Mediterranean Journal of Modeling and Simulation

11

Authors: Zoubir Abdeslem Benselama, Mohamed A. Bencherif, Abderrezak Guessoum, Mohamed A. Mekhtiche

In this paper, we present the results of our investigation on Autism classifi…cation by applying ensemble classi…ers to disordered speech signals. The aim is to distinguish between Autism sub-classes by comparing an ensemble combining three decision methods, the sequential minimization optimization (SMO) algorithm, the random forests (RF), and the feature-subspace aggregating approach (Feating). The conducted experiments allowed a reduction of 30% of the feature space with an accuracy increase over the baseline of 8.66% in the development set and 6.62% in the test set.

11

Authors: Fayçal Chabni, Rachid Taleb, Abdelkader Mellakhi

The main objective of this paper is to demonstrate the application of Selective Harmonic Elimination PWM (SHEPWM) based on Differential Evolution (DE) optimization algorithm to improve the AC output voltage quality of modified 5-level Cascaded H-Bridge (CHB) inverter. The DE optimization algorithm is used to solve non-linear transcendental equations necessary for the SHEPWM. Computational results obtained from computer simulations presented a good agreement with the theoretical predictions. A laboratory prototype based on STM32F407 microcontroller was built in order to validate the simulation results. The experimental results show the effectiveness of the proposed modulation method.

14

Authors: Nesrine Melzi, Mustapha Temmar, Mohamed Ouali, Abdelkader Melbous

The turning process is one of the best used processes in the mechanical industry. Therefore, the choice of the cutting parameters is very important in order to obtain a good machined surface quality. During the machining operation, the occurrence of vibrations cannot be avoided since these vibrations represent usually the periodic movements of the elastic system around its equilibrium position. The present article proposes to study the chatter vibration during a turning process by using new cutting conditions and using the stability lobes to optimize the surface quality. The main objective is to determine the best solution in the stability area during a turning process where the chatter is nonexistent, because the quality of a final product depends on the stability of the system piece / tool / machine. The proposed work shows its advantages by using a simulation and an experiment work. For the dynamic modeling of our work; analytical, experimental and numerical methods were used.