关键词: Pi演算，进程代数，粒子群优化，服务选择

Abstract: An extended Pi-calculus is proposed to model the Qos-aware service selection using PSO(Particle Swarm Optimization). Firstly, the syntactic components are expanded,which include the beam-channel with dimension and concurrency constraints based on channel, paralleling linkage derived from parallel composition and stochastic and cost choice from summation. Secondly, the semantics of the extended Pi-calculus which import the cost measure function and PSO meta-control primitives are illustrated. Finally, based on this target language, the discrete scheme of PSCTDPSO is used to solve a service selection with a real scenario in multimedia conference with the modeling and simulation. The simulation results show that this method can ensure the good performance and scalability.

Key words: Pi-calculus, Process algebra, PSO(Particle swarm optimization) , Service selection