Smart Cities, Green Technologies, and Intelligent Transport Systems 4th International Conference, SMARTGREENS 2015, and 1st International Conference VEHITS 2015, Lisbon, Portugal, May 20-22, 2015, Revised Selected Papers - Helfert, Markus 1970-; Krempels, Karl-Heinz 1971-; Klein, Cornel; Donnellan, Brian; Gusikhin, Oleg (Communications in Computer and Information Science, 2015)