Technological innovation for sustainability Second IFIP WG 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems, DoCEIS 2011, Costa de Caparica, Portugal, February 21-23, 2011 : proceedings - IFIP WG 5.5/SOCOLNET Doctoral Conference on Computing, Electrical and Industrial Systems (Springer Berlin Heidelberg, 2011)