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PhD proposal - Semantic Interoperability in the Constrained Semantic Web of Things


Semantic Interoperability, Semantic Web, Linked Data, Web of Things


Master in computer Science with good theoretical and practical knowledge of Semantic Web Technologies. Programming skills.


Applications should be submitted by e-mail to antoine.zimmermann@emse.fr and maxime.lefrancois@emse.fr with the reference: PhD_CoSWoT_2020

Knowledge of Semantic Web Technologies is mandatory.

The position is available immediately and application evaluation will be continuous until the position is filled. Interested candidates should submit a resume, cover letter, and master transcripts


The Internet of Things connects physical devices offering sensing or actuating with their vicinity. The ever-growing capabilities of devices allow to imagine new architectures including them as first class citizens. New added-value applications can then be envisioned in smart agriculture, smart buildings, smart cities, energy and water management, e-health and ageing well... The Web of Things (WoT) allows to describe the devices semantics, bridging the gap between the different domain and service descriptions. In today WoT architectures, physical devices can be located at distance from systems that perform reasoning. A centralised approach does not take advantage of the devices capabilities and induces suboptimal data transfers as well as server overload. Besides, many devices are now smart enough to discover each other, exchange data, and collectively make decisions.

The scientific context of this Ph.D. thesis is the French ANR project CoSWoT (Constrained Semantic Web of Things), whose objectives are to propose a distributed WoT-enabled software architecture embedded on constrained devices with two main characteristics: (1) it will use ontologies to specify declaratively the application logic of devices and the semantics of the exchanged messages; (2) it will add reasoning functionalities to devices, so as to distribute processing tasks among them. Doing so, the ambition of the CoSWoT project is to greatly simplify the development of applications including devices of the WoT, by enabling the development and execution of intelligent and decentralised smart WoT applications despite the heterogeneity of devices.

Scientific Objectives

This Ph.D. focuses on the problem of semantic interoperability at the data level between heterogeneous and potentially constrained things and services.

Many data formats and data models exist and even compete with each other for adoption in IoT platforms. The semantic interoperability problem can be tackled by standardizing data formats and service APIs [ierc15]. One objective of this Ph.D. is to tackle semantic interoperability despite the heterogeneity of data formats and service API specifications, i.e., across platforms.

Furthermore, the use of Semantic Web technologies has been investigated to facilitate semantic interoperability among platforms. The second objective of the Ph.D. is to investigate how semantic interoperability can be obtained between devices directly, instead of between platforms.

Semantic interoperability between non-constrained systems can be solved by developing ontologies [Obr03]. However, when devices are constrained, already deployed, or follow one of the aforementioned specifications, additional adapted ontologies and technologies must be proposed for devices to understand the exchanged messages despite heterogeneity [Lef18]. One possible direction for this thesis is to compare existing approaches on some benchmarks consisting of ecosystems of heterogeneous synthetic services and devices. Starting points to achieve semantic flexibility are the W3C Thing Description, Content and Profile Negotiation [Fie14,Sve19], and the RDF Presentation conceptual framework [Lef18].

Scientific and Industrial Impact

This thesis and the CoSWoT project aim to contribute to fostering the decoupling of the development of software and the development of hardware, so as to ease the emergence of a new economic sector in the digital industry around WoT applications development, disconnected from the development of the smart devices themselves.