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Fast String Correction with LevenshteinAutomata
 INTERNATIONAL JOURNAL OF DOCUMENT ANALYSIS AND RECOGNITION
, 2002
"... The Levenshteindistance between two words is the minimal number of insertions, deletions or substitutions that are needed to transform one word into the other. Levenshteinautomata of degree n for a word W are defined as finite state automata that regognize the set of all words V where the Levensht ..."
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Cited by 27 (4 self)
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The Levenshteindistance between two words is the minimal number of insertions, deletions or substitutions that are needed to transform one word into the other. Levenshteinautomata of degree n for a word W are defined as finite state automata that regognize the set of all words V where the Levenshteindistance between V and W does not exceed n. We show how to compute, for any fixed bound n and any input word W , a deterministic Levenshteinautomaton of degree n for W in time linear in the length of W . Given an electronic dictionary that is implemented in the form of a trie or a finite state automaton, the Levenshteinautomaton for W can be used to control search in the lexicon in such a way that exactly the lexical words V are generated where the Levenshteindistance between V and W does not exceed the given bound. This leads to a very fast method for correcting corrupted input words of unrestricted text using large electronic dictionaries. We then introduce a second method that avoids the explicit computation of Levenshteinautomata and leads to even improved eciency. We also describe how to extend both methods to variants of the Levenshteindistance where further primitive edit operations (transpositions, merges and splits) may be used.
Comparison of Construction Algorithms for Minimal, Acyclic, Deterministic, FiniteState Automata from Sets of Strings
"... This paper compares various methods for constructing minimal, deterministic, acyclic, nitestate automata from sets of words. ..."
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Cited by 7 (0 self)
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This paper compares various methods for constructing minimal, deterministic, acyclic, nitestate automata from sets of words.
Experiments with Automata Compression
, 2000
"... Several compression methods of finitestate automata are presented and evaluated. Most compression methods used here are already described in the literature. However, their impact on the size of automata has not been described yet. We fill that gap, presenting results of experiments carried out on a ..."
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Cited by 5 (3 self)
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Several compression methods of finitestate automata are presented and evaluated. Most compression methods used here are already described in the literature. However, their impact on the size of automata has not been described yet. We fill that gap, presenting results of experiments carried out on automata representing German, and Dutch morphological dictionaries.
How to Squeeze a Lexicon
 Software Practice and Experience
, 2000
"... Minimal acyclic deterministic finite automata (ADFAs) can be used as a compact representation of string sets with fast access time. Creating them with traditional algorithms of DFA minimization is a resource hog when a large number of strings is involved. This paper aims to popularize an efficient b ..."
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Cited by 3 (1 self)
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Minimal acyclic deterministic finite automata (ADFAs) can be used as a compact representation of string sets with fast access time. Creating them with traditional algorithms of DFA minimization is a resource hog when a large number of strings is involved. This paper aims to popularize an efficient but little known algorithm for creating minimal ADFAs recognizing a finite language, developed independently by several authors. The algorithm is presented for three variants of ADFAs, its minor improvements are discussed, and minimal ADFAs are compared to competitive data structures.
Finite State Tools for Natural Language Processing
, 2000
"... We describe a set of tools using deterministic, acyclic, finitestate automata for natural language processing applications. The core of the tool set consists of two programs constructing finitestate automata (using two different, but related algorithms). Other programs from the set interpret the c ..."
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Cited by 1 (0 self)
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We describe a set of tools using deterministic, acyclic, finitestate automata for natural language processing applications. The core of the tool set consists of two programs constructing finitestate automata (using two different, but related algorithms). Other programs from the set interpret the contents of those automata. Preprocessing scripts and user interfaces complete the set. 1 Introduction Finitestate automata (both acceptors and transducers) play increasingly important role in natural language processing. Deterministic, acyclic, finitestate automata are used mainly as representations of various kinds of dictionaries. Their main advantages are their small size as compared with the data they hold (see e.g. [3]), and the very fast lookup of strings in an automaton (proportional to the length of the string). Deterministic, acyclic, finitestate automata (DAFSA) are used in a variety of applications, including DNA sequencing, computer virus detection, and VLSA design. In natu...
FA Minimization heuristics for a class of finite languages
"... . In this paper, we deal with minimization of nite automata associated with nite languages all the words have the same length. This problem arises in the context of Constraint Satisfaction Problems, widely used in AI. We rst give some complexity results which are based on the strong relationship wit ..."
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. In this paper, we deal with minimization of nite automata associated with nite languages all the words have the same length. This problem arises in the context of Constraint Satisfaction Problems, widely used in AI. We rst give some complexity results which are based on the strong relationship with covering problems of bipartite graphs. We then use these coverings as a basic tool for the denition of minimization heuristics, and describe some experimental results. 1 Motivations Many AI problems can be expressed as Constraint Satisfaction Problems or CSP for short [Mon74]. A CSP involves a nite set of variables, a nite set of values for the variables and a set of constraints. Each constraint is dened as a relation on some subset of variables and gives the values which are mutually compatible for these variables. A solution is a value assignment to variables that satisfy all the constraints. Most of the CSP's works deal with the problem of computing one solution. Nevertheless, i...