientales y tecnol��gicos). Existe un elemento nuevo creado por la Comisi��n Europea: la red transeuropea de transportes (RTE-T). En el caso de Espa��a, con sus dos accesos por los Pirineos (La Junquera e Ir��n) como ��nicos pasos terrestres de comunicaci��n con el continente y con importantes limitaciones ferroviarias debido a los tres anchos de v��a distintos, le resta competitividad frente al conjunto europeo; por el contrario, Espa��a es el pa��s europeo con m��s kil��metros de costa (con m��s de 8.000 km) y con un emplazamiento geogr��fico estrat��gico, lo que le convierte en una plataforma log��stica para todo el sur de Europa, por lo que las Autopistas del Mar tendr��n un papel importante y casi obligado para el desarrollo de los grandes corredores mar��timos que promueve Europa. De hecho, Gij��n y Vigo lo han hecho muy bien con sus respectivas l��neas definidas como Autopistas del Mar y que conectan con el puerto franc��s de Nantes-Saint Nazaire, ya que desde ah�� los camiones pueden coger rutas hacia el Norte. Paralelamente, la Uni��n Europea ha iniciado los pasos para el impulso de la primera Autopista del Mar que conectar�� Espa��a con el mercado de Reino Unido, concretamente los Puertos de Bilbao y Tilbury. Adem��s, Espa��a e Italia sellaron un acuerdo internacional para desarrollar Autopistas del Mar entre ambos pa��ses, comprometi��ndose a impulsar una docena de rutas entre puertos del litoral mediterr��neo espa��ol y el italiano. Actualmente, est��n en funcionando los trayectos como Barcelona-G��nova, Valencia-Civitavecchia y Alicante- N��poles, notablemente m��s cortos por mar que por carretera. Bruselas identific�� cuatro grandes corredores mar��timos que podr��an concentrar una alta densidad de tr��fico de buques, y en dos de ellos Espa��a ya ten��a desde un principio un papel crucial. La Comisi��n dise���� el 14 de abril de 2004, a trav��s del proyecto West-Mos, una red de tr��fico mar��timo que tiene como v��as fundamentales la denominada Autopista del B��ltico (que enlaza Europa central y occidental con los pa��ses b��lticos), la Autopista de Europa suroriental (que une el Adri��tico con el J��nico y el Mediterr��neo m��s oriental) y tambi��n la Autopista de Europa occidental y la Autopista de Europa suroccidental (que enlazan Espa��a con Reino Unido y la Francia atl��ntica y con la Francia mediterr��nea e Italia, respectivamente). Para poder establecer Autopistas del Mar entre la Pen��nsula Ib��rica y el Norte de Europa primar�� especialmente la retirada de camiones en la frontera pirenaica, donde el tr��fico pesado tiene actualmente una intensidad media diaria de 8.000 unidades, actuando sobre los puntos de mayor congesti��n, como por ejemplo los Alpes, los Pirineos, el Canal de la Mancha, las carreteras fronterizas de Francia y Euskadi, y proponiendo el traslado de las mercanc��as en barcos o en trenes. Por su parte, para contar con los subsidios y apoyos europeos las rutas seleccionadas como Autopistas del Mar deben mantener una serie de criterios de calidad relacionados con la frecuencia, coste ���plataforma log��stica a plataforma log��stica���, simplicidad en procedimientos administrativos y participaci��n de varios pa��ses, entre otros. Los estudios consideran inicialmente viables los tramos mar��timos superiores a 450 millas, con un volumen de unas 15.000 plataformas al a��o y que dispongan de eficientes comunicaciones desde el puerto a las redes transeuropeas de autopistas y ferrocarril. Otro objetivo de las Autopistas del Mar es desarrollar las capacidades portuarias de forma que se puedan conectar mejor las regiones perif��ricas a escala del continente europeo. En lo que a Puertos se refiere, las terminales en los muelles deben contar con una l��nea de atraque de 250 m., un calado superior a 8 m., una rampa ���ro-ro��� de doble calzada, gr��as portainer, y garantizar operatividad para un m��nimo de dos frecuencias de carga semanales. El 28 de marzo de 2011 se public�� el segundo Libro Blanco sobre el futuro del transporte en Europa ���Hoja de ruta hacia un espacio ��nico europeo de transporte: por una pol��tica de transportes competitiva y sostenible���, donde se defini�� el marco general de las acciones a emprender en los pr��ximos diez a��os en el ��mbito de las infraestructuras de transporte, la legislaci��n del mercado interior, la reducci��n de la dependencia del carbono, la tecnolog��a para la gesti��n del tr��fico y los veh��culos limpios, as�� como la estandarizaci��n de los distintos mercados. Entre los principales desaf��os se encuentran la eliminaci��n de los cuellos de botella y obst��culos diversos de nuestra red europea de transporte, minimizar la dependencia del petr��leo, reducir