This study presents an analysis on data from multiple power meters across Monash University in Australia. Special emphasis is made on the methodology to fill the missing values and fix the wrong data. Different techniques were used to analyse the data: visual analytics, k-means clustering and principal component analysis. Este estudio presenta un analisis de datos provenientes de multiples medidores de consumo eletrico en la Universidad Monash en Australia. Se hace especial enfasis en la metodologia para llenar los datos faltantes y depurar los existentes. Ademas de “visual analytics” se usaron diversas tecnicas, entre ellas: “principal component analysis” y “k-means clustering”.

The flood event is a problem that may affect drastically any settlement and can bring dramatic consequences, especially when it is not considered as one of the urbanization dynamics. It is important to reduce floods with measures that can be as simple as self‐preparedness, as well as an integrated long‐term plan. Hence, it is essential to avoid loss of lives taking preventive measures and building a resilience perspective into the population. The present document describes the main concepts that should be taken into consideration to understand the flood risk. Consequently, analyses the current flood risk in Bogota, Colombia and seeks to determine the zones where vulnerable settlements overlay flood hazard areas. Finally, it is examined how flood risk management can be targeted to reduce the risk level and how can the design solutions help to prevent and manage the flood problem within the city. Resumen La inundación es un problema que puede afectar drásticamente cualquier asentamiento y puede traer severas consecuencias, especialmente cuando no se considera como una de las dinámicas de la urbanización. Es importante reducir las inundaciones con medidas que pueden ser tan simples como el autoaprendizaje, así como un plan integrado a largo plazo. Por lo tanto, es esencial evitar la pérdida de vidas tomando medidas preventivas y construyendo una perspectiva de resiliencia en la población. El presente documento describe los conceptos principales que deben tomarse en consideración para comprender el riesgo de inundación. En consecuencia, analiza el riesgo de inundación actual en Bogotá, Colombia y busca determinar las zonas donde los asentamientos vulnerables se sobreponen a las áreas en peligro de inundación. Finalmente, se examina cómo la gestión del riesgo de inundación puede orientarse para reducir sus niveles y cómo las soluciones de diseño pueden ayudar a prevenir y gestionar el problema de inundación dentro de la ciudad.

The oil and gas industry has long recognized the inadequacy of existing theories to predict the behavior and outcome of some hydraulic fracturing treatments. Data sets compiled over the last two decades are incompatible with the conventional picture of a single planar hydraulic fracture. These data sets include field studies, laboratory studies and theoretical models. Several field and laboratory observations show very complex fracture paths, multisegmented fractures, branching, asymmetry and the presence of multiple fractures. The purpose of this study is to investigate the pressure behavior of systems containing near wellbore and far field multiple vertical fractures. This objective is achieved by using two analytical models. These newly developed models are used to explore pressure behavior and to generate type curves using the pressure derivative concept. The first new analytical model considers a composite reservoir with the inner zone containing an arbitrary number of dendritic multiple hydraulic fractures and the outer zone showing natural fractures. Transient pressure, derivative and flow regimes of the fractured system are investigated using this model. This study also uses a numerical model to calibrate and validate the analytical model. Pressure transient behavior of multiple fractures is modeled using a full field model (FFM) with a detailed Cartesian local grid refinement (LGR) around the fractures. The model was calibrated and validated using the case of two wing fractures at 180o. Simulations of the two types of multiple fractures, dendritic and parallel, validate some results of the analytical solutions. The TDS technique is also used to analyze the linear and pseudo-radial flow regimes in order to find fracture length, angle between fractures, fracture conductivity and several conventional reservoir parameters, e.g. permeability, wellbore storage and skin.  Multiple fractures create more surface area in direct communication with the wellbore. As a consequence, a greater volume of fluid can be produced from the wellbore per unit time. While fracture treatments continue to be designed using the best tools and techniques available, geometry estimates from fracture models have been difficult to verify. Pressure transient analysis is one of the fracture diagnostic techniques available to fill this knowledge gap, improving our understanding of hydraulic fracture behavior. It is an excellent calibration tool because it lets us evaluate the effective length of the fracture, and determine the appropriate length to use in history matching. Also, regardless of the application, identifying and understanding fracture complexities can lead to improved treatment designs, better completion strategies, and the potential for significant economic rewards through improved well performance and/or reduced completion cost.

