标题： 排列理论在展开模型中的应用 显示英文标题

标题： Application of arrangement theory to unfolding models

摘要： 排列理论在许多领域中使用的展开模型研究中起着重要作用。 本文描述了如何有效地运用排列理论来解决计数问题，（i）展开模型中可接受排名的数量，以及（ii）展开模型生成的排名模式的数量。 本文主要是说明性的，但也包含了一些新的结果，例如单维情况下排名模式数量的简单上下界。 显示英文摘要

摘要： Arrangement theory plays an essential role in the study of the unfolding model used in many fields. This paper describes how arrangement theory can be usefully employed in solving the problems of counting (i) the number of admissible rankings in an unfolding model and (ii) the number of ranking patterns generated by unfolding models. The paper is mostly expository but also contains some new results such as simple upper and lower bounds for the number of ranking patterns in the unidimensional case.