Events
Past Event
WED@NICO SEMINAR: Raissa D'Souza, University of California, Davis "Complex Networks with Complex Nodes: Emergent Behaviors and Control"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Raissa D'Souza, Professor and Associate Dean for Research, College of Engineering, University of California, Davis
Title:
Complex Networks with Complex Nodes: Emergent Behaviors and Control
Abstract:
Real world networks -- from brain networks to social networks to critical infrastructure networks -- are composed of nodes with nonlinear behaviors coupled together via highly non-trivial network structures. Approaches from statistical physics reveal the fundamental implications that complex network structure has on network function and resilience. In contrast, approaches from dynamical systems and control theory reveal the impact that nonlinear nodal dynamics have on emergent behaviors when connected together in simple networks. This talk presents recent work bridging the fields. We show that the interaction between the nodal dynamics and network structure can give rise to novel emergent synchronization behaviors and extend the analysis of cluster synchronization to hypergraphs, capturing higher-order interactions in networks. With respect to cascading failures, we show that adding in oscillatory nodal dynamics to classic models of self-organized-criticality leads to an emergent timescale and the occurrence of self-amplifying dragon king failures that wipe out the system. Finally, we discuss the frontiers of control of complex networks with non-linear nodes, identifying the key challenges and opportunities for bridging control theory, dynamical systems and statistical physics.
Speaker Bio:
Raissa D'Souza uses the tools of statistical physics and applied mathematics to develop mathematical models capturing the interplay between the structure and function of networks, including dynamical processes unfolding on networks. Her focus is on the abrupt onset of large-scale connectivity in networks, network synchronization behaviors and models of cascading failure. The general principles derived provide insights into the behaviors of real-world networks such as infrastructure networks and social networks, and opportunities to identify small interventions to control the self-organizing, collective behaviors displayed in these systems. She collaborates broadly with faculty within the college and in physics, statistics, political science and the Primate Center.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/92514761999
Passcode: NICO2023
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems and data science. It brings together attendees ranging from graduate students to senior faculty who span all of the schools across Northwestern, from applied math to sociology to biology and every discipline in-between. Please visit: https://bit.ly/WedatNICO for information on future speakers.
Time
Wednesday, October 4, 2023 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
Data Science Nights - MAY 2026 - Speaker: Xudong Tang, Computer Science and NICO
Northwestern Institute on Complex Systems (NICO)
5:30 PM
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M416, Technological Institute
Details
MAY MEETING: Thursday, May 28, 2026 at 5:30pm (US Central)
LOCATION:
ESAM Conference Room, Tech M416
2145 Sheridan Road, Evanston, IL 60208
AGENDA:
5:30pm - Meet and greet with refreshments
6:00pm - Talk with Xudong Tang, PhD Student, Computer Science, NICO, and the Human-AI Collaboration Lab, Northwestern University
TALK TITLE:
Human and Machine Perception of Voice Similarity
ABSTRACT:
Modern voice cloning systems generate synthetic speech that listeners frequently cannot identify as being synthetic. But a voice can sound natural without sounding like the intended person, and what determines whether a clone is heard as a particular person is an open question. Here we report a large-scale preregistered experiment in which we collected 92,239 responses from 175 participants on their perception of pairs of real recordings, voice clones, and continuously morphed voices drawn from 100 contemporary celebrities across 20 speaker groups. We find that voice clones do not reliably preserve perceived speaker identity, reducing same-speaker judgments by 12.7 percentage points even though the clones are produced by a state-of-the-art text-to-speech model, while leaving different-speaker judgments unchanged. Using continuously morphed stimuli, we find that speakers vary substantially in how much variation their perceived identity tolerates, and that this variation is not predicted by speaker demographics. Speaker embeddings account for 58.9\% (95\% CI = [55.7, 61.9]) of variance in identity judgments, which is more than acoustic features, social attributes, and clone status combined. Once all these observed features are accounted for, clone status adds no additional predictive power. These results shows that the perceptual impact of voice cloning is positional rather than categorical: we can model how listeners judge a voice by how close it falls to the perceptual boundary that defines each speaker's recognizable voice, applying the same criterion to real and synthetic speech alike.
DATA SCIENCE NIGHTS are monthly meetings featuring presentations and discussions about data-driven science and complex systems, organized by Northwestern University graduate students and scholars. Students and researchers of all levels are welcome! For more information: http://bit.ly/nico-dsn
FUTURE DATES:
Data Science Nights will return in September!
Time
Thursday, May 28, 2026 at 5:30 PM - 7:00 PM
Location
M416, Technological Institute Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
Spring 2026 Commencement
University Academic Calendar
All Day
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Spring 2026 Commencement
Time
Sunday, June 14, 2026
Contact
Calendar
University Academic Calendar
Juneteenth - University Closed
University Academic Calendar
All Day
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Juneteenth - University Closed
Time
Friday, June 19, 2026
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University Academic Calendar
Independence Day (observed) - University Closed
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All Day
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Independence Day (observed) - University Closed
Time
Friday, July 3, 2026
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University Academic Calendar
Fall 2026 Classes Begin
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All Day
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Fall 2026 Classes Begin
Time
Wednesday, September 23, 2026
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University Academic Calendar