頂点彩色問題の定式化を応用したスラブ山分け問題求解技術開発

抄録

In the steel industry, the role of the slab yard which is the intermediate process between the steelmaking and the rolling is becoming significant. By promoting the logistics from steelmaking to rolling, we can reduce the cost of fuel to reheating and improve the productivity. In the slab yard, slabs are expected to be sorted into stacks as little transport as possible and as high as possible. It is the slab stacking problem. In this paper, we find a slab stacking problem has the similar structure with the vertex coloring problem. There are some kinds of formulations for the vertex coloring problem. We show the fractional programming formulation and the asymmetric representatives formulation for the vertex coloring problem are useful for this problem. Finally we prove the efficiency of those methods compared with the conventional method by the computational experiment with the real operational data.