Les portes al riu

El projecte parteix d'un encàrrec per part de l'Ajuntament de Sallent de Llobregat, la millora de les lleres del riu al seu pas pel nucli urbà. Posterior a una anàlisi urbanístic de la zona determinem que el millor àmbit a on actuar és la Plaça 19 d'Abril i el seu entorn, ja que és un gran espai de relació riu-poble urbanitzat però que presenta grans dèficits a causa de l'ús que se li dóna, un aparcament informal. Aquest punt, a més, suposa una interrupció dels traçats de gran recorregut que creuen el municipi. El projecte, "Les portes al riu", mitjançant estratègies de deconstrucció i canvi d'us retornarà aquest espai al poble com una zona de rebuda al riu i el punt de connexió amb el parc fluvial. El projecte es divideix en tres actuacions, l'aparcament, la baixada al fluvial i el parc esportiu urbà. Actualment aquesta àmplia zona s'utilitza com a aparcament informal, envaint tot l'espai, la primera actuació serà posar ordre a aquest aparcament per tal d'alliberar altres zones de la plaça. Amb aquesta actuació també es crearan zones d'estada que valorin els elements patrimonials existents a l'àmbit. La segona actuació és la millora de la baixada al parc fluvial, l'àmbit natural més gran del municipi. Es fa una neteja i arranjament de la zona mantenint el caràcter rural del camí. L'última actuació a realitzar és un Parc esportiu urbà. A la zona superior de la plaça se situen 2 mòduls de patinatge amb un ús molt intensiu de patinadors. Un cop aquesta part de la plaça s'ha alliberat de vehicles es planteja construir un parc esportiu urbà, millorant les condicions dels patinadors alhora que la qualitat de la plaça. S'allibera l'espai per poder dur a terme activitats de poble sense que aquestes no entrin en conflicte amb els skaters

RDF-TR: Exploiting structural redundancies to boost RDF compression

The number and volume of semantic data have grown impressively over the last decade, promoting compression as an essential tool for RDF preservation, sharing and management. In contrast to universal compressors, RDF compression techniques are able to detect and exploit specific forms of redundancy in RDF data. Thus, state-of-the-art RDF compressors excel at exploiting syntactic and semantic redundancies, i.e., repetitions in the serialization format and information that can be inferred implicitly. However, little attention has been paid to the existence of structural patterns within the RDF dataset; i.e. structural redundancy. In this paper, we analyze structural regularities in real-world datasets, and show three schema-based sources of redundancies that underpin the schema-relaxed nature of RDF. Then, we propose RDF-Tr (RDF Triples Reorganizer), a preprocessing technique that discovers and removes this kind of redundancy before the RDF dataset is effectively compressed. In particular, RDF-Tr groups subjects that are described by the same predicates, and locally re-codes the objects related to these predicates. Finally, we integrate RDF-Tr with two RDF compressors, HDT and k2-triples. Our experiments show that using RDF-Tr with these compressors improves by up to 2.3 times their original effectiveness, outperforming the most prominent state-of-the-art techniques

Shift Selection Influence in Partial Cycle Spinning Denoising of Biomedical Signals

Denoising of biomedical signals using wavelet transform is a widely used technique. The use of undecimated wavelet transform (UWT) assures better denoising results but implies a higher complexity than discrete wavelet transform (DWT). Some implementation schemes have been proposed to perform UWT, one of them is Cycle Spinning (CS). CS is performed using the DWT of several circular shifted versions of the signal to analyse. The reduction of the number of shifted versions of the biomedical signal during denoising process used is addressed in the present work. This paper is about a variant of CS with a reduced number of shifts, called Partial Cycle Spinning (PCS), applied to ultrasonic trace denoising. The influence of the choice of PCS shifts in the denoised registers quality is studied. Several shifts selection rules are proposed, compared and evaluated. Denoising results over a set of ultrasonic registers are provided for PCS with different shift selection rules, CS and DWT. The work shows that PCS with the appropriate choice of shifts could be the best option to denoise biomedical ultrasonic traces. (C) 2015 Elsevier Ltd. All rights reserved.This work was partially supported by Spanish Government MEC Project TIN2013-47272-C2-1-R.Rodríguez-Hernández, MA. (2016). Shift Selection Influence in Partial Cycle Spinning Denoising of Biomedical Signals. Biomedical Signal Processing and Control. 26:64-68. https://doi.org/10.1016/j.bspc.2015.12.002S64682

