Performance evaluation and implementations of MFCC, SVM and MLP algorithms in the FPGA board

One of the most difficult speech recognition tasks is accurate recognition of human-to-human communication. Advances in deep learning over the last few years have produced major speech improvements in recognition on the representative Switch-board conversational corpus. Word error rates that just a few years ago were 14% have dropped to 8.0%, then 6.6% and most recently 5.8%, and are now believed to be within striking range of human performance. This raises two issues - what is human performance, and how far down can we still drive speech recognition error rates? The main objective of this article is the development of a comparative study of the performance of Automatic Speech Recognition (ASR) algorithms using a database made up of a set of signals created by female and male speakers of different ages. We will also develop techniques for the Software and Hardware implementation of these algorithms and test them in an embedded electronic card based on a reconfigurable circuit (Field Programmable Gate Array FPGA). We will present an analysis of the results of classifications for the best Support Vector Machine architectures (SVM) and Artificial Neural Networks of Multi-Layer Perceptron (MLP). Following our analysis, we created NIOSII processors and we tested their operations as well as their characteristics. The characteristics of each processor are specified in this article (cost, size, speed, power consumption and complexity). At the end of this work, we physically implemented the architecture of the Mel Frequency Cepstral Coefficients (MFCC) extraction algorithm as well as the classification algorithm that provided the best results

Estudi del comportament mecànic a compressió d'elastòmers processats per fabricació additiva

Durant els últims anys la impressió 3D ha guanyat rellevància. Aquest motiu ha fet que la fabricació per Filament Fos (FFF), la qual actualment rep el nom de Material Extrusion, en anglès (MEX), s’adapti en diferents àmbits, des del món industrial fins a la investigació biomèdica. L’objectiu d’aquest projecte és la caracterització i l’estudi del material termoplàstic amb propietats elastòmeres, en concret el material Flexfill PEBA 90A, per estudiar la viabilitat de fabricar plantilles de sabates amb aquest material. Sent el PEBA un material nou, flexible, amb aplicacions en l’àmbit de la biomèdica, de la indústria i en general de pràcticament qualsevol àmbit de l’enginyeria. Considerant-se una projecció del futur del materials per la impressió 3D. Es treballarà amb els diferents paràmetres que afecten a les propietats mecàniques, com els paràmetres d’emplenament i l’ús de capes externes durant la impressió, per a posteriorment poder assajar-les a compressió segons la norma ASTM-D695. Paral·lelament s’analitzaran els resultats amb la finalitat de poder caracteritzar una plantilla personalitzada en 3D havent utilitzat un escàner 3D per a poder-ho modelitzar en CAD. A partir dels paràmetres d’impressió variables, es pretén trobar l’òptim resultat.Durante los últimos años la impresión 3D ha ganado relevancia. Este motivo ha hecho que la Fabricación por Filamento Fundido (FFF), la cual actualmente recibe el nombre de Material Extrusion, en inglés (MEX), se adapte en diferentes ámbitos, desde el mundo industrial hasta la investigación biomédica. El objetivo de este proyecto es la caracterización i el estudio del material termoplástico con propiedades elastómeras, en concreto el material Flexfill PEBA 90A, para estudiar la viabilidad de fabricar plantillas de zapatos con este material. Siendo el PEBA un material nuevo, flexible, con aplicaciones en el ámbito de la biomédica, de la industria y en general de prácticamente cualquier ámbito de la ingeniería. Considerándose una proyección de futuro de los materiales por la impresión 3D. Se trabajará con los diferentes parámetros que afectan a las propiedades mecánicas, como los parámetros de relleno y el uso de capas externas durante la impresión, para posteriormente poder ensayarlas a compresión según la norma ASTM-D695. Paralelamente se analizarán los resultados con el fin de caracterizar una plantilla personalizada en 3D habiendo utilizado un escáner 3D para poderlo modelizar en CAD. A partir de los parámetros de impresión variables, se pretende encontrar el óptimo resultado.Over recent years, 3D printing has gained prominence. This is why fused filament fabrication (FFF), now called the Material Extrusion (MEX), is adapted in different areas, from the industrial world to biomedical research. The aim of this project is the characterization and study of the thermoplastic material with elastomer properties, specifically the Flexfilll PEBA 90A material. PEBA is a new flexible material, with applications in the field of biomedical, industry and in general in practically any field of engineering. Considering a projection of the future of materials for 3D printing. Will be working with the different parameters affecting mechanical properties, such as fill parameters and the use of external layers during printing, tested under the ASTM-D695 standard. At the same time, the results will be analysed in order to be able to characterize a customized 3D shoe insole having used a 3D scanner to model it on CAD. Intending to found the best result from variable printing parameters

Study Of The Behaviour Of Wind Turbines Using Doubly Feed Asynchronous Generator During Voltage Dip

The work presented in this communication, describes a solution for wind turbines using Double Fed Induction Generator (DFIG) to overcome the disruption caused by Voltage dips. The solution is to avoid that the strong rotor intensity damage the converter and the generator to disconnect from the network. It will focus on the CROWBAR system to show his contribution and limitations face the grid defaults. Simulations show that the CROWBAR associated with variable resistance gives good results

Ecological desalination of anchovy residues and their mixture with soybean meal for the production of poultry feed: Optimization of waste through response surface methodology (RSM)

