Problem Analysis

  Physical systems are by nature continuous and operate on a hierarchy of temporal and spatial scales [11,14]. At a given level of interest, more detailed behavior can either be abstracted away (a parameter abstraction) or its effect can be collapsed to occur at a point in time (a time scale abstraction) [10]. In either case, configuration changes in the system topology may occur that cause algebraic constraints between state variables to become active and cause discontinuous changes in their values.