Online temporal reasoning for event and data streams processing

Online fuzzy expert systems can be used to process data and event streams, providing a powerful way to handle their uncertainties and their inaccuracy. Moreover, human experts can decide how to process the streams with rules close to natural language. However, to extract high level information from these streams, they need at least to describe the temporal relations between the data or the events. In this paper, we propose a straightforward way to design temporal operators which relies on the mathematical definition of some base operators and then their combination into more sophisticated operators to assess precedence, periodicity or persistence. We also introduce the concept of expiration of temporal expressions on online fuzzy expert systems, that is to say the capacity to change the values of outputs whereas the inputs have not changed.