Salted anchovy bones are a non-recyclable waste product containing high salt levels. However, they also contain valuable minerals such as calcium, phosphorus, potassium, magnesium, and nitrogen. This study aimed to find a cost-effective method to desalinate anchovy bones while preserving their nutritional value and repurposing them as a raw material for poultry feed. Through various tests, we were able to reduce the salt content of the anchovy bones from 15.4% to 4.7% using a 50/50 percent mixture of tap water and from 15.4% to 3.7% using a mixture of tap water and soybean meal in a 30/70 percent ratio. Combining soybean meal with desalted anchovy bones resulted in a nutritional composition comparable to that found in poultry feed, reducing salt content. The response surface method (RSM) was employed to determine the optimal proportions of desalted anchovy bones (70-90%) and soybean meal (10-30%) and to study the variables affecting the concentrations of NaCl, Ca, P, Ash, and TNM. The study revealed the influence of desalted anchovy bone and soybean meal percentages on these concentrations. This study demonstrates that the method used provides an ideal approach for understanding the interactions between input parameters (% DAR, % SM) and output parameters (NaCl, Ca, P, Ash, and TNM) and shows promising results for the desalination of anchovy bones using a soybean meal cake as well as the feasibility of creating poultry feed

Photoinduced Electron Spin Resonance Phenomenon in α

The photoinduced phenomenon in α-Cr2O3 nanoscaled spherical particles was investigated in the temperature range of 150 up to 315 K. An X-band electron-spin resonance spectrometry was employed to probe the magnetic behavior in α-Cr2O3 under an IR illumination in the nanosecond regime. The photoinduced effect on both low and high field ESR signals appears above 280 K and is remarkably enhanced just below Néel temperature TN. Such a photoinduced ESR phenomenon disappears in a reproducible way in the paramagnetic insulating state which occurs above TN of crystalline α-Cr2O3. In the antiferromagnetic phase, that is, below TN, the shift of the low field absorption could be attributed to the interaction of the light with specific Cr3+ ions located in strongly distorted sites correlated to strong ligand-field effect

Laser fabrication of Cu nanoparticles based nanofluid with enhanced thermal conductivity: Experimental and molecular dynamics studies

Nanofluids are engineered colloidal suspensions of solid nanoparticles in aqueous and non-aqueous base fluids with enhanced thermo-physical characteristics compared to conventional heat transfer fluids (HTFs). In this study, we report on the fabrication of copper nanoparticles-ethylene glycol (CuNPs-EG) nanofluid by using a simple one-step pulsed Nd:YAG laser ablation method to ablate the surface of a pure copper target in EG base fluid under ambient conditions. Structural and morphological analysis confirmed the fabrication of pure spherical shaped CuNPs with average diameter of ~7 nm. Thermal conductivity (k) investigations of CuNPs-EG nanofluid were conducted by using a computational approach where Equilibrium Molecular Dynamics (EMD) simulations integrated with Green-Kubo (EMD-GK) method was used. The obtained EMD-GK results for k were confirmed experimentally through a guarded hot-plate technique within the temperature ranges of 298–318 K. Interestingly, a relative enhancement (η) in the percentage of thermal conductivity of CuNPs-EG nanofluids obtained after an ablation time ta = 5 min was 15% at 318 K, while sample obtained after ta = 30 min showed an enhancement of ~24% in thermal conductivity. These obtained results confirmed the suitability of using a laser based ablation method to fabricate highly efficient nanofluids which could be used as alternatives for conventional HTFs in various heat transfer applications

Therapies in the fight against Covid-19

SARS-Cov-2 Coronavirus is a new emerging virus causing the COVID-19, a respiratory disease outbreak that started in China in December 2019. On January 30, 2020, the World Health Organization has declared this to be a public health emergency of international concern. By September 2020, COVID-19 has affected more than 33 millionin 210 countries and territories worldwide. In this review, we present an overview of the drugs and medicines to combat COVID-19 currently in the clinical trial. We summarize the challenges facing, and opportunities for the discovery of new therapies in this emergency situation

Hydrothermal synthesis of simonkolleite microplatelets on nickel foam-graphene for electrochemical supercapacitors

Nickel foam-graphene (NF-G) was synthesized by chemical vapour deposition followed by facial in situ aqueous chemical growth of simonkolleite (Zn5(OH)8Cl2·H2O) under hydrothermal conditions to form NF-G/simonkolleite composite. X-ray diffraction and Raman spectroscopy show the presence of simonkolleite on the NF-G, while scanning and transmission electron microscopies show simonkolleite micro-plates like structure evenly distributed on the NF-G. Electrochemical measurements of the composite electrode give a specific capacitance of 350 Fg−1 at current density of 0.7 Ag−1 for our device measured in three-electrode configuration. The composite also shows a rate capability of ~87% capacitance retention at a high current density of 5Ag−1,which makes it a promising candidate as an electrode material for supercapacitor applications.The University of Pretoria and the National Research Foundation (NRF) of South Africa.http://www.springer.com/chemistry/physical/journal/10008hb2013ai201

Remarkable thermal conductivity enhancement in Ag—decorated graphene nanocomposites based nanofluid by laser liquid solid interaction in ethylene glycol

We report on the synthesis and enhanced thermal conductivity of stable Ag-decorated 2-D graphene nanocomposite in ethylene glycol based nanofluid by laser liquid solid interaction. A surfactant free nanofluid of Ag nanoparticles anchored onto the 2-D graphene sheets were synthesized using a two-step laser liquid solid interaction approach. In order to understand a pulsed Nd:YAG laser at the fundamental frequency (λ = 1,064 nm) to ablate Ag and graphite composite target submerged in ethylene glycol (EG) to form AgNPs decorated 2-D GNs-EG based nanofluid. From a heat transfer point of view, it was observed that the thermal conductivity of this stable Ag-graphene/EG is significantly enhanced by a factor of about 32.3%; this is highest reported value for a graphene based nanofluid