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Identifying relevant machine learning features for multi-sensing platforms is both an applicative limitation to recognize environments and a necessity to interpret the physical relevance of transducers' complementarity in their information processing. Particularly for long acquisitions, feature extraction must be fully automatized without human intervention and resilient to perturbations without significantly increasing the computational cost of a classifier. In this study, we investigate the relative resistance and current modulation of a 24-dimensional conductimetric electronic nose, which uses the exponential moving average as a floating reference in a low-cost information descriptor for environment recognition. In particular, we identified that depending on the structure of a linear classifier, the 'modema' descriptor is optimized for different material sensing elements' contributions to classify information patterns. The low-pass filtering optimization leads to opposite behaviors between unsupervised and supervised learning: the latter favors longer integration of the reference, allowing the recognition of five different classes over 90%, while the first one prefers using the latest events as its reference to cluster patterns by environment nature. Its electronic implementation shall greatly diminish the computational requirements of conductimetric electronic noses for on-board environment recognition without human supervision. [ABSTRACT FROM AUTHOR]

Multivariate data analysis and machine learning classification have become popular tools to extract features without physical models for complex environments recognition. For electronic noses, time sampling over multiple sensing elements must be a fair compromise between a period sufficiently long to output a meaningful information pattern and sufficiently short to minimize training time for practical applications. Particularly when a reactivity's kinetics differ from the thermodynamics in sensitive materials, finding the best compromise to get the most from the data is not obvious. Here, we investigate the influence of data acquisition to improve or alter data clustering for molecular recognition on a conducting polymer electronic nose. We found out that waiting for sensing elements to reach their steady state is not required for classification, and that reducing data acquisition down to the first dynamical information suffices to recognize molecular gases by principal component analysis with the same materials. Especially for online inference, this study shows that a good sensing array is not an array of good sensors, and that new figures of merit should be defined for sensing hardware using machine learning pattern recognition rather than metrology. [ABSTRACT FROM AUTHOR]

We have investigated the electrical characteristics of an AlGaAs/GaAs high electron mobility transistor, in which a layer of InAs self-assembled Quantum Dots (QDs) was inserted below the 2DEG channel. A Negative Differential Capacitance (NDC) appeared in the capacitance–voltage characteristics at a bias of 1 V and at low temperatures (even at room temperature) under different illumination powers using white light bulbs. This results in an increase in negative differential conductance with the increase in frequency and optical power. This also applies to the NDC except that it decreases with increasing frequency. The numerical simulation of the energy band structure of the device confirmed that the conduction band lowers to its minimum at a special bias value of 1 V. The numerical analysis of the evolution of the energy levels in the QD-HEMT follows the appearance of multiple capacitance peaks and their behavior with the gate voltage. [ABSTRACT FROM AUTHOR]

In this work, detailed experimental and theoretical studies are performed on the optoelectronic properties of a Schiff base complex derived from a ninhydrin–glycine (NG) ligand with Al (III) metal. The good functionality and experimental results were confirmed by simulations. The complex shows absorption in the visible range and a blue emission. Furthermore, the charge transport investigation showed that Al–NG has good and balanced hole and electron mobilities equal to 8.44 × 10−6 cm2 V−1 s−1 and 7.10 × 10−6 cm2 V−1 s−1, respectively. The favorable properties make Al–NG complex a promising candidate for the development of organic light-emitting diode (OLED) applications. Using these interesting characteristics, a numerical simulation is performed to have the predictive behavior of indium tin oxide (ITO)/Al–NG/Al OLED device. Finally, we present the effect of thickness and temperature on the OLED electric characteristics. [ABSTRACT FROM AUTHOR]

In this work, we present the different steps in the modeling and implementation of a first-order macroscopic road traffic simulation tool, using Lighthill–Whitham–Richards approach with a Godunov scheme (cell transmission model) and bounded acceleration. The origin–destination traffic movement is based on the definition of partial streams according to their chosen paths or 'routes' from an origin to its destination. The resolution of the traffic conflicts at the nodes level is achieved using a modified dynamic node model. The dynamic node model proposed in this work introduces a new supply function which follows from the extension of the Highway Capacity Manual (2010) model for use in dynamic and instantaneous regime. The method is then applied to reconstruct the traffic at a roundabout in the city of Sousse, Tunisia, known to be over-jammed at rush hour. The results are satisfactory and can be generalized to other intersection types with different priority levels. [ABSTRACT FROM AUTHOR]

The impact of electrodes and active layer thickness on the current–voltage characteristics of Au/Pentacene/Al structure was studied using a physicallybased 2-D simulation by solving Poisson’s, continuity, and drift diffusion equations. The main parameters required for simulation are extracted from the logarithmic representation of experimental current–voltage curves. The simulation results produce an excellent overlapping with the experimental data after including parameters previously found in our model. Finally, the simulation was used to better understand the physical processes together with mechanisms governing the efficiency of the device under investigation and to have a predictive behavior. [ABSTRACT FROM AUTHOR]

In this paper, we use the Extended Huckel Theory coupled with a non-equilibrium green function to calculate the transport proprieties of molecular single electron transistor (MSET). We present the effect of electrode materials on the transport properties in an MSET using a Fullerene (C60) molecule. The operation and performance of this MSET as a gas sensor are studied for the first time using a Fullerene as sensing material. The MSET sensors exhibited a change in the electric characteristic when the sensors were exposed to different gases. The favorable NH3 response characteristics of the MSET sensors were observed from the change in the drain-source current as a function of voltage, when the sensors were exposed to various NH3 concentrations ranging from 40 to 200 ppb. A satisfactory selectivity and remarkable high sensitivity have been found. The present results make our MSET as a very powerful candidate for use in gas sensing/measuring instrument, which allows the detection of toxic gas at low concentration. [ABSTRACT FROM PUBLISHER]

