the economic situation in the arab countries is due to several factors as the political crisis in a socio-economic vulnerability. political changes are usually accompanied by a drop in production, a deterioration of macroeconomic balances, a high level of poverty, an appearance of economic corruptions and a structural increase in unemployment. in addition, the expansion of terrorism is a main i...

The discovery of fifth nonlinear region of operation i.e. quasi–chaos is confirmed in this paper after its recently reported two observations in loss and pumpmodulated Erbium doped fiber ring lasers.Quasi-chaos is apparently chaos but its time and physical phase space trajectories actually converge instead of diverging, even for widely separated initial conditions once the system numerical mode...

Control of chaos in the single-mode optically pumped far-infrared NH3 laser is experimentally demonstrated using continuous time-delay control. Both the Lorenz spiral chaos and the detuned period-doubling chaos exhibited by the laser have been controlled. While the laser is in the Lorenz spiral chaos regime the chaos has been controlled both such that the laser output is cw, with corrections of...

The most exciting recent development in nonlinear dynamics is realization that chaos can be useful. One application involves "Secure Communication". Two piecewise linear systems with switching nonlinearities have been taken as chaos generators. In the present work the phenomenon of secure communication with chaos masking has been investigated experimentally. In this investigation chaos which is...