las emisiones de GEI en un 60% para 2050 con respecto a los niveles de 1990 y la inversi��n en nuevas tecnolog��as e infraestructuras que reduzcan estas emisiones de transporte en la UE. La conexi��n entre la UE y el norte de ��frica provoca elevados niveles de congesti��n en los puntos m��s cr��ticos del trayecto: frontera hispano-francesa, corredor del Mediterr��neo y el paso del estrecho. A esto se le a��ade el hecho de que el sector del transporte por carretera est�� sujeto a una creciente competencia de mercado motivada por la eliminaci��n de las barreras europeas, mayores exigencias de los cargadores, mayores restricciones a los conductores y aumento del precio del gas��leo. Por otro lado, el mercado potencial de pasajeros tiene una clara diferenciaci��n en tipos de flujos: los flujos en el per��odo extraordinario de la Operaci��n Paso del Estrecho (OPE), enfocado principalmente a marroqu��es que vuelven a su pa��s de vacaciones; y los flujos en el per��odo ordinario, enfocado a la movilidad global de la poblaci��n. Por tanto, lo que se pretende conseguir con este estudio es analizar la situaci��n actual del tr��fico de mercanc��as y pasajeros con origen o destino la pen��nsula ib��rica y sus causas, as�� como la investigaci��n de las ventajas de la creaci��n de una conexi��n mar��tima (Autopista del Mar) con el Norte de ��frica, bas��ndose en los condicionantes t��cnicos, administrativos, econ��micos, pol��ticos, sociales y medio ambientales. The competitiveness of freight transport depends on the condition and operation of existing networks and infrastructure, not the mode of transport. In particular, profitability could be increased or production costs of maritime transport could be reduced by using vessels with greater capacity and developing port distribution platforms or dry ports, seeing as 90% of trade between the European Union and third countries happens through its ports. On average 3,2 billion tonnes of freight are handled annualy and 40% of intra-European traffic uses Short Sea Shipping. In spite of European ports annually hosting more than 400 million passengers, there have been major developments in the northern European ports (Rotterdam, Antwerp, Amsterdam). Southern European countries need to find new ways to be more competitive, either by building new infrastructure or by strengthening existing infrastructure, offering costs northern ports. The use of maritime and river transport as an alternative to road transport, especially Short Sea Shipping, has been driven by the European Commission (EC) from 2003 through community support programs for the Motorways of the Sea. These programs include, for example, the Marco Polo I and II programs, which had a total budget of 855 million euros for the period 2003-2013. During this time objectives were set for reducing road congestion, improving the environmental performance of the freight transport system within the community and enhancing intermodal transport. The ���Motorway of the Sea��� concept arises in the European Commission���s Transport White Paper "European transport policy for 2010: time to decide" on 12 December 2001, as part of a European policy for the development and promotion of sustainable transport systems. A Motorway of the Sea is defined as a short sea route between two points, covering less distance than by road, which provides a significant improvement in intermodal transport times and to the cost supply chain. It contributes to reducing accidents, noise and CO2 emissions, allows drivers to shorten their driving time and prevents the deterioration of land infrastructure thereby saving on maintenance costs. The viability of a Motorway of the Sea depends as much on geographical location factors as on characteristics of the port, taking into account the different market requirements at all times (energy, environmental and technological). There is a new element created by the European Commission: the trans-European transport network (TEN-T). In the case of Spain, with its two access points in the Pyrenees (La Junquera and Irun) as the only land crossings connected to the mainland and major railway limitations due to the three different gauges, it appears less competitive compared to Europe as a whole. However, Spain is the European country with the most kilometers of coastline (over 8,000 km) and a strategic geographical location, which makes it a logistics platform for the all of Southern Europe. This is why the Motorways of the Sea will have an important role, and an almost necessary one to develop major maritime corridors that Europe supports. In fact, Gijon and Vigo have done very well with their respective sea lanes defined as Motorways