Based on the problem of the number of accident victims in contrast, concepts that were identified in cases of successful mobility solutions in the world are presented and have enabled pedestrians to have greater safety in the cities where they are located. They have implemented smart pedestrian crossings. In this document are developed concepts such as: Smart Cities, Digital Mobility, Digital Ecosystem, Digital Citizenship, Digital Life, Digital Governance, Intelligent Transport Systems (ITS) to associate the proposed solution with people and their current digital environment. Identifying what is an intelligent pedestrian crossing, detailing its components and the technology available to each of them. Finally, it is proposed to focus on Bogota with a digital city approach to develop citizens-oriented traffic, improving mobility through public transport systems with connectivity, reducing the use of alternative means of transport, considering pedestrians, cyclists and drivers. The former starting with an alternative of sustainable solution to the problem of mobility: Intelligent Transportation Systems, which bring together technological, digital and communications advances, counting on the digital transformation of the components of pedestrian crossings.

The low-level jet over the Orinoco River basin is characterized using finer horizontal, vertical, and temporal resolution than possible in previous studies via dynamical downscaling. The investigation relies on a 5-month-long simulation (November 2013–March 2014) performed with the Weather Research and Forecasting model, with initial and boundary conditions provided by the Global Forecast System analysis. Dynamical downscaling is demonstrated to be an effective method to better resolve the horizontal and vertical characteristics of the Orinoco low-level jet, not only improving its diurnal and austral-summer evolution, the identification and location of low-level jet streaks inside the stream tube, but also in determining the mechanisms leading to its formation. The Orinoco low-level jet (OLLJ) is found to be a single stream tube over Colombia and Venezuela with wind speeds greater than 8 m s-1, and four distinctive cores varying in height under the influence of sloping terrain. The OLLJ has its maximum monthly mean wind speed (13 m s-1) and largest spatial extent (2100 km × 400 km) in January. The maxima mean wind peeds (13–17 m s-1) in the diurnal cycle occur in the early morning above the nocturnal inversion; wind speeds are a minimum (8–9 m s-1) in the late afternoon when a deep, approximately unstratified boundary layer is present. The momentum balance analysis performed in a streamwise- and crosswise-rotated coordinate system reveal that the OLLJ is the result of four phenomena acting together to accelerate the wind: a sea-breeze penetration over the Orinoco River delta and Unare River depression, katabatic flow down the Coastal Cordillera, three expansion fans from point wakes in topography, and diurnal variation of turbulent diffusivity. La corriente en chorro de bajo nivel sobre la cuenca del río Orinoco es caracterizada, a través de una reducción dinámica de escala, con mayor resolución horizontal, vertical, y temporal que la obtenida en investigaciones previas. El estudio está basado en una simulación de 5 meses (noviembre 2013-marzo 2014) realizada con el modelo de investigación meteorológica y pronóstico WRF-ARW, y con condiciones iniciales y de frontera provenientes de los análisis del sistema de pronóstico global GFS-Analysis. La reducción dinámica de escala demuestra ser un método eficaz para resolver de una mejor manera las características horizontales y verticales de la corriente en chorro de bajo nivel del Orinoco, no sólo mejorando la descripción de su evolución diurna y estacional (verano austral), la identificación y localización de los núcleos de velocidad máxima del viento, sino también en la determinación de los mecanismos que conducen a su formación. Se encontró que la corriente en chorro de bajo nivel del Orinoco (OLLJ) es un tubo de corriente sobre Colombia y Venezuela con velocidades de viento mayores a 8 m s -1 , que tiene cuatro núcleos característicos que varían en altura debido a la influencia de la topografía circundante. En enero, el OLLJ presenta su máxima velocidad media mensual del viento (13 m s -1 ) y mayor extensión espacial (2100 km x 400 km). La máxima velocidad media del viento (13 – 17 m s -1 ) en el ciclo diurno ocurre temprano en la mañana por encima de la inversión nocturna, mientras que la velocidad mínima (8 – 9 m s -1 ) ocurre en la tarde cuando la capa de límite es profunda y aproximadamente neutra (i.e., sin estratificación). El análisis de balance de momento realizado en un sistema de coordenadas orientado en el sentido del flujo (coordenadas naturales), revela que el OLLJ es el resultado de cuatro fenómenos que actúan juntos para acelerar el viento: una penetración de la brisa de mar sobre el delta del río Orinoco y la depresión del río Unare, vientos catabáticos descendientes de la cordillera de la Costa, tres ventiladores de expansión que se desprenden de puntos topográficos, y la variación diurna en la difusión de la turbulencia.

