Special Issue on Advanced Cognitive Systems Based on Nonlinear Analysis

Cognitive systems are being addressed to different computational tasks related to the analysis, processing, interpretation and evaluation of information. Since a relatively short time, the strategies implemented with classic linear models are being reviewed in order to evaluate their potential in the study of nonlinear modeling problems. Speech signal is a clear example of a situation where this is possible. Many aspects of the signal analysis are not well addressed by the conventional models currently used in the field of signal processing. The purpose of the special issue is to present and discuss novel ideas, works and results related to alternative techniques for nonlinear processing, which come from mainstream approaches. Nowadays, the studies based on complex systems have opened new doors in the research field, allowing the improvement of the quality and the results of diverse applications. Nonlinear analysis has made this task easier in areas like audio analysis, voice evaluation, quality of voice, blind source separation, expression detection and voice identification. We summarize the papers as follows, in seven main topics.