The classification of a set of alternatives into predefined homogenous groups is a problem with major practical interest in many fields. Over the past two decades several non-parametric approaches have been developed to address the classification problem, originating from several scientific...

Markowitz's classical model, as well as other models derived from it (Tobin, Black, …), have raised the problem of the analysis and selection of portfolio securities using statistical instruments that assume a regular and efficient market. This is not usually the case. Although some authors...