Comunicaciones y ponencias de congresos ISC - ISC biltzarretako komunikazioak eta txostenak
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Publication Embargo Insights into the q Exponent in Power Measure with Choquet-based generalizations for classification problems(Springer, 2025-07-09) Lucca, Giancarlo; Asmus, Tiago da Cruz; Marco Detchart, Cedric; Santos, Helida; Camargo, Heloisa A.; Yamin, Adenauer; Reiser, Renata; Bustince Sola, Humberto; Pintanel, Alice ; Pereira Dimuro, Graçaliz; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISCChoquet-integrals are averaging aggregation functions based on a fuzzy measure that accounts for both the significance of each attribute being aggregated and the interactions between the variables. The effectiveness of a fuzzy measure can be characterized by its accuracy in modeling the relationship or association degree among the elements to be aggregated. In the literature, it is known that amid conventional fuzzy measures, the Power Measure (PM) presents statistically superior performance. This study explores the q exponent impact in the PM on the performance of different Choquet-based integrals when used in fuzzy rulebased classification systems. We aim to analyze how fixed q values influence classification accuracy across thirty-three benchmark datasets. The updated results reveal that smaller q values (e.g., q = 0.1 and q = 0.5) continue to yield superior accuracy, while larger values (q ≥ 100) tend to a performance stabilization. Among the tested methods, the generalization named CF1F2-integral achieves the highest classification accuracy, effectively adapting to different parameter settings.Publication Open Access Q/V-Band Gap-Waveguide-based circularly-polarized antenna(IEEE, 2025-05-21) Leoz-Beltrán, Iñigo; Iriarte Galarregui, Juan Carlos; Pérez Quintana, Dayan; Teberio Berdún, Fernando; Beruete Díaz, Miguel; Ederra Urzainqui, Íñigo; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PRO-UPNA 11893This paper presents the design of an all-metal Gap Waveguide-based antenna. The design is intended for satellite communications as it covers the Q/V-Band, comprised between 37.5 and 42.5 GHz and between 47.5 and 52.4 GHz. This antenna operates with circular polarization, featuring an Axial Ratio below 1.5 dB at both frequency bands. The design includes a transition from an standard WR waveguide to a Ridge Gap Waveguide. The simulation of the whole system shows return losses higher than 10 dB at the bands of interest. Furthermore, this unit cell antenna achieves a maximum gain of 11.9 dB at 48.8 GHz.Publication Open Access A SiGe integrated active phased array antenna for a 183GHz water-vapor radiometer(IEEE, 2025-05-21) Herrera-Martín, Juan M.; Urain, Álvaro; Río, David del; González Posadas, Vicente; Ederra Urzainqui, Íñigo; Teniente Vallinas, Jorge; Berenguer, Roc; Segovia-Vargas, Daniel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCMillimeter-wave radiometers can benefit from state-of-the-art on-chip technologies to construct a fully integrated front-end at frequencies above 100 GHz. The first step is to integrate a fully capable antenna design with a complex low-low noise amplifier in the same technology. This paper presents the integration simulation of a passive antenna array in IHP's SiGe 130 nm BiCMOS SG13G2 process and a 3-stage low-noise amplifier using the same technology. The final seamlessly integrated design proves to be a viable first building block for a future complete radiometer frontend-on-a-chip for frequencies exceeding 100 GHz.Publication Open Access Robust tuning of cascaded PI controllers for a grid-forming DFIG wind turbine(IEEE, 2025-11-25) El Hamzaoui, Ismail; López Taberna, Jesús; Samanes Pascual, Javier; Gubía Villabona, Eugenio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis paper presents a systematic tuning method for cascaded PI controllers in Grid-Forming (GFM) Doubly- Fed Induction Generator (DFIG) wind turbines. The approach emphasizes control parameter range selection as key to achieving robust stability. Unlike reviewed methods that rely on arbitrarily defined search spaces for the controller gains, this approach preconditions control parameters calculating them based on achievable open-loop cutoff frequency and phase margin ranges. Further refinement is achieved by filtering the calculated search space based on closed-loop stability across varying grid strengths and rotational speeds. This ensures robustness across multiple operating conditions. Optimized settling time and overshoot is found using a set of RMSE-based cost functions. Tuning and performance validation are conducted using a full-order smallsignal model and EMT simulations in Simulink.Publication Open Access Rayleigh signature interrogation in time-domain DAS sensors using the short-frequency Fourier transform(SPIE, 2025-05-22) Sharif, Vahid; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCWe present a general method to determine the dependence of Rayleigh backreflection in an optical fiber on position and optical frequency. It is based on applying the so-called short-frequency Fourier transform to signals obtained from coherent optical time-domain reflectometry (COTDR) measurements. The proposed method enables the implementation of distributed acoustic sensors (DAS) with high linearity, spatial resolution, and measurement frequency, while being immune to signal fading. Additionally, the technique is compatible with both conventional COTDR setups and those employing pulse compression, including