Events
Past Event
WED@NICO SEMINAR: Lightning Talks with Northwestern Fellows and Scholars!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
NICO is hosting a lightning talk seminar each term as a part of our Wednesdays@NICO seminar series. Northwestern graduate students and postdoctoral fellows are invited to participate. To sign up for future lightning talks, please visit: https://bit.ly/2lRqSXK
FALL 2019 SPEAKERS
Diego Gómez-Zará - Ph.D. Candidate, Technology and Social Behavior
Title: A Network Approach to the Formation of Self-assembled Teams
Abstract: Which individuals in a network make the most appealing teammates? Which invitations are most likely to be accepted? And which are most likely to be rejected? This study explores the factors that are most likely to explain the selection, acceptance, and rejection of invitations in self-assembling teams. We conducted a field study with 780 participants using an online platform that enables people to form teams. Participants completed an initial survey assessing traits, relationships, and skills. Next, they searched for and invited others to join a team. Recipients could then accept, reject, or ignore invitations. Using Exponential Random Graph Models (ERGMs), we studied how traits and social networks influence teammate choices. Our results demonstrated that (a) agreeable leaders with high psychological collectivism send invitations most frequently, (b) previous collaborators, leaders, competent workers, females, and younger individuals receive the most invitations, and (c) rejections are concentrated in the hands of a few.
Alex Mercanti - Ph.D Candidate, Engineering Sciences & Applied Mathematics
Title: Protecting your privacy in machine learning using randomness.
Abstract: Machine learning models are commonly trained over datasets that contain personal information about people and their daily routine, health, online activity, and social behavior. Although these models play a crucial role in modern software applications, the extent to which trained machine learning models leak private and sensitive features of their respective training data remains poorly understood. In this talk, I will discuss the privacy risks associated with publicly releasing trained machine learning models and will demonstrate that the addition of random noise to training algorithms guarantees privacy for each individual in the training dataset at minimal cost to the accuracy of the model.
Kyosuke Tanaka - Ph.D Candidate, Media, Technology, and Society
Title: How dispositional and positional factors affect an individual’s ability to efficiently route messages in a network
Abstract: Milgram’s small-world experiment provided evidence for six degrees of separation, on average a chain of five contacts separated any two random people in the world. However, this was only true for those messages that reached the final destination. While, in theory, the small-world phenomenon is structurally common in social networks, empirical evidence shows that human navigation of small-world social networks is remarkably challenging. Messages often reach the intended destination via a longer path than expected, get enmeshed in loops, and/or often never reach it. This leads to painful consequences for organizations that require information routing to share (or retrieve) knowledge among their members. Extreme examples of these failures contributed to the loss of the space shuttles Challenger and Columbia. Here, I present a study of an understudied type of error—network routing—and introduce network acuity to conceptualize and operationalize an individual’s ability to efficiently route messages. Using, 6-DoS (Six Degrees of Separation), a network routing task based on Milgram’s small-world experiment with 435 individuals organized into 25 networks, I explored two types of factors that impact an individual’s network acuity: positional factors (where you are in the network) and dispositional factors (who you are). Results show that (a) those in the core or brokerage position had high network acuity than did peripheral or non-bridge members, (b) neuroticism was positively associated with acuity, (c) conscientiousness was negatively associated with acuity. Further, individuals’ network positions impacted network acuity more than dispositional characteristics. The results of this experimental study illustrate not only the usefulness of the concept of network acuity to characterize network routing errors but also advance our understanding of factors that explain variance in individuals' network acuity.
Alexandria Volkening - NSF-Simons Fellow, NSF-Simons Center for Quantitative Biology
Title: Forecasting U.S. elections with compartmental models of infection
Abstract: U.S. election forecasting involves polling likely voters, making assumptions about voter turnout, and accounting for various features such as state demographics and voting history. While political elections in the United States are decided at the state level, errors in forecasting are correlated between states. With the goal of shedding light on the forecasting process and exploring how states influence each other, we develop a framework for forecasting elections in the U.S. from the perspective of dynamical systems. Through an interdisciplinary approach that borrows ideas from epidemiology, we show how to combine a compartmental model with public polling data from HuffPost and RealClearPolitics to forecast gubernatorial, senatorial, and presidential elections at the state level. Our results for the 2012 and 2016 U.S. races are largely in agreement with those of popular sources, and we use our model to explore how subjective choices about uncertainty impact results. We conclude by comparing our forecasts for the 2018 midterms with those of popular analysts, and we discuss future directions related to the 2020 elections. This is joint work with Daniel Linder (Augusta Univ.), Mason Porter (UCLA), and Grzegorz Rempala (Ohio State Univ.).
