1. North Slope Decision Support System: Ice Road Planning Algorithms 3 rd Stakeholder Workshop April 27-28, 2011

2. Ice Road Routing: A Complex Problem Often multiple exploration sites Sometimes multiple possible starting points Avoidance of undesirable/difficult features Water availability Regulatory issues Path re-use in future seasons Multiple objectives Cost Time Risk/Reliability

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4. Ant Colony Systems Based on natural behavior of ants in route finding between nest and food… Pheromones! Algorithm Development

5. Ant Colony Systems Based on natural behavior of ants in route finding between nest and food… Pheromones! Algorithm Development

6. Ant Colony Systems Based on natural behavior of ants in route finding between nest and food… Pheromones! Algorithm Development

7. Ant Colony Systems Based on natural behavior of ants in route finding between nest and food… Pheromones! Algorithm Development

8. Issues to Solve Ants get lost in complex and open topologies Most traditional ACS applications are single objective Our real-world ants have to build their own roads and need water

9. Graph Pruning Keep ants from getting lost by reducing topology to non-redundant paths

10. Graph Pruning Keep ants from getting lost by reducing topology to non-redundant paths

11. Traditional ACS includes link choice heurisitics Exploration versus Exploitation Probabilistic Choice weighted by pheromones and a priori suitability scores Multi-Objective Path-Finding Pher 1 Suit 1 Pher 2 Suit 2 Pher 3 Suit 3

12. Multi-objective ACS includes multiple suitability scores, preference functions, and non- dominated sorting to find pareto-fronts Multi-Objective Path-Finding Pher 1 SuitA 1 SuitB 1 SuitC 1 Pher 2 SuitA 2 SuitB 2 SuitC 2 Pher 3 SuitA 3 SuitB 3 SuitC 3 Obj A Obj B

13. 22 11 33 As the ants move along the path, they search for the nearest available permitted lake to withdraw water from. Water Accounting 4

14. On large open grids, sometimes the paths will have unnecessary bends or curves. Path Straightening

15. The ants can determine the best starting point given a stretch of road. Multiple Start Points

16. Steiner Problem – Minimum Spanning Tree Multiple End Points Waypoint

17. Steiner Problem – Minimum Spanning Tree Multiple End Points

18. When there are more than 3 endpoints then pheromone sharing is used. Multiple End Points

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21. START END RouteTravel Time (hrs) Construction Cost ($) New Permits Needed Orange0.251,400,0002 Green0.41,000,0001 Blue0.451,200,0000

22. The resolution of the roads are limited by the 100m x 100m DEM data used. Water accounting for road construction is dependent upon available lake data. Some data may not be available. Limitations

23. Demonstration

24. 1. Review “Permitting Matrix” 2. Let’s sketch out planning process and identify tasks that NSDSS can help improve How does NSDSS fit into the planning process?

25. “Permitting Matrix”

26. Planning Process