Technological evolution has driven the integration of computing devices in various domains, giving rise to heterogeneous and dynamic intelligent environments; together with market pressure, these pose challenges in formulating an architecture that takes advantage of contextual knowledge. In terms of architectural design, we are witnessing a transition from a centralised, monolithic view of systems to a decentralised view that incorporates the vertical and horizontal dimensions of the production environment. Therefore, this review aimed to (i) identify the requirements, (ii) find out about the representation models and context inference techniques, and (iii) identify architectural technologies, norms, models, and standards. The results observed in 25 articles made it possible to identify interoperability, automation, and decision-making as convergence points and observe the adoption of ontologies as a research area for context representation. In contrast, the discussion of context inference techniques remains open. Finally, this study presents recommendations for the design of a context-aware systems architecture that incorporates the principles of Industry 4.0 and facilitates the development of applications.

The purpose of this research is to present and discuss the methods of identifying visitors and local population in tourism studies using geotagged photos from the Flickr social network, and differentiating them according to their country of residence. This study focuses on 1,434,268 photos taken in Portugal between 2010 and 2022 and uploaded by 31,286 Flickr users. Different approaches to cleaning the database, to distinguishing tourists from locals, and to identify their country of residence were employed and discussed. After data cleaning, the photos database corresponds to 1,144,981 photos shared by 29,890 users. Using the information provided in each user’s profile and the time zone, 12,144 users (41%) were classified as visitors and 2,659 users (9%) as locals. The monthly distribution of the percentage of photos uploaded by users classified as visitors coincides with the high season of tourist activity in Portugal. The distribution of users by country of residence coincides with the main inbound markets in Portugal: Spain, United Kingdom, France and Germany. Building on a country-wide case study, the contribution of this paper is a refined understanding of the use of Flickr usergenerated content in tourism studies, proposing a frame-work to facilitate all researchers to use this data source more frequently.