A Multi-agent Based Digital Preservation Model

The thesis describes an agent-based model aimed to simulate those processes in which a digital object faces the risk of obsolescence, a migration process has to be performed and the most appropriate file format has to be adopted. Agents have been designed in order to monitor and control the local system where they reside and its environment. They are able to become aware of obsolescent formats based on global parameters such as their diffusion. They communicate as well with each other to find out the most suitable preservation action to be performed. Agents request suggestions that are evaluated and propagated according to a weighting based on the level of trust assigned to both the agents who identified the problem and proposed the solution. In the current research, the definition of the trust level has been chosen based on the cultural and geographical distances, the expertise of the involved agents and the file format numerosity. The level of trust between two agents is automatically updated after every interaction by the mean of a feedback mechanism profiting of an inter agent communication based on stigmergy. Summing up, the thesis demonstrates how a multi-agent system can either perform an autonomous preservation action or suggest a list of best candidate solutions to the user. It benefits the management of several kinds of digital archive, especially those with limited resources specifically dedicated to digital preservation, such as small personal collections and many public institutions.