of the Sea and which connect with the French port of Nantes-Saint Nazaire, as from there trucks can use nort-heading routes. In parallel, the European Union has taken the first steps to boost the first Motorway of the Sea linking Spain to the UK market, specifically the ports of Bilbao and Tilbury. Furthermore, Spain and Italy sealed an international agreement to develop Motorways of the Sea between both countries, pledging to develop a dozen routes between ports on the Spanish and Italian Mediterranean coasts. Currently, there are sea lanes already in use such as Barcelona-Genova, Valencia-Civitavecchia and Alicante-Naples, these are significantly shorter routes by sea than by road. Brussels identified four major maritime corridors that could hold heavy concentrate shipping traffic, and Spain had a crucial role in two of these from the beginning. On 14 April 2004 the Commission planned through the West-Mos project, a network of maritime traffic which includes the essential sea passages the so-called Baltic Motorway (linking Central and Western Europe with the Baltic countries), the southeast Europe Motorway (linking the Adriatic to the Ionian and eastern Mediterranean Sea), the Western Europe Motorway and southwestern Europe Motorway (that links Spain with Britain and the Atlantic coast of France and with the French Mediterranean coast and Italy, respectively). In order to establish Motorways of the Sea between the Iberian Peninsula and Northern Europe especially, it is necessary to remove trucks from the Pyrenean border, where sees heavy traffic (on average 8000 trucks per day) and addressing the points of greatest congestion, such as the Alps, the Pyrenees, the English Channel, the border roads of France and Euskadi, and proposing the transfer of freight on ships or trains. For its part, in order to receive subsidies and support from the European Commission, the routes selected as Motorways of the Sea should maintain a series of quality criteria related to frequency, costs "from logistics platform to logistics platform," simplicity in administrative procedures and participation of several countries, among others. To begin with, studies consider viable a maritime stretch of at least 450 miles with a volume of about 15,000 platforms per year and that have efficient connections from port to trans-European motorways and rail networks. Another objective of the Motorways of the Sea is to develop port capacity so that they can better connect peripheral regions across the European continent. Referring ports, the terminals at the docks must have a berthing line of 250 m., a draft greater than 8 m, a dual carriageway "ro-ro" ramp, portainer cranes, and ensure operability for a minimum of two loads per week. On 28 March 2011 the second White Paper about the future of transport in Europe "Roadmap to a Single European Transport Area ��� Towards a competitive and resource efficient transport system" was published. In this Paper the general framework of actions to be undertaken in the next ten years in the field of transport infrastructure was defined, including internal market legislation, reduction of carbon dependency, traffic management technology and clean vehicles, as well as the standardization of different markets. The main challenges are how to eliminate bottlenecks and various obstacles in our European transport network, minimize dependence on oil, reduce GHG emissions by 60% by 2050 compared to 1990 levels and encourage investment in new technologies and infrastructure that reduce EU transport emissions. The connection between the EU and North Africa causes high levels of congestion on the most critical points of the journey: the Spanish-French border, the Mediterranean corridor and Gibraltar Strait. In addition to this, the road transport sector is subject to increased market competition motivated by the elimination of European barriers, greater demands of shippers, greater restrictions on drivers and an increase in the price of diesel. On the other hand, the potential passenger market has a clear differentiation in type of flows: flows in the special period of the Crossing the Straits Operation (CSO), mainly focused on Moroccans who return home on vacation; and flows in the regular session, focused on the global mobile population. Therefore, what I want to achieve with this study is present an analysis of the current situation of freight and passengers to or from the Iberian Peninsula and their causes, as well as present research on the advantages of creating a maritime connection (Motorways of the Sea) with North Africa, based on the technical, administrative, economic, political, social and environmental conditions.

