The main challenge of this Thesis is to reliably preserve quality of service (QoS) contracts in component-based software systems under changing conditions of system execution. In response to this challenge, the presented contribution is twofold. The first is a model for component-based software applications, QoS contracts and reconfiguration rules as typed attributed graphs, and the definition of QoS-contracts semantics as state machines in which transitions are performed as software reconfigurations. Thus, we effectively use (formal) models at runtime to reliably reconfigure software applications for preserving its QoS contracts. More specifically, we show the feasibility of exploiting design patterns at runtime in reconfiguration loops to fulfill expected QoS levels associated to specific context conditions. We realize this formal model through a component-based architecture and implementation that can be used as an additional layer of SCA middleware stacks to preserve the QoS contracts of executed applications.  The second contribution is the characterization of adaptation properties to evaluate self-adaptive software systems in a standardized and comparable way. By its own nature, the adaptation mechanisms of self-adaptive software systems are essentially feedback loops as defined in control theory. Thus, it results reasonable to evaluate them using the standard properties used to evaluate feedback loops, re-interpreting these properties for the software domain. We define the relibility of our formal model realization in terms of a subset of the characterized adaptation properties, and we show that these properties are guaranteed in this realization.

La regularidad de intervalos entre buses ha demostrado mejorar el nivel de servicio de sistemas de transporte público, reduciendo tiempos de espera de pasajeros, balanceando la carga de los buses y logrando ahorros en costos operacionales. Este trabajo evalúa el modelo de optimización desarrollado por Delgado et al. (2012), que controla los intervalos entre buses, a través de su implementación en EMBARQ BRT Simulator, usando datos reales y teniendo en cuenta consideraciones prácticas de implementación. Se adaptó EMBARQ BRT Silmulator para incluir las estrategias de control en la simulación y permitir su interacción con el modelo de optimización que fue modificado para permitir la solución de problemas de gran tamaño. Para estudiar los beneficios de las estrategias de control se usan datos reales de la única línea que opera en el corredor BRT Insurgentes de Ciudad de México D.F.Se definen y evalúan escenarios donde se establecen los beneficios de implementar diferentes esquemas de control en el corredor. Los parámetros estudiados incluyen: (i) intervalo de tiempo entre optimizaciones; (ii) número de paraderos incluidos en la optimización; y (iii) combinación de acciones de control como retención (holding), delimitación de pasajeros a abordar el bus (boarding limits) y la posibilidad de no permitir subidas en determinadas paradas. Para el caso de estudio, la estrategia de sólo holding, optimizando cada 2 minutos y considerando 12 de los 72 paraderos, redujo en 21% los tiempos de espera total percibidos, la variabilidad en 39% y mostró ahorros para el operador del 5% de la flota. Las estrategias que consideran limitaciones prácticas, mostraron beneficios similares a los casos sin ellas, demostrando su factibilidad de implementación en casos reales. Finalmente, se recomienda implementar el modelo en un corredor real, donde se podría usar EMBARQ BRT Simulator para la evaluación de estrategias de control.

Desde una perspectiva psicosocial, el concepto sobre el cual se han soportado los estudios sobre burnout, en cuerpos de policía, corresponde a la definición establecida por Maslach, entendiendo el síndrome como una respuesta al estrés laboral crónico que se caracteriza porque el individuo desarrolla una idea de fracaso profesional (en especial en relación a las personas hacia las que trabaja), la vivencia de encontrarse emocionalmente agotado y actitudes negativas hacia las personas con las que trabaja (Maslach y Jackson, 1981,1986). Tomado de Gil-Monte y Peiró (1999). La mayor incidencia del síndrome de quemarse por el trabajo se da en profesionales de servicios que prestan una función asistencial o social, generando deterioro en su calidad de vida laboral y con repercusiones sobre la sociedad en general, especialmente en profesionales sanitarios, profesionales de la educación, trabajadores sociales, funcionarios de prisiones o policías (Gil-Monte, Peiró, 1997), como resultado de algunos factores en el trabajo: alto número de usuarios, prevalencia de respuestas negativas por parte de los usuarios y falta de recursos (Maslach, Schaufeli & Leiter, 2001).  Los resultados de las investigaciones adelantadas hasta la fecha, no permiten generalizar características particulares de los componentes de burnout en cuerpos de policía, lo cual ha llevado a que en el desarrollo del presente trabajo se realice un análisis causa-efecto, de los factores situacionales e individuales que han sido estudiados, con el fin de dar elementos de juicio que permitan entender el desarrollo del síndrome en este colectivo. Finalmente, se presentan las conclusiones a las que se ha podido llegar como resultado del aprendizaje en la profundización de este, junto con una propuesta de una agenda futura sobre el estudio del burnout, tanto a nivel teórico como aplicado, con el fin de servir de referente en las organizaciones policiales, que incentive el desarrollo de políticas y programas en la gestión de los recursos humanos dirigidos a ofrecer a los trabajadores recursos efectivos buscando mejorar las condiciones de bienestar individual, grupal y organizacional en este grupo poblacional.

