  When looking into recent research trends in the field of academic landscape,
citation network analysis is common and automated clustering of many academic
papers has been achieved by making good use of various techniques. However,
specifying the features of each area identified by automated clustering or
dynamically extracted key papers in each research area has not yet been
achieved. In this study, therefore, we propose a method for dynamically
specifying the key papers in each area identified by clustering. We will
investigate variance values of the publication year of the cited literature and
calculate each cited paper's importance by applying the variance values to the
PageRank algorithm.