phase-coded compression waveforms. We experimentally demonstrate the technique with DAS measurements of a 50-km sensing fiber, achieving a 2-m spatial resolution and a sensitivity of 137 p epsilon/root Hz using a pulse-compression COTDR with a P4 phase-coded compression waveform.Publication Open Access Role of thin film refractive index contrast in the design and performance of nano-photonic crystal D-shaped fiber devices for label-free biosensing(SPIE, 2025-05-22) Del Villar, Ignacio; González-Valencia, Esteban; Kwietniewski, Norbert; Burnat, Dariusz; Borri, Claudia; Singh, Rukmani; Dabagh, Shadab; Armas, Dayron; Pitula, Emil; Janik, Monika; Matías Maestro, Ignacio; Giannetti, Ambra; Torres, Pedro; Smietana, Mateusz; Chiavaioli, Francesco; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCAchieving a high figure of merit alongside exceptional sensitivity is critical for advancing optical biosensors capable of ultra-low limits of detection. In this work, we investigate the performance of D-shaped single-mode fiber devices coated with 1D photonic crystal stacks. These nano-assembled layers, composed of alternating high- and low-refractive-index (RI) materials, enable the excitation of Bloch surface waves (BSWs). By systematically varying the RI contrast between the layers, we demonstrate that while a moderate increase in RI contrast improves sensitivity and narrows the full width at half maximum (FWHM) of the BSW resonance, the sensitivity tends to stabilized as we further increase the RI contrast, while the FWHM still can be pushed towards a higher FoM. Real-world applicability is validated through the detection of immunoglobulin G (IgG) at record-low concentrations of 70 aM, leveraging the solution as a versatile, operando, high-performance biosensing platform.Publication Open Access Reliable, doped hybrid xerogel-based optical fibre sensor for pH monitoring for industry(SPIE, 2025-05-22) Rosales Reina, María Beatriz; Whittaker, N.; López Torres, Diego; Elosúa Aguado, César; Reinoso, Santiago; Sun, Tong; Grattan, Kenneth T. V.; Garrido Segovia, Julián José; Ciencias; Zientziak; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaA new optical fibre pH sensor has been developed based on incorporating the pH indicator in a hybrid siliceous xerogel. Here the hydrophobic siliceous materials were fabricated using the sol-gel method, employing an optimal percentage of organic precursor moieties, propyltriethoxysilane:tetraetoxysilane, then doping it with three different pH indicators (phenolphthalein, bromophenol blue and cyanidin blue), to create three different optical fibre sensor systems (5pTEOSPH, 5pTEOSBF and 5pTEOSCB). These pH sensors exhibit important features needed by industry: fast response times, minimal dye leaching, good stability, a high level of reproducibility, and reversibility in response. Sensors of this type have a number of important potential uses in different applications in industry today.Publication Open Access Time-transformed spectral analysis for multiparametric sensing using a single antiresonant interferometer(SPIE, 2025-05-22) Jaso Gallego, Isabel; Sánchez González, Arturo; Bravo Acha, Mikel; Pérez Herrera, Rosa Ana; Leandro González, Daniel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis work explores the potential of spectral composition analysis in the time-transformed domain for multiparametric sensing using a single in-line hollow-core interferometer. By effectively distinguishing between antiresonance guidance and Fabry Perot-induced contributions, this approach allows simultaneous measurement of two independent parameters. The sensor, featuring polyimide coating, was characterized during humidity cycles at varying temperatures by monitoring phase variations in the transformed domain. The distinct sensitivities of antiresonance and Fabry-Perot components allowed the determination of temperature and relative humidity using a multiparametric linear model, achieving good agreement with experimental results and underscoring its robustness for multiparametric sensing applications.Publication Open Access Polarization-switched fiber optic ring laser for L-band multiwavelength remote sensing applications(SPIE, 2025-05-22) Pérez Herrera, Rosa Ana; Janices Chamizo, Iñaki; San Miguel Zarraluqui, Uxue; Salinas Anguiano, Alvaro; Sánchez González, Arturo; Erro Betrán, María José; Tainta Ausejo, Santiago; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThis work presents the experimental demonstration of a three-channel remote sensor that operates in the L-band. It is based on a fiber ring laser cavity, formed by a semiconductor optical amplifier and three fiber Bragg gratings used both for the selection of the operating wavelengths and the sensing. A polarization-controller allows the activation of one, two or the three emission wavelengths simultaneously. The sensing elements can be situated in a remote localization, without compromising the temperature sensitivity of the experimental setup. To validate this functionality, a 25 km standard single-mode fiber optic reel is incorporated between the FBG-based sensors and the cavity, demonstrating the system's ability to perform long-range sensing while preserving signal integrity and operational reliability.Publication Open Access Urban water leakage detection system based on distributed acoustic sensing over dark fiber networks(Optica Publishing Group, 2025) Sharif, Vahid; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCA novel system for automatically detecting leaks