[1] Continental Digital Serv France, F-31100 Toulouse, France
[2] Paul Sabatier Univ, IRIT Comp Sci Res Inst Toulouse, Cooperat Multiagent Syst Team, F-31062 Toulouse, France
[3] KTH Royal Inst Technol, Dept Civil & Architectural Engn, S-10044 Stockholm, Sweden