Weakly distance-regular digraphs whose attached association schemes are regular

In this paper, we study commutative weakly distance-regular digraphs whose attached association schemes are regular, and give a characterization of mixed arcs. As an application, we classify such digraphs of diameter 2.Comment: This paper has been withdrawn by the author because the result of this paper has been added in the paper 2003.0805

Thick weakly distance-regular digraphs

A weakly distance-regular digraph is thick if its attached scheme is regular. In this paper, we show that each commutative thick weakly distance-regular digraph has a thick weakly distance-regular subdigraph such that the corresponding quotient digraph falls into six families of thick weakly distance-regular digraphs up to isomorphism