L'experiència de les eleccions generals 2008

Les passades eleccions del 9 de març de 2008 han estat les primeres eleccions generals a Espanya on la Xarxa ha tingut un paper important en la campanya electoral. Internet ha entrat en campanya, i ha entrat de manera diferent a com ho havia fet fins ara, no només en unes eleccions generals, sinó en qualsevol elecció a Espanya. Tot i que els partits polítics han continuat tenint les seves pàgines web on es podien trobar notícies, biografia dels candidats, agenda d'actes, programa electoral, etc., s'observen cinc clars canvis en la manera de fer campanya a través de la Xarxa, canvis que també s'han produït en altres països

Noise reduction using wavelet cycle spinning: analysis of useful periodicities in the z-transform domain

Cycle spinning (CS) and a'trous algorithms are different implementations of the undecimated wavelet transform (UWT). Both algorithms can be used for UWT and even though the resulting wavelet coefficients are different, they keep a correspondence. This paper describes an analysis of the CS algorithm performed in the z-transform domain, showing the similarities and differences with the a'trous implementation. CS generates more wavelet coefficients than a'trous, but the number of significative and different coefficients is the same in both cases because of the occurrence of a periodic repetition in CS coefficients. Mathematical expressions for the relationship between CS and a'trous coefficients and for CS coefficient periodicities are provided in the z-transform domain. In some wavelet denoising applications, periodicities (present in the coefficients of the CS procedure) can also be found in the performance measure of the processed signals. In particular, in ultrasonic CS denoising applications, periodicities have been appreciated in the signal-to-noise ratio (SNR) of the ultrasonic denoised signals. These periodicities can be used to optimize the number of CS coefficients for an efficient implementation. Two examples showing the periodicities in the SNR are included. A selection of several reduced sets of CS wavelet coefficients has been utilized in the examples, and the SNRs resulting after denoising are analyzed.This work was partially supported by Spanish MCI Project DPI2011-22438 and MEC Project TIN2013-47272-C2-1-R. The translation of this paper was funded by the Universitat Politecnica de Valencia, Spain.Rodríguez-Hernández, MA.; San Emeterio, JL. (2016). Noise reduction using wavelet cycle spinning: analysis of useful periodicities in the z-transform domain. Signal, Image and Video Processing. 10(3):519-526. https://doi.org/10.1007/s11760-015-0762-8S519526103Daubechies, I.: Ten Lectures on Wavelets. SIAM, Philadelphia (1992)Mallat, S.: A Wavelet Tour of Signal Processing. Academic Press, New York (1999)Kovacevic, J., Goyal, V.K., Vetterli, M.: Signal Processing Fourier and Wavelet Representations. http://www.fourierandwavelets.org/SPFWR_a3.1_2012.pdf (2012)Burrus, C.S., Gopinath, R.A., Guo, H.: Introduction to Wavelets and Wavelet Transforms. Prentice-Hall, New Jersey (1998)Kamilov, U., Bostan, E., Unser, M.: Wavelet shrinkage with consistent cycle spinning generalizes total variation denoising. IEEE Signal Process. Lett. 19(4), 187–190 (2012)Kumar, B.K.S.: Image denoising based on non-local means filter and its method noise thresholding. Signal Image Video Process. 7, 1211–1227 (2013)Rezazadeh, S., Coulombe, S.: A novel discrete wavelet transform framework for full reference image quality assessment. Signal Image Video Process. 7, 559–573 (2013)Atto, A.M., Pastor, D., Mercier, G.: Wavelet shrinkage: unification of basic thresholding functions and thresholds. Signal Image Video Process. 5, 11–28 (2011)Yektaii, M., Ahmad, M.O., Bhattacharya, P.: A method for preserving the classifiability of digital images after performing a wavelet-based compression. Signal Image Video Process. 8, 169–180 (2014)Kanumuri, T., Dewal, M.L., Anand, R.S.: Progressive medical image coding using binary wavelet transforms. Signal Image Video Process. 8, 883–899 (2014)Kubinyi, M., Kreibich, O., Neuzil, J., Smid, R.: EMAT noise suppression using information fusion in stationary wavelet packets. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 58, 1027–1036 (2011)Abbate, A., Koay, J., Frankel, J., Schroeder, S.C., Das, P.: Signal detection and noise suppression using a wavelet transform signal processor: application to ultrasonic flaw detection. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 44, 14–26 (1997)Pardo, E., San Emeterio, J.L., Rodriguez, M.A., Ramos, A.: Noise reduction in ultrasonic NDT using undecimated wavelet transforms. Ultrasonics 44, e1063–e1067 (2006)Pardo, E., Emeterio, J.L., Rodriguez, M.A., Ramos, A.: Shift invariant wavelet denoising of ultrasonic traces. Acta Acust. United Acust. 94, 685–693 (2008)Shensa, M.J.: The discrete wavelet transform: wedding the a trous and Mallat algorithms. IEEE Trans. Signal Process. 40, 2464–2482 (1992)Coifman, R., Donoho, D.: Translation invariant de-noising. In: Antoniadis, A., Oppenheim, G. (eds.) Wavelets and Statistics, Lecture Notes in Statistics, pp. 125–150. Springer, Berlin (1995)Mallat, S.G.: A theory for multiresolution signal decomposition: the wavelet representation. IEEE Trans. Pattern Anal. Mach. Intell. 2, 674–693 (1989)Beylkin, G., Coifman, R., Rokhlin, V.: Fast wavelet transforms and numerical algorithms. Commun. Pure Appl. Math. 44, 141–183 (1991)Beylkin, G.: On the representation of operators in bases of compactly supported wavelets. SIAM J. Numer. Anal. 6(6), 1716–1740 (1992)Vaidyanathan, P.P.: Multirate Systems and Filter Banks. Prentice Hall, Englewood Cliffs (1992)Donoho, D.L., Johnstone, I.M.: Ideal spatial adaptation by wavelet shrinkage. Biometrika 81, 425–455 (1994)Donoho, D.L., Johnstone, I.M.: Adapting to unknown smoothness via wavelet shrinkage. J. Am. Stat. Assoc. 90, 1200–1224 (1995)Donoho, D.L., Johnstone, I.M., Kerkyacharian, G., Picard, D.: Wavelet shrinkage: Asymptotia? J. R. Stat. Soc. Ser. B 57, 301–369 (1995)Karpur, P., Shankar, P.M., Rose, J.L., Newhouse, V.L.: Split spectrum processing: optimizing the processing parameters using minimization. Ultrasonics 25, 204–208 (1997)Lazaro, J.C., San Emeterio, J.L., Ramos, A., Fernandez, J.L.: Influence of thresholding procedures in ultrasonic grain noise reduction using wavelets. Ultrasonics 40, 263–267 (2002)Donoho, D.L.: De-noising by soft thresholding. IEEE Trans. Inf. Theory 41, 613–627 (1995)Johnstone, I.M., Silverman, B.W.: Wavelet threshold estimators for data with correlated noise. J. R. Stat. Soc. 59, 319–351 (1997

