New Trends in Analysis and Control of Complex Networks

Lucca, Italy
September 25, 2014

Invited speakers

Scientific Committee


Last update: September 17, 2014


New Trends in Analysis and Control of Complex Networks

Lucca, Italy, September 25, 2014


A Satellite Meeting of the
ECCS'14 - European Conference on Complex Systems
Lucca, Italy, September 22-26, 2014

Organized by
Mario Di Bernardo, University of Bristol and
University of Naples "Federico II" [web]
Carlo Piccardi, Politecnico di Milano [web]

Technical sponsorship by
SICC SICC - Italian Society for Chaos and Complexity

The interest on networks has dramatically increased in the last fifteen years, since it has been recognized that the network formalism is the best approach for dealing with complex systems made by discrete, interacting units like individuals, companies, computers, etc. Although plenty of methods of analysis have been developed, and many phenomena that crucially characterize network structures and dynamics can now be studied in a rigorous way, the challenge of the next decade is to transform the 'networks science' from a set of elegant theoretical results to a powerful toolbox for the everyday activity of scientists and engineers. A specific field where this development is more urgent is control, as the control and the 'network science' communities have put in common their rich theoretical knowledge only to a very little extent.

The Satellite Meeting will be a forum for discussing recent advances in the study of network analysis and control. The workshop is intended to be fully interdisciplinary, and bring together both theoretical studies and applications to any field of science and engineering.

Particular attention will be devoted to the following topics:
  • Control and identification of complex networks
  • Consensus and synchronization on networks 
  • Methods of dynamical systems and control theory applied to network analysis
  • Methods of network analysis applied to control problems
  • Networked control systems
  • Robustness of uncertain networked systems

The Satellite Meeting will be hosted by ECCS'14 and will be co-located with the main conference at IMT Institute for Advanced Studies, Lucca.


Takaaki Aoki

Takaaki Aoki

Kagawa University

Organization of adaptive networks as a dynamical system
Real-world networks are not static, but continuously change to meet the evolving needs of society. To manage and control such dynamic networks, we have to understand the nature of the adaptively changing networks, in which the reformation of the networks and the dynamical processes occurring on the network are interdependent.
We considered a simple model of co-evolving network dynamics, combining the dynamics of random walkers and the dynamics of weighted connections which are regulated by the traffic of the walkers, and analyzed the organization of the network as a dynamical system.
Under suitable conditions, the density of the walkers and the link weights converged to stationary power-law distributions at the macroscopic level. However, they continued to change with time at the microscopic level, even though the dynamics of the proposed model is completely deterministic without any random processes. We numerically and theoretically analyzed the equilibrium states from perspective of the dynamical system and found that the system has multi-stability including chaotic states.
Alberto Bemporad

Alberto Bemporad

IMT Institute for Advanced Studies, Lucca [web]

Stochastic economic model predictive control of complex drinking water networks
Drinking water networks are a real-life example of dynamical networks that include a large number of nodes and are affected by uncertainty. In this talk we consider the goal of controlling the operational management of possibly hundreds of tanks, pumping stations and demand nodes, under uncertain upcoming demand, in an economically profitable and risk-averse way. State-of-the-art time series analysis methods are used to produce 24-hours ahead hourly estimates of water demand. The uncertainty of these estimates is represented in the form of scenario trees; the approach is entirely data driven and no assumptions are imposed on the respective probability distribution functions. We develop stochastic model predictive control (SMPC) methods taking into account the volatility associated with water demand. The SMPC problem is solved on an hourly basis in a receding horizon fashion to optimally decide current pumping actions and valve positions aiming at a smooth and economic network operation that accounts for the constraints on tank capacities, pumping capabilities, and pressures. Certain performance indicators are chosen to evaluate the closed-loop behavior of the controlled system. The formulated MPC problem gives rise to a large-scale yet well-structured QP problem, which can be solved efficiently and in a distributed manner by exploiting the separable structure of its dual, thus enabling the real-time application of such a control system.
Yang-Yu Liu

Yang-Yu Liu

Harvard University [web]
Controllability and observability of complex systems
The ultimate proof of our understanding of complex systems is reflected in our ability to control them. Although control theory offers mathematical tools for steering engineered systems towards a desired state, a framework to control complex systems is lacking. In this talk I will show that many dynamic properties of complex systems can be quantitatively studied, via a combination of tools from control theory, network science and statistical physics. In particular, I will focus on two dual concepts, i.e. controllability and observability, of general complex systems. Controllability concerns our ability to drive the system from any initial state to any final state within finite time, while observability concerns the possibility to deduce the system’s internal state from observing its input-output behavior. I will show that by exploring the underlying network structure of complex systems one can determine the driver (or sensor) nodes that with time-dependent inputs (or measurements) will enable us to fully control (or observe) the whole system.
Roberto Tempo