Las Redes de Petri Interpretadas en el Diagn��stico de Fallos de Sistemas H��bridos. Aplicaci��n a un Helic��ptero no Tripulado

La seguridad y fiabilidad de los procesos industriales son la principal preocupaci��n de los ingenieros encargados de las plantas industriales. Por lo tanto, desde un punto de vista econ��mico, el objetivo principal es reducir el costo del mantenimiento, el tiempo de inactividad y las p��rdidas causadas por los fallos. Por otra parte, la seguridad de los operadores, que afecta a los aspectos sociales y econ��micos, es el factor m��s relevante a considerar en cualquier sistema Debido a esto, el diagn��stico de fallos se ha convertido en un foco importante de inter��s para los investigadores de todo el mundo e ingenieros en la industria. Los principales trabajos enfocados en detecci��n de fallos se basan en modelos de los procesos. Existen diferentes t��cnicas para el modelado de procesos industriales tales como m��quinas de estado, ��rboles de decisi��n y Redes de Petri (RdP). Por lo tanto, esta tesis se centra en el modelado de procesos utilizando redes de petri interpretadas. Redes de Petri es una herramienta usada en el modelado gr��fico y matem��tico con la habilidad para describir informaci��n de los sistemas de una manera concurrente, paralela, asincrona, distribuida y no determin��stica o estoc��stica. RdP son tambi��n una herramienta de comunicaci��n visual gr��fica ��til como lo son las cartas de flujo o diagramas de bloques. Adicionalmente, las marcas de las RdP simulan la din��mica y concurrencia de los sistemas. Finalmente, ellas tienen la capacidad de definir ecuaciones de estado espec��ficas, ecuaciones algebraicas y otros modelos que representan el comportamiento com��n de los sistemas. Entre los diferentes tipos de redes de petri (Interpretadas, Coloreadas, etc.), este trabajo de investigaci��n trata con redes de petri interpretadas principalmente debido a caracter��sticas tales como sincronizaci��n, lugares temporizados, aparte de su capacidad para procesamiento de datos. Esta investigaci��n comienza con el proceso para dise��ar y construir el modelo y diagnosticador para detectar fallos definitivos, posteriormente, la din��mica temporal fue adicionada para detectar fallos intermitentes. Dos procesos industriales, concretamente un HVAC (Calefacci��n, Ventilaci��n y Aire Acondicionado) y un Proceso de Envasado de L��quidos fueron usados como banco de pruebas para implementar la herramienta de diagn��stico de fallos (FD) creada. Finalmente, su capacidad de diagn��stico fue ampliada en orden a detectar fallos en sistemas h��bridos. Finalmente, un peque��o helic��ptero no tripulado fue elegido como ejemplo de sistema donde la seguridad es un desaf��o, y las t��cnicas de detecci��n de fallos desarrolladas en esta tesis llevan a ser una herramienta valorada, desde que los accidentes de las aeronaves no tripuladas (UAVs) envuelven un alto costo econ��mico y son la principal raz��n para introducir restricciones de volar sobre ��reas pobladas. As��, este trabajo introduce un proceso sistem��tico para construir un Diagnosticador de Fallos del sistema mencionado basado en RdR Esta novedosa herramienta es capaz de detectar fallos definitivos e intermitentes. El trabajo realizado es discutido desde un punto de vista te��rico y pr��ctico. El procedimiento comienza con la divisi��n del sistema en subsistemas para seguido integrar en una RdP diagnosticadora global que es capaz de monitorear el sistema completo y mostrar las variables cr��ticas al operador en orden a determinar la salud del UAV, para de esta manera prevenir accidentes. Un Sistema de Adquisici��n de Datos (DAQ) ha sido tambi��n dise��ado para recoger datos durante los vuelos y alimentar la RdP diagnosticadora. Vuelos reales realizados bajo condiciones normales y de fallo han sido requeridos para llevar a cabo la configuraci��n del diagnosticador y verificar su comportamiento. Vale la pena se��alar que un alto riesgo fue asumido en la generaci��n de fallos durante los vuelos, a pesar de eso esto permiti�� recoger datos b��sicos para desarrollar el diagn��stico de fallos, t��cnicas de aislamiento, protocolos de mantenimiento, modelos