Now showing items 22-37 of 37

    • Photonic nanojets with mesoscale high-index dielectric particles 

      Pacheco-Peña, Víctor Upna; Beruete Díaz, Miguel Upna (AIP Publishing, 2019)   Artículo / Artikulua  OpenAccess
      In this work, we demonstrate the ability of high-index dielectric particles immersed in air to generate photonic nanojets with extreme resolution (∼0.06λ0). Both 2D (cylindrical) and 3D (spherical) particles are analyzed, ...
    • 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. ...
    • Real time measuring system of multiple chemical parameters using microstructured optical fibers based sensors 

      López Aldaba, Aitor Upna; López Torres, Diego Upna; Elosúa Aguado, César Upna; Arregui San Martín, Francisco Javier Upna; Auguste, Jean-Louis; Jamier, Raphael; Roy, Philippe; López-Amo Sáinz, Manuel Upna (IEEE, 2018)   Artículo / Artikulua  OpenAccess
      In this paper, a multiplexing system for simultaneous interrogation of optical fiber sensors which measure different parameters is presented and validated. The whole system has been tested with 6 different sensing heads ...
    • 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 ...
    • Robust and accurate 2D-tracking-based 3D positioning method: application to head pose estimation 

      Ariz Galilea, Mikel; Villanueva Larre, Arantxa Upna; Cabeza Laguna, Rafael Upna (Elsevier, 2019)   Artículo / Artikulua  OpenAccess
      Head pose estimation (HPE) is currently a growing research field, mainly because of the proliferation of human–computer interfaces (HCI) in the last decade. It offers a wide variety of applications, including human behavior ...
    • Robust multisampled capacitor voltage active damping for grid-connected power converters 

      Samanes Pascual, Javier; Urtasun Erburu, Andoni Upna; Gubía Villabona, Eugenio Upna; Petri, Alberto (Elsevier, 2019)   Artículo / Artikulua
      The derivative feedback of the capacitor voltage is one of the most extended active damping strategies, used to eliminate stability problems in grid-connected power converters with an LCL filter. This strategy is equivalent ...
    • 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, ...
    • Steering surface plasmons with a graded index dielectric medium 

      Beruete Díaz, Miguel Upna; Pacheco-Peña, Víctor Upna (IOP Publishing, 2018)   Artículo / Artikulua  OpenAccess
      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 ...
    • Strong angular dependence of resonant states in 2D dielectric cylinder rings 

      Andueza Unanua, Ángel María; Pérez Conde, Jesús Upna; Sevilla Moróder, Joaquín Upna (AIP Publishing, 2018)   Artículo / Artikulua
      We investigate collective resonators made of dielectric cylinders assembled as two-dimensional regular octagons and decagons. These structures exhibit collective resonance states that change their intensity with the incident ...
    • Study on isolation improvement between closely-packed patch antenna arrays based on fractal metamaterial electromagnetic bandgap structures 

      Alibakhshikenari, Mohammad; Virdee, Bal S.; See, Chan H.; Abd-Alhameed, Raed; Ali, Abdul; Hussein Ali, Ammar; Falcone Lanas, Francisco Javier Upna; Limiti, Ernesto (Institution of Engineering and Technology, 2018)   Artículo / Artikulua  OpenAccess
      A decoupling metamaterial (MTM) configuration based on fractal electromagnetic-bandgap (EMBG) structure is shown to significantly enhance isolation between transmitting and receiving antenna elements in a closely-packed ...
    • Super class AB RFC OTA with adaptive local common-mode feedback 

      Garde Luque, María Pilar; López Martín, Antonio Upna; Carvajal, Ramón G.; Ramírez-Angulo, Jaime (Institution of Engineering and Technology, 2018)   Artículo / Artikulua  OpenAccess
      A super class AB recycling folded cascode operational transconductance amplifier is presented. It employs local common-mode feedback using two matched tuneable active resistors, allowing to adapt the amplifier to different ...
    • Supercapacitors: electrical characteristics, modelling, applications and future trends 

      Berrueta Irigoyen, Alberto; Ursúa Rubio, Alfredo Upna; San Martín Biurrun, Idoia Upna; Eftekhari, Ali; Sanchís Gúrpide, Pablo Upna (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      Energy storage systems are playing an increasingly important role in a variety of applications, such as electric vehicles or grid-connected systems. In this context, supercapacitors (SCs) are gaining ground due to their ...
    • 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 ...
    • Virtual FBGs using saturable absorbers for sensing with fiber lasers 

      Rodríguez Cobo, L.; Pérez Herrera, Rosa Ana Upna; Quintela, M. A.; Ruiz Lombera, Rubén; López-Amo Sáinz, Manuel Upna; López Higuera, José Miguel (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      The spectral narrowing of Fiber Bragg Gratings (FBGs) introduced by unpumped Er-doped fiber (EDF) was analyzed for fiber lasers (FL). Owing to spatial hole burning (SHB), the spectral response of a virtual FBG can be ...
    • A water content continuous monitoring of grapevine xylem tissue using a portable low-power cost-effective FMCW radar 

      Quemada Mayoral, Carlos; García González, Cebrián; Iriarte Galarregui, Juan Carlos Upna; Marín Ederra, Diana; Gastón Beraza, Diego; Miranda Jiménez, Carlos Upna; Gonzalo García, Ramón Upna; Maestrojuán Biurrun, Itziar Upna; Santesteban García, Gonzaga Upna; Ederra Urzainqui, Íñigo Upna (IEEE, 2019)   Artículo / Artikulua
      This paper presents the real-time monitoring of a grapevine’s water content that flows up through the xylem tissue by means of a frequency-modulated continuous-wave (FMCW) radar. The application of an optimization process, ...
    • Watt-level green random laser at 532  nm by SHG of Yb-doped fiber laser 

      Rota Rodrigo, Sergio Upna; Gouhier, B.; Dixneuf, C.; Antoni Micollier, L.; Guiraud, G.; Leandro González, Daniel Upna; López-Amo Sáinz, Manuel Upna; Traynor, N.; Santarelli, G. (Optical Society of America, 2018)   Artículo / Artikulua  OpenAccess
      We have developed a Watt-level random laser at 532 nm. The laser is based on a 1064 nm random distributed ytterbium-gain assisted fiber laser seed with a 0.35 nm line-width and 900 mW polarized output power. A study for ...