Reduced Cycle Spinning Method for the Undecimated Wavelet Transform

[EN] The Undecimated Wavelet Transform is commonly used for signal processing due to its advantages over other wavelet techniques, but it is limited for some applications because of its computational cost. One of the methods utilized for the implementation of the Undecimated Wavelet Transform is the one known as Cycle Spinning. This paper introduces an alternative Cycle Spinning implementation method that divides the computational cost by a factor close to 2. This work develops the mathematical background of the proposed method, shows the block diagrams for its implementation and validates the method by applying it to the denoising of ultrasonic signals. The evaluation of the denoising results shows that the new method produces similar denoising qualities than other Cycle Spinning implementations, with a reduced computational cost.This research was funded by grants number PGC2018-09415-B-I00 (MCIU/AEI/FEDER, UE) and TEC2015-71932-REDT.Rodríguez-Hernández, MA. (2019). Reduced Cycle Spinning Method for the Undecimated Wavelet Transform. Sensors. 19(12):1-16. https://doi.org/10.3390/s19122777S1161912Signal Processing Fourier and Wavelet Representationshttp://www.fourierandwavelets.org/SPFWR_a3.1_2012.pdfZhao, H., Zuo, S., Hou, M., Liu, W., Yu, L., Yang, X., & Deng, W. (2018). A Novel Adaptive Signal Processing Method Based on Enhanced Empirical Wavelet Transform Technology. Sensors, 18(10), 3323. doi:10.3390/s18103323Gradolewski, D., Magenes, G., Johansson, S., & Kulesza, W. (2019). A Wavelet Transform-Based Neural Network Denoising Algorithm for Mobile Phonocardiography. Sensors, 19(4), 957. doi:10.3390/s19040957Shikhsarmast, F., Lyu, T., Liang, X., Zhang, H., & Gulliver, T. (2018). Random-Noise Denoising and Clutter Elimination of Human Respiration Movements Based on an Improved Time Window Selection Algorithm Using Wavelet Transform. Sensors, 19(1), 95. doi:10.3390/s19010095Shensa, M. J. (1992). The discrete wavelet transform: wedding the a trous and Mallat algorithms. IEEE Transactions on Signal Processing, 40(10), 2464-2482. doi:10.1109/78.157290Li, M., & Ghosal, S. (2015). Fast Translation Invariant Multiscale Image Denoising. IEEE Transactions on Image Processing, 24(12), 4876-4887. doi:10.1109/tip.2015.2470601Hazarika, D., Nath, V. K., & Bhuyan, M. (2016). SAR Image Despeckling Based on a Mixture of Gaussian Distributions with Local Parameters and Multiscale Edge Detection in Lapped Transform Domain. Sensing and Imaging, 17(1). doi:10.1007/s11220-016-0141-8Sakhaee, E., & Entezari, A. (2017). Joint Inverse Problems for Signal Reconstruction via Dictionary Splitting. IEEE Signal Processing Letters, 24(8), 1203-1207. doi:10.1109/lsp.2017.2701815Ong, F., Uecker, M., Tariq, U., Hsiao, A., Alley, M. T., Vasanawala, S. S., & Lustig, M. (2014). Robust 4D flow denoising using divergence-free wavelet transform. Magnetic Resonance in Medicine, 73(2), 828-842. doi:10.1002/mrm.25176Rehman, N. ur, Abbas, S. Z., Asif, A., Javed, A., Naveed, K., & Mandic, D. P. (2017). Translation invariant multi-scale signal denoising based on goodness-of-fit tests. Signal Processing, 131, 220-234. doi:10.1016/j.sigpro.2016.08.019Mota, H. de O., Vasconcelos, F. H., & de Castro, C. L. (2016). A comparison of cycle spinning versus stationary wavelet transform for the extraction of features of partial discharge signals. IEEE Transactions on Dielectrics and Electrical Insulation, 23(2), 1106-1118. doi:10.1109/tdei.2015.005300Li, D., Wang, Y., Lin, J., Yu, S., & Ji, Y. (2016). Electromagnetic noise reduction in grounded electrical‐source airborne transient electromagnetic signal using a stationarywavelet‐based denoising algorithm. Near Surface Geophysics, 15(2), 163-173. doi:10.3997/1873-0604.2017003San