de comportamiento, etc. Finalmente, un resumen de la validaci��n de resultados obtenidos durante las pruebas de vuelo es tambi��n incluido. Un extensivo uso de esta herramienta mejorar�� los protocolos de mantenimiento para UAVs (especialmente helic��pteros) y permite establecer recomendaciones en regulaciones. El uso del diagnosticador usando redes de petri es considerado un novedoso enfoque. ABSTRACT Safety and reliability of industrial processes are the main concern of the engineers in charge of industrial plants. Thus, from an economic point of view, the main goal is to reduce the maintenance downtime cost and the losses caused by failures. Moreover, the safety of the operators, which affects to social and economic aspects, is the most relevant factor to consider in any system. Due to this, fault diagnosis has become a relevant focus of interest for worldwide researchers and engineers in the industry. The main works focused on failure detection are based on models of the processes. There are different techniques for modelling industrial processes such as state machines, decision trees and Petri Nets (PN). Thus, this Thesis is focused on modelling processes by using Interpreted Petri Nets. Petri Nets is a tool used in the graphic and mathematical modelling with ability to describe information of the systems in a concurrent, parallel, asynchronous, distributed and not deterministic or stochastic manner. PNs are also useful graphical visual communication tools as flow chart or block diagram. Additionally, the marks of the PN simulate the dynamics and concurrence of the systems. Finally, they are able to define specific state equations, algebraic equations and other models that represent the common behaviour of systems. Among the different types of PN (Interpreted, Coloured, etc.), this research work deals with the interpreted Petri Nets mainly due to features such as synchronization capabilities, timed places, apart from their capability for processing data. This Research begins with the process for designing and building the model and diagnoser to detect permanent faults, subsequently, the temporal dynamic was added for detecting intermittent faults. Two industrial processes, namely HVAC (Heating, Ventilation and Air Condition) and Liquids Packaging Process were used as testbed for implementing the Fault Diagnosis (FD) tool created. Finally, its diagnostic capability was enhanced in order to detect faults in hybrid systems. Finally, a small unmanned helicopter was chosen as example of system where safety is a challenge and fault detection techniques developed in this Thesis turn out to be a valuable tool since UAVs accidents involve high economic cost and are the main reason for setting restrictions to fly over populated areas. Thus, this work introduces a systematic process for building a Fault Diagnoser of the mentioned system based on Petri Nets. This novel tool is able to detect both intermittent and permanent faults. The work carried out is discussed from theoretical and practical point of view. The procedure begins with a division of the system into subsystems for further integration into a global PN diagnoser that is able to monitor the whole system and show critical variables to the operator in order to determine the UAV health, preventing accidents in this manner. A Data Acquisition System (DAQ) has been also designed for collecting data during the flights and feed PN Diagnoser. Real flights carried out under nominal and failure conditions have been required to perform the diagnoser setup and verify its performance. It is worth noting that a high risk was assumed in the generation of faults during the flights, nevertheless this allowed collecting basic data so as to develop fault diagnosis, isolations techniques, maintenance protocols, behaviour models, etc. Finally, a summary of the validation results obtained during real flight tests is also included. An extensive use of this tool will improve preventive maintenance protocols for UAVs (especially helicopters) and allow establishing recommendations in regulations. The use of the diagnoser by using Petri Nets is considered as novel approach.

