[Knowledge Base]

In order to answer VisKo queries, the VisKo query answering system must know about a set of visualization services that it can chain together to form executable pipelines that in turn generate visualizations. The services are described in RDF using the vocabulary defined by our ontologies and this collection of RDF is refered to as the knowledge base. The RDF descriptions are generated by packages. This page better describes VisKo knowledge bases using visualizations that were actually generated by VisKo itself!

Data Paths Perspective

One thing a VisKo knowledge base can describe is possible data transformation paths. The following visualization presents a snapshot of the knowledge base supporting UTEP's VisKo server. Each node represents a kind of data specified by a format and data type (e.g., netCDF [Variable_with_Time]. The directed arcs between data convey that the data can be transformed to another data by way of some visualization service. The services are left out of the visualization so that the view doesn't become crowded and unreadable.

Node Color Viewer Readable
Red Not directly readable
Blue Directly readable by some viewer

Operator Paths Perspective

Yet another perspective of the knoweldge base is the operators paths view show below. In this view, nodes represent different visualization services and a edge between them means that the output of some service can be accepted as input by another service and so they can be chained together. Esentially, you are looking at all the possible pipelines that the UTEP VisKo server can generate at the time of this snapshot. The nodes are color coded to show what type of operator they are in terms of the VisKo Operator Ontology. Valid visualization pipelines must contain at least one Mapper and end at a Viewer, thus only a subset of the paths shown represent legal visualziation pipelines.

Node Color Operator Type
Purple Generic Data Transformer
Yellow Mapper
White Viewer

Raw RDF Form

UTEP's RDF Knowledge Base hosted on GitHub

Contributing to a Knowledge Base

RDF descriptions of services can be generated by installing packages. Please visit this page to learn how to create packages.

Copyright @2011, 2012 OpenVisKo.org