Method and apparatus for discovering social ties based on cloaked trajectories

An apparatus comprising:

• at least one processor;
• and
• at least one memory including computer program code,
• the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least:
• transform cloaked regions of a first trajectory of a first user and cloaked regions of a second trajectory of a second user to corresponding semantic regions, respectively, wherein a semantic region is expressed with a semantic meaning of a corresponding cloaked region;
• map the transformed semantic regions to nodes of a hierarchical semantic tree, wherein each node of the hierarchical semantic tree corresponds to a semantic region;
• and
• determine that a social tie exists between the first user and the second user based on relationships between nodes mapped to semantic regions of the first trajectory and nodes mapped to semantic regions of the second trajectory.

A non-transitory computer-readable storage medium carrying one or more sequences of one or more instructions which, when executed by one or more processors, causing an apparatus to:

• transform cloaked regions of a first trajectory of a first user and cloaked regions of a second trajectory of a second user to corresponding semantic regions, respectively, wherein a semantic region is expressed with a semantic meaning of a corresponding cloaked region;
• map the semantic regions to nodes of a hierarchical semantic tree, wherein each node of the hierarchical semantic tree corresponds to a semantic region;
• and
• determine that a social tie exists between the first user and the second user based on relationships between nodes mapped to semantic regions of the first trajectory and nodes mapped to semantic regions of the second trajectory.