Comunicaciones y ponencias de congresos - Biltzarrak eta Argitalpenak

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Open Access
1-V 15-μW 130-nm CMOS super class AB OTA
(IEEE, 2020) López Martín, Antonio; Algueta-Miguel, Jose M.; Garde Luque, María Pilar; Carvajal, Ramón G.; Ramírez-Angulo, Jaime; Institute of Smart Cities - ISC
A super class AB recycling folded cascode amplifier in 130 nm CMOS is presented. It combines for the first time adaptive biasing of the differential input pair, nonlinear current mirrors with current starving and dynamic biasing of the cascode transistors in the output branch. Measurements using a ±0.5V supply show slew rate and gain bandwidth product improvement factors of 26 and 112 versus the conventional topology for the same bias currents, yielding the highest combined FoM to date.
Open Access
3D-RL MIMO capacity estimations under vegetation blockage
(IEEE, 2023-09-07) Rodríguez Corbo, Fidel Alejandro; Celaya Echarri, Mikel; Shubair, Raed M.; Falcone Lanas, Francisco; Azpilicueta Fernández de las Heras, Leyre; Institute of Smart Cities - ISC
Multiplexing gains are one of the many promises for increasing throughput in multiple-input-multiple-output (MIMO) systems. In this sense, a rich scattered environment may be beneficial for the multiplexing capabilities of the MIMO channel. However, mm Wave frequency bands tend to have less effective multipath contributions than sub-6 GHz bands. In this work, an in-deep analysis of the multiplexing capabilities in a mm Wave vehicular-to-infrastructure (V2I) channel is performed. Metrics that may impact the channel capacity like received power and angle-of-arrival (AoA) Spread are fully analyzed as well.
Open Access
A propósito de una cornucopia romana en mármol procedente de la antigua ciudad de Campo Real/Fillera (Sangüesa, Navarra)
(Gobierno de Navarra, 2011) Andreu Pintado, Javier; Zuazúa Wegener, Nicolás; Armendáriz Martija, Javier; Royo Plumed, Hernando; Ciencias Humanas y de la Educación; Giza eta Hezkuntza Zientziak
Se da a conocer un fragmento de escultura romana, tallada en mármol blanco de Proconnesos (isla de Mármara, Turquía), encontrada en el territorio de la ciutas vascona de nombre ignoto de Campo Real/Fillera (Sos del Rey Católico, Zaragoza), en término de Baratiñones (Sangüesa, Navarra). Representa una cornucopia de bulto redondo que como abstracción se relacionaba con la Abuntandita, la Pax, la Felicitas, la Concordia o la Spes. Como atributo de divinidades se asocia principalmente a Tychel/Fortuna, aunque también a los Lares.
Open Access
A-priori flow bandwidth estimates for dynamic bandwidth allocation in ISP access links
(2001) Aracil Rico, Javier; Morató Osés, Daniel; Automática y Computación; Automatika eta Konputazioa
In this paper we study a-priori bandwidth estimation algorithms for TCP flows. An RTT-based bandwidth allocator is proposed, which outperforms a broad class of peak-rate and static allocation flow switching solutions. Our findings suggest that a-priori bandwidth estimation (i.e, before the TCP data transfer phase takes place) is indeed feasible and serves to design simple, yet efficient, dynamic bandwidth allocation rules for ISP access links.
Open Access
About the intuitionistic fuzzy set generators
(Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1997) Bustince Sola, Humberto; Mohedano Salillas, Victoria; Automática y Computación; Automatika eta Konputazioa
In this paper form the definition of intuitionistic fuzzy sets we analyze the intuitionistic fuzzy generators and the complementation in these sets. We start by defining the intuitionistic fuzzy generators in order to then study the particular cases for which this definition coincides with the fuzzy complementation. Afterwards we analyze the existence of equilibrium points, dual points and we present characterization theorems of intuitionistic fuzzy generators. Lastly, we study a manner of constructing intuitionistic fuzzy sets and analyse the structure of the complementary of intuitionistic fuzzy sets built.
