Section: New Results

A hidden renewal model for monitoring aquatic systems biosensors

Participants : Romain Azaïs, Raphaël Coudret.

This work aims at modeling signals of oysters' openings over time using a four-state renewal process. Two of them are of particular interest and correspond to instants when the animals are open or closed. An estimator of the cumulative jump rate of this process is provided. It relies on observations of the jumps between the four states. Here these measures are not available but the observed signal takes ranges of real values according to this underlying process. A procedure to estimate a probability density function that summarizes the information of the signal is explained. This leads to estimate the hidden renewal process and then its cumulative jump rate for each oyster. A classification of these functions for a group of oysters discriminate them according to their assumed health status. Such a diagnosis is essential when using these animals as biosensors for water quality assessment. This work is a joint work with Gilles Durrieu from Université de Bretagne Sud and in collaboration with UMR CNRS 5805 EPOC.