RBF-Neural network applied to the quality classification of tempered 100Cr6 steel cams by the multi-frequency nondestructive eddy current testing

Producción CientíficaThis article proposes a Radial Basis Function Artificial Neural Network (RBF-ANN) to classify tempered steel cams as correctly or incorrectly treated pieces by using multi-frequency nondestructive eddy current testing. Impedances at five frequencies between 10 kHz and 300 kHz were employed to perform the binary sorting. The ANalysis Of VAriance (ANOVA) test was employed to check the significance of the differences between the impedance samples for the two classification groups. Afterwards, eleven classifiers were implemented and compared with one RBF-ANN classifier: ten linear discriminant analysis classifiers and one Euclidean distance classifier. When employing the proposed RBF-ANN, the best performance was achieved with a precision of 95% and an area under the Receiver Operating Characteristic (ROC) curve of 0.98. The obtained results suggest RBF-ANN classifiers processing multi-frequency impedance data could be employed to classify tempered steel DIN 100Cr6 cams with a better performance than other classical classifiers

Control of natural fractures in historical quarries via 3D point cloud analysis

This paper applies remote sensing techniques and 3D point cloud (3DPC) analysis to the study of historical quarries and the relationship between old quarry landscapes and the natural fracture systems of rock massifs. Ancient quarry landscapes present particular characteristics and different features from those of modern quarries. Consequently, specific considerations are needed when historical extractive places are studied. The proposed method is based on terrestrial 3D laser scanners and the structure from motion technique with remotely piloted aircraft systems. Additional specific fieldwork is required to identify and characterise quarry faces from old, blurry outcrops. A case study of the 18th century “Rambla Honda” quarries in La Romana (Alicante, SE Spain) is presented. The comparison between the fieldwork and 3DPC analysis enables the numbers and orientations of both (1) the discontinuity sets within the rock mass facilitating extraction and (2) the planes resulting from block extraction (traditional quarry faces) to be determined. The comparative analysis reveals how the stonecutters managed the extraction. The results show that structural and stratigraphic discontinuities act as planes of weakness for block extraction and determine the optimum orientation of the quarry face for minimising efforts and rock waste. The final quarry landscape is formed from the superposition of natural and artificial surfaces, but currently they appear eroded and partially covered by silting and plants. The proposed methodology contributes to distinguishing both natural and artificial discontinuities and to achieving a comprehensive knowledge of these cultural places.This research was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2017-85244-C2-1-P, the University of Alicante (Vigrob-157 and GRE18-15), and the Spanish Ministry of Science and Innovation (Grants PID2020-116896RB-C21 and PID2020-116896RB-C22 funded by MCIN/AEI/10.13039/501100011033)

OSS integration issues and community support: an integrator perspective

The reuse and integration of Open Source Software (OSS) components provided by OSS communities is becoming an economical and strategic need for today’s organizations. The integration of OSS components provides many benefits, but also risks and challenges. One of the most important risks is the lack of effective and timely OSS community support for dealing with possible integration problems. For gaining an understanding of the common problems that organizations face when integrating OSS components, and the role played by OSS communities, we performed an exploratory study on 25 OSS integration projects from different European organizations. The results show that the main way of reducing integration problems was the use of OSS components from well-established communities; therefore very few integration problems were identified. In most of the cases these problems were successfully solved with the support from the OSS community and/or colleagues. In addition, contrary to the common belief that understanding code from someone else is a hard and undesirable task, some integrators consider OSS code even more understandable than their own code.Peer ReviewedPostprint (author's final draft

Generalized MGF of Beckmann Fading with Applications to Wireless Communications Performance Analysis

The Beckmann distribution is a general multipath fading model for the received radio signal in the presence of a large number of scatterers, which can thence be modeled as a complex Gaussian random variable where both the in-phase and quadrature components have arbitrary mean and variance. However, the complicated nature of this distribution has prevented its widespread use and relatively few analytical results have been reported for this otherwise useful fading model. In this paper, we derive a closed-form expression for the generalized moment-generating function (MGF) of the signal-to-noise ratio (SNR) of Beckmann fading, which permits to circumvent the inherent analytical complexity of this model. This is a new and useful result, as it is key for evaluating several important performance metrics of different wireless communication systems and also permits to readily compute the moments of the output SNR. Thus, we obtain simple exact expressions for the energy detection performance in Beckmann fading channels, both in terms of the receiver operating characteristic (ROC) curve and of the area under ROC curve. We also analyze the outage probability in interference limited systems affected by Beckmann fading, as well as the outage probability of secrecy capacity in wiretap Beckmann fading channels. Monte Carlo simulations have been performed to validate the derived expressions.Universidad de Málaga. Campus de Excelencia Internacional. Andalucía Tech

