岩崎　敦・◎上田　俊・横尾　真（九大）

When forming the grand coalition is not possible/optimal, agents need to create a coalition structure. The idea of the core can be extended to such a case. We propose an efficient algorithm called CoreD for checking core-non-emptiness for coalition structures. We experimentally show that when the core is empty, CoreD is by far superior to CoreP . Furthermore, we propose a new solution concept called the weak e-core+.