Universitarios y prensa en Galicia: hábitos declarados y preferencias informativas

La presente investigación se inicia con objeto de conocer los hábitos de consumo y adquisición de prensa en papel por parte de los universitarios gallegos. Su interés resulta de especial relevancia, teniendo en cuenta que se trata de un target muy específico (entre 18 y 25 años, en periodo de formación superior), en un contexto mediático de especial interés (despegue de los medios electrónicos, irrupción de la prensa gratuita, programación televisiva de cuestionada calidad, etc.). Los resultados obtenidos permiten realizar una lectura que aporta los datos que definen sus preferencias mediáticas y sus hábitos de consumo informativo.The current investigation pretends to know the habits of press consumption and acquisition from the university students in Galicia. His interest is of special significance, considering that this is a very specific target (between 18 and 25 years, university education), in an interesting given media context (boom of electronic media, arrival of free newspapers, TV programming whose quality is criticized, etc. Thanks to the results of this work, we will contribute some clues about their informative habits and preferences

Molecular modification of coumarin dyes for more efficient dye sensitized solar cells

solo para uso personalIn this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (–OH, –NH2, and –OCH3) and two different substituents with steric effect: –CH2–CH2–CH2– and –CH2–HC=CH–. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the new dyes. The introduction of a –NH2 group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of –CH2–CH2–CH2– does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, –CH2– HC=CH– produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.Ministerio de Ciencia e Innovación de España-MAT2008-4918 y CSD2008-002

Design of an Efficient Interconnection Network of Temperature Sensors

Temperature has become a first class design constraint because high temperatures adversely affect circuit reliability, static power and degrade the performance. In this scenario, thermal characterization of ICs and on-chip temperature monitoring represent fundamental tasks in electronic design. In this work, we analyze the features that an interconnection network of temperature sensors must fulfill. Departing from the network topology, we continue with the proposal of a very light-weight network architecture based on digitalization resource sharing. Our proposal supposes a 16% improvement in area and power consumption compared to traditional approache

Modelado 3D para impresión de una serie configurable de figuras de acción

[ES] La tesina, a propuesta del alumno, se centra en el modelado mediante diferentes programas 3D de varias figuras de acción, así como de distintos elementos configurables que se les pueda añadir o cambiar por otros, como armas, accesorios o elementos del escenario. La idea es explorar una metodología de trabajo que permita generar una variedad de personajes mediante la combinación de elementos.[EN] A proposal from the student, the thesis focuses on the modeling process, through different 3D programs, of several action figures, as well as different configurable elements that can be added or changed by others, such as weapons, accessories or stage elements. The idea is to explore a work methodology that allows generating a variety of characters through the combination of elements.López Sánchez, M. (2019). Modelado 3D para impresión de una serie configurable de figuras de acción. Universitat Politècnica de València. http://hdl.handle.net/10251/143059TFG

Preparación y caracterización de materiales compuestos en forma de films de PMMA relleno con partículas submicrométricas de Titanato de Bario

