On K-Positivity Properties of Time-Invariant Linear Systems Subject to Discrete Point Lags

This paper discusses non-negativity and positivity concepts and related properties for the state and output trajectory solutions of dynamic linear time-invariant systems described by functional differential equations subject to point time-delays. The various non-negativity and positivity introduced hierarchically from the weakest one to the strongest one while separating the corresponding properties when applied to the state space or to the output space as well as for the zero-initial state or zero-input responses. The formulation is developed by defining cones for the input, state and output spaces of the dynamic system.