Research is done on the robust stability of multi -delay differential systems of neutral type subject to norm -bounded parameter uncertainty that played important roles in the control theory.

The decentralization of sampled value and the uncertainty of sampled time bring forth the action fuzzy area of sampled value current differential protection.

When a differential pressure water - level gauge is used to measure the water - level in the vessel, large uncertainty can be induced because of the change of media density in the vessel.