Impact of Noise Correlation on Multimodality

International audience—In this paper, we consider the problem of estimating an unknown random scalar observed by two modalities. We study two scenarios using mutual information and mean square error. In the first scenario, we consider that the noise correlation is known and examine its impact on the information content of two modalities. In the second scenario we quantify the information loss when the considered value of the noise correlation is wrong. It is shown that the noise correlation usually enhances the estimation accuracy and increases information. However, the performance declines if the noise correlation is misdefined, and the two modalities may jointly convey less information than one single modality

Spray, Embracing Multimodality

We present Spray, a localization system that compensates for low accuracy of individual localization measurements by combining measurements from multiple localization modalities

The interplay of intrinsic and extrinsic bounded noises in genetic networks

After being considered as a nuisance to be filtered out, it became recently clear that biochemical noise plays a complex role, often fully functional, for a genetic network. The influence of intrinsic and extrinsic noises on genetic networks has intensively been investigated in last ten years, though contributions on the co-presence of both are sparse. Extrinsic noise is usually modeled as an unbounded white or colored gaussian stochastic process, even though realistic stochastic perturbations are clearly bounded. In this paper we consider Gillespie-like stochastic models of nonlinear networks, i.e. the intrinsic noise, where the model jump rates are affected by colored bounded extrinsic noises synthesized by a suitable biochemical state-dependent Langevin system. These systems are described by a master equation, and a simulation algorithm to analyze them is derived. This new modeling paradigm should enlarge the class of systems amenable at modeling. We investigated the influence of both amplitude and autocorrelation time of a extrinsic Sine-Wiener noise on: $(i)$ the Michaelis-Menten approximation of noisy enzymatic reactions, which we show to be applicable also in co-presence of both intrinsic and extrinsic noise, $(ii)$ a model of enzymatic futile cycle and $(iii)$ a genetic toggle switch. In $(ii)$ and $(iii)$ we show that the presence of a bounded extrinsic noise induces qualitative modifications in the probability densities of the involved chemicals, where new modes emerge, thus suggesting the possibile functional role of bounded noises

Focal Spot, Fall/Winter 2002/2003

https://digitalcommons.wustl.edu/focal_spot_archives/1092/thumbnail.jp

Multiple regimes in operation of the Swiss railway system and potential influences on power load

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Analysis of the noise of a system is often an effective way to obtain information about its internal dynamics. In this paper, an analysis of the variance of the noise on the power load curve of the Swiss railway system guides us toward the detection of a multimodality in the distribution of punctualities. This multimodality is regarded as a strong indicator for a dynamics with multiple, possibly self-organized, regimes. The presence of multiple regimes in the dynamics is of relevance for the design of operational strategies. Based on the information about the operation of the Swiss regular interval time table, we suggest and apply a simple way to identify the part of the load signal that can be regarded as noise, and we demonstrate the use of Hartigan's dip test for the identification of multimodalities in the distribution of random variables