Contribution to the improvement of communication services in nanosatellite constellations using delay and disruption tolerant networking based architectures

Esta tesis se desarrolla dentro del marco de las comunicaciones satelitales en el innovador campo de los peque��os sat��lites tambi��n llamados nanosat��lites o cubesats, llamados as�� por su forma cubica. Estos nanosat��lites se caracterizan por su bajo costo debido a que usan componentes comerciales llamados COTS (commercial off-the-shelf) y su peque��o tama��o como los Cubesats 1U (10cm*10 cm*10 cm) con masa aproximada a 1 kg. Este trabajo de tesis tiene como base una iniciativa propuesta por el autor de la tesis para poner en ��rbita el primer sat��lite peruano en mi pa��s llamado chasqui I, actualmente puesto en ��rbita desde la Estaci��n Espacial Internacional. La experiencia de este trabajo de investigaci��n me llevo a proponer una constelaci��n de peque��os sat��lites llamada Waposat para dar servicio de monitoreo de sensores de calidad de agua a nivel global, escenario que es usado en esta tesis. Es ente entorno y dadas las caracter��sticas limitadas de los peque��os sat��lites, tanto en potencia como en velocidad de datos, es que propongo investigar una nueva arquitectura de comunicaciones que permita resolver en forma ��ptima la problem��tica planteada por los nanosat��lites en ��rbita LEO debido a su car��cter disruptivo en sus comunicaciones poniendo ��nfasis en las capas de enlace y aplicaci��n. Esta tesis presenta y eval��a una nueva arquitectura de comunicaciones para proveer servicio a una red de sensores terrestres usando una soluci��n basada en DTN (Delay/Disruption Tolerant Networking) para comunicaciones espaciales. Adicionalmente, propongo un nuevo protocolo de acceso m��ltiple que usa una extensi��n del protocolo ALOHA no ranurado, el cual toma en cuenta la prioridad del trafico del Gateway (ALOHAGP) con un mecanismo de contienda adaptativo. Utiliza la realimentaci��n del sat��lite para implementar el control de la congesti��n y adapta din��micamente el rendimiento efectivo del canal de una manera ��ptima. Asumimos un modelo de poblaci��n de sensores finito y una condici��n de tr��fico saturado en el que cada sensor tiene siempre tramas que transmitir. El desempe��o de la red se evalu�� en t��rminos de rendimiento efectivo, retardo y la equidad del sistema. Adem��s, se ha definido una capa de convergencia DTN (ALOHAGP-CL) como un subconjunto del est��ndar TCP-CL (Transmission Control Protocol-Convergency Layer). Esta tesis muestra que ALOHAGP/CL soporta adecuadamente el escenario DTN propuesto, sobre todo cuando se utiliza la fragmentaci��n reactiva. Finalmente, esta tesis investiga una transferencia ��ptima de mensajes DTN (Bundles) utilizando estrategias de fragmentaci��n proactivas para dar servicio a una red de sensores terrestres utilizando un enlace de comunicaciones satelitales que utiliza el mecanismo de acceso m��ltiple con prioridad en el tr��fico de enlace descendente (ALOHAGP). El rendimiento efectivo ha sido optimizado mediante la adaptaci��n de los par��metros del protocolo como una funci��n del n��mero actual de los sensores activos recibidos desde el sat��lite. Tambi��n, actualmente no existe un m��todo para advertir o negociar el tama��o m��ximo de un ���bundle��� que puede ser aceptado por un agente DTN ���bundle��� en las comunicaciones por sat��lite tanto para el almacenamiento y la entrega, por lo que los ���bundles��� que son demasiado grandes son eliminados o demasiado peque��os son ineficientes. He caracterizado este tipo de escenario obteniendo una distribuci��n de probabilidad de la llegada de tramas al nanosat��lite as�� como una distribuci��n de probabilidad del tiempo de visibilidad del nanosat��lite, los cuales proveen una fragmentaci��n proactiva ��ptima de los DTN ���bundles���. He encontrado que el rendimiento efectivo (goodput) de la fragmentaci��n proactiva alcanza un valor ligeramente inferior al de la fragmentaci��n reactiva. Esta contribuci��n permite utilizar la fragmentaci��n activa de forma ��ptima con todas sus ventajas tales como permitir implantar el modelo de seguridad de DTN