• openAccess   Scalable and Efficient Clustering for Fingerprint-Based Positioning 

      Torres-Sospedra, Joaquín; Quezada Gaibor, Darwin; Nurmi, Jari; Koucheryavy, Yevgeni; Lohan, Elena Simona; Huerta, Joaquin IEEE (2023)
      Abstract: Indoor positioning based on IEEE 802.11 wireless LAN (Wi-Fi) fingerprinting needs a reference data set, also known as a radio map, in order to match the incoming fingerprint in the operational phase with the ...
    • openAccess   Second-harmonic illumination to enhance multispectral digital lensless holographic microscopy 

      Mendoza-Yero, Omel; Carbonell Leal, Miguel; Lancis, Jesús; García Sucerquia, Jorge Optical Society of America (2016-03)
      Multispectral digital lensless holographic microscopy (MDLHM) operating with second-harmonic illumination is shown. Added to the improvement of the spatial resolution of the previously reported MDLHM operating with ...
    • closedAccess   Second-order analysis of anisotropic spatiotemporal point process data 

      Comas Rodríguez, Carlos; Rodríguez-Cortés, Francisco Javier; Mateu, Jorge Wiley (2015-02)
      Second-order orientation methods provide a natural tool for the analysis of spatial point process data. In this paper, we extend to the spatiotemporal setting the spatial point pair orientation distribution function. The ...
    • openAccess   Second-order and local characteristics of network intensity functions 

      Eckardt, Matthias; Mateu, Jorge Springer (2021)
      The last decade has witnessed an increase of interest in the spatial analysis of structuredpoint patterns over networks whose analysis is challenging because of geometricalcomplexities and unique methodological problems. ...
    • closedAccess   Second-order smoothing of spatial point patterns with small sample sizes: a family of kernels 

      Rodríguez-Cortés, Francisco Javier; Mateu, Jorge Springer Verlag (2015-01)
      We consider kernel-based non-parametric estimation of second-order product densities of spatial point patterns. We present a new family of optimal and positive kernels that shows less variance and more flexibility than ...
    • closedAccess   Security and Reliability of Room Occupancy Detection Using Probe Requests in Smart Buildings 

      Fryza, Tomas; Bravenec, Tomáš; Kohl, Zdenek IEEE (2023-04-19)
      We present new approaches for determining occupancy in smart building management systems. The solutions can be applied dually, in civil and military areas, not only for economic management but also in crisis situations ...
    • closedAccess   Security authentication using phase-encoded nanoparticle structures and polarized light 

      Carnicer, Artur; Hassanfiroozi, Amir; Latorre Carmona, Pedro; Huang, Yi-Pai; Javidi, Bahram Optical Society of America (2015)
      Phase-encoded nanostructures such as quick response (QR) codes made of metallic nanoparticles are suggested to be used in security and authentication applications. We present a polarimetric optical method able to authenticate ...
    • closedAccess   Self-exciting point process modelling of crimes on linear networks 

      D'ANGELO, Nicoletta; Payares García, David Enrique; adelfio, giada; Mateu, Jorge SAGE Publications (2022)
      Although there are recent developments for the analysis of first and second-order characteristics of point processes on networks, there are very few attempts in introducing models for network data. Motivated by the analysis ...
    • closedAccess   Self-referenced phase reconstruction proposal of Ghz bandwidth non-periodical optical pulses by in-fiber semi-differintegration 

      Cuadrado Laborde, Christian; Andrés, Miguel V.; Lancis, Jesús Elsevier (2011)
      We propose two new techniques able to retrieve the phase profile of a given temporal optical pulse based on the use of in-fiber semi-differintegral operators, where by semi-differintegration we mean either a 0.5th-order ...
    • closedAccess   Self-similar behavior in semiconductor superlattices 

      Castro-Palacio, Juan Carlos; Villatoro, Francisco R.; Mendoza-Yero, Omel; Velázquez Abad, Luisberis; Monsoriu, Juan A. World Scientific Publishing Company (2012)
      The scattering of particles in fractal superlattices has been analyzed by means of the transfer matrix method. The fractal superlattice consists of alternating layers of semiconductor materials following the rule of a ...
    • openAccess   Self-similar focusing with generalized devil’s lenses 

