Search results for "Transitive set"

showing 2 items of 2 documents

Perturbations of the derivative along periodic orbits

2006

International audience; We show that a periodic orbit of large period of a diffeomorphism or flow, either admits a dominated splitting of a prescribed strength, or can be turned into a sink or a source by a C1-small perturbation along the orbit. As a consequence we show that the linear Poincaré flow of a C1-vector field admits a dominated splitting over any robustly transitive set.

Applied MathematicsGeneral Mathematics[MATH.MATH-DS]Mathematics [math]/Dynamical Systems [math.DS]010102 general mathematicsMathematical analysis[ MATH.MATH-DS ] Mathematics [math]/Dynamical Systems [math.DS][MATH.MATH-DS] Mathematics [math]/Dynamical Systems [math.DS]Transitive set16. Peace & justice01 natural sciences37D30 (34C25 34D10 37C05 37C10 37C27)010101 applied mathematicsPeriodic orbitsVector fieldDiffeomorphism0101 mathematicsMathematics
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A generalized transitive closure for relational queries

1988

We augment relational algebra with a generalized transitive closure operator that allows for the efficient evaluation of a subclass of recursive queries. The operator is based on a composition operator which is as general as possible when the operator is required to be associative and when only relational algebra operators are used in its definition. The closure of such a composition can be computed using the well-known efficient algorithms designed for the computation of the usual transitive closure. Besides the case in which complete materialization of recursive relations are required, our strategy also yields an efficient solution in the case in which a selection is applied to the closur…

Transitive relationSelection (relational algebra)Closure (topology)Transitive closure020207 software engineering02 engineering and technologyTransitive setRelational algebraTransitive reductionAlgebraTheoryofComputation_MATHEMATICALLOGICANDFORMALLANGUAGESOperator (computer programming)TheoryofComputation_LOGICSANDMEANINGSOFPROGRAMS020204 information systems0202 electrical engineering electronic engineering information engineeringMathematicsProceedings of the seventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS '88
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