결측치를 포함한 데이터의 k-평균 군집분석 방법 비교

Abstract

Cluster analysis is an unsupervised learning method to find heterogeneous clusters that capture similarities among items and separate different items into different clusters. Various cluster analysis techniques have been proposed, and the k-means clustering method, which minimizes the sum of Euclidean distances between cluster centroids and individual entities, is widely recognized as a standard cluster analysis method. When data include missing values, it is challenging to conduct cluster analysis, because it is impossible to calculate distances between centroids of clusters and incomplete items, resulting in excluding classification of these items. Techniques have been suggested to handle missing values in k-means clustering, including conducting cluster analysis after imputation of missing values or cluster analysis based on available information. In this study, we explore methods to perform k-means cluster analysis on data with missing values and evaluate performance of these methods using a simulation. The results of simulation studies indicate that conducting k-means cluster analysis after imputation yields the better performance than the one based on available information. Among the various imputation methods, k-nearest neighbors imputation performed the best.