Open Access
Acceder a la universidad: una propuesta de intervención social con jóvenes en desventaja social
(Revista Alimara, 2023) Peña Gutiérrez, Alejandro; Pérez Eransus, Begoña; Martínez Virto, Lucía; Sociología y Trabajo Social; Soziologia eta Gizarte Lana
La literatura académica sostiene que no alcanzar estudios superiores es un factor de exclusión y vulnerabilidad. Igualmente, plantea que la juventud de entornos desfavorecidos presenta mayores tasas de abandono educativo y sufre más dificultades de promoción educativa, situándose en mayor desventaja social para acceder, mantenerse y superar los estudios superiores. Por ello, las acciones orientadas a promover que las y los jóvenes de entornos vulnerables accedan y culminen sus estudios universitarios, son una estrategia de intervención clave para frenar la reproducción social de la pobreza y la exclusión. En este marco, la Universidad Pública de Navarra y el Departamento de Políticas Migratorias y Justicia del Gobierno de Navarra han desarrollado una estrategia de intervención para promover el acceso a la universidad de jóvenes en situación de desventaja.
Open Access
Actitudes políticas y resultados electorales de Navarra desde 1977
(FEDHAV, 2010) Ayerdi Echeverri, Peio; Sociología; Soziologia
El objetivo de este trabajo es presentar información sociológica sobre la evolu- ción de la vida política navarra en las últimas décadas, así como de sus espacios sociopolíticos y de su sistema de partidos. En primer lugar se considerarán las elecciones generales y a continuación se considerarán más detenidamente las elecciones propiamente navarras o lo que es lo mismo, las elecciones al Parlamento de Navarra. A continuación se describirá la institucionalización de la vida política navarra en su Parlamento y Gobierno. Seguidamente entraremos en el análisis de la geografía electoral de las últimas elecciones de 2007. Más tarde analizaremos las bases sociales de los diferentes electorados como, la Marca de navarridad, la religiosidad, los grupos de edad, la clase social, la autoubicación ideológica y por último el sentimiento identitario. Para terminar se interpretan diversos sondeos y se adelantan algunas predicciones para las elecciones del 2011.
Open Access
Active control for medium-frequency transformers flux-balancing in a novel three-phase topology for cascaded conversion structures
(IEEE, 2020) Lumbreras Magallón, David; Barrios Rípodas, Ernesto; Navarrete, Manuel; Balda Belzunegui, Julián; González Senosiain, Roberto; Sanchis Gúrpide, Pablo; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Efficiency and power density are important parameters in the design of power electronics converters. In many applications, low-frequency transformers are being substituted for medium-frequency and high-frequency transformers in order to reduce the volume and therefore the cost of the transformer. However, preventing their saturation is a complex task. This paper studies the medium-frequency transformers' flux balancing in a novel three-phase topology for cascaded conversion structures.Based on the modulation technique of the converter, a method to directly measure the magnetizing current of the medium-frequency transformers is proposed in this paper. A control loop to regulate the dc value of the magnetizing current is also designed and developed. Simulation results validate the correct operation of the control loop, which prevents the transformer saturation.
Open Access
Active damping based on the capacitor voltage positive-feedback for grid-connected power converters with LCL filter
(IEEE, 2019) Samanes Pascual, Javier; Gubía Villabona, Eugenio; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
The capacitor voltage positive-feedback is a widely extended active damping strategy. It can effectively damp the LCL output filter resonant poles for low ratios of resonance to sampling frequencies. However, the existing delays in the control loop limit the applicability of the capacitor-voltage positive-feedback. For high ratios of resonance to sampling frequencies, it becomes ineffective and can even destabilize the system. This limitation is overcome in this paper by adjusting the delay in the feedback path. With the delay adjustment, a robust damping can be achieved if the delays are properly considered, including the filters, and the grid impedance variations are taken into account. Simulation results validate the proposed active damping strategy.