in urban water supply networks is proposed and experimentally demonstrated in a real-world scenario. It leverages the extensive fiber optic access network infrastructure already available.Publication Open Access "Yo quiero ser científica": a creative way to inspire girls in science(IEEE, 2020-06-25) Jurío Munárriz, Aránzazu; Catalán Ros, Leyre; San Martín Biurrun, Idoia; Aranguren Garacochea, Patricia; Martínez Ramírez, Alicia; Díaz Lucas, Silvia; Barrenechea Tartas, Edurne; Gómez Fernández, Marisol; Pérez Artieda, Miren Gurutze; Ingeniería; Ingeniaritza; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISCThe number of women in scientific and technological careers is quite small compared to the number of men in the same careers. To equalize these numbers, the Public University of Navarra started a new initiative in 2017. The goal of this project is to make more-women in STEM visible, in order to serve as example for the young girls. It is brought to life by means of a theatre play called “Yo quiero ser científica” (translated as “I want to be a female scientist”). This play is divided into two parts: in the first one 9 teachers perform the role of 9 historical female scientists, by means of 9 monologues; in the second part, the same 9 teachers tell their experience as contemporary scientists. The feedback obtained through surveys, a contest and a final debate with the attendees show that this kind on initiatives are really necessary.Publication Open Access Federated Fuzzy k-nearest neighbor for classification and regression(IEEE, 2025-09-11) Urío Larrea, Asier; Pereira Dimuro, Graçaliz; Bustince Sola, Humberto; Andreu-Pérez, Javier; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaThis paper introduces Federated Fuzzy k-Nearest Neighbors algorithms, with one variant designed for classification tasks and another for regression tasks. The federated nature of FedFKNN enables collaborative learning while preserving privacy by keeping sensitive data local to the devices. In our proposal, the central server sends the query to each client. The clients process the query using the k-Nearest Neighbors (k-NN) algorithm locally and return their results to the server. Finally, the server aggregates these results, following the corresponding k-NN algorithm, to produce the final output. Experimental results demonstrate the effectiveness of the federated approach, outperforming the results of a non-collaborative local learning approach.Publication Open Access Towards analysing climate change temperature patterns through stream clustering methods(IEEE, 2024-06-26) Urío Larrea, Asier; Pereira Dimuro, Graçaliz; Andreu-Pérez, Javier; Camargo, Heloisa A.; Bustince Sola, Humberto; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaClimate change has an effect on the environmental conditions of different regions. Being able to track these changes is a powerful tool for adapting to evolving conditions. Weather data is continuously generated across multiple stations around the world, providing valuable information on climate time-varying patterns. Studying this data stream enables us to understand the new climate patterns better. This paper explores, through a stream clustering algorithm, the potential of employing weather data in different geographical locations to track the change in climate patterns in the Spanish region of Navarre over the last 20 years. The case study showed the applicability of stream methods to the incremental segmentation of geographical regions based on their climatology factors. In this study, we have found that the climate of Navarre is homogenising into the particular climate of southwestern regions, which is expanding. This particular finding may raise concerns about the time-varying impact that climate change is having on Navarre regions, where large parts of its geography can be grouped into a single climate.Publication Open Access Grouping indices: definition, properties and construction methods(IEEE, 2024-08-05) Pereira Dimuro, Graçaliz; Santos, Helida; Urío Larrea, Asier; Da Cruz Asmus, Tiago; Lucca, Giancarlo; Camargo, Heloisa A.; Parodi, Maria Eugênia; Bustince Sola, Humberto; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISCZadeh has defined its consistency index OZ in order to compare two fuzzy subsets A and B of a referential set U, in the sense that “The lower OZ (A, B) is, the closer to ∅ A ∩ B is.” Several axiomatizations of this concept can be found in the literature, in terms of overlap indices, allowing its application in different contexts, as in classification and clustering. The present work, in an opposite direction, introduces the grouping index, a comparison index G of two fuzzy subsets A and B that provides a measure of the proximity of the fuzzy union of A and B to the referential set U, that is, ‘the higher G(A, B) is, the closer to U A∪ B is.” Many important properties are analyzed, and construction methods are presented, whereas establishing the formal relation between overlap and grouping indices via duality. The theory is illustrated by several detailed examples.Publication Open Access Capillary-based optical fiber sensor for turbidity measurement(SPIE, 2025-05-22) Vanegas Tenezaca, Evelyn Dayanara; Galarza Galarza, Marko; Dauliat, Romain; Jamier, Raphael; Roy, Philippe; Cobo, Adolfo; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis work introduces an innovative capillary or hollow core-based sensor designed to measure turbidity by using the reflection of light in its cladding. The structure consists of