********************************************************************* * Ecole Normale Supe'rieure * * * * Se'minaire * * SEMANTIQUE ET INTERPRETATION ABSTRAITE * * P. Cousot * * * * Vendredi, 14h00--15h30 * * Salle R, etage -1 * * DI ENS 45 rue d'Ulm 75005 Paris * ********************************************************************* NOTER LE CHANGEMENT DE SALLE ********************************************************************* *** Vendredi 12 janvier 2001 **** 14h00 ***************************** Rela^che (IFIP WG 2.3) *** Vendredi 19 janvier 2001 **** 14h00 ***************************** Rela^che (POPL'01) *** Vendredi 26 janvier 2001 **** 14h00 ***************************** Francesco LOGOZZO (LIX) An abstract interpretation based approach to performance modelling Re'sume' : In last times the problem of evaluating concurrent systems performances has been addressed by many authors. Briefly, standard solution consists of augmenting action labels of an existing process algebra with an exponential random variable. An exponential variable is characterized by its parameter, so that actions in process algebra have the form where "a" is the action performed and "r" is the real number characterizing the random variable. Then a stochastic process is assigned to a particular transition system and the proof of its markiovanity is carried on. This standard approach is unsatisfactory for two reason: - System designer is required to specify too much information on the architecture in early stages of designing - Just actions and syncronizations are considered in order to assign costs to transitions: all the other operators of process algebra are forgotten We will show how starting from a standard pi-calculus semantics a new stochastic algebra that avoids the above sketched problems is designed. This semantics turns out to be more concrete than others present in literature (as Priami's Stochastic pi-calculus). Furthemore an abstraction from a transition system to a Markov Chain is presented so that any proof of markovianity is required. Eventually, as a consequence of our construction, a new bisimulation is introduced. ********************************************************************* Pour recevoir l'annonce par courrier electronique: cousot@di.ens.fr WWW: http://www.di.ens.fr/~cousot/annonceseminaire.shtml *********************************************************************