This dissertation offers a comprehensive interpretation of the political philosophies of Thomas Hobbes, Jean-Jacques Rousseau, and Immanuel Kant, and highlights some common principles of their theories of state legitimacy. While the respective parts of the dissertation can be read as freestanding monographs, they jointly illustrate the appeal of a specific understanding of the problem of political legitimacy. Hobbes, Rousseau, and Kant took legitimacy to be about the right to perform as a state—the right, that is, to be the sole entity authorized to act and speak in the people’s name. Notably, they believed that this right was conceptually independent from the quality of the state’s performance. For these early modern thinkers, legitimacy is a normative property that cannot be ascribed to states merely as a function of the degree to which they exercise their coercive power in accordance with principles of social justice. The distinction between legitimacy and justice as independent dimensions of political evaluation is exegetically illuminating in the context of Hobbes, Rousseau, and Kant. Furthermore, it is an important philosophical and practical insight in its own right. In this regard, Kant’s political philosophy stands out as a model for constructing a theory of legitimacy that captures the fact that a peaceful, orderly, and law-bound social world—a Rechtsstaat—is an enormous achievement worth protecting despite the injustices with which it can often coexist. Esta disertación plantea una interpretación exhaustiva de la filosofía política de Thomas Hobbes, Jean-Jacques Rousseau y Emmanuel Kant, y destaca algunos principios comunes sus respectivas teorías de la legitimidad del estado. Si bien cada parte de la disertación puede verse como una monografía independiente sobre el autor de que se trate, juntas ilustran los atractivos conceptuales de una manera puntual de entender el problema de la legitimidad. Hobbes, Rousseau y Kant concebían el problema de la legitimidad como concerniente al derecho de desempeñarse como estado, es decir, el derecho de ser la única entidad autorizada para obrar y hablar en nombre del conjunto de los ciudadanos. Es más, los tres entendían tal derecho como conceptualmente independiente de la calidad del desempeño del estado. Para estos pensadores de la modernidad temprana, la legitimidad es una propiedad normativa que no puede atribuírsele a un estado solamente en función de qué tanto utiliza este su poder coercitivo en pro de los principios de justicia social. La distinción conceptual entre legitimidad y justicia como dimensiones independientes de evaluación de las instituciones políticas tiene importantes implicaciones para la interpretación de Hobbes, Rousseau y Kant. Más allá de eso, es un postulado de gran importancia filosófica y práctica. Visto desde esa perspectiva, el pensamiento político de Kant sobresale como modelo para la construcción de una teoría de la legitimidad del estado capaz de dar la importancia debida al hecho de que un universo social pacífico, ordenado y regido por la ley—un Rechstaat, como él lo llamara—es un logro extraordinario que merece ser cuidado a pesar de las injusticias con las que frecuentemente coexiste.

Abstract: Within this thesis, some of the major rigorous thermodynamic models available in the commercial process simulation tool Aspen Plus are tested for their suitability in the description of a process for the hydroformylation of dodecene in a DMF/decane thermomorphic solvent system, and applied within the rigorous process simulation of this system. The activity coefficient model NRTL is applied together with the rigorous Henry’s law, and its performance on LLE and GLE description is evaluated, respectively. In addition, the flexible equation of state model RKS, using modified Huron-Vidal mixing rules based on the activity coefficient method NRTL, is evaluated as well. Both methods are able to describe LLE and GLE within the range of process operation. The use of a purely predictive model PSRK or predictive methods to calculate required NRTL parameters is also evaluated. It is evidenced in this work that original UNIFAC method fails in the prediction of the LLE Tridecanal-DMF-Decane, so that only modified UNIFAC methods should be considered for a predictive calculation of this phase equilibria. The influence of the thermodynamic model selection on the simulation results is quantified and compared with available experimental data from a Miniplant with full recycle between reactor and decanter. This influence is found on the calculation of liquid molar volumes, which considerably affects simulation results. Resumen: En esta tesis, algunos de los principales modelos termodinámicos rigurosos disponibles en la herramienta comercial de simulación de procesos Aspen Plus son evaluados en su capacidad para describir un proceso de hidroformilación de dodeceno en un sistema termomórfico de solventes DMF/decano aplicado dentro de la simulación rigurosa de proceso de este sistema. El modelo de coeficiente de actividad NRTL se aplica junto con la ley rigurosa de Henry, y su desempeño en la descripción de los equilibrios líquido-líquido y gas-líquido es evaluada. Adicionalmente, también se evalúa el modelo de ecuación de estado RKS, usando las reglas de mezcla modificadas Huron-Vidal basadas en el método de coeficiente de actividad NRTL. Ambos métodos son capaces de describir los equilibrios líquido-líquido y gas-líquido dentro del rango de operación del proceso. El uso de un modelo puramente predictivo como el PRSK o métodos predictivos para calcular los parámetros NRTL requeridos también se evalúa. En este trabajo se evidencia que los métodos de UNIFAC originales fallan en la predicción del equilibrio líquido-líquido del sistema Tridecanal-DMF-Decano, de tal manera que sólo los métodos UNIFAC modificados deben ser considerados para el cálculo predictivo de este equilibrio de fases. La influencia de la selección del modelo termodinámico en los resultados de simulación de proceso es cuantificada y comparada con los datos experimentales disponibles de una Miniplanta con reciclo total entre el reactor y el decantador. Se encontró que el cálculo de los volúmenes molares de líquido afectan considerablemente los resultados de la simulación.

