Visual modeling of DEVS-based multiformalism systems based on higraphs

Abstract

This paper presents a graphical modeling method and tool for DEVS model and DEVS-based combined discrete/continuous model specification. In DEVSbased modeling, atomic model behavior specification is organized around different phases which define a partition of the state space of the model. The phase transitions depict the qualitative state changes and naturally lend themselves to be represented by a state transition diagram. Our representation of these phase transitions is based on the higraph extension to conventional graph representations. In higraphs, the area of the diagram is used to represent set enclosure and exclusion and the Cartesian product which leads to remarkable reduction in the diagram's complexity. An interactive modeling tool based on the graphicaI representation developed is presented. 1