Showing papers on "Pushdown automaton published in 1980"

The mathematical theory of L systems

Abstract: The paper gives a survey of the different areas of the theory of developmental systems and languages. It is organized in such a way that it discusses typical results obtained in each particular problem area. The results quoted may not always be the most important ones but they are quite representative for the direction of research in this theory. Proofs are not given and, consequently, the basic techniques for solving problems in this theory are not discussed. An attempt has been made to cover also the most recent results. Most of the results have not yet appeared in print. To appear in J. Tou (ed. ), Advances in Information Systems Science, Plenum Press.

The equivalence problem for real-time strict deterministic languages

Abstract: The equivalence problem is decidable for deterministic real-time pushdown store automata accepting by empty stack. Further, the equivalence problem is decidable for two deterministic pushdown store automata, one of which is real-time accepting by empty stack.

A Real-Time Strictness Test for Deterministic Pushdown Automata*

Abstract: A context-free language is said to be real-time strict if it is accepted by a real-time deterministic pushdown automaton with empty stack acceptance. This paper proves that there exists an effective procedure for deciding whether the language accepted by a deterministic pushdown automaton (dpda) is real-time strict. The result implies the following: For any subclass ℰ of real-time dpda's with empty stack acceptance, the problem for deciding whether a dpda is equivalent to some machine in ℰ reduces to that for deciding whether a real-time dpda with empty stack acceptance is equivalent to some machine in ℰ.

Semi-group, group quotient and homogeneous automata

Abstract: Every cyclic automaton is isomorphic to a semi-group quotient automaton, while for a homogeneous automaton the semi-group may be replaced by a group. The connection between this isomorphism and the inertial relation on the state-space is explored, leading to more general statements. For example, a pseudo-homogeneous automaton is pseudo-isomorphic to a group-quotient automaton.

Models for the color continuum and subsets thereof

Abstract: Computer generation of color patterns, has revived interest in various classical models for color distribution (triangular, circular, pyramidal, conical, spherical etc.). The oldest model is the color spectrum displayed in the heavens by the rainbow: heme frequencies of the refracted visible light determine the color variations. Newton, by observing sunlight passing through a prism developed a down to earth model to demonstrate colors obtained by separating white light into its components. The properties of colors generated by combining primary colored lights (the additive system with primary components, red, green, and blue) were discovered to be different from those in the subtractive system of pigments where reflected light has colors filtered out by pigment combinations used. Here, the primary colors ape cyan, magenta and yellow, respectively. The author will display dual models generated on the Intecolor 8051 for these two systems. I In the additive model, 000 is assigned to black, the console color when no light is present and ill is assigned to white, where the three primaries are supplied in equal strength. In the subtractive system, 000 is assigned to white for the fully reflective surface and Ill, to black which is obtained by filtering with all three pigments covering the white base. The table below shows the duality between the systems. Lights On Additive Binary Notation Subtract&ve Colors Filtered Out none null black 000 white null none red only primary red 001 cyan pmimary red filtered out green only primary green 010 magenta primary green filtered out red E green secondary yellow 0il blue secondary red & green out blue primary blue I00 yellow primary blue filtered out blue % red secondary magenta I01 green secondary red & blue out blue & green secondary eyan II0 red secondary green ~ blue out all universe white III black universe all filtered out The interpretations of this model are as follows. In the additive system, the binary numbers show which of the blue, green or red light guns are turned on to produce the desired light status on a black cathode ray tube screen. In the subtractive system, the three digits from left to right tell you which additive primary colors are filtered out in the pigments combined to produce color reflections when applied to a white reflecting canvas. The author has been concerned with the use of color as the third dimension in displaying properties of mathematical functions, inequalities, …

A simplicity test for deterministic pushdown automata

Abstract: A context-free language is said to be simple if it is accepted by a single-state deterministic pushdown automaton with empty stack acceptance. This paper proves that it is decidable whether a deterministic pushdown automaton (dpda) accepts a simple language. For this purpose, we prove that it is decidable whether a real-time dpda with empty stack acceptance accepts a simple language. To prove this, we present two conditions called nonsingularity and separability conditions and show that for a real-time dpda M with empty stack acceptance, (i) the language accepted by M is simple if and only if M satisfies the two conditions, and (ii) it is decidable whether M satisfies the two conditions.