Semantic Time Geography: Bringing Semantic Contexts to Notation System of Time Geography

Time geography is a powerful framework. It provides an elegant notation system with a series of well-defined space–time entities and relationships for representing human activity-travel behaviors under various space–time constraints. The classical time-geographical framework focuses on only the geometric 1aspect of activity-travel behaviors in the physical space but ignores semantic information about activity-travel behaviors in the hybrid cyber–physical space (e.g., activity goals, transport modes, and personal emotions and satisfaction). This study proposes a novel framework of semantic time geography by introducing a series of semantically enriched time-geographical entities (e.g., semantic space–time paths, prisms, lifelines, and projects) and relationships (e.g., semantic space–time intersection relationships) in the hybrid cyber–physical space. The proposed framework is implemented by using the relational database and integrated with an existing geographic information systems platform. A new semantic accessibility measure is introduced to illustrate the applicability of the proposed framework. Experimental results demonstrate the capabilities of the introduced entities and relationships for representing, visualizing, querying, and analyzing both space–time and semantic dimensions of human activity-travel behaviors in the hybrid cyber–physical space.