This paper presents the measurement and model updating of a pedestrian's center of mass trajectory. A mathematical model proposed by the authors is updated using the actual trajectory of a pedestrian. The mathematical model is based on the principle that a human's control capability tries to maintain balance with respect to the pedestrian's center of mass (CoM), independently of the surface type. In this research, the human is considered as a mass point concentrated at CoM. The parameters of the models are updated using experimental identification of the human walking trajectory on a rigid surface. The proposed measurement technique applies infrared emitter and a depth sensor, which enable skeletal tracking of the pedestrian walking on rigid or flexible structures. Experiments were performed using a mobile platform with the time-of-flight commercial camera Microsoft Kinect for Windows 2.0. The velocity of the mobile platform is set to maintain a one meter separation from the pedestrian in order to provide high resolution. The results allow identification of the human's trajectory and its relation to the walking surface's behavior.

Abstract: Different contract types means different incentives, burdens and relationships. The contract type responsibilities and price should be in accordance with the project needs and organization capacities, not knowing this could entail less project profitability and chances of success. It is necessary to understand the alternatives and how they behave, in order to develop the right strategies to avoid overruns and improve the project quality. The goal of this thesis is to develop a decision analysis model for contract type selection. This model will become a useful tool for contractor and client preferences in an easy and effective way. Decision analysis is a powerful tool that will help us to bring clarity of thought in this process; during this thesis it is described what is a project, its phases, activities and the components that understand it, in the same way it is presented the contract management life cycle. This model attempts to link and evaluate the contract types, differentiators, and the client and contractor preferences in order to quantify the costs and benefits of each type, which could be the best option. One priority of this thesis is to understand the synergetic relationship between contract type, contract management, project management and contract price, in order to take the best decision, increasing the probability to achieve a successful project execution. As application example, a contract type selection for the EPCI (Engineering, Procurement, Construction & Installation) of a topside for a semisubmersible platform is presented.Resumen: Diferentes tipos de contrato significa diferentes incentivos, cargas y relaciones. Las responsabilidades y el precio del tipo de contrato deben estar de acuerdo con las necesidades del proyecto y las capacidades de la organización, sin saber que esto podría implicar una menor rentabilidad del proyecto y posibilidades de éxito. Es necesario comprender las alternativas y la forma en que se comportan, a fin de desarrollar las estrategias correctas para evitar los excesos y mejorar la calidad del proyecto. El objetivo de esta tesis es desarrollar un modelo de análisis de decisión para la selección del tipo de contrato. Este modelo se convertirá en una herramienta útil para las preferencias de los contratistas y clientes de una manera fácil y efectiva. El análisis de decisiones es una herramienta poderosa que nos ayudará a tener claridad de pensamiento en este proceso; Durante esta tesis se describe qué es un proyecto, sus fases, actividades y los componentes que lo comprenden, de la misma manera que se presenta el ciclo de vida de gestión de contratos. Este modelo intenta vincular y evaluar los tipos de contrato, los diferenciadores y las preferencias del cliente y del contratista para cuantificar los costos y beneficios de cada tipo, lo que podría ser la mejor opción. Una de las prioridades de esta tesis es comprender la relación sinérgica entre el tipo de contrato, la gestión de contratos, la gestión de proyectos y el precio del contrato, para tomar la mejor decisión, aumentando la probabilidad de lograr una ejecución exitosa del proyecto. Como ejemplo de aplicación, se presenta una selección de tipo de contrato para el EPCI (Ingeniería, Aprovisionamiento, Construcción e Instalación) de un topside para una plataforma semisumergible.

