Exploració per tema "Time-frequency analysis"

Ara es mostren els items 1-17 de 17

    • A comparison of several recent methods of fundamental frequency and voicing decision estimation 

      Rodríguez Fonollosa, José Adrián (H. TIMOTHY BRUMMELL, WILLIAM IDSARDI CITATION DELAWARE, NEW CASTLE, DELAWARE, 1996)
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      The authors are interested in the comparison of several kinds of methods for fundamental frequency estimation and GCI (glottal closure instant) detection. These methods operate in various domains (time-, frequency- or joint ...

    • A knowledge-based approach to automatic detection of equipment alarm sounds in a neonatal intensive care unit environment 

      Raboshchuk, Ganna; Nadeu Camprubí, Climent; Jancovic, Peter; Peiró Lilja, Alexandre Cristian; Kokuer, Munevver; Muñoz Mahamud, Blanca; Riverola de Veciana, Ana (2017-12-21)
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      A large number of alarm sounds triggered by biomedical equipment occur frequently in the noisy environment of a neonatal intensive care unit (NICU) and play a key role in providing healthcare. In this paper, our work on ...

    • A new positive time-frequency distribution 

      Rodríguez Fonollosa, Javier; Nikias, C L (1994)
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      This article studies the formulation of new members of the Cohen-Posch (1985) class of positive time-frequency energy distributions. Members of this class are always positive functionals and satisfy the marginal constraints. ...

    • A pragmatic gaze on stochastic resonance based variability tolerant memristance 

      Ntinas, Vasileios; Rubio Sola, Jose Antonio; Sirakoulis, Georgios Ch.; Cotofana, Sorin (Institute of Electrical and Electronics Engineers (IEEE), 2019)
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      Stochastic Resonance (SR) is a nonlinear system specific phenomenon, which was demonstrated to lead to system unexpected (counter-intuitive) performance improvements under certain noise conditions. Memristor, on the other ...

    • Analysis and reduction of the distortions induced by time-domain filtering techniques in network analyzers 

      Porrata-Dòria i Yagüe, Ramir de; Broquetas Ibars, Antoni; Martínez, Luís Fernando (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1998-08-31)
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      The removal of isolation errors plays an essential role in the calibration process of radar scattering measurements. One of the most common techniques used for that purpose is time-domain filtering, also known as gating. ...

    • Analysis of tracheal and pulmonary continuous adventitious respiratory sounds in asthma 

      Lozano García, Manuel; Davidson, Clare M.; Jané Campos, Raimon (Institute of Electrical and Electronics Engineers (IEEE), 2019)
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      Continuous adventitious sounds (CAS) are commonly observed in obstructive pulmonary diseases and are of great clinical interest. However, their evaluation is generally subjective. We have previously developed an automatic ...

    • Auditory and nociceptive stimuli responses in the electro–encephalogram : a non-linear measures and time-frequency representation based analysis 

      Melia, Umberto Sergio Pio; Vallverdú Ferrer, Montserrat; Clarià Sancho, Francesc; Valls-Solé, Josep; Caminal Magrans, Pere (2014)
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      Accés restringit per política de l'editorial
      Introduction: This article is part of the Focus Theme of Methods of Information in Medicine on “Biosignal Interpretation: Advanced Methods for Neural Signals and Images“. Objectives: An efficient way to investigate the ...

    • Automatic vessel monitoring with single and multidimensional SAR images in the wavelet domain 

      Tello Alonso, Mª Victoria; López Martínez, Carlos; Mallorquí Franquet, Jordi Joan (ELSEVIER SCIENCE BV, 2006-12-31)
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      Spaceborne Synthetic Aperture Radar (SAR) techniques constitute an extremely promising alternative compared to traditional surveillance methods thanks to the all-weather and day-and-night capabilities of Radar linked with ...