Roberto Tempo

CNR-IEIIT, Politecnico di Torino [web]
Distributed randomized algorithms in social and sensor networks
We study a new model of opinion dynamics in social networks which has two main features. First, agents asynchronously interact in pairs, and these pairs are chosen according to a random process. Following recent literature, we refer to this communication model as "gossiping''. Second, agents are not completely open-minded, but instead they take into account their initial opinions, which may be thought of as their "prejudices''. In the literature, such agents are often called "stubborn". We show that the opinions of the agents fail to converge, but persistently undergo ergodic oscillations, which asymptotically concentrate around a mean distribution of opinions. This mean value is exactly the limit of the synchronous dynamics of the expected opinions.
In the second part of the talk, we demonstrate how a modified version of this approach is useful in sensor networks. In particular, we consider two problems: clock synchronization and optimal coverage. In both cases, the solution is obtained by means of a distributed least-squares randomized algorithm, provided that a suitable time-averaging operation is performed.
Sandro Zampieri

Sandro Zampieri

University of Padova [web]
Controllability metrics, limitations and algorithms for complex networks
This presentation will consider the problem of controlling complex networks, i.e., the joint problem of selecting a set of control nodes and of designing a control input to steer a network to a target state. For this problem, 1) we propose a metric to quantify the difficulty of the control problem as a function of the required control energy, 2) we derive bounds based on the system dynamics (network topology and weights) to characterize the tradeoff between the control energy and the number of control nodes, and 3) we propose an open-loop control strategy with performance guarantees. In our strategy, we select control nodes by relying on network partitioning, and we design the control input by leveraging optimal and distributed control techniques. Our findings show several control limitations and properties. For instance, for Schur stable and symmetric networks: 1) if the number of control nodes is constant, then the control energy increases exponentially with the number of network nodes; 2) if the number of control nodes is a fixed fraction of the network nodes, then certain networks can be controlled with constant energy independently of the network dimension; and 3) clustered networks may be easier to control because, for sufficiently many control nodes, the control energy depends only on the controllability properties of the clusters and on their coupling strength. We validate our results with examples from power networks, social networks and epidemics spreading.



Takaaki Aoki, Kagawa University [web]
Dario Bauso, University of Palermo [web]
Alberto Bemporad,
IMT Institute for Advanced Studies, Lucca [web]
Guanrong Chen,
City University of Hong Kong [web]
Mario Di Bernardo,
University of Bristol and University of Naples "Federico II" [web]
Hideaki Ishii, Tokio Institute of Technology [web]
Yang-Yu Liu,
Harvard University [web]
Antonis Papachristodoulou,
University of Oxford [web]
Carlo Piccardi,
Politecnico di Milano [web]
Roberto Tempo, CNR-IEIIT, Politecnico di Torino [web]



Please notice that time scheduling might be modified. Check frequently for updates.

The abstracts of the invited talks are above in this page. The abstract of the contributed talks are available here.

Thursday, September 25, 2014, Villa Bottini (invited talks = 45min, contributed talks = 15min)

8:50 - 9:00 
opening of the meeting

morning session, chair: Carlo Piccardi
9:00 - 9:50 
invited talk: Controllability and observability of complex systems
Yang-Yu Liu
9:50 - 10:10 
Local and global dynamics of complex systems: when does the network structure matter?
Jean-Charles Delvenne, Renaud Lambiotte, Luis E.C. Rocha
10:10 - 11:00 
invited talk: Controllability metrics, limitations and algorithms for complex networks
Sandro Zampieri
coffee break
11:30 - 11:50  Bayesian estimation of simple models for networked oscillators based on experimental data
Kaiichiro Ota, Toshio Aoyagi
11:50 - 12:40 
invited talk: Distributed randomized algorithms in social and sensor networks
Roberto Tempo
12:40 - 13:00 
Dynamics and control of game interactions on complex networks
Dario Madeo, Chiara Mocenni


afternoon session, chair: Mario Di Bernardo
14:30 - 15:20 
invited talk: Organization of adaptive networks as a dynamical system
Takaaki Aoki
15:20 - 15:40 
Speed-gradient control of cluster synchronization by adaptation of network topology
Philipp Hövel, Judith Lehnert, Anton Selivanov, Alexander Fradkov, Eckehard Sch
15:40 - 16:00 
Motion control of Vicsek's agents in an inhomogeneous space
Arturo Buscarino, Luigi Fortuna, Mattia Frasca, Alessandro Rizzo
16:00 - 16:20 
Event-triggered pinning control of switching networks
Antonio Adaldo, Francesco Alderisio, Davide Liuzza, Guodong Shi, Dimos V. Dimarogonas, Mario di
Bernardo, Karl Henrik Johansson
16:20 - 17:10 
invited talk: Stochastic economic model predictive control of complex drinking water networks
Alberto Bemporad, Ajay Kumar Sampathirao, Pantelis Sopasakis

conclusion of the meeting, and coffee break



All the participants in the Satellite Meeting (with or without talk) have to register to ECCS'14.

For registration, go to ECCS'14 registration webpage.



The Satellite meeting will be hosted by ECCS'14 and will be co-located with the main conference at IMT Institute for Advanced Studies, Lucca, Italy.

The Satellite Meeting will take place in Villa Bottini (see here for directions - a detailed map is available).