Events
Past Event
Wednesdays@NICO Seminar: Community Structure in Complex Networks
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level Chambers Hall
Details
Community Structure in Complex Networks
Santo Fortunato, Professor of Complex Systems, Department of Biomedical Engineering and Computational Science, Aalto University
Abstract
Complex systems typically display a modular structure, as modules are easier to assemble than the individual units of the system, and more resilient to failures. In the network representation of complex systems, modules, or communities, appear as subgraphs whose nodes have an appreciably larger probability to get connected to each other than to other nodes of the network. In this talk I will address three fundamental questions: How is community structure generated? How to detect it? How to test the performance of community detection algorithms? I will show that communities emerge naturally in growing network models favoring triadic closure, a mechanism necessary to implement for the generation of large classes of systems, like e.g., social networks. I will discuss the limits of the most popular class of clustering algorithms, those based on the optimization of a global quality function, like modularity maximization. Testing algorithms is probably the single most important issue of network community detection, as it implicitly involves the concept of community, which is still controversial. I will discuss the importance of using realistic benchmark graphs with built-in community structure.
Bio
Santo Fortunato is Professor of Complex Systems at the Department of Computer Science of Aalto University, Finland. Previously he was director of the Sociophysics Laboratory at the Institute for Scientific Interchange in Turin, Italy. Prof. Fortunato got his PhD in Theoretical Particle Physics at the University of Bielefeld In Germany. He then moved to the field of complex systems, via a postdoctoral appointment at the School of Informatics and Computing of Indiana University. His current focus areas are network science, especially community detection in graphs, computational social science and science of science. His research has been published in leading journals, including Nature, PNAS, Physical Review Letters, Reviews of Modern Physics, Physics Reports and has collected about 15,000 citations (Google Scholar). His review article Community detection in graphs (Physics Reports 486, 75-174, 2010) is the most cited paper on networks of the last years. He received the Young Scientist Award for Socio- and Econophysics 2011, a prize given by the German Physical Society, for his outstanding contributions to the physics of social systems.
Time
Wednesday, February 24, 2016 at 12:00 PM - 1:00 PM
Location
Lower Level Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Lightning Talks w/ Northwestern Scholars!
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speakers:
Yessica Herrera, Visiting Scholar, Northwestern Institute on Complex Systems
Talk Title: The Body Speaks: Visual Patterns of Psychological Stress
Aakriti Kumar, Post-Doctoral Fellow, Northwestern Institute on Complex Systems
Talk Title: Evaluating Elements of Empathic Communication with Experts, Crowds, and Large Language Models
Tingyu "Mark" Zhao, PhD Student, Industrial Engineering and Management Sciences
Talk Title: Noise Filtering in Complex Networks
Sign Up:
Sign up to present at a future Lightning Talk session. NICO Lightning Talks are open to graduate students, postdoctoral fellows, and visiting scholars.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/95387714084
Passcode: NICO25
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 14, 2025 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)
WED@NICO SEMINAR: Rosemary Braun, Northwestern University "The Scale of Life"
Northwestern Institute on Complex Systems (NICO)
12:00 PM
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Lower Level, Chambers Hall
Details
Speaker:
Rosemary Braun, Associate Professor, Department of Molecular Biosciences, Northwestern University
Title:
The Scale of Life
Abstract:
Living systems exhibit surprising and beautiful self-organization at all scales. At the atomic level, proteins self-assemble into macromolecular complexes. The function of these machines is orchestrated within the cell by regulatory networks, whose activity is in turn dictated by, and coordinated with, the cells environment. This coordination takes place across large spans of space and time: the size and lifetime of organisms as large as the blue whale. Populations and ecosystems of many organisms in turn exhibit remarkable emergent dynamics. Today, advances in single-cell assays enable us to probe the molecular state of every cell in a sample in high-dimensional detail. But is this the correct scale at which to probe living systems? What can we learn from this data, and how can we abstract from the microscopic details to macroscopic phenotypes? In this talk, I will discuss some of our recent work bridging the cell and tissue/organism scales, and discuss some challenges and opportunities for the future.
Speaker Bio:
Rosemary Braun is an Associate Professor of Molecular Biosciences, Applied Mathematics [ESAM], and Physics at Northwestern University. A theoretical physicist by training, she earned her PhD in Physics from the University of Illinois, followed by a Masters in Biostatistics from Johns Hopkins University. She completed her postdoctoral training at the National Cancer Institute (NIH) before joining Northwestern as a faculty member. Today, she works at the intersection of statistics, mathematics, and biology to develop computational tools for analyzing high-dimensional data. In addition to her Northwestern affiliations, she is also Associate Director of the National Institute for Theory and Mathematics in Biology, as well as external faculty of the Santa Fe Institute.
Location:
In person: Chambers Hall, 600 Foster Street, Lower Level
Remote option: https://northwestern.zoom.us/j/97015976754
Passcode: NICO25
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 21, 2025 at 12:00 PM - 1:00 PM
Location
Lower Level, Chambers Hall Map
Contact
Calendar
Northwestern Institute on Complex Systems (NICO)