Recent Submissions

  • Correlation between discharge timings of pairs of motor units reveals the presence but not the proportion of common synaptic input to motor neurons 

    Rodríguez Falces, Javier Upna; Negro, Francesco; Farina, Dario (American Physiological Society, 2017)   Artículo / Artikulua  OpenAccess
    We investigated whether correlation measures derived from pairs of motor unit (MU) spike trains are reliable indicators of the degree of common synaptic input to motor neurons. Several 50-s isometric contractions of the ...
  • Low complexity energy management strategy for grid profile smoothing of a residential grid-connected microgrid using generation and demand forecasting 

    Arcos Avilés, Diego; Pascual Miqueleiz, Julio María Upna; Guinjoan Gispert, Francesc; Marroyo Palomo, Luis Upna; Sanchís Gúrpide, Pablo Upna (Elsevier, 2017)   Artículo / Artikulua  OpenAccess
    This paper presents the design of an energy management strategy based on a low complexity Fuzzy Logic Control (FLC) for grid power profile smoothing of a residential grid-connected microgrid including Renewable Energy ...
  • Motor unit profile: a new way to describe the scanning-EMG potential 

    Corera Orzanco, Íñigo; Malanda Trigueros, Armando Upna; Rodríguez Falces, Javier Upna; Porta Cuéllar, Sonia Upna; Navallas Irujo, Javier Upna (Elsevier, 2017)   Artículo / Artikulua  OpenAccess
    The motor unit profile, a representation of the trajectories of positive and negative turns of a scanning-EMG signal, is a new way to characterize the motor unit potential. Such characterization allows quantification of ...
  • Continuous liquid-level sensor based on a long-period grating and microwave photonics filtering techniques 

    Ricchiuti, Amelia L.; Barrera, D.; Urrutia Azcona, Aitor Upna; Goicoechea Fernández, Javier Upna; Arregui San Martín, Francisco Javier Upna (IEEE, 2016)   Artículo / Artikulua  OpenAccess
    A fiber optic liquid-level sensor based on a long period grating (LPG) is proposed and experimentally validated. The principle of operation is based on a technique used to analyze microwave photonics filters. A 4-cm-long ...
  • Simultaneous measurement of humidity and temperature based on a partially coated optical fiber long period grating 

    Urrutia Azcona, Aitor Upna; Goicoechea Fernández, Javier Upna; Ricchiuti, Amelia L.; Barrera, D.; Arregui San Martín, Francisco Javier Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
    A humidity and temperature optical fiber sensor based on a long-period grating (LPG), which can provide simultaneous response to both magnitudes, is proposed and demonstrated via experiments. Previously, the LPG was fully ...
  • A comparative study in the sensitivity of optical fiber refractometers based on the incorporation of gold nanoparticles into layer-by-layer films 

    Rivero Fuente, Pedro Upna; Hernáez Sáenz de Zaitigui, Miguel Upna; Goicoechea Fernández, Javier Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (Exeley, 2015)   Artículo / Artikulua  OpenAccess
    In this work, optical fiber refractometers based on the successive incorporation of gold nanoparticles have been fabricated by means of the Layer-by-Layer Embedding (LbL-E) deposition technique. This enables the apparition ...
  • Ultrafast electrooptic dual-comb interferometry 

    Durán, Vicente; Tainta Ausejo, Santiago Upna; Torres Company, Víctor (Optical Society of America, 2015)   Artículo / Artikulua  OpenAccess
    Dual-comb interferometry is a particularly compelling technique that relies on the phase coherence of two laser frequency combs for measuring broadband complex spectra. This method is rapidly advancing the field of optical ...
  • Experimental demonstration of a millimeter-wave metallic ENZ lens based on the energy squeezing principle 

    Torres Landívar, Víctor Upna; Orazbayev, Bakhtiyar Upna; Pacheco Peña, Víctor Upna; Teniente Vallinas, Jorge Upna; Beruete Díaz, Miguel Upna; Navarro Cía, Miguel Upna; Sorolla Ayza, Mario Upna (IEEE, 2015)   Artículo / Artikulua  OpenAccess
    The performance of an epsilon-near zero (ENZ) plano-concave lens is experimentally demonstrated and verified at the D-band of the millimeter-waves. The lens is comprised of an array of narrow metallic waveguides near cut-off ...
  • Terahertz carpet cloak based on a ring resonator metasurface 

    Orazbayev, Bakhtiyar Upna; Mohammadi Estakhri, Nasim; Beruete Díaz, Miguel Upna; Alù, Andrea (American Physical Society, 2015)   Artículo / Artikulua  OpenAccess
    In this work we present the concept and design of an ultrathin (λ/22) terahertz (THz) unidirectional carpet cloak based on the local phase compensation approach enabled by gradient metasurfaces. A triangular surface bump ...
  • Band-pass filter-like antenna validation in an ultra-wideband in-car wireless channel 

