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Comparing the succinctness of monadic query languages over finite trees

Martin Grohe, Nicole Schweikardt (2010)

RAIRO - Theoretical Informatics and Applications

We study the succinctness of monadic second-order logic and a variety of monadic fixed point logics on trees. All these languages are known to have the same expressive power on trees, but some can express the same queries much more succinctly than others. For example, we show that, under some complexity theoretic assumption, monadic second-order logic is non-elementarily more succinct than monadic least fixed point logic, which in turn is non-elementarily more succinct than monadic datalog.
Succinctness...

Data mining techniques using decision tree model in materialised projection and selection view.

Y. W. Teh (2004)

Mathware and Soft Computing

With the availability of very large data storage today, redundant data structures are no longer a big issue. However, an intelligent way of managing materialised projection and selection views that can lead to fast access of data is the central issue dealt with in this paper. A set of implementation steps for the data warehouse administrators or decision makers to improve the response time of queries is also defined. The study concludes that both attributes and tuples, are important factors to be...

Formalization of Provenes fuzzy functional dependency in fuzzy databases.

Nedzad Dukic, Zikrija Avdagic (2004)

Mathware and Soft Computing

In this paper we establish equivalence between a theory of fuzzy functional dependences and a fragment of fuzzy logic. We give a way to interpret fuzzy functional dependences as formulas in fuzzy logic. This goal is realized in a few steps. Truth assignment of attributes is defined in terms of closeness between two tuples in a fuzzy relation. A corresponding fuzzy formula is associated to a fuzzy functional dependence. It is proved that if a relation satisfies a fuzzy functional dependence, then...

Fuzzy adaptation for information access to digital libraries.

Camino Fernández, Ignacio Aedo, Paloma Díaz, Vicente Matellán (2000)

Mathware and Soft Computing

Different models have been proposed to build systems that adapt to the user reducing the complexity in the information browsing process, saving user time and offering personalised interfaces. The work described in this paper named WAY-Z39.50, is an example of adaptive system specially built for accessing digital libraries. A fuzzy decision mechanism is used to implement the adaptation of both the user interface and the information searching process. This paper describes how this system has been...

Fuzzy clustering: Insights and new approach.

Frank Klawonn (2004)

Mathware and Soft Computing

Fuzzy clustering extends crisp clustering in the sense that objects can belong to various clusters with different membership degrees at the same time, whereas crisp or deterministic clustering assigns each object to a unique cluster. The standard approach to fuzzy clustering introduces the so-called fuzzifier which controls how much clusters may overlap. In this paper we illustrate, how this fuzzifier can help to reduce the number of undesired local minima of the objective function that is associated...

Fuzzy decision trees to help flexible querying

Christophe Marsala (2000)

Kybernetika

Fuzzy data mining by means of the fuzzy decision tree method enables the construction of a set of fuzzy rules. Such a rule set can be associated with a database as a knowledge base that can be used to help answering frequent queries. In this paper, a study is done that enables us to show that classification by means of a fuzzy decision tree is equivalent to the generalized modus ponens. Moreover, it is shown that the decision taken by means of a fuzzy decision tree is more stable when observation...

Inf-datalog, modal logic and complexities

Eugénie Foustoucos, Irène Guessarian (2009)

RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications

Inf-Datalog extends the usual least fixpoint semantics of Datalog with greatest fixpoint semantics: we defined inf-Datalog and characterized the expressive power of various fragments of inf-Datalog in [16]. In the present paper, we study the complexity of query evaluation on finite models for (various fragments of) inf-Datalog. We deduce a unified and elementary proof that global model-checking (i.e. computing all nodes satisfying a formula in a given structure) has 1. quadratic data complexity...

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