On real time and linear time cellular automata
We address the problem of computing the capacity of a covert channel, modeled as a nondeterministic transducer. We give three possible statements of the notion of “covert channel capacity” and relate the different definitions. We then provide several methods allowing the computation of lower and upper bounds for the capacity of a channel. We show that, in some cases, including the case of input-deterministic channels, the capacity of the channel can be computed exactly (e.g. in the form...
This paper establishes computational equivalence of two seemingly unrelated concepts: linear conjunctive grammars and trellis automata. Trellis automata, also studied under the name of one-way real-time cellular automata, have been known since early 1980s as a purely abstract model of parallel computers, while linear conjunctive grammars, introduced a few years ago, are linear context-free grammars extended with an explicit intersection operation. Their equivalence implies the equivalence of several...
This paper establishes computational equivalence of two seemingly unrelated concepts: linear conjunctive grammars and trellis automata. Trellis automata, also studied under the name of one-way real-time cellular automata, have been known since early 1980s as a purely abstract model of parallel computers, while linear conjunctive grammars, introduced a few years ago, are linear context-free grammars extended with an explicit intersection operation. Their equivalence implies the equivalence of several...