Open Access
Actores sociales y conflictos en las áreas de montaña en torno al desarrollo
(2004) Sanz Tolosana, Elvira; Sociología; Soziologia
Actualmente, el proyecto de creación de una estación de esquí en Larra (Roncal) ha favorecido un debate sobre su orientación futura y las estrategias para su revitalización. Un debate donde confluyen distintos actores locales (Ayuntamientos, Junta de Valle, Plataforma Zain Dezagun Larra, monitores de esquí, asociaciones de empresarios turísticos, etc.) y extralocales (Gobierno de Navarra, partidos políticos, montañeros, organizaciones ecologistas, colegio de biólogos,...), y consecuentemente distintas concepciones de desarrollo. Un interés y una implicación de la sociedad navarra en general, que pone de manifiesto cómo la ruralidad, y especialmente, las áreas de montaña, se erigen como los guardianes de lo realmente auténtico e identitario, en definitiva, el gran peso simbólico del Valle de Roncal en la identidad navarra.
Open Access
Actores sociales, oportunidades e incertidumbres del “estado local"
(2004) Oliva Serrano, Jesús; Sociología; Soziologia
Las transformaciones que experimentan las sociedades del cambio de siglo han abierto el mundo rural a tendencias, relaciones, oportunidades e incertidumbres impredecibles hace apenas unas décadas. Por un lado, los entornos locales se han convertido progresivamente en escenarios donde confluyen las nuevas tendencias residenciales, los movimientos migratorios, las demandas turísticas, de conservación y de localización productiva, etc. De esta forma, no solo pueden albergan en muchas ocasiones un variado elenco de actores sociales sino que se conforman progresivamente como una realidad compleja sobre la cual son llamados a intervenir cada vez de forma más polivalente los poderes locales pues estos procesos otorgan a los mismos un papel estratégico en la organización del bienestar social, la mediación para los cambiantes y necesarios consensos locales así como la interlocución con los otros niveles de las administraciones públicas. Y si bien la revolución de los medios de comunicación permite hoy desarrollar diferentes fórmulas de democracia participativa en estos contextos, también las consecuencias derivadas de la tensión que el nuevo espacio de los flujos identificado por Castells (1995) ejerce sobre el viejo espacio de los lugares, someten el futuro de numerosas localidades a una incertidumbre multiplicada. Se reflexiona en este trabajo sobre los efectos, posibilidades y peligros que conllevan estos nuevos procesos, prestando una especial atención a la ruralidad Navarra.
Open Access
Acumulación/movilización de reservas grasas: especie caprina versus especie ovina
(Universidad Cardenal Herrera-CEU. Fundación Universitaria San Pablo-CEU, 2002) Mendizábal Aizpuru, José Antonio; Delfa, R.; Eguinoa Ancho, Paola; Arana Navarro, Ana; González, C.; Alzón, M.; Purroy Unanua, Antonio; Producción Agraria; Nekazaritza Ekoizpena
En 20 cabras de raza Blanca Celtibérica (PV: 55,8±12,95Kg.) con notas de condición corporal esternal comprendidas entre 1,5 y 4,5 (3±1,0; escala 0-5) y 20 ovejas de raza Rasa Aragonesa (PV: 55,5±12,46Kg.) con notas de condición corporal lumbar comprendidas entre 1,5 y 4,5 (3±1,0; escala 0-5), todas ellas adultas, secas y vacías, se ha estudiado la variación de la cantidad de grasa en los depósitos grasos omental (OM), mesentérico (MES), pelvicorrenal (PR), subcutáneo (SC) e intermuscular (IM) con la nota de condición corporal (mee). Los resultados obtenidos muestran que, en general, las cabras de raza Blanca Celtibérica presentaban mayor cantidad de grasa que las ovejas de raza Rasa Aragonesa (11.129 frente a 8.450 gr. de grasa total) para una nCC media de 3 y un PV de 56 Kg. en ambas especies. Unicamente, en el depósito PR las ovejas presentaron mayor cantidad de grasa que las cabras (1.878 vs 1636 g). En la especie caprina, la mayor acumulación/movilización de grasa por unidad de variación de la nCC se produjo en el depósito OM (1938 g), mientras que en la especie ovina tuvo lugar en el depósito PR (1219 g). No obstante, si comparamos la variación relativa de cada depósito graso (proporcional al peso medio de cada depósito) ésta tuvo lugar en ambas especies en el subcutáneo, con una variación del 72,5 y 65,3% en las cabras y ovejas, respectivamente.
