[IEEE 2015 IEEE International Conference on Computer and Information Technology; Ubiquitous Computing and Communications; Dependable, Autonomic and Secure Computing; Pervasive Intelligence and Computing (CIT/IUCC/DASC/PICOM) - LIVERPOOL, United Kingdom (2015.10.26-2015.10.28)] 2015 IEEE International Conference on Computer and Information Technology; Ubiquitous Computing and Communications; Dependable, Autonomic and Secure Computing; Pervasive Intelligence and Computing - Don't Speak to Strangers: The Suspicious Strategy Can Help to Improve Cooperation in Spatial Donation Game