Abstract: In many developing countries motorcycles are used not only for personal travel (commuting, leisure, etc.) but also to deliver documents and small commodities (e.g., food) or to provide taxi services. Incomes of these commercial motorcyclists are generally based on the number of services they are able to provide within a given amount of time. Some have suggested that this incentive might induce commercial motorcyclists to engage in risky behaviors – that is they might be more likely to drive fast and break traffic laws in order to maximize income. To empirically test for differences between commercial and non-commercial motorcyclists, I estimated a logistic regression model using data from a survey conducted in Bogota and Barranquilla, Colombia. My results support the hypothesis that motorcycles used for commercial activities and whose income is generally based on the number of services they are able to provide are at a higher risk of being involved in a crash. The probability of being involved in a crash is higher when using motorcycles for taxi services than when using motorcycles for non-commercial purposes or for commercial activities other than courier or taxi services (after controlling for exposure, demographic characterizes, vehicle features, and other possible explanatory variables, though this finding may be affected by a possible reporting bias by those providing (illegal) taxi services). By contrast, motorcyclists who provide courier services have neither a higher nor lower probability of being involved in a crash compared to those riding motorcycles for non-commercial purposes or for commercial activities other than courier or taxi services. Other variables associated with crash occurrence include age, owning the motorcycle, and riding in Bogota. While I see evidence that the financial incentives of being paid per job motivate risky driving behaviors among commercial motorcyclists, better data and further research are needed to fully understand the causes of differential crash risks among types of motorcyclists. Resumen: En muchos países en desarrollo, las motocicletas se usan no solo para viajes personales (viajes diarios, tiempo libre, etc.) sino también como herramienta de trabajo para realizar reparto de documentos y paquetes pequeños (por ejemplo, alimentos) o para proporcionar servicios de transporte de pasajeros. Los ingresos de estos motociclistas generalmente se basan en la cantidad de servicios que pueden proporcionar dentro de un período de tiempo determinado. Algunos han sugerido que este incentivo puede inducir a los motociclistas comerciales a involucrarse en conductas de riesgo, es decir, que es más probable que conduzcan más rápido y que no cumplan las leyes de tránsito para maximizar sus ingresos. Para evaluar empíricamente las diferencias entre los motociclistas comerciales y no comerciales, estimé un modelo de regresión logística utilizando los datos de una encuesta realizada en Bogotá y Barranquilla, Colombia. Mis resultados respaldan la hipótesis de que las motocicletas utilizadas para actividades comerciales y cuyos ingresos generalmente se basan en la cantidad de servicios que pueden proporcionar corren un mayor riesgo de verse involucrados en un choque. La probabilidad de verse involucrado en un choque es mayor cuando se usan motocicletas para servicios de taxi que cuando se usan para fines no comerciales o para actividades comerciales que no sean de mensajería o taxi (después de controlar por exposición, características demográficas, características del vehículo y otros posibles variables explicativas, aunque este hallazgo puede verse afectado por un posible sesgo de información por parte de quienes prestan servicios de taxi (ilegales). Por el contrario, los motociclistas que prestan servicios de mensajería no tienen una probabilidad mayor o menor de verse involucrados en un choque en comparación con aquellos que conducen motocicletas con fines no comerciales o para actividades comerciales que no sean los servicios de mensajería o taxi. Otras variables asociadas con la ocurrencia del choque incluyen la edad, poseer la motocicleta y andar en Bogotá. Aunque la evidencia sugiere que los incentivos económicos derivados de la actividad motivan conductas de conducción arriesgadas entre los motociclistas comerciales, es necesario investigar en mayor profundidad las causas de los riesgos de choque diferencial entre los tipos de motociclistas.

