Half a billion simulations: Evolutionary algorithms and distributed computing for calibrating the SimpopLocal geographical model

New publication, in Environment and Planning B.


Schmitt C, Rey-Coyrehourcq S, Reuillon R, Pumain D, 2015, “Half a billion simulations: evolutionary algorithms and distributed computing for calibrating the SimpopLocal geographical model” Environment and Planning B: Planning and Design, 42(2), 300-315. http://www.envplan.com/abstract.cgi?id=b130064p

Abstract. Multiagent geographical models integrate very large numbers of spatial interactions. In order to validate these models a large amount of computing is necessary for their simulation and calibration. Here a new data-processing chain, including an automated calibration procedure, is tested on a computational grid using evolutionary algorithms. This is applied for the first time to a geographical model designed to simulate the evolution of an early urban settlement system. The method enables us to reduce the computing time and provides robust results. Using this method, we identify several parameter settings that minimize three objective functions that quantify how closely the model results match a reference pattern. As the values of each parameter in different settings are very close, this estimation considerably reduces the initial possible domain of variation of the parameters. Thus the model is a useful tool for further multiple applications in empirical historical situations.

Keywords: simulation model, multiagent system, calibration, evolutionary algorithm, geographical modelling, high-performance computing, model validation

OpenMOLE 1.0

 It’s finally there!

After 6 years of hard work we made it to 1.0 (Heroic Hippo). It combines stability and ergonomic interfaces to provide the best model exploration tool ever made. OpenMOLE is a workflow engine designed to leverage the computing power of distributed execution environments for naturally parallel processes. A process is said naturally parallel if the same computation runs many times for a set of different inputs, such as model experiment or data processing…

We are very proud of this success, that has been made possible thanks to the effort and support of a dynamic community of developers, users and also several academic funding.

This version has mostly focus on stabilization, with some novelties nevertheless:
* the distributed computing feature of OpenMOLE are now very robust and efficient,
* the evolutionary algorithm part has matured and is usable to explore models from the console API,
* a new distributed environments (SLURM) is now available.

In the next versions:
* the graphical interface will be multi-user, web based and run in the browser,
* new environments will be provided (Condor, SGE),
* advanced methods such as genetic algorithm will be usable from the graphical interface,
* it will be possible to generate console scripts from a graphical workflow,
* bootstrapping methods that quickly and automatically embed your models in OpenMOLE will be implemented.

The OpenMOLE team

European consultation on Global Systems Science

The FET (Future and Emergent Technologies) Unit of the European Commission proposes an online consultation to understand what the game-changing technologies of the next decades will be. It targets scientists, researchers, innovators, entrepreneurs and members of civil society in general and is open till 15 June 2014.

A particular consultation on “Global Systems Science” is launched with the question : “how can science support policy making on global challenges?”.

More details :

https://ec.europa.eu/digital-agenda/en/content/global-systems-science-%E2%80%93-how-can-science-support-policy-making-global-challenges

ECCS 2013 Satellite meeting

Urban Systems Modeling: advances from GeoDiverCity and MECHANICITY ERC programmes

Organizing Committee:

Denise Pumain and Arnaud Banos, UMR Géographie-cités and ERG S4 (Spatial Simulation for Social Sciences), CNRS France

pumain@parisgeo.cnrs.fr

arnaud.banos@iscipif.fr

Michael Batty, CASA, University College London, London, UK

m.batty@ucl.ac.uk

Topic:

GeoDiverCity and MECHANICITY are two projects founded by an advanced ERC Grant. Both are about spatial modelling of urban systems with a specific interest in complex systems approaches and are thus within the main area of researches that are of interest for Complex Systems Society and Conference. The GeoDiverCity programme led by Denise Pumain is analysing and modelling the geographical diversity of cities and systems of cities with applications in Europe, USA, Russia, India, China and South Africa. MECHANICITY stands for Morphology, Energy & Climate cHANge In the CITY and is a five year project lead by Mike Batty. It explores ideas about how energy flows tie the components of cities and their morphology together.

Topics covered by this meeting: Urban systems as complex systems, scaling methods, simulation models of urban systems, validation methods for multi-agents models, development of simulation platforms, spatio-temporal modeling of social systems (relevant for tracks 1-fundamentals of complex systems- 3 – infrastructure, planning and environment-  and  6 –social systems-  of ECCS2013 and possibly 2 since of massive use of ICT in model design and testing as well as urban data analysis).

Previous meetings:

This meeting will present advances in research made since the first joint workshop MECHANICITY-GeoDiverCity held in Avignon, April 24th 2012, within the framework of the AGILE Conference (on geomatic and geographical information systems)

Date:

September 19th, 2013

Schedule:

As the workshop is organised by two research teams wanting to compare their experiences, the meeting will at first introduce presentations from each team and is open to a few other selected presentations. Of course the attendance is open and we expect much of the reactions and comments of other specialists in complex system sciences.

From the GeoDiverCity team presentations will be made on use of mobile phone data for urban mobility analysis, urban networks simulation models, new developments of the series of Simpop multi-agents models (SimpopLocal and SimpopNet) as well as the OpenMOLE simulation platform.

From MECHANICITY team presentations will emphasize developments in scaling analysis, spatio-temporal modelling and vizualization tools.

Invited speakers are: Denise Pumain, Arnaud Banos, Clémentine Cottineau,  Clara Schmitt, Sébastien Rey, Elfie Swerts, Romain Reuillon, Mathieu Leclaire, Stefano Ugliano, Michael Batty, Elsa Arcaute, Robin Edwards, Anders Johansson, Sarah Sheppard, Pete Ferguson, Federico Battiston, Melanie Bosredon. Other speakers will be selected according to the available time and the theme of their presentation.

Presentations:

GeoDiverCity

Denise Pumain: Which theoretical bases for understanding the diversity of urban systems?

Clara Schmitt & Sébastien Rey: Simprocess, a method and platform for building geographical simulation models

Romain Reuillon & Mathieu Leclaire: the OpenMOLE simulation platform

Clémentine Cottineau & Paul Chapron: Back in the USSR: a series of models for simulating urban evolution

Elfie Swerts: Complex system view for comparing Indian and Chinese urban systems

Stefano Ugliano: A hypothesis of mutual repulsion for urban networks generated by multinational firms in the food processing sector

Arnaud Banos: title to be confirmed

MECHANICITY

Mike Batty:The New Science of Cities

Elsa Arcaute: Scaling laws and urban hierarchies through percolation theory

Peter Ferguson: Predicting urban activity distributions using new measures of network accessibility

Joan Serras: Testing mobility models: results of the England and Wales case study

Jiaqiu Wang: Using percolation theory to extract street networks of city cores

Roberto Murcio: Urban entropy measures