The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform

Solon P. Pissis - One of the best experts on this subject based on the ideXlab platform.

  • Computing all subtree repeats in ordered trees
    Information Processing Letters, 2012
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of computing all subtree repeats in a given labeled ordered tree. We first transform the tree to a string representing its Postfix Notation, and then present an algorithm based on the bottom-up technique to solve it. The proposed algorithm consists of two phases: the preprocessing phase and the phase where all subtree repeats are computed. The linear time and space complexity of the proposed algorithm are important parts of its quality.

  • Tree template matching in ranked ordered trees by pushdown automata
    Journal of Discrete Algorithms, 2012
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the worst case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • SPIRE - Computing all subtree repeats in ordered ranked trees
    String Processing and Information Retrieval, 2011
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of finding all subtree repeats in a given ordered ranked tree. Specifically, we transform the given tree to a string representing its Postfix Notation, and then propose an algorithm based on the bottom-up technique. The proposed algorithm is divided into two phases: the preprocessing phase, and the phase where all subtree repeats are computed. The linear runtime of the algorithm, as well as the use of linear auxiliary space, are important aspects of its quality.

  • CIAA - Tree template matching in ranked ordered trees by pushdown automata
    Implementation and Application of Automata, 2011
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the general case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

Tomas Flouri - One of the best experts on this subject based on the ideXlab platform.

  • Computing all subtree repeats in ordered trees
    Information Processing Letters, 2012
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of computing all subtree repeats in a given labeled ordered tree. We first transform the tree to a string representing its Postfix Notation, and then present an algorithm based on the bottom-up technique to solve it. The proposed algorithm consists of two phases: the preprocessing phase and the phase where all subtree repeats are computed. The linear time and space complexity of the proposed algorithm are important parts of its quality.

  • Tree template matching in ranked ordered trees by pushdown automata
    Journal of Discrete Algorithms, 2012
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the worst case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • SPIRE - Computing all subtree repeats in ordered ranked trees
    String Processing and Information Retrieval, 2011
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of finding all subtree repeats in a given ordered ranked tree. Specifically, we transform the given tree to a string representing its Postfix Notation, and then propose an algorithm based on the bottom-up technique. The proposed algorithm is divided into two phases: the preprocessing phase, and the phase where all subtree repeats are computed. The linear runtime of the algorithm, as well as the use of linear auxiliary space, are important aspects of its quality.

  • CIAA - Tree template matching in ranked ordered trees by pushdown automata
    Implementation and Application of Automata, 2011
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the general case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • Subtree matching by pushdown automata
    Computer Science and Information Systems, 2010
    Co-Authors: Tomas Flouri, Jan Janousek, Bořivoj Melichar
    Abstract:

    Subtree matching is an important problem in Computer Science on which a number of tasks, such as mechanical theorem proving, term-rewriting, symbolic computation and nonprocedural programming languages are based on. A systematic approach to the construction of subtree pattern matchers by deterministic pushdown automata, which read subject trees in prefix and Postfix Notation, is presented. The method is analogous to the construction of string pattern matchers: for a given pattern, a nondeterministic pushdown automaton is created and is then determinised. In addition, it is shown that the size of the resulting deterministic pushdown automata directly corresponds to the size of the existing string pattern matchers based on finite automata.

Bořivoj Melichar - One of the best experts on this subject based on the ideXlab platform.

  • Computing all subtree repeats in ordered trees
    Information Processing Letters, 2012
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of computing all subtree repeats in a given labeled ordered tree. We first transform the tree to a string representing its Postfix Notation, and then present an algorithm based on the bottom-up technique to solve it. The proposed algorithm consists of two phases: the preprocessing phase and the phase where all subtree repeats are computed. The linear time and space complexity of the proposed algorithm are important parts of its quality.

  • Tree template matching in ranked ordered trees by pushdown automata
    Journal of Discrete Algorithms, 2012
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the worst case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • SPIRE - Computing all subtree repeats in ordered ranked trees
    String Processing and Information Retrieval, 2011
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of finding all subtree repeats in a given ordered ranked tree. Specifically, we transform the given tree to a string representing its Postfix Notation, and then propose an algorithm based on the bottom-up technique. The proposed algorithm is divided into two phases: the preprocessing phase, and the phase where all subtree repeats are computed. The linear runtime of the algorithm, as well as the use of linear auxiliary space, are important aspects of its quality.