    • Cooperative dual Leo satellite transmission in multi-user OTFS systems 

      Caus López, Màrius; Shaat, Musbah; Pérez Neira, Ana Isabel; Schellmann, Malte; Cao, Hanwen (Institute of Electrical and Electronics Engineers (IEEE), 2023)
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      This paper explores multi-satellite transmission schemes. The focus is on the multi-user downlink scenario, where two low Earth orbit satellites transmit data cooperatively, which are then combined at each of the ground ...

    • Degradation detection and severity estimation by exploiting an optical time and frequency digital twin 

      Devigili, Mariano; Ruiz Ramírez, Marc; Barzegar, Sima; Costa, Nelson; Napoli, Antonio; Pedro, João; Velasco Esteban, Luis Domingo (Institute of Electrical and Electronics Engineers (IEEE), 2023)
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      We exploit the intrinsic advantages of a time and frequency domain digital twin to detect degradations and to estimate their severity. Noticeable performance shown for filter failures confirms the usefulness of this approach.

    • EMI model of an AC/AC power converter 

      Espina Masramon, Jorge; Balcells Sendra, Josep; Arias Pujol, Antoni; Ortega García, Carlos; Berbel Artal, Néstor (2010)
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      This paper deals with the validation of an EMI model to predict electromagnetic interferences (EMI) produced by power converters. A direct AC to AC matrix converter (MC) has been selected as experimental setup for the ...

    • Low entropy map of brain oscillatory activity identifies spatially localized events: A new method for automated epilepsy focus prediction 

      Principe, Alessandro; Tauste Campo, Adrián Francisco; Vila Vidal, Manel; Rocamora, Rodrigo; Deco, Gustavo; Pérez Enríquez, Carmen (2020-03)
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      The spatial mapping of localized events in brain activity critically depends on the correct identification of the pattern signatures associated with those events. For instance, in the context of epilepsy research, a number ...

    • Positive time-frequency distributions based on joint marginal constraints 

      Rodríguez Fonollosa, Javier (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1996-08-01)
      Article
      Accés obert
      This correspondence studies the formulation of members of the Cohen-Posch class of positive time-frequency energy distributions. Minimization of cross-entropy measures with respect to different priors and the case of ...

    • Relationship between sleep stages and HRV response in obstructive sleep apnea patients 

      Romero Pérez, Daniel; Jané Campos, Raimon (Institute of Electrical and Electronics Engineers (IEEE), 2021)
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      Patients suffering from obstructive sleep apnea (OSA) usually present an increased sympathetic activity caused by the intermittent hypoxia effect on autonomic control. This study evaluated the relationship between sleep ...

    • Reliability oriented OTFS-based LEO satellites joint transmission scheme 

      Caus López, Màrius; Shaat, Musbah; Pérez Neira, Ana Isabel; Schellmann, Malte; Ca, Hanwen (Institute of Electrical and Electronics Engineers (IEEE), 2022)
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      This paper investigates a dual satellite transmission scheme with coherent reception. The receiver has a single synchronization circuit and is locked to only one of the satellites. Beam-centric pre-compensation techniques ...

    • Sex differences in autonomic response to exercise testing in patients with Brugada syndrome 

      Calvo González, Mireia; Le Rolle, Virginie; Romero Pérez, Daniel; Béhar, Nathalie; Gomis Román, Pedro; Mabo, Philippe; Hernández, Alfredo I. (Springer, 2018-07-12)
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      Ventricular arrhythmias in Brugada syndrome (BS) typically occur at rest and especially during sleep, suggesting that changes in the autonomic modulation may play an important role in arrhythmogenesis. The autonomic response ...

    • Wigner higher-order spectra: definition, properties, computation and application to transient signal analysis 

      Rodríguez Fonollosa, Javier; Nikias, Chrysostomos L. (IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 1993-01-31)
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      The Wigner higher order moment spectra (WHOS) are defined as extensions of the Wigner-Ville distribution (WD) to higher order moment spectra domains. A general class of time-frequency higher order moment spectra is also ...