抄録
In the 1980's the R & D targets of Japanese large chemical firms were (1) electronics materials, (2) advanced structural materials and (3) biotechnology products. The chemical firms made efforts to discover new products by using these categories. Although the firms succeeded in diversifying their businesses, their new products were associated in not technically but semantically one another. This paper explains the reason why this phenomenon occurred by using the concepts of semantic network and social system.
