1. The number of levels of factors (same for each factor) is equal to the number of
experiments and for each level there is only one experiment. This is similar to
the Latin hypercube design.
2. The points of experiments are distributed as uniformly as possible in the domain
of variables. There is a physical analogy with the minimum of potential energy of
repulsive forces for a set of points of unit mass, if the magnitude of these
repulsive forces is inversely proportional to the distance squared between the
points: