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Events for September 04, 2019

  • Center for Cyber-Physical Systems and Internet of Things and Ming Hsieh Institute Seminar

    Wed, Sep 04, 2019 @ 02:00 PM - 03:00 PM

    Ming Hsieh Department of Electrical and Computer Engineering

    Conferences, Lectures, & Seminars

    Speaker: Gaurav Gupta, Electrical & Computer Engineering, University of Southern California

    Talk Title: Dealing with Unknown Unknowns: Compact Perception from Heterogeneous Data

    Series: Center for Cyber-Physical Systems and Internet of Things

    Abstract: Deciphering patterns from heterogeneous and noisy data to make robust inferences require knowledge of the complete system. Even with big data sizes, the presence of unknown unknowns (contributors) may not be neglected due to complex interactions of the observed system with the unobserved components and the environment (e.g., brain, social networks, gene-regulatory networks, physiological signals). In this talk, we will discuss the incorporation of unknown unknowns in the context of non-stationary non-Markovian processes. A multi-scale approach is used to model the non-Markovian time-dependence of the complex network nodes. The behavior is modeled using fractional differential equations. The benefits of this approach are demonstrated by modeling the real-world biological data of brain electroencephalogram (EEG), neuron spikes, and physiological signals like temperature and heartbeat intervals while considering the prediction of brain state or the prediction of viral infection. We will also describe how a compact model can be efficiently used to tackle some practical problems in brain machine interfaces and viral prediction in a different perspective than the traditional machine learning approaches.

    Biography: Gaurav Gupta is a Ph.D. student working under the supervision of Prof. Paul Bogdan in the Ming Hsieh Department of Electrical and Computer Engineering at University of Southern California. He received his B.Tech degree from Indian Institute of Technology Kanpur in 2013 and M.S. from University of California Irvine in 2016, both in Electrical Engineering. His research interests include modeling of complex networks in the presence of unknown unknowns, discrete optimization, information theory for machine and representation learning, network inference for biological and social networks and the science biological computation.

    Host: Paul Bogdan

    Location: Hughes Aircraft Electrical Engineering Center (EEB) - 132

    Audiences: Everyone Is Invited

    Posted By: Talyia White

  • AME Seminar

    Wed, Sep 04, 2019 @ 03:30 PM - 04:30 PM

    Aerospace and Mechanical Engineering

    Conferences, Lectures, & Seminars

    Speaker: Basile Radisson, USC

    Talk Title: Insights into the Nonlinear Evolution of Flame Fronts through Experiments and Models

    Abstract: Due to the exothermicity of combustion reaction, premixed flames are intrinsically unstable. Consequently, cellular patterns are formed on the flame front resulting in rich and complex dynamics. Combustion involves several hundreds of elementary chemical reactions occurring at a submillimetric interface, rendering a detailed description computationally intractable. Simplified models offer much insight into these complex dynamics. Through asymptotic analysis, the shape of the flame front can be described by a set of poles and their dynamic evolution in the complex plane. Here, we demonstrate for the first time the validity of such model in comparison to experimental flame evolution. A premixed flame propagates in a reactive mixture held between two vertically oriented ceramic glass plates separated by a 5mm gap. By extracting a flame front from this experiment, we demonstrate the feasibility of describing the shape of the front by a set of pole solutions. The flame front dynamics are well described for approximately ten times the characteristic time of the instability. Beyond this time, the comparison is limited by the sensitivity to initial condition. However, by studying statistical properties of the flame front, here statistics of cell sizes, we demonstrate that the pole description is still valid at long time. Moreover, these statistics satisfy a gamma distribution, characteristic of phenomena for which the elementary interaction rule is of additive nature and which results here from the pole to pole attraction. This analytical prediction of the cell-size distribution could be of great interest for the understanding of turbulent flame dynamics.

    Biography: Basile Radisson is a postdoctoral scholar in the Aerospace and Mechanical Engineering department at the University of Southern California since June 2019. Prior to joining USC, Basile received his PhD from IRPHE, AixMarseille Universite, France, working on flame front dynamics under the supervision of C. Almarcha and B. Denet. His research interests lie in instability phenomena driven by geometric nonlinearities. He is currently working on snap instabilities in fast elastic filaments under the supervision of E. Kanso.

    Host: Kanso

    Location: SLH 102

    Audiences: Everyone Is Invited

    Posted By: Tessa Yao