Now showing items 34-53 of 59

    • Narrowband characterization of near-ground radio channel for wireless sensors networks at 5G-IoT bands 

      Klaina, Hicham; Vazquez Alejos, Ana; Aghzout, Otman; Falcone Lanas, Francisco Javier Upna (MDPI, 2018)   Artículo / Artikulua  OpenAccess
      In this contribution, a narrowband radio channel model is proposed for rural scenarios in which the radio link operates under near-ground conditions for application in wireless sensor networks dedicated to smart agriculture. ...
    • On the design and performance evaluation of automatic traffic report generation systems with huge data volumes 

      Vega, Carlos; Miravalls-Sierra, Eduardo; Julián-Moreno, Guillermo; López de Vergara, Jorge E.; Magaña Lizarrondo, Eduardo Upna; Aracil Rico, Javier Upna (Wiley, 2018)   Artículo / Artikulua  OpenAccess
      In this paper we analyze the performance issues involved in the generation of automated traffic reports for large IT infrastructures. Such reports allow the IT manager to proactively detect possible abnormal situations ...
    • On the performance of an ENZ-based sensor using transmission line theory and effective medium approach 

      Pacheco-Peña, Víctor Upna; Beruete Díaz, Miguel Upna; Rodríguez Ulibarri, Pablo Upna; Engheta, Nader (IOP Publishing, 2019)   Artículo / Artikulua  OpenAccess
      In this paper we perform an in-depth theoretical studyofa sensing platform based on epsilon-near- zero (ENZ) metamaterials. The structure proposed for sensing is a narrow metallic waveguide channel. An equivalent circuit ...
    • On the stability of advanced power electronic converters: the Generalized Bode Criterion 

      Lumbreras Magallón, David Upna; Barrios Rípodas, Ernesto Upna; Urtasun Erburu, Andoni Upna; Ursúa Rubio, Alfredo Upna; Marroyo Palomo, Luis Upna; Sanchis Gúrpide, Pablo Upna (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      A key factor in the design of power electronic converters is the development of control systems and, in particular, the determination of their stability. Due to ease of application, the Bode criteria are currently the most ...
    • Optical fiber lasers assisted by microdrilled optical fiber tapers 

      Pérez Herrera, Rosa Ana Upna; Pallarés Aldeiturriaga, D.; Júdez Colorado, Aitor Upna; Rodríguez Cobo, L.; López-Amo Sáinz, Manuel Upna; López Higuera, José Miguel (Optical Society of America, 2019)   Artículo / Artikulua
      In this Letter, we present an analysis of the backscattering generated in a microdrilled tapered fiber within a short-linear-cavity fiber laser. We propose and experimentally demonstrate a fiber cavity laser based on a ...
    • 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, ...
    • Quasi-distributed vibration sensing using OFDR and weak reflectors 

      Zhu, Mengshi; Leandro González, Daniel Upna; López-Amo Sáinz, Manuel Upna; Murayama, Hideaki (Optical Soc iety of America, 2019)   Artículo / Artikulua
      The authors proposed a quasi-distributed vibration sensing technique using in-line weak reflectors and optical frequency domain reflectometry (OFDR). As a result, they achieved an 8 kHz measurable vibration frequency with ...
    • Ransomware early detection by the analysis of file sharing traffic 

      Morató Osés, Daniel Upna; Berrueta Irigoyen, Eduardo Upna; 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 Upna; 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 Upna; 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 Upna; 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, ...
    • Spectral shadowing suppression technique in phase-OTDR sensing based on weak fiber Bragg grating array 

      Miguel Soto, Verónica de Upna; Jason, Johan; Kurtoglu, Deniz; López-Amo Sáinz, Manuel Upna; Wuilpart, Marc (Optical Society of America, 2019)   Artículo / Artikulua  OpenAccess
      A postprocessing procedure is presented to suppress spectral shadowing in phase-OTDR sensing systems based on a weak fiber Bragg grating array. A complete theoretical analysis of the interfering signals has been carried ...
    • 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 Upna; Pérez Conde, Jesús Upna; Sevilla Moróder, Joaquín Upna (AIP Publishing, 2018)   Artículo / Artikulua  OpenAccess
      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 Upna; 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 ...
    • Super-wide impedance bandwidth planar antenna for microwave and millimeter-wave applications 

      Alibakhshikenari, Mohammad; Virdee, Bal S.; See, Chan H.; Abd-Alhameed, Raed; Falcone Lanas, Francisco Javier Upna; Limiti, Ernesto (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      A feasibility study of a novel configuration for a super-wide impedance planar antenna is presented based on a 2 × 2 microstrip patch antenna (MPA) using CST Microwave Studio. The antenna comprises a symmetrical arrangement ...
    • Supercapacitors: electrical characteristics, modelling, applications and future trends 

      Berrueta Irigoyen, Alberto Upna; Ursúa Rubio, Alfredo Upna; San Martín Biurrun, Idoia Upna; Eftekhari, Ali; Sanchis 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 ...