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Convex geometry and semiflows in P/T nets. A comparative study of algorithms for computation of minimal p-semiflows

  • J. M. Colom
  • M. Silva
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 483)

Abstract

P-semiflows are non-negative left anullers of a net's flow matrix. The importance of these vectors lies in their usefulness for analyzing net properties. The concept of minimal p-semiflow is known in the context of Mathematical Programming under the name "extremal direction of a cone". This connection highlights a parallelism between properties found in the domains of P/T nets and Mathematical Programming. The algorithms known in the domain of P/T nets for computing elementary semi-flows are basically a new rediscovery, with technical improvements with respect to type of problems involved, of the basic Fourier-Motzkin method. One of the fundamental problems of these algorithms is their complexity. Various methods and rules for mitigating this problem are examined. As a result, this paper presents two improved algorithms which are more efficient and robust when handling "real-life" Nets.

Keywords

Structural analysis of P/T nets Minimal semiflows Convex Geometry Extremal direction of a cone Algorithms to compute all minimal semiflows Tests of minimality 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • J. M. Colom
    • 1
  • M. Silva
    • 1
  1. 1.Dpto. Ingeniería Eléctrica e InformáticaUniversidad de ZaragozaZARAGOZASpain

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