Abstract
Optimal path design is a problem that is considered to have wide range of applications. We deal with a path design problem of a pattern that consists of a number of small pattern elements; a pattern consisting of characters or symbols is a typical example. In such a case, we can naturally introduce a kind of hierarchical structure to the problem. In this study, we conduct a generalization of the optimal path design approach that takes advantages of abstraction of smaller pattern elements in lower hierarchy. In addition to characters that are the basic elements of patterns, words as well as combinations of words are abstracted so that they can be applied to an optimal path design of larger pattern. Database of such abstructed pattern elements is also introduced. Some example path designs are conducted; the applicability and the performance of the proposed approach are discussed.