Papilla preservation periodontal surgery in periodontal reconstruction for deep combined intra-suprabony defects. Retrospective analysis of a registry-based cohort

Suprabony defects are the most prevalent defects and there is very little evidence on their treatment. This study aims to assess the effectiveness of papilla preservation periodontal surgery in the periodontal reconstruction of combined deep intra-suprab

Direct Hydroxylation of Phenol to Dihydroxybenzenes by H2O2 and Fe-based Metal-Organic Framework Catalyst at Room Temperature

A semi-crystalline iron-based metal-organic framework (MOF), in particular Fe-BTC, that contained 20 wt.% Fe, was sustainably synthesized at room temperature and extensively characterized. Fe-BTC nanopowders could be used as an efficient heterogeneous catalyst for the synthesis of dihydroxybenzenes (DHBZ), from phenol with hydrogen peroxide (H2O2), as oxidant under organic solvent-free conditions. The influence of the reaction temperature, H2O2 concentration and catalyst dose were studied in the hydroxylation performance of phenol and MOF stability. Fe-BTC was active and stable (with negligible Fe leaching) at room conditions. By using intermittent dosing of H2O2, the catalytic performance resulted in a high DHBZ selectivity (65%) and yield (35%), higher than those obtained for other Fe-based MOFs that typically require reaction temperatures above 70◦C. The long-term experiments in a fixed-bed flow reactor demonstrated good Fe-BTC durability at the above conditionsThe authors thank the financial support by Consejo Nacional de Ciencia y Tecnología (CONACYT) for the grant number 764635 and the project 256296; and to TNM for the supporting project 5627.19.P. Also, to the Spanish Ministerio de Ciencia, Innovación y Universidades (MICINN) and FEDER program (EU) through the projects: CTM2016-76454-R (MICINN) and RTI2018-095052-B-I00 ((MCIU/AEI/FEDER, UE

Biomass derived activated carbon catalysts for the one-step dimethyl ether synthesis from syngas