Open Access
Additional feature layers from ordered aggregations for deep neural networks
(IEEE, 2020) Domínguez Catena, Iris; Paternain Dallo, Daniel; Galar Idoate, Mikel; Institute of Smart Cities - ISC; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
In the last years we have seen huge advancements in the area of Machine Learning, specially with the use of Deep Neural Networks. One of the most relevant examples is in image classification, where convolutional neural networks have shown to be a vital tool, hard to replace with any other techniques. Although aggregation functions, such as OWA operators, have been previously used on top of neural networks, usually to aggregate the outputs of different networks or systems (ensembles), in this paper we propose and explore a new way of using OWA aggregations in deep learning. We implement OWA aggregations as a new layer inside a convolutional neural network. These layers are used to learn additional order-based information from the feature maps of a certain layer, and then the newly generated information is used as a complement input for the following layers. We carry out several tests introducing the new layer in a VGG13-based reference network and show that this layer introduces new knowledge into the network without substantially increasing training times.
Open Access
Additively generated (a,b)-implication functions*
(IEEE, 2023) Santos, Helida; Pereira Dimuro, Graçaliz; Bedregal, Benjamin; Paiva, Rui; Lucca, Giancarlo; Moura, Bruno; Cruz, Anderson; Bustince Sola, Humberto; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
Some problems involving classification through neural networks are known to use inputs out of the scope of the unit interval. Therefore, defining operations on arbitrary closed real intervals may be an interesting strategy to tackle this issue and enhance those application environments. In this paper we follow the ideas already discussed in the literature regarding (a,b)-fusion functions, and (a,b)-negations, to provide a new way to construct implication functions. The main idea is to construct an operator using additively generated functions that preserve the properties required by implication functions.
Open Access
Addressing the issue of trust in elementary teachers' maths-specific education: ANFoMAM project
(Charles University (Chequia), 2019) Celi, Valentina; Cogolludo, José Ignacio; Gil Clemente, Elena; Lizasoain Iriso, María Inmaculada; Millán Gasca, Ana; Moler Cuiral, José Antonio; Regoliosi, Luigi; Estadística, Informática y Matemáticas; Estatistika, Informatika eta Matematika
To improve primary school teachers' maths-specific education at university, our project will develop a series of workshops, as ready-to-use instruments, which closely consider children's way of learning and their relationship with mathematics. Thus, the interest of participants in children is exploited in sessions which take into account both their professional work as teachers and their own childhood experiences. The aim is to help participants to evolve in the key aspect of trust. The paper describes the objectives and first results of the ANFoMAM project, supported by the Erasmus Plus Programme in the area of strategic partnerships for innovation in higher education in Europe.
Open Access
Adjusting fuzzy automata for string similarity measuring
(EUSFLAT, 2001) Astrain Escola, José Javier; Villadangos Alonso, Jesús; González de Mendívil Moreno, José Ramón; Garitagoitia Padrones, José Ramón; Fariña Figueredo, Federico; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza; Automática y Computación; Automatika eta Konputazioa
In this paper, we introduce a fuzzy automaton for computing the similarity between pairs of strings and a genetic method for adjusting its parameters. The fuzzy automaton models the edit operations needed to transform any string into another one. The selection of appropriate fuzzy operations and fuzzy membership values for the transitions leads to improve the system performance for a particular application.
Open Access
Adjustment of the fuzzy logic controller parameters of the energy management strategy of a grid-tied domestic electro-thermal microgrid using the Cuckoo search algorithm
(IEEE, 2019) Arcos Avilés, Diego; García Gutiérrez, Gabriel; Guinjoan Gispert, Francesc; Pascual Miqueleiz, Julio María; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
During the last century, population growth, together with economic development, has considerably increased the energy demand and, although renewable energies are becoming an alternative, still total energy supply is mainly non-renewable, causing well-known negative effects such as pollution and global warming. On the other hand, technological advances have allowed the development of increasingly efficient distributed generation systems and the emergence of microgrids, whose studies have been focused on architecture, elements, and objectives of the associated energy management strategies. In this regard, energy management strategies based on a Fuzzy Logic controller have been developed for electro-thermal microgrids where parameter optimization has been carried out through heuristic procedures of trial and error with acceptable results but involving a high computational cost. To solve the aforementioned drawbacks, in the present work the use of Cuckoo Search optimization nature-inspired algorithm that allows the adjustment of Fuzzy Logic controller parameters and ensures a higher quality of energy management is proposed. Obtained results show encouraging outcomes for the use of these meta-heuristic optimization algorithms.
Open Access
Advances in sensors using lossy mode resonances
(SPIE, 2023-11-27) Matías Maestro, Ignacio; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Lossy mode resonance (LMR) is a phenomenon that is observed in the optical spectrum when a mode that progresses through a waveguide starts to be guided in a thin film deposited on this waveguide under certain conditions, mainly related to materials and angles of incidence. An important property that LMRs have is that they can be guided into the thin film with both magnetic (TM) and electrical (TE) polarized light, unlike the other two main types of optical resonances with the same modus operandi that complete this trilogy, surface plasmon resonances (SPRs) and surface exciton plasmon resonances (SEPR). Regarding the potential materials that make up thin films, they include dielectrics suchs as metal oxides such as titanium dioxide (TiO2), zinc oxide (ZnO), tin oxide (SnO2) or polymers. In all cases it must be fulfilled that the real part of the refractive index must be greater than its imaginary part, unlike also the SPR and SEPR. As for the angles of incidence, they must be close to 90º, which explains the success of deposition of thin films around an optical fiber to obtain sensors based on LMR, although interesting results have recently been obtained using planar waveguides. This work will present the main milestones obtained during more than a decade using LMR-based sensors for the detection of multiple parameters. Among these interesting aspects, we can mention the sensitivity records achieved, hybridization with other sensing technologies or the possibility of multiplexing multiple sensors on the same substrate, just to mention a few.
Open Access
Agent-based simulation improves e-grocery deliveries using horizontal cooperation
(IEEE, 2020) Serrano Hernández, Adrián; Faulín Fajardo, Javier; Torre Martínez, Rocío de la; Cadarso, Luis; Estatistika, Informatika eta Matematika; Enpresen Kudeaketa; Institute of Smart Cities - ISC; Institute for Advanced Research in Business and Economics - INARBE; Estadística, Informática y Matemáticas; Gestión de Empresas
E-commerce has increased tremendously in recent decades because of improvements in the information and telecommunications technology along with changes in societal lifestyles. More recently, e-grocery (groceries purchased online) including fresh vegetables and fruit, is gaining importance as the most-efficient delivery system in terms of cost and time. In this respect, we evaluate the effect of cooperation-based policies on service quality among different supermarkets in Pamplona, Spain. Concerning the methodology, we deploy, firstly, a detailed survey in Pamplona in order to model e-grocery demand patterns. Secondly, we develop an agent-based simulation model for generating scenarios in cooperative and non-cooperative settings, considering the real data obtained from the survey analysis. Thus, a Vehicle Routing Problem is dynamically generated and solved within the simulation framework using a biased-randomization algorithm. Finally, the results show significant reductions in lead times and better customer satisfaction when employing horizontal cooperation in e-grocery distribution.
Open Access
Aggregation functions based on the Choquet integral applied to image resizing
(Atlantis Press, 2019) Bueno, Jéssica C. S.; Dias, Camila A.; Pereira Dimuro, Graçaliz; Santos, Helida; Bustince Sola, Humberto; Estatistika, Informatika eta Matematika; Institute of Smart Cities - ISC; Estadística, Informática y Matemáticas
The rising volume of data and its high complexity has brought the need of developing increasingly efficient knowledge extraction techniques, which demands efficiency both in computational cost and in accuracy. Most of problems that are handled by these techniques has complex information to be identified. So, machine learning methods are frequently used, where a variety of functions can be applied in the different steps that are employed in their architecture. One of them is the use of aggregation functions aiming at resizing images. In this context, we introduce a study of aggregation functions based on the Choquet integral, whose main characteristic in comparison with other aggregation functions is that it considers, through fuzzy measure, the interaction between the elements to be aggregated. Thus, our main goal is to present an evaluation study of the performance of the standard Choquet integral the and copula-based generalization of the Choquet integral in relation to the maximum and mean functions, looking for results that may be better than the aggregation functions commonly applied. The results of such comparisons are promising, when evaluated through image quality metrics.