Abstract: The Environmental Control System (ECS) allows the control of the environment within the cabin and flight deck for pilot and passenger comfort, and protects them from adverse weather conditions. This study presents a Matlab-Simulink® model developed to calculate the shaft power and ventilation required by the ECS during different flight conditions. The ECS model includes two blocks. The first block determines the requirements of the ECS by means of the analysis of thermal loads presented inside the helicopter. The second block computes the ECS air-conditioning pack of the helicopter (for cooling, heating and demisting). Two different ambient and flight conditions are simulated to find the power consumption of the air-conditioning pack once a comfortable cabin environment has been achieved. It is concluded that by using this model, the changes in the comfort level can be predicted in real time in order to intelligently reduce the ECS overall power consumption in a helicopter by choosing among five different ECS configurations the most appropriated, thus maintain the thermal comfort of the pilot and the passengers. Resumen: El Sistema de Control Ambiental (ECS por sus siglas en inglés) permite el control del ambiente dentro de la cabina y la consola de control del helicóptero, proporcionando confort y protección a los pilotos y pasajeros en condiciones climáticas adversas. Este estudio presenta un modelo en Matlab-Simulink® aplicable a diversas condiciones de vuelo para calcular la potencia mecánica y la ventilación requerida por el ECS. El modelo ECS incluye dos bloques. El primer bloque determina los requerimientos del ECS por medio del análisis de cargas térmicas presentadas en el interior del helicóptero. El segundo bloque computa el sistema de acondicionamiento de aire del ECS dentro de un helicoptero (para refrigeración, calefacción y desempañado). Dos condiciones diferentes de ambiente y de vuelo son simuladas para encontrar el consumo de potencia del sistema de acondicionamiento de aire una vez alcanzado un ambiente de cabina confortable. Se concluye que por medio de este modelo, los patrones de cambio próximos en el nivel de confort se pueden predecir en tiempo real con el fin de reducir de forma inteligente el consumo general de energía del ECS en un helicóptero al seleccionar entre 5 configuraciones la más apropiada, y asi mantener el confort térmico del piloto y los pasajeros.

As it has been proved in several researches carried out by different authors, riverine floods and the scour induced by these are one of the main causes of bridge collapse. More specifically, local scour causes a loss in the lateral resistance of bridge foundation, thus potentially increasing the seismic vulnerability of a bridge system. The present study assesses the combination of scour and earthquake effects for a bridge located in a road network crossing valleys in the Pyrenees Mountain range (France). The bridge spans over a river stream of trapezoidal cross-section, which is more able to capture actual physical behaviours than the rectangular section generally used for similar studies. The bridge consists in a continuous RC deck supported by two multi-column piers. Making use of the OpenSees software, a 3D finite-element model of the bridge is built and subjected to a suite of 312 ground motions (i.e., non-linear time history analyses). Fragility curves are developed for this multi-hazard case study, considering specific levels of damage that might be of interest, as well a comparison between fragility characteristics obtained in the absence and presence of scour. In order to fully study the potentially detrimental effects of scour on the dynamic behavior of the considered bridge, it is considered different scour combinations in the non-linear time-history analyses, such as: • Equal scour depth in all columns. • Same scour depth in the columns of the same pier. • Same scour depth in columns of different piers. • Scour depth concentrated in just one column of the bridge This study demonstrates the ability of a given numerical model to account for various hazard loadings and failure mechanisms, thus providing support to decision making regarding bridge management and monitoring.

Tesis presentada por Cristóbal Bernal para obtener el título de Ingeniero Civil en 1911. En ella presenta los resultados de investigación acerca del abasto de aguas para Bogotá. A lo largo del documento se discute acerca de la cantidad de agua necesaria para la ciudad, la calidad de ella, la forma en que se distribuye y la importancia del río San Francisco para cumplir este fin.

