1
CSE 421
Algorithms
Richard Anderson
Lecture 25
Open Pit Mining
Today’s topics
•
Open Pit Mining Problem
•
Task Selection Problem
•
Reduction to Min Cut problem
S, T is a cut if S, T is a partition of the vertices with
s in S and t in T
The capacity of an S, T cut is the sum of the capacities of
all edges going from S to T
Open Pit Mining
•
Each unit of earth has a profit (possibly
negative)
•
Getting to the ore below the surface
requires removing the dirt above
•
Test drilling gives reasonable estimates of
costs
•
Plan an optimal mining operation
Mine Graph
3
10
4
3
2
3
1
8
2
4
3
1
7
10
1
Determine an optimal mine
10
10
10
10
10
5
1
10
10
10
10
3
3
4
6
10
10
4
3
7
8
1
10
4
3
2
6
4
10
2
4
10
3
4
10
4
4
3
10
10
10
3
3
10
10
10
10
1
10
10
10
10
10
7
Generalization
•
Precedence graph
G=(V,E)
•
Each v in V has a
profit p(v)
•
A set F if
feasible
if
when w in F, and
(v,w) in E, then v in F.
•
Find a feasible set to
maximize the profit
5
10
6
1
2
3
4
4
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
2
Min cut algorithm for profit
maximization
•
This is the end of the preview.
Sign up
to
access the rest of the document.
 Fall '06
 RichardAnderson
 Algorithms, Optimization, Flow network, open pit mining

Click to edit the document details