An architecture for context-aware reactive systems based on run-time semantic models
Author and article information
Abstract
In recent years, new classes of highly dynamic, complex systems are gaining momentum. These systems are characterized by the need to express behaviors driven by external and/or internal changes, i.e. they are reactive and context-aware. These classes include, but are not limited to IoT, smart cities, cyber-physical systems and sensor networks.
An important design feature of these systems should be the ability of adapting their behavior to environment changes. This requires handling a runtime representation of the context enriched with variation points that relate different behaviors to possible changes of the representation.
In this paper, we present a reference architecture for reactive, context-aware systems able to handle contextual knowledge (that defines what the system perceives) by means of virtual sensors and able to react to environment changes by means of virtual actuators, both represented in a declarative manner through semantic web technologies. To improve the ability to react with a proper behavior to context changes (e.g. faults) that may influence the ability of the system to observe the environment, we allow the definition of logical sensors and actuators through an extension of the SSN ontology (a W3C standard). In our reference architecture a knowledge base of sensors and actuators (hosted by an RDF triple store) is bound to real world by grounding semantic elements to physical devices via REST APIs.
The proposed architecture along with the defined ontology try to address the main problems of dynamically reconfigurable systems by exploiting a declarative, queryable approach to enable runtime reconfiguration with the help of (a) semantics to support discovery in heterogeneous environment, (b) composition logic to define alternative behaviors for variation points, (c) bi-causal connection life-cycle to avoid dangling links with the external environment. The proposal is validated in a case study aimed at designing an edge node for smart buildings dedicated to cultural heritage preservation.
Cite this as
2019. An architecture for context-aware reactive systems based on run-time semantic models. PeerJ Preprints 7:e27702v1 https://doi.org/10.7287/peerj.preprints.27702v1Author comment
This is a submission to PeerJ Computer Science for review.
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Competing Interests
The authors declare that they have no competing interests.
Author Contributions
Ester Giallonardo conceived and designed the experiments, performed the experiments, analyzed the data, prepared figures and/or tables, performed the computation work, authored or reviewed drafts of the paper, approved the final draft.
Francesco Poggi conceived and designed the experiments, performed the experiments, analyzed the data, prepared figures and/or tables, performed the computation work, authored or reviewed drafts of the paper, approved the final draft.
Davide Rossi conceived and designed the experiments, performed the experiments, analyzed the data, prepared figures and/or tables, performed the computation work, authored or reviewed drafts of the paper, approved the final draft.
Eugenio Zimeo conceived and designed the experiments, performed the experiments, analyzed the data, prepared figures and/or tables, performed the computation work, authored or reviewed drafts of the paper, approved the final draft.
Data Deposition
The following information was supplied regarding data availability:
The Logical Sensors and Actuators ontology (LSA) and the examples discussed in the paper are available at:
https://sites.google.com/site/logicalsensorsactuators/
The code of the prototype instantiating the reference architecture based on the LSA ontology presented in the paper is available on GitHub at:
Funding
This research was supported by MIUR PRIN 2015 GAUSS Project and MIUR PON VASARI Project. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
