2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/17094We 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.8 pages, 6 figures, submitted to Europhys. Lett; Corrected typosSoft Condensed MatterStatistical Mechanicstext