Multidimensional access methods are considered to be a promising approach for providing acceptable performance to analysis-centric applications. However, despite the large body of research work in this field, the commercial support for multidimensional indexes is still very weak. The reason for this discrepancy is threefold: first, no standard multidimensional index like the B-Tree for one-dime...

Abstract We study the portraits of isometries rooted trees—the labelling tree, at each vertex, by permutation its descendants—in terms languages. characterize regularly branched self-similar groups in $$\omega $$ ω -regular deduce algorithmic decidability some problems, such as comparison contracting groups, ...

Automata theory plays a key role in computational theory as many computational problems can be solved with its help. Formal grammar is a special type of automata designed for linguistic purposes. Formal grammar generates formal languages. Rough grammar and rough languages were introduced to incorporate the imprecision of real languages in formal languages. These languages have limitations on un...

A fuzzy multidimensional model can be use for exploratory analysis, modelling complex concepts that are very difficult to use in crisp ones. Some problems, as the edge problem, can we reduce using this approach. To hide the complexity of the fuzzy logic in this situation is important. In this paper we present an application of a fuzzy multidimensional model, that uses two layer representation t...

A fuzzy multidimensional model can be used for exploratory analysis, modelling complex concepts that are very difficult to use in crisp ones. Some problems, as the edge problem, can be reduced using this approach. To hide the complexity of the fuzzy logic in this situation is important. In this paper we present an application of a fuzzy multidimensional model, that uses two layer representation...

A fuzzy multidimensional model can be used for exploratory analysis, modelling complex concepts that are very difficult to use in crisp ones. Some problems, as the edge problem, can be reduced using this approach. To hide the complexity of the fuzzy logic in this situation is important. In this paper we present an application of a fuzzy multidimensional model, that uses two layer representation...

introduction: virtual bronchoscopy is a reliable and efficient diagnostic method for primary symptoms of lung cancer. the segmentation of airways from ct images is a critical step for numerous virtual bronchoscopy applications. materials and methods: to overcome the limitations of the fuzzy connectedness method, the proposed technique, called fuzzy connectivity - fuzzy c-mean (fc-fcm), utilized...

Myhill-Nerode Theorem is regarded as a basic theorem in the theories of languages and automata and is used to prove the equivalence between automata and their languages. The significance of this theorem has stimulated researchers to develop that on different automata thus leading to optimizing computational models. In this article, we aim at developing the concept of congruence in general fuzzy...

In this paper, we study multidimensional integrals. We introduce a generalized fuzzy integral and we present a Fubini-like theorem for this generalized fuzzy integral. As this research was partly motivated by the definition of citation indices, we also describe how such multidimensional integrals can be used to define such indices. © 2008 Elsevier B.V. All rights reserved.