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Currently, a particular focus of human centered technology is in expanding traditional contextual sensing and smart processing capabilities of ubiquitous systems exploiting user's affective and emotional states to develop more natural communication between computing artefacts and users. This paper presents a smart environment of Web services that has been developed to integrate and manage different existing and new emotion sensing applications, which working together provide tracking and recognition of human affective state in real time. In addition, two emotion interpreters based on the proposed 6-FACS and Distance models have been developed. Both models operate with encoded facial deformations described either in terms of Ekman's Action Units or Facial Animation Parameters of MPEG-4 standards. Fuzzy inference system based on reasoning model implemented in a knowledge base has been used for quantitative measurement and recognition of three-level intensity of basic and non-prototypical facial expressions. Designed frameworks integrated to smart environment have been tested in order to evaluate capability of the proposed models to extract and classify facial expressions providing precision of interpretation of basic emotions in range of 65–96% and non-prototypical emotions in range of 55–65%. The conducted tests confirm that such basic as non-prototypical expressions may be composed by other basic emotions establishing in this way the concordance between existing psychological models of emotions and Ekman's model traditionally used by affective computing applications.

AbstractAn approach for a biometrie cryptosystem based on keystroke dynamics and the k-medoids algorithm is proposed. The stages that comprise the approach are training enrollment and user verification. The proposed approach is able to verify the identity of individuals offline avoiding the use of a centralized database. The approach as reported in this paper may be implemented in stand-alone terminals or embedded in password-based systems to increase the security. The performance of the proposed approach is assessed using 20 samples of keystroke dynamics from 20 different users. Simulation results show a false acceptance rate of 2.89% and a false rejection rate of 3.35%. The cryptographic key released by the proposed architecture may be used in several potential applications such as user login, file encryption or even portable authentication to gain access to virtual private networks.