In this paper, a quantum correction computation of the inversion layer of charge density was investigated. This study is carried out for a one-dimensional Metal-lnsulator-Semiconductor (MIS) structure with (100) oriented P-type silicon as substrate. The purpose of this paper is to point out the differences between the semiclassical and quantum-mechanical charge description at the interface AlO/Si, and to identify some electronic properties of our MIS device using different thickness of the high-k oxide and diverse temperature with different carrier statitics (Fermi-Dirak statitics and Boltzmann statitics). In particular, the calculations of capacitance voltage ( C- V), sheet electron density, a relative position of subband energies and their wave functions are performed to examine qualitatively and quantitatively the electron states and charging mechanisms in our device. [ABSTRACT FROM AUTHOR]

Gold screen-printed electrodes coated with thin films of layered double hydroxides containing cobalt and aluminium (Co1.57 Al(OH)xSO4, shortened as CoAl) have been investigated for the design of an electrochemical tyrosinase-based biosensor used for the detection of a complex mixture of polyphenols extracted from green tea. Physicochemical analyses show that the resulted biosensor exhibits very attractive characteristics: a high sensitivity, a large dynamic range (up to 1000 ng.mL ^-1 ), and very low limits of detection (0.33 pg.mL ^-1 and 0.03 pg.mL ^-1 for oxidation and reduction, respectively). [ABSTRACT FROM PUBLISHER]

Sustainable development requiresinter althe reduction of energy consumption and of traffic-induced pollutant emissions. Hybrid electric vehicles (HEVs) are one of the most promising approaches to decrease emissions. This paper considers the influence of hybridization of transport on energy consumption and emissions on single lanes of road traffic. We have developed a micro-simulation tool which integrates instantaneous consumption and emission models. We have modelled microscopic behaviour of vehicles using a full velocity difference model for longitudinal moving. Then, we have used two macroscopic energy consumption models (COPERT and HBEFA) and an instantaneous energy-consumption model concerning the conventional Internal Combustion Engine (ICE) vehicle to illustrate the relevance of microscopic modelling of energy consumption. Furthermore, we have compared the energy consumption of the HEV Toyota Prius with that of the conventional ICE vehicle. An emission model emissions from traffic (EMIT) was also implemented and extended in order to estimate HEV emissions. The model is used to quantify CO2and CO emissions for the HEV Toyota Prius and the conventional ICE vehicle. Moreover, we have studied the influence of fleet hybridization level on energy consumption for congested and uncongested traffic flow state. HEVs can offer major environmental improvements as well as substantial reductions of energy consumption and road traffic emissions. Hybridization is a relevant solution to reduce energy consumption and emissions. [ABSTRACT FROM PUBLISHER]

A two- (2D) and three-dimensional (3D) multiple-tunnel junctions array is investigated. Device structure and electrical characteristics are described. We present a comparison of carriers transport through devices based on polymetallic grains based on master equation and the orthodox theory. The Coulomb blockade effect of 2D and 3D arrays is observed at low and high temperatures. The conduction mechanism is handled by the tunnel effect, and we adopt in addition the thermionic and Fowler-Nordheim emissions. Numerical simulation results focused on flash-memory and photodetector applications. Memory characteristics such as program/erase select gate operation are demonstrated in 2D devices. Also 3D array scheme is discussed for the high-density NCs scalable for photodetector application. [ABSTRACT FROM AUTHOR]

Organic semiconductors have enough molecular versatility to feature chemo-specific electrical sensitivity to large families of chemical substituents via different intermolecular bonding modes. This study demonstrates that one single conducting polymer can be tuned to either discriminate water-, ethanol- or acetone-vapors, on demand, by changing the nature of its dopant. Seven triflate salts differ from mild to strong p-dopant on poly(3-hexylthiophene) sensing micro-arrays. Each material shows a pattern of conductance modulation for the polymer which is reversible, reproducible, and distinctive of other gas exposures. Based on principal component analysis, an array doped with only two different triflates can be trained to reliably discriminate gases, which re-motivates using conducting polymers as a class of materials for integrated electronic noses. More importantly, this method points out the existence of tripartite donor-acceptor charge-transfer complexes responsible for chemospecific molecular sensing. By showing that molecular acceptors can have duality to p-dope semiconductors and to coordinate donor gases, such behavior can be used to understand the role of frontier orbital overlapping in organic semiconductors, the formation of charge-transfer complexes via Lewis acid-base adducts in molecular semiconductors. [Display omitted] • Metal triflates as affordable p-dopants for semiconducting polymers. • Chemically-specific gas sensitivity of metal triflate doped P3HT. • Pattern recognition to identify acetone, water and ethanol with two triflated-P3HT. • Tripartite molecular charge-transfers between gas, dopant and semiconductor. [ABSTRACT FROM AUTHOR]

A two- (2D) and three-dimensional (3D) multiple-tunnel junctions array is investigated. Device structure and electrical characteristics are described. We present a comparison of carriers transport through devices based on polymetallic grains based on master equation and the orthodox theory. The Coulomb blockade effect of 2D and 3D arrays is observed at low and high temperatures. The conduction mechanism is handled by the tunnel effect, and we adopt in addition the thermionic and Fowler-Nordheim emissions. Numerical simulation results focused on flash-memory and photodetector applications. Memory characteristics such as program/erase select gate operation are demonstrated in 2D devices. Also 3D array scheme is discussed for the high-density NCs scalable for photodetector application.