Se trata de un resumen extendido de una comunicación a congreso internacional.In this work we study the behaviour of a carbon-based catalyst for this one-step synthesis process. Two kinds of activated carbons, prepared by chemical (with H3PO4) and physical (by CO2 partial gasification) activation of olive stones, were used as catalysts support. The main difference between the activated carbons was the presence of chemically stable phosphorus surface groups, mainly in form of C-O-PO3 groups1, on the activated carbon prepared via chemical activation. The addition of Zr to the chemically activated carbon (ACPZr) resulted in the formation of zirconium phosphate species on the carbon surface, which were capable of promoting the selective methanol dehydration to DME. Cu-Zn loading on the chemically activated carbon resulted in strong interactions between the metallic phase and the phosphate surface groups due to the formation Cu phosphate species. The bifunctional catalyst, ACPZrCuZn showed less conversion that the physical mixture. This fact is related with the presence of phosphorus species that avoids the reduction of the metal (copper).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Biaxial bending of slender hsc columns and tubes filled with concrete under short- and long-term loads: ii) verification

An analytical method that calculates both the short- and long-term response of slender columns made of high-strength concrete (HSC) and of tubes filled with concrete with generalized end conditions that are subjected to transverse loads along the span and to axial loads at the ends (causing single- or double-curvature under uniaxial or biaxial bending) is presented in a companion paper. The columns that can be analyzed with this method include those with solid and hollow rectangular, circular, oval, C-, T-, L-, or any arbitrary shape) cross sections and columns made of circular and rectangular steel tubes filled with HSC. In this paper, the validity of the proposed method is tested against experimental results from the technical literature that examined over seventy column specimens.En un artículo adjunto se presenta el método analítico para calcular las respuestas, a corto y largo plazo, de las columnas esbeltas de concreto en alta resistencia (HSC) y de los tubos rellenos de hormigón; con condiciones de apoyo generalizados, sometidos a cargas transversales de luz y a cargas axiales excéntricas en los extremos (causando curvatura simple o doble bajo flexión uniaxial o biaxial).Los tipos de columnas que pueden ser analizadas son: ovaladas, rectangulares, circulares, C, T, L o de cualquier sección transversal arbitraria, sólida o hueca, además, las que están hechas de tubos de acero circulares y rectangulares llenos de concreto en alta resistencia. En esta publicación se presenta la validez del método y los resultados obtenidos son comparados con otros, que han sido reportados por diferentes investigadores en la literatura técnica, con más de setenta muestras de columnas

Agent organisations: from independent agents to virtual organisations and societies of agents

Real world applications using agent-based solutions can include many agents that needs to communicate and interact with each other in order to meet their objectives. In organisations; Agent open multi-agent systems, problems can include not only the organisation of a large number of agents, but can also be heterogeneous and of unpredictable provenance or behavior. An overview of the alternatives for dealing with these problems is presented, highlighting the way they try to solve or mitigate them. This approach allows the development of complex systems in which there are agents that show very different behaviours and that are able to adapt to unforeseen changes in the environment. This makes it possible to simulate socio-technical or natural environments and observe their possible evolution without the ethical considerations involved in experimenting in real environments.This work has been developed as part of “Virtual-Ledgers-Tecnologías DLT/Blockchain y Cripto-IOT sobre organizaciones virtuales de agentes ligeros y su aplicación en la eficiencia en el transporte de última milla”, ID SA267P18, project financed by Junta Castilla y León, Consejería de Educación, and FEDER funds. It has been partially supported by the European Regional Development Fund (ERDF) through the Interreg Spain-Portugal V-A Program (POCTEP) under grant 0631_DIGITEC_3_E (Smart growth through the specialization of the cross-border business fabric in advanced digital technologies and blockchain.)

Stereoisomerization of α-hydroxy-β-sulfenyl-α,β-dimethyl naphthoquinones controlled by nonbonded sulfur–oxygen interactions

The anti α-hydroxy-β-sulfenyl-α,β-dimethyl naphthoquinones isomerize in basic media into syn/anti mixtures of isomers, giving the syn isomer as the major product. Conversely, anti α-hydroxy-β-alkoxy-α,β-dimethyl naphthoquinones isomerize to furnish the anti isomer as the major product. The crystal structure of syn α-hydroxy-β-phenylsulfenyl-α,β-dimethyl naphthoquinone has been determined. The X-ray and experimental work demonstrated that an attractive 1,4 intramolecular interaction of divalent sulfur with hydroxyl oxygen is the driving force for the aforementioned stereochemical preference