The universal visitation law of human mobility

Markus Schläpfer, Lei Dong, Kevin O’Keeffe, Paolo Santi, Michael Szell, Hadrien Salat, Samuel Anklesaria, Mohammad Vazifeh, Carlo Ratti & Geoffrey B. West
Nature volume 593, pages 522–527 (2021)

Human mobility impacts many aspects of a city, from its spatial structure to its response to an epidemic. It is also ultimately key to social interactions, innovation and productivity. However, our quantitative understanding of the aggregate movements of individuals remains incomplete. Existing models—such as the gravity law or the radiation model—concentrate on the purely spatial dependence of mobility flows and do not capture the varying frequencies of recurrent visits to the same locations. Here we reveal a simple and robust scaling law that captures the temporal and spatial spectrum of population movement on the basis of large-scale mobility data from diverse cities around the globe. According to this law, the number of visitors to any location decreases as the inverse square of the product of their visiting frequency and travel distance. We further show that the spatio-temporal flows to different locations give rise to prominent spatial clusters with an area distribution that follows Zipf’s law. Finally, we build an individual mobility model based on exploration and preferential return to provide a mechanistic explanation for the discovered scaling law and the emerging spatial structure. Our findings corroborate long-standing conjectures in human geography (such as central place theory and Weber’s theory of emergent optimality) and allow for predictions of recurrent flows, providing a basis for applications in urban planning, traffic engineering and the mitigation of epidemic diseases.

Read the full article at: www.nature.com

Why AI is harder than we think. Melanie Mitchell. Santa Fe Institute


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Since its beginning in the 1950s, the field of artificial intelligence has cycled several times between periods of optimistic predictions and massive investment (“AI Spring”) and periods of disappointment, loss of confidence, and reduced funding (“AI Winter”). Even with today’s seemingly fast pace of AI breakthroughs, the development of long-promised technologies such as self-driving cars and housekeeping robots has turned out to be much harder than we thought.

One reason for these repeating cycles is a lack of understanding of the nature and complexity of intelligence itself. In this talk I will discuss some fallacies in common assumptions made by AI researchers, which can lead to overconfident predictions about the field. I will also speculate on what is needed for the grand challenge of making AI systems more robust, general, and adaptable—in short, more intelligent.

Speaker Bio: Melanie Mitchell is the Davis Professor of Complexity at the Santa Fe Institute, and Professor of Computer Science (currently on leave) at Portland State University. Her current research focuses on conceptual abstraction, analogy-making, and visual recognition in artificial intelligence systems. Melanie is the author or editor of six books and numerous scholarly papers in the fields of artificial intelligence, cognitive science, and complex systems. Her book Complexity: A Guided Tour (Oxford University Press) won the 2010 Phi Beta Kappa Science Book Award and was named by Amazon.com as one of the ten best science books of 2009. Her latest book is Artificial Intelligence: A Guide for Thinking Humans (Farrar, Straus, and Giroux).

Watch at: www.youtube.com

Machine learning Perspectives for Complex Networks. @CCS2021L

Networks provide a simple model to understand and predict the emergent behavior of complex systems made of a large number of interacting nonlinear dynamical units. Some of the most challenging and useful problems in network science focus on how structural properties of the underlying interaction network govern the collective dynamical behavior on the network, and how these rules can be discovered from real-world data. The rapid advancement of new machine learning techniques has led to the development of new algorithms and strategies for inference of underlying network structures in datasets, prediction of behavior of complex and dynamical networks, and identification and control of such networks.
In this second installment of the satellite, we are covering topics like machine-learning-based network inference problems, analysis of social networking and human behavior data, and prediction of behavior of complex systems. Social data analysis has emerged as an important topic in the recent years because we have seen a rapid growth of online polarization, and also because new data has been available for human social interactions. Using machine learning for dynamical systems has become important in fields like global climate prediction, and relevant for accelerating state-of-the-art simulations of complex systems.
This satellite meeting aims to bring together the network scientists having expertise in traditional approaches and expert machine learning scientists for exchange of ideas, and formation of a platform for future collaboration, as well as to deliberate upon open problems in the network science which can be addressed by machine learning techniques.

More at: sites.google.com

Artificial life: sustainable self-replicating systems

Carlos Gershenson, Jitka Cejkova
Nature has found one method of organizing living matter, but maybe there are also other options — not yet discovered — on how to create life. To study the life as it could be is the objective of an interdisciplinary field called Artificial Life (commonly abbreviated as ALife). The word “artificial” refers to the fact that humans are involved in the creation process. The results might be completely unlike natural forms of life, not only because of their chemical composition, but even some computer programs exhibiting life-like behaviours interest ALife researchers.

Read the full article at: arxiv.org

CASMOS2021: Workshop on Complex Adaptive System Approaches in Management and Organization Science. Online Satellite @CCS2021L

This workshop is co-located with the Conference on Complex Systems and is interested in novel and innovative applications of complex adaptive system approaches to rising questions in the field of Management and Organization Science. The aim of the workshop is to facilitate the meeting of people who work in the field of Management and Organization Science (as well as adjacent areas) and who employ complex adaptive system approaches. We aim at providing a multidisciplinary forum for the presentation and discussion of recent research findings. The workshop has the ultimate objectives to bridge the gap between Management and Organization Science and Complexity Science, and to promote thereby the further development of Management and Organization Science with a specific emphasis to dynamics and emergent behaviors.

More at: casmos.github.io