Dissemination and Visualization of Statistical Semantic Data
It is a tool to store, link and visualize data and metadata developed in line with the most recent standards of data publication (RDF, DataCube vocabulary) to stimulate and promote data sharing, linking, reuse and analysis by both statisticians and non-statisticians, internally and externally. It helps creating interactive data visualizations easily through the web browser. The visualization tool extract the data from the repository through sparql queries.
Architecture
End user web interface
Currently: http://digital-agenda-data.eu/
Designed to provide an end user with visualization and data services, including:
- selection among available visualisation scenerios
- selection of data to be presented
- download of visualisation as jpg/bmp/png
- printing functionality (including selected filters)
- download of data as csv/xls
- social media functionality
- metadata information
Daviz (data visualisation service)
User interface to manage and configure visualisation scenerios
- Enables to access data directly through SPARQL End Point
- Provides very flexible chart configurator (customizable chart options)
- Dynamicly generate charts based on provided filtering criteria
Content registry (data storing, harvesting and maping service)
- User interface to upload and manage data
- Stores data and metadata information
- Uses standardised data vocabulary, mainly the DataCube vocabulary
- Publishes data in machine readable formats
- Provides SPARQL EndPoint
- Encompases automated harvesting services
Interaction of services
The diagram above describes the interaction of the core services:
- Import service – ensures the download of files from external repositories (such as Eurostat website) and import of these files (MS Access or MS Excel) into a temporary (staging) relational database, part of Virtuoso.
- Conversion service – ensure transformation of relational data to RDF format (records become Data Cube observations). Metadata (uploaded as Excel files) also follows this workflow in order to be converted to RDF code lists (using SKOS vocabulary).
- Harvesting service – ensure automatic download of metadata from additional vocabularies (such as SDMX, reference interval service, etc.)
- All RDF data is stored in Virtuoso quad store
- SPARQL query service – ensures retrieval of semantic data and conversion to JSON, in order to be used by the web front-end components: Chart generation service and Chart configurator (Chart administration service)
- Chart generation service – handles preparation of the web interface for public users (dashboard with filters, annotations, Highchart/map/table representations)
- Chart administration service – accessible only by the authorized users, allows the definition of new visualisations (through various combinations of supported chart types, selection of filters and chart dimensions, formatting options, etc.)
- Linked data service is a standalone component based on Elda (implementation of Linked Data API) that exposes the published datasets as Linked Data (e.g. http://semantic.digital-agenda-data.eu/dataset/digital-agenda-scoreboard-key-indicators), including slices of data, convertible to various formats such as html, json, rdf, text, xml. (e.g. http://semantic.digital-agenda-data.eu/API/data/digital-agenda-scoreboard-key-indicators/i_iuif/ind_total/pc_ind_iu3/AT.json)