Boredom is a psychological phenomenon that is defined as a state of hatred or incompatibility with any kind of repetitive experience in situations where liberation from instability is not possible and has several consequences. Boredom is one of the important causes of decreased motivation in EFL learners, and it is necessary to identify the factors affecting it. Therefore, this literature review addresses the state of boredom in relationship with teachers’ immediacy and professional commitment. Reviewing the literature has revealed that while (...) teachers’ immediacy and professional commitments affect EFL learners’ boredom, other factors such as individual differences and environmental factors are in action. However, many studies confirmed that teachers play the most important role in decreasing or increasing learners’ state of boredom. The findings are significant for teacher educators to design more appropriate teacher education programs. (shrink)

This paper proposes an adaptive formation tracking control algorithm optimized by Q-learning scheme for multiple mobile robots. In order to handle the model uncertainties and external disturbances, a desired linear extended state observer is designed to develop an adaptive formation tracking control strategy. Then an adaptive method of sliding mode control parameters optimized by Q-learning scheme is employed, which can avoid the complex parameter tuning process. Furthermore, the stability of the closed-loop control system is rigorously proved by means of matrix (...) properties of graph theory and Lyapunov theory, and the formation tracking errors can be guaranteed to be uniformly ultimately bounded. Finally, simulations are presented to show the proposed algorithm has the advantages of faster convergence rate, higher tracking accuracy, and better steady-state performance. (shrink)

The H ∞ performance of a class of T-S fuzzy systems with Markovian-jump parameters is analyzed. A state feedback controller is designed for T-S fuzzy systems with Markovian-jump parameters. First, a new modal-dependent Lyapunov function composed of closed-loop functions is constructed, which can fully use system status information. Based on this function, the stability conditions with less conservatism are given by linear matrix inequalities. At the same time, a design algorithm for a state feedback controller is proposed for the Markovian-jump-parameters (...) T-S fuzzy systems, which ensures the system’s stability under the condition of H ∞ − γ performance. Simulation results demonstrate that the mentioned method is accurate and practical. (shrink)