Sensor Array Optimization for Multiple Harmonic Sound Source Separation and DOA

INTRODUCTION In the last years a lot of researches about source separation have been realized, like extraction of a signal of interest (vocal recognition application), identification of which source gives which sound (motor engine applications) or noise source characterization (environmental application). Most of these techniques for sound source estimation use the signal-subspace approach, where the number of emitting sources is determined by the multiplicity of the lowest eigenvalue of the correlation matrix. The problems arise when the number of microphones is equal to the number of sources radiating, hence the noise subspace could not exist. This Master Thesis investigates how to realize a Goniometer Antenna to record communications, as well as the implementation of an algorithm to optimize the location of the sensors with the intend of separating the different sound sources in the at-worst case(number of sources equal number of sensors). It has been achieve using the eigenvalues of the correlation matrix of the received signals and the delay between microphones. Finally, measurements in the anechoic chamber verified the proposed approach. METHODS An acoustic goniometer is a system that measures the angle between a source and a receptor using the phase delay, thereby obtaining the source direction. The design dwell on two sensors (microphones) collocated in the 2D space in a concrete geometry. The implementation of each algorithm was done in Matlab based on two parts: the time delay estimation used in source localization by computing the azimuth in [2], and also an adaptation of the MPE block carried out in [4]. Likewise different methods based on the properties of the correlation matrix have been studied for delay estimating like in [3]. Apart from that, in [1] is explored the relation between sensor array geometry and eigenvalues to obtain the optimal sound sources separation and detection. This theory has been put into practice in programming in Matlab: minimization of the distance between microphones such that accomplish the condition of sources separation or sources detection. The optimization procedure has been done using two different SQP Methods: Active Set and Interior Point. Moreover, an optimization approach is presented for a system composed by two sensors and three sound sources. Several options based on mathematical theory has been considered for solving the problem. Eventually, taking advantage of the procedure followed in [1] and combined with the circumcenter calculation, the optimal distance for the microphones can be found. RESULTS Afterwards all this work, different simulations with the code in Matlab were tested reaching successful results. Then, a process of validation is required in the anechoic chamber for more realistic measurements. CONCLUSIONS In conclusion is demonstrated by theoretical calculation at first and then by experimental measurements that the optimal array geometry could help to improve the sound source separation approach. Forthcoming works will consist in extending this work for larger bandwidth and much more sound sources. Also, taking into consideration a more realistic model with reflections, interfering signals or noise corrupted

Un análisis descriptivo de la sociedad y economía del municipio de Morón de la Frontera

Morón de la Frontera es un municipio de la Sierra Sur de la provincia de Sevilla con una población próxima a los 28.000 habitantes, algo aislada en cuanto a infraestructuras terrestres, y con sector agrícola y de transformación de peso importante en su economía. Así, empresas muy conocidas de dicho sector se encuentra radicadas en el municipio. Ello no impide que haya altas tasas de desempleoUniversidad de Sevilla. Grado en Finanzas y Contabilida

Post-error response inhibition in high math-anxious individuals: Evidence from a multi-digit addition task

The aim of the study was to investigate how high math-anxious (HMA) individuals react to errors in an arithmetic task. Twenty HMA and 19 low math-anxious (LMA) individuals were presented with a multi-digit addition verification task and were given response feedback. Post-error adjustment measures (response time and accuracy) were analyzed in order to study differences between groups when faced with errors in an arithmetical task. Results showed that both HMA and LMA individuals were slower to respond following an error than following a correct answer. However, post-error accuracy effects emerged only for the HMA group, showing that they were also less accurate after having committed an error than after giving the right answer. Importantly, these differences were observed only when individuals needed to repeat the same response given in the previous trial. These results suggest that, for HMA individuals, errors caused reactive inhibition of the erroneous response, facilitating performance if the next problem required the alternative response but hampering it if the response was the same. This stronger reaction to errors could be a factor contributing to the difficulties that HMA individuals experience in learning math and doing math tasks

Effect of Location, Clone, and Measurement Season on the Propagation Velocity of Poplar Trees Using the Akaike Information Criterion for Arrival Time Determination

