Institution
Polytechnic University of Catalonia
Education•Barcelona, Spain•
About: Polytechnic University of Catalonia is a education organization based out in Barcelona, Spain. It is known for research contribution in the topics: Finite element method & Population. The organization has 16006 authors who have published 45325 publications receiving 949306 citations. The organization is also known as: UPC - BarcelonaTECH & Technical University of Catalonia.
Topics: Finite element method, Population, Context (language use), Computer science, Nonlinear system
Papers published on a yearly basis
Papers
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25 Jan 2020
TL;DR: PASE+ is proposed, an improved version of PASE that better learns short- and long-term speech dynamics with an efficient combination of recurrent and convolutional networks and learns transferable representations suitable for highly mismatched acoustic conditions.
Abstract: Despite the growing interest in unsupervised learning, extracting meaningful knowledge from unlabelled audio remains an open challenge. To take a step in this direction, we recently proposed a problem-agnostic speech encoder (PASE), that combines a convolutional encoder followed by multiple neural networks, called workers, tasked to solve self-supervised problems (i.e., ones that do not require manual annotations as ground truth). PASE was shown to capture relevant speech information, including speaker voice-print and phonemes. This paper proposes PASE+, an improved version of PASE for robust speech recognition in noisy and reverberant environments. To this end, we employ an online speech distortion module, that contaminates the input signals with a variety of random disturbances. We then propose a revised encoder that better learns short- and long-term speech dynamics with an efficient combination of recurrent and convolutional networks. Finally, we refine the set of workers used in self-supervision to encourage better cooperation.Results on TIMIT, DIRHA and CHiME-5 show that PASE+ significantly outperforms both the previous version of PASE as well as common acoustic features. Interestingly, PASE+ learns transferable representations suitable for highly mismatched acoustic conditions.
237 citations
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TL;DR: A novel approach for ship detection is proposed based on the analysis of SAR images by means of the discrete wavelet transform, which takes advantage of the difference of statistical behavior among the ships and the surrounding sea, interpreting the information through the wavelet coefficients in order to provide a more reliable detection.
Abstract: Carrying out an effective control of fishing activities is essential to guarantee a sustainable exploitation of sea resources. Nevertheless, as the regulated areas are extended, they are difficult and time consuming to monitor by means of traditional reconnaissance methods such as planes and patrol vessels. On the contrary, satellite-based synthetic aperture radar (SAR) provides a powerful surveillance capability allowing the observation of broad expanses, independently from weather effects and from the day and night cycle. Unfortunately, the automatic interpretation of SAR images is often complicated, even though undetected targets are sometimes visible by eye. Attending to these particular circumstances, a novel approach for ship detection is proposed based on the analysis of SAR images by means of the discrete wavelet transform. The exposed method takes advantage of the difference of statistical behavior among the ships and the surrounding sea, interpreting the information through the wavelet coefficients in order to provide a more reliable detection. The analysis of the detection performance over both simulated and real images confirms the robustness of the proposed algorithm.
236 citations
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TL;DR: The results show that it would be very difficult to meet the EU limit values for PM10 established for 2010, and the main PM10 sources were mineral dust, emissions derived from power generation, vehicle exhausts, and marine aerosol.
236 citations
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TL;DR: In this article, Alonso et al. used oedometer tests on an artificially prepared bentonite-sand mixture (80% bentonite by dry mass) to identify the most important features controlling soil behaviour.
236 citations
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TL;DR: In this article, a series of optical spectroscopic and photometric observations of PSR J2215+5135, a "redback" binary MSP in a 4.14 hr orbit, and measure a drastic temperature contrast between the dark/cold (T N = 5660 K) and bright/hot (T D = 8080 K) sides of the companion star.
Abstract: New millisecond pulsars (MSPs) in compact binaries provide a good opportunity to search for the most massive neutron stars. Their main-sequence companion stars are often strongly irradiated by the pulsar, displacing the effective center of light from their barycenter and making mass measurements uncertain. We present a series of optical spectroscopic and photometric observations of PSR J2215+5135, a "redback" binary MSP in a 4.14 hr orbit, and measure a drastic temperature contrast between the dark/cold (T N = 5660 K) and bright/hot (T D = 8080 K) sides of the companion star. We find that the radial velocities depend systematically on the atmospheric absorption lines used to measure them. Namely, the semi-amplitude of the radial velocity curve (RVC) of J2215 measured with magnesium triplet lines is systematically higher than that measured with hydrogen Balmer lines, by 10%. We interpret this as a consequence of strong irradiation, whereby metallic lines dominate the dark side of the companion (which moves faster) and Balmer lines trace its bright (slower) side. Further, using a physical model of an irradiated star to fit simultaneously the two-species RVCs and the three-band light curves, we find a center-of-mass velocity of K 2 = 412.3 ± 5.0 km s−1 and an orbital inclination i = 639. Our model is able to reproduce the observed fluxes and velocities without invoking irradiation by an extended source. We measure masses of M 1 = 2.27 M ⊙ and M 2 = 0.33 M ⊙ for the neutron star and the companion star, respectively. If confirmed, such a massive pulsar would rule out some of the proposed equations of state for the neutron star interior.
235 citations
Authors
Showing all 16211 results
Name | H-index | Papers | Citations |
---|---|---|---|
Frede Blaabjerg | 147 | 2161 | 112017 |
Carlos M. Duarte | 132 | 1173 | 86672 |
Ian F. Akyildiz | 117 | 612 | 99653 |
Josep M. Guerrero | 110 | 1197 | 60890 |
David S. Wishart | 108 | 523 | 76652 |
O. C. Zienkiewicz | 107 | 455 | 71204 |
Maciej Lewenstein | 104 | 931 | 47362 |
Jordi Rello | 103 | 694 | 35994 |
Anil Kumar | 99 | 2124 | 64825 |
Surendra P. Shah | 99 | 710 | 32832 |
Liang Wang | 98 | 1718 | 45600 |
Aharon Gedanken | 96 | 861 | 38974 |
María Vallet-Regí | 95 | 711 | 41641 |
Bonaventura Clotet | 94 | 784 | 39004 |
Roberto Elosua | 90 | 481 | 54019 |