  A schemoid is a generalization of association schemes from the point of view
of small categories. In this article, we discuss schemoid structures for two
kinds of small categories; the canonical small category defined by a poset, and
another small category which arises a poset. We also discuss the schemoid
algebra, that is an analogue of the Bose--Mesner algebra for an association
scheme, for them.

Combinatorics;Category Theory