  The scheme of using the Chern-Simons action to regularize the gravitational
Hamiltonian constraint is extended to including the Lorentzian term in the
$k=0$ cosmological model. The Euclidean term and the Lorenzian term are thus
regularized separately mimicking the treatment of full loop quantum gravity.
The new quantum dynamics for the spatially flat Friedmann-Robertson-Walker
model with a massless scalar field as an emergent time is studied. By
semiclassical analysis, the effective Hamiltonian constraint is obtained, which
indicates that the new quantum dynamics has the correct classical limit. The
classical big-bang singularity is again replaced by a quantum bounce. Similar
to the case of quantizing only the Euclidean term, the backward evolution of
the cosmological model determined by the new effective Hamiltonian will be
bounced to an asymptotic de Sitter universe coupled to a massless scalar field,
while the problem of negative energy density of matter in the former case is
resolved.
