1. Dynamic Web Service Composition within a Service-Oriented Architecture Ivan J. Jureta, St´ephane Faulkner Info. Manag. Research Unit (IMRU) University of Namur, Belgium iju@info.fundp.ac.be, sfaulkne@fundp.ac.be Youssef Achbany, Marco Saerens Info. Syst. Research Unit (ISYS) Universit´e de Louvain, Belgium {youssef.achbany, marco.saerens}@ucLouvain.bemarco.saerens}@ucLouvain.be 2007 IEEE International Conference on Web Service (ICWS 2007) 69721022

2. Outline Introduction Service Center Architecture Randomized RL Algorithm Experimental Result Conclusion and Future Work

3. Introduction Managing the complexity of systems is considered a key challenge in computing and is addressed through various approaches aimed at increased automation. Service center openness resource distribution adaptability

4. Service Center Architecture Contain one Mediator and all distinct Web Service Mediator negotiates observe compose RRL(Randomized Reinforcement learning) - guide Mediators composition behavior

5. Service Center Architecture Definition 1 - a Web Service (WS) w. Definition 2 - Definition 3 - a Composite Web Service (CWS)

6. Service Center Architecture Definition 4 - a Service Request(SReq) - Definition 5 - Definition 6 - a Service Center(SC) c

7. Service Center Architecture Definition 7 - Service Support Center(SSC) Definition 8 - SCA,

8. Randomized RL Algorithm CWS provision problem

9. Randomized RL Algorithm Definition 9 - the degree of exploration Definition 10 -, To minimizing total expected cost -

10. Randomized RL Algorithm Computing the Optimal TA Policy update the estimated WS criterion

11. Experimental Results

14. Conclusions and Future Work Outperforming standard -greedy and naive Boltzmann. Experimentation of architecture and the extension of service graph specifications