  Reorientation of the segregation pattern of a binary granular mixture on a
two-dimensional hor- izontally oscillating tray is numerically realized. The
mixture consists of large-and-heavy particles and small-and-light particles,
the segregation pattern of which shows a transition between a striped pattern
perpendicular to the oscillation and that parallel to the oscillating direction
according to the change of area-fractions of two types of particles. The
transition mechanism is discussed on the basis of a simplified 1-dimensional
dynamics.
