Smart Phone User Behaviour Characterization Based on Autoencoders and Self Organizing Maps

Building applications that are cognizant of temporal and spatial changes in human behaviour under a one-class learning restriction represents a requirement for many user centric systems. We are particularly motivated to demonstrate the utility of algorithms for the self identification of smart phones. A framework is designed to quantify: (i) the dissimilarity in behaviours among any two users, (ii) the exclusivity of each user's behaviour (inclass) from the world (outclass). A central element of the proposed framework is to first identify a discriminating representation for each user. To this end, an autoencoder is employed in which the goal is to identify an encoding that rebuilds the original data with maximum accuracy/ least loss. The hypothesis of this work is that such an autoencoding step provides an effective mechanism for discovering good data representations prior to the application of a data description technique, such as clustering. Both the autoencoder and the clustering steps are performed relative to a single user. We construct a user specific behavioural model using the most frequently used applications, cell towers and websites. We demonstrate that relative to the most up-to-date publicly available smart phone data set, the resulting behavioural models are capable of uniquely identifying each user under a one-class learning constraint.