Live Stream:
Time
Wednesday, December 4, 2019 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Simbarashe Nkomo, Emory University "Exploring the Emergence of Complex Dynamics in Networks of Belousov-Zhabotinsky Oscillators"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Simbarashe Nkomo, Assistant Professor of Chemistry, Oxford College of Emory University
Title:
Exploring the Emergence of Complex Dynamics in Network of Belousov-Zhabotinsky (BZ) Oscillators
Abstract:
The study of complex systems permeates diverse scientific domains and engineering applications. Through the lens of a nonlinear chemical oscillator, the Belousov-Zhabotinsky (BZ) reaction, we explore the occurrence of complex behaviors in small and large oscillator networks. Using both experiments and theoretical models, we demonstrate the role of coupling strength, coupling mode, initial conditions, and system heterogeneities in the emergence of complex dynamics such as mixed periods, period cycling, and chimera states. We use phase response curves to provide mechanistic insight into how the oscillators’ phases during interactions contribute to the onset of complex dynamics. Our results show that even slight perturbations with correct timing of phases can cause the system to transit from periodic oscillations to more complex behaviors. These studies offer potential strategies for controlling complex dynamics in other real-world applications such as neuronal networks.
Speaker Bio:
Simbarashe (Simba) Nkomo is Assistant Professor of Chemistry at Emory University (Oxford College). His research interests are in chemical nonlinear dynamics, specifically on complex synchronization dynamics in experimental and theoretical BZ models, and chemical predictive toxicity models. Simba has research published in Nature Physics, Physical Review Letters, and Chaos: An Interdisciplinary Journal of Nonlinear Science.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/97359095225
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network 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, April 24, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
NICO AI Seminar: Ziv Epstein, Stanford University "Re-Inventing the Attention Machine"
Northwestern Institute on Complex Systems (NICO)
1:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Ziv Epstein, Postdoctoral Fellow, Stanford Institute for Human-Centered AI, Stanford University
Title:
Re-Inventing the Attention Machine
Abstract:
Modern AI systems - such as LLMs and feed algorithms on social media - are algorithmic amplifiers that uplift certain voices and perspectives. But whose perspectives? In this talk, I will argue that human attention is the key bridge to understanding how we shape these AI amplifiers and how they shape us. In particular, I will argue that AI systems are training on a particular ground truth that is mediated by human attention and as a result is hill-climbing on attentional noise. To what extent is training data transformed by attention? Can we measure it? And can we shift attention to make more deliberate training data? I will discuss ways to measure attentional drift in AI systems, as well as prosocial tools to align behavior and values, and ongoing attempts to embed values into these AI amplifiers explicitly. These projects point to a new way of designing sociotechnical systems for prosocial outcomes, by moving away from attention economies and towards attention ecologies.
Speaker Bio:
Ziv Epstein is a Postdoctoral Fellow at the Stanford Institute for Human-Centered AI. In his research, he focuses on translating insights from design and the social sciences into the development of sociotechnical systems such as generative AI and social media platforms. Ziv has published papers in venues such as the general interest journals Nature, Science and PNAS , as well as top-tier computer science proceedings such as CHI and CSCW. His work has also received widespread media attention in outlets like the New York Times, Scientific American, and NPR.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/98518429787
Passcode: NICO2024
Calendar:
Add to Outlook | Google Calendar
About this Seminar:
NICO welcomes everyone to join us at this AI focused Thursday afternoon seminar. Please note, since this is at 1pm, we will provide light refreshments only.
Time
Thursday, April 25, 2024 at 1:00 PM - 2:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Chris Bail, Duke University "Bridging Divides with Generative AI"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Chris Bail, Professor of Sociology, Political Science, and Public Policy, Duke University
Title:
Bridging Divides with Generative AI
Abstract:
Political discourse is the soul of democracy, but misunderstanding and conflict can fester in divisive conversations. The widespread shift to online discourse exacerbates many of these problems and corrodes the capacity of diverse societies to cooperate in solving social problems. Scholars and civil society groups promote interventions that make conversations less divisive or more productive, but scaling these efforts to online discourse is challenging. This talk will describe a large-scale experiment that demonstrates how online conversations about divisive topics can be improved with AI tools. Specifically, my colleagues and employ a large language model to make real-time, evidence-based recommendations intended to improve participants’ perception of feeling understood. These interventions improve reported conversation quality, promote democratic reciprocity, and improve the tone, without systematically changing the content of the conversation or moving people’s policy attitudes. These findings replicate during a half year experiment on a large social media platform.