The dissertation develops an analysis of how speed (as a quotient of space and time) has been described as a positive attribute and an adequate solution to industrial development, cities' efficiency and, in general, citizens' well being, while time?space compression as an underlying process has been widely studied but rarely acknowledged in policy. It analyses the evolution of the discourse on speed from before Bogotá’s BRT system “TransMilenio” (in 1996) and until recently (in 2006) and how it may have influenced such discourse. It questions the usefulness of speed and some transport interventions in Bogotá, and how other more structural measures may be taken to solve a city’s ills. The dissertation provides a conceptual framework on time, cities and time?space compression and speed, followed by a description of Bogotá and TransMilenio and results of the study. It ends with a discussion on the role of speed in Bogotá, the evolution of transport planning, and time?space compression and how it relates to the case in question. 

New generation wireless communication systems should support the increasing demand for efficient utilization of the electromagnetic spectrum. The Cognitive Radio (CR) paradigm is envisioned as a new technique to realize this goal. Nowadays, Software Defined Radios (SDRs) are the foundations on which the CR will be achieved. In this thesis we implemented an SDR network testbed based on a GNU radio platform. The test network was used to evaluate the actual performance of two methods that attempt to contribute as constituents of a Radio Environment Map (REM). REMs are a new approach to provide situation awareness for CRs. The first technique under analysis was a colouring-based frequency allocation mechanism that optimizes the assignment of frequency channels in the 2.4 GHz band. Its effectiveness was demonstrated using several performance tests in different scenarios and conditions. This study also explores the viability of using our SDR testbed to execute real-time power measurements to estimate the dynamics of indoor radio propagation. This is a preliminary step to obtain complete radio environment awareness, and thus contribute towards realizing the REM and CR approaches. 

En el campo de estudio de los Agentes Autónomos Inteligentes, uno de los retos más complejos de lograr es la simulación de los procesos cognitivos. Generalmente, la meta de integrar diversas micro-teorías en un solo modelo cognitivo que sea capaz de procesar ingentes cantidades de variables, las cuales cambian continuamente con una complejidad incremental, resulta ser una tarea intrincada cuyos frutos no siempre suelen reflejar las expectativas iniciales de sus diseñadores. En el área de la Cognición Artificial es posible distinguir tres grandes aproximaciones: la Cognitivista, basada en sistemas de representación simbólica y mecanismos de aprendizaje explícito; la Emergente, fundamentada en sistemas de representación sub-simbólica y procesos cognitivos de naturaleza implícita; y la Híbrida, que busca integrar lo mejor de cada aproximación. Esta última, a pesar de ser un enfoque conciliador que pretende compensar las debilidades y potenciar las fortalezas de cada aproximación, es un área de investigación muy reciente cuyos resultados son aún incipientes. En la presente tesis, se propone un modelo cognitivo híbrido y original, denominado Metáfora, cuyas aportaciones principales son: (1) la integración de teorías multi-disciplinares -- psicocognitivas, neurológicas, biológicas, de inteligencia artificial, etc. -- sobre la cognición; (2) un diseño arquitectónico basado en bloques de construcción cibernéticos, que adapta lo mejor de los modelos cognitivos más representativos -- diseño por capas, modular, multi-componente, descentralizado, y distribuido; (3) la fusión de los principios propuestos tanto por la aproximación cognitivista como por la aproximación emergente, y la definición de los mecanismos de integración y sincronización necesarios para comunicar estos dos niveles; y (4) un diseño innovador que articula tres niveles de auto-organización inspirados en principios de la biología evolutiva y del desarrollo: la epigénesis, la ontogénesis, y la filogénesis, a partir de los cuales emergen las diversas estructuras cognitivas de la arquitectura. En el nivel epigenético se define una capa cognitiva controlada por dos clases de máquinas autopoiéticas (i.e., los Sistemas Inmunes Artificiales y las Redes Neuronales Artificiales), cuya responsabilidad es crear las estructuras cognitivas de bajo nivel y dotar a la arquitectura con un grado significativo de plasticidad. En el nivel ontogenético, por un lado, se precisa un mecanismo atencional adaptativo el cual es capaz de orquestar los diversos comportamientos y procesos conscientes y subconscientes del agente, empleando para ello un modelo evolutivo de dispersión de energía de activación y, por otro, se define un mecanismo que evoluciona las estructuras cognitivas de orden superior. Por último, en el nivel filogenético, se propone un mecanismo basado en la ingeniería memética, encargado de co-evolucionar y trasmitir las estructuras cognitivas a través de la sociedad de agentes.

