Our guest professor Bassam Bamieh will give a seminar tomorrow:
Tuesday October 15, 13.15-14.15, Seminar Room Automatic Control KC 3N27
Speaker: Bassam Bamieh Professor Mechanical Engineering, University of California at Santa Barbara https://sites.engineering.ucsb.edu/~bamieh/
Title: Multiplicative Noise, Structured Stochastic Uncertainty, and Fragility in the Mammalian Cochlea
Abstract: Linear systems with multiplicative noise can exhibit sometimes surprising behaviors that are not possible if only additive noise is assumed. This will be demonstrated with very simple low-dimensional examples, as well as examples from large-scale networks where multiplicative noise models stochastically varying network structures. A general framework of structured stochastic uncertainty is developed to obtain necessary and sufficient conditions for mean-square stability from a purely input/output point of view. This framework is applied to study mechanical stability of the dynamics of the mammalian cochlea, which models the “mechanical spectrum analyzer” features of the cochlea, together with an adaptive gain mechanism which is responsible for the large dynamic range of human hearing. This adaptive gain mechanism appears to also be responsible for phenomena such as otoacoustic emissions and possibly Tinnitus, which appear to have mechanical instability origins. We study the structured stochastic uncertainty model of cochlear mechanics, and show the rather small stability margins which are apparently due to the adaptive gain mechanism.