Design of the technical services for knowledge graph management

The main goal of the WHOW project is to build an open and distributed knowledge graph that is capable of integrating and standardising heterogeneous data of the environmental and health domains coming from several data sources and available in different formats and structures. In particular, through identified business use cases, the project aims at creating a large knowledge base capable of linking data about water consumption and pollution with health parameters (e.g., disease spreading). The ultimate goal is fostering the creation of innovative applications, services and studies on top of the WHOW knowledge graph. Besides the business use cases that are going to be extensively described in deliverable D2.1 to be released at the end of December 2021, a key aspect of the WHOW project is the design of a fully distributed technical architecture for effective creation and publication of the WHOW open and distributed knowledge graph. The technical architecture, that can be adopted by newcomers who want to contribute to the WHOW knowledge graph, consists of two main macro-elements: - a set of semantic resources including ontologies and linked open data that are designed and produced to provide a shared semantics and standard for representing heterogeneous data of different actors and domains (i.e., water, health); - a set of software components that, using the earlier cited semantic resources, are able to provide: (i) data consumers with tools for consuming data, and related data models, via human and machine based interaction services; (ii) data providers with a technical architecture that offers software services for a sustainable data management process. This deliverable, which represents an important milestone (#7) of the project, focuses on the design of the technical architecture and describes: - a set of technical use cases that define how different types of users (data consumers and data providers) can interact with, and leverage the functionalities offered by, the WHOW technical architecture; - the functional and non-functional requirements that are derived from each technical use case and used in synergies with the business use cases of the project; - the high level view of the architecture, made up of software services and semantic resources; - a component based design of the architecture that illustrates the interfaces used in the interactions among the architectural components; - the process that is enabled in the construction of the ontologies and controlled vocabularies of the WHOW knowledge graph. The technical formalism that has been used to visually represent the design of the architecture is the Unified Modeling Language (UML), a well-known and widely used modelling language in software engineering projects. Therefore, UML use case, component and activity diagrams are introduced throughout the deliverable.