Pitch Based Wind Turbine Intelligent Speed Setpoint Adjustment Algorithms

This work is aimed at optimizing the wind turbine rotor speed setpoint algorithm. Several intelligent adjustment strategies have been investigated in order to improve a reward function that takes into account the power captured from the wind and the turbine speed error. After different approaches including Reinforcement Learning, the best results were obtained using a Particle Swarm Optimization (PSO)-based wind turbine speed setpoint algorithm. A reward improvement of up to 10.67% has been achieved using PSO compared to a constant approach and 0.48% compared to a conventional approach. We conclude that the pitch angle is the most adequate input variable for the turbine speed setpoint algorithm compared to others such as rotor speed, or rotor angular acceleration.

Analysis of the housing market in the autonomous community of the Basque country: the adjustment after the burst of the housing bubble

In this project study the characteristic and dynamics of the residential housing market in the Basque country. When strong expansion and colapsing emerged in 2007,studied the differents adjustment.

The Ohlin-Keynes Debate on the German Interwar Reparations Revisited

This paper analyzes the debate between Ohlin and Keynes on the question as to whether Germany was able to make the payments specified in the Dawes Plan. Keynes argued that Germany was able to collect the money but unable to transfer it to the victors because there existed an insurmountable “transfer problem”. Ohlin replied that such a “transfer problem” did not exist and, therefore, that Germany was able to make the payments stipulated by the Dawes Committee. This paper analyzes the positions of the two contenders and argues that the problems are not correctly delimited and that the theoretical bases of the contenders show serious deficiencies. It also brings to light some interesting theoretical and practical paradoxes that neither Keynes nor Ohlin dealt with.

Another Look to the Price-Dividend Ratio: A Markov-Switching Approach

This paper analyzes the stationarity of this ratio in the context of a Markov-switching model à la Hamilton (1989) where an asymmetric speed of adjustment is introduced. This particular specification robustly supports a nonlinear reversion process and identifies two relevant episodes: the post-war period from the mid-50’s to the mid-70’s and the so called “90’s boom” period. A three-regime Markov-switching model displays the best regime identification and reveals that only the first part of the 90’s boom (1985-1995) and the post-war period are near-nonstationary states. Interestingly, the last part of the 90’s boom (1996-2000), characterized by a growing price-dividend ratio, is entirely attributed to a regime featuring a highly reverting process.

Option-Implied Preferences Adjustments and Risk-Neutral Density Forecasts

The main objective of this paper is to analyse the value of information contained in prices of options on the IBEX 35 index at the Spanish Stock Exchange Market. The forward looking information is extracted using implied risk-neutral density functions estimated by a mixture of two-lognormals and three alternative risk-adjustments: the classic power and exponential utility functions and a habit-based specification that allows for a counter-cyclical variation of risk aversion. Our results show that at four-week horizon we can reject the hypothesis that between October 1996 and March 2000 the risk-neutral densities provide accurate predictions of the distributions of future realisations of the IBEX 35 index at a four-week horizon. When forecasting through risk-adjusted densities the performance of this period is statistically improved and we no longer reject that hypothesis. All risk-adjusted densities generate similar forecasting statistics. Then, at least for a horizon of four-weeks, the actual risk adjustment does not seem to be the issue. By contrast, at the one-week horizon risk-adjusted densities do not improve the forecasting ability of the risk-neutral counterparts.

Respuesta a la sequía de Pinus radiata D. Don y su implicación en los procesos de tolerancia

160 p. (Bibliogr. 141-160)

An Alternative View of the US Price-Dividend Ratio Dynamics

As a necessary condition for the validity of the present value model, the price-dividend ratio must be stationary. However, significant market episodes seem to provide evidence of prices significantly drifting apart from dividends while other episodes show prices anchoring back to dividends. This paper investigates the stationarity of this ratio in the context of a Markov- switching model à la Hamilton (1989) where an asymmetric speed of adjustment towards a unique attractor is introduced. A three-regime model displays the best regime identification and reveals that the first part of the 90’s boom (1985-1995) and the post-war period are characterized by a stationary state featuring a slow reverting process to a relatively high attractor. Interestingly, the latter part of the 90’s boom (1996-2000), characterized by a growing price-dividend ratio, is entirely attributed to a stationary regime featuring a highly reverting process to the attractor. Finally, the post-Lehman Brothers episode of the subprime crisis can be classified into a temporary nonstationary regime.

