Optimal Representation of Anuran Call Spectrum in Environmental Monitoring Systems Using Wireless Sensor Networks

The analysis and classification of the sounds produced by certain animal species, notably anurans, have revealed these amphibians to be a potentially strong indicator of temperature fluctuations and therefore of the existence of climate change. Environmental monitoring systems using Wireless Sensor Networks are therefore of interest to obtain indicators of global warming. For the automatic classification of the sounds recorded on such systems, the proper representation of the sound spectrum is essential since it contains the information required for cataloguing anuran calls. The present paper focuses on this process of feature extraction by exploring three alternatives: the standardized MPEG-7, the Filter Bank Energy (FBE), and the Mel Frequency Cepstral Coefficients (MFCC). Moreover, various values for every option in the extraction of spectrum features have been considered. Throughout the paper, it is shown that representing the frame spectrum with pure FBE offers slightly worse results than using the MPEG-7 features. This performance can easily be increased, however, by rescaling the FBE in a double dimension: vertically, by taking the logarithm of the energies; and, horizontally, by applying mel scaling in the filter banks. On the other hand, representing the spectrum in the cepstral domain, as in MFCC, has shown additional marginal improvements in classification performance.University of Seville: Telefónica Chair "Intelligence Networks

Numerical analysis for a chemotaxis-navier-stokes system

In this paper we develop a numerical scheme for approximating a d-dimensional chemotaxis- Navier–Stokes system, d= 2, 3, modeling cellular swimming in incompressible fluids. This model describes the chemotaxis-fluid interaction in cases where the chemical signal is consumed with a rate proportional to the amount of organisms. We construct numerical approximations based on the Finite Element method and analyze optimal error estimates and convergence towards regular solutions. In order to construct the numerical scheme, we use a splitting technique to deal with the chemo-attraction term in the cell-density equation, leading to introduce a new variable given by the gradient of the chemical concentration. Having the equivalent model, we consider a fully discrete Finite Element approximation which is well-posed and mass-conservative. We obtain uniform estimates and analyze the convergence of the scheme. Finally, we present some numerical simulations to verify the good behavior of our scheme, as well as to check numerically the optimal error estimates proved in our theoretical analysis

Evaluation of the Processing Times in Anuran Sound Classification

Nowadays, sound classification applications are becoming more common in the Wireless Acoustic Sensor Networks (WASN) scope. However, these architectures require special considerations, like looking for abalance between transmitted data and local processing.This article proposes an audio processing and classification scheme, focusing on WASN architectures.This article also analyzes in detail the time efficiency of the different stages involved (from acquisition to classification). This study provides useful information which makes it possible to choose the best tradeoff between processing time and classification result accuracy. This approach has been evaluated on a wide set of anurans songs registered in their own habitat. Among the conclusions of this work, there is an emphasis on the disparity in the classification and feature extraction and construction times for the different studied techniques,all of them notably depending on the over all feature number used.Consejería de Innovación, Ciencia y Empresa, Junta de Andalucía, Spain, through the Excellence Project eSAPIENS (Ref. TIC-5705

Representación óptima del espectro de llamadas de anuros en sistemas de control ambiental utilizando redes de sensores inalámbricos

El análisis y la clasificación de los sonidos producidos por determinadas especies animales, en particular los anuros, han revelado que son un potente indicador de la existencia del cambio climático. Es por lo que los sistemas de monitorización ambiental que utilizan redes de sensores inalámbricos son de gran interés para obtener indicadores del calentamiento global. El presente documento se centra en este proceso de extracción de características explorando tres alternativas: el MPEG- 7 estandarizado, los Filter Bank Energy (Energía de Bancos de Filtros, FBE) y los Mel Frequency Cepstral Coefficients (Coeficientes Cepstrales de Frecuencia de Mel, MFCC). Además, se consideran diferentes valores para cada opción en la extracción de las características del espectro.The analysis and classification of the sounds produced by certain animal species, in particular anurans, have revealed that they are a powerful indicator of the existence of climate change. Environmental monitoring systems using wireless sensor networks are of great interest for global warming indicators. This paper focuses on this feature extraction process by exploring three alternatives: the standardised MPEG-7, Filter Bank Energy (FBE) and Mel Frequency Cepstral Coefficients (MFCC). In addition, different values are considered for each option in the extraction of spectrum characteristics

Ingeniería de características para la clasificación de señales sonoras

Muchos autores han demostrado que el canto de anuros puede ser un indicador del cambio climático. Por esta razón, la clasificación del sonido del canto de anuros se ha convertido en un tema importante para biólogos y otros científicos del clima. A lo largo de este artículo se describirá la investigación que se llevará a cabo para encontrar el mejor camino de realizar una clasificación automática de los cantos de anuros.Several authors have shown that the sounds of anurans can be used as an indicator of climate change. For this purpose anuran sound automatic classification has become an important issue for biologists and other climate scientists. In this paper, we will describe the research to find the best way to perform an automatic classification of anurans sounds.Plan Propio de la Universidad de Sevilla Proyecto: 2017/0000096