Miel I is a 188 m high RCC dam in Colombia, at elevation 454 m a.s.l. The RCC mix has a cement content of 85 to 160 kg/m3. To meet contractual schedule, the original design of an upstream face made of slip formed reinforced concrete was changed to a Carpi drained exposed composite Polyvinylchloride geomembrane (= PVC geocomposite) system, placed on a 0.4 m thick zone of RCC material enriched with cement grout and vibrated. Placement of the geocomposite system in horizontal stages allowed starting of dam impoundment while RCC placement was still ongoing at higher elevation. The geocomposite system was completed in 2002, before finishing of complementary concrete works. ISAGEN, the owner of the dam, constantly monitors the dam’s and geocomposite system’s performance. The average leakage of the dam registered since the first impoundment of the reservoir has been of 2 l/s for the geocomposite’s drainage system, and of 25 l/s from the abutments. Such levels are below the design parameters that defined the maximum acceptable leakage through the geocomposite in 9.7 l/s and the maximum acceptable leakage through the abutments in 30 l/s. The measured leakage has never surpassed the historical values (with stable lecture through 11 years), or overcome the maximum allowed drainage design values defined during the design stage. After 11 years of good performance and operation, in summer 2013 ISAGEN decided to have a comprehensive monitoring of the general conditions and the weathering behaviour of the waterproofing geocomposite at Miel I. The objectives of the investigation were: assessing the reason of small cuts that had been detected and repaired (in total 15 in 11 years on a 31,000 square meters surface), assessing the conditions of the PVC geocomposite, ascertaining at which extent its characteristics had changed over service, and evaluating if the weathering behaviour was in accordance with the expected durability. Investigation started with inspection at the upstream face and in the drainage galleries, followed by sampling of the exposed PVC geocomposites. Testing in an independent laboratory allowed comparing the physical and chemical properties of the aged geocomposite sample collected at the dam with the physical and chemical properties of the same geocomposite as manufactured. Evaluation of test results, based also on most recent research on geomembrane weathering mechanisms, completed the investigation. Results confirmed that the behaviour of the PVC geocomposite is extremely good and fully in line with expectations. The paper, after a brief outline of the geocomposite system installed at the dam, will describe all steps of the investigation, and detail the test results and the conclusions drawn.

In this work, an hybrid, self-configurable, multilayered and evolutionary subsumption architecture for cognitive agents is developed. Each layer of the multilayered architecture is modeled by one different Machine Learning System (MLS) based on bio-inspired techniques such as Extended Classifier Systems (XCS), Artificial Immune Systems (AIS), Neuro Connectionist Q-Learning (NQL) and Learning Classifier Systems (LCS) among others. In this research an evolutionary mechanism based on Gene Expression Programming (GEP) to self-configure the behaviour arbitration between layers is suggested. In addition, a co-evolutionary mechanism to evolve behaviours in an independent and parallel fashion is used. The proposed approach was tested in an animat environment using a multi-agent platform and it exhibited several learning capabilities and emergent properties for self-configuring internal agent’s architecture.

El presente estudio describe una propuesta alternativa para entender y detectar evidencias del fenómeno denominado “greenwashing” a nivel de la firma, tomando como referencia un incidente crítico ambiental de una empresa multinacional perteneciente al sector de la minería del carbón a gran escala en Colombia. Se soporta en la tipología de las transgresiones del “greenwashing”, identificando comportamientos explicativos contradictorios por parte de una compañía, incluyendo sus reportes de sostenibilidad. El estudio ilustra un planteamiento teo?rico soportado en un caso de estudio en donde se identifican elementos para reconocer señales de reportes difusos y en últimas, permita detectar el “greenwashing” corporativo.

Documento en el que se analizan y evalúan los rieles de hierro fabricados en La Pradera, los primeros que se hicieron en Colombia y en América del sur, en 1885. A lo largo del documento, que contiene gráficas, tablas y análisis de ingeniería, se realizan varias precisiones sobre la conveniencia de comprar y utilizar este tipo de rieles, y se pone a prueba la utilización de ellos en las vías del Ferrocarril La Sabana.

Las cuestiones fundamentales de electrónica analógica se tratan extensamente en este libro, que puede servir como manual en los primeros cursos de Ingeniería. Se abordan temas de señales, sistemas y componentes analógicos básicos, semiconductores, diodos y transistores, amplificadores de pequeña señal con BJT y FET, amplificadores diferenciales y operacionales, así como fuentes de alimentación y reguladores.