Chapter 4 DEVS Formalism Basic DEVS Formalism Examples Coupled DEVS Specification Closure Under Coupling Hierarchical Models

Basic DEVS

Basic DEVS: Example Scuba Model Dive Plan Emergency Phone Call Response =dint (“five”) for phase != “five” ,“surface1”, “surface2” dint (“five”,s ) otherwise //except when already on “five

Use Continue(e) to retain next event time of original pulse Basic DEVS: Example FireOnce Neuron and Modifications input state output fire elapsed time pulse t sigma phase refract receptive refract input fire fireDelay >0 size= 1 output size) Use Continue(e) to retain next event time of original pulse

Basic DEVS: Example FireOnce Neuron and Modifications (Continued) input state output fire elapsed time pulse t sigma phase refract input fire t phase state refract sigma elapsed time pulse size = 3 output

Coupled Model Specification DN = < X , Y, D, {Mi }, {Ii }, {Zi,j } > X : a set of input events. Y : a set of output events. D : an index set (names) for the components of the coupled model. For each i Î D , Mi is a component DEVS model. For each i Î D È self , Ii is the set of influencees of i . For each j Î D È self , Zi,j : Yi → Xj is the output translation mapping

Closure Under Coupling DN < X , Y, D, {Mi }, {Ii }, {Zi,j }> DEVS < X, S, Y, dint, dext, dcon, ta, l > DEVS < X, S, Y, dint, dext, dcon, ta, l > Every DEVS coupled model has a DEVS Basic equivalent