Stochastic volatility models and the Taylor effect

It has been often empirically observed that the sample autocorrelations of absolute financial returns are larger than those of squared returns. This property, know as Taylor effect, is analysed in this paper in the Stochastic Volatility (SV) model framework. We show that the stationary autoregressive SV model is able to generate this property for realistic parameter specifications. On the other hand, the Taylor effect is shown not to be a sampling phenomena due to estimation biases of the sample autocorrelations. Therefore, financial models that aims to explain the behaviour of financial returns should take account of this property

The armenian genocide: background, process and consequences

RESUMEN: Este trabajo examina los hechos ocurridos en el Imperio otomano entre los años 1915 y 1918, que se corresponden con el primer genocidio moderno del siglo XX. Es necesario contextualizar el proceso, aludiendo a las causas que provocaron el auge del nacionalismo turco y el odio exacerbado hacia los armenios, que finalmente terminaron en la ejecución de un plan estatal para la eliminación de la minoría armenia otomana. Tras la consecución de la “causa armenia”, la política turca se caracterizó por un negacionismo radical que aún perdura y que ha impedido durante muchos años el reconocimiento internacional del genocidio, así como negar a los propios armenios su memoria.ABSTRACT: This project examines the events that took place in the Ottoman Empire between 1915 and 1918, which corresponds to the first modern genocide of the 20th century. It is necessary to contextualize the process, to allude to the causes that provoke the rise of Turkish nationalism and the exacerbated hatred of Armenians, which will finally end in the execution of a state plan for the elimination of the Ottoman Armenian minority. After the achievement of the "Armenian cause", the Turkish policy was characterized by a radical denialism that still persists and that has prevented for many years the international recognition of the genocide, as well as denying the Armenians themselves their memoryGrado en Histori

The Dictatorship of Primo de Rivera: Unión Patriótica and the Somatén

RESUMEN: Este trabajo examina la dictadura de Primo de Rivera, concretamente las dos instituciones claves utilizadas por el dictador para movilizar a las masas, llevar a cabo la labor de institucionalización del régimen y acometer la proyección constitucional necesaria. Estas son la Unión Patriótica, partido único creado por Primo de Rivera para poner en marcha sus decisiones políticas y el Somatén, una suerte de policía armada defensora del orden social y los valores considerados óptimos por la dictadura.ABSTRACT: This project examines the Dictatorship of Primo de Rivera, specifically, the two key institutions used by the dictator to mobilize the masses, carry out the work of institutionalizing the regime and undertaking the necessary constitutional projection. These are the Unión Patriótica, a single party created by Primo de Rivera to implement his political decisions, and the Somatén, a kind of armed police defending social order and the values considered optimal by the dictatorship.Máster en Historia Contemporáne

A self-calibration circuit for a neural spike recording channel

This paper presents a self-calibration circuit for a neural spike recording channel. The proposed design tunes the bandwidth of the signal acquisition Band-Pass Filter (BPF), which suffers from process variations corners. It also performs the adjustment of the Programmable Gain Amplifier (PGA) gain to maximize the input voltage range of the analog-to-digital conversion. The circuit, which consists on a frequency-controlled signal generator and a digital processor, operates in foreground, is completely autonomous and integrable in an estimated area of 0.026mm 2 , with a power consumption around 450nW. The calibration procedure takes less than 250ms to select the configuration whose performance is closest to the required one.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

A power efficient neural spike recording channel with data bandwidth reduction

This paper presents a mixed-signal neural spike recording channel which features, as an added value, a simple and low-power data compression mechanism. The channel uses a band-limited differential low noise amplifier and a binary search data converter, together with other digital and analog blocks for control, programming and spike characterization. The channel offers a self-calibration operation mode and it can be configured both for signal tracking (to raw digitize the acquired neural waveform) and feature extraction (to build a first-order PWL approximation of the spikes). The prototype has been fabricated in a standard CMOS 0.13μm and occupies 400μm×400μm. The overall power consumption of the channel during signal tracking is 2.8μW and increases to 3.0μW average when the feature extraction operation mode is programmed.Ministerio de Ciencia e Innovación TEC2009-08447Junta de Andalucía TIC-0281

