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  • Apr
    15

    Appl Math: Dan Wilson on "Phase-Amplitude-Based Techniques for Control and Analysis of Strongly Perturbed Limit Cycle Oscillators"

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    11:15 AM M416, Technological Institute

    EVENT DETAILS

    Title: Phase-Amplitude-Based Techniques for Control and Analysis of Strongly Perturbed Limit Cycle Oscillators

    Speaker: Dan Wilson, University of Tennessee, Knoxville

    Abstract: While phase-based reduction techniques have a rich history in the analysis and control of oscillatory dynamical systems, the overwhelming majority of theoretical analysis in this field has been performed in the weakly perturbed limit. Comparatively very little is understood about limit cycle oscillators in response to strong and/or long-lasting perturbations, mostly due to the lack of viable reduction strategies that are valid when considering strong perturbations. In this presentation, I will discuss the use of isostable coordinates, which characterize level sets of the slowest decaying eigenmodes of the Koopman operator in conjunction with phase-based techniques to yield analytically tractable reduced order models that are valid in the strongly perturbed regime. Applications involving phase resetting of circadian rhythms following rapid travel across multiple time zones illustrate the utility of these new methods in situations where standard, phase-only techniques fail. I will also discuss related work motivated by experimental and detailed computational studies finding that coupled circadian oscillators with decreased levels of synchronization are able to more rapidly adjust to changes in circadian time. Theoretical analysis reveals the dynamics of mean-field coupled oscillators can be considered in the context of a supercritical Hopf bifurcation, ultimately providing an explanation for the fundamental relationship between synchronization and phase resetting efficiency. In the context of jet-lag recovery strategies, further analysis reveals that transient desynchronization facilitates phase resetting when the relaxation rate of the population limit cycle is sufficiently slow relative to the natural frequency of the population oscillation.

    Zoom: https://northwestern.zoom.us/j/91324444590

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    TIME Tuesday, April 15, 2025 at 11:15 AM - 12:15 PM

    LOCATION M416, Technological Institute    map it

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    CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

    CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  • Mar
    31

    Spring Break Ends

    University Academic Calendar

    All Day

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    TIME Monday, March 31, 2025

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    CONTACT Office of the Registrar    nu-registrar@northwestern.edu EMAIL

    CALENDAR University Academic Calendar

  • Apr
    1

    Spring Classes Begin - Northwestern Monday: Classes scheduled to meet on Mondays meet on this day.

    University Academic Calendar

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    TIME Tuesday, April 1, 2025

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    CONTACT Office of the Registrar    nu-registrar@northwestern.edu EMAIL

    CALENDAR University Academic Calendar

  • Apr
    8

    Appl Math: Brennan Sprinkle on "The Countoscope: Counting Particles to Measure Dynamic Properties of Suspensions In and Out of Equilibrium"

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    11:15 AM M416, Technological Institute

    EVENT DETAILS

    TIME Tuesday, April 8, 2025 at 11:15 AM - 12:15 PM

    LOCATION M416, Technological Institute    map it

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    CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

    CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  • Apr
    22

    Appl Math: Todd Murphey on "Control for Embodied Learning"

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    11:15 AM M416, Technological Institute

    EVENT DETAILS

    TIME Tuesday, April 22, 2025 at 11:15 AM - 12:15 PM

    LOCATION M416, Technological Institute    map it

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    CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

    CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  • May
    6

    Appl Math: Chris Vogl on "Title TBA"

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    11:15 AM M416, Technological Institute

    EVENT DETAILS

    TIME Tuesday, May 6, 2025 at 11:15 AM - 12:15 PM

    LOCATION M416, Technological Institute    map it

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    CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

    CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  • May
    27

    Appl Math: Yiping Lu on "Two Tales, One Resolution: Physics-Informed Test Time Scaling and Precondition"

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    11:15 AM M416, Technological Institute

    EVENT DETAILS

    TIME Tuesday, May 27, 2025 at 11:15 AM - 12:15 PM

    LOCATION M416, Technological Institute    map it

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    CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

    CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  • Jun
    15

    2024-2025 Commencement Ceremony

    University Academic Calendar

    All Day

    EVENT DETAILSmore info

    TIME Sunday, June 15, 2025

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    CONTACT Office of the Registrar    nu-registrar@northwestern.edu EMAIL

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