[1] Univ Santiago de Compostela, Dept Stat Math Anal & Optimizat, Santiago De Compostela, Spain
[2] INDRA, Technol & Consulting, La Coruna, Spain
[3] Univ Santiago de Compostela, Dept Stat Math Anal & Optimizat, Modestya Res Grp, Santiago De Compostela, Spain
[4] Fac Math, Campus Vida S-N, Santiago De Compostela 15782, Spain
[5] INAER, Babcock Int Espana, Alicante, Spain