The classical analysis of real-time systems tries to ensure that the instance of every task finishes before its absolute deadline (strict guarantee). The probabilistic approach tends to estimate the probability that it will happen. The deterministic timed behaviour is an important parameter for analysing the robustness of the system. Most of related works are mainly based on the determinism of time constraints. However, in most cases, these parameters are non-precise. The vagueness of parameters suggests the use of fuzzy logic to decide in what order the requests should be executed to reduce the chance of a request being missed. The choice of task parameters and numbers of rules in fuzzy inference engine influences directly generated outputs. Our main contribution is proposing a fuzzy approach to perform real-time scheduling in which the scheduling parameters are treated as fuzzy variables. A comparison of the results of the use of each parameter as linguistic variable is also given.

<p class="MsoNormal" style="text-align: left; margin: 0cm 0cm 0pt; layout-grid-mode: char;" align="left"><span class="text"><span style="font-family: ";Arial";,";sans-serif";; font-size: 9pt;">In this paper, we propose to study and analyze the tasks of a robot and the interaction with its environment, by using the power of Petri nets modelling, especially the timed nets. Our system consists of a robot, a programmable automaton and a computer. We consider the execution of the tasks taking into account the temporal constraints. So, we use the temporal Petri nets to model the whole system and also for its verification. We describe the obtained Petri net and the constraints textually or graphically in the environment TINA, an open source tool dedicated for timed Petri nets. We note that the Petri nets have good qualities of abstraction from the modelling point of view compared to the finite state machines which suffer from the states explosion problem, related to the accessibility graph. Moreover, the consideration of the temporal constraints adds an important complexity to the problem; the system which was carried out successfully in the case "without temporal constraints", can get in a dead lock state in the case "with temporal constraints" if these constraints are not satisfied.</span></span><span style="font-family: ";Arial";,";sans-serif";; font-size: 9pt;"></span></p>

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Les systèmes éducatifs à l'échelle mondiale explorent le potentiel des Ressources Educatives Libres (REL). Cependant, l’adoption des REL reste limitée chez les enseignants. Cette étude exploratoire s’appuie sur le modèle pyramidal d’adoption des REL et a pour objectif de recueillir des renseignements de base sur le niveau de connaissance et d’utilisation des REL. Un questionnaire en ligne a été mis à la disposition de 1297 enseignants marocains. Les résultats révèlent une méconnaissance du concept de REL, des sources où l’on peut les trouver et des cadres d’octroi de licences et de droits d’auteurs chez la majorité des répondants. L’inclusion de l’adoption des REL dans les modules de formation des enseignants est fortement recommandée.