SIMULATION

The authors propose a small-world network model that combines cellular automata with the social mirror identities of daily-contact networks for purposes of performing epidemiological simulations. The social mirror identity concept was established to integrate human long-distance movement and daily visits to fixed locations. After showing that the model is capable of displaying such small-world effects as low degree of separation and relatively high degree of clustering on a societal level, the authors offer proof of its ability to display R ₀ properties—considered central to all epidemiological studies. To test their model, they simulated the 2003 severe acute respiratory syndrome (SARS) outbreak.

The authors present an agent-based model representing a policy process among stakeholders of river management. For evaluating the different river management alternatives, the agent-based model is coupled to an integrated river model that describes the impacts of river management, such as flood risk, nature development, and costs. The model is applied to the case of the ongoing Dutch river management project “Grensmaas.” The authors analyze stakeholder support and reconstruct the observed policy outcomes of the Grensmaas project over the past 15 years to provide a first validation of the model. They then assess how stakeholder support and the policy outcome might change when stakeholders would change their preference structures or take climate change into account. They argue that the main virtue of the developed modeling framework lies in its application within participatory processes, to support stakeholders to reflect on their goals and uncertainty perspectives in a social context.

Some types of animals exploit patterns created in the environment as external mental states, thus obtaining an extension of their mind. In the case of social animals, the creation and exploitation of such patterns can be shared, which supports a form of shared extended mind or collective intelligence. This article explores this shared extended mind principle for social animals in more detail. The focus is on formal analysis and formalization of the dynamic properties of the processes involved, both at the local level (the basic mechanisms) and the global level (the emerging properties of the whole), and their relationships. A case study in social ant behavior in which the shared extended mind plays an important role is used as an illustration. For this case, simulations are described based on specifications of local properties, and global properties are specified and verified.