PID control of unstable plants;

The results indicate that the H_∞output feedback design of such a non-minimum-phase unstable plant is far less robust.

Based on the H ∞ frequency domain optimal control theory PID controllers were designed for open loop unstable processes with time delay.

The simulation results show that the proposed analytical controller design scheme achieves shorter rise-time and smaller over-shoot, better dynamic performance and robustness is also provided for the first order unstable processes with large dead time.

It shows that the severe aircraft icing has close relations to the convective instability meteorological conditions between 3000 and 7000 high above the sea level in the east of the Tibetan Plateau.

In this paper, a modified symmetry instability criterion for thermal wind non equilibrium basic flow is deduced by using two dimensional liner equations with Boussinesq approximation of moist air.

Advances in synoptic analysis and application of symmetric instability theory

The results show that the existence of the maximum of inertial stability in the left front of the low level jet is favorable to the accumulation of moist thermal energy and that the conditional symmetric instability or convective instability can be expected in this region.

The dynamic stability of meso-scale symmetric perturbation is discussed in terms of two-dimensional fluid-dynamics equations under anelastic approximation,which obtains the criterion of symmetric instability in an adiabatic case.