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  • Oct
    15

    Appl Math: Trevor GrandPre on "Model-free Inference from Time-series Data"

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    11:15 AM M416, Technological Institute

    EVENT DETAILS

    Title: Model-free Inference from Time-series Data

    Speaker: Trevor GrandPre, Princeton University

    Abstract: Drawing inferences from experimental data often involves imposing models, which can lead to inaccurate conclusions. Theory sometimes points to quantities that are significant independent of the underlying mechanisms, but making accurate model-free estimates of these quantities can be hard because finite data generates systematic errors. I present two cases where we develop new methods to address and correct these errors: (1) extracting long-term population growth from single-cell lineage data and (2) estimating the evidence for the arrow of time in patterns of neural activity. For population growth, key observables are the number of divisions and generation times along a lineage for a fixed time. Simple growth rate estimators suffer from finite-time bias at short times. This bias scales inversely with time and can be corrected. At longer times, rare events introduce a linearization bias, causing an abrupt phase transition explained by a simple model of disordered systems. Our approach yields accurate estimates provided the lineage counts and lengths stay below the critical point, allowing inference of how mutations and physiological variations impact fitness. In the case of neural activity, the relevant observables are the moments of activity and the waiting times between these moments. Estimating the irreversibility—quantified by the Kullback-Leibler divergence between the distribution of forward and backward trajectories—faces similar biases. Finding the systematic dependence of these biases on sample size allows for accurate estimates, including detecting systems that obey detailed balance, and opens a path to exploring how the brain represents the arrow of time. Generally, this new understanding of how model-free estimators rely on a complex order of limits of the amount of data and the length of each sample may allow quantitative understanding of other relevant processes such as gene regulation, cell-cycle dynamics, and signal transduction.

    Zoom: https://northwestern.zoom.us/j/92938364014

    Special Note: This colloquium is co-sponsored by the Chemical and Biological Engineering department in McCormick

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    TIME Tuesday, October 15, 2024 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
    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
    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

    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)

  • 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 "Improving Global Atmosphere Simulation in Earth System Models with Multiphysics Time Integration Methods"

    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
    12

    Appl Math: Adrienne Fairhall on "In Search of Internal Models" - Reiss Lecture

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    4:00 PM Hive Room 2350, Ford Motor Company Engineering Design Center

    EVENT DETAILS

    TIME Monday, May 12, 2025 at 4:00 PM - 5:00 PM

    LOCATION Hive Room 2350, Ford Motor Company Engineering Design Center    map it

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    CONTACT Ted Shaeffer    ted.shaeffer@northwestern.edu EMAIL

    CALENDAR McCormick-Engineering Sciences and Applied Mathematics (ESAM)

  • May
    13

    Appl Math: Adrienne Fairhall on "Decoding Neurons to Behavior in a Model Organism" - Reiss Lecture

    McCormick-Engineering Sciences and Applied Mathematics (ESAM)

    4:00 PM Hive Room 2350, Ford Motor Company Engineering Design Center

    EVENT DETAILS

    TIME Tuesday, May 13, 2025 at 4:00 PM - 5:00 PM

    LOCATION Hive Room 2350, Ford Motor Company Engineering Design Center    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

    CALENDAR University Academic Calendar

  • Jun
    16

    Northwestern Engineering PhD Hooding and Master's Degree Recognition Ceremony

    McCormick School of Engineering and Applied Science

    9:00 AM 2705 Ashland Ave

    EVENT DETAILS

    TIME Monday, June 16, 2025 at 9:00 AM - 11:00 AM

    LOCATION 2705 Ashland Ave   

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    CONTACT Northwestern Engineering Events    northwestern-engineering-events@northwestern.edu EMAIL

    CALENDAR McCormick School of Engineering and Applied Science