“…In spite of the fact that many relational fuzzy clustering algorithms have been developed already (Roubens, 1978;Windham, 1985;Hathaway et al, 1989;Hathaway and Bezdek, 1994;Bezdek et al, 1999;Inoue and Urahama, 1999;Yang and Shih, 2001;Davé and Sen, 2002;Brouwer, 2009), they all involve manually specified parameters such as the number of clusters or threshold of similarity without providing any guidance for choosing them, which is a weakness to develop decision-support or expert systems. Indeed, the determination of the number of clusters in data is a fundamental problem in cluster analysis (see Mirkin (2011a) for a state-of-the-art perspective).…”