Chaotic Behaviour in Some Discrete –Time Adaptive Control Systems

It has been shown that nonlinear discrete maps can display extremely rich behaviour and under certain parameter conditions to show chaotic phenomenon. This work looks at adaptive control feedback systems which can be represented as nonlinear discrete maps and shows how model mismatch can lead to undesired complicated and chaotic behaviour. Moreover that a discrete-time adaptive control system which can display chaotic behaviour can be extended into higher order systems and the results show that under certain parameter conditions, the higher order systems also behave chaotically. A generalised equation form for the eigenvalues is also given

Noisy Relativistic Quantum Games in Noninertial Frames

The influence of noise and of Unruh effect on quantum Prisoners' dilemma is investigated both for entangled and unentangled initial states. The noise is incorporated through amplitude damping channel. For unentangled initial state, the decoherence compensates for the adverse effect of acceleration of the frame and the effect of acceleration becomes irrelevant provided the game is fully decohered. It is shown that the inertial player always out scores the noninertial player by choosing defection. For maximally entangled initially state, we show that for fully decohered case every strategy profile results in either of the two possible equilibrium outcomes. Two of the four possible strategy profiles become Pareto Optimal and Nash equilibrium and no dilemma is leftover. It is shown that other equilibrium points emerge for different region of values of decoherence parameter that are either Pareto optimal or Pareto inefficient in the quantum strategic spaces. It is shown that the Eisert et al miracle move is a special move that leads always to distinguishable results compare to other moves. We show that the dilemma like situation is resolved in favor of one player or the other.Comment: 14 pages and 6 figure

A Case Study of EFL Teachers’ Perceptions and Practices in Written Corrective Feedback

Based on a mixed-method approach, this interpretive exploratory case study aimed to identify English as Foreign Language (EFL) teachers’ perceptions and practices in Written Corrective Feedback (WCF) in the Saudi context. The study analysed quantitative data gathered from an anonymous custom designed 15-question online survey and qualitative data from an open-ended question (at the end of the online survey) and semi-structured interviews. Participants were one hundred and eighty-four English as a Foreign Language (EFL) teachers (n =184) who responded to the online survey (113 females and 71 males) and 7 participants who responded to the semi-structured interview (5 males and 2 females). The study findings indicated no significant differences between male and female teachers in considering “time” as the main factor in following a particular strategy for written corrective feedback (93%). The results from the semi-structured interviews highlighted the need for further research in written corrective feedback in the Saudi context to address serious issues related to the teachers’ work-load. Some recommendations were identified for further research in written corrective feedback