Bridging Web APIs and Linked Data with SPARQL Micro-Services

International audienceWeb APIs are a prominent source of machine-readable information that remains insufficiently connected to the Web of Data. To enable automatic combination of Linked Data (LD) interfaces and Web APIs, we present the SPARQL Micro-Service architecture. A SPARQL micro-service is a lightweight SPARQL endpoint that provides access to a small, resource-centric, virtual graph, while dynamically assigning stable, dereferenceable URIs to Web API resources that do not have URIs in the first place. We believe that the emergence of an ecosystem of SPARQL micro-services could enable LD-based applications to glean pieces of data from a wealth of distributed, scalable and reliable services from independent providers. We describe an experimentation where we dynamically augment biodiversity-related LD resources with data from Flickr, MusicBrainz and the Macauley scientific media library

Federating and querying heterogeneous and distributed Web APIs and triple stores

Today's international corporations such as BASF, a leading company in the crop protection industry, produce and consume more and more data that are often fragmented and accessible through Web APIs. In addition, part of the proprietary and public data of BASF's interest are stored in triple stores and accessible with the SPARQL query language. Homogenizing the data access modes and the underlying semantics of the data without modifying or replicating the original data sources become important requirements to achieve data integration and interoperability. In this work, we propose a federated data integration architecture within an industrial setup, that relies on an ontology-based data access method. Our performance evaluation in terms of query response time showed that most queries can be answered in under 1 second

Enabling discoverable trusted services for highly dynamic decentralized workflows

Fifth generation (5G) mobile networks will revolutionize edge-based computing by providing fast and reliable network capabilities to remote sensors, devices and microservices. This heralds new opportunities for researchers, allowing remote instrumentation and analytic capabilities to be as accessible as local resources. The increased availability of remote data and services presents new opportunities for collaboration, yet introduces challenges for workflow orchestration, which will need to adapt to consider an increased choice of available services, including those from trusted partners and the wider community. In this paper we outline a workflow approach that provides decentralized discovery and orchestration of verifiably trustable services in support of multi-party operations. We base this work on the adoption of standardised data models and protocols emerging from hypermedia research, which has demonstrated success in using combinations of Linked Data, Web of Things (WoT) and semantic technologies to provide mechanisms for autonomous goal-directed agents to discover, execute and reuse new heterogeneous resources and behaviours in large-scale, dynamic environments. We adopt Verifiable Credentials (VCs) to securely share information amongst peers based on prior service usage in a cryptographically secure and tamperproof way, providing a trust-based framework for ratifying service qualities. Collating these new service description channels and integrating with existing decentralized workflow research based on vector symbolic architecture (VSA) provides an enhanced semantic search space for efficient and trusted service discovery that will be necessary for 5G edge-computing environments

Enabling Automatic Discovery and Querying of Web APIs at Web Scale using Linked Data Standards

International audienceTo help in making sense of the ever-increasing number of data sources available on the Web, in this article we tackle the problem of enabling automatic discovery and querying of data sources at Web scale. To pursue this goal, we suggest to (1) provision rich descriptions of data sources and query services thereof, (2) leverage the power of Web search engines to discover data sources, and (3) rely on simple, well-adopted standards that come with extensive tooling. We apply these principles to the concrete case of SPARQL micro-services that aim at querying Web APIs using SPARQL. The proposed solution leverages SPARQL Service Description, SHACL, DCAT, VoID, Schema.org and Hydra to express a rich functional description that allows a software agent to decide whether a micro-service can help in carrying out a certain task. This description can be dynamically transformed into a Web page embedding rich markup data. This Web page is both a human-friendly documentation and a machine-readable description that makes it possible for humans and machines alike to discover and invoke SPARQL micro-services at Web scale, as if they were just another data source. We report on a prototype implementation that is available on-line for test purposes, and that can be effectively discovered using Google's Dataset Search engine

NarDis:Narrativizing Disruption -How exploratory search can support media researchers to interpret ‘disruptive’ media events as lucid narratives

This project investigates how CLARIAH’s exploratory search and linked open data (LO D) browser DIVE+ supports media researchers to construct narratives about events, especially ‘disruptive’ events such as terrorist attacks and natural disasters. This project approaches this question by conducting user studies to examine how researchers use and create narratives with exploratory search tools, particularly DIVE+, to understand media events. These user studies were organized as workshops (using co-creation as an iterative approach to map search practices and storytelling data, including: focus groups & interviews; tasks & talk aloud protocols; surveys/questionnaires; and research diaries) and included more than 100 (digital) humanities researchers across Europe. Insights from these workshops show that exploratory search does facilitate the development of new research questions around disruptive events. DIVE+ triggers academic curiosity, by suggesting alternative connections between entities. Beside learning about research practices of (digital) humanities researchers and how these can be supported with digital tools, the pilot also culminated in improvements to the DIVE+ browser. The pilot helped optimize the browser’s functionalities, making it possible for users to annotate paths of search narratives, and save these in CLARIAH’s overarching, personalised, user space. The pilot was widely promoted at (inter)national conferences, and DIVE+ won the international LO DLAM (Linked Open Data in Libraries, Archives and Museums) Challenge Grand Prize in Venice (2017)

Integration of Web APIs and Linked Data Using SPARQL Micro-Services - Application to Biodiversity Use Cases

International audienceIn recent years, Web APIs have become a de facto standard for exchanging machine-readable data on the Web. Despite this success, however, they often fail in making resource descriptions interoperable due to the fact that they rely on proprietary vocabularies that lack formal semantics.The Linked Data principles similarly seek the massive publication of data on the Web, yet with the specific goal of ensuring semantic interoperability.Given their complementary goals, it is commonly admitted that cross-fertilization could stem from the automatic combination of Linked Data and Web APIs. Towards this goal, in this paper we leverage the micro-service architectural principles to define a SPARQL Micro-Service architecture, aimed at querying Web APIs using SPARQL. A SPARQL micro-service is a lightweight SPARQL endpoint that provides access to a small, resource-centric, virtual graph. In this context, we argue that full SPARQL Query expressiveness can be supported efficiently without jeopardizing servers availability.Furthermore, we demonstrate how this architecture can be used to dynamically assign dereferenceable URIs to Web API resources that do not have URIs beforehand, thus literally “bringing” Web APIs into the Web of Data. We believe that the emergence of an ecosystem of SPARQL micro-services published by independent providers would enable Linked Data-based applications to easily glean pieces of data from a wealth of distributed, scalable, and reliable services. We describe a working prototype implementation and we finally illustrate the use of SPARQL micro-services in the context of two real-life use cases related to the biodiversity domain, developed in collaboration with the French National Museum of Natural History

Adding semantic annotations into (Geospatial) RESTful services

In this paper the authors present an approach for the semantic annotation of RESTful services in the geospatial domain. Their approach automates some stages of the annotation process, by using a combination of resources and services: a cross-domain knowledge base like DBpedia, two domain ontologies like GeoNames and the WGS84 vocabulary, and suggestion and synonym services. The authors’ approach has been successfully evaluated with a set of geospatial RESTful services obtained from ProgrammableWeb.com, where geospatial services account for a third of the total amount of services available in this registry