Now showing items 59-76 of 76

    • Ransomware early detection by the analysis of file sharing traffic 

      Morató Osés, Daniel Upna; Berrueta Irigoyen, Eduardo; Magaña Lizarrondo, Eduardo Upna; Izal Azcárate, Mikel Upna (Elsevier, 2018)   Artículo / Artikulua  OpenAccess
      Crypto ransomware is a type of malware that locks access to user files by encrypting them and demands a ransom in order to obtain the decryption key. This type of malware has become a serious threat for most enterprises. ...
    • Recent developments in fiber optics humidity sensors 

      Ascorbe Muruzabal, Joaquín Upna; Corres Sanz, Jesús María Upna; Arregui San Martín, Francisco Javier Upna; Matías Maestro, Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      A wide range of applications such as health, human comfort, agriculture, food processing and storage, and electronic manufacturing, among others, require fast and accurate measurement of humidity. Sensors based on optical ...
    • Remote access protocols for Desktop-as-a-Service solutions 

      Magaña Lizarrondo, Eduardo Upna; Sesma Gracia, Iris; Morató Osés, Daniel Upna; Izal Azcárate, Mikel Upna (Public Library of Science, 2019)   Artículo / Artikulua  OpenAccess
      The use of remote desktop services on virtualized machines is a general trend to reduce the cost of desktop seats. Instead of assigning a physical machine with its operating system and software to each user, it is considerably ...
    • 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 ...
    • Sensitivity enhancement in low cutoff wavelength long-period fiber gratings by cladding diameter reduction 

      Del Villar, Ignacio Upna; Partridge, Matthew; Rodríguez, Wenceslao; Fuentes, Omar; Socorro Leránoz, Abián Bentor Upna; Díaz Lucas, Silvia Upna; Corres Sanz, Jesús María Upna; James, Stephen; Tatam, Ralph (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      The diameter of long-period fiber gratings (LPFGs) fabricated in optical fibers with a low cutoff wavelength was be reduced by hydrofluoric acid etching, enhancing the sensitivity to refractive index by more than a factor ...
    • Sensitivity optimization with cladding-etched long period fiber gratings at the dispersion turning point 

      Del Villar, Ignacio Upna; Cruz, José Luis; Socorro Leránoz, Abián Bentor Upna; Corres Sanz, Jesús María Upna; Matías Maestro, Ignacio Upna (Optical Society of America, 2016)   Artículo / Artikulua  OpenAccess
      This work presents a refractive index sensor based on a long period fiber grating (LPFG) made in a reduced cladding fiber whose low order cladding modes have the turning point at large wavelengths. The combination of ...
    • A simplified design inline microstrip-to-waveguide transition 

      Ederra Urzainqui, Íñigo Upna; Gonzalo García, Ramón Upna; Pérez Escudero, José Manuel Upna; Torres García, Alicia E. Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      A simplified design of an inline transition between microstrip and rectangular waveguide is presented in this paper. The transition makes use of a dielectric filled rectangular waveguide (DFRW) as an intermediate step, ...
    • Spatial characterization of radio propagation channel in urban vehicle-to-infrastructure environments to support WSNs deployment 

      Granda, Fausto; Azpilicueta Fernández de las Heras, Leyre Upna; Vargas Rosales, César; López Iturri, Peio Upna; Aguirre Gallego, Erik Upna; Astrain Escola, José Javier Upna; Villadangos Alonso, Jesús Upna; Falcone Lanas, Francisco Javier Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Vehicular ad hoc Networks (VANETs) enable vehicles to communicate with each other as well as with roadside units (RSUs). Although there is a significant research effort in radio channel modeling focused on vehicle-to-vehicle ...
    • Steering surface plasmons with a graded index dielectric medium 

      Beruete Díaz, Miguel Upna; Pacheco-Peña, Víctor Upna (IOP Publishing, 2018)   Artículo / Artikulua
      The arbitrary control of surface plasmon (SP) propagation has become an intense research topic for several decades. This is due to the fact that they can be used in a variety of fields such as optical trapping, nanoantennas ...
    • Study of optical fiber sensors for cryogenic temperature measurements 

