Problem solving and argumentation in probability context: analysis of some examples of necessary object-level narratives

The introduction to probabilistic thinking in primary and middle school is one of the goals delineated by the Italian National Curriculum Guidelines and is part of the curricula of other countries. The paper presents activities carried out in Italian classes from grades 3 to 8 in which the introduction to probabilistic thinking is structured through problem solving and argumentation activities. The mathematical claims developed by the students were examined through a qualitative analysis, id...

Accountability-Preserving Anonymous Delivery of Cloud Services

Range query integrity in cloud data streams with efficient insertion

Cloud computing provides users with the possibility to store their data in third-party servers. These data centers may be untrusted or susceptible to attacks, hence they could return compromised query results once interrogated. Query integrity has been widely investigated in the literature, and a number of methods have been proposed to allow users to verify that query results are complete (i.e., no qualifying tuples are omitted), fresh (i.e., the newest version of the results are returned), a...

Measuring betweenness centrality in social internetworking scenarios

The importance of the betweenness centrality measure in (on-line) social networks is well known, as well as its possible applications to various domains. However, the classical notion of betweenness centrality is not able to capture the centrality of nodes w.r.t. paths crossing different social networks. In other words, it is not able to detect those nodes of a multi-social-network scenario (called Social Internetworking Scenario) which play a central role in inter-social-network information ...