This is a pluggable extension for the smart envrionment solution in the EU GreenerBuildings project.
The context model of the original solution is a spatial model, i.e., all the objects are correlated based on the inclusion of locations. For example, an actuator named room1.blinds1 indicates that it is the Blinds No. 1 inside the Room No. 1. It also has an attribute location stating floor3.room1, which denotes the room this actuator stays in is also contained in the Floor No. 3. Hence, all the sensors and actuators are organized hierarchically according to their locations.
However, this spatial model exhibits weakness in terms of relationships and reasoning: it has a rather limited expressivity for relationships between objects (only spatial inclusion), cannot derive new facts from existing context data, and does not support consistency verification. In contrast, it is believed that ontology-based models are specialized in coping with such requirements decently.
Since the GreenerBuildings has provided a complete solution, it is not trivial and realistic to reform the entire system. Compared with reconstruction, a better idea is extension: in order to minimize the modification to the original architecture and implementation, a proposal comes up by developing a hybrid solution where the original context model remains unchanged, and an independent and pluggable component operates an ontology to manage the context knowledge and provide services to other components, which leads to the implementation of this "pluggable ontology construction service".
The demonstrator of this plugin is implemented as a Web service with Jersey REST API and a Jetty server is responsible for running it. The communication between this plugin and other smart environment components (including Context and Rule Maintenance Engine in GreenerBuildings' implementation) are based on messaging service RabbitMQ. The ontology of the environment is generated dynamically according to all the incoming state changes of the environment. Since message queue ensures integrity and order, the ontology of the smart environment will be always consistent with the current environment state. Then all the information contained in this ontology can be used for other further usages such as activity recognition, information enrichment, query and search, etc.
The Web UIs for consuming this service can be found in the repository rme-web.
The author is not authorized to share the source code of the other components from GreenerBuildings project for running a complete smart environment. Please contact the author for further research and questions.
* JDK (>=6)
* Maven
* RabbitMQ Server
git clone this repository
cd to the root directory of this repository
mvn jetty:run