Una aproximación al sector eléctrico

Español:Este TFG pretende exponer de un modo sencillo el mercado eléctrico español. Se trata de un tema de elevada complejidad y gran extensión. Con el fin de alcanzar una idea clara, hemos decidido centrarnos en los puntos de mayor relevancia. En las secciones siguientes abordamos cuestiones relativas al mercado mayorista (pool) y minorista español así como la incipiente reforma eléctrica llevada a cabo por el Gobierno. Después de una breve Introducción, la sección 2 enumera una serie de términos que se utilizan con frecuencia en esta área. La sección 3 proporciona algunos antecedentes sobre el sector eléctrico. La sección 4 se refiere al mercado mayorista, en el cual se realiza la compra-venta diaria de electricidad. En él participan los productores, los distribuidores y los comercializadores de electricidad, así como los consumidores cualificados de energía eléctrica. Dentro de éste nos encontramos el mercado a plazo (o forward), el mercado diario (o spot) y el mercado a corto plazo (o de ajuste). La sección 5 trata del mercado minorista, su diseño y composición. Aquí, las empresas encargadas de comercializar energía (que compran en el mercado mayorista a las empresas generadoras) se la venden a los consumidores finales. En la sección 6 se aborda la Reforma Eléctrica, aclarando los cambios sufridos desde su implantación. Los hechos más llamativos a este respecto son: la eliminación de las subastas CESUR y el cambio de la Tarifa de Último Recurso (TUR) a un Precio Voluntario para el Pequeño Consumidor (PVPC). Por último, hay una sección final con las principales conclusiones.

Spinal circuits can accommodate interaction torques during multijoint limb movements

The dynamic interaction of limb segments during movements that involve multiple joints creates torques in one joint due to motion about another. Evidence shows that such interaction torques are taken into account during the planning or control of movement in humans. Two alternative hypotheses could explain the compensation of these dynamic torques. One involves the use of internal models to centrally compute predicted interaction torques and their explicit compensation through anticipatory adjustment of descending motor commands. The alternative, based on the equilibrium-point hypothesis, claims that descending signals can be simple and related to the desired movement kinematics only, while spinal feedback mechanisms are responsible for the appropriate creation and coordination of dynamic muscle forces. Partial supporting evidence exists in each case. However, until now no model has explicitly shown, in the case of the second hypothesis, whether peripheral feedback is really sufficient on its own for coordinating the motion of several joints while at the same time accommodating intersegmental interaction torques. Here we propose a minimal computational model to examine this question. Using a biomechanics simulation of a two-joint arm controlled by spinal neural circuitry, we show for the first time that it is indeed possible for the neuromusculoskeletal system to transform simple descending control signals into muscle activation patterns that accommodate interaction forces depending on their direction and magnitude. This is achieved without the aid of any central predictive signal. Even though the model makes various simplifications and abstractions compared to the complexities involved in the control of human arm movements, the finding lends plausibility to the hypothesis that some multijoint movements can in principle be controlled even in the absence of internal models of intersegmental dynamics or learned compensatory motor signals.

NAFTA Itunaren ondorioak Mexikoko ekonomian

The objective of this Final Project focuses on explaining how the North American Free Trade Agreement (NAFTA) has affected the economy of Mexico. To achieve this, we have conducted a documentary research based on analysis of existing general and specific scientific literature on the subject from the objectives and hypotheses a priori. The framework is divided into several sections where the following issues are addressed: the processes of negotiation and adjustment plans that occurred before to signing the agreement; the aim and purpose of the agreement; the consequences of the covenant in the economy of Mexico, considering the decomposition of the status and importance of immigration; and finally, an analysis of the current situation of Mexico. This paper concludes with a set of final thoughts with hypothesis testing, and a theory about how different countries should cooperate in order to have a beneficial development in all parties.

Programas de fidelización en la distribución comercial de la era digital.

Hoy en día, las empresas deben adaptarse a los cambios continuos del mercado, donde el comercio electrónico crece cada año y las redes sociales y los dispositivos móviles conectan a los consumidores con las marcas. El marketing ha evolucionado gracias a las nuevas tecnologías de información y comunicación para responder a un consumidor social que está conectado gran parte del día, es exigente y además, está comprometido con el medio ambiente. En un entorno muy maduro y competitivo, el cliente se ha convertido en el activo más valorado para las empresas especialmente de distribución minorista y por eso, su fidelización es un objetivo prioritario para las compañías, quienes tratan de enfocar las estrategias de marketing hacia las relaciones con los consumidores. Pero, a pesar de la infinidad de oportunidades que ofrecen las nuevas tecnologías, los programas de fidelización implantados en el entorno digital tienen un recorrido de necesaria evolución y un ajuste de mejoras para la adaptación de un medio poco estructurado a las nuevas circunstancias. A través de este trabajo fin de grado se propone dar a conocer la actualidad sobre la distribución comercial en el ámbito digital así como las tendencias en los programas de fidelización. Además, la creciente implicación en el cuidado del medio ambiente por parte de las empresas y los consumidores se incluye como una aportación original y distintiva al trabajo.

Energy retrofits in social housing. Analysis of its thermal behaviour.

468 p.