History
FD-DEVS was originally named as ``Schedule-Controlable DEVS`` and designed to support verification analysis of its networks which had been an open problem of DEVS formalism for 30 years. In addition, it was also designated to resolve the so-called ``OPNA`` problem of SP-DEVS. From the viewpoint of Classic DEVS, FD-DEVS has three restrictions
- finiteness of event sets and state set,
- the lifespan of a state can be scheduled by a rational number or infinity, and
- the internal schedule can be either preserved or updated by an input event.
The third restriction can be also seen as a relaxation from SP-DEVS where the schedule is always preserved by any input events. Due to this relaxation there is no longer OPNA problem, but there is also one limitation that a time-line abstraction which can be used for abstracting elapsed times of SP-DEVS networks is no longer useful for FD-DEVS network . But another time abstraction method which was invented by Prof. D. Dill can be applicable to obtain a finite-vertex reachability graph for FD-DEVS networks.
Read more about this topic: Finite & Deterministic Discrete Event System Specification
Famous quotes containing the word history:
“Free from public debt, at peace with all the world, and with no complicated interests to consult in our intercourse with foreign powers, the present may be hailed as the epoch in our history the most favorable for the settlement of those principles in our domestic policy which shall be best calculated to give stability to our Republic and secure the blessings of freedom to our citizens.”
—Andrew Jackson (1767–1845)
“Social history might be defined negatively as the history of a people with the politics left out.”
—G.M. (George Macaulay)
“The history of the world is none other than the progress of the consciousness of freedom.”
—Georg Wilhelm Friedrich Hegel (1770–1831)