Control de instrumentos mediante el bus GPIB programado con MATLAB

El proyecto que se expone a continuación está dedicado al control de instrumentos mediante el bus de instrumentación GPIB programado con el software Matlab. Está dividido en dos partes. La primera, será llevada a cabo en el laboratorio de docencia y el objetivo será controlar el osciloscopio y el generador de funciones. Como ejemplo del control realizado se desarrollará una aplicación que permitirá obtener el diagrama de Bode de módulo de cualquier sistema electrónico. La segunda parte será llevada a cabo en el laboratorio de investigación y el objetivo será controlar el analizador de semiconductores. En este caso, la aplicación desarrollada permitirá la realización de medidas para la caracterización de transistores. Las aplicaciones de ambas partes estarán realizadas mediante una interfaz gráfica de usuario diseñada con la herramienta GUIDE de Matlab.El projecte que s'exposa a continuació està dedicat al control d'instruments mitjançant el bus d'instrumentació GPIB programat amb el software Matlab. Està dividit en tres parts. La primera, es durà a terme en el laboratori de docència i l'objectiu serà controlar l'oscil·loscopi i el generador de funcions. Com exemple del control realitzat es realitzarà una aplicació que permetrà obtenir el diagrama de Bode de mòdul de qualsevol sistema electrònic. La segona part es durà a terme en el laboratori d'investigació i l'objectiu serà controlar l'analitzador de semiconductors. En aquest cas, l'aplicació realitzada permetrà la realització de mesures per a la caracterització de transistors. Les aplicacions de les dues parts seran realitzades mitjançant una interfaç gràfica d'usuari dissenyada amb l'eina GUIDE de Matlab.The project that follows is dedicated to the control of instruments with the GPIB instrumentation bus programmed with Matlab software. It's divided into two parts. The first will be made in the teaching laboratory and the objective is to control the oscilloscope and function generator. As an example of the monitoring executed, we will develop an application to obtain the Bode plot of any electronic system module. The second part will be made in the research laboratory and the objective is to control the semiconductor analyzer. In this case, the developed application will allow taking measurements for the characterization of transistors. The applications of both parts will be made by a graphical user interface designed with the Matlab's GUIDE tool

Efectos del ejercicio físico extracurricular vigoroso sobre la atención de escolares

El objetivo de este trabajo fue analizar el efecto sobre la atención de escolares de dos programas de actividad física (moderada y alta intensidad). Participaron 94 niños (n = 52) y niñas (n =42), (Edad M = 8,20; DT = 0,70) de la ciudad de Granada (España). Se empleó un diseño cuasi experimental con un grupo control y otro experimental. Se analizó amplitud de la atención y atención selectiva. Como variable de control se evaluó la aptitud cardiorrespiratoria a través de consumo de oxígeno máximo y la velocidad pico alcanzada durante actividad aeróbica máxima. Se aprecian efectos significativos a favor del programa de alta intensidad sobre dos pruebas de span atencional y ejercicios de atención selectiva, así como en valores de condición física. Se concluye que la práctica física de alta intensidad intermitente, practicada de manera regular, podría tener implicaciones positivas sobre el rendimiento cognitivo de niños y que la mejora de la condición física podría ser uno de los factores vinculados a estos cambios.The aim of this study was to analyze the effect of two programs of physical activity (moderate and high intensity physical activity), in the levels of attention of a sample of young in scholar aged. 94 children, boys=52 and girls=42 (Age M = 8.20; SD = 0.70) from Granada (Spain) participated in the investigation. A quasi-experimental design was used, with control and experimental group. Evidence of attentional span and search items on matrices with the purpose of analyzing the amplitude of the attention and selective attention were applied. As a control variable, cardiorespiratory fitness by maximum oxygen uptake and peak speed reached during maximal aerobic activity was evaluated. The results showed significant effects in favor of high-intensity program on two tests of attentional span and exercises selective attention, as well as the values of fitness. These data suggest that the physical practice of intermittent high intensity practiced regularly could have positive implications on cognitive performance of children and improving the physical condition could be one of the factors linked to these changes.O objetivo deste estudo foi analisar o efeito de dois programas de atividade física (de intensidade moderada e alta) em atenção o nível cognitivo para a escola. 94 estudantes participaram, 52 do sexo masculino, 42 do sexo feminino (Idade M = 8,20, DP = 0,70) da cidade de Granada (Espanha). Um design quase-experimental foi utilizado com um grupo controle e um grupo experimental. Amplitude de atenção e atenção seletiva foram analisados. Como variável de controle foi avaliada a aptidão cardiorrespiratória através do consumo máximo de oxigênio e velocidade de pico alcançado durante a atividade aeróbica máxima. Efeitos significativos são vistos em favor do programa de alto intensidade e dois exercícios de amplitude e exercícios de atenção selectiva, bem como valores de aptidao física. Conclui-se que a prática física de alta intensidade intermitente, praticado regularmente, pode ter implicações positivas sobre o desempenho cognitivo das crianças e condição física melhoria poderia ser um dos fatores ligados a essas mudanças

