Showing papers on "Chomsky hierarchy published in 1992"
TL;DR: It is pointed out that EFS can also work as a logic programming language, and the resolution procedure for EFSCan be used to accept languages, and Shapiro's theory of model inference can naturally be applied to language learning by EFS.
77 citations
01 Jan 1992
TL;DR: A unifying framework of syntactic and statistical pattern recognition for one-dimensional observations and signals like speech is presented and it will be shown how these techniques can be applied to the task of continuous speech recognition.
Abstract: This paper presents a unifying framework of syntactic and statistical pattern recognition for one-dimensional observations and signals like speech. The syntactic constraints will be based upon stochastic extensions of the grammars in the Chomsky hierarchy. These extended stochastic grammars can be applied to both discrete and continuous observations. Neglecting the mathematical details and complications, we can convert a grammar of the Chomsky hierarchy to a stochastic grammar by attaching probabilities to the grammar rules and, for continuous observations, attaching probability density functions to the terminals of the grammar. In such a framework, a consistent integration of syntactic pattern recognition and statistical pattern recognition, which is typically based upon Bayes’ decision rule for minimum error rate, can be achieved such that no error correction or postprocessing after the recognition phase is required. Efficient algorithms and closed-form solutions for the parsing and recognition problem will be presented for the following types of stochastic grammars: regular, linear and context-free. It will be shown how these techniques can be applied to the task of continuous speech recognition.
73 citations
TL;DR: This paper gives a progression of automata and shows that it corresponds exactly to the language hierarchy defined with control grammars, the first member of which is context-free languages.
63 citations
TL;DR: A mathematical definition of left-associative grammar is presented, and its formal properties are described, in contrast to more traditional systems such as phrase structure grammar and categorial grammar, which are linguistically motivated in terms of possible substitutions.
48 citations
Proceedings Article•
30 Nov 1992TL;DR: Here it is shown that formal languages too can be specified by Harmonic Grammars, rather than by conventional serial rewrite rule systems.
Abstract: Basic connectionist principles imply that grammars should take the form of systems of parallel soft constraints defining an optimization problem the solutions to which are the well-formed structures in the language. Such Harmonic Grammars have been successfully applied to a number of problems in the theory of natural languages. Here it is shown that formal languages too can be specified by Harmonic Grammars, rather than by conventional serial rewrite rule systems.
9 citations
TL;DR: Sakakibara [4] has shown that if the authors allow structural membership queries and structural equivalence queries, then the whole class of context-free grammars can be inferred, and there exists an algorithm which uses positive structural data only.
7 citations
30 Aug 1992
TL;DR: In this paper, for several formal languages (of various types) the equivalent transformation systems are presented and it can be drawn that the transformation systems give shorter and more informative structural class descriptions than the formal grammars.
Abstract: The concept of the transformation system was introduced earlier by the author as a basic part of a general model for pattern learning. In this paper, for several formal languages (of various types) the equivalent transformation systems are presented. From these examples one can draw the conclusion that the transformation systems give shorter and more informative structural class descriptions than the formal grammars. >
3 citations
TL;DR: A formal model for three-dimensional object representation is introduced that uses parallel techniques and significantly reduces the time required for dealing with three- dimensional image analysis problems.
Abstract: A formal model for three-dimensional object representation is introduced. It uses parallel techniques and significantly reduces the time required for dealing with three-dimensional image analysis problems. Its fundamental properties are investigated and several interesting examples are illustrated.
1 citations
Journal Article•
TL;DR: The problem proposed by Gauss of characterizing the code of a simple crossing closed curve (SCCC) can be considered a formal language question and three related infinite languages are defined.
Abstract: The problem proposed by Gauss of characterizing the code of a simple crossing closed curve (SCCC, for short) can be considered a formal language question. We define three related infinite languages. Two of them are regular; the type of the third is an open problem.
1 citations
15 Sep 1992
TL;DR: This paper presents a formal model of hierarchical visual languages, called HIRG (hierarchical icon-replacement grammar), which is then extended to enable the integration of textual and visual notations.
Abstract: Addresses the issue of the formal definition of hierarchical visual languages. It is motivated by interest in formal system development and the use of visual languages as formal specification tools. The paper presents a formal model of hierarchical visual languages. This model, called HIRG (hierarchical icon-replacement grammar), is then extended to enable the integration of textual and visual notations. >