Publications associées à Dynamique des systèmes

Learning the intrinsic dynamics of spatio-temporal processes through Latent Dynamics Networks

Alfio Quarteroni, Francesco Regazzoni, Stefano Pagani

Predicting the evolution of systems with spatio-temporal dynamics in response to external stimuli is essential for scientific progress. Traditional equations-based approaches leverage first principles through the numerical approximation of differential equ ...

Nature Portfolio2024

Adaptive variational low-rank dynamics for open quantum systems

Vincenzo Savona, Luca Gravina

We introduce a model-independent method for the efficient simulation of low-entropy systems, whose dynamics can be accurately described with a limited number of states. Our method leverages the time-dependent variational principle to efficiently integrate ...

Amer Physical Soc2024

Higher-order organization of multivariate time series

Enrico Amico, Andrea Santoro

Time series analysis has proven to be a powerful method to characterize several phenomena in biology, neuroscience and economics, and to understand some of their underlying dynamical features. Several methods have been proposed for the analysis of multivar ...

NATURE PORTFOLIO2023

Exploration-based model learning with self-attention for risk-sensitive robot control

Sudong Lee

Model-based reinforcement learning for robot control offers the advantages of overcoming concerns on data collection and iterative processes for policy improvement in model-free methods. However, both methods use exploration strategy relying on heuristics ...

2023

Validation of spectral simulation tools in the context of ipRGC-influenced light responses of building occupants

Marilyne Andersen, Clotilde Marie A Pierson

With the growing awareness about ipRGC-influenced light (IIL) responses, design applications related to these responses are flourishing. To compare design options and optimize lighting conditions for building occupants, lighting simulations are typically u ...

2023

Electromagnetic forces in the time domain

Olivier Martin, Karim Achouri, Andrei Kiselev

We look beyond the standard time-average approach and investigate optical forces in the time domain. The formalism is developed for both the Abraham and Minkowski momenta, which appear to converge in the time domain. We unveil an extremely rich - and by fa ...

Optica Publishing Group2022

Exploiting Marginal Stability in Slow-Fast Quasilinear Dynamical Systems

Alessia Ferraro

The accurate investigation of many geophysical phenomena via direct numerical simulations is computationally not possible nowadays due to the huge range of spatial and temporal scales to be resolved. Therefore advances in this field rely on the development ...

EPFL2022

The cis-lunar ecosystem — A systems model and scenarios of the resource industry and its impact

Jean-Paul Richard Kneib

Lunar resources is one of the many new putative business models that may transform space logistics. Yet it competes with Earth-based resources, in a complex trade-off involving both tech development & socioeconomic dynamics. This study models the size vs. ...

2021

The effects of Prandtl number on the nonlinear dynamics of Kelvin-Helmholtz instability in two dimensions

Jeremy Peter Parker

It is known that the pitchfork bifurcation of Kelvin-Helmholtz instability occurring at minimum gradient Richardson number Ri(m) similar or equal to 1/4 in viscous stratified shear flows can be subcritical or supercritical depending on the value of the Pra ...

Cambridge University Press2021

Mass-Zero constrained dynamics and statistics for the shell model in magnetic field

Sara Bonella, Alessandro Coretti, David Daniel Girardier

In several domains of physics, including first principle simulations and classical models for polarizable systems, the minimization of an energy function with respect to a set of auxiliary variables must be performed to define the dynamics of physical degr ...

EDP Sciences, Springer2021

Introducing CRYOWRF v1.0: multiscale atmospheric flow simulations with advanced snow cover modelling

Varun Sharma, Michael Lehning, Franziska Gerber

Accurately simulating snow-cover dynamics and the snow-atmosphere coupling is of major importance for topics as wide-ranging as water resources, natural hazards and climate change impacts with consequences for sea-level rise. We present a new modelling fra ...

2023

Exploring policy change through agent-based simulation

Raphaël Klein

Policymaking is a complex process that has been studied using policy process theories almost exclusively. These theories have been built using a large number of qualitative cases. Such methods are useful for theory building but remain limited for theory ex ...

EPFL2021

Analysis and Modeling of the Dynamics of Traction Forces during Cell Polarization and their Role in the Organization of Edge Activity

Zeno Messi

The capacity to break symmetry and organize activity to move directionally is a fundamental property of eukaryotic cells. To explain the organization of cell-edge activity, models commonly rely on front-to-back gradients of functional components or regulat ...

EPFL2021

Development of free-boundary equilibrium and transport solvers for simulation and real-time interpretation of tokamak experiments

Francesco Carpanese

To exploit fusion as a source of energy, a hot and dense confined plasma is needed. This is achieved in tokamaks by actively controlling the plasma state meaning shape, position and internal kinetic profiles. This thesis addresses two topics: the developme ...

EPFL2021

Data assimilation of in situ and satellite remote sensing data to 3D hydrodynamic lake models: a case study using Delft3D-FLOW v4.03 and OpenDA v2.4

Alfred Johny Wüest, Damien Bouffard, Theo Baracchini

The understanding of physical dynamics is crucial to provide scientifically credible information on lake ecosystem management. We show how the combination of in situ observations, remote sensing data, and three-dimensional hydrodynamic (3D) numerical simul ...

2020

Propulsion and energetics of a minimal magnetic microswimmer

Ignacio Pagonabarraga Mora

In this manuscript we describe the realization of a minimal hybrid microswimmer, composed of a ferromagnetic nanorod and a paramagnetic microsphere. The unbounded pair is propelled in water upon application of a swinging magnetic field that induces a perio ...

ROYAL SOC CHEMISTRY2020

A Laplacian approach to stubborn agents and their role in opinion formation on influence networks

Melvyn Sandy Tyloo

Within the framework of a simple model for social influence, the Taylor model, we analytically investigate the role of stubborn agents in the overall opinion dynamics of networked systems. Similar to zealots, stubborn agents are biased towards a certain op ...

2020

Tapping into Multi-Faceted Human Behavior and Psychopathology Using fMRI Brain Dynamics

Dimitri Nestor Alice Van De Ville, Thomas William Arthur Bolton, Maria Giulia Preti, Elenor Morgenroth

Human behavior comprises many aspects that stand out by their dynamic nature. To quantify its neural underpinnings, time-resolved fMRI methods have blossomed over the past decade. In this review we conceptually organize a broad repertoire of dynamic analyt ...

2020

Methodologies for understanding and improving pedestrian mobility

Michel Bierlaire, Marija Nikolic, Riccardo Scarinci, Nicholas Alan Molyneaux, Yuki Oyama, Zhengchao Wang

Pedestrian mobility is at the center of urban transportation systems. Therefore, understanding it is a necessary task to improve the mobility in cities. However, pedestrian mobility is extremely complex, and advance methods are needed to capture its dynami ...

Routledge2020

Aspects of Gauge Theories Vacua

Adrien Florio

This thesis is concerned with gauge theories, their complicated vacuum and resulting effects. After an introduction to the subject, it is divided into four parts. Firstly, we treat the problem of chiral charge dynamics at finite temperature. Quantum field ...

EPFL2020