Emeterio, J. L., & Rodriguez-Hernandez, M. A. (2014). Wavelet Cycle Spinning Denoising of NDE Ultrasonic Signals Using a Random Selection of Shifts. Journal of Nondestructive Evaluation, 34(1). doi:10.1007/s10921-014-0270-8Rodriguez-Hernandez, M. A., & Emeterio, J. L. S. (2015). Noise reduction using wavelet cycle spinning: analysis of useful periodicities in the z-transform domain. Signal, Image and Video Processing, 10(3), 519-526. doi:10.1007/s11760-015-0762-8Rodriguez-Hernandez, M. A. (2016). Shift selection influence in partial cycle spinning denoising of biomedical signals. Biomedical Signal Processing and Control, 26, 64-68. doi:10.1016/j.bspc.2015.12.002Beylkin, G., Coifman, R., & Rokhlin, V. (1991). Fast wavelet transforms and numerical algorithms I. Communications on Pure and Applied Mathematics, 44(2), 141-183. doi:10.1002/cpa.3160440202Beylkin, G. (1992). On the Representation of Operators in Bases of Compactly Supported Wavelets. SIAM Journal on Numerical Analysis, 29(6), 1716-1740. doi:10.1137/0729097Donoho, D. L., & Johnstone, I. M. (1994). Ideal spatial adaptation by wavelet shrinkage. Biometrika, 81(3), 425-455. doi:10.1093/biomet/81.3.425Donoho, D. L., & Johnstone, I. M. (1995). Adapting to Unknown Smoothness via Wavelet Shrinkage. Journal of the American Statistical Association, 90(432), 1200-1224. doi:10.1080/01621459.1995.10476626Johnstone, I. M., & Silverman, B. W. (1997). Wavelet Threshold Estimators for Data with Correlated Noise. Journal of the Royal Statistical Society: Series B (Statistical Methodology), 59(2), 319-351. doi:10.1111/1467-9868.00071Pardo, E., San Emeterio, J. L., Rodriguez, M. A., & Ramos, A. (2006). Noise reduction in ultrasonic NDT using undecimated wavelet transforms. Ultrasonics, 44, e1063-e1067. doi:10.1016/j.ultras.2006.05.101Donoho, D. L. (1995). De-noising by soft-thresholding. IEEE Transactions on Information Theory, 41(3), 613-627. doi:10.1109/18.382009Lázaro, J. C., San Emeterio, J. L., Ramos, A., & Fernández-Marrón, J. L. (2002). Influence of thresholding procedures in ultrasonic grain noise reduction using wavelets. Ultrasonics, 40(1-8), 263-267. doi:10.1016/s0041-624x(02)00149-xKarpur, P., Shankar, P. M., Rose, J. L., & Newhouse, V. L. (1987). Split spectrum processing: optimizing the processing parameters using minimization. Ultrasonics, 25(4), 204-208. doi:10.1016/0041-624x(87)90034-5Pardo, E., Emeterio, S. J. L., Rodriguez, M. A., & Ramos, A. (2008). Shift Invariant Wavelet Denoising of Ultrasonic Traces. Acta Acustica united with Acustica, 94(5), 685-693. doi:10.3813/aaa.91808

Higgs →\rightarrow μτ\mu\tau as an indication for S4S_4 flavor symmetry

Lepton flavor violating Higgs decays can arise in flavor symmetry models where the Higgs sector is responsible for both the electroweak and the flavor symmetry breaking. Here we advocate an $S_4$ three-Higgs-doublet model where tightly constrained flavor changing neutral currents are suppressed by a remnant $Z_3$ symmetry. A small breaking of this $Z_3$ symmetry can explain the $2.4\,\sigma$ excess of Higgs decay final states with a $\mu \tau$ topology reported recently by CMS if the new neutral scalars are light. The model also predicts sizable rates for lepton flavor violating Higgs decays in the $e\tau$ and $e \mu$ channels because of the unifying $S_4$ flavor symmetry.Comment: 15+9 pages, 7 figures, updated for publication in PR

AERODYNAMICS PERFORMANCES IN SPORTS

Aerodynamic forces are important in many racing sports and all those which use projectiles or any kind of ball. For all of them, the wind tunnel becomes one of the most efficient tools to improve the athlete performances and to coach as well. Coaching demands a lot of time wind tunnel occupancy, so its operating cost is very relevant. Advantages of specifically developed wind tunnels and possibilities of tests are discussed