Ontology-Based Framework for the Automatic Recognition of Activities of Daily Living Using Class Expression Learning Techniques

Table 2

Features of existing ADL ontologies.

	Salguero et al. [3]	SPHERE [21]	COSAR [22]	Noor [23]	Chen and Nugent [24]	Bae [7]	Hois [25]	ODI [26]	SOCOM [27]
Approach	DDA	KDA	Hybrid	KDA	KDA/hybrid	KDA	KDA	KDA	KDA
Format	OWL	OBO	OWL	OWL	OWL	OWL	OWL	OWL	OWL
Sensor events	✓	✓	✓	✓			✓		✓
Ordered events	✓
Overlapped activities		✓	✓
Multiagent			✓			✓
Locations		✓	✓	✓	✓	✓	✓	✓	✓
Sensors hierarchy		✓	✓		✓	✓			✓
Composite activities		✓		✓	✓
Posture		✓	✓	✓
Enriched properties	✓			✓		✓
Available	✓	✓	✓	✓

Although sensor events are not explicitly defined, we can consider atomic activities as such in this model since each atomic activity is directly related to the activation or deactivation of a single sensor.