Servomechanisms and Regulating System Design: Vol. II

The Mechanism of Cheyne-Stokes Respiration*

“…A similar electrical system would be considered to have positive feedback and greater than unity gain. Both systems would oscillate at a frequency-related to the time required for a complete circuit (12,13). By such an analogy C-S respiration would occur whenever the damping factors (FRC, alkaline reserve, short lung-to-brain transit time) are sufficiently compromised.…”

“…Because of the finite time required for transmission of feedback and the greater than unity gain, the system as described would be unstable at certain frequencies and would result in oscillating fluctuations in ventilatory activity (12,13). Several stabilizing mechanisms operate.…”

“…When the amplifier component of a system acts in such a manner that a disturbing influence (input) results in a response (output) which, in the absence of a feedback signal would be greater in magnitude than the input, then the ratio of output to input will exceed one, and the gain becomes some value greater than unity. In general, a high gain amplifier component in a control system acts to provide rapid response to changing conditions as well as close adherence to a reference input value (12,13). The respiratory control system responds to an increase in Pco2 by increasing ventilation and lowering the PCo2 of pulmonary capillary blood.…”

A New Approach to Temperature Shift Functions in Modeling Complex Modulus Damping Data

“…With reference to Eqn 4, an equation useful for the present purpose is [9] ( ) ( ) (6) An element of viscoelastic material may be considered to be a linear system with input of stress and output of strain or vise versa and the complex modulus is a FRF. By examining Eqn 4, it may be seen that…”

Adaptive Control of Nuclear Reactors Using a Digital Computer

“…The traditional approach to control system design has been to develop the transfer function of the plant, and use such frequency domain techniques as Nyquist or Bode plots, or Nichols charts, [5] to synthesi~e the necessary compensating networks that will ensure the desired response in the time-domain. With the advent of digital computers, interest has returned to the more direct method of working only in the time-domain [6].…”