Now showing items 22-41 of 76

    • Fabrication of Bragg gratings on the end facet of standard optical fibers by sputtering the same material 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; del Villar, Ignacio Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (IEEE, 2016)   Artículo / Artikulua  OpenAccess
      A sputtering process has been applied to deposit quarter-wavelength stacks on the end facet of cleaved optical fibers by using only one sputtering target. Standard multimode optical fibers were used as substrates to fabricate ...
    • A framework for radial data comparison and its application to fingerprint analysis 

      Marco Detchart, Cedric Upna; Cerrón González, Juan Upna; Miguel Turullols, Laura de Upna; López Molina, Carlos Upna; Bustince Sola, Humberto Upna; Galar Idoate, Mikel Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      This work tackles the comparison of radial data, and proposes comparison measures that are further applied to fingerprint analysis. First, we study the similarity of scalar and non-scalar radial data, elaborated on previous ...
    • Fuzzy rule-based classification systems for multi-class problems using binary decomposition strategies: on the influence of n-dimensional overlap functions in the fuzzy reasoning method 

      Elkano Ilintxeta, Mikel Upna; Galar Idoate, Mikel Upna; Sanz Delgado, José Antonio Upna; Bustince Sola, Humberto Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      Multi-class classification problems appear in a broad variety of real-world problems, e.g., medicine, genomics, bioinformatics, or computer vision. In this context, decomposition strategies are useful to increase the ...
    • Giant sensitivity of optical fiber sensors by means of lossy moderesonance 

      Arregui San Martín, Francisco Javier Upna; Del Villar, Ignacio Upna; Ruiz Zamarreño, Carlos Upna; Zubiate Orzanco, Pablo Upna; Matías Maestro, Ignacio Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      Here we show an optical refractometer with a giant sensitivity of 304,360 nm per refractive index unit(nm/RIU). This sensitivity corresponds to a resolution of 3.28 × 10−9RIU if a standard optical spectrumanalyzer with a ...
    • Grating lobes in higher-order correlation functions of arrays of quantum emitters: directional photon bunching 

      Liberal Olleta, Íñigo Upna; Ederra Urzainqui, Íñigo Upna; Ziolkowsky, Richard W. (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      Recent advances in nanofabrication and optical manipulation techniques are making it possible to build arrays of quantum emitters with accurate control over the locations of their individual elements. In analogy with ...
    • Heat pipes thermal performance for a reversible thermoelectric cooler-heat pump for a nZEB 

      Aranguren Garacochea, Patricia Upna; Díaz de Garayo, Sergio; Martínez Echeverri, Álvaro Upna; Araiz Vega, Miguel Upna; Astrain Ulibarrena, David Upna (Elsevier, 2019)   Artículo / Artikulua
      The nZEB standards reduce the energy demand of these buildings to a minimum, obtaining this little energy from renewable resources. Taking these aspect into consideration, a thermoelectric cooler-heat pump is proposed to ...
    • High aperture efficiency wide corrugations bull’s-eye antenna working at 60 GHz 

      Beaskoetxea Gartzia, Unai Upna; Beruete Díaz, Miguel Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      A full metallic Bull’s-Eye (BE) antenna operating at 60 GHz is numerically and experimentally analyzed. The antenna presents wide grooves, rather than narrow ones, which support higher order resonances that lead to a large ...
    • High sensitivity humidity sensor based on cladding-etched optical fiber and lossy mode resonances 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (Elsevier, 2016)   Artículo / Artikulua  OpenAccess
      In this work a high sensitivity optical fiber humidity sensor (OFHS) is presented. The configuration chosen for this purpose is a cladding-etched single mode optical fiber (CE-SMF) coated with a thin film of tin oxide ...
    • 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 ...
    • Implementation and analysis of ISM 2.4 GHz wireless sensor network systems in judo training venues 

      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, 2016)   Artículo / Artikulua  OpenAccess
      In this work, the performance of ISM 2.4 GHz Wireless Sensor Networks (WSNs) deployed in judo training venues is analyzed. Judo is a very popular martial art, which is practiced by thousands of people not only at the ...
    • 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 ...
    • Increasing surface plasmons propagation via photonic nanojets with periodically spaced 3D dielectric cuboids 

      Pacheco Peña, Víctor Upna; Minin, Igor V.; Minin, Oleg V.; Beruete Díaz, Miguel Upna (MDPI, 2016)   Artículo / Artikulua  OpenAccess
      A structure based on periodically arranged 3D dielectric cuboids connected by photonic nanojets (PNJs) is proposed with the aim of increasing the propagation distance of surface plasmon polaritons (SPPs) at the telecom ...
    • Increasing the sensitivity of an optic level sensor with a wavelength and phase sensitive single-mode multimode single-mode (SMS) fiber structure 

      Fuentes, Omar; Del Villar, Ignacio Upna; Vento, José R.; Socorro Leránoz, Abián Bentor Upna; Gallego, E.E.; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      The sensitivity of a liquid level sensor based on a single-mode-multimode-single-mode fiber structure has been increased by hydrofluoric acid etching. The etching process was analyzed and monitored both theoretical and ...
    • Interval-valued Atanassov intuitionistic OWA aggregations using admissible linear orders and their application to decision making 

      Miguel Turullols, Laura de Upna; Bustince Sola, Humberto Upna; Pekala, Barbara; Bentkowska, Urszula; Silva, Ivanoska da; Bedregal, Benjamin; Mesiar, Radko; Ochoa Lezaun, Gustavo Upna (IEEE, 2016)   Artículo / Artikulua  OpenAccess
      Based on the definition of admissible order for interval-valued Atanassov intuitionistic fuzzy sets, we study OWA operators in these sets distinguishing between the weights associated to the membership and those associated ...
    • 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 ...
    • 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 ...
    • 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 ...
    • Linking mathematical morphology and L-fuzzy concepts 

      Alcalde, Cristina; Burusco Juandeaburre, Ana Upna; Bustince Sola, Humberto Upna; Fuentes González, Ramón Upna; Sesma Sara, Mikel Upna (World Scientific, 2017)   Artículo / Artikulua  OpenAccess
      In this paper we study the relation between L-fuzzy morphology and L-fuzzy concepts over complete lattices. In particular, we show how the erosion and dilation operators of the former can be understood in terms of the ...
    • Luminescence-based optical sensors fabricated by means of the layer-by-layer nano-assembly technique 

      Acha Morrás, Nerea de Upna; Elosúa Aguado, César Upna; Matías Maestro, Ignacio Upna; Arregui San Martín, Francisco Javier Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Luminescence-based sensing applications range from agriculture to biology, including medicine and environmental care, which indicates the importance of this technique as a detection tool. Luminescent optical sensors are ...
    • 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 ...