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Now showing items 1 - 16 of 136

  • Majority Logical Function Using a pi’npin a-SiC:H Structure1

    Silva, V.   Barata, M.   Louro, P.   Vieira, M.A.   Vieira, M.  

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  • Logic functions based on optical bias controlled SiC tandem devices

    Silva, V.   Vieira, M. A.   Vieira, M.   Louro, P.   Fantoni, A.   Barata, M.  

    The purpose of this paper is the design of an optoelectronic circuit based on a-SiC technology, able to act simultaneously as a 4-bit binary encoder or a binary decoder in a 4-to-16 line configurations and show multiplexer-based logical functions. The device consists of a p-i'(a-SiC:H)-n/p-i(a-Si:H)-n multilayered structure produced by PECVD. To analyze it under information-modulated wave (color channels) and uniform irradiation (background) four monochromatic pulsed lights (input channels): red, green, blue and violet shine on the device. Steady state optical bias was superimposed separately from the front and the back sides, and the generated photocurrent was measured. Results show that the devices, under appropriate optical bias, act as reconfigurable active filters that allow optical switching and optoelectronic logic functions development providing the possibility for selective removal of useless wavelengths. The logic functions needed to construct any other complex logic functions are the NOT, and both or either an AND or an OR. Any other complex logic function that might be found can also be used as building blocks to achieve the functions needed for the retrieval of channels within the WDM communication link. (C) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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  • AND, OR, NOT Logical Functions in a SiC Tandem Device

    Silva, V.   Vieira, M.A.   Louro, P.   Barata, M.   Vieira, M.  

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  • Error rate analysis of M-PSK with magnitude modulation envelope control

    Silva, V.   Tomlinson, M.   Dinis, R.   Cercas, F.   Gomes, M.  

    Magnitude modulation (MM) envelope control is an efficient way of reducing the peak-to-average power ratio (PAPR) of single-carrier (SC) signals and improves an SC system's overall power efficiency. However, MM techniques reduce the PAPR at the cost of introducing distortion, highlighting a need to characterise the symbol error rate (SER) performance loss due to MM. This reported work focuses on the M-PSK case. An exact probability density function (PDF) based on the generalised extreme value distribution is proposed to model the statistical distribution of MM factors generated by MM techniques applied to SC constant amplitude constellations. By considering MM distortion as a form of fading, it is shown that this PDF may be used to derive an accurate union bound of the SER of M-PSK transmission on the additive white Gaussian channel channel when using MM envelope control.
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  • Lopes Gomes Da Silva v. Portugal

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  • Increased sensitivity in a-SiC pinpin multilayers in the VIS-NIR range under UV light

    Silva, V.   Rodrigues, I.   Vieira, M. A   Louro, P.   Vieira, M.  

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  • Prediction of Single Salt Rejection in Nanofiltration Membranes

    Silva, V.   Montalvillo, M.   Carmona, J.   Palacio, L.   Hernández, A.   Prádanos, P.  

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  • Posters * Demography, Epidemiology, Registries, and Health Economy

    Silva, V.   Pita Barros, P.   Lourenco, O.   Batel Marques, F.   Martinez-Salazar, J.   Palumbo, A.   De La Fuente, P.   Rodriguez, M.   Sanchez, F.   Lizan, C.   Marqueta, J.   Espallardo, O.   Lizan, L.   Polanco, C.   Paz, S.   Haagen, E. C.   Nelen, W. L. D. M.   Hermens, R. P. M. G.   Adang, E. M.   Grol, R. P. T. M.   Kremer, J. A. M.   Pinborg, A.   Hougaard, C. O.   Nyboe Andersen, A.   Kragh Andersen, P.   Boivin, J.   Schmidt, L.   Moolenaar, L.   Broekmans, F. B.   van de Veen, F.   Fauser, B. C. J. M.   Hompes, P.   Mol, B. W.   Porcu - Buisson, G.   Lehert, P.   Chabert - Orsini, V.   Giorgetti, C.   Shirkavand, A.   Sedigh Sarvestani, R.   Ezabadi, Z.   Omani Samani, R.   Silva Carvalho, J. L.   Santos, A.   Tabuas, I.   Braga, D. P. A. F.   Setti, A. S.   Figueira, R. C. S.   Queiroz, P.   Iaconelli, A.   Borges, E.   Fuldeore, M.   Wu, N.   Boulanger, L.   Chwalisz, K.   Marx, S.   Scaravelli, G.   De luca, R.   D\"Aloja, P.   Vigiliano, V.   Mayorga, J. M.   Bolli, S.   Spoletini, R.   Fiaccavento, S.   Monzo, A.   Flores, R.   Aniorte, S.   Rubio, J. M.   Peinado, I.   Pellicer, A.   Woodward, B. J.   Sohan, K.   Dahl, E.   Ziegler, A.   Horlbeck, S.   Strowitzki, T.   Eggert-Kruse, W.   Padhy, N.   Mahla, A.   Balasubramanyam, S.   Varma, T. R.   Yellamareddygari, S.   Willett, M. J.   Batra, S.   Farquhar, C.   Wang, Y. A.   Sullivan, A. E.  

