Managing Reputation in Collaborative Social Computing Applications

Reputation is a fundamental concept for making decisions about service providers. However, managing reputation in peer-to-peer distributed applications is not easy due to the lack of a central server that can compute this property from user opinions. Moreover, users have to marry this information with their individual trust in the service provider, which may be based on their past experiences, the opinions of their direct contacts, or both. This paper develops a reputation management system embedded in the Digital Avatars framework for collaborative social computing applications, using subjective logic. We show how the reputation of a given service provider can be calculated using the users’ opinions about it, and how this reputation can be explicitly represented, managed and combined with the trust that individual service requesters may have in them, in order to make better informed decisionsThis work is funded by the Spanish research projects PGC2018- 094905-B-100 and RTI2018-098780-B-I00

Modelling Digital Avatars: a tuple space approach

Preprint de: A. Pérez-Vereda, C. Canal, E. Pimentel. Modelling Digital Avatars: a tuple space approach, Science of Computer Programming, vol. 203, Elsevier, 2020, DOI: https://doi.org/10.1016/j.scico.2020.102583.The development of the Internet of Things (IoT) came with the manufacturing of a huge amount of smart things equipped with sensors for making them aware of their environment, and with network connection for allowing remote interaction with them. However, most smart things still lack enough autonomy and context-awareness, hindering them from being people-friendly and actually useful for their users' everyday tasks. IoT devices should take advantage of their sensors and smartness to react automatically to the needs of their users and to provide seamless interactions with them. Within this field, the authors work on the design of Digital Avatars, a mobile computing framework for dynamically programming interactions among smart devices. The framework is based on the virtual profile of the user, which is inferred, stored, and shared by their smartphone. The profile provides a personalized context for running scripts which interact with IoT devices. This way, smartphones become a digital avatar of the user, capable of acting as a personal and seamless interface with their IoT environment. In this work, we present a formalization of Digital Avatars by means of a Linda-based approach with multiple shared tuple spaces. By means of a case study, we show how properties of the systems can be proved, and we briefly describe an implementation of both the Digital Avatars framework and the case study

Digital Avatars: Promoting Independent Living for Older Adults

Population ageing, together with the desire to maintain an autonomous lifestyle, poses today’s societies with a challenge that technological advances can help considerably to cope with. The widespread use of smartphones and their increasing computing power and storage capacity make them the ideal tool to achieve this goal. In this paper, we present Digital Avatars, a software framework adapted to the needs of older adults who wish to preserve their lifestyle, but who require assistance through technology. Building on previous work on the People as a Service model, Digital Avatars takes advantage of a smartphone’s capabilities and services to collect information about the people who own them. To do this, it applies Complex Event Processing techniques extended with uncertainty to infer the habits, preferences, and needs of the device owner to build with them an enhanced virtual profile of the user. These virtual profiles are the mechanism for monitoring the quality of life of older adults: analyzing their patterns of activity, reminding them of medication schedules, or detecting risky situations that generate alerts to relatives, caregivers, or the community health system