      Miguel Soto, Verónica de; Leandro González, Daniel Upna; López Aldaba, Aitor Upna; Beato López, Juan Jesús; Pérez de Landazábal Berganzo, José Ignacio; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      In this work, the performance of five different fiber optic sensors at cryogenic temperatures has been analyzed. A photonic crystal fiber Fabry-Pérot interferometer, two Sagnac interferometers, a commercial fiber Bragg ...
    • Super-oscillatory metalens at terahertz for enhanced focusing with reduced side lobes 

      Legaria Lerga, Santiago; Pacheco-Peña, Víctor Upna; Beruete Díaz, Miguel Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      In this paper, we design and numerically demonstrate an ultra-thin super-oscillatory metalens with a resolution below the diffraction limit. The zones of the lens are implemented using metasurface concepts with hexagonal ...
    • TBDClust: time-based density clustering to enable free browsing of sites in pay-per-use mobile Internet providers 

      Torres, Luis Miguel; Magaña Lizarrondo, Eduardo Upna; Morató Osés, Daniel Upna; García-Jiménez, Santiago Upna; Izal Azcárate, Mikel Upna (Elsevier, 2017)   Artículo / Artikulua  OpenAccess
      The World Wide Web has evolved rapidly, incorporating new content types and becoming more dynamic. The contents from a website can be distributed between several servers, and as a consequence, web traffic has become ...
    • Technical and environmental characterization of hydraulic and alkaline binders 

      Espuelas Zuazu, Sandra; Echeverría, Angel María; Marcelino Sádaba, Sara; Prieto Cobo, Eduardo; Seco Meneses, Andrés (Elsevier, 2018)   Artículo / Artikulua
      Portland cement is a widely used binder in construction and building applications because of its good properties. Despite its convenience as construction material, the social demands and policies trends are requesting a ...
    • Temperature sensor using a multiwavelength erbium-doped fiber ring laser 

      Díaz Lucas, Silvia Upna; San Fabián García, Noé; Socorro Leránoz, Abián Bentor Upna; Matías Maestro, Ignacio Upna (Hindawi, 2017)   Artículo / Artikulua  OpenAccess
      A novel temperature sensor is presented based on a multiwavelength erbium-doped fiber ring laser.The laser is comprised of fiber Bragg grating reflectors as the oscillation wavelength selecting filters.The performance of ...
    • THz sensing with anomalous extraordinary optical transmission hole arrays 

      Jáuregui López, Irati; Rodríguez Ulibarri, Pablo Upna; Kuznetsov, Sergei A.; Nikolaev, Nazar A.; Beruete Díaz, Miguel Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      Subwavelength hole array (HA) metasurfaces support the so-called extraordinary optical transmission (EOT) resonance that has already been exploited for sensing. In this work, we demonstrate the superior performance of a ...
    • Tunable deflection and asymmetric transmission of THz waves using a thin slab of graphene-dielectric metamaterial, with and without ENZ components 

      Serebryannikov, Andriy E.; Hajian, Hodjat; Beruete Díaz, Miguel Upna; Ozbay, Ekmel; Vandenbosch, Guy A. E. (Optical Society of America, 2018)   Artículo / Artikulua  OpenAccess
      Tunable deflection of obliquely incident, linearly polarized terahertz waves is theoretically studied in a wide frequency range around 20 THz, by combining a thin slab of graphene-dielectric metamaterial (with ten layers ...
    • Unbalanced interval-valued OWA operators 

      Miguel Turullols, Laura de Upna; Bustince Sola, Humberto Upna; Barrenechea Tartas, Edurne Upna; Pagola Barrio, Miguel Upna; Fernández Fernández, Francisco Javier Upna (Springer Berlin Heidelberg, 2016)   Artículo / Artikulua  OpenAccess
      In this work, we introduce a new class of functions defned on the interval-valued setting. These functions extend classical OWA operators but allow for diferent weighting vectors to handle the lower bounds and the ...
    • Wideband backscattering reduction at terahertz using compound reflection grating 

      Orazbayev, Bakhtiyar Upna; Rodríguez Ulibarri, Pablo Upna; Beruete Díaz, Miguel Upna (Optical Society of America, 2017)   Artículo / Artikulua  OpenAccess
      Backscattering reduction is usually achieved by using either absorbers or diffractions gratings at the expense of a narrow bandwidth. In this paper, we propose a different strategy based on a metallic compound reflection ...