A new 2D tessellation for angle problems: The polar diagram

The new approach we propose in this paper is a plane partition with similar features to those of the Voronoi Diagram, but the Euclidean minimum distance criterion is replaced for the minimal angle criterion. The result is a new tessellation of the plane in regions called Polar Diagram, in which every site is owner of a polar region as the locus of points with smallest polar angle respect to this site. We prove that polar diagrams, used as preprocessing, can be applied to many problems in Computational Geometry in order to speed up their processing times. Some of these applications are the convex hull, visibility problems, and path planning problems

Estudio de técnicas de planificación dinámica de planes de ocio

Este proyecto, 'Olétrip', es la continuación de una versión anterior cuyos autores fueron Raquel Álvarez Hernández, Qiang Sun y YanYan Cheng. Nuestro objetivo en el proyecto es mejorar las recomendaciones de un sistema de planes de ocio usando diferentes algoritmos para calcular las rutas más óptimas con la ayuda de un validador personalizado. Los algoritmos nuevos implementados en la aplicación son los siguientes: • Algoritmo aleatorio: se implementó para ayudarnos a familiarizarnos con el código heredado del proyecto anterior, y posteriormente resultó útil para la implementación del algoritmo genético. • Algoritmo de primero el mejor (BFS): se usa para la búsqueda de la ruta más corta después de que el usuario haya especificado todos los detalles del viaje. • Algoritmo genético: este algoritmo se realizó con la idea de construir un plan óptimo, a pesar de saber que requiere de bastante tiempo y consumo de recursos... pero finalmente se optó por ese algoritmo para los viajeros que saben a qué ciudad quieren ir pero que no saben qué visitar. Se explicará las ventajas y desventajas que nos supone optar por un algoritmo u otro, el cómo se ha implementado cada uno de ellos y los cambios que han sido necesarios abordar con respecto a la anterior versión del proyecto. Incorporaremos a Olétrip un validador de planes que se encargará en la parte del backend de considerar la eficiencia que tiene un plan partiendo de unos requisitos que hemos definido. Será de gran importancia esta nueva funcionalidad de validación ya que los algoritmos implementados manejan una cantidad importante de planes y de esta manera nos ayuda a evaluar qué planes son más eficientes. La interfaz utilizada será la misma que en su anterior versión, incorporando una interfaz nueva que sirve para el recomendar de planes a los usuarios indecisos. También hemos incorporado un simulador de planes para los usuarios Admin que ayuda a la hora de implementar alguna funcionalidad nueva en la aplicación. De esta manera realizaremos una serie de evaluaciones con el usuario realizando un estudio de los distintos algoritmos, analizando así los resultados obtenidos y la satisfacción del usuario

Hybrid layers of etch-and-rinse versus self-etching adhesive systems

Objective: To evaluate the effectiveness in the formation of resin tags, adhesive lateral branches and hybrid layers of five adhesive systems, when bonding to dentine. Material and Methods: Flat dentin surfaces from 25 molars were bonded with several adhesive systems according to the manufacturers? instructions. Composite build-ups were constructed incrementally with Tetric Ceram. The Specimens were sectioned parallel to the long axis. One section was treated with phosphoric acid and sodium hypochlorite in order to reveal the hybrid layer formation. The other section was stored in 30% hydrochloric acid to detect resin tags and adhesive lateral branch formation. Results: The two etch-and-rinse self-priming adhesives exhibited thicker hybrid layers than those found in self-etching adhesive systems. The all-in-one adhesive showed droplet formation between the adhesive and the resin composite. The resin tags formed with the etch-and-rinse adhesives were much longer than those found with the self-etching adhesives. Lateral branch formation was observed in etch-and-rinse adhesives and in one of the self-etch adhesives Clearfil SE Bond (SEB). Conclusion: The formed hybrid layer obtained with the two-step selfetching adhesives and the etch-and-rinse systems were continuous and uniform in thickness. Droplets within the all-in-one adhesive layer may occur as a result of water absorption from dentin through osmosis, and may interfere with proper resin polymerization. Resin tags obtained with SEB and the etch-and-rinse adhesive systems showed lateral branches, which is a sign of proper resin infiltration

Thermal isostasy on Mars

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu