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Learning deterministic regular grammars from stochastic samples in polynomial time

Rafael C. Carrasco, Jose Oncina (2010)

RAIRO - Theoretical Informatics and Applications

In this paper, the identification of stochastic regular languages is addressed. For this purpose, we propose a class of algorithms which allow for the identification of the structure of the minimal stochastic automaton generating the language. It is shown that the time needed grows only linearly with the size of the sample set and a measure of the complexity of the task is provided. Experimentally, our implementation proves very fast for application purposes.

Learning discrete categorial grammars from structures

Jérôme Besombes, Jean-Yves Marion (2008)

RAIRO - Theoretical Informatics and Applications

We define the class of discrete classical categorial grammars, similar in the spirit to the notion of reversible class of languages introduced by Angluin and Sakakibara. We show that the class of discrete classical categorial grammars is identifiable from positive structured examples. For this, we provide an original algorithm, which runs in quadratic time in the size of the examples. This work extends the previous results of Kanazawa. Indeed, in our work, several types can be associated to a word...

Learning extremal regulator implementation by a stochastic automaton and stochastic approximation theory

Ivan Brůha (1980)

Aplikace matematiky

There exist many different approaches to the investigation of the characteristics of learning system. These approaches use different branches of mathematics and, thus, obtain different results, some of them are too complicated and others do not match the results of practical experiments. This paper presents the modelling of learning systems by means of stochastic automate, mainly one particular model of a learning extremal regulator. The proof of convergence is based on Dvoretzky's Theorem on stochastic...

Learning from imprecise examples with GA-P algorithms.

Luciano Sánchez, Inés Couso (1998)

Mathware and Soft Computing

GA-P algorithms combine genetic programming and genetic algorithms to solve symbolic regression problems. In this work, we will learn a model by means of an interval GA-P procedure which can use precise or imprecise examples. This method provides us with an analytic expression that shows the dependence between input and output variables, using interval arithmetic. The method also provides us with interval estimations of the parameters on which this expression depends.The algorithm that we propose...

Learning fuzzy systems. An objective function-approach.

Frank Höppner, Frank Klawonn (2004)

Mathware and Soft Computing

One of the most important aspects of fuzzy systems is that they are easily understandable and interpretable. This property, however, does not come for free but poses some essential constraints on the parameters of a fuzzy system (like the linguistic terms), which are sometimes overlooked when learning fuzzy system autornatically from data. In this paper, an objective function-based approach to learn fuzzy systems is developed, taking these constraints explicitly into account. Starting from fuzzy...

Learning imprecise semantic concepts from image databases.

Daniel Sánchez, Jesús Chamorro-Martínez (2002)

Mathware and Soft Computing

In this paper we introduce a model to represent high-level semantic concepts that can be perceived in images. The concepts are learned and represented by means of a set of association rules that relate the presence of perceptual features to the fulfillment of a concept for a set of images. Since both the set of images where a perceptual feature appears and the set of images fulfilling a given concept are fuzzy, we use in fact fuzzy association rules for the learning model. The concepts so acquired...

Learning tree languages from text

Henning Fernau (2007)

RAIRO - Theoretical Informatics and Applications

We study the problem of learning regular tree languages from text. We show that the framework of function distinguishability, as introduced by the author in [Theoret. Comput. Sci.290 (2003) 1679–1711], can be generalized from the case of string languages towards tree languages. This provides a large source of identifiable classes of regular tree languages. Each of these classes can be characterized in various ways. Moreover, we present a generic inference algorithm with polynomial update time...

Least periods of factors of infinite words

James D. Currie, Kalle Saari (2009)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

We show that any positive integer is the least period of a factor of the Thue-Morse word. We also characterize the set of least periods of factors of a sturmian word. In particular, the corresponding set for the Fibonacci word is the set of Fibonacci numbers. As a by-product of our results, we give several new proofs and tightenings of well-known properties of sturmian words.

Least Periods of Factors of Infinite Words

James D. Currie, Kalle Saari (2008)

RAIRO - Theoretical Informatics and Applications

We show that any positive integer is the least period of a factor of the Thue-Morse word. We also characterize the set of least periods of factors of a Sturmian word. In particular, the corresponding set for the Fibonacci word is the set of Fibonacci numbers. As a by-product of our results, we give several new proofs and tightenings of well-known properties of Sturmian words.

L'Edif, un format estàndar per a l'intercanvi de dades de dissenys electrònics.

Salvador Mir, Xavier Mir, Josep Antoni Rubio (1987)

Qüestiió

En estos últimos años, el rápido incremento de los sistemas CAE/CAD en el campo de la electrónica ha hecho que la transferencia de información de unos sistemas a otros fuese un problema creciente. En consecuencia, se ha hecho necesaria una estandarización de los lenguajes de diseño y de los formatos de intercambio de datos. EDIF (Electronic Design Interchange Format) nace para responder a esta necesidad de estandarización.Este artículo describe la implementación de un reconocedor del formato EDIF...

Left-to-right regular languages and two-way restarting automata

Friedrich Otto (2009)

RAIRO - Theoretical Informatics and Applications

It is shown that the class of left-to-right regular languages coincides with the class of languages that are accepted by monotone deterministic RL-automata, in this way establishing a close correspondence between a classical parsing algorithm and a certain restricted type of analysis by reduction.

Les I -types du système ℱ

K. Nour (2001)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Nous démontrons dans ce papier que les types du système ℱ habités uniquement par des λ I -termes (les I -types) sont à quantificateur positif. Nous présentons ensuite des conséquenses de ce résultat et quelques exemples.

Les I-types du système ℱ

K. Nour (2010)

RAIRO - Theoretical Informatics and Applications

We prove in this paper that the types of system ℱ inhabited uniquely by λI-terms (the I-types) have a positive quantifier. We give also consequences of this result and some examples.

Les schémas mentaux : représenter et maintenir une connaissance apprise

Denis Pierre (1997)

Mathématiques et Sciences Humaines

Nous nous intéressons à l'apprentissage à partir d'exemples et à la résolution de problème dans un univers évolutif représenté par une base de connaissances incomplète. Nous formalisons un cadre de représentation de connaissances susceptible d'être élaboré et critiqué par des humains comme par des machines. Cette représentation des connaissances est appelée théorie semi-empirique car cette forme de théorie n'est pas complètement axiomatique. Nous avons formalisé la gestion de la croissance incrémentale...

Les Symétries dans les Réseaux de Petri Stochastiques (RdPS) Construction du Graphe Symbolique

M. Ioualalen, A. Aissani (2010)

RAIRO - Operations Research

The main purpose of this paper is to give a method for construction of the reduced reachability graph for Stochastic Petri Nets (SPN), the symbolic graph. This construction is achieved by exploiting the structural symetries in the net using the theory of bisimulation of places for detecting isomorphic parts in the net. The symbolic graph, being isomorphic to an agregated Markov chain, may be used to prove qualitative properties as liveness, boundness, ... Moreover, this reduced graph make more...

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