  • CIAA - Tree template matching in ranked ordered trees by pushdown automata
    Implementation and Application of Automata, 2011
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the general case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • Subtree matching by pushdown automata
    Computer Science and Information Systems, 2010
    Co-Authors: Tomas Flouri, Jan Janousek, Bořivoj Melichar
    Abstract:

    Subtree matching is an important problem in Computer Science on which a number of tasks, such as mechanical theorem proving, term-rewriting, symbolic computation and nonprocedural programming languages are based on. A systematic approach to the construction of subtree pattern matchers by deterministic pushdown automata, which read subject trees in prefix and Postfix Notation, is presented. The method is analogous to the construction of string pattern matchers: for a given pattern, a nondeterministic pushdown automaton is created and is then determinised. In addition, it is shown that the size of the resulting deterministic pushdown automata directly corresponds to the size of the existing string pattern matchers based on finite automata.

Jan Janousek - One of the best experts on this subject based on the ideXlab platform.

  • Computing all subtree repeats in ordered trees
    Information Processing Letters, 2012
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of computing all subtree repeats in a given labeled ordered tree. We first transform the tree to a string representing its Postfix Notation, and then present an algorithm based on the bottom-up technique to solve it. The proposed algorithm consists of two phases: the preprocessing phase and the phase where all subtree repeats are computed. The linear time and space complexity of the proposed algorithm are important parts of its quality.

  • Tree template matching in ranked ordered trees by pushdown automata
    Journal of Discrete Algorithms, 2012
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the worst case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • SPIRE - Computing all subtree repeats in ordered ranked trees
    String Processing and Information Retrieval, 2011
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of finding all subtree repeats in a given ordered ranked tree. Specifically, we transform the given tree to a string representing its Postfix Notation, and then propose an algorithm based on the bottom-up technique. The proposed algorithm is divided into two phases: the preprocessing phase, and the phase where all subtree repeats are computed. The linear runtime of the algorithm, as well as the use of linear auxiliary space, are important aspects of its quality.

  • CIAA - Tree template matching in ranked ordered trees by pushdown automata
    Implementation and Application of Automata, 2011
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the general case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • Subtree matching by pushdown automata
    Computer Science and Information Systems, 2010
    Co-Authors: Tomas Flouri, Jan Janousek, Bořivoj Melichar
    Abstract:

    Subtree matching is an important problem in Computer Science on which a number of tasks, such as mechanical theorem proving, term-rewriting, symbolic computation and nonprocedural programming languages are based on. A systematic approach to the construction of subtree pattern matchers by deterministic pushdown automata, which read subject trees in prefix and Postfix Notation, is presented. The method is analogous to the construction of string pattern matchers: for a given pattern, a nondeterministic pushdown automaton is created and is then determinised. In addition, it is shown that the size of the resulting deterministic pushdown automata directly corresponds to the size of the existing string pattern matchers based on finite automata.

Costas S. Iliopoulos - One of the best experts on this subject based on the ideXlab platform.

  • Computing all subtree repeats in ordered trees
    Information Processing Letters, 2012
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of computing all subtree repeats in a given labeled ordered tree. We first transform the tree to a string representing its Postfix Notation, and then present an algorithm based on the bottom-up technique to solve it. The proposed algorithm consists of two phases: the preprocessing phase and the phase where all subtree repeats are computed. The linear time and space complexity of the proposed algorithm are important parts of its quality.

  • Tree template matching in ranked ordered trees by pushdown automata
    Journal of Discrete Algorithms, 2012
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the worst case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.

  • SPIRE - Computing all subtree repeats in ordered ranked trees
    String Processing and Information Retrieval, 2011
    Co-Authors: Michalis Christou, Maxime Crochemore, Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of finding all subtree repeats in a given ordered ranked tree. Specifically, we transform the given tree to a string representing its Postfix Notation, and then propose an algorithm based on the bottom-up technique. The proposed algorithm is divided into two phases: the preprocessing phase, and the phase where all subtree repeats are computed. The linear runtime of the algorithm, as well as the use of linear auxiliary space, are important aspects of its quality.

  • CIAA - Tree template matching in ranked ordered trees by pushdown automata
    Implementation and Application of Automata, 2011
    Co-Authors: Tomas Flouri, Costas S. Iliopoulos, Jan Janousek, Bořivoj Melichar, Solon P. Pissis
    Abstract:

    We consider the problem of tree template matching in ranked ordered trees, and propose a solution based on the bottom-up technique. Specifically, we transform the tree pattern matching problem to a string matching problem, by transforming the tree template and the subject tree to strings representing their Postfix Notation, and then use pushdown automata as the computational model. The method is analogous to the construction of string pattern matchers. The given tree template is preprocessed once, by constructing a nondeterministic pushdown automaton, which is then transformed to the equivalent deterministic one. Although we prove that the space required for preprocessing is exponential to the size of the tree template in the general case, the space required for a specific class of tree templates is linear. The time required for the searching phase is linear to the size of the subject tree in both cases.