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  • Extending displacement-based earthquake loss assessment (DBELA) for the computation of fragility curves

    Silva, V.   Crowley, H.   Pinho, R.   Varum, H.  

    This paper presents a new procedure to derive fragility functions for populations of buildings that relies on the displacement-based earthquake loss assessment (DBELA) methodology. The recent developments in this methodology are also presented herein, such as the development of new formulae for the calculation of the yield period or the consideration of infilled frame structures. In the fragility method proposed herein, thousands of synthetic buildings have been produced considering probabilistic distributions describing the variability in their geometrical and material properties. Then, their nonlinear capacity has been estimated using the DBELA method and their performance against a large set of ground motion records has been calculated. Global limit states are used to estimate the distribution of buildings in each damage state for different levels of ground motion, and a regression algorithm is applied to derive fragility functions for each limit state. The proposed methodology is demonstrated for the case of ductile and non-ductile Turkish reinforced concrete buildings with and without masonry infill walls, and compared with results obtained using nonlinear dynamic procedures and with the results from previous studies.
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  • Case of Matos e Silva, Lda. and others v. Portugal

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  • Quadtree based block merging algorithm for subband coding

    Silva, V.   de Sa, L.  

    In this paper an efficient video coding algorithm is described. It is based on a new quadtree block merging algorithm and wavelet decomposition of video signals using orthonormal and biorthogonal filter banks. The merging algorithm represents the motion compensated predicted images in a small set of rectangular regions in order to improve the coding efficiency and to minimize the border effects associated with the wavelet transform. Results of coding simulations using 8times8 and 16times16 blocks are presented. Also, subjects such as, choice of the optimal filter bank, boundary effects, quantization of the wavelet coefficients and filtering the prediction error by wavelet decomposition will be discussed
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  • Salgueiro Da Silva Mouta v. Portugal

    Difference in treatment in awarding parental responsibility dictated by factors related to sexual orientation of one parent was not permissible under the Convention.
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  • Salgueiro Da Silva Mouta v. Portugal

    Difference in treatment in awarding parental responsibility dictated by factors related to sexual orientation of one parent was not permissible under the Convention.
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  • Analytical optimization of CQF filter banks

    Silva, V.   de Sa, L.  

    The optimization of subband filter banks for signal and image coding is normally dealt with by numerical means. It is shown that this optimization can be done analytically in the case of the prototype four-tap causal conjugate quadrature filter (CQF). The coding gain and aliasing energy are considered in the optimization. Using parametrizations of the prototype filter coefficients, it was found that the optimal filter is the regular Daubechies D 2 wavelet filter
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  • General method for perfect reconstruction subband processing of finite length signals using linear extensions

    Silva, V.   De Sa, L.  

    A general approach to the nonexpansive M band decomposition of finite length signals is presented. The technique is based on linear signal extensions and can be applied to all types of linear- and nonlinear phase M-band perfect-reconstruction filter banks. The signal expansion is described by a linear transformation on the input signal, and the extended subband samples can be easily found using simple matrix computations
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  • Zirconium Oxide Modified Sulfonated Poly (Ether Ether Ketone) Membranes for Direct Methanol Fuel Cell Applications

    Silva, V.   Ruffmann, B.   Silva, H.   Mendes, A.   Madeira, M.   Nunes, S.  

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