Diseño de filtros de onda acústica basados en estructuras "half lattice"

En los últimos tiempos la telefonía móvil ha experimentado una reducción de los terminales gracias a la miniaturización de los filtros a frecuencias de microondas. Los filtros pasa banda más utilizados son los basados en la tecnología SAW, sin embargo son incompatibles con tecnologías de silicio y su comportamiento se degrada a frecuencias superiores de 3 GHz, por ello los estudios actuales se centran en la tecnología BAW. Las dos arquitecturas convencionales de filtros basados en resonadores BAW unidos eléctricamente son el ladder y lattice. Sin embargo, en este proyecto se estudiará la topología half lattice, la cual presenta un mejor comportamiento y unas dimensiones más reducidas. Para ello se obtendrán las ecuaciones de diseño del filtro, y con ellas se realizará la implementación a partir de la frecuencia central y el ancho de banda relativo.

New trends in world wine consumption and its impact on the Spanish wineries during the second half of the twentieth century

The main goal of this research is explain the impact of the new trends of wine consumption, and the way these enterprises adapted to the circumstances. The hypothesis is that the Spanish companies had to start a deep and traumatic restructuring process, with the aim of surviving adequately in the changeable wine national and international markets. Heavy technological investments were made, with serious finance problems, during the eighties and nineties. We will see this from two specific cases, the Cooperatives "San Isidro" and "Rosario", located in the Region of Murcia, in the Spanish southeast.

Non-characteristic half-lives in radioactive decay

Half-lives of radionuclides span more than 50 orders of magnitude. We characterize the probability distribution of this broad-range data set at the same time that explore a method for fitting power-laws and testing goodness-of-fit. It is found that the procedure proposed recently by Clauset et al. [SIAM Rev. 51, 661 (2009)] does not perform well as it rejects the power-law hypothesis even for power-law synthetic data. In contrast, we establish the existence of a power-law exponent with a value around 1.1 for the half-life density, which can be explained by the sharp relationship between decay rate and released energy, for different disintegration types. For the case of alpha emission, this relationship constitutes an original mechanism of power-law generation.

Computing hypergraph width measures exactly

Hypergraph width measures are a class of hypergraph invariants important in studying the complexity of constraint satisfaction problems (CSPs). We present a general exact exponential algorithm for a large variety of these measures. A connection between these and tree decompositions is established. This enables us to almost seamlessly adapt the combinatorial and algorithmic results known for tree decompositions of graphs to the case of hypergraphs and obtain fast exact algorithms. As a consequence, we provide algorithms which, given a hypergraph H on n vertices and m hyperedges, compute the generalized hypertree-width of H in time O*(2n) and compute the fractional hypertree-width of H in time O(1.734601n.m).1

Full informatiu. Pla per la millora de la fertilització agrària. Comarques gironines. Octubre de 2010. Núm. 4. Cultius extensius

La fertilització dels cultius es basa en aportar al sòl els nutrients (dosi i moment adequat) que permetin obtenir la màxima producció, minimitzant les afeccions al medi i complint la legislació vigent. En cultius extensius es poden aportar nutrients en fons (pre-sembra) i/o cobertora ( cultiu en creixement). En cobertora, l’eficiència és major en estar proper el moment de màximes necessitats.

Full label space reduction in MPLS networks: asymmetric merged tunneling

Traffic Engineering objective is to optimize network resource utilization. Although several works have been published about minimizing network resource utilization in MPLS networks, few of them have been focused in LSR label space reduction. This letter studies Asymmetric Merged Tunneling (AMT) as a new method for reducing the label space in MPLS network. The proposed method may be regarded as a combination of label merging (proposed in the MPLS architecture) and asymmetric tunneling (proposed recently in our previous works). Finally, simulation results are performed by comparing AMT with both ancestors. They show a great improvement in the label space reduction factor

Probability distribution of the radionuclide half-lives

Power law distributions, a well-known model in the theory of real random variables, characterize a wide variety of natural and man made phenomena. The intensity of earthquakes, the word frequencies, the solar ares and the sizes of power outages are distributed according to a power law distribution. Recently, given the usage of power laws in the scientific community, several articles have been published criticizing the statistical methods used to estimate the power law behaviour and establishing new techniques to their estimation with proven reliability. The main object of the present study is to go in deep understanding of this kind of distribution and its analysis, and introduce the half-lives of the radioactive isotopes as a new candidate in the nature following a power law distribution, as well as a \canonical laboratory" to test statistical methods appropriate for long-tailed distributions.

Full Exploration of the Diels–Alder Cycloaddition on Metallofullerenes M3N@C80 (M=Sc, Lu, Gd): The D5h versus Ih Isomer and the Influence of the Metal Cluster

In this work a detailed investigation of the exohedral reactivity of the most important and abundant endohedral metallofullerene (EMF) is provided, that is, Sc3N@Ih-C80 and its D5h counterpart Sc3N@D5h-C80, and the (bio)chemically relevant lutetium- and gadolinium-based M3N@Ih/D5h-C80 EMFs (M=Sc, Lu, Gd). In particular, we analyze the thermodynamics and kinetics of the Diels–Alder cycloaddition of s-cis-1,3-butadiene on all the different bonds of the Ih-C80 and D5h-C80 cages and their endohedral derivatives. First, we discuss the thermodynamic and kinetic aspects of the cycloaddition reaction on the hollow fullerenes and the two isomers of Sc3N@C80. Afterwards, the effect of the nature of the metal nitride is analyzed in detail. In general, our BP86/TZP//BP86/DZP calculations indicate that [5,6] bonds are more reactive than [6,6] bonds for the two isomers. The [5,6] bond D5h-b, which is the most similar to the unique [5,6] bond type in the icosahedral cage, Ih-a, is the most reactive bond in M3N@D5h-C80 regardless of M. Sc3N@C80 and Lu3N@C80 give similar results; the regioselectivity is, however, significantly reduced for the larger and more electropositive M=Gd, as previously found in similar metallofullerenes. Calculations also show that the D5h isomer is more reactive from the kinetic point of view than the Ih one in all cases which is in good agreement with experiments

Sistema de votació electrònica sobre corbes el·líptques amb mescla de vots mitjançant Random Group Full Checking

L'objectiu del treball és dissenyar i implementar un sistema de simulació de votació electrònica, emprant una adaptació sobre corbes el·líptiques del criptosistema ElGamal, per tal d'estudiar-ne la viabilitat, centrant l'atenció en temes de seguretat, especialment en el procés de mescla de vots per tal de desvincular un vot de la persona que l'ha emès.