Affiliation: | 1. Department of Econometrics and Computer Sciences , Warsaw Agricultural University , ul. Nowoursynowska 166, 02-766, Warsaw, Poland;2. Institute of Mathematics , Technological University of Warsaw , pl. Jednosci Robotniczej 1, 00-661, Warsaw, Poland;3. Institute of Fundamental Technological Research , Polish Academy of Sciences , ul. Swietokrzyska 21, 00-049, Warsaw, Poland |