This thesis investigates the turbine performance of a particular tidal energy conversion device analysing the hydrodynamic variables based on computational fluid dynamics simulations. Renewable tidal energy technology is undergoing a rapid development due to its advantages and new and creative designs of marine current turbines which are constantly being studied and improved. As a result, incorporating diffusers to accelerate the flow is a method used to increase the efficiency of the turbines. However, this practice has to be evaluated and parameterised to ensure its viability. Therefore, an experimental test of a ducted turbine, carried out in 2010, was selected for analysis with the aim of improving diffuser efficiency without studying the diffuser design but other variables in the system. The advantage of this strategy applied to a particular case is that the knowledge achieved can be used to benefit any diffuser design on many tidal turbines. The diffuser that was used in the 2010 experiment exhibited a low increment in power extracted and the main objective of this thesis arises from the question of how it could be possible to extract much more power using such ducted turbine with the same rotor and diffuser because the interaction of device components and characteristics of water flow causes an impact on the flow field, and therefore in extraction of energy. A methodology based on two hypotheses was developed to understand the influence of diffuser over the flow. The hypotheses addressed two areas: effects produced by a strut characteristic of turbine design and influence of the free surface.

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. 

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.

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.

Power conversion systems are becoming fundamental with the increasing power generation from renewable energy sources due to global warming and energy security concerns. In particular, wind energy systems require advance power converter devices to be able to supply power to the electric network or remote isolated areas in an effective way. A practical approach to these devices is required to fully comprehend their principles of operation and how they are integrated with the expanding renewable electricity production. This thesis describes the design and construction process of an inverter and a DC-DC converter, part of the AC-DC-AC link required to connect a laboratory model of a variable speed wind power system to the grid or to an isolated load.

Actualmente los sistemas de control de riego SCADA son diseñados con modelos y protocolos que dependen exclusivamente de cada fabricante. Si se requiere una interoperabilidad a nivel de programación de riegos y estado real de actuadores y sensores, con algún sistema de gestión que no sea del mismo fabricante, significa una alta inversión económica y tecnológica, que en la mayoría de casos no es posible realizar. Adicionalmente los mecanismos de diagnóstico de fallos actuales, no permiten determinar los fallos que se presentan en los sensores, lo cual se vuelve crítico cuando se presenta una anomalía en el sistema y no se puede cumplir con una demanda de riego exigida. La finalidad principal de esta tesis es contribuir a la estandarización de los sistemas de control de riego y a la integración de mecanismos de diagnóstico de fallos avanzados. Para ello y partiendo de un caso de estudio de un sistema de control de riego piloto, la memoria se encuentra constituida por las siguientes tres partes: En la primera, se propone un modelo de procesos que pretende estandarizar los sistemas de control de riego y su interoperabilidad con sistemas de gestión. Todo esto bajo las normativas ISA-88 e ISA-95 y la especificación XML del ISA-88: Batch-ML. En este punto la tesis trata la descripción de los modelos físicos, de procedimientos y de procesos de sistemas de control de riego, por medio del lenguaje de marcas extensibles (XML), centrándose principalmente en la programación de órdenes de riego y en la determinación en tiempo real del estado de los dispositivos del sistema. Para validar dicha descripción, en la segunda parte se presenta la implementación de un software prototipo que supervisa y controla, por medio del protocolo industrial OPC, un sistema de control de riego piloto que actualmente pertenece al grupo de investigación CEPIMA (Centre d´Enginyeria de Processos i Medi Ambient) de la UPC, el cual colabora como socio académico del grupo de empresas públicas TRAGSA. Finalmente en la tercera parte, se realiza un estudio del diagnóstico de fallos del sistema - caso de estudio, partiendo de la problemática que este tipo de sistemas conlleva, al sólo poder determinar automáticamente los fallos que se presentan en las válvulas más no en los sensores de caudal existentes en el sistema. Por lo tanto se plantea utilizar una técnica de diagnóstico de fallos a nivel estructural, que permite detectar y aislar los fallos desde el análisis del comportamiento del mismo sistema. Todo esto desde el enfoque FDI.

Mobile devices and theri applications continue increasing at a fast rate. Android is the leading mobile operating system, with more than 1 billion active devices worldwide. In order to improve the quality of Android applications, we must explore and nd cost-e cient solutions to automate part of their testing process. GUI Ripping is a technique that allows a systematic and automated exploration of an application's Graphical User Interface (GUI). During this exploration, test cases are generated and executed. To evaluate GUI Ripping, I conducted an empirical experiment using GUI Ripper and the Monkey. The e ciency of these testing tools was evaluated, comparing the code coverage and the number of faults detected on two Android applications.The experiment results showed the better e ciency of GUI Ripping, achieving higher code coverage and fault detection rate.