In this paper, exhaustive analytical investigation based on analyzing the impact of the self-heating phenomenon on the power GaN HEMT performance is proposed. To do so, analytical models for the drain current, power dissipation and lattice temperature variation are developed in order to evaluate the device reliability against the self-heating effects (SHEs). The transistor thermal stability is systematically investigated with respect to the dependence on the buffer layer doping, mole fraction variation, and layer thickness. In this work, the electrical and thermal performance of power GaN HEMT structure is investigated. Also, device design parameters dependent characteristics on thermal stability and immunity are observed and analyzed. The obtained results provide new insight for bridging the gap between high power performances with thermal stability factor.

A concrete incorporation of mobile robots in more industrial applications depends mainly on their ability to navigate safely in industrial environments while fulfilling the assigned tasks. One of the important tasks in wheeled mobile robotics is trajectory tracking, which adds temporal constraints on the robot navigation. The employment of trajectory tracking strategies with obstacle avoidance capabilities is essential to avoid time waste and inefficiency in mobile robots industrial integration. In this paper, we present a navigation algorithm intended for differential drive mobile robots, that combines trajectory tracking with obstacle avoidance. Obstacle detection is accomplished using sonar range sensors and the navigation is found on kinematic control and vector field histogram approach. Demonstration with simulations in V-rep environment is presented where Pioneer3DX successfully avoided obstacles while tracking a trajectory.

In this paper, we propose a new method for Bulk waves detection of an acoustic microwave signal during the propagation of acoustic microwaves in a piezoelectric substrate (Lithium Niobate LiNbO₃). We have used the classification by probabilistic neural network (PNN) as a means of numerical analysis in which we classify all the values of the real part and the imaginary part of the coefficient attenuation with the acoustic velocity in order to build a model from which we note the Bulk waves easily. These singularities inform us of presence of Bulk waves in piezoelectric materials.

La conception, le développement et l'évaluation des performances thermiques d'un cuiseur solaire boîte trapèze à surface réceptrice inclinée (CSBSRI) est présenté dans le présent article. Une chaîne d'acquisition de données équipée de divers instruments de mesure est installée pour le contrôle du système. Les profils thermiques des différentes composantes du cuiseur ont été mesurés au site saharien de Ghardaïa pour différentes conditions climatiques durant la saison hivernale et estivale. L'analyse des performances du cuiseur solaire est évaluée au moyen de la puissance de cuisson ajustée, qui ; se situant dans l'intervalle des Normes du Standard de Funk, met le cuiseur réalisé dans la gamme des Standards Internationaux. Les tests expérimentaux entrepris démontrent que le cuiseur proposé, avec une surface d'ouverture inclinée ; améliore considérablement les performances thermiques du cuiseur solaire, il est de ce fait adapté à la cuisson des aliments en été et en hiver où la hauteur du soleil est faible.

The complexity of systems in the current process industry is conducive to the concerns of industrialists about the risks that may be inherent in these systems. Risk reduction measures should be considered and implemented to reduce the initial risk to an acceptable level. This is usually achieved by using a combination of systems that provide security, inter alia, Safety Instrumented Systems (SIS). The implementation of a SIS requires the determination of its Safety Integrity Level (SIL) which it must have in order to attain the tolerable risk. The standards IEC 61508 and 61511 provide a framework for the determination of SIL and propose different methods. The objective of this work consists in proposing an approach of allocation and optimization of the security barriers, using the methods of risk graph and LOPA (Layer Of Protection Analysis) In order to evaluate the performance of the safety measures put in place for the control of risks in a hydrocarbon storage station. A cost benefit analysis (CBA), as a decision support tool, is carried out to improve the safety level of the process studied.