It is well-known that exponential stabilization of a neutral system with unstable diierence operator is only possible by allowing for control laws containing derivative feedback. We show that closed-loop stability of a neutral system with unstable open-loop diierence operator obtained by applying a derivative feedback scheme is extremely sensitive to arbitrarily small time-delays in the feedbac...

Two-circuit models for feedback subcircuits are developed from a modification to the two-port method of feedback amplifier analysis and are applied in a method to break the feedback loop. These models are terminally equivalent to linear and nonlinear subcircuits, have physically-disconnected topologies, and employ dependent sources to control lateral signal transfer with a switch-like on or off...

To analyze the contribution of each element in a sensory feedback control system, it is necessary to study the system with the feedback loop opened. Some physiological systems have multiple or even unknown sources of feedback, which makes it exceedingly difficult to open the loop. Conversely, it is relatively easy to open the loop on the human eye-movement system. Study of this system should he...