  Geometrical properties of two-dimensional mixtures near the jamming
transition point are numerically investigated using harmonic particles under
mechanical training. The configurations generated by the quasi-static
compression and oscillatory shear deformations exhibit anomalous suppression of
the density fluctuations, known as hyperuniformity, below and above the jamming
transition. For the jammed system trained by compression above the transition
point, the hyperuniformity exponent increases. For the system below the
transition point under oscillatory shear, the hyperuniformity exponent also
increases until the shear amplitude reaches the threshold value. The threshold
value matches with the transition point from the point-reversible phase where
the particles experience no collision to the loop-reversible phase where the
particles' displacements are non-affine during a shear-cycle before coming back
to an original position. The results demonstrated in this paper are explained
in terms of neither of universal criticality of the jamming transition nor the
nonequilibrium phase transitions.