y la simplicidad al implementarlo en equipos con muchas limitaciones de CPU y memoria. La implementaci��n de estas contribuciones se han contemplado inicialmente como parte de la carga ��til del nanosat��lite QBito, que forma parte de la constelaci��n de 50 nanosat��lites que se est�� llevando a cabo dentro del proyecto QB50. ABSTRACT This thesis is developed within the framework of satellite communications in the innovative field of small satellites also known as nanosatellites (<10 kg) or CubeSats, so called from their cubic form. These nanosatellites are characterized by their low cost because they use commercial components called COTS (commercial off-the-shelf), and their small size and mass, such as 1U Cubesats (10cm * 10cm * 10cm) with approximately 1 kg mass. This thesis is based on a proposal made by the author of the thesis to put into orbit the first Peruvian satellite in his country called Chasqui I, which was successfully launched into orbit from the International Space Station in 2014. The experience of this research work led me to propose a constellation of small satellites named Waposat to provide water quality monitoring sensors worldwide, scenario that is used in this thesis. In this scenario and given the limited features of nanosatellites, both power and data rate, I propose to investigate a new communications architecture that allows solving in an optimal manner the problems of nanosatellites in orbit LEO due to the disruptive nature of their communications by putting emphasis on the link and application layers. This thesis presents and evaluates a new communications architecture to provide services to terrestrial sensor networks using a space Delay/Disruption Tolerant Networking (DTN) based solution. In addition, I propose a new multiple access mechanism protocol based on extended unslotted ALOHA that takes into account the priority of gateway traffic, which we call ALOHA multiple access with gateway priority (ALOHAGP) with an adaptive contention mechanism. It uses satellite feedback to implement the congestion control, and to dynamically adapt the channel effective throughput in an optimal way. We assume a finite sensor population model and a saturated traffic condition where every sensor always has frames to transmit. The performance was evaluated in terms of effective throughput, delay and system fairness. In addition, a DTN convergence layer (ALOHAGP-CL) has been defined as a subset of the standard TCP-CL (Transmission Control Protocol-Convergence Layer). This thesis reveals that ALOHAGP/CL adequately supports the proposed DTN scenario, mainly when reactive fragmentation is used. Finally, this thesis investigates an optimal DTN message (bundles) transfer using proactive fragmentation strategies to give service to a ground sensor network using a nanosatellite communications link which uses a multi-access mechanism with priority in downlink traffic (ALOHAGP). The effective throughput has been optimized by adapting the protocol parameters as a function of the current number of active sensors received from satellite. Also, there is currently no method for advertising or negotiating the maximum size of a bundle which can be accepted by a bundle agent in satellite communications for storage and delivery, so that bundles which are too large can be dropped or which are too small are inefficient. We have characterized this kind of scenario obtaining a probability distribution for frame arrivals to nanosatellite and visibility time distribution that provide an optimal proactive fragmentation of DTN bundles. We have found that the proactive effective throughput (goodput) reaches a value slightly lower than reactive fragmentation approach. This contribution allows to use the proactive fragmentation optimally with all its advantages such as the incorporation of the security model of DTN and simplicity in protocol implementation for computers with many CPU and memory limitations. The implementation of these contributions was initially contemplated as part of the payload of the nanosatellite QBito, which is part of the constellation of 50 nanosatellites envisaged under the QB50 project.