| | Combinatorial and Integer Optimization (Site not responding. Last check: 2007-10-09) |
 | | The difficulty arises from the fact that unlike linear programming, for example, whose feasible region is a convex set, in combinatorial problems, one must search a lattice of feasible points or, in the mixed-integer case, a set of disjoint halflines or line segments to find an optimal solution. |
 | | The underlying idea of polyhedral combinatorics is to replace the constraint set of an integer programming problem by an alternative convexification of the feasible points and extreme rays of the problem. |
 | | The major components of this algorithm consist of automatic reformulation procedures, heuristics which provide "good" feasible integer solutions, and cutting plane procedures which tighten the linear programming relaxation to the combinatorial problem under consideration -- all of which is embedded into a tree-search framework as in the branch-and-bound approach to integer programming. |
| iris.gmu.edu /~khoffman/papers/newcomb1.html (5076 words) |