Heuristic algorithm for optimal allocation of vertices in hierarchical digraphs

A heuristic algorithm for drawing visually understandable hierarchical directed graphs is presented. The algorithm finds an allocation of vertices on a circumference so that the number of crossings of arcs is as small as possible. Directed graphs considered are Hasse diagrams that represent partial orders. Especially, the skeleton digraph, that is the final production of the interpretive structural modeling, is taken into account. This research forms a part of the development of an interactive modeling support system that is highly user-friendly computer software to develop lareg-scale system models, using statistical and graph-theoretical approaches cooperatively. [In Japanese.]