1. The Coordination of Parallel Search with Common Components Stephen Chen and Gregory PittYork University

2. Heuristic Search • Search Operators • Control Strategies IEA-AIE 2005

3. An Obvious Failing • Point search operators do not have historical information! IEA-AIE 2005

4. Search Operator Strategies • What can be improved? • What is worth keeping? IEA-AIE 2005

5. Random Local Minima IEA-AIE 2005

6. Simulated Annealing IEA-AIE 2005

7. Summary • Random search space, random search strategy • All the intelligence of simulated annealing is in the control strategy IEA-AIE 2005

8. Distribution of Local Minima (Boese) Length Average distance from other local minima IEA-AIE 2005

9. “Big-Valley” – Globally Convex IEA-AIE 2005

10. “Directed” Simulated Annealing IEA-AIE 2005

11. Coordination with Common Components IEA-AIE 2005

12. Restricted Mutations • Parent 1 1 1 1 0 0 1 0 1 1 1 • Parent 2 1 0 1 1 0 1 1 0 1 1 • Common 1 1 0 1 1 1 • Uncommon 1 1 0 0 1 • Uncommon 2 0 1 1 0 IEA-AIE 2005

13. TSP Results IEA-AIE 2005

14. Summary • Globally convex search space, “respectful” search operator • Add some intelligence to the search operator IEA-AIE 2005

15. Conclusion • The preservation of common components can improve the performance of parallel search procedures in globally convex search spaces IEA-AIE 2005