Speaker Bio:
Chris Bail is Professor of Sociology, Political Science, and Public Policy at Duke University, where he founded the Polarization Lab. He studies how artificial intelligence shapes human behavior in a range of different settings—and social media platforms in particular. Chris is passionate about building the field of computational social science. He is the Editor of the Oxford University Press Series in Computational Social Science and the Co-Founder of the Summer Institutes in Computational Social Science. Chris received his PhD from Harvard University in 2011.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/97722631639
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network 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, May 1, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Daniel Harris, Brown University "At the interface: physical analogy with interfacial fluid mechanics"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Daniel Harris, Assistant Professor of Engineering, Brown University
Title:
At the Interface: Physical Analogy with Interfacial Fluid Mechanics
Abstract:
Maxwell describes physical analogy as a "partial similarity between the laws of one science and those of another which makes each of them illustrate the other." Hydrodynamics has long since been a source of physical analogy, sharing similar equations with other seemingly disparate fields of physics. The focus of this talk will be on physical analogies with interfacial fluid systems, where accessible tabletop experiments can be used to investigate and communicate physical phenomena at vastly different scales. Following a brief review of some historical examples of analogy in interfacial fluid mechanics, I will describe two recent tabletop experiments developed in our lab that share similarities with certain microscopic colloidal systems. While physical analogy can be fruitfully used to advance science across disciplines, it can also be leveraged to enhance scientific communication and pedagogy.
Speaker Bio:
Daniel M. Harris is an Assistant Professor of Engineering at Brown University in the Fluids and Thermal Sciences group. Before joining Brown, Dan was a Postdoctoral Research Associate and Lecturer at the University of North Carolina at Chapel Hill in the Department of Mathematics. Dan received his B.S. in Mechanical Engineering from Cornell University in 2010 and his Ph.D. in Applied Mathematics from MIT in 2015.
Dan’s primary research interests are in interfacial phenomena, microfluidics, and transport phenomena. His research involves an integrated experimental and theoretical approach. Dan has also received numerous awards for his scientific visualizations, including being selected as the winner of the 2016 NSF/Popular Science Visualization Challenge in Photography, as well as numerous prizes from the American Physical Society’s Gallery of Fluid Motion and Gallery of Soft Matter.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/93585934682
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network 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, May 8, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Eleni Katifori, University of Pennsylvania "TBA"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Eleni Katifori, Associate Professor, Department of Physics & Astronomy, University of Pennsylvania
Title:
TBA
Abstract:
TBA
Speaker Bio:
Eleni Katifori is an Associate Professor in the Department of Physics & Astronomy, University of Pennsylvania. Prof Katifori’s research group are interested in understanding the physics behind the morphological and functional attributes of living organisms. They primarily focus on questions inspired by and related to biological transport networks and the elasticity and geometry of thin sheets. Professor Katifori received her Ph.D from Harvard University in 2008 and a B.S. from the University of Athens, Greece in 2002.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/92857810876
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network 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, May 15, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Serguei Saavedra, MIT "How Do Ecological Systems Become (re)Assembled?"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Serguei Saavedra, Associate Professor, Department of Civil and Environmental Engineering, MIT
Title:
How Do Ecological Systems Become (re)Assembled?
Abstract:
One of the most iconic thought experiments in biology is what would happen if we could rewind the tape of life on Earth and play it again. Would the tape have a different story in every replay? Or is there a general order of events? The relevance of this thought experiment is not just philosophical or counterfactual, because (re)assembly processes undergone by ecological systems, from microbes to mega-fauna, are continuously replicating the experiment. By integrating theoretical and empirical work, in this talk I will provide a guideline to increase our understanding about the (re)assembly possibilities of ecological systems. Explaining and predicting the (re)assembly of ecological systems underpins our ability to develop successful interventions in bio-restoration, bio-technologies, and bio-medicine.
Speaker Bio:
Serguei Saavedra is an Associate Professor at MIT in the Department of Civil and Environmental Engineering. He is also an external faculty at Santa Fe Institute. Serguei is a theoretical ecologist focused on understanding the feasibility of observing the emergence, transformations, and regeneration of ecological systems under environmental changes. Before joining MIT in 2016, Serguei studied systems engineering in Mexico; specialized in mathematical modeling at Genoa University; completed his PhD in engineering science at Oxford University; and did his postdoctoral work at the NICO (under the mentorship of Brian Uzzi), Doñana Biological Station, and in the department of environmental systems at ETH.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/91082510906
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network 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, May 22, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Joseph Paulsen, Syracuse University "TBA"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Joseph Paulsen, Associate Professor, Department of Physics, Syracuse University
Title:
TBA
Abstract:
TBA
Speaker Bio:
Joseph Paulsen earned a bachelor's degrees in Mathematics and Physics from St. Olaf College in Northfield, MN, and he completed his PhD in Physics at the University of Chicago with Sidney Nagel. He won a National Science Foundation CAREER Award for his work that studies connections between geometry and mechanics in thin materials. Outside of science, one of his passions is trying to squirrel away as much time as possible to ski with his 7-year-old daughter (his son and his wife are not skiers... yet).
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/94291553667
Passcode: NICO2024
About the Speaker Series:
Wednesdays@NICO is a vibrant weekly seminar series focusing broadly on the topics of complex systems, data science and network 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, May 29, 2024 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)