The purchase price of any forest plantation depends on the quality of its raw wood, and specifically, variables such as density, orientation of the fibers, bending strength, and bending MoE (Modulus of Elasticity). The elastic waves propagation velocity has become one of the most popular parameters to evaluate the wood in standing trees. This study had two objectives: (1) Show how this velocity is clearly affected by the clone, the location of the crop, and the measurement season of poplar crops; and (2) apply the Akaike information criterion to determinate the arrival time of the waves, on the basis of the entropy of the signals recorded by the piezoelectric sensors placed on the trunk of the tree.This work has been possible due to the financial support of the COMPOP_Timber project “Desarrollo de productos de ingeniería elaborados a base de tablones y chapas de chopo con inserciones de material compuesto para su uso en construcción”, BIA2017-82650-R. The authors thank to Antonio Aguilar and Chihab Abarkane, for his help during measurements in field, and Esther Merlo from MADERAS PLUS, for the analysis of results and methods

Experimental Comparison of Different Carbon Fiber Composites in Reinforcement Layouts for Wooden Beams of Historical Buildings

The authors also gratefully acknowledge the important contribution of lab technician David Jiménez.This paper offers a detailed, quantitative and exhaustive experimental comparison in terms of mechanical properties of three different layouts of carbon composite materials (CFRP) used to strengthen existing old timber beams highly affected by diverse natural defects and biological attacks, testing the use of pultruded laminate attached on the tension side of the element (LR), CFRP fabrics totally U-shape wrapping the timber element (UR), and the combined use of both reinforcement solutions (UR-P). Moreover, unidirectional and bidirectional fabrics were considered and compared. Timber elements used for the experimental program were extracted from a recent rehabilitation of the roof of the current Faculty of Law building, University of Granada (Spain), catalogued as a historical edifice. Experimental results from bending tests show that in all cases reinforcement provides a clear improvement in terms of bending capacity and stiffness as compared with the control specimens (without reinforcement). However, improvements in terms of ductility differ considerably depending on the kind of layout.This work has been possible thanks to financial support from the firm DÁVILA Restauración de Monumentos, under research contract No. 3546, titled “Rehabilitación de vigas de madera mediante refuerzos de material compuesto laminado de fibra de carbono (CFRP). Comportamiento mecánico y evaluación de fallos con emisión acústica”

A Formal Verification and Validation of a Low Magnetic Reynolds Number MHD Code for Fusion Applications

© 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksAs the nuclear fusion research advances, resear-chers and engineers focus more on the design of the required systems that complement the nuclear fusion reaction in the plasma of a Tokamak. Some proposals for breeding blankets as well as plasma-facing components’ protection systems are based in liquid metal flows under the Tokamak intense magnetic fields. This creates the situation where induced magnetic field can be neglected and the low magnetic Reynolds number (Re) electric potential formulation can be used to close the magnetohydrodynamic (MHD) system of equations. In the last few years, many different laboratories have developed their own MHD codes to study the liquid metal flow. A formal verification and validation of such codes is necessary to enhance the reliability of the numerical results and to make sure that design decisions are based on safe grounds. The fusion community has made the effort of proposing standardized benchmark cases through which any MHD code should demonstrate its reliability. This work contains the formal validation and verification activities of the MHD code developed some years ago in the Universitat Politecnica de Catalunya (UPC) and currently candidate to contribute to the research done at the Princeton Plasma Phyisics Laboratory (PPPL). The code is implemented over OpenFOAM which makes it easily modifiable. Among these benchmark cases, there are high Hartmann number (Ha), 3-D flows, and magneto-convective interaction cases.Peer ReviewedObjectius de Desenvolupament Sostenible::9 - Indústria, Innovació i InfraestructuraPostprint (published version

Ultrasonic Pulse-Echo Signal Analysis for Damage Evaluation of Metallic Slit-Plate Hysteretic Dampers

