Automatic Fare Collection (AFC) systems calculate the fare that the users must pay depending on the time of service (time-based) or the points of entrance and exit of the system (distance-based). The progressive introduction of Information and Communication Technologies (ICT) allows the use of electronic tickets, which helps to reduce costs and improve the control ...

Micro-aggregation is a clustering problem with minimum size constraints on the resulting clusters or groups; the number of groups is unconstrained and the within-group homogeneity should be maximized. In the context of privacy in statistical databases, micro-aggregation is a well-known approach to obtaining anonymized versions of confidential microdata. Optimally solving micro-aggregation on multivariate data sets ...