A Decision Tree and S-Transform Based Approach for Power Quality Disturbances Classification

In this paper, it is presented an automated classification based on S-transform as feature extraction tool and Decision Tree as algorithm classifier. The signals generated according to mathematical models, including complex disturbances, have been used to design and test this approach, where noise is added to the signals from 40dB to 20dB. Finally, several disturbances, simple and complex, have been considered to test the implemented system. Evaluation results verifying the accuracy of the proposed method are presented.IEE

Implementation of two color method to investigate late cycle soot oxidation process in a CI engine under low load conditions

[EN] Soot emissions from diesel engines are an important concern in meeting emissions regulations. Soot emissions are the result of two competing processes: soot formation and soot oxidation. Mechanisms of soot formation are discussed extensively in the literature. Equivalence ratio at lift-off length along with residence time and gas temperature play an important role for soot formation in a diffusion flame. Mixing capability and bulk gas temperature are the most important parameters that influence the in-cylinder soot oxidation process. Normally, research studies of soot formation-oxidation processes have been developed under controlled and not completely representative conditions of engine operation in the field. Therefore, the main objective of this work was to develop a simplified methodology to evaluate in cylinder soot oxidation under 'real' engine conditions. In particular the impact of mixing process and bulk gas temperature on late cycle soot oxidation was evaluated. The experimental measurements were made in a production light-duty diesel engine varying those parameters that have been demonstrated in the literature as the most relevant in soot formation - oxidation processes; injection pressure, ambient density and intake air temperature. To measure soot, two color method was applied by means of an optoelectronic pyrometer. To evaluate the mixing capability a specific "tracer" Apparent Combustion Time (ACT(-1)) based on the experimental heat release and injection parameters was defined. The relationship between both parameters was used to explain the soot oxidation process. (C) 2016 Elsevier Ltd. All rights reserved.The authors acknowledge General Motors Global Research & Development for supporting this research.López, JJ.; Martín, J.; García Martínez, A.; Villalta-Lara, D.; Warey, A. (2017). Implementation of two color method to investigate late cycle soot oxidation process in a CI engine under low load conditions. Applied Thermal Engineering. 113:878-890. doi:10.1016/j.applthermaleng.2016.11.095S87889011

CMOS First-Order All-Pass Filter With 2-Hz Pole Frequency

A CMOS fully integrated all-pass filter with an extremely low pole frequency of 2 Hz is introduced in this paper. It has 0.08-dB passband ripple and 0.029-mm 2 Si area. It has 0.38-mW power consumption in strong inversion with ±0.6-V power supplies. In subthreshold, it has 0.64-μW quiescent power and operates with ±200-mV dc supplies. Miller multiplication is used to obtain a large equivalent capacitor without excessive Si area. By varying the gain of the Miller amplifier, the pole frequency can be varied from 2 to 48 Hz. Experimental and simulation results of a test chip prototype in 130-nm CMOS technology validate the proposed circuit

Job Stability and Gender Perspectives: Application of a Logistic Regression Model

Several changes have been taking place in the labour market since the 1970s that have created the right climate to spur organisations and workers to demand greater flexibility in employment. In this context, temporary employment has been the focus of many research papers and temporary contracts have been used as a tool to achieve labour flexibility. In order to understand the situation in Andalusia (Spain), this paper aims to identify the decisive factors in permanent employment. To this end, starting hypotheses will be defined about the decisive factors in permanent employment and the positive or negative significance of their influence; the starting hypotheses will then be tested empirically using a logistic regression model on a sample population of wage earners in Andalusia. In the second stage, given that the ratio of temporary contracts is much higher among women, the variable ‘gender’ is likely to be decisive in the construction of the regression model, therefore the decisive factors for permanent employment in Andalusia will be evaluated separately for men and women, in order to calibrate the impact of gender on job stability. Finally, based on the estimated probabilities of having a permanent job depending on gender, the degree of labour discrimination faced by women in the Andalusian labour market will be analysed

Effects of empowering leadership under boundary conditions in the hospitality industry

This study tests the positive effects of empowering leadership (ELSH) under boundary conditions in the hospitality industry. We propose the existence of an interactive process through which ELSH behaviors interact with employees’ personality type to condition their engagement, which in turn influences their extra-role service behavior. We use data from 294 employees and structural equation modeling. The results show that the interaction of ELSH with employees’ independent and interdependent personality is negatively related to their engagement. This decrease in engagement is then reflected in decreased extra-role service behaviors due to the positive relationship between engagement and extra-role service. These findings suggest that self-construal is a significant boundary condition capable of changing the positive relationship between ELSH and engagement to a negative one. Not considering this relationship when establishing a leadership strategy such as ELSH in the hospitality context could render efforts to achieve the goal of high-quality service ineffective.European Regional Development Fund (European Union)Spanish Government ECO2017-84138-PJunta de Andalucia A-SEJ-154-UGR18University of Granada/CBU

An Op-Amp Approach for Bandpass VGAs With Constant Bandwidth

Two approaches to implement variable gain amplifiers based on Miller op-amps are discussed. One has true constant bandwidth while the other has essentially reduced bandwidth variations with varying gain. Servo-loops and ac coupling techniques with quasi floating gate transistors are used to provide a bandpass response with very low cutoff frequency in the range of hertz. In practice, one of the schemes is shown to have bandwidth variations close to a factor two while the second one has true constant bandwidth over the gain tuning range. Experimental results of test chip prototypes in 180-nm CMOS technology verify the theoretical claims

