50 research outputs found

    Simulation of a trust and reputation based mitigation protocol for a black hole style attack on VANETs

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    From a security standpoint, VANETs (Vehicular ad hoc Networks) are vulnerable to attacks by malicious users, due to the decentralized and open nature of the wireless system. For many of these kinds of attacks detection is unfeasible, thus making it hard to produce security. Despite their characterization as dynamically reconfigurable networks, it is nonetheless essential to identify topology and population properties that can optimise mitigation protocols’ deployment. In this paper, we provide an algorithmic definition and simulation of a trust and mitigation based protocol to contain a Black Hole style attack on a VANET. We experimentally show its optimal working conditions: total connectivity, followed by a random network; connection to external networks; early deployment of the protocol and ranking of the message. We compare results with those of existing protocols and future work shall focus on repeated broadcasting, opportunistic message forwarding and testing on real data

    Contradictory information flow in networks with trust and distrust

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    We offer a proof system and a NetLogo simulation for trust and distrust in networks where contradictory information is shared by ranked lazy and sceptic agents. Trust and its negative are defined as properties of edges: the former is required when a message is passed bottom-up in the hierarchy or received by a sceptic agent; the latter is attributed to channels that require contradiction resolution, or whose terminal is a lazy agent. These procedures are associated with epistemic costs, respectively for confirmation and refutation. We describe the logic, illustrate the algorithms implemented in the model and then focus on experimental results concerning the analysis of epistemic costs, the role of the agents’ epistemic attitude on distrust distribution and the influence of (dis)trust in reaching consensus

    Voting, fast and slow: Ballot order and likeability effects in the Five Star Movement's 2012 online primary election

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    We document ballot order effects in the 2012 Parlamentarie, the online primary election held by the Italian Five-star Movement to select the candidate Members of Parliament in the 2013 Italian general elections. We show that candidates appearing towards the top of the screen systematically ranked higher in preferences. This effect holds controlling for candidates’ socio-demographic features. We also show that the number of competing candidates moderates ballot order effects, with a stronger penalty for candidates appearing at the bottom of the page in more crowded competitions. Finally, we show the influence of candidates’ likeability. Our results confirm for the first time that ballot order effects and likeability effects, already documented in traditional paper-based elections, are also found in online set-ups. We conclude by highlighting how the online medium, if properly leveraged, has the potential to reduce the influence of such biases

    Carbon neutral district project for regenerating a suburban area within the Reinventing Cities C40 framework

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    A multidisciplinary approach to urban regeneration is crucial when the project of suburban areas provides a functional program that includes the combination of technological, environmental, and social innovation. The Reinventing Cities C40 design contest represents an opportunity for designers to deal with the crossing topics of innovation, sustainability, and circular economy. The project proposals focus on the regeneration of urban areas with specific needs, ranging from the reconstruction of urban ecosystems to the re-weaving of fragile and damaged urbanity, to the promotion of areas devalued by functional empty. The Reinventing Cities C40 framework is supporting worldwide the cities in the renovation process, oriented in developing the abandoned areas with the aim of social, energy, and environmental resilience. The framework promotes the link between the Municipalities, the designers, and the local communities to create innovation on multiple levels, in the design process, in the architectural product, in the validation tools based furthermore on the new contractual definition of business models for social support. The renovation of the Crescenzago area in Milan, Italy, is based on an architectural project that entails an integrated mixed-use system of tower and line buildings ensuring an adequate social and housing mix and connection with the surrounding points of interest and green areas. The architectural project relates to the existing context with a synthesis between macro and micro-urban scale: territory, neighborhood, and the new district. The project moves by the definition of the open spaces that imprints the built ones and defines a direct connection with the green system, which pledges the carbon neutrality of the intervention. The site-specific proposal results from the matrix of strategic and technological transferable solutions that provide solar electricity for 82% of the energy needs and the green capture allows to achieve the zero-carbon goal of the district
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