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.

Wind power is one of the key players in the European Union target of 20% share of energy from renewable sources in 2020 to reduce greenhouse gas emissions and dependence on energy supply. In order to accomplish such target, some European countries are placing the wind farms further from the coast to exploit the higher wind speeds at open sea. However the traditional transmission system for offshore wind farms based on High Voltage Alternate Current (HVAC) is not appropriate for long distances. Hence, this research work was carried out to examine and determine the most suitable transmission system for offshore wind farms in terms of technical, environmental and economic costs. The methodological approach employed in the investigations was arranged in two parts. First, a quantitative and qualitative method of literature review involving critical examination of documented information and experiences of the two commercially available transmission systems: HVAC and HVDC (High Voltage Direct Current); second, a quantitative method that investigates and analyzes an adequate transmission system for a propose an offshore wind cluster in terms of economic and environmental costs. From the analysis, HVDC based on Voltage Source Converters (VSC) exhibited technical superiority over HVAC for long distance submarine transmission, control of active and reactive power, grid support and connection of asynchronous grids. Furthermore, in the proposed offshore wind farm cluster of 1 GW of installed capacity located at 150 km from the point of connection, after a distance of 90 km HVDC becomes more economic due to reduced system losses, and after a distance of 125 km HVDC presents lower environmental impacts associated with the raw materials used in the transmission system. At such point, particular to each transmission project, VSC-HVDC surpasses HVAC in technical, environmental and economic terms.

Colombia presents an elevated vulnerability to climate change with the highest recurrence of extreme weather events and increasing emergencies on the continent (Ideam et al, 2010). The Colombian government has been developing The Colombian Strategy for Low Carbon Development, seeking to mitigate climate change impacts in the country (Ideam et al, 2010); however, it is currently at designing stage and no actions have been implemented so far. The United Kingdom (UK) has been a global pioneer in low carbon development, with applied strategies at national and local scale that have involved the wider community. In addition, other non-governmental initiatives have promoted low carbon development from a community perspective, looking for a more localised and resilient community, through local projects implementation on food, energy production and Housing (Hopkins, 2008). As a result, UK case studies have provided a solid panorama since community initiatives have shown significant key learnings (Hopkins, 2011) providing an opportunity for achieving a climate-resilient growth in Colombia. Consequently, the present research aimed study to what extent, United Kingdom low carbon communities case studies, with particular reference in Transition Leicester, can be applied within the Colombian climate change scheme. The low carbon measures implemented and different stakeholders involve in UK low carbon communities were identified in order to obtain an insight scheme in Colombia, where opportunities and constrictions of its applicability were subsequently analysed, since socioeconomic conditions in Colombia vary considerably from the UK scheme, with a constant social conflict scenarios, large regional inequalities and an increasingly affected biodiversity (Côté et al, 2010; Ideam et al, 2010). Given the masters connotation of the study, further research is recommended.

This paper develops a common agency problem using a two stages menu auction game to show how pressure groups can aid in deciding how much public good should be provided. By sorting people into different pressure groups that represent the individuals’ preferences for the public good, the interaction among the pressure groups is an important element that could improve the provision of public goods. This paper sketches a very simple mechanism to provide a general contribution to finance a public good. In this model, the presence of pressure groups improves the undersupply of public goods typical in voluntary contribution models, while avoiding the distortionary effects of non-lump-sum transfers of the involuntary contributions models.

The purpose of this essay is to explain why it is not only reasonable but also necessary for companies that aim to survive in the long term, to adapt to the shifts that have happened in the market by embedding a system thinking and becoming sustainable businesses, through the adoption of sustainable business strategies that deliver benefits for the Triple Bottom Line. This paper first describes the current situation of the Earth, it will also describe the existing criticism towards businesses and the raising expectations for business acting as a source of long-term solutions and change. Subsequently, it exposes the main reasons why it has been so difficult for businesses to see a business case for sustainability. Finally, this essay demonstrates that to survive in the long term it is of vital importance for companies to embed sustainable business strategies and sustainable business models that deliver benefits for the Triple Bottom Line.