MOSFET degradation dependence on input signal power in a RF power amplifier

Aging produced by RF stress is experimentally analyzed on a RF CMOS power amplifier (PA), as a function of the stress power level. The selected circuit topology allows observing individual NMOS and PMOS transistors degradations, as well as the aging effect on the circuit functionality. A direct relation between DC MOSFETs and RF PA (gain) parameters has been observed. NMOS degradation (both in mobility and Vth) is stronger than that of the PMOS. Results suggest that transistors mobility reduction is the main cause of the RF degradation in this circuit.Postprint (published version

Performance and emissions of a series hybrid vehicle powered by a gasoline partially premixed combustion engine

[EN] This work evaluates the performance and emissions of the series hybrid vehicle concept powered by a gasoline partially premixed internal combustion engine. To do so, experimental data was collected from a Volvo VED-D4 Euro 6 four-cylinder compression ignition engine running under gasoline partially premixed combustion. Two series hybrid vehicle models were developed in GT-Power (R), which were fed with the experimental data to evaluate the potential of the hybrid concept. First of all, the battery charging strategy of the hybrid vehicles was optimized in terms of number of power levels and operating conditions. For this, a design of experiments was performed in GT-Power (R), which enabled to obtain a predictive model of the performance and emissions. The predictive model was used to obtain the optimized NOx-fuel consumption Pareto frontiers for each charging strategy proposed. Finally, the GT-Power (R) vehicle models were run with the optimal operating conditions (selected from each Pareto) in both the new European driving cycle and worldwide harmonized light vehicles test cycle. The results show that the hybrid powertrain running with partially premixed combustion is able to achieve similar or better performance than the commercial diesel vehicle with low engine-out emissions. Moreover, comparing the results from both vehicles, it was confirmed that the hybridization results in better improvements when applied to urban traffic than for highway conditions where the power request is higher and the potential for regenerative braking is reduced.The authors gratefully acknowledge FEDER and Spanish Ministerio de Economia y Competitividad for partially supporting this research through TRANCO project (TRA2017-87694-R). The authors also gratefully acknowledge the KCFP Engine Research Center (Swedish Energy Agency grant number 22485-4) for partial support of this research.García Martínez, A.; Monsalve-Serrano, J.; Lago-Sari, R.; Dimitrakopoulos, N.; Turnér, M.; Tunestål, P. (2019). Performance and emissions of a series hybrid vehicle powered by a gasoline partially premixed combustion engine. Applied Thermal Engineering. 150:564-575. https://doi.org/10.1016/j.applthermaleng.2019.01.035S56457515

A Growth Modulation Index-Based GEISTRA Score as a New Prognostic Tool for Trabectedin Efficacy in Patients with Advanced Soft Tissue Sarcomas: A Spanish Group for Sarcoma Research (GEIS) Retrospective Study

L-sarcoma; Índex de modulació del creixement; SarcomaL-sarcoma; Indice de modulación del crecimiento; SarcomaL-sarcoma; Growth modulation index; SarcomaThe aim of this study was to identify an easily reliable prognostic score that selects the subset of advanced soft tissue sarcoma (ASTS) patients with a higher benefit with trabectedin in terms of time to progression and overall survival. A retrospective series of 357 patients with ASTS treated with trabectedin as second- or further-line in 19 centers across Spain was analyzed. First, it was confirmed that patients with high growth modulation index (GMI > 1.33) were associated with the better clinical outcome. Univariate and multivariate analyses were performed to identify factors associated with a GMI > 1.33. Thus, GEISTRA score was based on metastasis free-interval (MFI ≤ 9.7 months), Karnofsky 1.33. The lowest GEISTRA score showed a median of time-to-progression (TTP) and overall survival (OS) of 5.7 and 19.5 months, respectively, whereas it was 1.8 and 3.1 months for TTP and OS, respectively, for the GEISTRA 4 score. This prognostic tool can contribute to better selecting candidates for trabectedin treatment in ASTS.This research was funded by the Spanish Group for Research on Sarcoma (grant number: NA) and partially by PharmaMar. PharmaMar S.A. did not have any role in study design, or in collection, analysis and interpretation of data