  We present our results for the on-shell Delta I = 3/2 kaon decay matrix
elements using domain wall fermions and the DBW2 gauge action at one coarse
lattice spacing corresponding to 1/a = 1.31 GeV in the quenched approximation.
The on-shell matrix elements are evaluated in two different frames: the
center-of-mass frame and non-zero total-momentum frame. We employ the formula
proposed by Lellouch and L\"uscher in the center-of-mass frame, and its
extension for non-zero total momentum frame to extract the infinite volume,
on-shell, center-of-mass frame decay amplitudes. We determine the decay
amplitude at the physical pion mass and momentum from the chiral extrapolation
and an interpolation of the relative momentum using the results calculated in
the two frames. We have obtained Re(A_2) = 1.66(23)(^{+48}_{-03})(^{+53}_{-0})
x 10^{-8} GeV and Im(A_2) = -1.181(26)(^{+141}_{-014})(^{+44}_{-0}) x 10^{-12}
GeV at the physical point, using the data at the relatively large pion mass,
m_pi > 0.35 GeV. The first error is statistic, and the second and third are
systematic. The second error is estimated with several fits of the chiral
extrapolation including (quenched) chiral perturbation formula at next to
leading order using only lighter pion masses. The third one is estimated with
an analysis using the lattice dispersion relation. The result of Re(A_2) is
reasonably consistent with experiment.
