• Application of two different methods for extending lattice-valued restricted equivalence functions used for constructing similarity measures on L-fuzzy sets 

      Palmeira, Eduardo S.; Bedregal, Benjamin; Bustince Sola, Humberto Upna; Paternain Dallo, Daniel Upna; Miguel Turullols, Laura de Upna (Elsevier, 2018)   Artículo / Artikulua
      Based on previous investigations, we have proposed two different methods to extend lattice-valued fuzzy connectives (t-norms, t-conorms, negations and implications) and other related operators, considering a generalized ...
    • Convolution lattices 

      Miguel Turullols, Laura de Upna; Bustince Sola, Humberto Upna; De Baets, Bernard (Elsevier, 2018)   Artículo / Artikulua
      We propose two convolution operations on the set of functions between two bounded lattices and investigate the algebraic structure they constitute, in particular the lattice laws they satisfy. Each of these laws requires ...
    • Multivalued contexts associated with criteria 

      Alcalde, Cristina; Burusco Juandeaburre, Ana Upna (Taylor & Francis, 2018)   Artículo / Artikulua
      We are interested in the study of L-fuzzy contexts taking into account different criteria. These contexts arise when we want to analyze the relationship between objects and attributes from different points of view. ...
    • Ku band low profile asymmetric Bull’s-Eye antenna with reduced side lobes and monopole feeding 

      Beaskoetxea Gartzia, Unai Upna; Torres García, Alicia E. Upna; Beruete Díaz, Miguel Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      In this paper, a linearly polarized low profile and asymmetric Bull’s-Eye leaky wave antenna fed by a monopole operating at 13 GHz is presented. Broadside radiation from the monopole is achieved by surrounding it with an ...
    • Extraordinary THz transmission with a small beam spot: the leaky wave mechanism 

      Navarro Cía, Miguel Upna; Pacheco Peña, Víctor Upna; Kuznetsov, Sergei A.; Beruete Díaz, Miguel Upna (Wiley, 2018)   Artículo / Artikulua
      The discovery of extraordinary optical transmission (EOT) through patterned metallic foils in the late 1990s was decisive for the development of plasmonics and cleared the path to employ small apertures for a variety of ...
    • Optimized strain long-period fiber grating (LPFG) sensors operating at the dispersion turning point 

      Del Villar, Ignacio Upna; Fuentes, Omar; Chiavaioli, Francesco; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      Two phenomena for enhancing the sensitivity of longperiod fiber gratings are combined toward an increase of the sensitivity to strain of this type of devices: the dispersion turning point (DTP) and the cladding diameter ...
    • Nanofabrication of phase-shifted Bragg gratings on the end facet of multimode fiber towards development of optical filters and sensors 

      Gallego, E.E.; Ascorbe Muruzabal, Joaquín Upna; Del Villar, Ignacio Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (Elsevier, 2018)   Artículo / Artikulua
      This work describes the process of nanofabrication of phase-shifted Bragg gratings on the end facet of a multimode optical fiber with a pulsed DC sputtering system based on a single target. Several structures have been ...
    • Phase reversal technique applied to fishnet metalenses 

      Pacheco-Peña, Víctor Upna; Minin, Igor V.; Minin, Oleg V.; Beruete Díaz, Miguel Upna (Hindawi, 2018)   Artículo / Artikulua  OpenAccess
      In this work, the fishnet metamaterial is applied to several converging metalenses by combining the zoning, reference phase, and phase reversal techniques. First, the zoning and reference phase techniques are implemented ...
    • Labyrinth metasurface absorber for ultra-high-sensitivity terahertz thin film sensing 

      Jáuregui López, Irati; Rodríguez Ulibarri, Pablo Upna; Urrutia Azcona, Aitor Upna; Kuznetsov, Sergei A.; Beruete Díaz, Miguel Upna (Wiley, 2018)   Artículo / Artikulua
      In this work, a labyrinth metasurface sensor operating at the low‐frequency edge of the THz band is presented. Its intricate shape leads to a high electric field confinement on the surface of the structure, resulting in ...
    • Implementation and operational analysis of an interactive intensive care unit within a smart health context 

      López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Trigo Vilaseca, Jesús Daniel; Astrain Escola, José Javier Upna; Azpilicueta Fernández de las Heras, Leyre Upna; Serrano Arriezu, Luis Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      In the context of hospital management and operation, Intensive Care Units (ICU) are one of the most challenging in terms of time responsiveness and criticality, in which adequate resource management and signal processing ...
    • Metasurface-based ultrathin carpet cloaks for millimeter waves 

