In the study of epileptic seizure or epileptic attack, a strategy receiving increased attention is the use of nonlinear methods in detecting the earliest dynamical changes preceding seizures. The methods usually consider continuous EEG measurements from epileptic patients to predict and...

This paper examines the interplay of opinion exchange dynamics and communication network formation. An opinion formation procedure is introduced which is based on an abstract representation of opinions as k-dimensional bitstrings. Individuals interact if the difference in the opinion strings is...

This paper investigates the dynamics of stocks in the S&P500 index for the last 30 years. Using a stochastic geometry technique, we investigate the evolution of the market space and define a new measure for that purpose, which is a robust index of the dynamics of the market structure and...

This paper investigates the dynamics of stocks in the S&P500 for the last 33 years, considering the population of all companies present in the index for the whole period. Using a stochastic geometry tech- nique and defining a robust index of the dynamics of the market struc- ture, which is able...

This paper contributes to further understanding the economic performance of Portuguese and Spanish regions, using a stochastic network approach. The empirical analysis is made at the territorial level of NUT 3 regions and covers the period 1995-2008. The performance of regions is based on GDP...

A model is developed to study the effectiveness of innovation and its impact on structure creation and structure change on agent-based societies. The abstract model that is developed is easily adapted to any particular field. In any interacting environment, the agents receive something from the...

Following the definition of systemic risk by the Financial Stability Board, the International Monetary Fund and the Bank for International Settlements, this paper proposes a method able to simultaneously address the two dimensions in which this risk materializes: namely the cross-sectional and...

Many complex systems display fluctuations between alternative states in correspondence to tipping points. These critical shifts are usually associated with generic empirical phenomena such as strengthening correlations between entities composing the system. In finance, for instance, market...

The present paper introduces an up-to-date methodology to detect Early Warning Signals of critical transitions, that manifest when distress stages in financial markets are about to take place. As a first step, we demonstrate that a high-dimensional dynamical system can be formulated in a simpler...