This paper proposes a pulse-echo Ultrasonic Testing (UT) methodology to quantify the damage of hysteretic dampers subjected to cyclic loadings. Energy dissipation is known as an innovative strategy for the protection of buildings against earthquakes. It consists of installing special devices called dampers in the construction, which are entrusted to dissipate most of the energy input by the earthquake, thus keeping the main structure basically undamaged. In particular, the hysteretic dampers dissipate the input energy through plastic deformations in their metallic parts. Several moderate ground motions would not exhaust the capacity of the dampers, but they cause damage—plastic deformations in the device. Therefore, continuous or periodic inspections of the damper are required in order to decide upon its eventual replacement. In this particular work, several hysteretic dampers made of stainless steel were subjected to different patterns of low-frequency cyclic loads that caused diverse levels of damage. Each damper underwent pulse-echo UT before and after the cyclic loading. Spectral energy of the echo signals was properly calculated at each damage level in order to define a reliable damage index. The new index has been compared with a well-established mechanical damage index, ID, previously proposed by the authors. A successful correlation was observed, making the pulse-echo UT technique promising for this particular application.This research was supported by the regional government of Andalucía, Consejería de Innovación, Ciencia y Tecnología, Project TEP-02429

Risk factors of hepatic function alterations in hospitalized adult patients treated with short-term parenteral nutrition receiving the same lipid composition at the same dose

Background: High doses and vegetable origin of lipid emulsions (LE) are prominent factors for liver test (LT) alterations in patients treated with parenteral nutrition (PN). This study aims to determine incidence of LT alterations, and risk factors related to these alterations in patients with short term PN with homogenous LE. Methods: Adult non-critically ill hospitalized patients, with normal LTs at the beginning of PN, receiving 0.8 g/kg/day of an olive/soybean LE were included. A paired Student t-test was applied to compare final with initial LT values. LT variation (end vs start of PN) according to type of surgery and infection was studied by means of an analysis of the variance. Univariate and multivariate analyses were constructed to relate the variations of each of the 4 LTs with the adjustment variables. Results: One hundred eighty one patients (66.57 ± 12.89 years; 72.4% men), 66.8% suffered from cancer. Final LT values increased from initial values for gamma-glutamyltransferase (GGT) 2.69 ± 2.49 μkat/L vs 0.55 ± 0.36 μkat/L, alkaline phosphatase (AP) 1.97 ± 1.49 μkat/L vs 1.04 ± 0.33 μkat/L, and alanine aminotransferase (ALT) 0.57 ± 0. 92 μkat/L vs 0.32 ± 0.26 μkat/L. GGT and AP variations were associated with days of PN; GGT, AP and total bilirubin with surgical patients, AP variations with infection, and GGT with cancer. Multivariate analysis: elevation of GGT, AP and ALT was related to infection, days of PN and surgery. Conclusions: Factors that increased the risk of LTs elevation during short term PN treatment were duration of PN, surgery, cancer, and infection associated with oxidative stress

CHOPO. Madera microlaminada estructural de chopo reforzada con tejidos de carbono o basalto

La madera microlaminada (Laminated Veneer Lumber) es un material compuesto de varias capas de chapa extraídas por desenrollo del tronco, todas ellas orientadas en la dirección de la fibra, y encoladas entre sí con un adhesivo a través de un prensado. Por lo general se comercializa en forma de perfiles de sección rectangular para uso estructural. En este trabajo se muestran los resultados mecánicos obtenidos de varios prototipos de LVL de chapas de chopo reforzadas con tejidos de material compuesto de fibra de carbono o basalto para aumentar su rigidez a flexión. El trabajo forma parte de los resultados del proyecto de investigación COMPOP desarrollado en la ETS de Ingeniería Superior de Edificación de la Universidad de Granada (www.compop.ugr.es)

Epstein–Barr Virus and Peri-Implantitis: A Systematic Review and Meta-Analysis

The exponential growth in the use of dental implants in the last decades has been accompanied by an increase in the prevalence of peri-implant disease. It appears that viruses may have pathogenic potential for the development of this pathology. The objective of this systematic review is to study the possible association between the presence of Epstein-Barr virus and the development of peri-implantitis. An electronic search was conducted in PubMed/MEDLINE, Scielo and Embase databases for cross-sectional and case-control studies in humans published up to and including 4 January 2021. Five studies were included in the qualitative analysis. The meta-analysis did not show a statistically significant difference regarding the prevalence of Epstein-Barr virus in the peri-implant sulcus between implants with peri-implantitis and healthy implants. In conclusion, no association between the human herpesvirus 4 and peri-implantitis was found. Further research on this topic is essential to develop more effective treatments