1. A method for generating a final signature for an application, comprising: deriving an initial application signature using a model training data set; testing said initial application signature with a single validation data set; obtaining at least one cost minimizing parameter; creating a plurality of trained application signatures using both said at least one cost minimizing parameter and a plurality of preclassified training data sets; testing each of said plurality of trained application signatures using a plurality of preclassified validation data sets; and determining said final signature from said plurality of trained application signatures.