Pervasive computing applications have unique characteristics that preclude the use of traditional access control models, such as Role-Based Access Control (RBAC), for their protection. Such models do not take into account contextual information before making access decisions and cannot handle the dynamism inherent in pervasive computing applications. Towards this end, we propose new spatio-temp...

This paper presents Timed Quorum System (TQS), a quorum system for large-scale and dynamic systems. TQS provides guarantees that two quorums, accessed at instances of time that are close together, intersect with high probability. We present an algorithm that implements TQS at its core and that provides operations that respect atomicity with high probability. This TQS implementation has quorums ...

The advent of smartphones in recent years has changed the wireless landscape. Smartphones have become a platform for online user interface to cloud databases. Cloud databases may provide a large set of userprivate and sensitive data (i.e., objects), while smartphone users (i.e., subjects) provide location-sensitive information. Secure and private services in wireless accessing to cloud database...

The advent of smartphones in recent years has changed the wireless landscape. Smartphones have become a platform for online user interface to cloud databases. Cloud databases may provide a large set of user-private and sensitive data (i.e., objects), while smartphone users (i.e., subjects) provide locationsensitive information. Secure and private services in wireless accessing to cloud database...

Information systems (IS) building, as described in the literature, consist of two main phases: IS strategic planning and IS development. The IS strategic planning phase is performed every few years and produces a long-term strategic plan. The IS development phase is performed annually by IS management and produces a development plan for the next year and outlines development activities. The act...

Recently, distributed processing of large dynamic graphs has become very popular, especially in certain domains such as social network analysis, Web graph analysis and spatial network analysis. In this context, many distributed/parallel graph processing systems have been proposed, such as Pregel, GraphLab, and Trinity. These systems can be divided into two categories: (1) vertex-centric and (2)...

Over the past few years we have been developing an expressive embodied conversational agent system. In particular, we have developed a model of multimodal behaviours that includes dynamism and complex facial expressions. The first feature refers to the qualitative execution of behaviours. Our model is based on perceptual studies and encompasses several parameters that modulate multimodal behavi...

We describe the structure of a workflow as a graph whose vertices represent tasks and the arcs are associated to workflow transitions in this paper. To each task an input/output logic operator is associated. Furthermore, we associate a Boolean term to each transition present in the workflow. We still identify the structure of workflows and describe their dynamism through the construction of new...

We describe a general framework for modeling and stochastic simulation of epidemics in realistic dynamic social networks, which incorporates heterogeneity in the types of individuals, types of interconnecting risk-bearing relationships, and types of pathogens transmitted across them. Dynamism is supported through arrival and departure processes, continuous restructuring of risk relationships, a...

The paper proposes three ‘non-conventional’ patterns to model using System Dynamics: (i) transformational dynamism of civil society organizations; (ii) regulations effectively limiting disruptive effects of platform firms; (iii) policies facilitating new patterns of value creation through genuine sharing. The combination of SD and Agent Base Modelling may improve the effectiveness of analysing ...