En la actualidad los materiales compuestos de matriz polimérica rellenos con nanopartículas inorgánicas están recibiendo mucha atención. La razón es que aúnan las propiedades típicas de los materiales cerámicos con la ventaja de que se pueden tener un procesado más fácil y económico, típico de los polímeros. Estos materiales compuestos deben tener una adecuada dispersión de partículas dentro de la matriz polimérica, en caso contrario la formación de agregados e incluso aglomerados puede dar lugar a propiedades finales (eléctricas o mecánicas) no deseadas. Por ejemplo, se pueden generar variaciones microscópicas de la permitividad eléctrica que puedan incrementar el campo eléctrico localmente produciendo descargas parciales Además, en el caso de los materiales compuestos en los que un polímero está relleno de nanopartículas, la interfase adquiere un papel muy importante a la hora de inducir cambios en las propiedades observadas, de ahí que muchos investigadores la traten como un tercer constituyente del material compuesto. Se considera interfase a la región que rodea a cada partícula, en la existe un gradiente de propiedades entre el polímero y el relleno o refuerzo. En dicha región la dinámica de las cadenas poliméricas puede ser alterada debido al contacto estrecho con la superficie del relleno (lo que daría lugar a una movilidad restringida o mejorada). La primera parte de este proyecto ha sido diseñar y optimizar un proceso de fabricación de películas de polimetilmatacrilato (PMMA) relleno con diferentes porcentajes en peso de nanopartículas de Titanato de Bario, de manera que se alcance una buena de dispersión de partículas y se obtengan unos espesores uniformes1. La segunda parte busca caracterizar el material compuesto, prestando especial atención al estudio de la dinámica molecular del polímero bajo la influencia de la presencia de las partículas de BT. Para ello se estudiarán todas las relajaciones térmicas del PMMA (temperatura de transición vítrea) mediante DSC. Además, y con el objetivo de obtener más información acerca de los procesos que puedan ocurrir en el material compuesto durante esta transición, se ha realizado el seguimiento de la fluorescencia una sonda fluorescente (Dansil Cadaverina), que se halla inmersa en el polímero. Su emisión, medida con espectroscopia de fluorescencia, es tan sensible a los cambios en sus alrededores más inmediatos, que una muy pequeña cantidad basta para obtener información a nanoescala de los materiales en los que está inmersa, tales como variaciones en el volumen libre y posibles tensiones transmitidas a través de la interfase como consecuencia de cambios que en el refuerzo con la temperatura, como por ejemplo en el tamaño de sus partículas al pasar su temperatura de Curie (cambio de la fase tetragonal del BT a la fase cúbica). Para terminar con la caracterización de los materiales preparados se realizará un estudio de termodegradación por análisis termogravimétrico, TGA, y estudio morfológico (análisis de la dispersión de partículas en el interior de la matriz polimérica) mediante microscopía electrónica de barrido, SEM.Recently, nanocomposites based on polymer and inorganic nanoparticles have received a lot of attention due to their optimal mixture of typical ceramic materials properties with an easier processing typical from polymers. These composites must have an appropriate dispersion of nanoparticles within the polymer matrix; otherwise undesired effects may appear due the formation of agglomerates, such as slightly microscopic variations of permittivity that can increase locally the electrical field yielding to local discharges. Composite materials are made of a polymer matrix and its reinforcement. Additionally on nanocomposites, the interphase plays an important role on inducing important changes on the properties observed, and is also considered as part of the constituents. The interphase is defined as the area which surrounds each particle where the polymer chain dynamics may be altered due to intimate contact with nanoparticles (resulting in restricted or enhanced mobility), plus the surrounding matrix influenced by the immediate layer. The first part of this project is to design and optimize a fabrication of PMMA film with different quantities of barium titanate nanoparticles, in order to achieve a good dispersion within the polymer matrix and a homogeneous thickness. The second part is about composite characterization, specially focused on finding the glass transition temperature, by DSC. This temperature is relevant because after it significant changes on material morphology are shown, and therefore changes on its properties.. Additionally, and with the aim of obtaining more information about internal processes that may happen within the composite along this transition, a fluorescence label has been attached to the composite. This label is located immersed within the polymer matrix and its emission, measured with fluorescence spectroscopy, is so sensitive to any change on its surroundings, that only with a small quantity is enough to obtain a nanoescale information such a free volume variations and possible stressed transmitted across the interface as a consequence of changes on the filler with temperature (particle size changes). Finally, to complete a fully characterization and observe with more detail nanoparticles dispersion, measures have been taking using TGA and SEM.Ingeniería Industria

Generative capacities of cellular automata codification for evolution of NN codification

Proceeding of: International Conference on Artificial Neural Networks. ICANN 2002, Madrid, Spain, August 28-30, 2002Automatic methods for designing artificial neural nets are desired to avoid the laborious and erratically human expert’s job. Evolutionary computation has been used as a search technique to find appropriate NN architectures. Direct and indirect encoding methods are used to codify the net architecture into the chromosome. A reformulation of an indirect encoding method, based on two bi-dimensional cellular automata, and its generative capacity are presented.Publicad

Non-Direct Encoding Method Based on Cellular Automata to Design Neural Network Architectures

Architecture design is a fundamental step in the successful application of Feed forward Neural Networks. In most cases a large number of neural networks architectures suitable to solve a problem exist and the architecture design is, unfortunately, still a human expert’s job. It depends heavily on the expert and on a tedious trial-and-error process. In the last years, many works have been focused on automatic resolution of the design of neural network architectures. Most of the methods are based on evolutionary computation paradigms. Some of the designed methods are based on direct representations of the parameters of the network. These representations do not allow scalability; thus, for representing large architectures very large structures are required. More interesting alternatives are represented by indirect schemes. They codify a compact representation of the neural network. In this work, an indirect constructive encoding scheme is proposed. This scheme is based on cellular automata representations and is inspired by the idea that only a few seeds for the initial configuration of a cellular automaton can produce a wide variety of feed forward neural networks architectures. The cellular approach is experimentally validated in different domains and compared with a direct codification scheme.Publicad

Evolutionary cellular configurations for designing feed-forward neural networks architectures

Proceeding of: 6th International Work-Conference on Artificial and Natural Neural Networks, IWANN 2001 Granada, Spain, June 13–15, 2001In the recent years, the interest to develop automatic methods to determine appropriate architectures of feed-forward neural networks has increased. Most of the methods are based on evolutionary computation paradigms. Some of the designed methods are based on direct representations of the parameters of the network. These representations do not allow scalability, so to represent large architectures, very large structures are required. An alternative more interesting are the indirect schemes. They codify a compact representation of the neural network. In this work, an indirect constructive encoding scheme is presented. This scheme is based on cellular automata representations in order to increase the scalability of the method