  We propose new polymer models for Monte Carlo simulation and apply them to a
polymer chain confined in a relatively thin box which has both curved and flat
sides, and show that either an ideal or an excluded-volume chain spends more
time in the curved region than in the flat region. The ratio of the probability
of finding a chain in the curved region and in flat region increases
exponentially with increasing chain length. The results for ideal chains are
quantitatively consistent with a previously published theory. We find that the
same effect appears with excluded-volume chains and a similar scaling relation
can be applied to them up to a certain length of the polymer.
