Person: Valencia Leoz, Ana
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Valencia Leoz
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Ana
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Publication Open Access AplicaciĆ³n en MATLAB para el anĆ”lisis de la respuesta en bajas frecuencias de recintos pequeƱos de tipologĆa rectangular(2017) Valencia Leoz, Ana; San MartĆn Murugarren, Ricardo; Escuela TĆ©cnica Superior de Ingenieros Industriales y de TelecomunicaciĆ³n; Telekomunikazio eta Industria Ingeniarien Goi Mailako Eskola TeknikoaEn el presente proyecto se analizan los fenĆ³menos de interferencia que aparecen en recintos de dimensiones pequeƱas a frecuencias inferiores a la de Schroeder y que provocan una coloraciĆ³n dependiente de la posiciĆ³n del receptor. Para ello se desarrollan dos aplicaciones de predicciĆ³n en Matlab basadas en condiciones de frontera rĆgida: la primera predice NPS de manera teĆ³rica, empleando como excitaciĆ³n una fuente puntual; la segunda los predice a partir de un conjunto de medidas realizadas en tres ejes de la sala, tomando como origen de coordenadas una de las esquinas. Las aplicaciones se evalĆŗan en una sala de ensayo comparando los resultados de las predicciones con medidas reales en cuatro configuraciones de sala diferentes. Se observa cĆ³mo conforme la realidad se aleja de la hipĆ³tesis de paredes rĆgidas aumenta la sensibilidad de las herramientas diseƱadas, lo que limita su capacidad de predecir niveles de presiĆ³n en situaciones reales.Publication Open Access Influence of recording technology on the determination of binaural psychoacoustic indicators in soundscape investigations(Institute of Noise Control Engineering, 2019) San MartĆn Murugarren, Ricardo; Arana Burgui, Miguel; Ezcurra Guisasola, MarĆa Amaya; Valencia Leoz, Ana; Ciencias; ZientziakThe evaluation of soundscapes is mainly carried out through field surveys, using soundwalking methodologies. Through rating scales and annotation of comments, the experiences and expectations of the participants are collected. Acoustic and psychoacoustic indicators are also reported to achieve a complete description of the acoustic environment. Binaural measurement systems should be used for registration in order to consider the way in which humans perceive the acoustic environment. Artificial heads or in-ear binaural microphones are the usual devices for this purpose. Further recording technology such as sound field microphones or microphone arrays are also used in soundscape investigations. These methods can provide a higher level of immersion in a later reproduction of the recorded soundscape through multi-channel setups. However, in contrast to direct binaural recordings, the determination of binaural psychoacoustic indicators requires to perform binaural synthesis by means of Head-Related Transfer Functions and signal processing. In this communication, the influence of different recording devices on obtaining psychoacoustic indicators such as binaural loudness and sharpness is analysed.Publication Open Access Experimental evaluation of distortion in amplitude modulation techniques for parametric loudspeakers(MDPI, 2020) San MartĆn Murugarren, Ricardo; Tello Santacana, Pablo; Valencia Leoz, Ana; Marzo PĆ©rez, Asier; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC; Gobierno de Navarra / Nafarroako GobernuaParametric loudspeakers can generate a highly directional beam of sound, having applications in targeted audio delivery. Audible sound modulated into an ultrasonic carrier will get self-demodulated along the highly directive beam due to the non-linearity of air. This non-linear demodularization should be compensated to reduce audio distortion, different amplitude modulation techniques have been developed during the last years. However, some studies are only theoretical whereas others do not analyze the audio distortion in depth. Here, we present a detailed experimental evaluation of the frequency response, harmonic distortion and intermodulation distortion for various amplitude modulation techniques applied with different indices of modulation. We used a simple method to measure the audible signal that prevents the saturation of the microphones when the high levels of the ultrasonic carrier are present. This work could be useful for selecting predistortion techniques and indices of modulation for regular parametric arrays.Publication Open Access Assessment of flesh browning diversity in apple germplasm collections phenotyped by image analysis(ISHS, 2023) Miranda JimĆ©nez, Carlos; Irisarri, P.; Arellano Zapatero, Julia; Bielsa, F. J.; Valencia Leoz, Ana; Urrestarazu Vidart, Jorge; Pina, Ana; Santesteban GarcĆa, Gonzaga; Castel, L.; Errea, Pilar; AgronomĆa, BiotecnologĆa y AlimentaciĆ³n; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMABEnzymatic flesh browning (EB) is one of the major problems affecting the quality and limiting the shelf life of minimally processed fruit. Traditionally, EB has been measured objectively using colourimeters. However, colourimeters are not suitable for phenotyping large quantities of fruit samples as they measure just one small area of a sample at a time, which hampers the acquisition of representative measurements and renders them time-consuming and costly. Previous research has shown that image analysis of digital photographs could be a viable alternative to obtain colour information of the entire surface of samples for large scale phenotyping, but to date there are no references for its practical application. The aim of this work was to assess the diversity in EB in a large set of cultivars phenotyped using digital photographs and a high-throughput analytical system based on image analysis developed by our team. A set of 143 cultivars from 104 genotypes, including modern references (16 cultivars) and traditional Spanish cultivars from UPNA (67 cultivars) and CITA (60 cultivars) germplasm collections was analysed in 2020 and 2021. The traditional cultivars were part of the core collection, which optimizes the representativeness of the genetic variation of apples preserved in Spanish collections. EB was evaluated in 10 fruits per cultivar and photographed at regular intervals from just after cutting to one hour later. A wide range of EB intensities was observed, with up to 20-fold differences between cultivars, which could be classified into five levels using two indices. The time at which EB was evaluated (30 or 60 min after slicing) had little influence on the classification. Traditional cultivars with low or very low EB were found to be comparable to those of references with less EB. The results show the potential of traditional germplasm to diversify the varietal offer and introduce new traits in apple breeding.Publication Open Access An efficient algorithm for the evaluation of tonality and the determination of the tonal frequency according to IEC 61400-11(Institute of Noise Control Engineering, 2019) Arana Burgui, Miguel; San MartĆn Murugarren, Ricardo; Ezcurra Guisasola, MarĆa Amaya; Valencia Leoz, Ana; Llorente, Elena; Ciencias; ZientziakThe terms of tonality and tonal audibility of the noise emitted by wind turbines are defined and described in the standard IEC 61400-11. The procedure for tonality assessment at different wind speeds based on the narrowband analysis is explained in section 9.5 of the standard. After sorting spectra into wind speed bins, the overall tonal audibility is determined if at least six of ten of the narrowband spectra have an identified tone with the same origin. The standard describes a procedure for tonality assessment by means of a flowchart. Tones of the same origin are treated and reported as one tone. However, the standard does not specify the final value of the frequency of the tone. An efficient algorithm has been developed to evaluate the tonality of the noise emitted by wind turbines. Likewise, different alternatives to specify the final frequency of the tone are discussed, based either on their frequency of appearance in the total of the number of measurements or on the tone levels produced by such frequency.