Abstract: The problem of composite Web services selection with multiple composite paths was transformed into a constraint optimal path selection problem. A new optimization algorithm C-MMAS was proposed by integrating Max-Min Ant System into Culture algorithm framework, and was applied to solve the optimal path selection problem. This compuling model consists of a MMAS-based population space, excellent solution-based belief space and communication protocols between the two spaces. After completing MMAS-based evolution, population space carrys out variation-based evolution, and contributes excellent solutions as knowledge to belief space after evolutions. Belief space updates knowledge according to certain optimization principle. When the knowledge in belief has been accumulated and precipitated some generations, it is used to guide the MMAS-based evolution. Due to implementing two evolutionary mechanisms on population and knowledge,making the best use of population's evolutionary mechanism and guidance effect of knowledge, this computing model has improved population's diversity and convergence speed largely, realized the purpose of avoiding precocity and reducing computing expense. Theoretical analysis and experimental results indicate the feasibility and efficiency of this algorithm.

Key words: Composite services selection, QoS constraint, Max-min ant system, Culture algorithm