The transport for disabled people at the Rône-Alpes Region constitutes a complex and multi-dimensional system. Numerous actors interact constantly, most of them with conflicting objectives. In this sector, the economic efficiency cannot determine the system performance. As a matter of fact, aspects such us quality of service and human side effects, say pathological or emotional incompatibilities, might play a critical role. In this master thesis we will examine the daily transport of children with disabilities at Lyon urban center in two main phases: 1) a qualitative analysis of the stakeholders, their motivations and interactions 2) a quantitative study to determine the benefit of optimizing the transport system considering passengers constraints with heterogeneous and reconfigurable vehicles. The proposed optimization problem is not yet covered in the scientific literature.

The number of distributed resources into electrical network systems is increasing and it is challenging the way these systems are designed and operated. For traditional power systems, transmission and distribution networks play a passive role in voltage control. When distributed generation is presented these levels of the electrical network can play an important role in voltage regulation. The mini CHP technology is an interesting option for this active role. In this study, a voltage control strategy using mini CHP units is proposed. For this purpose a dynamic model of a mini CHP system using experimental data is developed and is represented in Matlab/Simulink for simulation. An electrical network for performing these studies is built in DIgSILENT PowerFactory and the mini CHP system model is integrated into the electrical network. The proposed voltage control operation mode is compared with a heat lead operation mode for determining advantages and disadvantages of both operations. The voltage control operation is an interesting option for regulating voltage in the distribution network when distributed resources are introduced. Further studies and developments are required to find a compromise between voltage regulation and thermal demand matching.

Recent technological developments in mechanical investigation techniques and nondestructive monitoring of masonry buildings provide today an amount of information, unthinkable up until yesterday. Likewise the techniques of automated laser survey allow a rapid and precise definition of the geometry of a building, with a level of detail never previously reached. On the other hand, the applications to the modeling of complex masonry historical structures are not as widespread, and constitute an interesting subject of research. Despite the fact that numerical modeling techniques based on the finite element method have progressed considerably, and the computing power available is constantly growing. The difficulties that are encountered are manifold, and reside especially on the absence of well consolidated procedures for the definition of the model and for the management of uncertainties. The Asinelli Tower in Bologna is taken as a case study to define a general methodology for the analysis of historical masonry towers. Using the finite element code DIANA (TNO Diana, Netherlands) the difficulties that are typically encountered in building models of increasing complexity are addressed, proposing a general procedure. The study of the tower, although not directed to the formulation of an explicit judgment on the structural stability, has led to the formulation of an anisotropic cracked masonry model, capable of representing the dynamic behavior of the tower with greater efficiency compared to what is available in the scientific literature.

Socio economic reintegration of former combatants is one the most complicated stages in the aftermath of armed struggles and there is never a straightforward answer to its implementation. Although there has been theoretical and practical progress in these regards, ex-combatants often must face formal an informal constraints before regaining their citizenship. In these contexts, institutional interventions are crucial to facilitate the transition of this population into civilian life. This research analyses the role of the institutional framework and its impact in the proper economic reintegration of former politically motivated combatants in Colombia and Northern Ireland since 2000. Through a rigorous review of international examples, previous experiences in reintegration programmes, public policies and the examination of extensive literature, it was possible to identify punitive legislation, limited employment opportunities, discrimination, lack of skills and informal economies as main factors affecting the reintegration process. This overview was confronted with data collected through six semi-structured interviews with key actors in Colombia and Northern Ireland who have been deeply involved in conflict resolution matters. As a result of this triangulation, this exploration compares and concludes that the Colombian institutional framework is more advanced in terms of socio-economic reintegration of ex- combatants in comparison to the Irish case in which ex-prisoners’ role after the Good Friday/Belfast Agreement is not clear yet. In addition, this research identifies that former politically motivated combatants are still experiencing similar problems such as discrimination, exclusion and high levels of deprivation that official interventions have not been capable of addressing in both countries. Finally, two recommendations are stated in order to strengthen these programmes from a people-centred perspective and a sensitive approach that takes into account specificities of ex-combatants in terms of employment, self-employment and training.