      Orazbayev, Bakhtiyar Upna; Mohammadi Estakhri, Nasim; Alù, Andrea; Beruete Díaz, Miguel Upna (2017)   Artículo / Artikulua  OpenAccess
      A metasurface carpet cloak for millimetre-wave range with polarization independent performance is experimentally demonstrated. It is shown that the cloak is able to mimic the ground plane by fully restoring the amplitude ...
    • Cyclic coding for Brillouin optical time-domain analyzers using probe dithering 

      Iribas Pardo, Haritz Upna; Loayssa Lara, Alayn Upna; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien (Optical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      We study the performance limits of mono-color cyclic coding applied to Brillouin optical time-domain analysis (BOTDA) sensors that use probe wave dithering. BOTDA analyzers with dithering of the probe use a dual-probe-sideband ...
    • Response of complementary split ring resonators in composite stratified substrate integrated waveguide 

      Pérez Escudero, José Manuel Upna; Jarauta Ayensa, Eduardo Upna; Falcone Lanas, Francisco Javier Upna; Beruete Díaz, Miguel Upna (American Institute of Physics, 2017)   Artículo / Artikulua  OpenAccess
      In this work, the behavior of a Complementary Split Ring Resonator (CSRR) operating within the quasi-static resonance regime and embedded in a composite stratified Substrate Integrated Waveguide (SIW) with two different ...
    • Experimental and computational study on thermoelectric generators using thermosyphons with phase change as heat exchangers 

      Araiz Vega, Miguel Upna; Martínez Echeverri, Álvaro Upna; Astrain Ulibarrena, David Upna; Aranguren Garacochea, Patricia Upna (Elsevier, 2017)   Artículo / Artikulua
      An important issue in thermoelectric generators is the thermal design of the heat exchangers since it can improve their performance by increasing the heat absorbed or dissipated by the thermoelectric modules. Due to its ...
    • Challenges in wireless system integration as enablers for indoor context aware environments 

      López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Azpilicueta Fernández de las Heras, Leyre Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The advent of fully interactive environments within Smart Cities and Smart Regions requires the use of multiple wireless systems. In the case of user-device interaction, which finds multiple applications such as Ambient ...
    • Humidity sensor based on Bragg gratings developed on the end facet of an optical fiber by sputtering of one single material 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The refractive index of sputtered indium oxide nanocoatings has been altered just by changing the sputtering parameters, such as pressure. These induced changes have been exploited for the generation of a grating on the ...
    • Non-local effects in Brillouin optical time-domain analysis sensors 

      Iribas Pardo, Haritz Upna; Urricelqui Polvorinos, Javier Upna; Mompó Roselló, Juan José Upna; Mariñelarena Ollacarizqueta, Jon Upna; Loayssa Lara, Alayn Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Brillouin optical time-domain analysis (BOTDA) sensors have great potential to provide distributed measurements of temperature and strain over large structures with high spatial resolution and measurement precision. However, ...
    • Binary relations coming from solutions of functional equations: orderings and fuzzy subsets 

      Campión Arrastia, María Jesús Upna; Miguel Turullols, Laura de Upna; García Catalán, Olga Raquel Upna; Induráin Eraso, Esteban Upna; Abrísqueta Usaola, Francisco Javier Upna (World Scientific Publishing Company, 2017)   Artículo / Artikulua
      We analyze the main properties of binary relations, defined o n a nonempty set, that arise in a natural way when dealing with real-valued functions that satisfy certain classical functional equations on two variables. We ...
    • Is there a frontier in sensitivity with lossy mode resonance (LMR) based refractometers? 

      Ozcariz Celaya, Aritz Upna; Ruiz Zamarreño, Carlos Upna; Zubiate Orzanco, Pablo Upna; Arregui San Martín, Francisco Javier Upna (Nature Publishing Group, 2017)   Artículo / Artikulua  OpenAccess
      A tin dioxide thin layer has been studied in order to improve the sensitivity of lossy mode resonances (LMR) based sensors. The effects of the thin film thickness and the polarization of light in a SnO2 coated D-shaped ...
    • Mid-infrared spectroscopy (MIR) for simultaneous determination of fat and protein content in meat of several animal species 

      Lozano Saiz, María; Rodríguez Ulibarri, Pablo Upna; Echeverría Morrás, Jesús Upna; Beruete Díaz, Miguel Upna; Sorolla Ayza, Mario Upna; Beriain Apesteguía, María José Upna (Springer, 2017)   Artículo / Artikulua
      The aim of this research was to study the application of MIR spectroscopy as an alternative to conventional methods to determine fat and protein content. Samples of the main species used to produce meat products were ...