In this paper, we present a new ultra fast detector called Low Gain Avalanche Detector (LGAD) with low internal gain. The LGAD is fabricated with conventional APD technology with a modified doping profile, in the multiplication region, which affects the device performance such as: breakdown, multiplication gain and noise factor. For this reason, a numerical method based on Newton-Raphson calculation is proposed to estimate the electrostatic potential and electric field models of low gain avalanche detectors (LGADs) in order to investigate their performances. These models have been validated by their agreement with TCAD numerical simulation results. The effect of Boron doping profile, with different doses in the multiplication region, on the LGAD electrical performance is studied for various device structures in order to extend the device capability to its limit. In addition, LGAD devices are simulated for different temperature considering the effect of the temperature on the multiplication gain.

Let E,F,G,D be infinite complex Banach spaces and B(F,E) the Banach space of all bounded linear operators from F into E. Consider A1,A2∈B(F,E), B1,B2∈B(D,G)B1,B2∈B(D,G). Let MA1,B1:X→A1XB1 be the multiplication operator on B(G,F) induced by A1,B1. In particular, LA1=MA1,I and RB1=MI,B1, where I is the identity operator are the left and the right multiplication operators, respectively. The elementary operator Ψ defined on B(G,F)B(G,F) is the sum of two multiplication operators Ψ=MA1,B1+MA2,B2. This paper gives necessary and sufficient conditions for the existence of a common solution of the operator equations MA1,B1(X)=C1 and MA2,B2(X)=C2 and derive a new representation of the general common solution via the inner inverse of the elementary operator Ψ; we apply this result to determine new necessary and sufficient conditions for the existence of a Hermitian solution and a representation of the general Hermitian solution to the operator equation MA,B(X)=C. As a consequence, we obtain well-known results of Dajic´ and Koliha.

The magnetohydrodynamics (MHD) is an important interdisciplinary field. It is the interaction between an electromagnetic field and an electrically conducting fluid. Electromagnetic pumps are widely used for the transportation of the fluids in a variety of technological processes. The advantage of these devices is that permits the pumping of liquids without moving parts. The design of the pump is considered as an optimization problem where the objective function is the minimum of the MHD pump mass with both geometrical and electromagnetic contraints type. The obtained optimization results using the finite volume method with Matlab software show the performances of the used stochastic simulated annealing method.

In this paper, we study the intermediate band solar cell (IBSC) and present the influence of the physical and geometrical parameters of the solar cell with intermediate band using the model of our approach based on genetic algorithms (GAs). These parameters include absorber width, the acceptor and donor concentration and the absorption coefficient. This analysis based on genetic algorithm is used to improve these parameters and systematically enhance the solar cell performances.

This paper presents the optimization, elaboration and characterization of a new TCO (Transparent Conductive Oxides) electrode based on ITO/Ag/ITO multilayer design that enables overcoming the trade-off between the electrical and optical properties. A new hybrid approach combining the investigated design and Particle Swarm Optimization (PSO) technique is conducted with the aim of maximizing the Haacke Figures of merit (FoM). It is found that the optimized ITO/Ag/ITO tri-layered design paves a new path toward achieving a high FoM of 125 × 10-3Ω-1. Such improvement is attributed to the improved light management achieved by the efficient modulation of the Ag sub-layer geometry. Subsequently, the optimized multilayer design is fabricated using RF magnetron sputtering technique. The structural, optical and electrical properties associated with the deposited ITO/Ag/ITO multilayer structure are also analyzed. It is found that the fabricated TCO-based electrode shows a high transmittance over than 94.1% and a low sheet resistance of 4.5Ω × sq-1, which is in good agreement with the theoretical predictions. Therefore, the proposed design methodology based on experiments assisted by PSO metaheuristic approach offers exciting opportunities for bridging the gap between transparency and conductivity characteristics. This makes the elaborated ITO/Ag/ITO multilayer design suitable for high-performance optoelectronic applications.

With the huge increase of large-scale multimedia over Internet, especially images, building Content-Based Image Retrieval (CBIR) systems for large-scale images has become a big challenge. One of the drawbacks associated with CBIR is the very long execution time. In this article, we propose a fast Content-Based Image Retrieval system using Spark (CBIR-S) targeting large-scale images. Our system is composed of two steps. (i) image indexation step, in which we use MapReduce distributed model on Spark in order to speed up the indexation process. We also use a memory-centric distributed storage system, called Tachyon, to enhance the write operation (ii) image retrieving step which we speed up by using a parallel k-Nearest Neighbors (k-NN) search method based on MapReduce model implemented under Apache Spark, in addition to exploiting the cache method of spark framework. We have showed, through a wide set of experiments, the effectiveness of our approach in terms of processing time.

Risk mapping is the foundation of the risk prevention strategy. It allows for the understanding of all factors that may affect the activities. It is a collective decision based on negotiation between the actors. Argument-based negotiation accelerates the negotiation process and converges it toward a final and common decision. It is in this context that this paper aims to illustrate the contribution of the improved PCA and AHP tools, considered as arguments, to the classification of major accident risks.