Unifying pairwise interactions in complex dynamics

Oliver M. Cliff, Annie G. Bryant, Joseph T. Lizier, Naotsugu Tsuchiya & Ben D. Fulcher 
Nature Computational Science (2023)

Scientists have developed hundreds of techniques to measure the interactions between pairs of processes in complex systems, but these computational methods—from contemporaneous correlation coefficients to causal inference methods—define and formulate interactions differently, using distinct quantitative theories that remain largely disconnected. Here we introduce a large assembled library of 237 statistics of pairwise interactions, and assess their behavior on 1,053 multivariate time series from a wide range of real-world and model-generated systems. Our analysis highlights commonalities between disparate mathematical formulations of interactions, providing a unified picture of a rich interdisciplinary literature. Using three real-world case studies, we then show that simultaneously leveraging diverse methods can uncover those most suitable for addressing a given problem, facilitating interpretable understanding of the quantitative formulation of pairwise dependencies that drive successful performance. Our results and accompanying software enable comprehensive analysis of time-series interactions by drawing on decades of diverse methodological contributions.

Read the full article at: www.nature.com

The moral psychology of Artificial Intelligence

Jean-François Bonnefon Iyad Rahwan Azim Shariff

Moral psychology was shaped around three categories of agents and patients: humans, other animals, and supernatural beings. Rapid progress in Artificial Intelligence has introduced a fourth category for our moral psychology to deal with: intelligent machines. Machines can perform as moral agents, making decisions that affect the outcomes of human patients, or solving moral dilemmas without human supervi- sion. Machines can be as perceived moral patients, whose outcomes can be affected by human decisions, with important consequences for human-machine cooperation. Machines can be moral proxies, that hu- man agents and patients send as their delegates to a moral interaction, or use as a disguise in these interactions. Here we review the exper- imental literature on machines as moral agents, moral patients, and moral proxies, with a focus on recent findings and the open questions that they suggest.

Read the full article at: psyarxiv.com

Post-pandemic mobility patterns in London

Roberto Murcio, Nilufer Sari Aslam, Joana Barros

Understanding human mobility is crucial for urban and transport studies in cities. People’s daily activities provide valuable insight, such as where people live, work, shop, leisure or eat during midday or after-work hours. However, such activities are changed due to travel behaviours after COVID-19 in cities. This study examines the mobility patterns captured from mobile phone apps to explore the behavioural patterns established since the COVID-19 lockdowns triggered a series of changes in urban environments.

Read the full article at: arxiv.org

Winter Workshop on Complex Systems 2024

The Winter Workshop on Complex Systems is a one-week workshop where young researchers worldwide come together to work on interdisciplinary projects around complex systems.

The primary focus of the workshop is for participants to engage into novel research projects.

This is the 9th edition of the WWCS and it will be held in the Catalan Pyrenees from January 21st to Jan 26th 2024.

More at: wwcs2024.github.io

Catch-22s of reservoir computing

Yuanzhao Zhang and Sean P. Cornelius

Phys. Rev. Research 5, 033213

Reservoir computing (RC) is a simple and efficient model-free framework for forecasting the behavior of nonlinear dynamical systems from data. Here, we show that there exist commonly-studied systems for which leading RC frameworks struggle to learn the dynamics unless key information about the underlying system is already known. We focus on the important problem of basin prediction—determining which attractor a system will converge to from its initial conditions. First, we show that the predictions of standard RC models (echo state networks) depend critically on warm-up time, requiring a warm-up trajectory containing almost the entire transient in order to identify the correct attractor. Accordingly, we turn to next-generation reservoir computing (NGRC), an attractive variant of RC that requires negligible warm-up time. By incorporating the exact nonlinearities in the original equations, we show that NGRC can accurately reconstruct intricate and high-dimensional basins of attraction, even with sparse training data (e.g., a single transient trajectory). Yet, a tiny uncertainty in the exact nonlinearity can render prediction accuracy no better than chance. Our results highlight the challenges faced by data-driven methods in learning the dynamics of multistable systems and suggest potential avenues to make these approaches more robust.

Read the full article at: link.aps.org