Semantic query languages for knowledge-based web services in a construction context

Since the early 2000s, different frameworks were set up to enable web-based collaboration in building projects. Unfortunately, none of these initiatives was granted a long life. Recently, however, the use of web technologies in the building industry has been gaining momentum again, considered some promising technologies for reaching a more interoperable BIM practice. Specifically, this relates to (1) Linked Data and Semantic Web technologies, and (2) cloud-based applications. In order to combine these into a network of interlinked applications and datastores, an agreed-upon mechanism for automatic communication and data retrieval needs to be used. Apart from the W3C standard SPARQL, often considered too high a threshold for developers to implement, there are some recent GraphQL-based solutions that simplify the querying process and its implementation into web services. In this paper, we review two recent open source technologies based on GraphQL, that enable to query Linked Data on the web: GraphQL-LD and HyperGraphQL

A checking approach for distributed building data

Since the early 2000s, the building industry has been steadily embracing the concept of Building Information Modelling (BIM). Currently, the BIM focus lies on file-based collaboration, although with the rise of semantic web technologies, the benefits of web- and data-based collaboration for the Architecture, Engineering and Construction (AEC) industry come within reach. A web-based AEC industry that relies on Linked Data can provide various advantages compared to ‘classic’ BIM practice, e.g. regarding interdisciplinarity, linking across domains and logical reasoning. In this paper, we investigate Linked Data rule checking mechanisms on decentralised building datasets. The recent Semantic Web standard Shapes Constraint Language (SHACL) is used to check a Linked Data building model that is hosted on multiple data pods. After a short introduction to Linked Building Data and rule checking approaches, a minimal distributed building model will be checked with basic SHACL patterns, generating a report to inform both end users and tools. In this case study, we make use of the Social Linked Data (Solid) ecosystem, a set of conventions and tools for creating decentralised applications

Querying heterogeneous linked building datasets with context-expanded GraphQL queries

Linked Data in the construction industry is a topic gaining serious interest over the last years. However, this interest remains largely academic and has not sparked much adoption of web technologies in the field. To nourish adoption of Linked Data in practice, access to the data has to be made more easy. SPARQL, the recommended RDF query language, has proven very powerful for retrieving and updating RDF datasets. However, due to its verbosity and complexity, it is often considered a threshold for developers to implement in their tools. In this paper, we compare SPARQL with Linked Data querying languages that extend the GraphQL syntax, in context of querying building datasets: HyperGraphQL and GraphQL-LD. Since it went open source in 2015, GraphQL has been adopted by a large community of developers, partly due to its elegance and conciseness. As a use case, the queries are performed on an RDF-based multi-model that relies on the recent ISO standard ICDD (ISO 21597). ICDD interlinks information on a sub-document identifier level, based on OWL. It is aimed at the industry in that it adds a layer of Linked Data to documentation formats that are still widely used in practice: IFC, spreadsheets, imagery etc. Therefore, it is considered a tuned use case for comparing these different RDF query languages