two different capillary sections and has been optimized to maximise the interaction of light with the external liquid. Experimentation includes data collection from different turbidity levels using the reflected spectrum. To improve the measuring results, machine learning is implemented, exploring the effectiveness of various algorithms and neural network architectures to achieve a good root mean square error.Publication Open Access Optical fiber laser sensor for torsion measurement using a three-core fiber and a nanocrystals-based reflector(SPIE, 2025-05-22) Correa Serrano, Ángel Ignacio; Vento Álvarez, José Raúl; Galarza Galarza, Marko; Sánchez González, Arturo; Dauliat, Romain; Jamier, Raphael; Roy, Philippe; Humbert, Georges; Pérez Herrera, Rosa Ana; López-Amo Sáinz, Manuel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis study presents a novel and highly sensitive torsion sensor based on a multicore fiber (MCF) inside a Sagnac interferometer, which acts both as a mirror and a sensor head of a fiber ring laser. This laser sensor configuration also incorporates a distributed reflector consisting of an optical fiber segment doped with ZnGa2O4 nanocrystals, enhancing the overall performance. The sensor demonstrates high sensitivity to torsion across a range of 0° to 150°. The phase analysis in the 0°-50° range achieves a sensitivity of 0.08 rad/º. A Machine Learning Integration, with a function-fitting neural network, shows a detection limit of 0.06°.Publication Open Access Remote power over fiber electro-mechanical modulation for enabling hybrid sensor networks(SPIE, 2025-05-22) Rodríguez Rodríguez, Armando; López-Amo Sáinz, Manuel; Bravo Acha, Mikel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis work presents a power-efficient solution based on Power over Fiber technology that combines and enables the use of electronic devices in fiber optic networks. The optical carrier is modulated via a microelectromechanical variable optical attenuator, using the processed sensor data, which is encoded in a frequency shift keying technique. To illustrate the concept, a 50-km remote environmental station is powered by energy harvesting techniques to provide the requisite power, and a low-power microcontroller encodes the data from electronic sensors. The data was successfully retrieved, achieving data rates of up to 1.5 kbps.Publication Open Access Microdisplacement sensor based on a processed optical fiber by an ultrafast laser-assisted etching method(SPIE, 2025-05-22) Pérez Herrera, Rosa Ana; Roldán Varona, Pablo; Sánchez González, Arturo; Gómez-Galdós, C.; López-Amo Sáinz, Manuel; López Higuera, José Miguel; Rodríguez Cobo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCIn this work, a fabrication technique for microchannel-based reflectors used as an optical fiber sensor is demonstrated by using a processed optical fiber by an ultrafast laser-assisted etching method. This microdisplacement sensor was experimentally demonstrated to have an outstanding resolution of 5.9 rad/μm in the measurement range from 0 to 80 microns, by using the fast Fourier transform (FFT) measuring method.Publication Open Access Active damping strategies for mitigating resonances in offshore wind farms: a comparative study of PWM and SHEPWM(HAL, 2025-05-23) Pascual Iglesias, Iñigo; Ramos Arocena, Naroa; Gubía Villabona, Eugenio; López Taberna, Jesús; Samanes Pascual, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISCThis paper presents an active damping strategy to mitigate resonances in offshore wind farms caused by the parasitic capacitance of submarine cables, which challenge system stability and grid code compliance. The proposed method emulates a virtual impedance damping the wide range of resonances that appear in offshore wind farms, depending on its configuration and number of turbines connected. Its effectiveness is evaluated for two modulation techniques: PWM and selective harmonic elimination PWM. PWM generates predictable harmonic content outside the resonance range, enabling robust damping of resonances. In contrast, selective harmonic elimination PWM¿though optimized to eliminate the harmonics in the resonance frequency range¿introduces distortion in this range due to modulation-control interactions in closed-loop operation. This distortion demands excessive corrective action from the AD, limiting its practicality. The strategy and its results are validated through simulation.Publication Open Access Passivity analysis in power electronic converters with SHE modulation(HAL, 2025-05-23) Ramos Arocena, Naroa; Pascual Iglesias, Iñigo; Gubía Villabona, Eugenio; López Taberna, Jesús; Samanes Pascual, Javier; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate PublikoaTo ensure the stability of modern power grids, particularly those dominated by power electronics, it is convenient for grid-connected converters to exhibit passivity across the entire frequency spectrum. Furthermore, it is interesting not only for the system to be passive, that is, for the converter system's resistance to be positive, but also for this resistance to have a high value, as it helps dampen potential grid resonances. This article presents a study of a grid-connected converter, achieving passivity and increasing the converter's resistance through control strategies. Given the growing use of Selective Harmonic Elimination (SHE) modulation techniques in high-power converters, the analysis will also focus on how to assess the passivity of a system employing these modulation techniques.