±0.25-V Class-AB CMOS Capacitance Multiplier and Precision Rectifiers

Reduction of minimum supply requirements is a crucial aspect to decrease the power consumption in VLSI systems. A high-performance capacitance multiplier able to operate with supplies as low as ±0.25 V is presented. It is based on adaptively biased class-AB current mirrors which provide high current efficiency. Measurement results of a factor 11 capacitance multiplier fabricated in 180-nm CMOS technology verify theoretical claims. Moreover, low-voltage precision rectifiers based on the same class-AB current mirrors are designed and fabricated in the same CMOS process. They generate output currents over 100 times larger than the quiescent current. Both proposed circuits have 300-nW static power dissipation when operating with ±0.25-V supplies

Profiled support vector machines for antisense oligonucleotide efficacy prediction

BACKGROUND: This paper presents the use of Support Vector Machines (SVMs) for prediction and analysis of antisense oligonucleotide (AO) efficacy. The collected database comprises 315 AO molecules including 68 features each, inducing a problem well-suited to SVMs. The task of feature selection is crucial given the presence of noisy or redundant features, and the well-known problem of the curse of dimensionality. We propose a two-stage strategy to develop an optimal model: (1) feature selection using correlation analysis, mutual information, and SVM-based recursive feature elimination (SVM-RFE), and (2) AO prediction using standard and profiled SVM formulations. A profiled SVM gives different weights to different parts of the training data to focus the training on the most important regions. RESULTS: In the first stage, the SVM-RFE technique was most efficient and robust in the presence of low number of samples and high input space dimension. This method yielded an optimal subset of 14 representative features, which were all related to energy and sequence motifs. The second stage evaluated the performance of the predictors (overall correlation coefficient between observed and predicted efficacy, r; mean error, ME; and root-mean-square-error, RMSE) using 8-fold and minus-one-RNA cross-validation methods. The profiled SVM produced the best results (r = 0.44, ME = 0.022, and RMSE= 0.278) and predicted high (>75% inhibition of gene expression) and low efficacy (<25%) AOs with a success rate of 83.3% and 82.9%, respectively, which is better than by previous approaches. A web server for AO prediction is available online at . CONCLUSIONS: The SVM approach is well suited to the AO prediction problem, and yields a prediction accuracy superior to previous methods. The profiled SVM was found to perform better than the standard SVM, suggesting that it could lead to improvements in other prediction problems as well

The HL-60 human promyelocytic cell line constitutes an effective in vitro model for evaluating toxicity, oxidative stress and necrosis/apoptosis after exposure to black carbon particles and 2.45 GHz radio frequency

The cellular and molecular mechanisms by which atmospheric pollution from particulate matter and/or electromagnetic fields (EMFs) may prove harmful to human health have not been extensively researched. We analyzed whether the combined action of EMFs and black carbon (BC) particles induced cell damage and a pro-apoptotic response in the HL-60 promyelocytic cell line when exposed to 2.45 GHz radio frequency (RF) radiation in a gigahertz transverse electromagnetic (GTEM) chamber at sub-thermal specific absorption rate (SAR) levels. RF and BC induced moderately significant levels of cell damage in the first 8 or 24 h for all exposure times/doses and much greater damage after 48 h irradiation and the higher dose of BC. We observed a clear antiproliferative effect that increased with RF exposure time and BC dose. Oxidative stress or ROS production increased with time (24 or 48 h of radiation), BC dose and the combination of both. Significant differences between the proportion of damaged and healthy cells were observed in all groups. Both radiation and BC participated separately and jointly in triggering necrosis and apoptosis in a programmed way. Oxidative-antioxidant action activated mitochondrial anti-apoptotic BCL2a gene expression after 24 h irradiation and exposure to BC. After irradiation of the cells for 48 h, expression of FASR cell death receptors was activated, precipitating the onset of pro-apoptotic phenomena and expression and intracellular activity of caspase-3 in the mitochondrial pathways, all of which can lead to cell death. Our results indicate that the interaction between BC and RF modifies the immune response in the human promyelocytic cell line and that these cells had two fates mediated by different pathways: necrosis and mitochondria-caspase dependent apoptosis. The findings may be important in regard to antimicrobial, inflammatory and autoimmune responses in humansS

Tunable magneto-photonic response of nickel nanostructures

In this letter, we present both experimental and numerical studies of the magneto-optical (MO) properties of nickel infiltrated opals. Ni can show interesting MO properties that can be controlled by nanostructuration through colloidal crystals templating. Nanostructuration allows the coupling of light to surface plasmon modes of Ni, and a clear dependence of the MO response as a function of the structural parameters of the template has been observed. This dependence can be used in future tunable devices such as switchers or MO modulators. © 2011 American Institute of Physics.This work has been partially supported by EU FP7 (NoE Nanophotonics 4 Energy Grant No. 248855 and NMP3-SL-2008-214107-Nanomagma); the CSIC PIF08-016, the Spanish MICINN (CSD2007-0046-Nanolight.es, CSD2008-00023-Funcoat, MAT2009-07841-GLUSFA, MAT2008-06765-C02-01/NAN-MAGPLAS) and Comunidad de Madrid (S2009/MAT-1756-PHAMA and S2009/TIC–1476- MICROSERES).Peer Reviewe