  The Yangian characters (or q-characters) are known to be closely related to
the classical W-algebras and to the centers of the affine vertex algebras at
the critical level. We make this relationship more explicit by producing
families of generators of the W-algebras from the characters of the
Kirillov-Reshetikhin modules associated with multiples of the first fundamental
weight in types B and D and of the fundamental modules in type C. We also give
an independent derivation of the character formulas for these representations
in the context of the RTT presentation of the Yangians. In all cases the
generators of the W-algebras correspond to the recently constructed elements of
the Feigin-Frenkel centers via an affine version of the Harish-Chandra
isomorphism.
