]> WP1 – Requirements, Design and LOD2 Stack Prototype Objectives of this work package are: (1) to develop use case specifications and to collect user requirements by consulting the communities of practice relevant for the LOD2 use cases and additional prospective application scenarios, (2) to identify technical constraints as well as standards, (3) to produce the architecture and the LOD2 Stack design and (4) to produce an early prototype of the LOD2 Stack in the first year. 1 D1.1 – Common requirements analysis and specification 2011-02-28 2010-12-31 2011-02-28 2011-08-31 A1 - Fundamental and integration activities Fundamental and integration activities will form the ground work which provides the necessary infrastructure and integration methodology. In particular, these types of activities serve the following purposes: <ol> <li>the efficient and uniform use of existing and complementary technology, and,</li> <li>smooth integration of the various modules, components and subsystems.</li> </ol> The integration methodology and infrastructure will ensure that the components are combined in the right way. These activities also provide a basis for the easy development of real-world solutions that integrate the various project outcomes. M1.1 – Completed requirements specification and system design This milestone will show that the requirements for the three LOD2 use cases have been gathered. From these requirements, relevant standards and state-of-the-art analysis a comprehensive system design specifying and describing the LOD2 Stack will be obtained. The LOD2 Stack design lays the foundation for the implementation of the first LOD2 Stack prototype. 2011-02-28 This milestone results in a first revision of the LOD2 Stack, which will build the basis for the iterative refinement and functionality additions throughout the project. The prototype implementation of the LOD2 Stack will also serve as an early evaluation and assessment environment for its application within the three LOD2 use case scenarios. 2011-08-31 WP2 – Storing and Querying Very Large Knowledge bases This work package implements the LOD2 knowledge store component needed for managing the Web of Linked Data as a vast database. The starting point is OpenLink Virtuoso and MonetDB on the database side and Sindice on the information retrieval side. The present data volumes handled are around 10 billion RDF triples and the target is over the 1 trillion triples. The approach is scale-out out (physical) complemented with significant scalability improvements in the RDF engine (logical): Physically, when data grows, servers can be added and data redistributed without interruption of service, ibid for server failure. Logically, there is no point answering questions nobody is asking. Therefore the base data is kept as RDF with text indexing and search ranking. Additional inference results or indices for caching joins are made as a by-product of querying; further exploitation of such (partially) materialized inferences through the graph at run-time is to exploit structural correlations in the graphs. 2