    García Zuazola, Ignacio Julio; Azpilicueta Fernández de las Heras, Leyre Upna; Sharma, Ashwani; Landaluce, Hugo; Falcone Lanas, Francisco Javier Upna (Institution of Engineering and Technology (IET), 2015)   Artículo / Artikulua  OpenAccess
    Ultra-wideband (UWB) is a very attractive technology for innovative in-car wireless communications requiring high data rates. A designated antenna, which presents a reflection coefficient (S11) matched band comparable to ...
  • Performance comparison and design guidelines for Type II and Type III PLLs 

    Ugarte Gil, Mikel Upna; Carlosena García, Alfonso Upna (Birkhauser, 2015)   Artículo / Artikulua  OpenAccess
    The advantages provided by Type III PLLs are poorly known, since these devices are very often considered unstable and difficult, or even impossible, to design. In this paper, a performance comparison between Type II and ...
  • Novel sensor design using photonic crystal fibres for monitoring the onset of corrosion in reinforced concrete structures 

    McCague, Colum; Fabian, Matthias; Karimi, Mohammad; Bravo Acha, Mikel Upna; Jaroszewicz, Leszek R. (IEEE, 2014)   Artículo / Artikulua  OpenAccess
    In this paper, a novel sensing technique has been designed and investigated for the direct, in situ detection of steel corrosion distributed in reinforced concrete structures. At present, structural health monitoring in ...
  • Compact dual-band terahertz quarter-wave plate metasurface 

    Torres Landívar, Víctor Upna; Etayo Salinas, David Upna; Ortuño Molinero, Rubén Upna; Navarro Cía, Miguel Upna; Beruete Díaz, Miguel Upna (IEEE, 2014)   Artículo / Artikulua  OpenAccess
    A dual-band quarter-wave plate based on a modified extraordinary transmission hole array is numerically analyzed and experimentally demonstrated at terahertz frequencies. To control independently orthogonal polarizations, ...
  • Mapping smooth profile H-plane rectangular waveguide structures to substrate integrated waveguide technology 

    Díaz Caballero, E.; Urrea Micó, Verónica; Chudzik, Magdalena Upna; Arregui Padilla, Iván Upna; Arnedo Gil, Israel Upna (Institution of Engineering and Technology, 2014)   Artículo / Artikulua  OpenAccess
    The guidelines for mapping rectangular waveguide structures to substrate integrated waveguide (SIW) technology are well understood for structures with straight walls. However, the mapping of a smooth profile structure from ...
  • Growth in the number of references in engineering journal papers during the 1972-2013 period 

    Úcar Marqués, Iñaki; López Fernandino, Felipe; Rodríguez Ulibarri, Pablo Upna; Sesma Sánchez, Laura Upna; Urrea Micó, Verónica; Sevilla Moróder, Joaquín Upna (Springer, 2014)   Artículo / Artikulua  OpenAccess
    The number of references per paper, perhaps the best single index of a journal’s scholarliness, has been studied in different disciplines and periods. In this paper we present a four decade study of eight engineering ...
  • Compact groove diamond antenna in gap waveguide technology with broadband circular polarization at millimeter waves 

    Pérez, Dayan; Torres-García, Alicia Upna; Ederra Urzainqui, Íñigo Upna; Beruete Díaz, Miguel Upna (IEEE, 2020)   Artículo / Artikulua
    In this paper, three compact antennas using the Ridge Gap Waveguide (RGW) technology working in the millimeter-wave band (60 GHz), with a high-purity and broadband circular polarization (CP) are numerically and experimentally ...
  • All-fiber lasers through photonic crystal fibers 

    Rodrigues Pinto, Ana Margarida Upna; López-Amo Sáinz, Manuel Upna (Science Wise Publishing & De Gruyter, 2013)   Artículo / Artikulua  OpenAccess
    A review on all-fiber lasers based on photonic crystal fibers is presented. Photonic crystal fibers present improved features beyond what conventional optical fibers can offer. Due to their geometric versatility, photonic ...
  • Comparative study of ring and random cavities for fiber lasers 

    Fernández Vallejo, Montserrat Upna; Rota Rodrigo, Sergio Upna; López-Amo Sáinz, Manuel Upna (Optical Society of America, 2014)   Artículo / Artikulua  OpenAccess
    An experimental comparison of three fiber laser structures with the same Raman gain medium is presented in order to establish the main pros and cons of each basic scheme. The first fiber laser is based on a hybrid ring–random ...
  • Internal modulation of a Random fiber laser 

    Bravo Acha, Mikel Upna; Fernández Vallejo, Montserrat Upna; López-Amo Sáinz, Manuel Upna (Optical Society of America, 2013)   Artículo / Artikulua  OpenAccess
    A characterization of a modulated random mirror laser has been experimentally carried out. Unlike conventional internally modulated fiber lasers, no distortion of the modulating frequency or self-mode-locking effects were ...
  • Experimental evidence of coherence resonance in a time-delayed bistable system 

    Arizaleta Arteaga, Mikel Upna; Valencia, Miguel; Sciamanna, Marc; Thienpont, Hugo; López-Amo Sáinz, Manuel Upna; Panajotov, Krassimir (APS Physics, 2007)   Artículo / Artikulua  OpenAccess
    We report on the experimental observation of coherence resonance in a bistable system with delay. Our system consists of a vertical-cavity surface-emitting laser subject to time-delayed optical feedback simultaneously from ...

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