  To obtain the precise values of the bulk quantities and transport
coefficients in quark-gluon-plasma phase, we propose that a direct calculation
of the renormalized energy-momentum tensor (EMT) on the lattice using the
gradient flow. From one-point function of EMT, authors in Ref.[1] obtained the
interaction measure and thermal entropy. The results are consistent with the
one obtained by the integral method. Based on the success, we try to measure
the two-point function of EMT, which is related to the transport coefficients.
Advantages of our method are (1) a clear signal because of the smearing effects
of the gradient flow and (2) no need to calculate the wave function
renormalization of EMT. In addition, we give a short remark on a comparison of
the numerical cost between the positive- and adjoint-flow methods for fermions,
needed to obtain the EMT in the (2+1) flavor QCD.
