  The two matrix spectral problems of Ablowitz-Kaup-Newell-Segur (AKNS) and
Kaup-Newell (KN) types associated with so(3,R) are generalized. The
corresponding hierarchies of generalized soliton equations are derived by the
standard procedure using the zero curvature formulation. Recursion operators
and bi-Hamiltonian structures are explicitly constructed for the resulting two
generalized soliton hierarchies of AKNS and KN types, which shows their
Liouville integrability.
