A long-standing open conceptual problem has been the following: How does "information" interact with control of a system, in particular feedback control, and what is the value of "information" in achieving performance objectives for the system through the exercise of control? In answering this question we have to remember that in contrast to a variety of communications settings, the issue of time-delay is of primary importance for control problems, especially control of systems which are unstable. We discuss various issues arising from these fundamental questions. A long-standing open conceptual problem has been the follow- Duality of a Source and a Channel. There is a curious and provocative duality between the properties of a source with a distortion measure and those of a channel. This duality is enhanced if we consider channels in which there is a "cost" associated with the difference input letters, and it is desired to find the capacity subject to the constraint that the expected cost not exceed a certain quantity. Thus input letter i might have cost a i and we wish to find the capacity with the side condition i P i a i ≤ a i , say, where P i is the probability of using input letter i. One of the many fundamental contributions which Shannon made which in fact renders the enunciation of the Noisy Channel Coding Theorem possible, is to think "digitally" (to use the work of a modern sage of Media technology), that is, to reduce everything to bits, a common currency in which everything can be evaluated. As we shall see late whether all bits are identical is an issue that we will have to face when dealing with the development of an Information Theory for sources which are decidedly non-stationary and non-ergodic. A corresponding all embracing theory for control in the presence of uncertainty does not exist. The issue of fundamental limitation is far more complicated here since it is unclear that the dynamical systems which we wish to modify to behave in prescribed ways through control can be characterized through
The need of a unified theory of control and information in the case of dynamic systems is underlined in the overview of REF , where the author discusses topics related to the control of systems with limited information.
Control With Limited Information
Eur. J. Control
Eur. J. Control
Computer Science