abstract the present study aimed at discovering the practices and strategies autonomous efl learners pursue in their endeavor to master english. it thus set out in the iranian context, with 60 efl learners, both autonomous and non-autonomous, as participants. the gathered data through a questionnaire and an interview were subjected to content and descriptive analysis. the results showed that bo...

Here we propose six open problems in dynamical systems and chaos theory. The first open problem is concern with rigorous proof of a collection of quadratic ODE systems being non-chaotic. The second problem is for a universal definition of non-chaotic solutions. The third problem is about the number of systems that can have chaotic solutions when the right hand sides are polynomials. The fourth ...

Multi-Agent Systems require coordination mechanisms in order to assemble the behaviour of autonomous and heterogeneous agents and achieve the desired performance of the whole system. Norms are deontic statements employed by these coordination mechanisms which define constraints to the potential excesses of agents’ autonomous behaviour. However, norms are only effective if agents are capable of ...

The existence of a pullback attractor for a reaction-diffusion equations in an unbounded domain containing a non-autonomous forcing term taking values in the space H, and with a continuous nonlinearity which does not ensure uniqueness of solutions, is proved in this paper. The theory of set-valued non-autonomous dynamical systems is applied to the problem. Dedicated to Peter E. Kloeden on his 6...

We consider linear inhomogeneous non-autonomous parabolic problems associated to sesquilinear forms, with discontinuous dependence of time. We show that for these problems, the property of maximal parabolic regularity can be extrapolated to time integrability exponents r 6= 2. This allows us to prove maximal parabolic L r-regularity for discontinuous non-autonomous second-order divergence form ...

We provide sufficient conditions por the existence of periodic solutions of some classes of autonomous and non–autonomous second order differential equations with discontinuous right–hand sides. In the plane the discontinuities considered are given by the straight lines either x = 0, or xy = 0. Two applications of these results are made, one to control systems with variable structure, and the o...