Baropodometric association of the first metatarsal bone in medial tibial stress syndrome

[Resumen] Objetivos: El síndrome de estrés tibial medial (SETM) es una lesión de sobreuso por estrés mecánico, que se localiza por lo general en el borde postero-medial de la tibia. El objetivo de este estudio es cuantificar la diferencia baropodométrica existente en la primera cabeza metatarsal entre dos grupos. Métodos: Se analizaron las huellas de 30 participantes, de los cuales 15 padecían SETM y 15 controles. Se trata de un estudio observacional en el que se obtuvieron las huellas baropodométricas de los participantes, caminando sobre una plataforma de presiones. Se cuantificó la presión plantar media y la integral presión/tiempo que estaba recibiendo cada paciente en la primera cabeza metatarsal. Realizamos la prueba t-student para muestras independientes con el objetivo de definir las diferencias. Resultados: Los resultados de la variable presión plantar media muestran diferencias estadísticamente significativas entre los 2 grupos (p=0,001 para pie izquierdo y p=0,001 para pie derecho). Por el contrario no se observaron diferencias estadísticamente significativas para la variable integral presión/tiempo en ambos grupos (p=0,327 para pie izquierdo y p=0,300 para pie derecho). Conclusiones: Según nuestro estudio, los resultados obtenidos concluyen que el SETM se ocasiona con mayor frecuencia en personas con una disminución significativa de la presión plantar en la cabeza del primer metatarsiano medida en plataforma baropodométrica. Consideramos que son necesarios más estudios que evidencien esta relación biomecánica mediante plantillas instrument[Abstract] Objectives: Medial tibial stress syndrome (MTSS) is a mechanical stress overuse lesion, which is usually located at the post-medial border of the tibia. This study aims to quantify the baropodometric difference in the first metatarsal head between two groups. Methods: For the study 30 patient footprints were analyzed. Among them, half were affected by MTSS and the other half were controls. The baropodometric footprint samples were obtained by walking barefooted over a platform. While the patients were walking the average plantar pressure and the integral ratio pressure/time was quantified. The T-student test was performed in independent samples in order to define the differences. Results: The average plantar pressure results show statistically significant differences amongst the 2 groups (p=0.001 for the left foot and p=0.001 for the right foot). On the other hand, there were not any significant differences for the integral pressure/time variable in both groups (p=0.327 for the left foot and p=0.300 for the right foot). Conclusion: By having done this study, we can affirm that the MTSS is more frequent in persons with a significant plantar pressure decrease in the first metatarsal head measured in the baropodometric platform. We consider the need for further studies that prove this biomechanical connection through instrumented insoles

Impact of climate change on berthing areas in ports of the Balearic Islands: adaptation measures

Climate change generates impacts on coastal areas due to sea-level rise and potential modifications in wave and storm surge patterns. Since harbours are located in littoral areas, they will experience different impacts associated to such processes. In this paper, the effects of climate change on port berthing areas in terms of operability are quantified. The study is focused on the ports of the Balearic Islands (Western Mediterranean Sea) and analyses the loss of operability due to the reduction of freeboard in berthing structures and the potential variation in agitation within these harbours during the 21st century, considering two different climate scenarios (RCP4.5 and RCP8.5) and two-time horizons (2045 and 2100). In addition, adaptation measures to address such impacts are proposed and their cost estimated. The results indicate that climate change will not generate significant changes in wave agitation due to negligible variations in wave patterns under future scenarios. On the contrary, sea-level rise will cause huge increases of inoperability for berthing structures due to insufficient freeboard: 10.5% under RCP4.5 or 20.5% under RCP8.5 in 2045, increasing to 57.1% (RCP4.5) and even 83.2% (RCP8.5) in 2100.This study was supported by PIMA ADAPTA-Balears Project funded by Conselleria de Transició Energética, Sectors Productius i Memòria Democràtica and Conselleria de Mobilitat i Habitatge, Govern Balear, and by the project PLEC2021-007810 funded by MCIN/AEI/10.13039/501100011033 and by the European Union “Next Generation EU”/PRTR”.Peer ReviewedPostprint (published version

Aspectos de la simetría de las transformaciones integrales en la caracterización de sonidos

La aplicación de técnicas de aprendizaje automático a señales de sonido requiere la caracterización previa de dichas señales. A menudo, la descripción del espectro sonoro se realiza utilizando coeficientes cepstrales. En este trabajo, se compara el desempeño en la obtención de coeficientes cepstrales mediante dos transformaciones integrales, la Transformación discreta de Fourier (DFT) y la Transformación discreta de coseno (DCT). Se puede demostrar que DCT supera a DFT en la tarea de representar los espectros de sonido. Esta mejora se debe a la simetría del espectro y no a ninguna ventaja intrínseca de DCT. Además, las características de MFCC obtenidas con DCT están notablemente menos correlacionadas que las obtenidas con DFT, lo que hará que las funciones MFCC basadas en DCT sean más potentes en algoritmos de clasificación posteriores