      Casanova, Cristina; Burlan, Walter D.; Remón, Laura; Calatayud, Arnau; Monsoriu, Juan A.; Mendoza-Yero, Omel Optical Society of America (2011)
      We introduce the generalized devil’s lenses (GDLs) as a new family of diffractive kinoform lenses whose structure is based on the generalized Cantor set. The focusing properties of different members of this family are ...
    • openAccess   Semantic DESCaaS - Extending the Description as a Service Concept to Enable Semantic Annotations 

      Michels, Henry; Roth, Marcell; Beltran Fonollosa, Arturo AGILE (2012)
      Semantic interoperability covers the conflict-free and meaningful exchange of resources by improving the mutual understanding of participants in a communication process. Especially, the communication between humans via ...
    • closedAccess   SEN23E: A Cloudless Geo-Referenced Multi-Spectral Sentinel-2/Sentinel-3 Dataset for Data Fusion Analysis 

      Ibáñez Fernández, Damián; Fernandez-Beltran, Ruben; Pla, Filiberto IEEE (2022-07)
      The availability of geo-referenced coupled data of dif-ferent platforms is essential to train remote sensing (RS) multi-modal classification and bio-phyiscal parameter esti-mation learning methods. To properly develop a ...
    • openAccess   Senior Monitoring: A Real Case of Applying a WiFi Fingerprinting-based Indoor Positioning Method for People Monitoring 

      Montoliu Colás, Raul; Sansano-Sansano, Emilio; Gascó, Arturo; Belmonte-Fernández, Óscar; Caballer Miedes, Antonio CEUR Workshop Proceedings (2019)
      This paper presents our experience on a real case of applying a Wi-Fi fingerprinting-based indoor localization system for monitoring elder people in their own homes. The presented system is part of a broad project called ...
    • openAccess   Sense of place and the city: the case of non-native residents in Lisbon 

      Tang, Vicente; Acedo Sánchez, Albert; Painho, Marco University of Maine (United States) (2021-11-19)
      When immigrants move to a new city, they tend to develop distinct relationships with the urban landscape, which in turn becomes the new setting of their routine-based activities that evolve over time. Previous works in ...
    • openAccess   Sentinel-2 and Sentinel-3 Intersensor Vegetation Estimation via Constrained Topic Modeling 

      Fernandez-Beltran, Ruben; Pla, Filiberto; Plaza, Antonio IEEE (2019-03)
      This letter presents a novel intersensor vegetation estimation framework, which aims at combining Sentinel-2 (S2) spatial resolution with Sentinel-3 (S3) spectral characteristics in order to generate fused vegetation maps. ...
    • openAccess   Sentinel-3 Super-Resolution Based on Dense Multireceptive Channel Attention 

      Fernández, Rafael; Fernandez-Beltran, Ruben; kang, jian; Pla, Filiberto IEEE (2021-07-16)
      The unprecedented availability of remote sensing data from different complementary Sentinel missions provides increasing opportunities to alleviate the spatial limitations of Sentinel-3 (S3) from an intersensor perspective. ...
    • openAccess   Sentinel-3/FLEX Biophysical Product Confidence Using Sentinel-2 Land-Cover Spatial Distributions 

      Fernandez-Beltran, Ruben; Pla, Filiberto; kang, jian; Moreno, Jose; Plaza, Antonio IEEE (2021-03-11)
      The estimation of biophysical variables from remote sensing data raises important challenges in terms of the acquisition technology and its limitations. In this way, some vegetation parameters, such as chlorophyll fluorescence, ...
    • openAccess   SEnviro: A Sensorized Platform Proposal Using Open Hardware and Open Standards 

      Trilles, Sergio; Luján, Alejandro; Belmonte-Fernández, Óscar; Montoliu Colás, Raul; Torres-Sospedra, Joaquín; Huerta, Joaquin MDPI (2015-03)
      The need for constant monitoring of environmental conditions has produced an increase in the development of wireless sensor networks (WSN). The drive towards smart cities has produced the need for smart sensors to be able ...
    • closedAccess   Separable soft shadow mapping 

      Buades, José María; Gumbau Portalés, Jesús; Chover, Miguel Springer (2015-02)
      We propose an efficient technique for rendering visually plausible real-time soft shadows in screen space. First, we propose a novel blocker estimation technique based on a separable filter. Second, our technique performs ...