The primary goal for this Architecture, Development, and Deployment of a Knowledge Repository and Service is to address the needs of this extended community for a scalable, decentralized infrastructure for managing and disseminating operational metadata and information models, and their associated semantic constructs. The vision for the project is to re-imagine the caBIG technology environment as a more open and more readily extensible framework, one that can grow with less dependency on the centralized processes and systems that are manifest in the first generation of caBIG technology. In particular, the role of the central metadata registry, the caDSR, must be redefined as a federation of metadata registries that can be instantiated and plugged into the caBIG grid or an extended community "cloud" by any qualified entity.
The caDSR has a suite of tools and APIs that support workflows for metadata development, browsing and retrieval. In addition, the caDSR has been adapted to support the UML model-driven development paradigm adopted by caBIG. UML-defined information models such as those from the BRIDG project, caArray, caTissue, and others are each registered in the caDSR through conversion of the model elements into ISO11179 metadata constructs. This functionality, and the workflows that it supports, has evolved over an 8-year period and is now quite mature. It satisfies the current requirements for semantic representation in the current caBIG developer and user community, but it is ill-suited to serve the new requirements for decentralization and indefinite scalability in the broader health care community. The goal of this program is therefore to harvest and recycle the best elements of the first generation of caBIG metadata infrastructure, and to then incorporate those elements into a redesigned and modernized technology stack that is engineered from the start to support a federated deployment topology with far less centralized administration.
